Using Regional Sero-Epidemiology SARS-CoV-2 Anti-S Antibodies in the Dominican Republic to Inform Targeted Public Health Response.

Incidence of COVID-19 has been associated with sociodemographic factors. We investigated variations in SARS-CoV-2 seroprevalence at sub-national levels in the Dominican Republic and assessed potential factors influencing variation in regional-level seroprevalence. Data were collected in a three-stage cross-sectional national serosurvey from June to October 2021. Seroprevalence of antibodies against the SARS-CoV-2 spike protein (anti-S) was estimated and adjusted for selection probability, age, and sex. Multilevel logistic regression was used to estimate the effect of covariates on seropositivity for anti-S and correlates of 80% protection (PT80) against symptomatic infection for the ancestral and Delta strains. A total of 6683 participants from 134 clusters in all 10 regions were enrolled. Anti-S, PT80 for the ancestral and Delta strains odds ratio varied across regions, Enriquillo presented significant higher odds for all outcomes compared with Yuma. Compared to being unvaccinated, receiving ≥2 doses of COVID-19 vaccine was associated with a significantly higher odds of anti-S positivity (OR 85.94, [10.95-674.33]) and PT80 for the ancestral (OR 4.78, [2.15-10.62]) and Delta strains (OR 3.08, [1.57-9.65]) nationally and also for each region. Our results can help inform regional-level public health response, such as strategies to increase vaccination coverage in areas with low population immunity against currently circulating strains.

Monitoring Temporal Changes in SARS-CoV-2 Spike Antibody Levels and Variant-Specific Risk for Infection, Dominican Republic, March 2021-August 2022.

To assess changes in SARS-CoV-2 spike binding antibody prevalence in the Dominican Republic and implications for immunologic protection against variants of concern, we prospectively enrolled 2,300 patients with undifferentiated febrile illnesses in a study during March 2021-August 2022. We tested serum samples for spike antibodies and tested nasopharyngeal samples for acute SARS-CoV-2 infection using a reverse transcription PCR nucleic acid amplification test. Geometric mean spike antibody titers increased from 6.6 (95% CI 5.1-8.7) binding antibody units (BAU)/mL during March-June 2021 to 1,332 (95% CI 1,055-1,682) BAU/mL during May-August 2022. Multivariable binomial odds ratios for acute infection were 0.55 (95% CI 0.40-0.74), 0.38 (95% CI 0.27-0.55), and 0.27 (95% CI 0.18-0.40) for the second, third, and fourth versus the first anti-spike quartile; findings were similar by viral strain. Combining serologic and virologic screening might enable monitoring of discrete population immunologic markers and their implications for emergent variant transmission.

SARS-CoV-2 seroprevalence, cumulative infections, and immunity to symptomatic infection - A multistage national household survey and modelling study, Dominican Republic, June-October 2021.

Background: Population-level SARS-CoV-2 immunological protection is poorly understood but can guide vaccination and non-pharmaceutical intervention priorities. Our objective was to characterise cumulative infections and immunological protection in the Dominican Republic. Methods: Household members ≥5 years were enrolled in a three-stage national household cluster serosurvey in the Dominican Republic. We measured pan-immunoglobulin antibodies against the SARS-CoV-2 spike (anti-S) and nucleocapsid glycoproteins, and pseudovirus neutralising activity against the ancestral and B.1.617.2 (Delta) strains. Seroprevalence and cumulative prior infections were weighted and adjusted for assay performance and seroreversion. Binary classification machine learning methods and pseudovirus neutralising correlates of protection were used to estimate 50% and 80% protection against symptomatic infection. Findings: Between 30 Jun and 12 Oct 2021 we enrolled 6683 individuals from 3832 households. We estimate that 85.0% (CI 82.1-88.0) of the ≥5 years population had been immunologically exposed and 77.5% (CI 71.3-83) had been previously infected. Protective immunity sufficient to provide at least 50% protection against symptomatic SARS-CoV-2 infection was estimated in 78.1% (CI 74.3-82) and 66.3% (CI 62.8-70) of the population for the ancestral and Delta strains respectively. Younger (5-14 years, OR 0.47 [CI 0.36-0.61]) and older (≥75-years, 0.40 [CI 0.28-0.56]) age, working outdoors (0.53 [0.39-0.73]), smoking (0.66 [0.52-0.84]), urban setting (1.30 [1.14-1.49]), and three vs no vaccine doses (18.41 [10.69-35.04]) were associated with 50% protection against the ancestral strain. Interpretation: Cumulative infections substantially exceeded prior estimates and overall immunological exposure was high. After controlling for confounders, markedly lower immunological protection was observed to the ancestral and Delta strains across certain subgroups, findings that can guide public health interventions and may be generalisable to other settings and viral strains. Funding: This study was funded by the US CDC.

Improved tools and strategies for the prevention and control of arboviral diseases: A research-to-policy forum.

BACKGROUND: Research has been conducted on interventions to control dengue transmission and respond to outbreaks. A summary of the available evidence will help inform disease control policy decisions and research directions, both for dengue and, more broadly, for all Aedes-borne arboviral diseases. METHOD: A research-to-policy forum was convened by TDR, the Special Programme for Research and Training in Tropical Diseases, with researchers and representatives from ministries of health, in order to review research findings and discuss their implications for policy and research. RESULTS: The participants reviewed findings of research supported by TDR and others. Surveillance and early outbreak warning. Systematic reviews and country studies identify the critical characteristics that an alert system should have to document trends reliably and trigger timely responses (i.e., early enough to prevent the epidemic spread of the virus) to dengue outbreaks. A range of variables that, according to the literature, either indicate risk of forthcoming dengue transmission or predict dengue outbreaks were tested and some of them could be successfully applied in an Early Warning and Response System (EWARS). Entomological surveillance and vector management. A summary of the published literature shows that controlling Aedes vectors requires complex interventions and points to the need for more rigorous, standardised study designs, with disease reduction as the primary outcome to be measured. House screening and targeted vector interventions are promising vector management approaches. Sampling vector populations, both for surveillance purposes and evaluation of control activities, is usually conducted in an unsystematic way, limiting the potentials of entomological surveillance for outbreak prediction. Combining outbreak alert and improved approaches of vector management will help to overcome the present uncertainties about major risk groups or areas where outbreak response should be initiated and where resources for vector management should be allocated during the interepidemic period. CONCLUSIONS: The Forum concluded that the evidence collected can inform policy decisions, but also that important research gaps have yet to be filled.

