Unravelling heterogeneous malaria transmission dynamics in the Peruvian Amazon: insights from a cross-sectional survey.

BACKGROUND: Malaria remains a global health challenge, particularly in Peru's Loreto region. Despite ongoing efforts, high infection rates and asymptomatic cases perpetuate transmission. The Peruvian Ministry of Health's "Zero Malaria Plan" targets elimination. This novel study combines microscopic, molecular, and serological techniques to assess transmission intensity, identify epidemiological risk factors, and characterize species-specific patterns across villages. The findings aim to inform targeted interventions and support broader malaria elimination efforts in line with the Zero Malaria Plan initiative. METHODS: A cross-sectional malaria survey was conducted in the Zungarococha community, comprising the villages Llanchama (LL), Ninarumi (NI), Puerto Almendra (PA), and Zungarococha (ZG), using microscopic, molecular, and serological techniques to evaluate malaria transmission intensity. Statistical analysis, including multivariate-adjusted analysis, seroprevalence curves, and spatial clustering analysis, were performed to assess malaria prevalence, exposure, and risk factors. RESULTS: The survey revealed a high prevalence of asymptomatic infections (6% by microscopy and 18% by PCR), indicating that molecular methods are more sensitive for detecting asymptomatic infections. Seroprevalence varied significantly between villages, reflecting the heterogeneous malaria transmission dynamics. Multivariate analysis identified age, village, and limited bed net use as significant risk factors for malaria infection and species-specific exposure. Seroprevalence curves demonstrated community-specific patterns, with Llanchama and Puerto Almendra showing the highest seroconversion rates for both Plasmodium species. CONCLUSIONS: The study highlights the diverse nature of malaria transmission in the Loreto region, particularly nothing the pronounced heterogeneity as transmission rates decline, especially in residual malaria scenarios. The use of molecular and serological techniques enhances the detection of current infections and past exposure, aiding in the identification of epidemiological risk factors. These findings underscore the importance of using molecular and serological tools to characterize malaria transmission patterns in low-endemic areas, which is crucial for planning and implementing targeted interventions and elimination strategies. This is particularly relevant for initiatives like the Zero Malaria Plan in the Peruvian Amazon.

Seroprevalence of Trypanosoma cruzi among children from Veracruz, Mexico: Epidemiological baseline for a control model based on Chagas disease active transmission / Seroprevalencia de Trypanosoma cruzi en niños de Veracruz, México: línea epidemiológica de base para un modelo de control fundamentado de la transmisión activa de la enfermedad de Chagas.

Introduction. In 2021, the Secretaría de Salud de México and the Pan American Health Organization launched an initiative to interrupt intra-domiciliary vector transmission of Trypanosoma cruzi based on the prevalence of Chagas disease in children. The Mexican State of Veracruz was leading this initiative. Objective. To estimate the seroprevalence of T. cruzi infection among children under 15 years of age from rural areas of Veracruz, México. Materials and methods. We identified eight localities of high priority from the Municipality of Tempoal, Veracruz, for baseline serology. Blood samples were collected on filter paper from 817 individuals between June and August 2017, for screening with a third-generation enzyme immunoassay. Reactive cases were confirmed by indirect hemagglutination, enzyme-linked immunosorbent assay, and indirect immunofluorescence tests on peripheral blood serum samples. We calculated seroprevalence and 95% confidence intervals (CI). Results. We confirmed Chagas disease cases in children under 15 years of age with a seroprevalence of 1,9% (95 % CI = 1,12-3,16) in the localities of Citlaltepetl, Cornizuelo, Cruz de Palma and Rancho Nuevo. Conclusions. These results indicate recent transmission of T. cruzi in these communities and allow to establish an epidemiological baseline for the design and implementation of a model focused on geographical areas with active transmission to advance toward the elimination of intra-domiciliary vector transmission of this parasite in Mexico.

Introducción. En el 2021, la Secretaría de Salud de México y la Organización Panamericana de la Salud lanzaron una iniciativa para interrumpir la transmisión vectorial intradomiciliaria de Trypanosoma cruzi, fundamentada en la prevalencia de la enfermedad de Chagas en la población infantil. El estado mexicano de Veracruz fue el pionero de esta iniciativa. Objetivo. Estimar la seroprevalencia de infección por T. cruzi en menores de 15 años de localidades rurales de Veracruz, México. Materiales y métodos. Se identificaron ocho localidades prioritarias para la serología basal del municipio de Tempoal, Veracruz. Entre junio y agosto de 2017, se recolectaron muestras de sangre en papel filtro de 817 individuos para su tamizaje mediante un inmunoensayo enzimático de tercera generación. Los casos reactivos del tamizaje se confirmaron mediante pruebas de hemaglutinación indirecta, ensayo de inmunoabsorción ligado a enzimas e inmunofluorescencia indirecta en muestras de suero. Se calculó la seroprevalencia y su intervalo de confianza (IC) del 95 %. Resultados. En las localidades de Citlaltépetl, Cornizuelo, Cruz de Palma y Rancho Nuevo se confirmaron casos de la enfermedad de Chagas en menores de 15 años con una seroprevalencia de 1,9 % (IC 95 % = 1,12-3,16). Conclusiones. Los resultados indican que estas comunidades presentan transmisión reciente de T. cruzi y permiten establecer una línea epidemiológica de base para el diseño e implementación de un modelo dirigido a aquellas áreas geográficas con transmisión activa. Se espera que dicho modelo contribuya a la eliminación de la transmisión vectorial intradomiciliaria del tripanosomátido en México.

Seroprevalencia de SARS-CoV-2 en dos instituciones penitenciarias de Paraguay en el periodo abril-mayo del 2022

Introducción. La pandemia de COVID-19 ha puesto al descubierto muchas de las desigualdades en la sociedad y una de las poblaciones vulnerables más desatendidas son las privadas de libertad. Objetivo. Determinar la seroprevalencia de SARS-CoV-2 en población privada de libertad (PPL) en dos instituciones penitenciarias de Paraguay entre abril a mayo de 2022. Materiales y métodos. Estudio descriptivo transversal en dos instituciones penitenciarias de Paraguay, una de varones y otra de mujeres, mediante un muestreo probabilístico bietápico. Las muestras sanguíneas se tomaron por punción dactilar para la determinación de anticuerpos anti SARS-CoV-2 por una prueba rápida IgG/IgM (Orient Gene Biotech COVID-19 casete). Para el análisis de datos se utilizó estadística descriptiva (media, desviación estándar y porcentajes) y analítica (prueba de chi cuadrado). Resultados. Se incluyeron 602 PPL, 67% varones y 33% mujeres, la media de edad fue de 34 años (DE 10,71), 21% (n=124) con comorbilidad, 31% (n=186) con vacunación completa. De los 66 PPL (11%) que informaron infección previa de Covid-19, 79% (n=52) desarrolló síntomas y 6% (n=4) requirió hospitalización. El 95% (IC95%: 92,18-96,58) presentó serología positiva (IgG y/o IgM) para SARS-CoV-2 en hombres y 94% (IC95%: 89,65-96,83) en mujeres. En el grupo de vacunados la seropositividad fue 98,5% (IC95%: 97,11-99,25) y entre los no vacunados 57% (IC95%: 53,22-70,29). Conclusión. La seroprevalencia de SARS-CoV-2 fue similar a lo reportado en otros estudios. La insalubridad estructural y hacinamiento son factores que potencian la dispersión del virus y enfatiza la importancia de incentivar la vacunación en estas poblaciones.

