Detection of dengue virus serotype 4 in Panama after 23 years without circulation.

Panama is a country with endemic Dengue virus (DENV) transmission since its reintroduction in 1993. The four serotypes have circulated in the country and the region of the Americas, however, DENV-4 confirmed autochthonous cases have not been identified since 2000, despite its circulation in neighboring countries. Here, we report DENV-4 detection in Panama in the last four-month period of 2023 with co-circulation of the other serotypes, this was associated with a peak of dengue cases during the dry season even though most dengue outbreaks are described in the rainy season. Complete genomes of DENV-4 allowed us to determine that cases were caused by DENV-4 genotype IIb, the same genotype as 23 years ago, with high similarity to DENV-4 sequences circulating in Nicaragua and El Salvador during 2023. This report shows the importance of maintaining serotype and genotype surveillance for early detection of new variants circulating in the country.

Brote de Zika en Panamá. Caracterización del primer brote epidémico del virus Zika registrado en Panamá

Introducción: La caracterización de los brotes de Zika es de gran importancia para lograr determinar los factores de riesgos individuales y colectivos que participan en su ocurrencia y es la base para el desarrollo de estrategias efectivas para la vigilancia, prevención y control de la transmisión de esta enfermedad. Objetivo: Describir epidemiológicamente las principales características del primer brote epidémico de Zika registrado en Panamá, en la Comarca de Guna Yala. Materiales y métodos: Se diseño y realizó un estudio descriptivo y retrospectivo del primer brote de Zika ocurrido entre el 27 de noviembre de 2015 y el 22 de enero de 2016 en Guna Yala, Panamá. Resultados: Se colectaron un total de 68 muestras de suero de pacientes sospechosos, 38 muestras fueron positivas por PCR para Zika en la Comarca de Guna Yala, Ustupo registró la mayor cantidad de casos (n = 29, 76,3%), el (n = 43; 86%) de los casos fueron menores de 59 años, el (n = 37; 74%) de los casos eran población económicamente activa (14 a 65 años de edad) y el (n = 30; 60%) de los casos fueron de sexo femenino. Conclusión: Este estudio ha permitido mostrar la facilidad con que las enfermedades arbovirales como el Zika puede introducirse, propagarse y llegar a producir un impacto en la salud pública de la población, el sistema de salud y establecerse en las regiones donde ocurren estos eventos sanitarios. Es necesario realizar más estudios, el fortalecimiento de la vigilancia epidemiológica y la consideración de los factores de riesgo para garantizar la sostenibilidad de las intervenciones sanitarias y lograr reducir el impacto social y económico de este arbovirosis. (provisto por Infomedic International)

Introduction: The characterization of Zika outbreaks is of great importance to determine the individual and collective risk factors involved in their occurrence and is the basis for the development of effective strategies for surveillance, prevention and control of Zika transmission. Objective: To describe epidemiologically the main characteristics of the first epidemic outbreak of Zika recorded in Panama, in the Guna Yala region.  Materials and methods: A descriptive and retrospective study of the first Zika outbreak that occurred between 27 November 2015 and 22 January 2016 in Guna Yala, Panama, was designed and conducted.  Results: A total of 68 serum samples were collected from suspected patients, 38 samples were positive by PCR for Zika in the Guna Yala Comarca, Ustupo registered the highest number of cases (n = 29, 76.3%), (n = 43; 86%) of the cases were younger than 59 years, (n = 37; 74%) of the cases were economically active population (14 to 65 years of age) and (n = 30; 60%) of the cases were female. Conclusion: This study has shown the ease with which arboviral diseases such as Zika can be introduced, spread and have an impact on the public health of the population, the health system and become established in the regions where these health events occur. Further studies strengthened epidemiological surveillance and consideration of risk factors are needed to ensure the sustainability of health interventions and to reduce the social and economic impact of this arbovirosis. (provided by Infomedic International)

Early Transmission Dynamics, Spread, and Genomic Characterization of SARS-CoV-2 in Panama.