Chikungunya en la República Dominicana: lecciones aprendidas en los primeros seis meses / Chikungunya in the Dominican Republic: lessons learned in the first six months

La epidemia de chikungunya en la República Dominicana se inició en febrero de 2014. En los primeros seis meses se registraron 429 421 casos, que representaron 65% de todos los notificados a la Organización Panamericana de la Salud por 33 países y territorios de la Región de las Américas. Esta epidemia se ha transmitido con rapidez en dicho país y ha demandado una intensa respuesta intersectorial, que ha liderado el Ministerio de Salud Pública y, especialmente, el Sistema Nacional de Vigilancia Epidemiológica y la red de los servicios de salud. Considerando que afectará a miles de personas, el objetivo de este artículo es describir las actuaciones realizadas y compartir los resultados y las lecciones aprendidas durante estos primeros meses con los ministerios de salud y los profesionales de los países de la Región para ayudarles a preparar una respuesta adecuada para afrontarla de forma efectiva y eficiente.

The chikungunya epidemic in the Dominican Republic began in February 2014. During the first six months 429 421 cases were recorded, representing 65% of all those notified to the Pan American Health Organization by 33 countries and territories of the Region of the Americas. This epidemic has spread quickly in the Dominican Republic, requiring a focused intersectoral response, led by the Ministry of Public Health and involving major efforts by the National Epidemiological System and the health services network. Given that the virus will affect thousands of people, this article seeks to describe the actions that have already been carried out, and to share the results and lessons learned during these first months with health ministries and professionals in the countries of the Region, in order to assist them to prepare an appropriate response to confront the epidemic effectively and efficiently.

[Chikungunya in the Dominican Republic: lessons learned in the first six months]. / Chikungunya en la República Dominicana: lecciones aprendidas en los primeros seis meses.

The chikungunya epidemic in the Dominican Republic began in February 2014. During the first six months 429 421 cases were recorded, representing 65% of all those notified to the Pan American Health Organization by 33 countries and territories of the Region of the Americas. This epidemic has spread quickly in the Dominican Republic, requiring a focused intersectoral response, led by the Ministry of Public Health and involving major efforts by the National Epidemiological System and the health services network. Given that the virus will affect thousands of people, this article seeks to describe the actions that have already been carried out, and to share the results and lessons learned during these first months with health ministries and professionals in the countries of the Region, in order to assist them to prepare an appropriate response to confront the epidemic effectively and efficiently.

Dengue in the Dominican Republic: epidemiology for 2004.

The Dominican Republic (DR) has experienced tremendous increase in the number of cases of dengue virus (DENV) reported in the past few years. There are four serotypes of DENV (1-4), and each can cause classic dengue fever (DF), dengue hemorrhagic fever (DHF), or dengue shock syndrome (DSS). DENV-1-4 are currently circulating in the DR; however, the Department of Epidemiology of the Dominican Republic (DIEGPI) has been able to isolate only DENV-2 and DENV-4. In the DR, the development of DENV infection occurred primarily in the second semester of the year. Since the DR instituted a vigilant approach to dengue infections, there have been three major outbreaks detected: one in 1998, one in 2000, and one in 2002. DF is the clinical presentation most currently seen at clinics, accounting for about 75% of cases, while patients with DHF account for about 19% of cases seen. Currently, there are seven provinces in which the total number of dengue cases per 100,000 inhabitants is higher than 32. With a vigilant approach, the DR should continue to see success in controlling the DENV outbreak.

Transmisión de parásitos intestinales en grupos nativos de la amazonía: un estudio microepidemiológico / Intestinal diseases parasitic communicable at Amazon natives. A microepidemiology study

Se estudió una comunidad nativa de 60 habitantes que viven relativamente aislados en la selva Amazónica. Se hicieron análisis cuantitativos de heces (excreción de huevos de parásitos por persona), y se determinó la contaminación del medio ambiente por huevos de parásitos intestinales (Ascaris lumbricoides, Trichuris trichiura y Ancylostoma duodenale). El número promedio de huevos en las heces fue de 4220 huevos de Ascaris lumbricoides por cada gramo de heces. No se encontraron diferencias significativas en la intensidad de infección según edad, sexo o familia. El riesgo de infección parasitaria fue aproximadamente igual en toda la comunidad: cualquier persona del poblado corre el mismo riesgo de infección por el estilo comunitario de vida en grupo y sobre todo por la transmisión de los huevos por vía aérea en el polvo. Sin embargo, se encontró diferentes intensidades de contaminación, en las casas y en sus alrededores (promedio: 0-17 huevos de Asvaris lumbricoides por gramo de tierra). Se hizo un tratamiento masivo de toda la población con Mebendazol. Cinco meses después la población había logrado los niveles de prevalencia acusados antes del tratamiento, sólo la intensidad de infección había disminuido significativamente. Se concluye que la planificación de medidas higiénicas debe considerar toda la comunidad en conjunto.