Introduction. The COVID-19 pandemic has exposed many of the inequalities in society and one of the most neglected vulnerable populations are those deprived of their liberty. Objective. Determine the seroprevalence of SARS-CoV-2 in the population deprived of liberty (PDL) in two penitentiary institutions in Paraguay between April-May 2022. Materials and methods. Cross-sectional descriptive study in two penitentiary institutions in Paraguay, one for men and the other one for women, using two-stage probabilistic sampling. The blood samples were taken by fingerprint for the determination of anti-SARS-CoV-2 antibodies by a rapid IgG/IgM test (Orient Gene Biotech COVID-19 cassette). Descriptive statistics (mean, standard deviation (SD), percentages) and analytical statistics (chi square test) were used for data analysis. Results. A total of 602 PDL were included, 67% men and 33% women, the average age was 34 years (SD 10.71), 21% (n=124) with comorbidity, 31% (n=186) with complete vaccination. Of the 66 PPL (11%) who reported prior Covid-19 infection, 79% (n=52) developed symptoms and 6% (n=4) required hospitalization. In men, 95% presented positive serology (IgG and/or IgM) for SARS-CoV-2 (95% CI: 92.18-96.58) and 94% (95% CI: 89.65-96.83) in women. In the vaccinated group, seropositivity was 98.5% (95% CI: 97.11-99.25), and among the unvaccinated, 57% (95% CI: 53.22-70.29). Conclusion. The seroprevalence of SARS-CoV-2 was similar to that reported in other studies. The structural unhealthiness and overcrowding are factors that enhance the spread of the virus and emphasize the importance of encouraging vaccination in these populations.

The decline of measles antibody titers in previously vaccinated adults: a cross-sectional analysis

ABSTRACT The global reemergence of measles in 2018-2019 reinforces the relevance of high-coverage immunization to maintain the disease elimination. During an outbreak in the Sao Paulo State in 2019, several measles cases were reported in individuals who were adequately vaccinated according to the current immunization schedule recommends. This study aimed to assess measles IgG antibody seropositivity and titers in previously vaccinated adults. A cross-sectional study was conducted at CRIE-HC-FMUSP (Sao Paulo, Brazil) in 2019. It included healthy adults who had received two or more Measles-Mumps-Rubella vaccines (MMR) and excluded individuals with immunocompromising conditions. Measles IgG antibodies were measured and compared by ELISA (Euroimmun®) and chemiluminescence (LIASON®). The association of seropositivity and titers with variables of interest (age, sex, profession, previous measles, number of measles-containing vaccine doses, interval between MMR doses, and time elapsed since the last MMR dose) was analyzed. A total of 162 participants were evaluated, predominantly young (median age 30 years), women (69.8%) and healthcare professionals (61.7%). The median interval between MMR doses was 13.2 years, and the median time since the last dose was 10.4 years. The seropositivity rate was 32.7% by ELISA and 75.3% by CLIA, and a strong positive correlation was found between the tests. Multivariate analyses revealed that age and time since the last dose were independently associated with positivity. Despite being a single-center evaluation, our results suggest that measles seropositivity may be lower than expected in adequately immunized adults. Seropositivity was higher among older individuals and those with a shorter time since the last MMR vaccine dose.

Association between hepatitis A seropositivity and bone mineral density in adolescents and adults: a cross-sectional study using NHANES data

ABSTRACT BACKGROUND: Osteoporosis, characterized by decreased bone density and increased fracture risk, imposes significant physical, psychosocial, and financial burdens. Early detection and prevention are crucial for managing osteoporosis and reducing the risk of fractures. OBJECTIVES: To investigate the relationship between Hepatitis A seropositivity and bone mineral density (BMD) in adolescents and adults and to explore the potential link between Hepatitis A infection and osteoporosis risk. DESIGN AND SETTING: This cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018 to evaluate the association between hepatitis A seropositivity and BMD in 15,693 participants. METHODS: Multivariable regression analysis was used to calculate the mean BMD and standard error for adolescents and adults, followed by an independent z-test to determine whether there was a significant difference between the seropositive and seronegative groups. RESULTS: Hepatitis A seropositive adolescents and adults had lower BMD than their seronegative counterparts, with significant differences in lumber spine (mean difference = -0.03 g/cm2, P < 0.01 for both age groups) and pelvis BMDs (mean difference = -0.02 g/cm2, P < 0.01 for the adult age groups), after adjusting for various covariates. CONCLUSIONS: This study confirmed that both adolescent and adult individuals seropositive for Hepatitis A antibodies had reduced BMD among both adolescents and adults, especially in the adult group. This finding suggests a possible link between Hepatitis A infection and risk of osteoporosis.

Chlamydia psittaci seropositivity in workers exposed to birds and review of the literature: Evidence of circulation in Antioquia / Seropositividad de Chlamydia psittaci en trabajadores expuestos a aves y revisión de la literatura: evidencia de circulación en Antioquia.

Introduction: Psittacosis is a zoonotic disease caused by Chlamydia psittaci, a bacterium classified as an agent with bioterrorist potential. It has caused multiple outbreaks in exposed poultry workers around the world. Colombia has no epidemiological follow-up of the infection and a big knowledge gap. Objectives: To determine the antibodies' frequency against C. psittaci in workers with occupational exposure to birds and to review the literature on studies conducted in Colombia. Materials and methods: We conducted a cross-sectional descriptive study with analytical intent on workers in contact with birds and reviewed the related literature in Colombia. IgM and IgG serum antibodies against C. psittaci were detected by microimmunofluorescence. The sociodemographic and exposure characteristics were expressed as frequencies and summary measures. Associated factors were explored by bivariate and multivariate analysis. The scientific and gray literature review was done with a structured search. Results: We analyzed 54 workers in contact with birds. Antibody prevalence was 31.5%. Slaughtering and evisceration by non-veterinarians was a risk factor for antibody presence. There are only four previous studies on C. psittaci in Colombia. Conclusions: Here, we present the first evidence of C. psittaci circulation among workers exposed to birds in Antioquia and the second report in the country. These findings contribute to the "One Health" public health strategy.

