Juan José López Amador

Association between pentavalent rotavirus vaccine and severe rotavirus diarrhea among children in Nicaragua.

CONTEXT Pentavalent rotavirus vaccine (RV5), a live, oral attenuated vaccine, prevented 98% of severe rotavirus diarrhea in a trial conducted mainly in Finland and the United States. Nicaragua introduced RV5 in 2006, providing the first opportunity to assess the association between vaccination and rotavirus disease in a developing country. OBJECTIVE To assess the association between RV5 vaccination and subsequent rotavirus diarrhea requiring overnight admission or intravenous hydration. DESIGN, SETTING, AND PARTICIPANTS Case-control evaluation in 4 hospitals in Nicaragua from June 2007 to June 2008. Cases were children age-eligible to receive RV5 who were admitted or required intravenous hydration for laboratory-confirmed rotavirus diarrhea. For each case (n = 285), 1 to 3 neighborhood (n = 840) and hospital (n = 690) controls were selected. MAIN OUTCOME MEASURES Primary outcome was the association of RV5 and rotavirus diarrhea requiring overnight admission or intravenous hydration in the emergency department. Secondary analysis further classified disease as severe and very severe. We computed the matched odds ratio of vaccination in cases vs controls. Vaccine effectiveness was estimated using the formula 1 - matched odds ratio x 100%. RESULTS Of the 285 rotavirus cases, 265 (93%) required hospitalization; 251 (88%) received intravenous hydration. A single rotavirus strain (G2P[4]) was identified in 88% of the cases. Among cases and controls, respectively, 18% and 12% were unvaccinated, 12% and 15% received 1 dose of RV5, 15% and 17% received 2 doses, and 55% and 57% received 3 doses. Vaccination with 3 doses was associated with a lower risk of rotavirus diarrhea requiring overnight admission or intravenous hydration (odds ratio [OR], 0.54; 95% confidence interval [CI], 0.36-0.82). Of the 285 rotavirus cases, 191 (67%) were severe and 54 (19%) were very severe. A progressively lower risk of severe (OR, 0.42; 95% CI, 0.26-0.70) and very severe rotavirus diarrhea (OR, 0.23; 95% CI, 0.08-0.61) was observed after RV5 vaccination. Thus, effectiveness of 3 doses of RV5 against rotavirus disease requiring admission or treatment with intravenous hydration was 46% (95% CI, 18%-64%); against severe rotavirus diarrhea, 58% (95% CI, 30%-74%); and against very severe rotavirus diarrhea, 77% (95% CI, 39%-92%). CONCLUSION Vaccination with RV5 was associated with a lower risk of severe rotavirus diarrhea in children younger than 2 years in Nicaragua but to a lesser extent than that seen in clinical trials in industrialized countries.

High seroprevalence of antibodies against dengue virus in a prospective study of schoolchildren in Managua, Nicaragua

To investigate the incidence of dengue virus (DENV) infection in Nicaragua, a 2‐year prospective study was conducted in schoolchildren 4–16 years old in the capital city of Managua. Blood samples were collected before the rainy season in 2001, 2002 and 2003, and were assayed for DENV‐specific antibodies. Participants were monitored for dengue‐like illness, and acute and convalescent blood samples were collected from suspected dengue cases. In 2001 and 2002, 602 and 397 students were recruited, respectively, and paired annual serum samples were available from 467 and 719 participants in 2001–2002 and 2002–2003, respectively. The overall seroprevalence of anti‐DENV antibodies was 91%, increasing from 75% at age 4 to 100% at age 16. The incidence of DENV infection was 12% in Year 1 and 6% in Year 2 (P < 0.001). During Year 1, four laboratory‐confirmed dengue cases were detected, with one DENV2 isolate; during Year 2, there were six confirmed dengue cases, with one DENV1 isolate. These and additional circulating serotypes were confirmed by plaque reduction neutralisation test. This study demonstrates surprisingly high transmission of DENV in urban Nicaragua.

Uptake of Rotavirus Vaccine and National Trends of Acute Gastroenteritis among Children in Nicaragua

BACKGROUND In October 2006, a new rotavirus vaccine was introduced in Nicaragua and was available free to all age-eligible children. We assessed vaccine uptake and trends in acute gastroenteritis (AGE) to assess vaccine impact. METHODS We analyzed national data from the period 2001-2007 on the total number of AGE episodes and on RotaTeq vaccine dose administration during 2006-2007. RESULTS After the introduction of RotaTeq, 1-dose vaccine coverage rates rapidly increased to 80% among age-eligible children. During the 2007 rotavirus season, when combined 2- and 3-dose vaccine coverage among children aged 0-11 months was approximately 26%, the total number of AGE episodes among children aged 0-11 months decreased by 23%, compared with a decrease of 6% among unvaccinated children aged 12-59 months. Furthermore, a 12% decrease in the number of all-cause hospitalizations for AGE was noted among children aged 0-11 months, whereas a approximately 5% increase was observed among children aged 12-59 months. CONCLUSIONS The high rate of vaccination among age-eligible children soon after vaccine introduction in Nicaragua indicates an efficient immunization program. However, in the age group at risk of rotavirus disease, vaccine coverage during the 2007 rotavirus season had yet to reach a level sufficient for making firm conclusions about vaccine impact. Epidemiologic studies to evaluate vaccine effectiveness and ongoing surveillance as vaccine uptake increases will allow a better assessment of vaccine impact.

