¿Qué sabemos del origen del COVID-19 tres años después? / What do we know about the origin of COVID-19 three years later?

More than three years have passed since the first case of a new coronavirus infection (SARS-CoV-2) in the city of Wuhan (Hubei, China). The Wuhan Institute of Virology was founded in that city in 1956 and the country’s first biosafety level 4 laboratory opened within that center in 2015. The coincidence that the first cases of infection emerged in the city where the virology institute’s headquarters is located, the failure to 100% identify the virus’ RNA in any of the coronaviruses isolated in bats, and the lack of evidence on a possible intermediate animal host in the contagion’s transmission make it so that at present, there are doubts about the real origin of SARS-CoV-2. This article will review two theories: SARS-CoV-2 as a virus of zoonotic origin or as a leak from the high-level biosafety laboratory in Wuhan (AU)

Han pasado más de tres años desde el primer caso de infección por un nuevo coronavirus (SARS-CoV-2) en la ciudad de Wuhan (Hubei, China). En esta misma ciudad se fundó en 1956 el Instituto de Virología de Wuhan y en 2015 abrieron en este centro el primer laboratorio de bioseguridad de nivel 4 del país. La coincidencia de ciudad entre los primeros casos de infección y la sede del instituto de virología, sumados a la fallida identificación del RNA del virus al 100% en ninguno de los coronavirus aislados en murciélagos, junto con la falta de evidencia sobre el posible animal intermediario en la transmisión de contagio, hacen que a fecha de hoy surjan dudas sobre el origen real del SARS-CoV-2. En este artículo revisaremos dos teorías, el SARS-CoV-2 como origen zoonótico o como escape del laboratorio de alta bioseguridad en Wuhan (AU)

Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 15 (21 April 2023)

[WEEKLY SUMMARY]. North America: Influenza activity has been on the rise, with Mexico reporting an increase in activity. Influenza B (Victoria lineage in cases where it has been determined) and influenza A (H1N1)pdm09 have been circulating concurrently. Respiratory syncytial virus (RSV) activity has remained low, while SARS-CoV-2 activity has remained at moderate levels. Caribbean: An increase in influenza activity has been detected. Influenza B Victoria lineage has predominantly circulated. The countries where increases in activity have been detected are Belize and Jamaica. RSV and SARS-CoV-2 activity has remained low. Central America: Influenza activity has remained stable, with predominance of influenza A (H1N1)pdm09 and influenza B Victoria, and to a lesser extent, influenza A (H3N2) circulation. The countries with the highest activity have been Costa Rica, El Salvador, and Guatemala. RSV and SARS-CoV-2 activity has remained low. Andean Countries: Influenza activity has increased, especially in Bolivia. Circulation has also been detected in Ecuador and Peru, but to a lesser extent. Influenza A (H1N1)pdm09 has predominated, although some detections of influenza A (H3N2) and influenza B Victoria have also been reported. RSV activity remains low, and SARS-CoV-2 activity remains at intermediate levels. Brazil and Southern Cone: Influenza activity has increased, especially in Chile and Paraguay, with circulation of influenza A (H1N1)pdm09 and influenza B Victoria. RSV and SARS-CoV-2 activity remains stable at low levels. Global: Influenza detections decreased steeply in January after a peak in late 2022. Detections in 2022 were predominantly influenza A(H3N2). After the end of January 2023, activity increased again with a higher proportion of influenza A(H1N1)pdm09 and B virus detections until a peak around week 10, after which detections decreased. In Europe, overall influenza detections decreased, and influenza positivity from sentinel sites decreased to 16% but remained above the epidemic threshold at the regional level. Of 41 countries, 13 reported moderate intensity, with the remainder reporting low or below baseline intensity. Out of 40 countries, 20 continued to report widespread activity. Overall, influenza B viruses predominated in both sentinel and non-sentinel surveillance, as all subregions experienced a wave of influenza B activity after an initial influenza A wave. Of the few influenza A viruses detected, most were influenza A(H1N1)pdm09. Influenza detections decreased or were stable in most countries except Lithuania and Norway, where slight increases were reported. In Central Asia, sporadic influenza detections were reported in Kazakhstan (influenza A(H1N1)pdm09) and Tajikistan. In Northern Africa, influenza detections were very low. In Western Asia, influenza activity decreased but continued to be reported in some countries with detections of all seasonal influenza subtypes. In East Asia, influenza activity continued to be driven predominantly by A(H1N1)pdm09 detections in China, which appeared to reach a peak and decrease slightly. Slight increases in some indicators of influenza activity were reported in China, the Hong Kong Special Administrative Region (SAR), China, and the Republic of Korea. In tropical Africa, influenza activity increased in some countries of Western Africa, while detections were low across reporting countries in Middle and Eastern Africa. In Southern Asia, influenza activity remained low, with influenza A(H3N2) and B/Victoria lineage viruses predominating. In South-East Asia, influenza activity remained elevated mainly due to influenza B detections in Malaysia and influenza A(H3N2) in Singapore. In the temperate zones of the southern hemisphere, influenza activity remained low; however, influenza activity increased slightly in Australia. RSV activity was generally low or decreasing globally except in Australia, New Zealand, and South Africa. SARS-CoV-2 positivity from sentinel surveillance decreased from around 20% to 12% globally. Activity decreased slightly to about 20% in the Americas but increased to just below 20% in the Eastern Mediterranean Region. Activity remained around or below 10% in the other regions. SARS-CoV-2 positivity from non-sentinel surveillance was reported at around 23% globally. Avian Influenza: A summary of the avian influenza situation in the region, case management and recommendations are available at Epidemiological alerts and updates | PAHO/WHO | Pan American Health Organization (paho.org)

Biweekly COVID-19 Epidemiological Update: Issue 62 (19 April 2023) 

Since the onset of the pandemic in 2020 and up to 15 April 2023, a cumulative total of 763 million COVID-19 cases including 6.9 million deaths were reported from all six WHO regions. During epidemiological week (EW) 14 & 15, cases increased in SEARO (215.8%), EMRO (29.7%), and WPRO (10.6%) and deaths decreased in 4 regions while they increased in SEARO (127.0%) and EMRO (80.1%) compared to the previous 2 weeks. In the region of the Americas, 365,747 cases and -5,060 deaths were reported in EW 14 & 15 – a -33.6% decrease in cases and -378.9% decrease in deaths compared to the previous 2 weeks. Please note, the negative number in deaths for EW 14&15 in the region of the Americas is due to a retro-adjustments done by Chile and Canada for cumulative deaths since 2020. At the subregional level, COVID-19 cases decreased in all subregions. Deaths increased in Caribbean and Atlantic Ocean Islands (21.3%). Among countries/territories in the region with available data, biweekly COVID-19 hospitalizations increased in eighteen countries and territories (range: 6.3% - 547.7%) during EW 14 & 15 compared to the previous 2 weeks. Among countries and territories with available data, biweekly COVID-19 ICU admissions increased in nine countries and territories (range: 8.8% - 1,350%).

Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 14 (14 April 2023)

[WEEKLY SUMMARY]. North America: Influenza virus activity decreased overall, with the predominance of influenza B viruses. All seasonal influenza subtypes were detected. SARS-CoV-2 circulated at moderate levels, and RSV activity was very low. Influenza activity was low in Canada and the United States. Influenza activity recently increased in Mexico, at low-intensity levels, with elevated SARS-CoV-2 and RSV activity, but decreasing. Caribbean: Influenza percent positivity increased, driven mainly by influenza B/Victoria lineage viruses. In addition, the influenza A(H1N1)pdm09 virus co-circulated. In Belize and Jamaica, influenza activity was increased, with influenza B/Victoria lineage circulation. In addition, SARI cases were raised in Jamaica, mainly in children under five. Overall, SARS-CoV-2 and RSV activity were low in the subregion. Central America: Influenza percent positivity increased, with influenza A(H1N1)pdm09 virus predominance and co-circulation of influenza A(H3N2) and B/Victoria. Influenza activity was moderate in Guatemala with influenza A(H3N2) and B/Victoria viruses co-circulation. Honduras and Panama reported low-intensity levels of influenza B (lineage undetermined). SARS-CoV-2 percent positivity dropped in the subregion, except in Costa Rica and Panama. In Guatemala, RSV activity increased, remaining low in other countries. Andean: Influenza activity was low, predominating influenza A(H1N1)pdm09 viruses; influenza B/Victoria and A(H3N2) viruses co-circulated. Venezuela reported increased influenza activity, with A(H1N1)pdm09 circulation. SARI cases / 100 hospitalizations were at moderate levels, with 12% positive for influenza in Bolivia. In the subregion, SARS-CoV-2 was low, with increasing activity in Ecuador and Peru. RSV activity was low, but an increasing trend was observed in Bolivia and Colombia. Brazil and Southern Cone: Influenza activity was low but increasing, with influenza B viruses more frequently detected and all seasonal influenza subtypes detected. Chile and Paraguay reported increasing influenza activity, with SARI cases at low levels primarily associated with SARS-CoV-2 and RSV viruses. Increased SARS-CoV-2 activity was reported in Brazil, Chile, and Paraguay. RSV activity was low in the subregion. Global: Influenza detections decreased steeply in January after a peak in late 2022. Detections in 2022 were predominantly influenza A(H3N2). After the end of January 2023, activity increased again with a higher proportion of influenza A(H1N1)pdm09 and B virus detections until a peak around week 10, after which detections decreased. In Europe, overall influenza detections decreased, and influenza positivity from sentinel sites decreased to 16% but remained above the epidemic threshold at the regional level. Of 41 countries, 13 reported moderate intensity, with the remainder reporting low or below baseline intensity. Out of 40 countries, 20 continued to report widespread activity. Overall, influenza B viruses predominated in both sentinel and non-sentinel surveillance, as all subregions experienced a wave of influenza B activity after an initial influenza A wave. Of the few influenza A viruses detected, most were influenza A(H1N1)pdm09. Influenza detections decreased or were stable in most countries except Lithuania and Norway, where slight increases were reported. In Central Asia, sporadic influenza detections were reported in Kazakhstan (influenza A(H1N1)pdm09) and Tajikistan. In Northern Africa, influenza detections were very low. In Western Asia, influenza activity decreased but continued to be reported in some countries with detections of all seasonal influenza subtypes. In East Asia, influenza activity continued to be driven predominantly by A(H1N1)pdm09 detections in China, which appeared to reach a peak and decrease slightly. Slight increases in some indicators of influenza activity were reported in China, the Hong Kong Special Administrative Region (SAR), China, and the Republic of Korea. In tropical Africa, influenza activity increased in some countries of Western Africa, while detections were low across reporting countries in Middle and Eastern Africa. In Southern Asia, influenza activity remained low, with influenza A(H3N2) and B/Victoria lineage viruses predominating. In South-East Asia, influenza activity remained elevated mainly due to influenza B detections in Malaysia and influenza A(H3N2) in Singapore. In the temperate zones of the southern hemisphere, influenza activity remained low; however, influenza activity increased slightly in Australia. RSV activity was generally low or decreasing globally except in Australia, New Zealand, and South Africa. SARS-CoV-2 positivity from sentinel surveillance decreased from around 20% to 12% globally. Activity decreased slightly to about 20% in the Americas but increased to just below 20% in the Eastern Mediterranean Region. Activity remained around or below 10% in the other regions. SARS-CoV-2 positivity from non-sentinel surveillance was reported at around 23% globally. Avian Influenza: A summary of the avian influenza situation in the region, case management and recommendations are available at Epidemiological alerts and updates | PAHO/WHO | Pan American Health Organization (paho.org)