Introducción: La psitacosis es una enfermedad zoonótica causada por Chlamydia psittaci. Esta bacteria es catalogada como un agente con potencial bioterrorista y ha causado múltiples brotes en trabajadores con exposición laboral a aves en diferentes lugares del mundo. En Colombia, no se hace seguimiento epidemiológico de la infección y existe una gran brecha en el conocimiento. Objetivos: Determinar la frecuencia de anticuerpos contra C. psittaci en trabajadores con exposición laboral a aves y sus factores asociados. Además, revisar la literatura en relación con los estudios sobre el tema realizados en Colombia. Materiales y métodos: Se llevó a cabo un estudio descriptivo, transversal, con intención analítica, en trabajadores en contacto con aves y se revisó la literatura científica relacionada en Colombia. Se detectaron anticuerpos IgM e IgG contra C. psittaci en suero por microinmunofluorescencia. La descripción de las características sociodemográficas y de exposición se hizo con frecuencias y medidas de resumen. Se exploraron factores asociados por análisis bivariados y multivariados. La revisión de la literatura científica y gris se hizo con búsqueda estructurada. Resultados: Se analizaron 54 trabajadores en contacto con aves y se encontró una prevalencia de anticuerpos del 31,5 %. El ejercer funciones de sacrificio y faenado de las aves sin ser médico veterinario fue un factor de riesgo para la presencia de anticuerpos. Solo se encontraron cuatro estudios previos sobre C. psittaci hechos en Colombia. Conclusiones: Este estudio constituye la primera evidencia de la circulación de C. psittaci en trabajadores en contacto con aves en Antioquia y el segundo reporte en el país. Estos hallazgos aportan desde la salud pública a la estrategia One Health.

Prevalencia de toxoplasmosis en niños de entre uno y seis años de edad

Fundamento: la toxoplasmosis adquirida en niños durante los primeros años de vida es la consecuencia de la transmisión por vía oral de esta parasitosis. Objetivo: determinar la prevalencia de infección por Toxoplasma gondii en niños en los primeros años de vida y relacionarlos con variables epidemiológicas de infestación. Métodos: estudio descriptivo y transversal para examinar la presencia de anticuerpos IgG anti-Toxoplasma gondii en niños de uno a seis años de edad en el área rural del municipio Cueto durante el periodo 2020-2021. Se utilizó un muestreo probabilístico por cuotas y se recopilaron variables demográficas y epidemiológicas. Se obtuvo una muestra de 200 niños, a los que se les tomó suero a través de venopunción. Se utilizó la técnica de IFI para determinar la presencia de anticuerpos IgG anti-Toxoplasma gondii y se aplicó la prueba no paramétrica Chi-Cuadrado de Pearson para comprobar hipótesis de investigación. Resultados: la seropositividad a T. gondii fue de un 58 % en la muestra estudiada; se encontró relación entre la infestación y la convivencia con gatos domésticos y con la procedencia del agua. No se encontraron diferencias significativas en la prevalencia de T. gondii en relación con la edad, el sexo, nivel social, cultural y la higiene ambiental, consumo de carnes, frutas y hortalizas, convivencias con animales de corral. Conclusiones: se evidencia seroprevalencia a T. gondii en la población infantil de uno a seis años de edad y su relación con la procedencia del agua y la convivencia con gatos.

Foundation: acquired toxoplasmosis in children during the first years of life is the consequence of the oral transmission of this parasitosis. Objective: to determine the prevalence of Toxoplasma gondii infection in children in the first years of life and relate them to epidemiological variables of infestation. Methods: descriptive and cross-sectional study to examine the presence of IgG anti-Toxoplasma gondii antibodies in children from one to six years of age in the rural area of ​​the Cueto municipality during the period 2020-2021. Quota probabilistic sampling was used and demographic and epidemiological variables were collected. A sample of 200 children was obtained, from whom serum was taken through venipuncture. The IFI technique was used to determine the presence of IgG anti-Toxoplasma gondii antibodies and the Pearson Chi-Square non-parametric test was applied to verify research hypotheses. Results: seropositivity to T. gondii was 58% in the studied sample; A relationship was found between the infestation and the coexistence with domestic cats and with the origin of the water. No significant differences were found in the prevalence of T. gondii in relation to age, sex, social and cultural level, and environmental hygiene, consumption of meat, fruit, and vegetables, and living with farm animals. Conclusions: T. gondii seroprevalence is evidenced in the child population from one to six years of age and its relationship with the source of water and living with cats.

Severe acute respiratory syndrome coronavirus 2 seroprevalence among patients with pulmonary tuberculosis

SUMMARY OBJECTIVE: The objective of this study was to estimate the seroprevalence of severe acute respiratory syndrome coronavirus 2 antibodies in patients with tuberculosis. METHODS: This cross-sectional study was conducted at an outpatient tuberculosis clinic in Alvorada, RS, Brazil, with data collection between October and December 2020. Outpatients aged>18 years with active pulmonary tuberculosis, no prior history of coronavirus disease 2019, and no suspected coronavirus disease 2019 were included in the study. Whole blood samples were collected to perform the severe acute respiratory syndrome coronavirus 2 antibodies test. RESULTS: During the study period, 52 patients met the inclusion and were included in the analysis. Severe acute respiratory syndrome coronavirus 2 antibodies were positive in 16 (30.8%) patients. Male sex was more frequent among patients with negative severe acute respiratory syndrome coronavirus 2 antibodies than in patients with positive severe acute respiratory syndrome coronavirus 2 antibodies (86.1 vs. 56.3%, p=0.031). Contact with coronavirus disease 2019 case was more common in patients with positive severe acute respiratory syndrome coronavirus 2 antibodies compared with patients with negative severe acute respiratory syndrome coronavirus 2 antibodies (87.5 vs. 8.3%, p<0.0001). In a multivariate analysis, in a model including the variables such as male sex and contact with coronavirus disease 2019 case, only contact with coronavirus disease 2019 was independently associated with positive severe acute respiratory syndrome coronavirus 2 antibodies (OR 77.0, 95%CI 11.5-512.4, p<0.0001). CONCLUSION: This study revealed a seroprevalence of 30.8% severe acute respiratory syndrome coronavirus 2 among patients with tuberculosis.

Seropositividad de Chlamydia psittaci en trabajadores expuestos a aves y revisión de la literatura: evidencia de circulación en Antioquia / Chlamydia psittaci seropositivity in workers exposed to birds and review of the literature: Evidence of circulation in Antioquia

Introducción. La psitacosis es una enfermedad zoonótica causada por Chlamydia psittaci. Esta bacteria es catalogada como un agente con potencial bioterrorista y ha causado múltiples brotes en trabajadores con exposición laboral a aves en diferentes lugares del mundo. En Colombia, no se hace seguimiento epidemiológico de la infección y existe una gran brecha en el conocimiento. Objetivos. Determinar la frecuencia de anticuerpos contra C. psittaci en trabajadores con exposición laboral a aves y sus factores asociados. Además, revisar la literatura en relación con los estudios sobre el tema realizados en Colombia. Materiales y métodos. Se llevó a cabo un estudio descriptivo, transversal, con intención analítica, en trabajadores en contacto con aves y se revisó la literatura científica relacionada en Colombia. Se detectaron anticuerpos IgM e IgG contra C. psittaci en suero por microinmunofluorescencia. La descripción de las características sociodemográficas y de exposición se hizo con frecuencias y medidas de resumen. Se exploraron factores asociados por análisis bivariados y multivariados. La revisión de la literatura científica y gris se hizo con búsqueda estructurada. Resultados. Se analizaron 54 trabajadores en contacto con aves y se encontró una prevalencia de anticuerpos del 31,5 %. El ejercer funciones de sacrificio y faenado de las aves sin ser médico veterinario fue un factor de riesgo para la presencia de anticuerpos. Solo se encontraron cuatro estudios previos sobre C. psittaci hechos en Colombia. Conclusiones. Este estudio constituye la primera evidencia de la circulación de C. psittaci en trabajadores en contacto con aves en Antioquia y el segundo reporte en el país. Estos hallazgos aportan desde la salud pública a la estrategia One Health.

