Effectiveness of oral cholera vaccine in preventing cholera among fishermen in Lake Chilwa, Malawi: A case-control study.

BACKGROUND: In response to a cholera outbreak among mobile, difficult-to-reach fishermen on Lake Chilwa, Malawi in 2016, a novel vaccine distribution strategy exploited the proven vaccine thermostability. Fishermen, while taking the first vaccine dose under supervision, received the second dose in a sealed bag, and were told to drink it two weeks later. This study assessed short-term vaccine protection of this strategy. METHODS: Patients with diarrhoea admitted to health facilities around lake were interviewed and a stool sample collected for PCR testing. Vaccine effectiveness was assessed in a case-control test-negative design by comparing cases (PCR-positive for V. cholerae O1) and controls (patients with diarrhoea but PCR-negative) and with the screening method that compared the proportions of vaccinated among cholera cases versus the general fishermen population. RESULTS: Of 145 study participants, 120 were fishermen living on the lake. Vaccine effectiveness at three-months was 90.0% [95%CI:38.8;98.4] among fishermen and 83.3% [95%CI: 20.8; 96.5] among all participants in the case-control test-negative design, and 97.5% [95%CI: 90.9;99.3] with the screening method. CONCLUSION: This strategy was effective in providing short-term protection in fishermen against cholera. Further research is needed to determine the adding value of the second dose and to identify the optimal vaccination strategies for different contexts.

Oral cholera vaccination in hard-to-reach communities, Lake Chilwa, Malawi.

OBJECTIVE: To evaluate vaccination coverage, identify reasons for non-vaccination and assess satisfaction with two innovative strategies for distributing second doses in an oral cholera vaccine campaign in 2016 in Lake Chilwa, Malawi, in response to a cholera outbreak. METHODS: We performed a two-stage cluster survey. The population interviewed was divided in three strata according to the second-dose vaccine distribution strategy: (i) a standard strategy in 1477 individuals (68 clusters of 5 households) on the lake shores; (ii) a simplified cold-chain strategy in 1153 individuals (59 clusters of 5 households) on islands in the lake; and (iii) an out-of-cold-chain strategy in 295 fishermen (46 clusters of 5 to 15 fishermen) in floating homes, called zimboweras. FINDING: Vaccination coverage with at least one dose was 79.5% (1153/1451) on the lake shores, 99.3% (1098/1106) on the islands and 84.7% (200/236) on zimboweras. Coverage with two doses was 53.0% (769/1451), 91.1% (1010/1106) and 78.8% (186/236), in the three strata, respectively. The most common reason for non-vaccination was absence from home during the campaign. Most interviewees liked the novel distribution strategies. CONCLUSION: Vaccination coverage on the shores of Lake Chilwa was moderately high and the innovative distribution strategies tailored to people living on the lake provided adequate coverage, even among hard-to-reach communities. Community engagement and simplified delivery procedures were critical for success. Off-label, out-of-cold-chain administration of oral cholera vaccine should be considered as an effective strategy for achieving high coverage in hard-to-reach communities. Nevertheless, coverage and effectiveness must be monitored over the short and long term.

Oral cholera vaccination in hard-to-reach communities, Lake Chilwa, Malawi

Objective To evaluate vaccination coverage, identify reasons for non-vaccination and assess satisfaction with two innovative strategies for distributing second doses in an oral cholera vaccine campaign in 2016 in Lake Chilwa, Malawi, in response to a cholera outbreak. Methods We performed a two-stage cluster survey. The population interviewed was divided in three strata according to the second-dose vaccine distribution strategy: (i) a standard strategy in 1477 individuals (68 clusters of 5 households) on the lake shores; (ii) a simplifiedcold-chain strategy in 1153 individuals (59 clusters of 5 households) on islands in the lake; and (iii) an out-of-cold-chain strategy in 295 fishermen (46 clusters of 5 to 15 fishermen) in floating homes, called zimboweras. Finding Vaccination coverage with at least one dose was 79.5% (1153/1451) on the lake shores, 99.3% (1098/1106) on the islands and 84.7% (200/236) on zimboweras. Coverage with two doses was 53.0% (769/1451), 91.1% (1010/1106) and 78.8% (186/236), in the three strata, respectively. The most common reason for non-vaccination was absence from home during the campaign. Most interviewees liked the novel distribution strategies. Conclusion Vaccination coverage on the shores of Lake Chilwa was moderately high and the innovative distribution strategies tailored to people living on the lake provided adequate coverage, even among hard-to-reach communities. Community engagement and simplified delivery procedures were critical for success. Off-label, out-of-cold-chain administration of oral cholera vaccine should be considered as an effective strategy for achieving high coverage in hard-to-reach communities. Nevertheless, coverage and effectiveness must be monitored over the short and long term

Socio-economic modelling of rotavirus vaccination in Castilla y Leon, Spain.