[RESUMEN SEMANAL]. América del Norte: la actividad del virus de la influenza disminuyó en general, con predominio de los virus de la influenza B. Se detectaron todos los subtipos de influenza estacional. El SARS-CoV-2 circuló a niveles moderados y la actividad del VRS estuvo muy baja. La actividad de la influenza estuvo baja en Canadá y los Estados Unidos. La actividad de la influenza aumentó recientemente en México, en niveles de baja intensidad, con actividad elevada de SARS-CoV‑2 y de VRS, pero con tendencia a disminuir. Caribe: el porcentaje de positividad de la influenza aumentó, impulsado principalmente por los virus influenza B linaje Victoria. Además, circuló concurrentemente el virus de la influenza A(H1N1)pdm09. En Belice y Jamaica se incrementó la actividad de la influenza, con circulación del linaje influenza B/Victoria. Además, en Jamaica se incrementaron los casos de IRAG, principalmente en niños menores de cinco años. En general, la actividad de SARS-CoV-2 y del VRS estuvo baja en la subregión. América Central: el porcentaje de positividad de influenza aumentó, con predominio del virus influenza A(H1N1)pdm09 y circulación concurrente de influenza A(H3N2) y B/Victoria La actividad del virus de la influenza estuvo moderada en Guatemala con circulación concurrente de influenza A(H3N2) y B linaje Victoria. Honduras y Panamá reportaron influenza B (linaje indeterminado) en niveles de baja intensidad. El porcentaje de positividad de SARS-CoV-2 disminuyó en la subregión, excepto en Costa Rica y Panamá. En Guatemala, la actividad del VRS aumentó, permaneciendo baja en los otros países. Países Andinos: la actividad del virus de la influenza estuvo baja, predominando los virus influenza A(H1N1)pdm09; circulación concurrentemente los virus influenza B/Victoria y A(H3N2). Venezuela reportó un aumento de la actividad del virus de la influenza, con circulación de A(H1N1)pdm09. El número de casos de IRAG por cada 100 hospitalizaciones se ubicó en niveles moderados, con 12 % de positivos para influenza en Bolivia. En la subregión, la actividad del SARS-CoV-2 estuvo baja, con actividad creciente en Ecuador y Perú. La actividad del VRS estuvo baja, pero se observó una tendencia creciente en Bolivia y Colombia. Brasil y Cono Sur: la actividad de la influenza estuvo baja pero con tendencia al aumento, con los virus influenza B detectados con mayor frecuencia y con registro de todos los subtipos de influenza estacional. Chile y Paraguay reportaron un aumento de la actividad de la influenza, con el número de casos de IRAG en niveles bajos asociados principalmente con los virus SARS-CoV-2 y VRS. Se informó una mayor actividad del SARS-CoV-2 en Brasil, Chile y Paraguay. La actividad del VRS estuvo baja en la subregión. Global: después de un pico a fines de 2022 las detecciones de influenza disminuyeron marcadamente en enero para volver a aumentar a fines de enero de 2023, con una mayor proporción de influenza A(H1N1)pdm09 e influenza B y alcanzó un pico cerca de la semana diez, después las detecciones disminuyeron. En Europa, las detecciones de influenza disminuyeron y la positividad en los sitios centinela disminuyó al 16 %, pero se mantuvo encima del umbral epidémico a nivel regional. De 41 países, 13 informaron una intensidad moderada, y el resto intensidad baja en niveles basales. De 40 países, 20 continuaron reportando actividad generalizada. En general, los virus influenza B predominaron en la vigilancia centinela y no centinela, debido a que todas las subregiones tuvieron una ola de influenza B después de una ola de influenza A. De las pocas detecciones de influenza A, la mayoría eran influenza A(H1N1)pdm09. En la mayoría de los países la detección de influenza disminuyó o se mantuvo estable, excepto en Lituania y Noruega, los cuales reportaron ligeros aumentos. En Asia central se reportó detecciones esporádicas de influenza en Kazajstán (influenza A(H1N1)pdm09) y Tayikistán. En el norte de África las detecciones de influenza estuvieron muy bajas. En Asia occidental la actividad de la influenza disminuyó, pero algunos países continuaron notificando detecciones de todos los subtipos de influenza estacional. En el este de Asia la actividad de la influenza estuvo impulsada predominantemente por las detecciones de A(H1N1)pdm09 en China, que pareció alcanzar un pico y disminuir levemente. Hubo ligeros aumentos en algunos indicadores de la actividad de la influenza en China, la Región Administrativa Especial (SAR) de Hong Kong, China y la República de Corea. En África tropical la actividad de la influenza aumentó en algunos países de África occidental, mientras que estuvo baja en los países que reportaron de África central y oriental. En el sur de Asia, la actividad de la influenza se mantuvo baja, con predominio de influenza A(H3N2) y B/Victoria. En el sudeste asiático la actividad de la influenza se mantuvo elevada principalmente debido a las detecciones de influenza B en Malasia e influenza A(H3N2) en Singapur. En las zonas templadas del hemisferio sur, la actividad de la influenza se mantuvo baja; sin embargo, aumentó ligeramente en Australia. En la vigilancia centinela la positividad de SARS-CoV-2 disminuyó de alrededor del 20 % al 12 %. La actividad disminuyó levemente a alrededor del 20% en las Américas, pero aumentó a poco menos del 20% en la Región del Mediterráneo Oriental. La actividad se mantuvo alrededor o por debajo del 10 % en las demás regiones. Se reportó una positividad de SARS-CoV-2 de la vigilancia no centinela en alrededor del 23% a nivel mundial. Influenza Aviar: el resumen sobre la situación epidemiológica de influenza aviar en la región, manejo de los casos y recomendaciones se encuentran disponibles en Alertas y actualizaciones epidemiológicas | OPS/OMS | Organización Panamericana de la Salud (paho.org)

Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 13 (7 April 2023)

[WEEKLY SUMMARY] North America: Influenza virus activity was low in the sub-region, with the predominance of influenza B viruses and all seasonal influenza subtypes detected. SARS-CoV-2 activity was at moderate levels, with low RSV activity. Canada and the United States reported low influenza activity, while Mexico recorded increased influenza activity, although, at a low-intensity level; SARS-CoV-2 and RSV activity were increased. Caribbean: Influenza percent positivity was moderate, driven by influenza B/Victoria lineage viruses; influenza A(H1N1)pdm09 virus co-circulated. In Belize, influenza activity was increased, with influenza B/Victoria lineage and influenza A(H3N2) co-circulation, at low-intensity levels. SARS-CoV-2 and RSV activity were low in the subregion. Central America: Influenza activity was moderate, with influenza A and B viruses detected equally. All seasonal influenza subtypes were detected. El Salvador and Guatemala reported increased influenza activity at moderate-intensity levels, with the circulation of influenza B/Victoria in El Salvador and all seasonal influenza subtypes in Guatemala. Severity indicators were at low levels. Influenza B (lineage undetermined) viruses continued high in Honduras, with SARI activity at baseline levels. SARS-CoV-2 percent positivity dropped in the subregion, except in Costa Rica. RSV activity was low overall. Andean: Influenza activity was low, predominating influenza A(H1N1)pdm09 viruses; influenza B/Victoria and A(H3N2) viruses co-circulated. Overall, influenza detections were very low across reporting countries. SARI activity was increased in Bolivia, with 11.7% influenza-associated SARI. SARS-CoV-2 and RSV activity were low. Brazil and Southern Cone: Influenza activity was low, with a slowly increasing trend in recent weeks. Influenza B viruses were more frequently detected, and all seasonal influenza subtypes were detected. In Chile, influenza activity increased to low-intensity levels, and SARI activity was low. Increased SARS-CoV-2 activity was reported in Brazil and Chile. RSV was low among reporting countries. Avian Influenza: A summary of the avian influenza situation in the region, case management and recommendations are available at Epidemiological alerts and updates | PAHO/WHO | Pan American Health Organization (paho.org)

