Seroepidemiological trend of strongyloidiasis in the Bolivian Chaco (1987-2013) in the absence of disease-specific control measures.

OBJECTIVES: The prevalence of Strongyloides stercoralis infections is grossly underestimated because infections go mostly undetected, although they can persist for a lifetime due to the auto-infective cycle. In the Bolivian Chaco, the prevalence of soil-transmitted nematodes dropped dramatically in the past 25 years, but the mebendazole used for preventive chemotherapy has no effect on S. stercoralis. Meanwhile, the prevalence of intestinal protozoan infections remains unchanged. We compared S. stercoralis seroprevalence in rural communities of the Bolivian Chaco from 1987 to 2013. METHODS: Sera collected during two previous serosurveys, conducted in the Chaco region in 1987 and 2013, were tested for S. stercoralis using a commercial assay (Bordier-ELISA, Bordier Affinity Products, Switzerland). RESULTS: Overall, 355 sera were analysed, 122 from the 1987 survey and 233 from the 2013 survey. Seropositivity for S. stercoralis was significantly more prevalent in 1987 (19/122, 16% in 1987 vs. 15/233, 6% in 2013, P = 0.006), accounted for by a drop from 17% to 3% in people under 26 years of age. Multivariate analysis showed a significant association between seropositivity for S. stercoralis and age in the 2013 population (OR 1.03 for each one-year increase, 95%CI 1.00-1.05, P = 0.04), but none in 1987. CONCLUSIONS: The significant reduction in S. stercoralis seroprevalence in Bolivian Chaco cannot be explained by preventive chemotherapy or improved social-sanitary conditions. As the drop is seen in younger generations, it is consistent with little transmission occurring. However, the risk of transmission still exists, as prevalence is persistently high in older individuals, who present a potential reservoir due to the lifelong nature of S. stercoralis infections.

Diversity of picornaviruses in rural Bolivia.

The family Picornaviridae is a large and diverse group of viruses that infect humans and animals. Picornaviruses are among the most common infections of humans and cause a wide spectrum of acute human disease. This study began as an investigation of acute flaccid paralysis (AFP) in a small area of eastern Bolivia, where surveillance had identified a persistently high AFP rate in children. Stools were collected and diagnostic studies ruled out poliovirus. We tested stool specimens from 51 AFP cases and 34 healthy household or community contacts collected during 2002-2003 using real-time and semi-nested reverse transcription polymerase chain reaction assays for enterovirus, parechovirus, cardiovirus, kobuvirus, salivirus and cosavirus. Anecdotal reports suggested a temporal association with neurological disease in domestic pigs, so six porcine stools were also collected and tested with the same set of assays, with the addition of an assay for porcine teschovirus. A total of 126 picornaviruses were detected in 73 of 85 human individuals, consisting of 53 different picornavirus types encompassing five genera (all except Kobuvirus). All six porcine stools contained porcine and/or human picornaviruses. No single virus, or combination of viruses, specifically correlated with AFP; however, the study revealed a surprising complexity of enteric picornaviruses in a single community.

Putting safety first: ensuring safe vaccination practices during the 2006 rubella campaign in Bolivia.

Over 3 weeks in 2006, 3826083 persons were vaccinated against rubella during a national immunization campaign in Bolivia. This campaign was the largest mass immunization campaign ever conducted in the country. Therefore, in addition to strategic and micro-planning and financial and social mobilization, issues of safety (eg, safe injection practices and waste management) were at the forefront of campaign preparations. Waste management practices were promoted through guidelines, training, and implementation of locally appropriate solutions. These experiences show that, with detailed planning and preparation, in addition to collaboration among key partners, effective management of waste during campaigns in low-income countries is both feasible and beneficial. However, challenges remain in implementing environmentally appropriate solutions. This campaign served as the launching pad for a focus on ensuring that proper waste management practices are used both in the routine immunization program and in subsequent campaigns across Bolivia.

Cluster-sample surveys and lot quality assurance sampling to evaluate yellow fever immunisation coverage following a national campaign, Bolivia, 2007.