Rotavirus is one of the main causes of acute gastroenteritis in infants and young children. Furthermore, rotavirus is the leading cause of hospitalization and death from acute gastroenteritis among infants and young children worldwide. Although death due to rotavirus is rare in industrialized regions such as Spain, the rotavirus disease burden and its economic impact is severe. This study aims to assess systematic vaccination against rotavirus economically and socially in a Spanish region. Economic cost-effectiveness and cost-benefit assessment through a choice tree was designed. We estimated health provider costs, economic costs and quality-adjusted life years (QALYs) lost due to rotavirus infections. The study includes a fictitious cohort of 100,000 children from Castilla y Leon who were also administered the rotavirus vaccine together with diphtheria and tetanus toxoids and pertussis (DTP) . The study adopted a society and health care system perspective. A sensitivity analysis was developed to assess the uncertainty of some variables. According to the estimated incidence rate for children in Castilla y Leon, rotavirus immunization is projected to prevent 45% of cases with RotaTeq and 57% with Rotarix. The respective cost per QALY is about Euro 75,000 and 50,000 from the perspective of the health care system. Routine infant vaccination in Castilla y Leon using either rotavirus vaccine is not profitable from the payer's perspective and is not cost-effective under basic case assumptions unless the vaccine is available at a lower cost.

[Profile of paediatric admissions and emergencies during an epidemic period of rotavirus in Valladolid [Spain]. Utility of a predictive model]. / Perfil de ingresos y urgencias pediátricas en período epidémico de rotavirus en Valladolid. Utilidad de un modelo predictivo.

INTRODUCTION: The aim of this study was to determine the weeks of high rotavirus circulation in Valladolid (Spain) and to compare the characteristics of hospitalizations and emergencies in epidemic and nonepidemic periods. METHODS: The information sources consisted of the weekly notifications to the Microbiological Information System, the Minimum Data Set, and the Emergency Registry. Expected cases for 2006 were calculated using a previously developed model. Weeks with observed cases over the upper limit of the 95% confidence interval for expected cases were considered epidemic periods. Hospitalization and emergencies in epidemic and nonepidemic periods were compared. RESULTS: The number of cases in 2006 was 42% less than the expected number. The mean number of daily admissions was higher in epidemic periods (d=1.49; p=0.01) and the length of admissions was longer. CONCLUSION: The activity of the paediatric service increased during the epidemic period. Consequently, implementation of surveillance activities and prevention and control programs for rotavirus in hospitals would seem advisable.

Perfil de ingresos y urgencias pediátricas en período epidémico de rotavirus en Valladolid. Utilidad de un modelo predictivo / Profile of paediatric admissions and emergencies during an epidemic period of rotavirus in Valladolid [Spain]. Utility of a predictive model

Introducción: Este estudio pretende determinar las semanas de alta circulación de rotavirus en valladolid, y comparar las características de los ingresos y urgencias en período epidémico con respecto al período no epidémico.Métodos: Se utilizaron las declaraciones al sistema de información microbiológica, el conjunto mínimo básico de datos y el registro de urgencias. Se calcularon los casos esperados para 2006 a partir de un modelo elaborado previamente. Si los casos observados superaban el umbral superior del 95% de los esperados, la semana se consideró epidémica. Se compararon las características de los ingresos y urgencias en ambos períodos.Resultados: En 2006 se diagnosticaron un 42% menos de los casos esperados. La media de ingresos diarios fue superior en período epidémico (diferencia=1,49; p=0,01), y también fue mayor la duración media del ingreso.Conclusión: La actividad del servicio de pediatría se incrementó en período epidémico, por lo que es oportuna la implantación de actividades de vigilancia, programas de prevención y control frente a rotavirus en el ámbito hospitalario(AU)

Introduction: The aim of this study was to determine the weeks of high rotavirus circulation in Valladolid (Spain) and to compare the characteristics of hospitalizations and emergencies in epidemic and nonepidemic periods.Methods: The information sources consisted of the weekly notifications to the Microbiological Information System, the Minimum Data Set, and the Emergency Registry. Expected cases for 2006 were calculated using a previously developed model. Weeks with observed cases over the upper limit of the 95% confidence interval for expected cases were considered epidemic periods. Hospitalization and emergencies in epidemic and nonepidemic periods were compared.Results: The number of cases in 2006 was 42% less than the expected number. The mean number of daily admissions was higher in epidemic periods (d=1.49; p=0.01) and the length of admissions was longer.Conclusion: The activity of the paediatric service increased during the epidemic period. Consequently, implementation of surveillance activities and prevention and control programs for rotavirus in hospitals would seem advisable(AU)