[RESUMEN SEMANAL]. América del Norte: la actividad del virus de la influenza estuvo baja en la subregión, con predominio de los virus influenza B y detección de todos los subtipos de influenza estacional. La actividad del SARS-CoV-2 estuvo en niveles moderados, con baja actividad de VRS. Canadá y los Estados Unidos reportaron baja actividad de influenza, mientras que México registró aumento en la actividad del virus de la influenza, aunque, en un nivel de baja intensidad; la actividad del SARS-CoV-2 y del VRS estuvo aumentada. Caribe: el porcentaje de positividad del virus de la influenza estuvo moderado, debido a las detecciones de influenza B linaje Victoria; con circulación concurrente de influenza A(H1N1)pdm09. En Belice, la actividad del virus de la influenza aumentó, con circulación concurrente de influenza B, linaje Victoria e influenza A(H3N2), en niveles de baja intensidad. La actividad del SARS-CoV-2 y del VRS estuvo baja en la subregión. América Central: la actividad del virus de la influenza estuvo moderada, con igual número de detecciones de los virus influenza A y B. Se detectaron todos los subtipos de influenza estacional. El Salvador y Guatemala reportaron aumento de la actividad del virus de la influenza en niveles de intensidad moderada, con circulación de influenza B, linaje Victoria en El Salvador, y todos los subtipos de influenza estacional en Guatemala. Los indicadores de gravedad estuvieron en niveles bajos. Las detecciones de influenza B (linaje indeterminado) continuaron altas en Honduras, con una actividad de las IRAG en los niveles basales. El porcentaje de positividad del SARS-CoV-2 disminuyó en la subregión, excepto en Costa Rica. La actividad del VRS estuvo baja en general. Países Andinos: la actividad del virus de la influenza estuvo baja, predominando los virus influenza A(H1N1)pdm09; con circulación concurrente de los virus influenza B/Victoria y A(H3N2). En general, las detecciones de influenza estuvieron muy bajas en los países que reportaron. La actividad de la IRAG estuvo aumentada en Bolivia, con un 11,7 % de los casos de IRAG asociados al virus de la influenza. La actividad del SARS-CoV-2 y del VRS estuvo baja. Brasil y Cono Sur: la actividad del virus de la influenza estuvo baja, con una tendencia lenta al aumento en las últimas semanas. Los virus influenza B se detectaron con mayor frecuencia y se detectaron todos los subtipos de influenza estacional. En Chile, la actividad del virus de la influenza aumentó en niveles de baja intensidad y la actividad de las IRAG estuvo baja. Se reportó una mayor actividad del SARS-CoV-2 en Brasil y Chile. Las detecciones del VRS estuvieron bajas en los países que reportaron. Influenza Aviar: el resumen sobre la situación epidemiológica de influenza aviar en la región, manejo de los casos y recomendaciones se encuentran disponibles en Alertas y actualizaciones epidemiológicas | OPS/OMS | Organización Panamericana de la Salud (paho.org)

Weekly COVID-19 Epidemiological Update: Issue 61 (5 April 2023)

Since the onset of the pandemic in 2020 and up to 05 April 2023, a cumulative total of approximately 762 million COVID-19 cases including 6.9 million deaths were reported from all six WHO regions. During epidemiological week (EW) 13, cases decreased in four regions while they increased in SEARO and AMRO, and deaths decreased in four regions while they increased in SEARO and AFRO. In the region of the Americas, 277,830 cases and -1,044 deaths were reported in EW 13 – a 2.4% increase in cases and -136.8% decrease in deaths compared to the previous week. Please note, the negative number in deaths for EW 13 in the region of the Americas is due to a retro-adjustment done by Chile for 2020 cumulative deaths. At the subregional level, COVID-19 cases increased in one subregion – North America (12% increase). Deaths increased in one subregion – Central America (5.3% increase). The overall weekly case notification rate for the region of the Americas was 27.2 cases per 100,000 population during EW 13 (26.5 the previous week). Between EW 13 and 12, the 14-day COVID-19 death rate was 1.8 deaths per 1 million population (5.2 the previous two weeks). Among 18 countries/territories in the region with available data, COVID-19 hospitalizations increased in 11 countries and territories (range: 3.4% - 133.3%) during EW 13 compared to the previous week. Among 14 countries and territories with available data, COVID-19 ICU admissions increased in 4 countries and territories (range: 18.5% - 100%).

Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 12 (31 March 2023)

[WEEKLY SUMMARY]. North America: Influenza virus activity decreased throughout the sub-region, with the predominance of influenza B viruses. All seasonal influenza subtypes were detected. SARS-CoV-2 circulates at moderate levels, while RSV activity was generally low. Influenza activity was low in Canada and the United States. In Mexico, influenza activity has recently increased at a low-intensity level, with elevated SARS-CoV-2 and RSV activity. Caribbean: Influenza percent positivity was moderate, driven mainly by influenza B/Victoria lineage viruses. In addition, the influenza A(H1N1)pdm09 virus co-circulated. In Belize, influenza activity was increased, with influenza B/Victoria lineage and influenza A(H1N1)pdm09 co-circulation. Overall, SARS-CoV-2 and RSV activity were low in the subregion. Central America: Influenza activity was moderate, with influenza B/Victoria virus predominance and co-circulation of influenza A(H3N2) and A(H1N1)pdm09. In El Salvador, influenza activity was elevated due to influenza B/Victoria and A(H3N2) viruses, and Guatemala reported increased activity with all seasonal subtypes detected. In Honduras, influenza activity was increased due to influenza B viruses. SARS-CoV-2 percent positivity dropped in the subregion, except in Costa Rica. RSV activity was low overall. Andean: Influenza activity was low, predominating influenza A(H1N1)pdm09 viruses; influenza B/Victoria and A(H3N2) viruses co-circulated. Bolivia reported increased influenza activity, with SARI cases / 100 hospitalizations at moderate levels and 14% positive for influenza. In the subregion, SARS-CoV-2 and RSV activity were low overall. Brazil and Southern Cone: Influenza activity was low, with influenza B viruses more frequently detected and all seasonal influenza subtypes detected. Increased SARS-CoV-2 activity was reported in Brazil, Chile, and Paraguay, while RSV was elevated in Brazil. Global: Influenza activity decreased following a peak in late 2022 but increased again in late February to March with an increase in influenza B virus activity. During this reporting period, influenza A viruses predominated, with a larger proportion of A(H1N1)pdm09 viruses detected among the subtyped influenza A viruses. In Europe, overall influenza detections decreased, and influenza positivity from sentinel sites was stable and remained above the epidemic threshold at the regional level. Out of 37 countries, 16 reported medium intensity, with the remainder reporting low or below baseline intensity. Eighteen of 36 countries reported widespread activity. Overall, influenza B viruses predominated in both sentinel and non-sentinel surveillance, as all subregions experienced a wave of influenza B activity after an initial influenza A wave. In Central Asia, influenza activity decreased. In Northern Africa, influenza detections were very low across reporting countries. In Western Asia, influenza activity continued to be reported in some countries with detections of all seasonal influenza subtypes. In East Asia, influenza activity of predominantly A(H1N1)pdm09 steeply increased in China but decreased in the other reporting countries. In tropical Africa, influenza activity increased in some countries of Western Africa, while detections were low across reporting countries in Middle and Eastern Africa. In Southern Asia, influenza activity remained low, with influenza A(H3N2) and B/Victoria lineage viruses predominant. In South-East Asia, influenza activity remained elevated, with influenza B mainly detected in Malaysia and A(H3N2) in Singapore and Thailand. In the temperate zones of the southern hemisphere, influenza activity remained low. SARS-CoV-2 positivity from sentinel surveillance remained around 20% globally. Activity remained at about 25% in the WHO Region of the Americas and around 15% in the Eastern Mediterranean region. Activity remained around 10% in the other regions. SARS-CoV-2 positivity from non-sentinel surveillance was reported at approximately 30% globally. Avian Influenza: A summary of the avian influenza situation in the region, case management and recommendations are available at Epidemiological alerts and updates | PAHO/WHO | Pan American Health Organization (paho.org)