Fluid Intake and Decreased Risk for Hospitalization for Dengue Fever, Nicaragua

In a hospital and health center-based study in Nicaragua, fluid intake during the 24 hours before being seen by a clinician was statistically associated with decreased risk for hospitalization of dengue fever patients. Similar results were obtained for children <15 years of age and older adolescents and adults in independent analyses.

Rotavirus disease burden, Nicaragua 2001–2005: defining the potential impact of a rotavirus vaccination program

BACKGROUND In October 2006, a rotavirus vaccine was introduced in Nicaragua for routine immunization of all children. We document the baseline diarrheal disease burden in Nicaragua prior to the vaccine program to facilitate future studies to measure vaccine impact. METHODS We analyzed national data for 2001-2005 on total acute gastroenteritis healthcare visits, hospitalizations, and mortality in Nicaraguan children aged <5 years. RESULTS Prior to vaccine introduction, by age 5 years, one in four Nicaraguan children required an outpatient consultation, one in 34 were hospitalized, and one in 2487 died from rotavirus-associated diarrhea, representing approximately 41,122 outpatient visits, 4460 hospitalizations, and 60 deaths per year that are preventable through vaccination. Almost half of the total acute gastroenteritis burden was in children <1 year of age. Two distinct seasonal peaks were noted in acute gastroenteritis hospitalizations and deaths. CONCLUSIONS Existing data sources on all-cause acute gastroenteritis could be useful for establishing diarrhea disease burden and monitoring trends after vaccine introduction. Blunting of winter season peaks in rates of diarrhea, particularly among children aged <1-2 years, would be a useful indicator of impact from rotavirus vaccination.

Outbreak of rotavirus gastroenteritis with high mortality, Nicaragua, 2005

OBJECTIVES We investigated a nationwide outbreak of severe rotavirus gastroenteritis in Nicaragua in children under 5 years old, leading to many consultations, hospitalizations, and deaths. We questioned whether a vaccine might have prevented these illnesses and deaths, sought to identify risk factors for death, and developed a clinical profile of children hospitalized with diarrhea. METHODS We conducted a case-control study to determine whether children who died had access to routine immunizations, a proxy predicting access to a rotavirus vaccine. We identified risk factors for death among children who died in the outbreak compared with surviving age-matched controls with diarrhea. We collected stools, clinical data, and immunization data on children hospitalized for diarrhea to test for rotavirus, develop the profile, and forecast future access to a rotavirus vaccine. RESULTS The outbreak from February to April 2005 caused 47 470 consultations and 52 deaths. Approximately 80% of cases and controls and 60% of children hospitalized with diarrhea had access to routine immunizations and would likely have had access to a rotavirus vaccine. With a vaccine efficacy of 85%, up to 51% of severe rotavirus cases and up to 68% of deaths could have been prevented if a rotavirus vaccine were available as part of routine childhood immunizations. Study of 35 case-control pairs indicated that severe illnesses, malnutrition, and care by traditional healers were risk factors for death. Rotavirus was found in 42% of samples from hospitalized children and was associated with severe disease and dehydration. CONCLUSIONS The impact of the seasonal outbreaks of rotavirus disease could be diminished with a rotavirus vaccine, improvements in oral rehydration programs, and training of traditional healers in the proper management of children with acute diarrhea.

Cost analysis of centralized viral load testing for antiretroviral therapy monitoring in Nicaragua, a low-HIV prevalence, low-resource setting.

BackgroundHIV viral load testing as a component of antiretroviral therapy monitoring is costly. Understanding the full costs and the major sources of inefficiency associated with viral load testing is critical for optimizing the systems and technologies that support the testing process. The objective of our study was to estimate the costs associated with viral load testing performed for antiretroviral therapy monitoring to both patients and the public healthcare system in a low-HIV prevalence, low-resource country.MethodsA detailed cost analysis was performed to understand the costs involved in each step of performing a viral load test in Nicaragua, from initial specimen collection to communication of the test results to each patients healthcare provider. Data were compiled and cross referenced from multiple information sources: laboratory records, regional surveillance centre records, and scheduled interviews with the key healthcare providers responsible for HIV patient care in five regions of the country.ResultsThe total average cost of performing a viral load test in Nicaragua varied by region, ranging from US

Paralytic shellfish poisonings resulting from an algal bloom in Nicaragua

99.01 to US

Management of the HIV epidemic in Nicaragua: the need to improve information systems and access to affordable diagnostics

124.58, the majority of which was at the laboratory level:

CLINICAL, EPIDEMIOLOGIC, AND VIROLOGIC FEATURES OF DENGUE IN THE 1998 EPIDEMIC IN NICARAGUA

88.73 to