OBJECTIVE: To estimate the yellow fever (YF) vaccine coverage for the endemic and non-endemic areas of Bolivia and to determine whether selected districts had acceptable levels of coverage (>70%). METHODS: We conducted two surveys of 600 individuals (25 x 12 clusters) to estimate coverage in the endemic and non-endemic areas. We assessed 11 districts using lot quality assurance sampling (LQAS). The lot (district) sample was 35 individuals with six as decision value (alpha error 6% if true coverage 70%; beta error 6% if true coverage 90%). To increase feasibility, we divided the lots into five clusters of seven individuals; to investigate the effect of clustering, we calculated alpha and beta by conducting simulations where each cluster's true coverage was sampled from a normal distribution with a mean of 70% or 90% and standard deviations of 5% or 10%. RESULTS: Estimated coverage was 84.3% (95% CI: 78.9-89.7) in endemic areas, 86.8% (82.5-91.0) in non-endemic and 86.0% (82.8-89.1) nationally. LQAS showed that four lots had unacceptable coverage levels. In six lots, results were inconsistent with the estimated administrative coverage. The simulations suggested that the effect of clustering the lots is unlikely to have significantly increased the risk of making incorrect accept/reject decisions. CONCLUSIONS: Estimated YF coverage was high. Discrepancies between administrative coverage and LQAS results may be due to incorrect population data. Even allowing for clustering in LQAS, the statistical errors would remain low. Catch-up campaigns are recommended in districts with unacceptable coverage.

Rotavirus genotype distribution during the pre-vaccine period in Bolivia: 2007-2008.

OBJECTIVES: Rotavirus is the most important etiology of severe diarrhea in Bolivia. The monovalent attenuated human oral rotavirus vaccine Rotarix(®) was introduced in Bolivia in 2008. We describe the molecular epidemiology of circulating rotavirus strains before vaccine introduction. METHODS: Two thousand one hundred thirty-five diarrheal samples were collected from hospitals in four Bolivian cities during 2007-2008. Forty-three percent (445 of 1030 rotavirus-positive samples) were analyzed for G and P genotypes. Among those, 331 were electropherotyped by polyacrylamide gel electrophoresis. Disease severity was quantified using a modified Vesikari scale. RESULTS: Among the 445 samples, five genotypes were found to be prevalent: G9P[8] (33%), G1P[6] (17%), G2P[4] (13%), G9P[6] (12%), and G1P[8] (4%). Co-infections with two or more strains accounted for 14% of samples. The most prevalent strain, G9, showed greater electropherotype diversity compared to other serogroups. Strain G1P[6] generally infected younger children and peaked later in the year than other strains. No particular genotype was associated with a higher severity score, though there was a significant difference in the duration of diarrhea between genotypes. CONCLUSIONS: During the 2-year pre-vaccine period, substantial diversity of rotavirus co-circulating strains was observed. These data constitute a baseline against which changes in circulating strains post-vaccine introduction can be monitored.

Cost-effectiveness of rotavirus vaccination in Bolivia from the state perspective.

BACKGROUND: In Bolivia, in 2008, the under-five mortality rate is 54 per 1000 live births. Diarrhea causes 15% of these deaths, and 40% of pediatric diarrhea-related hospitalizations are caused by rotavirus illness (RI). Rotavirus vaccination (RV), subsidized by international donors, is expected to reduce morbidity, mortality, and economic burden to the Bolivian state. Estimates of illness and economic burden of RI and their reduction by RV are essential to the Bolivian state's policies on RV program financing. The goal of this report is to estimate the economic burden of RI and the cost-effectiveness of the RV program. METHODS: To assess treatment costs incurred by the healthcare system, we abstracted medical records from 287 inpatients and 6751 outpatients with acute diarrhea between 2005 and 2006 at 5 sentinel hospitals in 4 geographic regions. RI prevalence rates were estimated from 4 years of national hospital surveillance. We used a decision-analytic model to assess the potential cost-effectiveness of universal RV in Bolivia. RESULTS: Our model estimates that, in a 5-year birth cohort, Bolivia will incur over US$3 million in direct medical costs due to RI. RV reduces, by at least 60%, outpatient visits, hospitalizations, deaths, and total direct medical costs associated with rotavirus diarrhea. Further, RV was cost-savings below a price of US$3.81 per dose and cost-effective below a price of US$194.10 per dose. Diarrheal mortality and hospitalization inputs were the most important drivers of rotavirus vaccine cost-effectiveness. DISCUSSION: Our data will guide Bolivia's funding allocation for RV as international subsidies change.

Interruption of indigenous measles transmission in Bolivia since October 2000.