Introduction. Psittacosis is a zoonotic disease caused by Chlamydia psittaci, a bacterium classified as an agent with bioterrorist potential. It has caused multiple outbreaks in exposed poultry workers around the world. Colombia has no epidemiological follow-up of the infection and a big knowledge gap. Objectives. To determine the antibodies' frequency against C. psittaci in workers with occupational exposure to birds and to review the literature on studies conducted in Colombia. Materials and methods. We conducted a cross-sectional descriptive study with analytical intent on workers in contact with birds and reviewed the related literature in Colombia. IgM and IgG serum antibodies against C. psittaci were detected by microimmunofluorescence. The sociodemographic and exposure characteristics were expressed as frequencies and summary measures. Associated factors were explored by bivariate and multivariate analysis. The scientific and gray literature review was done with a structured search. Results. We analyzed 54 workers in contact with birds. Antibody prevalence was 31.5%. Slaughtering and evisceration by non-veterinarians was a risk factor for antibody presence. There are only four previous studies on C. psittaci in Colombia. Conclusions. Here, we present the first evidence of C. psittaci circulation among workers exposed to birds in Antioquia and the second report in the country. These findings contribute to the "One Health" public health strategy.

Seroprevalence of human toxocariasis in Latin America and the Caribbean: a systematic review and meta-analysis.

Introduction: The current study aimed to quantitatively synthesize available evidence regarding the seroprevalence of human toxocariasis in Latin America and the Caribbean. Methods: A systematic research involving six electronic databases was conducted using a research strategy that combined MeSH terms with free terms. Article selection and information extraction were performed using a double and independent approach. The Newcastle-Ottawa tool was used to assess the risk of bias in the included articles. The meta-analysis used the random-effects approach, with subgroup analysis and sensitivity analysis for risk of bias also being performed. Results: We included 101 articles with a total of 31,123 participants. The studies were conducted between 1990 and 2022, with Brazil accounting for the largest number of studies (n = 37). The overall seroprevalence of human toxocariasis was 31.0% (95% CI: 27.0-35.0%, I2 = 99%). The prevalence of the main characteristics observed in seropositive patients were as follows: ocular toxocariasis (30.0%), asymptomatic (26.0%), and presence of dogs at home (68.0%). In addition, the seroprevalence was lower in studies including only adults than in those including children or both. In contrast, no differences in seroprevalences were found between studies conducted in the community and hospital. Conclusion: The overall seroprevalence of human toxocariasis in Latin America and the Caribbean was high. Notably, our findings showed that the seroprevalence was increased among populations who kept a dog at home but was decreased in populations comprising only adults. Our findings can be used to establish epidemiological surveillance strategies for the prevention and early identification of toxocariasis.

Vigilancia serológica de la zoonosis parasitaria en 13 regiones de la sierra del Perú: Periodo 2016-2019 / Serological surveillance of parasitic zoonoses in 13 highlands regions of Peru: Period 2016-2019

RESUMEN Objetivos. Determinar la seropositividad a anticuerpos anti-IgG por infección de Echinococcus granulosus, Fasciola hepatica y cisticerco de Taenia solium y describir las características de los infectados en 13 regiones de la sierra peruana entre 2016 y 2019. Materiales y métodos. Estudio observacional transversal, que analizó 7811 fichas epidemiológicas de la vigilancia basada en laboratorio de las zoonosis parasitarias del periodo 2016-2019. El diagnóstico se realizó mediante la detección de anticuerpos tipo IgG anti E. granulosus, F. hepatica y cisticerco de T. solium utilizando antígenos nativos mediante el ensayo inmunoabsorbente ligado a enzimas (ELISA) e Inmunoblot. La diferencia en la frecuencia de casos de estas zoonosis según características identificadas se realizó mediante la prueba chi-cuadrado de Pearson y prueba exacta de Fisher. Resultados. Se determinó una seropositividad de 7,9% para fascioliasis, 4,9% para equinococosis quística, y 2,3% para cisticerco de T. solium. Estas frecuencias fueron mayores en Cerro de Pasco para equinococosis quística (24,5%), en Ayacucho para cisticerco de T. solium (4,5%) y en Puno para fascioliasis (40,6%). Entre las características sociodemográficas, se encontró una diferencia estadísticamente significativa en la frecuencia de casos para todas las zoonosis según grupo etario, ocupación, y región de residencia. Además, se encontró diferencia con el consumo de verduras en emolientes, y entre las características clínico-epidemiológicas con tener antecedentes familiares de las zoonosis parasitarias. Conclusiones. A partir de las 7811 muestras evaluadas, se encontró que estas zoonosis parasitarias están distribuidas en 13 regiones de la sierra del Perú, ocasionando un problema de salud importante, con frecuencias que varían según diversas características.

ABSTRACT Objectives. To determine seropositivity to anti-IgG antibodies against Echinococcus granulosus, Fasciola hepatica and Taenia solium cysticercus infection and to describe the characteristics of the infected patients in 13 regions of the Peruvian highlands between 2016 and 2019. Materials and methods. Cross-sectional, observational study, in which we analyzed 7811 epidemiological records of laboratory-based surveillance of parasitic zoonoses from 2016 to 2019. Diagnosis was established by detecting IgG type anti-E. granulosus, F. hepatica and T. solium cysticercus antibodies using native antigens by enzyme-linked immunosorbent assay (ELISA) and Immunoblot. We evaluated the difference in the frequency of the cases according to identified characteristics using Pearson's chi-square test and Fisher's exact test. Results. Seropositivity was 7.9% for fascioliasis, 4.9% for cystic echinococcosis, and 2.3% for T. solium cysticercus. These rates were higher in Cerro de Pasco for cystic echinococcosis (24.5%), in Ayacucho for T. solium cysticercus (4.5%) and in Puno for fascioliasis (40.6%). Regarding the sociodemographic characteristics, we found a statistically significant difference in the frequency of cases for all zoonoses according to age group, occupation, and region of residence. We also found a difference with the consumption of vegetables in emollients, and between clinical-epidemiological characteristics and having a family history of parasitic zoonoses. Conclusions. From the 7811 samples, we found that these parasitic zoonoses are distributed in 13 regions of the Peruvian highlands, and represent a major health problem, with frequencies that change according to different characteristics.