We report an epidemiologic analysis of 4,210 cases of infection with severe acute respiratory syndrome coronavirus 2 and genetic analysis of 313 new near-complete virus genomes in Panama during March 9-April 16, 2020. Although containment measures reduced R0 and Rt, they did not interrupt virus spread in the country.

Epidemiología del dengue en Centroamérica y República Dominicana / Epidemiology of dengue in Central America and the Dominican Republic

Resumen Introducción: Centroamérica experimenta una alta carga de la enfermedad por dengue aportando cerca de 8% de todos los casos del continente. Este trabajo reporta la epidemiología del dengue en la subregión en un período de 10 años. Objetivos: Documentar la epidemiología del dengue en Centro América y República Dominicana. Material y Métodos: Período de estudio: años 2005-2014. Se recopilaron y analizaron los datos de casos y muertes por dengue de los países de Centro América y República Dominicana, reportados por los Ministerios de Salud y se corroboró con los datos publicados en los boletines en línea y la base de datos interactiva de la Organización Panamericana de la Salud (OPS). Se obtuvieron estadísticas poblacionales de los Institutos Nacionales de Estadística y Censo de cada país. Resultados: Durante el período de estudio fueron notificados 1.118.464 casos de dengue. Reportados 32.431 casos graves, 888 personas fallecidas. La letalidad por caso de dengue fue en promedio 0,08%. Los cuatro serotipos de dengue circularon durante el decenio estudiado. Discusión: La información clínica y epidemiológica, indica tasas de incidencia alta, que han fluctuado en los últimos años, con co-circulación significativa de varios serotipos a la vez. Conclusiones: Se identificaron diferencias notorias en la recolección de datos de la vigilancia entre países. Se determinó un patrón epidemiológico heterogéneo.

Background: Central America experiences a high burden of dengue reporting about 8% of all cases in the continent. This work reports the epidemiology of dengue in the sub region in a 10 years period. Aim: To describe the epidemiology of dengue in Central America and the Dominican Republic. Methods: Study period from 2005 to 2014. The data on dengue cases and deaths of the countries of Central America and the Dominican Republic, reported by the Ministries of Health, were compiled and analyzed and corroborated with the data published in the online bulletins and the interactive database of the Pan American Health Organization (PAHO). Population statistics were obtained from the National Statistics and Census Institutes of each country. Results: During the study period, 1,118,464 cases of dengue were notified. There were 32,431 serious cases reported, 888 people died. The lethality per case of dengue was on average 0.08%. The four dengue serotypes circulated during the decade analyzed. Discussion: Clinical and epidemiological information indicates high incidence rates, which have fluctuated in recent years, with significant co-circulation of several serotypes at the same time. Conclusions: Notorious surveillance data collection differences were identified between countries, determining a heterologous epidemiological pattern.

Molecular Epidemiology of Dengue in Panama: 25 Years of Circulation.

Dengue virus (DENV) is the most prevalent arbovirus in terms of human public health importance globally. In addition to DENV epidemiological surveillance, genomic surveillance may help investigators understand the epidemiological dynamics, geographic distribution, and temporal patterns of DENV circulation. Herein, we aimed to reconstruct the molecular epidemiology and phylogeny of DENV in Panama to connect the epidemiological history of DENV dispersal and circulation in Latin America. We retrospectively analyzed the epidemiological data obtained during 25 years of DENV surveillance in Panama. DENV was reintroduced in Panama in 1993 after a 35 year absence of autochthonous transmission. The increase in the number of total dengue cases has been accompanied by an increase in severe and fatal cases, with the highest case fatality rate recorded in 2011. All four serotypes were detected in Panama, which is characterized by serotype replacement and/or co-circulation of multiple serotypes. Phylogenetic analysis of datasets collected from envelope (E) gene sequences obtained from viruses isolated from human sera demonstrated that circulating viruses were highly diverse and clustered in distinct clades, with co-circulation of clades from the same genotype. Our analyses also suggest that Panamanian strains were related to viruses from different regions of the Americas, suggesting a continuous exchange of viruses within the Americas.

The decline of dengue in the Americas in 2017: discussion of multiple hypotheses.