[RESUMEN SEMANAL]. América del Norte: la actividad del virus de la influenza disminuyó en toda la subregión, con predominio de los virus influenza B. Se detectaron todos los subtipos de influenza estacional. El SARS-CoV-2 circula a niveles moderados, mientras que la actividad del VRS estuvo baja. La actividad de la influenza estuvo baja en Canadá y los Estados Unidos. En México, la actividad de la influenza ha aumentado recientemente a un nivel de baja intensidad, con una actividad de SARS-CoV-2 y del VRS elevada. Caribe: el porcentaje de positividad de la influenza estuvo moderado, debido principalmente por las detecciones de influenza B linaje Victoria. Además, circuló concurrentemente el virus influenza A(H1N1)pdm09. En Belice la actividad de la influenza aumentó con la circulación concurrente de influenza B linaje Victoria e influenza A(H1N1)pdm09. En general, la actividad del SARS-CoV-2 y del VRS estuvo baja en la subregión. América Central: la actividad de la influenza estuvo moderada, con predominio de influenza B/Victoria y circulación concurrente de los virus influenza A(H3N2) y A(H1N1)pdm09. En El Salvador, la actividad de la influenza estuvo elevada debido a los virus influenza B/Victoria y A(H3N2), y Guatemala reportó una mayor actividad con circulación de todos los subtipos estacionales. En Honduras, la actividad de la influenza se incrementó debido a los virus influenza B. El porcentaje de positividad del SARS-CoV-2 disminuyó en la subregión, excepto en Costa Rica. La actividad del VRS estuvo baja en general. Países Andinos: la actividad de la influenza estuvo baja, predominando los virus influenza A(H1N1)pdm09; con circulación concurrente de los virus influenza B/Victoria y A(H3N2). Bolivia reportó un aumento en la actividad de la influenza, con un número de casos de IRAG por cada 100 hospitalizaciones en niveles moderados y un 14 % positivos para influenza. En la subregión la actividad de SARS-CoV-2 y del VRS estuvo baja en general. Brasil y Cono Sur: la actividad de la influenza estuvo baja, con detección más frecuente de los virus influenza B. Se detectaron todos los subtipos de influenza estacional. Se reportó una mayor actividad de SARS-CoV-2 en Brasil, Chile y Paraguay, mientras que el VRS estuvo elevado en Brasil. Global: la actividad de la influenza disminuyó luego de un pico a fines de 2022, volviendo a aumentar entre fines de febrero y marzo con un aumento en la actividad del virus influenza B. Durante el período reportado, predominaron los virus influenza A, con una mayor proporción de virus A(H1N1)pdm09 en las muestras con subtipo determinado. En general en Europa las detecciones de influenza disminuyeron y la positividad de la influenza en los sitios centinela se mantuvo estable y por encima del umbral epidémico a nivel regional. De 37 países, 16 reportaron una intensidad media, y el resto reportó una intensidad baja o por debajo de la línea basal. Dieciocho de 36 países reportaron actividad generalizada. En general, los virus influenza B predominaron tanto en la vigilancia centinela como en la no centinela, ya que todas las subregiones experimentaron una ola de actividad de influenza B después de una ola inicial de influenza A. En Asia central la actividad de la influenza disminuyó. En el norte de África las detecciones de influenza estuvieron muy bajas en todos los países que reportaron. En algunos países de Asia occidental continuó el reporte de actividad de la influenza con detecciones de todos los subtipos de influenza estacional. En el este de Asia la actividad de la influenza, predominantemente A(H1N1)pdm09, aumentó considerablemente en China, pero disminuyó en los demás países que reportaron. En África tropical la actividad de la influenza aumentó en algunos países de África occidental, mientras que en los países que reportaron de África central y oriental las detecciones estuvieron bajas. En el sur de Asia la actividad de la influenza se mantuvo baja, con predominio de los virus influenza A(H3N2) y B/Victoria. En el sudeste asiático, la actividad de la influenza se mantuvo elevada, con detecciones de influenza B principalmente en Malasia y A(H3N2) en Singapur y Tailandia. En las zonas templadas del hemisferio sur la actividad de la influenza se mantuvo baja. A nivel mundial la positividad del SARS-CoV-2 en la vigilancia centinela se mantuvo alrededor del 20,0 %. La actividad se mantuvo en alrededor del 25,0 % en la Región de las Américas y aumentó al 15 % en el Mediterráneo oriental y en el Pacífico occidental. La actividad se mantuvo por debajo del 10,0 % en las demás regiones. La positividad de SARS-CoV-2 en la vigilancia no centinela estuvo alrededor del 30,0 %. Influenza Aviar: el resumen sobre la situación epidemiológica de influenza aviar en la región, manejo de los casos y recomendaciones se encuentran disponibles en Alertas y actualizaciones epidemiológicas | OPS/OMS | Organización Panamericana de la Salud (paho.org)

Weekly COVID-19 Epidemiological Update: Issue 60 (28 March 2023)

Since the onset of the pandemic in 2020 and up to 28 March 2023, a cumulative total of approximately 761 million COVID-19 cases including about 6.9 million deaths were reported from all six WHO regions. During the epidemiological week (EW) 12, cases and deaths decreased in all WHO regions except for the region of the Americas (cases; 5.1% & deaths; 11.3%). In the region of the Americas, 267,202 cases and 2,790 deaths were reported in EW 12 – a 5.1% increase in cases and 11.3% increase in deaths compared to the previous week. At the subregional level, COVID-19 cases increased in one subregion - North America (13%). Deaths increased in two subregions - North America (15.6%) and Caribbean and Atlantic Ocean Islands (11.1%). The overall weekly case notification rate for the region of the Americas was 26.1 cases per 100,000 population during EW 12 (24.8 the previous week). Between EW 12 and 11, the 14- day COVID-19 death rate was 5.2 deaths per 1 million population (4.8 the previous two weeks). Among 19 countries/territories in the region with available data, COVID-19 hospitalizations increased in 5 countries and territories (range: 29% - 100%) during EW 12 compared to the previous week. Among 15 countries and territories with available data, COVID-19 ICU admissions increased in 2 countries and territories (range: 20% - 100%).

Weekly COVID-19 Epidemiological Update: Issue 59 (21 March 2023)

In the region of the Americas, 191,466 cases and 2,150 deaths were reported in EW 11 – a -34.8% decrease in cases and -19.3% decrease in deaths compared to the previous week. The overall weekly case notification rate for the region of the Americas was 18.7 cases per 100,000 population during EW 11 (28.7 the previous week). Between EW 11 and 10, the 14-day COVID-19 death rate was 4.7 deaths per 1 million population (5.6 the previous two weeks). Among 17 countries/territories in the region with available data, COVID-19 hospitalizations increased in 4 countries and territories (range: 1.1% - 100%) during EW 11 compared to the previous week. Among 14 countries and territories with available data, COVID-19 ICU admissions increased in 7 countries and territories (range: 6.7% - 200%).

Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 11 (24 March 2023)

[WEEKLY SUMMARY]. North America: Influenza virus activity was low overall, with the predominance of influenza A viruses. The influenza A(H1N1)pdm09 virus predominated among subtyped samples, with co-circulation of A(H3N2) and B/Victoria. SARS-CoV-2 activity decreased; RSV activity was low. In Canada, all seasonal influenza subtypes circulated with low activity, influenza B virus predominated. In Mexico, influenza activity was low, with elevated SARS-CoV-2 and RSV activity. In the United States, influenza and RSV activity were low, while SARS-CoV-2 activity remained elevated. Pneumonia, influenza, and SARS-CoV-2 mortality was primarily associated with COVID-19. Caribbean: Influenza activity was moderate, with influenza B viruses more frequently detected. Influenza B/Victoria and A(H1N1)pdm09 co-circulated. Belize and Jamaica reported increased influenza activity. Overall, SARS-CoV-2 activity was low in the subregion, except in Dominica, where it was moderate. RSV activity was low. Central America: Influenza activity was moderate overall, with influenza B/Victoria virus predominance. Influenza A(H3N2) and A(H1N1)pdm09 co-circulated. Influenza activity was moderate in El Salvador, while Guatemala and Honduras reported low activity. SARS-CoV-2 percent positivity dropped in the subregion, except in Costa Rica. RSV activity was low overall. Andean: Influenza activity was low, predominating influenza A(H1N1)pdm09; influenza A(H3N2) and B/Victoria viruses co-circulated. Influenza activity remained elevated in Bolivia; SARI cases / 100 hospitalizations were moderate, and 14.5% tested positive for influenza. SARS-CoV-2 and RSV activity were low overall. Brazil and Southern Cone: Influenza activity was low; influenza B viruses were detected more frequently, with B/Victoria, A(H1N1)pdm09, and A(H3N2) co-circulation. In addition, increased SARS-CoV-2 activity was reported in Brazil, Chile, and Paraguay, while RSV was elevated in Brazil. Avian Influenza: A summary of the avian influenza situation in the region, case management and recommendations are available at Epidemiological alerts and updates | PAHO/WHO | Pan American Health Organization (paho.org)

[RESUMEN SEMANAL]. América del Norte: la actividad del virus de la influenza estuvo baja en general, con predominio de los virus influenza A. El virus influenza A(H1N1)pdm09 predominó entre las muestras con subtipo determinado, con circulación concurrente de A(H3N2) y B/Victoria. La actividad del SARS-CoV-2 disminuyó; la actividad del VRS estuvo baja. En Canadá, todos los subtipos de influenza estacional circularon con baja actividad, predominando el virus influenza B. En México, la actividad de la influenza estuvo baja, con actividad elevada de SARS-CoV-2 y del VRS. En los Estados Unidos, la actividad de la influenza y del VRS estuvo baja, mientras que la actividad del SARS-CoV-2 permaneció elevada. La mortalidad por neumonía, influenza y SARS-CoV-2 estuvo asociada principalmente con la COVID-19. Caribe: la actividad de la influenza estuvo moderada, los virus de la influenza B se detectaron con mayor frecuencia. Influenza B/Victoria y A(H1N1)pdm09 circularon concurrentemente. Belice y Jamaica reportaron un aumento de la actividad de la influenza. En general, la actividad del SARS-CoV-2 estuvo baja en la subregión, excepto en Dominica, donde estuvo moderada. La actividad del VRS estuvo baja. América Central: la actividad de la influenza estuvo moderada en general, con predominio del virus influenza B/Victoria. Circularon concurrentemente influenza A(H3N2) y A(H1N1)pdm09. La actividad de influenza estuvo moderada en El Salvador, mientras que Guatemala y Honduras reportaron baja actividad. El porcentaje de positividad de SARS-CoV-2 disminuyó en la subregión, excepto en Costa Rica. La actividad del VRS estuvo baja. Países Andinos: la actividad de la influenza estuvo baja, con predominio de influenza A(H1N1)pdm09; circularon concurrentemente los virus influenza A(H3N2) y B/Victoria. La actividad de la influenza se mantuvo elevada en Bolivia; el número de casos de IRAG por cada 100 hospitalizaciones fueron moderados y el 14,5 % resultaron positivos para influenza. La actividad del SARS CoV-2 y del VRS estuvo baja en general. Brasil y Cono Sur: la actividad de la influenza estuvo baja; los virus influenza B se detectaron con mayor frecuencia, con circulación concurrente de influenza B/Victoria, A(H1N1)pdm09 y A(H3N2). Además, se reportó una mayor actividad de SARS-CoV-2 en Brasil, Chile y Paraguay, mientras que la actividad del VRS estuvo elevada en Brasil. Influenza Aviar: el resumen sobre la situación epidemiológica de influenza aviar en la región, manejo de los casos y recomendaciones se encuentran disponibles en Alertas y actualizaciones epidemiológicas | OPS/OMS | Organización Panamericana de la Salud (paho.org)

Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 10 (17 March 2023)

[WEEKLY SUMMARY]. North America: Influenza virus activity decreased throughout the sub-region, with the predominance of influenza A(H1N1)pdm09. Influenza A(H3N2)pdm09 and B/Victoria co-circulated. SARS-CoV-2 circulates at moderate levels, while RSV activity remains low. In Canada, influenza activity was low, with influenza B virus predominance. In Mexico, influenza activity was low, with elevated SARS-CoV-2 and RSV activity. In the United States, influenza and RSV activity were low, while SARS-CoV-2 activity remained elevated. Caribbean: Influenza activity decreased, with influenza A and B viruses equally detected. Influenza A(H1N1)pdm09 and B/Victoria co-circulated. Belize reported increased influenza activity. Overall, SARS-CoV-2 activity was low in the subregion, except in Dominica and Jamaica, where it was moderate. RSV was moderate in Jamaica; elsewhere in the subregion, RSV activity was low. Central America: Influenza activity was moderate overall, with influenza B/Victoria virus predominance. Influenza A(H3N2) and A(H1N1)pdm09 co-circulated. Honduras reported increased influenza activity, while Guatemala and Panama had moderate activity. SARS-CoV-2 percent positivity dropped in the subregion, except in Costa Rica. RSV activity was low overall. Andean: Influenza activity was low, predominating influenza B/Victoria viruses; influenza A(H1N1)pdm09 and A(H3N2) viruses co-circulated. Bolivia, Ecuador, and Venezuela reported increased influenza activity. In Bolivia, SARI cases / 100 hospitalizations were moderate, and 14% tested positive for influenza. SARS-CoV-2 and RSV activity were low overall. Brazil and Southern Cone: Influenza activity was at interseason levels; influenza B viruses were detected more frequently, with B/Victoria and A(H1N1)pdm09 co-circulation. Increased SARS-CoV-2 activity was reported in Brazil and Chile, while RSV was elevated in Brazil. Global: Influenza activity continued to decrease following the peak in late 2022. Influenza A viruses predominated, with a slightly larger proportion of A(H1N1)pdm09 viruses detected among the subtyped influenza A viruses. The proportion of influenza B virus detections increased recently. In Europe, overall influenza detections decreased slightly, and influenza positivity from sentinel sites decreased, although remaining above the epidemic threshold at the regional level. Out of 39 countries, 17 reported high or moderate intensity, and over half continued to report widespread activity. Overall, influenza B viruses were predominated in both sentinel, and non-sentinel surveillance as all subregions experienced a wave of influenza B activity after an initial influenza A wave. Influenza detections decreased or were stable in most countries except Belarus, Croatia, Hungary, Luxembourg, and Montenegro, where increases were reported. In Central Asia, influenza activity decreased overall. In Northern Africa, detections of influenza A and B viruses continued to decline in Morocco and Tunisia. In Western Asia, influenza activity continued to be reported in some countries with detections of all seasonal influenza subtypes. In East Asia, influenza activity of predominantly A(H1N1)pdm09 steeply increased in China but decreased in the other reporting countries. In tropical Africa, influenza activity increased in some countries of Western Africa, while detections were low across reporting countries in Middle and Eastern Africa. In Southern Asia, influenza activity remained low, with influenza A(H3N2) and B/Victoria lineage viruses mainly detected. In South-East Asia, influenza activity remained elevated, with influenza B mainly detected in Malaysia and A(H3N2) in Singapore and Thailand. In the temperate zones of the Southern Hemisphere, influenza activity remained at the inter-seasonal level. RSV activity was generally low or decreasing globally, except in South Africa, where activity remained high. SARS-CoV-2 positivity from sentinel surveillance remained around 20% globally. Activity remained at about 25% in the WHO Region of the Americas and increased to 15% in the Eastern Mediterranean and Western Pacific Regions. Activity remained below 10% in the other regions. SARS-CoV-2 positivity from non-sentinel surveillance was reported at around 30% globally. Avian Influenza: A summary of the avian influenza situation in the region, case management and recommendations are available at Epidemiological alerts and updates | PAHO/WHO | Pan American Health Organization (paho.org)