Chikungunya seroprevalence in population-based studies: a systematic review and meta-analysis.

BACKGROUND: Seroprevalence studies about chikungunya infection are usually conducted after epidemics to estimate the magnitude of the attack. This study aimed to estimate the seroprevalence of CHIKV by WHO region, considering the periods of introduction of the virus in these regions and its potential to lead to epidemics. METHODS: We systematically reviewed Medline/Pubmed, Embase, Lilacs, Scopus and Web of Science for original articles published up to 2020. Cohort, case-control and cross-sectional studies were eligible for inclusion, based on the results of laboratory diagnosis of previous or previous and recent infection. Those conducted with symptomatic individuals were excluded. RESULTS: 596 articles were identified, 197 full-text were reviewed and 64 were included, resulting in 71 seroprevalences. Most were cross-sectional studies (92%), between 2001 and 2020 (92%), with population of all ages (55%), conducted in Kenya (10.9%), Brazil (9.4%) and French Polynesia (7.8%). The pooled estimates were 24% (95%CI 19-29; I2 = 99.7%; p < 0.00), being 21% (95%CI 13-30; I2 = 99.5%; p < 0.00) for adults, 7% (95%CI 0-23; I2 = 99.7%; p < 0.00) for children and 30% (95%CI 23-38; I2 = 99.7%; p < 0.00) for all ages. The higher seroprevalences were found in African, the Americas and South-East Asian Regions. CONCLUSIONS: The great heterogeneity of seroprevalences points to the persistence of viral circulation. Even where the seroprevalence is high, the population replacement and the absence of vaccines mean that the risk of virus spread and epidemics remains. REGISTRATION: PROSPERO CRD42020166227.

Dynamics of SARS-CoV-2 seroprevalence during the first year of the COVID-19 pandemic in the Northeast region of Brazil.

In this household-based seroepidemiological survey, we analyzed the dynamics of SARS-CoV-2 seroprevalence during the first year of the COVID-19 pandemic in Sergipe State, Northeast Brazil, the poorest region of the country. A total of 16,547 individuals were tested using a rapid IgM-IgG antibody test and fluorescence immunoassay (FIA). Seroprevalence rates were presented according to age, sex, and geographic region. A comparative analysis was performed between the results obtained in July 2020 (peak of the first wave), August - November 2020 (end of the first wave), and February - March 2021 (beginning of the second wave). Seroprevalence rates in the three phases were estimated at 9.3% (95% CI 8.5-10.1), 12.0% (95% CI 11.2-12.9) and 15.4% (95% CI 14.5-16.4). At the end of the first wave, there was a rise in seroprevalence in the countryside (p < 0.001). At the beginning of the second wave, we found an increase in seroprevalence among women (p < 0.001), adults aged 20 to 59 years (p < 0.001), and the elderly (p < 0.001). In this phase, we found an increase in estimates both in metropolitan areas and in the countryside (p < 0.001). This study showed an increase in SARS-CoV-2 seroprevalence over the first year of the pandemic, with approximately one in six people having anti-SARS-CoV-2 antibodies at the beginning of the second wave of COVID-19. Furthermore, our results suggest a rapid spread of COVID-19 from metropolitan areas to the countryside during the first months of the pandemic.

Niveles de protección contra Haemophilus influenzae tipo b en niños, adolescentes y adultos cubanos / Levels of protection against Haemophilus influenzae type b in Cuban children, adolescents and adults

La concentración de los anticuerpos contra el polisacárido capsular polirribosilribitol fosfato del Haemophilus influenzae tipo b se considera un buen indicador serológico para evaluar protección contra la enfermedad invasiva. Existen pocos reportes que estudien la inmunidad serológica en Cuba. El objetivo general de este estudio fue determinar los niveles de protección séricos contra Haemophilus influenzae tipo b en niños, adolescentes y adultos cubanos, en una muestra de 575 individuos. Se cuantificó la concentración de IgG anti-polirribosilribitol fosfato de Haemophilus influenzae tipo b mediante un inmunoensayo enzimático estandarizado y validado en el laboratorio de inmunología del Centro Nacional de Genética Médica, La Habana, Cuba. Se determinaron las concentraciones medias geométricas de anticuerpos y los niveles de protección frente a la enfermedad invasiva por Haemophilus influenzae tipo b. La concentración media geométrica de IgG anti-polirribosilribitol fosfato fue de 1,94 μg/mL (IC95 por ciento 1,80; 2,08) y fue mayor en el grupo de 16 a 22 años. El porcentaje con protección de larga duración fue mayor para el sexo femenino que para el masculino (82,2 por ciento vs 71,4 por ciento; p=0,0339) entre los que poseían inmunidad natural. El grupo de sujetos nacidos en el periodo en que se vacunó con la vacuna conjugada cubana QUIMI-HIB® presentó concentraciones medias geométricas superiores (2,75 μg/mL, IC95 por ciento 2,00; 3,79). El 99,1 por ciento de los participantes presentó protección frente a la enfermedad invasiva por Haemophilus influenzae tipo b, el 19,8 por ciento a corto plazo y el 79,3 por ciento protección de larga duración. El inmunoensayo validado para la cuantificación de IgG anti-polirribosilribitol fosfato podría emplearse en estudios de seroprevalencia. En los sujetos estudiados, se encontró un predominio de elevadas concentraciones de IgG anti- polirribosilribitol fosfato del Haemophilus influenzae tipo b que confieren protección de larga duración(AU)

The levels of antibodies directed against the capsular polysaccharide polyribosylribitol phosphate of Haemophilus influenzae type b are considered a good serological indicator to assess the immunity against invasive disease. In Cuba, there are few reports that study serological immunity. The general objective was to determine serum protection levels against Haemophilus influenzae type b in Cuban children, adolescents and adults, in a sample of 575 Cuban individuals. The concentration of IgG against Haemophilus influenzae type b was quantified by means of an indirect ELISA standardized and validated in the immunology laboratory of the National Center of Medical Genetics, Havana, Cuba. The geometric mean concentration of IgG anti- polyribosylribitol phosphate and the levels of protection against invasive Haemophilus influenzae type b disease were determined. The geometric mean concentration of IgG anti- polyribosylribitol phosphate was 1.94 μg/mL (95percentCI 1.80;2.08) and the group from 16 to 22 years old presented the highest. Among those with natural immunity, the percentage with long-term protection was higher for females vs. males (82.2percent vs. 71.4percent; p=0.0339). The group of subjects born in the period in which they were vaccinated with the Cuban conjugate vaccine QUIMI-HIB® presented higher geometric mean concentration (2.75 μg/mL, CI95percent 2.00; 3.79). The 99.1percent of the participants had protection against invasive Haemophilus influenzae type b disease, 19.8percent short-term and 79.3percent long-term protection. The ELISA for the quantification of anti- Haemophilus influenzae type b IgG antibodies, developed and validated, could be used in seroprevalence studies. In the subjects studied, there was a predominance of high IgG anti- Haemophilus influenzae type b polyribosylribitol phosphate concentration values that confer long-term protection(AU)