OBJECTIVE: Since the 1980s, dengue incidence has increased 30-fold. However, in 2017, there was a noticeable reduction in reported dengue incidence cases within the Americas, including severe and fatal cases. Understanding the mechanism underlying dengue's incidence and decline in the Americas is vital for public health planning. We aimed to provide plausible explanations for the decline in 2017. METHODS: An expert panel of representatives from scientific and academic institutions, Ministry of Health officials from Latin America and PAHO/WHO staff met in October 2017 to propose hypotheses. The meeting employed six moderated plenary discussions in which participants reviewed epidemiological evidence, suggested explanatory hypotheses, offered their expert opinions on each and developed a consensus. RESULTS: The expert group established that in 2017, there was a generalised decreased incidence, severity and number of deaths due to dengue in the Americas, accompanied by a reduction in reported cases of both Zika and chikungunya virus infections, with no change in distribution among age groups affected. This decline was determined to be unlikely due to changes in epidemiological surveillance systems, as similar designs of surveillance systems exist across the region. Although sudden surveillance disruption is possible at a country or regional level, it is unlikely to occur in all countries simultaneously. Retrospective modelling with epidemiological, immunological and entomological information is needed. Host or immunological factors may have influenced the decline in dengue cases at the population level through immunity; however, herd protection requires additional evidence. Uncertainty remains regarding the effect on the outcome of sequential infections of different dengue virus (DENV) types and Zika virus (ZIKV), and vice versa. Future studies were recommended that examine the epidemiological effect of prior DENV infection on Zika incidence and severity, the epidemiological effect of prior Zika virus infection on dengue incidence and severity, immune correlates based on new-generation ELISA assays, and impact of prior DENV/other arbovirus infection on ZIKV immune response in relation to number of infections and the duration of antibodies in relation to interval of protection. Follow-up studies should also investigate whether increased vector control intensification activities contributed to the decline in transmission of one or more of these arboviruses. Additionally, proposed studies should focus on the potential role of vector competence when simultaneously exposed to various arboviruses, and on entomological surveillance and its impact on circulating vector species, with a goal of applying specific measures that mitigate seasonal occurrence or outbreaks. CONCLUSIONS: Multifactorial events may have accounted for the decline in dengue seen in 2017. Differing elements might explain the reduction in dengue including elements of immunity, increased vector control, and even vector and\or viruses changes or adaptations. Most of the results of this expert consensus group meeting are hypothetical and based on limited evidence. Further studies are needed.

OBJECTIF: Depuis les années 1980, l'incidence de la dengue a été multipliée par 30. Cependant, en 2017, il y a eu une réduction notable du nombre de cas d'incidence de dengue rapportés dans les Amériques. Nous voulions fournir des explications plausibles à la baisse en 2017. MÉTHODES: Un groupe d'experts constitué de représentants d'institutions scientifiques et académiques, d'officiels des Ministères de la Santé d'Amérique Latine et de membres du personnel de l'OPS/OMS s'est réuni en octobre 2017 pour proposer et évaluer des hypothèses. RÉSULTATS: En 2017, il y a eu une baisse généralisée de l'incidence, de la sévérité et du nombre de décès dus à la dengue dans les Amériques, accompagnée d'une réduction des cas rapportés d'infections par le virus Zika et par le virus du chikungunya, sans modification dans la répartition entre les groupes d'âge affectés. Il a été déterminé que ce déclin était peu probablement dû aux changements dans les systèmes de surveillance épidémiologique, étant donné que des systèmes de surveillance similaires existaient dans toute la région. Bien que des perturbations soudaines dans la surveillance soient possibles au niveau national ou régional, il est peu probable que cela se produise simultanément dans tous les pays. Une modélisation rétrospective avec des informations épidémiologiques, immunologiques et entomologiques est nécessaire. Des facteurs liés à l'hôte ou immunologiques peuvent avoir influencé le déclin des cas de dengue au niveau de la population par le biais de l'immunité; cependant, l'évidence d'une protection conférée par l'effet du troupeau nécessite des données supplémentaires. Une incertitude subsiste quant à l'effet sur le résultat des infections séquentielles de différents types du virus de la dengue (DENV) et du virus Zika (ZIKV), et vice-versa. Les études à venir devraient examiner (1) l'effet épidémiologique d'une infection antérieure par le DENV sur l'incidence et la sévérité du virus Zika, (2) l'effet épidémiologique d'une infection antérieure par le virus Zika sur l'incidence et la sévérité de la dengue, (3) les corrélats immunitaires basés sur des tests ELISA de nouvelle génération, (4) l' impact d'une infection antérieure à DENV/autres arbovirus sur la réponse immunitaire au ZIKV en fonction du nombre d'infections et de la durée des anticorps en fonction de l'intervalle de protection, (5) si des activités d'intensification de la lutte antivectorielle ont contribué à la diminution de la transmission d'un ou plusieurs de ces arbovirus, (6) le rôle potentiel de la compétence vectorielle lorsqu'ils sont exposés simultanément à différents arbovirus, (7) la surveillance entomologique et son impact sur la circulation d'espèces de vecteurs, dans le but d'appliquer des mesures spécifiques qui réduisent l'occurrence saisonnière d'épidémies. CONCLUSIONS: Des événements multifactoriels pourraient expliquer le déclin observé de la dengue en 2017. La plupart des résultats de cette réunion du groupe de consensus d'experts sont hypothétiques, reposent sur des données limitées et requièrent des investigations supplémentaires.