[RESUMEN SEMANAL]. América del Norte: la actividad del virus de influenza disminuyó en toda la subregión, con predominio de influenza A(H1N1)pdm09. Circularon concurrentemente los virus influenza A(H3N2)pdm09 y B/Victoria. El SARS-CoV-2 circula a niveles moderados, mientras que la actividad de VRS permanece baja. En Canadá, la actividad de la influenza estuvo baja, con predominio del virus influenza B. En México, la actividad de la influenza estuvo baja, con actividad elevada de SARS-CoV‑2 y del VRS. En los Estados Unidos, la actividad de la influenza y del VRS estuvo baja, mientras que la actividad del SARS-CoV-2 permaneció elevada. Caribe: la actividad de la influenza disminuyó, con la detección en iguales proporciones de los virus influenza A y B. Circularon concurrentemente los virus influenza A(H1N1)pdm09 y B/Victoria. Belice notificó un aumento de la actividad de la influenza. En general, la actividad del SARS-CoV-2 estuvo baja en la subregión, excepto en Dominica y Jamaica, donde estuvo moderada. La actividad del VRS estuvo moderada en Jamaica; en otras partes de la subregión, la actividad del VRS estuvo baja. América Central: la actividad de la influenza estuvo moderada en general, con predominio del virus influenza B/Victoria. Circularon concurrentemente los virus influenza A(H3N2) y A(H1N1)pdm09. Honduras reportó una mayor actividad de influenza, mientras que Guatemala y Panamá tuvieron una actividad moderada. El porcentaje de positividad de SARS-CoV-2 disminuyó en la subregión, excepto en Costa Rica. La actividad del VRS estuvo baja en general. Países Andinos: la actividad de la influenza estuvo baja, predominando los virus influenza B/Victoria; circularon concurrentemente los virus influenza A(H1N1)pdm09 y A(H3N2). Bolivia, Ecuador y Venezuela reportaron un aumento de la actividad de la influenza. En Bolivia, el número de casos de IRAG por cada 100 hospitalizaciones estuvo en niveles moderados y el 14% resultaron positivos para influenza. La actividad del SARS-CoV-2 y del VRS estuvo en general baja. Brasil y Cono Sur: la actividad de la influenza estuvo en niveles entre temporadas; los virus influenza B fueron detectados más frecuentemente, con circulación concurrente de B/Victoria y A(H1N1)pdm09. Se informó una mayor actividad de SARS-CoV-2 en Brasil y Chile, mientras que la actividad del VRS estuvo elevada en Brasil. Global: la actividad de la influenza continuó disminuyendo luego del pico a fines de 2022. Predominaron los virus influenza A con una proporción ligeramente mayor de A(H1N1)pdm09 entre las muestras con subtipo determinado. La proporción de detecciones del virus influenza B aumentó en las últimas semanas. En Europa las detecciones de influenza disminuyeron ligeramente y en los sitios centinela la positividad de la influenza disminuyó, aunque se mantuvo por encima del umbral epidémico a nivel regional. De 39 países, 17 reportaron una intensidad alta o moderada y más de la mitad continuaron reportando una actividad generalizada. En general, los virus influenza B predominaron tanto en la vigilancia centinela como en la no centinela, ya que todas las subregiones experimentaron una ola de actividad de influenza B después de una ola inicial de influenza A. Las detecciones de influenza disminuyeron o se mantuvieron estables en la mayoría de los países, excepto Bielorrusia, Croacia, Hungría, Luxemburgo y Montenegro, en donde se reportó un aumento. En Asia central, la actividad de la influenza disminuyó en general. En el norte de África las detecciones de virus de influenza A y B continuaron disminuyendo en Marruecos y Túnez. En Asia occidental continuó el reporte de actividad de la influenza en algunos países con la detección de todos los subtipos de influenza estacional. En el este de Asia, la actividad de la influenza predominantemente A(H1N1)pdm09 aumentó considerablemente en China, pero disminuyó en los demás países que reportaron. En África tropical, la actividad de la influenza aumentó en algunos países de África occidental, mientras que las detecciones estuvieron bajas en los países de África central y oriental que notificaron. En el sur de Asia, la actividad de la influenza se mantuvo baja y se detectaron principalmente virus influenza A(H3N2) y B/Victoria. En el sudeste asiático, la actividad de la influenza se mantuvo elevada, con detecciones de influenza B principalmente en Malasia y A(H3N2) en Singapur y Tailandia. En las zonas templadas del hemisferio sur la actividad de la influenza se mantuvo en los niveles entre estaciones. La actividad del VRS estuvo baja o disminuyó a nivel mundial, excepto en Sudáfrica en donde la actividad se mantuvo alta. A nivel mundial la positividad de SARS-CoV-2 en la vigilancia centinela se mantuvo alrededor del 20%. La actividad se mantuvo en alrededor del 25 % en la Región de las Américas y aumentó al 15 % en las Regiones del Mediterráneo Oriental y del Pacífico Occidental. La actividad se mantuvo por debajo del 10% en las demás regiones. La positividad de SARS-CoV-2 en la vigilancia no centinela estuvo alrededor del 30% a nivel mundial. Influenza Aviar: el resumen sobre la situación epidemiológica de influenza aviar en la región, manejo de los casos y recomendaciones se encuentran disponibles en Alertas y actualizaciones epidemiológicas | OPS/OMS | Organización Panamericana de la Salud (paho.org)

