Low detection rate of RT-PCR-confirmed COVID-19 using IgM/IgG rapid antibody tests in a large community sample in Lima, Peru.

BACKGROUND: Rapid IgM/IgG antibody tests were largely used in lieu of RT-PCR tests as part of COVID-19 public health response activities in Lima, Peru. To assess their utility, we explored the relationship between the time since onset of several COVID-19-related symptoms and the sensitivity of a rapid combined IgM/IgG antibody test. METHODS: We collected data from a community sample of individuals (n = 492) who received concurrent RT-PCR and rapid IgM/IgG antibody testing between May 2020 and March 2021. We estimated the sensitivity of the antibody test, against the RT-PCR test, by weeks since symptom onset via segmented regression analysis. RESULTS: The overall sensitivity of the rapid IgM/IgG antibody test was 46.7% (95% CI, 42.4-51.2%). Among 372 (75.6%) participants who reported COVID-19-related symptoms, sensitivity increased from 30.4% (95% CI, 24.7-36.6%) in week 1 after symptom onset to 83.3% (95% CI, 41.6-98.4%) in week 4. The test sensitivity increased by 31.9% (95% CI, 24.8-39.0%) per week until week 2 to 3, then decreased by - 6.0% (95% CI, - 25.7-13.7%) per week thereafter. CONCLUSION: Rapid antibody tests are a poor substitute for RT-PCR testing, regardless of presenting symptoms. This highlights the need for future pandemic planning to include timely and equitable access to gold-standard diagnostics, treatment, and vaccination.

Prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 Antibodies Among Market and City Bus Depot Workers in Lima, Peru.

We report severe acute respiratory syndrome coronavirus 2 antibody positivity among market and city bus depot workers in Lima, Peru. Among 1285 vendors from 8 markets, prevalence ranged from 27% to 73%. Among 488 workers from 3 city bus depots, prevalence ranged from 11% to 47%. Self-reported symptoms were infrequent.

Neurocysticercosis as a cause of epilepsy and seizures in two community-based studies in a cysticercosis-endemic region in Peru.

BACKGROUND: The prevalence of epilepsy added to inadequate treatment results in chronic morbidity and considerable mortality in poor populations. Neurocysticercosis (NCC), a helminthic disease of the central nervous system, is a leading cause of seizures and epilepsy in most of the world. METHODS: Taking advantage of a cysticercosis elimination program, we performed two community-based cross-sectional studies between 2006 and 2007 in 58 rural communities (population 20,610) to assess the prevalence and characteristics of epilepsy and epileptic seizures in this endemic region. Serological and computed tomography (CT) data in individuals with epilepsy were compared to previous surveys in general population from the same region. PRINCIPAL FINDINGS: In two surveys, 17,450 individuals were evaluated. Lifetime prevalence of epilepsy was 17.25/1000, and prevalence of active epilepsy was 10.8/1000 inhabitants. The prevalence of epilepsy increased after age 25 years and dropped after age 45. Only 24% (45/188) of patients with active epilepsy were taking antiepileptic drugs, all at sub-therapeutic doses. Antibodies to cysticercosis were found in approximately 40% of individuals with epilepsy in both studies. In one survey only individuals presenting strong antibody reactions were significantly associated with having epilepsy (OR 5.74; p<0.001). In the second, the seroprevalence as well as the proportion presenting strong antibody reactions were both significantly higher in individuals with epilepsy (OR 2.2 and 4.33, respectively). Brain CT showed NCC-compatible images in 109/282 individuals with epilepsy (39%). All individuals with viable parasites on CT were seropositive. CONCLUSION: The prevalence of epilepsy in this cysticercosis endemic region is high and NCC is an important contributor to it.

Prevalencia de anticuerpos anti-Toxoplasma gondii en gestantes del Hospital Cayetano Heredia (Lima) / Prevalence of antibodies anti-toxoplasma gondii in gestantes of the Hospital Cayetano Heredia (Lima)

Introducción: La toxoplasmosis es una zoonosis de etiología parasitaria ampliamente distribuída a nivel mundial, que adquiere importancia cuando la infección ocurre durante la gestación; por lo que es importante conocer la prevalencia de anticuerpos IgG e IgM anti-toxoplasma en esta población. Matarial y Métodos: el presente es un estudio prospectivo, en el se incluyeron 122 gestantes del Hospital Nacional Cayetano Heredia, y se recolectaron datos generales y epidemiológicos, así como una muestra de sangre venosa; en la cual se determinó anticuerpos IgG e IgM Anti-toxoplasma utilizando el método de Inmunofluorescencia Indirecta (IFI). Resultados: La media de la edad fue de 25.72 +- 6.28 años. Fueron seropositivas para IgG y/o IgM el 58.9 por ciento (71); para IgG el 54,9 por ciento (66) y para Igm el 4,9 por ciento (6) de gestantes. Un 4,6 por ciento tuvo sospecha de infección aguda. No se encontró asociación entre seropositividad y los datos epidemiológicos analizados. Conclusiones: Se evidenció que la presencia de anticuerpos anti-Toxoplasma gondii es frecuente en la población de gestantes, sin embargo hay una elevada proporción de gestantes (cerca al 40 por ciento) susceptibles a adquirir la infección durante la gestación. Estos hallazgos ameritan una mayor investigación con respecto a la prevalencia e incidencia de la infección por toxoplasma gondii durante la gestación para sí planificar programas de prevención.

Curso salud colectiva: módulo II: epidemiología / Collective health course: module II: epidemiology

Dividido en 7 unidades. Unidad 1: epidemiología: concepto y contribución en la gestión de servicios de salud; Unidad 2: cambios poblacionales: transición epidemiológica; Unidad 3: priorización de problemas de salud: indicadores de magnitud, letalidad, causalidad y factores de riesgo; Unidad 4: fuentes de información; Unidad 5: nociones básicas de estadística; Unidad 6: vigilancia epidemiológica; Unidad 7: epidemiología de los servicios de salud