[Epidemiology of dengue in Central America and the Dominican Republic]. / Epidemiología del dengue en Centroamérica y República Dominicana.

BACKGROUND: Central America experiences a high burden of dengue reporting about 8% of all cases in the continent. This work reports the epidemiology of dengue in the sub region in a 10 years period. AIM: To describe the epidemiology of dengue in Central America and the Dominican Republic. METHODS: Study period from 2005 to 2014. The data on dengue cases and deaths of the countries of Central America and the Dominican Republic, reported by the Ministries of Health, were compiled and analyzed and corroborated with the data published in the online bulletins and the interactive database of the Pan American Health Organization (PAHO). Population statistics were obtained from the National Statistics and Census Institutes of each country. RESULTS: During the study period, 1,118,464 cases of dengue were notified. There were 32,431 serious cases reported, 888 people died. The lethality per case of dengue was on average 0.08%. The four dengue serotypes circulated during the decade analyzed. DISCUSSION: Clinical and epidemiological information indicates high incidence rates, which have fluctuated in recent years, with significant co-circulation of several serotypes at the same time. CONCLUSIONS: Notorious surveillance data collection differences were identified between countries, determining a heterologous epidemiological pattern.

The reintroduction of DENV-2 in 2011 in Panama and subsequent outbreak characteristic.

The circulation of the South-east Asian/American (AS/AM) dengue 2 virus (DENV-2) genotype in the Americas has been associated with a high rate of severe disease. From 1993, the year DENV was reintroduced in Panama, until 2011 there were 29 dengue-associated deaths, 17 of which occurred in 2011, the most severe outbreak with a case fatality rate (CFR) of 44% (17 deaths out of 38 severe dengue cases). During this outbreak DENV-2 was reintroduced into the country, whereas over the prior five years DENV-1 and -3 were predominant. Herein, we describe the 2011 Panama outbreak and genetically characterize the Panamanian DENV-2 strains, which were associated with severe dengue disease in Panama. Our results suggest that the DENV-2 isolates from this outbreak belonged to the AS/AM genotype sub-clade 2BI and were genetically close to viruses described in the outbreaks in Nicaragua, Honduras, Guatemala and Mexico from 2006-2011. Sub-clade 2BI has previously been associated with severe disease in Nicaragua during outbreaks from 2005-2007.

Unusual pattern of chikungunya virus epidemic in the Americas, the Panamanian experience.