Seroprevalence of SARS-CoV-2 antibodies in schoolchildren in the city of São Paulo, 2020 / Soroprevalência de anticorpos do vírus SARS-CoV-2 em escolares no município de São Paulo, 2020

ABSTRACT OBJECTIVE To estimate seroprevalence of SARS-CoV-2 antibodies in schoolchildren aged 4 to 14 years living in the city of São Paulo, according to clinical, demographic, epidemiological, and social variables, during the school closure period as a measure against covid-19 spread. METHODS A serological survey was made in September 2020 with a random sample stratified by school system (municipal public, state public and private) type. A venous blood sample was collected using the Wondfo SARS-CoV-2 Antibody Test (lateral flow method) for detection of total SARS-CoV-2 virus antibodies. Semi-structured questionnaires were applied to collect clinical, demographic, social, and epidemiological data. RESULTS Seroprevalence of SARS-CoV-2 antibodies in schoolchildren was of 16.6% (95%CI 15.4-17.8). The study found higher seroprevalence in the municipal (18.5%; 95%CI 16.6-20.6) and state (16.2%; 95%CI 14.4-18.2) public school systems compared to the private school system (11.7; 95%CI 10.0-13.7), among black and brown students (18.4%; 95%CI 16.8-20.2) and in the most vulnerable social stratum (18.5 %;95%CI 16.9-20.2). Lower seroprevalence was identified in schoolchildren who reported following the recommended protective measures against covid-19. CONCLUSION Seroprevalence of SARS-CoV-2 antibodies is found mainly in the most socially vulnerable schoolchildren. This study can contribute to support public policies that reinforce the importance of suspending face-to-face classes and developing strategies aimed at protective measures and monitoring of the serological status of those who have not yet been included in the vaccination schedule.

RESUMO OBJETIVO Estimar a soroprevalência de anticorpos do vírus SARS-CoV-2 em escolares de quatro a 14 anos de idade residentes no município de São Paulo, segundo variáveis clínicas, demográficas, epidemiológicas e sociais, durante o período de fechamento das escolas como medida de controle da covid-19. MÉTODOS Realizou-se um inquérito sorológico em setembro de 2020 com amostra aleatória estratificada por tipo de rede de ensino (pública municipal, pública estadual e privada). Foi coletada amostra de sangue venoso utilizando-se o teste de imunoensaio de fluxo lateral da fabricante Wondfo para detecção de anticorpos totais contra o vírus SARS-CoV-2. Aplicaram-se questionários semiestruturados para o levantamento de dados clínicos, demográficos, sociais e epidemiológicos. RESULTADOS A soroprevalência de anticorpos do vírus SARS-CoV-2 em escolares foi de 16,6% (IC95% 15,4-17,8). O estudo encontrou soroprevalências mais elevadas na rede pública municipal (18,5%; IC95% 16,6-20,6) e estadual (16,2%; IC95% 14,4-18,2) em relação à rede privada (11,7; IC95% 10,0-13,7) e entre escolares da raça/cor preta e parda (18,4%; IC95% 16,8-20,2) e no estrato social mais vulnerável (18,5%; IC95% 16,9-20,2). A pesquisa identificou menores soroprevalências nos escolares que relataram seguir as medidas recomendadas de proteção contra a covid-19. CONCLUSÃO A soroprevalência de anticorpos contra o vírus SARS-CoV-2 atinge principalmente os escolares socialmente mais vulneráveis. Este estudo pode contribuir para embasar políticas públicas que reforcem a importância da suspensão das aulas presenciais e da necessidade de estratégias de medidas de proteção e acompanhamento do status sorológico daqueles que ainda não foram contemplados no calendário vacinal.

Seroepidemiology of SARS-CoV-2 on a partially vaccinated island in Brazil: Determinants of infection and vaccine response.

Background: A vaccination campaign targeted adults in response to the pandemic in the City of Rio de Janeiro. Objective: We aimed to evaluate the seroprevalence of SARS-CoV-2 antibodies and identify factors associated with seropositivity on vaccinated and unvaccinated residents. Methods: We performed a seroepidemiologic survey in all residents of Paquetá Island, a neighborhood of Rio de Janeiro city, during the COVID-19 vaccine roll-out. Serological tests were performed from June 16 to June 19, 2021, and adjusted seropositivity rates were estimated by age and epidemiological variables. Logistic regression models were used to estimate adjusted ORs for risk factors to SARS-CoV-2 seropositivity in non-vaccinated individuals, and potential determinants of the magnitude of antibody responses in the seropositive population. Results: We included in the study 3,016 residents of Paquetá (83.5% of the island population). The crude seroprevalence of COVID-19 antibodies in our sample was 53.6% (95% CI = 51.0, 56.3). The risk factors for SARS-CoV-2 seropositivity in non-vaccinated individuals were history of confirmed previous COVID-19 infection (OR = 4.74; 95% CI = 3.3, 7.0), being a household contact of a case (OR = 1.93; 95% CI = 1.5, 2.6) and in-person learning (OR = 2.01; 95% CI = 1.4, 3.0). Potential determinants of the magnitude of antibody responses among the seropositive were hybrid immunity, the type of vaccine received, and time since the last vaccine dose. Being vaccinated with Pfizer or AstraZeneca (Beta = 2.2; 95% CI = 1.8, 2.6) determined higher antibody titers than those observed with CoronaVac (Beta = 1.2; 95% CI = 0.9, 1.5). Conclusions: Our study highlights the impact of vaccination on COVID-19 collective immunity even in a highly affected population, showing the difference in antibody titers achieved with different vaccines and how they wane with time, reinforcing how these factors should be considered when estimating effectiveness of a vaccination program at any given time. We also found that hybrid immunity was superior to both infection-induced and vaccine-induced immunity alone, and online learning protected students from COVID-19 exposure.