Measles incidence in Bolivia declined after the introduction of campaign strategies in the 1980s. From 1990 to 1993, the peak incidence of measles (59 cases/100,000 population) was in 1992. In 1994, after the goal of interruption of measles transmission was adopted, a national vaccination campaign targeting children <15 years old was conducted and achieved 96% coverage. During 1995-1997, cases declined, although routine coverage was <90% in most years. During 1998-2000, a nationwide epidemic occurred among 2567 case-patients, most of whom were unvaccinated. A national vaccination campaign, with strong supervision, was conducted during November and December 1999 and targeted areas with low coverage. Only 122 cases were confirmed in 2000, with the last confirmed case occurring in October. Crucial to the control of the outbreak were sufficient resources and political support, intensive local planning, door-to-door vaccination with strict supervision, and rapid house-to-house coverage monitoring that improved accountability at the local level and timely and thorough outbreak investigations.

A prefilled injection device for outreach tetanus immunization by Bolivian traditional birth attendants / Vacunación antitetánica extrainstitucional por parteras empíricas bolivianas mediante dispositivos desechables de una sola dosis

This study evaluated the performance, acceptability, and appropriateness of a new, single-use, prefilled injection device called UniJect™ for an outreach immunization application.6 Between April and June 1995, UniJect devices were used by 36 traditional birth attendants to administer tetanus toxoid injections to 2 240 pregnant women during routine, antenatal home visits in the Northern, Ichilos, and Warnes Districts of Santa Cruz, Bolivia. Because tetanus toxoid is relatively heat stable, the traditional birth attendants were able to keep the tetanus toxoid-filled UniJect devices in their homes for up to one month without refrigeration. The devices were stored, transported, and disposed of in an outreach carrier designed to reduce the risks of improper handling and disposal. Data were collected from injection recipients, traditional birth attendants, and supervisors via observation, questionnaires, and post-study interviews. The performance of the UniJect device and its acceptability among all groups was very high. The traditional birth attendants used UniJect properly and safely; there were no reports or observations of device misuse, reuse, or needle-stick. Advantages cited included the fact that the device required no assembly, offered assured sterility, and reduced vaccine wastage sometimes associated with multi-dose vials. The ability to store and transport the vaccine-filled devices without ice also greatly simplified logistics.

En este estudio se evaluaron el rendimiento, la aceptabilidad y la conveniencia de la inmunización antitetánica extrainstitucional con un nuevo dispositivo hipodérmico de una sola dosis, el UniJect®. De abril a junio de 1995, el dispositivo UniJect aprestado de fábrica con una sola dosis de toxoide tetánico fue utilizado por 36 parteras tradicionales para vacunar a 2 240 mujeres embarazadas durante las visitas domiciliarias prenatales de rutina en los distritos Norte, Ichilos y Warnes de Santa Cruz, Bolivia. Ya que el toxoide tetánico es termoestable, las parteras pudieron mantener los dispositivos UniJect sin refrigeración en sus hogares por un período de hasta un mes. Los UniJect se guardaron, transportaron y desecharon en portadores extrainstitucionales diseñados para reducir los riesgos de manipularlos y desecharlos de forma inadecuada. Se recolectaron datos de las mujeres vacunadas, las parteras tradicionales y sus supervisores, mediante observación, cuestionarios y entrevistas realizadas después del estudio. Todos los grupos consideraron muy satisfactorios el rendimiento y la aceptabilidad del dispositivo UniJect. Las parteras tradicionales lo usaron de forma apropiada y cuidadosa; no hubo informes ni observaciones de mala utilización, reúso o puntazos accidentales. Se mencionaron, como ventajas del dispositivo, que no requiere montaje, asegura la esterilidad y reduce el desperdicio de vacuna que a veces ocurre con las ampollas de dosis múltiples. Además, todo el procedimiento se simplifica porque los dispositivos pueden almacenarse y transportarse sin necesidad de hielo.

Manual de Bioseguridad / Manual on Biosafety

El manual tiene el objetivo facilitar la aplicación de las normas referentes a la bioseguridad aplicada a la administración de vacunas en los establecimientos de salud de Bolivia.

Propuesta de intervenciones y acciones inmediatas para el control del colera / Proposal of interventions and immediate actions for control of cholera

El objetivo del documento es contribuir a disminuir la incidencia y letalidad del cólera en Bolivia en el momento epidemiológico actual correspondiente al periodo 1995-1996.

Políticas de bioseguridad / Policies of biosafety

Esta presentación se refiere al tema de politica de bioseguridad, y abarca varios temas como: encuesta sobre inyecciones seguras, promocion de la salud, reglamento y norma boliviana de residuos sólidos generados en establecimientos de salud y manejo de farmacos