BACKGROUND: Chikungunya virus (CHIKV) typically causes explosive epidemics of fever, rash and polyarthralgia after its introduction into naïve populations. Since its introduction in Panama in May of 2014, few autochthonous cases have been reported; most of them were found within limited outbreaks in Panama City in 2014 and Puerto Obaldia town, near the Caribbean border with Colombia in 2015. In order to confirm that Panama had few CHIKV cases compared with neighboring countries, we perform an epidemiological analysis of chikungunya cases reported from May 2014 to July 2015. Moreover, to understand this paucity of confirmed CHIKV cases, a vectorial analysis in the counties where these cases were reported was performed. METHODS: Chikungunya cases were identified at medical centers and notified to health authorities. Sera samples were analyzed at Gorgas Memorial Institute for viral RNA and CHIKV-specific antibody detection. RESULTS: A total of 413 suspected cases of CHIKV infections were reported, with incidence rates of 0.5 and 0.7 per 100,000 inhabitants in 2014 and 2015, respectively. During this period, 38.6% of CHIKV cases were autochthonous with rash and polyarthralgia as predominant symptoms. CHIKV and DENV incidence ratios were 1:306 and 1:34, respectively. A phylogenetic analysis of E1/E2 genomic segment indicates that the outbreak strains belong to the Asian genotype and cluster together with CHIKV isolates from other American countries during the same period. Statistical analysis of the National Vector Control program at the district level shows low and medium vector infestation level for most of the counties with CHIKV cases. This index was lower than for neighboring countries. CONCLUSIONS: Previous training of clinical, laboratory and vector workers allowed a good caption and detection of the chikungunya cases and fast intervention. It is possible that low/medium vector infestation level could explain in part the paucity of chikungunya infections in Panama.

Macroecological patterns of American Cutaneous Leishmaniasis transmission across the health areas of Panamá (1980-2012).

American Cutaneous Leishmaniasis (ACL) is a neglected vector-borne zoonosis that persists despite increasing socio-economic development and urbanization in Panamá. Here, we investigate the association between environmental changes and spatio-temporal ACL transmission in the Republic of Panamá (1980-2012). We employ a macroecological approach, where patterns of variation in ACL incidence at the spatially coarse-grained scale of health areas are studied considering factors linked to the ecology of ACL transmission. We specifically study impacts of climatic variability, measured by the different phases of El Niño Southern Oscillation (ENSO), within diverse ecosystems and sand fly (Diptera: Psychodidae) vector species, as well as heterogeneous local climatic patterns, deforestation, population growth rates, and changes in social marginalization. We found that over the study period, patterns of ACL incidence: (i) were asynchronous with clusters changing from east to west of the Panamá Canal, (ii) trends increased in the west, and decreased or remained nearly constant in the east, independent of human population growth, (iii) generally increased in years following El Niño, and (iv) decreased as forest cover increased. We found no significant association between changes in socio-economic indicators and ACL transmission. Regarding vector abundance and presence, we found that studies had been biased to locations east of the Panamá canal, and that, in general, the abundance of dominant vector species decreased during the cold phase of ENSO. Finally, our results indicate that a macroecological approach is useful to understand heterogeneities related to environmental change impacts on ACL transmission.

Chikungunya virus infection: first detection of imported and autochthonous cases in Panama.

Chikungunya virus (CHIKV) is a mosquito-borne pathogen that was only endemic in Africa and south Asia until 2005 and 2006, when the virus spread into the Indian Ocean islands, Europe, and Asia. Autochthonous CHIKV transmission in the Caribbean islands was reported in December of 2013. In Panama, two febrile cases were detected in May of 2014: one traveling from Haiti, and the other traveling from the Dominican Republic. After other imported cases were detected, the first autochthonous case was reported in August of the same year. We detected CHIKV viral RNA and isolated the virus from serum samples. The phylogenetic analysis of the two imported isolates and one autochthonous CHIKV isolate indicated that the viruses belong to the Asian lineage in the Caribbean clade and are related to viruses recently identified in Saint Martin island, British Virgin Islands, China, and the Philippines. Although the circulating CHIKV lineages in the Americas have not yet been described, our results suggest that the Asian lineage is circulating in most American countries reporting autochthonous infection.