Seroprevalencia de SARS-CoV-2 y factores asociados en migrantes con vocación de permanencia, Bucaramanga, Colombia / SARS-CoV-2 seroprevalence and associated factors among migrants with a vocation for permanence, Bucaramanga, Colombia / Soroprevalência de SARS-CoV-2 e fatores associados em migrantes com vocação de permanência, Bucaramanga, Colômbia

Introducción: Existen pocos reportes que evalúen la seroprevalencia contra SARS-CoV-2 en población migrante en el mundo. Estos estudios ayudan a conocer la exposición al virus en las poblaciones para implementar acciones que reduzcan el impacto de la infección por SARS-CoV-2. Objetivo: Determinar la seroprevalencia contra SARS CoV-2 en migrantes con vocación de permanencia en Bucaramanga, e identificar factores asociados a la infección previa por SARS-CoV-2. Materiales y métodos: Estudio de corte transversal analítico con muestreo consecutivo. Se incluyeron migrantes adultos en Bucaramanga durante febrero/2021. Se realizaron encuestas e inmunoensayos de quimioluminiscencia para IgM e IgG contra SARS-CoV-2 en suero. Se calcularon razones de prevalencia (RP) con regresión log-binomial. Resultados:Se incluyeron 462 participantes. La seroprevalencia de IgM fue 11,7% (IC95% 9,1­14,9), de IgG fue 32,9% (IC95% 28,8­37,3) y de IgM o IgG fue 36,1% (IC95% 31,9-40,6). Exposición a un caso confirmado (RP:1,54; IC95%1,04-2,29) o sospechoso (RP:1,56; IC95%1,13-2,16) de COVID-19, seis o más convivientes (RP:1,52; IC95%1,05-2,20), estancia en Colombia ≥2 años (RP:1,43; IC95%1,11-1,92) y presencia de síntomas (RP:1,62; IC95%1,26 - 2,10) se asociaron con mayor seroprevalencia de IgG. Discusión:En Bucaramanga, la seroprevalencia en migrantes fue similar a la de migrantes en Kuwait, pero menor que en Paris y Singapur. Conclusión: En migrantes con vocación de permanencia la seroprevalencia contra SARS-CoV-2 fue similar a la reportada en residentes de Bucaramanga. El contacto con casos sospechosos/confirmados de COVID-19 y las condiciones de hacinamiento fueron algunos de los factores asociados a la seroprevalencia.

Introduction:There are few reports assessing anti-SARS-CoV-2 seroprevalence in the migrant population in the world. These studies help to understand the exposure of populations to the virus to take actions to reduce the impact of SARS-CoV-2 infection. Objetive: To determine the anti-SARS-CoV-2 seroprevalence in migrants with a vocation for permanence in Bucaramanga and to identify factors associated with previous SARS-CoV-2 infection. Materials and Methods:Analytical cross-sectional study using consecutive sampling, which included adult migrants in Bucaramanga in February 2021. Surveys were conducted, and chemiluminescent immunoassays were performed to detect IgM and IgG antibodies to SARS-CoV-2 in serum samples. Prevalence ratios (PR) were estimated using a log-binomial regression model. Results:The study enrolled 462 participants. IgM seroprevalence was 11.7% (95% CI 9.1­14.9), IgG seroprevalence was 32.9% (95% CI 28.8­37.3), and IgM or IgG seroprevalence was 36.1% (95% CI 31.9­40.6). Contact with a confirmed case of COVID-19 (PR:1.54; 95% CI 1.04-2.29) or suspected case (PR:1.56; 95% CI 1.13­2.16); living with six or more people (PR: 1.52; 95% CI 1.05­2.20); stay in Colombia ≥ 2 years (PR:1.43; 95% CI 1.11­1.92), and presence of symptoms (PR:1.62; 95%CI 1.26­2.10) were some factors associated with higher IgG seroprevalence. Discussion: In Bucaramanga, SARS-CoV-2 seroprevalence among migrants was similar to the seroprevalences of migrants in Kuwait but lower than migrants in Paris and Singapore. Conclusions: The anti-SARS-CoV-2 seroprevalence among migrants with a vocation for permanence was similar to that reported among residents of Bucaramanga. Contact with suspected or confirmed COVID-19 cases and crowded conditions were some of the factors associated with seroprevalence.

Introdução: Existem poucos relatos que avaliam a soroprevalência contra SARS-CoV-2 na população migrante no mundo. Esses estudos ajudam a conhecer a exposição ao vírus nas populações para implementar ações que reduzam o impacto da infecção por SARS-CoV-2. Objetivo: Determinar a soroprevalência contra SARS CoV-2 em migrantes que pretendem permanecer em Bucaramanga e identificar fatores associados à infecção anterior por SARS-CoV-2. Materiais e Métodos: Estudo analítico transversal com amostragem consecutiva. Foram incluídos migrantes adultos em Bucaramanga durante fevereiro/2021. Foram realizados levantamentos e imunoensaios de quimioluminescência para IgM e IgG contra SARS-CoV-2 no soro. As razões de prevalência (RP) foram calculadas com regressão log-binomial. Resultados: foram incluídos 462 participantes. A soroprevalência de IgM foi de 11,7% (IC 95% 9,1-14,9), de IgG foi de 32,9% (IC 95% 28,8-37,3) e de IgM ou IgG foi de 36,1% (IC95% 31,9-40,6). Exposição a um caso confirmado (RP: 1,54; IC 95% 1,04-2,29) ou caso suspeito (RP: 1,56; IC 95% 1,13-2,16) de COVID-19, seis ou mais coabitantes (RP: 1,52; IC 95% 1,05 -2,20), permanência na Colômbia ≥2 anos (RP: 1,43; IC 95% 1,11-1,92) e presença de sintomas (RP: 1,62; IC95%1,26 - 2,10) foram associados a maior soroprevalência de IgG. Discussão: Em Bucaramanga, a soroprevalência em migrantes foi semelhante à de migrantes no Kuwait, mas menor do que em Paris e Cingapura. Conclusão: Em migrantes com vocação de permanência, a soroprevalência contra SARS-CoV-2 foi semelhante à relatada em residentes de Bucaramanga. O contato com casos suspeitos/confirmados de COVID-19 e as condições de superlotação foram alguns dos fatores associados à soroprevalência.

Chikungunya, Zika and Dengue seroprevalence rates among pregnant women in a hospital of southeastern Brazil / Soroprevalência de chikungunya, zika e dengue em gestantes de um hospital do sudeste do Brasil / Seroprevalencia de chikungunya, zika y dengue en mujeres embarazadas en un hospital del sureste de Brasil

Background and objectives: For decades, dengue outbreaks have been affecting vast territories of the Americas. In 2010's decade, Chikungunya and Zika virus (CHIKV and ZIKV) emerged as new arboviruses in the region. While several seroprevalence rates have been reported for dengue virus (DENV) infection in Brazil, serological surveys for the latest are scarce. We aimed to evaluate the seroprevalence of CHIKV, ZIKV, and DENV infections in pregnant women at admission to a public maternity hospital of Nova Iguaçu, state of Rio de Janeiro. Methods: A simple questionnaire was applied, containing limited demographic, obstetric, and clinical data, alongside with blood collection. Different commercial test kits, based on enzyme-linked immunosorbent assay (ELISA), were used. Results: Among 349 pregnant women enrolled from July to December 2017, there was a 28.4% seroreactivity for CHIKV, 47.2% for ZIKV, and 88.8% for DENV. Conclusion: These findings reflect the high dengue endemicity scenario and suggest a significant reach of the recent outbreaks of ZIKV and CHIKV infections in the region.(AU)