Weekly COVID-19 Epidemiological Update: Issue 58 (14 March 2023) 

Since the onset of the pandemic in 2020 and up to 14 March 2023, a cumulative total of 759.6 million COVID-19 cases including 6.9 million deaths were reported from all six WHO regions. During epidemiological week (EW) 10, both cases and deaths decreased in all regions. In the region of the Americas, 239,498 cases and 2,346 deaths were reported in EW 10 – a -30.3% decrease in cases and -22.9% decrease in deaths compared to the previous week. At the subregional level, COVID-19 cases and deaths decreased in all subregions. The overall weekly case notification rate for the region of the Americas was 23.4 cases per 100,000 population during EW 10 (33.3 the previous week). Between EW 10 and 9, the 14- day COVID-19 death rate was 5.3 deaths per 1 million population (6.7 the previous two weeks). Among 16 countries and territories in the region with available data, COVID-19 hospitalizations increased in 8 countries and territories (range: 1.5% - 100%) during EW 10 compared to the previous week. Among 14 countries and territories with available data, COVID-19 ICU admissions increased in 6 countries and territories (range: 0.3% - 100%).

Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 9 (10 March 2023)

[WEEKLY SUMMARY]. North America: Influenza virus activity decreased throughout the sub-region, with the predominance of influenza A(H3N2)pdm09. Influenza A(H1N1)pdm09 and B/Victoria co-circulated. SARS-CoV-2 circulates at moderate levels, and RSV activity was low. In Canada, influenza activity was low, with influenza B virus predominance. In Mexico, influenza activity decreased, while SARS-CoV-2 and RSV activity remained elevated. In the United States, influenza and RSV activity were low, while SARS-CoV-2 activity remained moderate. Caribbean: Influenza activity remains increased, although showing a decreasing trend, with A(H1N1)pdm09 predominance and A(H3N2) and B/Victoria co-circulation. Belize and Haiti reported increased influenza activity, with influenza A(H1N1)pdm09 predominance. Likewise, Guadeloupe, Martinique, and Saint-Martin reported increased influenza activity in the French Territories. SARS-CoV-2 activity was low in the subregion, except in Jamaica and Suriname, where it was raised. Jamaica reported increased RSV activity; elsewhere in the subregion, RSV activity was low. Central America: Influenza activity was moderate, with influenza B/Victoria virus predominance. Influenza A(H3N2) and A(H1N1)pdm09 co-circulated. Guatemala, Honduras, and Panama reported increased influenza activity. SARS-CoV-2 percent positivity decreased in the subregion, except in Costa Rica. RSV activity was low overall. Andean: Influenza activity was low, predominating influenza A(H1N1)pdm09 viruses; influenza B/Victoria and A(H3N2) viruses co‑circulated. Bolivia, Ecuador, and Venezuela reported increased influenza activity. In Bolivia, SARI cases / 100 hospitalizations were at moderate levels, and 22% tested positive for influenza. SARS‑CoV-2 and RSV activity were low overall. Brazil and Southern Cone: Influenza activity was at interseason levels; influenza B/Victoria viruses were detected more frequently with A(H1N1)pdm09 co-circulation. Paraguay reported increased influenza B (lineage not performed) activity at low-intensity levels. SARS-CoV-2 activity was low overall, but Brazil and Chile reported increased activity. RSV activity was low in the subregion, except in Brazil, where high levels were registered. Avian Influenza: A summary of the avian influenza situation in the region, case management and recommendations are available at Epidemiological alerts and updates | PAHO/WHO | Pan American Health Organization (paho.org)

[RESUMEN SEMANAL]. América del Norte: la actividad del virus de la influenza disminuyó en toda la subregión, con predominio de influenza A(H3N2)pdm09. Circularon concurrentemente los virus influenza A(H1N1)pdm09 y B/Victoria. El SARS-CoV-2 circuló en niveles moderados y la actividad del VRS estuvo baja. En Canadá, la actividad de la influenza estuvo baja, con predominio del virus influenza B. En México, la actividad de la influenza disminuyó, mientras que la del SARS-CoV‑2 y del VRS permaneció elevada. En los Estados Unidos, la actividad de la influenza y del VRS estuvo baja, mientras que la del SARS-CoV-2 se mantuvo moderada. Caribe: la actividad de la influenza permaneció aumentada, aunque muestra una tendencia decreciente, con predominio de A(H1N1)pdm09 y circulación concurrente de A(H3N2) y B/Victoria. Belice y Haití reportaron un aumento de la actividad de la influenza, con predominio de influenza A(H1N1)pdm09. Asimismo, Guadalupe, Martinica y San Martín notificaron un aumento de la actividad de la influenza en los territorios franceses. La actividad del SARS-CoV-2 estuvo baja en la subregión, excepto en Jamaica y Surinam, donde se elevó. Jamaica notificó un aumento de la actividad del VRS; en el resto de la subregión, la actividad del VRS estuvo baja. América Central: la actividad de la influenza estuvo moderada, con predominio de influenza B/Victoria. Circularon concurrentemente los virus influenza A(H3N2) y A(H1N1)pdm09. Guatemala, Honduras y Panamá reportaron un aumento de la actividad de la influenza. El porcentaje de positividad de SARS-CoV-2 disminuyó en la subregión, excepto en Costa Rica. La actividad del VRS estuvo baja en general. Países Andinos: la actividad de influenza estuvo baja, con predominio de los virus influenza A(H1N1)pdm09; circularon concurrentemente los virus influenza B/Victoria y A(H3N2). Bolivia, Ecuador y Venezuela reportaron un aumento de la actividad de la influenza. En Bolivia el número de casos de IRAG por cada 100 hospitalizaciones estuvo en niveles moderados, y el 22% resultaron positivos para influenza. La actividad de SARS-CoV-2 y del VRS estuvo baja en general. Brasil y Cono Sur: la actividad de la influenza estuvo en niveles entre temporadas; los virus influenza B/Victoria se detectaron con mayor frecuencia con la circulación concurrente de A(H1N1)pdm09. Paraguay notificó un aumento de la actividad de la influenza B (linaje indeterminado) a niveles de baja intensidad. La actividad del SARS-CoV-2 estuvo baja en general, pero Brasil y Chile reportaron una mayor actividad. La actividad del VRS estuvo baja en la subregión, excepto en Brasil, donde se registraron niveles altos. Influenza Aviar: el resumen sobre la situación epidemiológica de influenza aviar en la región, manejo de los casos y recomendaciones se encuentran disponibles en Alertas y actualizaciones epidemiológicas | OPS/OMS | Organización Panamericana de la Salud (paho.org)