Justificativas e objetivos: Há décadas, surtos de dengue afetam vastos territórios das Américas. Na década de 2010, os vírus Chikungunya e Zika (CHIKV e ZIKV) surgiram como arbovírus emergentes na região. Embora diversas taxas de soroprevalência tenham sido relatadas para a infecção pelo vírus da dengue (DENV) no Brasil, pesquisas sorológicas para chikungunya e zika são escassas. Objetivou-se avaliar a soroprevalência das infecções por CHIKV, ZIKV e DENV em gestantes admitidas em uma maternidade pública de Nova Iguaçu, estado do Rio de Janeiro. Métodos: Foi aplicado um questionário simples, contendo dados demográficos, obstétricos e clínicos limitados, sendo realizada coleta de sangue na mesma visita. Diferentes kits de teste comerciais, baseados em ensaio imunoenzimático (ELISA), foram utilizados. Resultados: De 349 gestantes recrutadas de julho a dezembro de 2017, houve sororreatividade de 28,4% para CHIKV, 47,2% para ZIKV e 88,8% para DENV. Conclusão: Esses achados refletem o cenário de alta endemicidade da dengue e sugerem um alcance significativo dos surtos recentes causados por ZIKV e CHIKV na região.(AU)

Justificación y objetivos: Durante décadas, los brotes de dengue han afectado a vastos territorios de las Américas. En la década de 2010, los virus Chikungunya y Zika (CHIKV y ZIKV) surgieron como arbovirus emergentes en la región. Aunque se han reportadas varias tasas de seroprevalencia para la infección por el virus del dengue (DENV) en Brasil, la investigación serológica para el chikungunya y el Zika es escasa. Este estudio tuvo como objetivo evaluar la seroprevalencia de infecciones por CHIKV, ZIKV y DENV en mujeres embarazadas ingresadas en una maternidad pública en Nova Iguaçu, estado de Rio de Janeiro. Métodos: Se aplicó un sencillo cuestionario, que contenía datos demográficos, obstétricos y clínicos limitados, y se extrajo sangre en la misma visita. Se utilizaron diferentes kits de prueba comerciales basados en el ensayo inmunoabsorbente ligado a enzimas (ELISA). Resultados: De 349 mujeres embarazadas reclutadas de julio a diciembre de 2017, hubo serorreactividad de 28,4% para CHIKV, 47,2% para ZIKV y 88,8% para DENV. Conclusión: Estos hallazgos reflejan el escenario de alta endemicidad para el dengue y sugieren una variedad significativa de brotes recientes causados por ZIKV y CHIKV en la región.(AU)

SARS-CoV-2 in eight municipalities of the Colombian tropics: high immunity, clinical and sociodemographic outcomes.

BACKGROUND: Serological evaluation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an alternative that allows us to determine the prevalence and dynamics of this infection in populations. The goal of this study was to determine the clinical and sociodemographic dynamics of SARS-CoV-2 infection in a region of the Colombian Caribbean. METHODS: Between July and November 2020, a cross-sectional observational study was carried out in Córdoba, located in northeast Colombia in the Caribbean area. Eight municipalities with the largest populations were chosen and 2564 blood samples were taken. A commercial enzyme-linked immunosorbent assay was used with the recombinant protein antigen N of SARS-CoV-2. The people included in the study were asked for sociodemographic and clinical data, which were analysed by statistical methods. RESULTS: A seroprevalence of 40.8% was obtained for SARS-CoV-2 in the Córdoba region. In the bivariate analysis, no differences were observed in seropositivity against SARS-CoV-2 for gender or age range (p>0.05). Higher seropositivity was found in low socio-economic status and symptomatic patients (p<0.0001). A total of 30.7% of the asymptomatic patients were seropositive for SARS-CoV-2, which could be linked to the spread of this infection. In the multivariate analysis, seroconversion was related to poverty and clinical manifestations such as anosmia and ageusia (p<0.05). CONCLUSIONS: The high seropositivity in Córdoba is due to widespread SARS-CoV-2 in this population. The relationship between seropositivity and socio-economic status suggests a higher exposure risk to the virus caused by informal economic activities in low-income groups. Clinical manifestations such as anosmia and ageusia could be clinical predictors of infection by the new emergent coronavirus.

Seroprevalencia de infección reciente por dengue en una zona de riesgo

RESUMEN Introducción: El dengue se ha convertido en una de las enfermedades de mayor impacto epidemiológico, social y económico a nivel mundial. Objetivo: Estimar la prevalencia de la infección reciente por dengue en una zona de riesgo. Métodos: Estudio de corte transversal realizado en la Isla de la Juventud, Cuba, en el período comprendido entre julio y septiembre de 2021. Para el estudio epidemiológico se escogieron 12 manzanas, 57 viviendas y 2 participantes por cada una. Para la determinación serológica se utilizó el diagnosticador Umelisa Dengue IgM plus. Se calcularon frecuencias absolutas y relativas, prueba de chi-cuadrada e intervalos de confianza. Se mapificó análisis de focalidad en el radio de acción, así como los casos seropositivos. Se estimó la densidad demográfica y se tuvieron en cuenta variables de temperatura y precipitaciones. Resultados: Se estudiaron 106 individuos y se detectó una seroprevalencia de 10,3 % (IC95%: 5,29-17,81). El sexo femenino tuvo mayor prevalencia (14,7 %) (IC95%: 7,28-25,39); así como los mayores de 60 años 11,9 % (IC95%: 3,98-25,63). Se encontró relación significativa entre la seroprevalencia y el sexo. Se geolocalizaron 11 casos seropositivos donde la presencia del vector quedó documentada. Las temperaturas medias resultaron similares en los tres meses abordados, mientras que las precipitaciones fueron superiores en el mes de agosto. La focalidad marcó una tendencia al incremento, con su mayor pico en el mes de septiembre. Conclusiones: La seroprevalencia de la infección por dengue en la Isla de la Juventud, en el período analizado es alta y se asocia con el sexo.

ABSTRACT Introduction: Dengue has become one of the diseases with the greatest epidemiological, social and financial impact worldwide. Objective: To estimate the prevalence of recent dengue infection in a risk area. Methods: A cross-sectional study conducted between July and September 2021 on the Isle of Youth, Cuba. 12 blocks, 57 houses and 2 residents per house were selected for the epidemiological study. The UMELISA Dengue IgM Plus Kit was used for the serological determination. Absolute and relative frequencies, chi-square test and confidence interval were calculated. The seropositive cases and the analysis of the positive breeding sites in the radius of action were mapped. Population density was estimated and temperature and rainfall variables were taken into account. Results: A total of 106 individuals were studied and a seroprevalence of 10.3% (95% CI, 5.29-17.81) was found. Females had a higher prevalence rate (14.7%) (95% CI, 7.28-25.39), as well as individuals aged over 60 years (11.9%) (95% CI, 3.98-25.63). A significant association was identified between seroprevalence and sex. Eleven positive cases were mapped and the presence of the vector was documented. Average temperature was similar over the three months under study, while rainfall was higher in August. Positive breeding sites tended to increase with a higher peak in September. Conclusions: Seroprevalence of dengue infection on the Isle of Youth in the period under study is high and is associated with the sex.