Examining the determinants of mosquito-avoidance practices in two Kenyan cities

BACKGROUND: This study assesses the behavioural and socio-economic factors associated with avoiding mosquitoes and preventing malaria in urban environments in Kenya. METHODS: Data from two cities in Kenya were gathered using a household survey and a two-stage cluster sample design. The cities were stratified based on planning and drainage observed across the urban areas. This helped control for the strong environmental and topographical variation that we assumed influences mosquito ecology. Individual interviews given to each household included questions on socio-economic status, education, housing type, water source, rubbish disposal, mosquito-prevention practices and knowledge of mosquitoes. In multivariate regression, factors measuring wealth, education level, and the communities' level of planning and drainage were used to estimate the probability that a household engages in multiple mosquito-avoidance activities, or has all members sleeping under a bed net. RESULTS: Our analysis shows that people from wealthier, more educated households were more likely to sleep under a net, in Kisumu (OR = 6.88; 95% CI = 2.56,18.49) and Malindi (OR = 3.80; 95% CI = 1.91,7.55). Similarly, the probability that households use several mosquito-prevention activities was highest among the wealthiest, best-educated households in Kisumu (OR = 5.15; 95% CI = 2.04,12.98), while in Malindi household wealth alone is the major determinant. CONCLUSION: We demonstrate the importance of examining human-mosquito interaction in terms of how access to resources may enhance human activities. The findings illustrate that the poorest segments of society are already doing many things to protect themselves from being bitten, but they are doing less than their richer neighbours

A long-lasting measles epidemic in Maroua, Cameroon 2008-2009: mass vaccination as response to the epidemic.

A measles outbreak occurred in Maroua, Cameroon, from January 2008 to April 2009. In accordance with recent World Health Organization guidelines, an outbreak-response immunization (ORI) was conducted in January 2009. The aim of this study was to investigate the causes of the epidemic in order to guide vaccination strategies

Case based measles surveillance in Pune: Evidence to guide current and future measles control and elimination efforts in India

Background: According to WHO estimates, 35% of global measles deaths in 2011 occurred in India. In 2013, India committed to a goal of measles elimination by 2020. Laboratory supported case based measles surveillance is an essential component of measles elimination strategies. Results from a case-based measles surveillance system in Pune district (November 2009 through December 2011) are reported here with wider implications for measles elimination efforts in India.Methods: Standard protocols were followed for case identification, investigation and classification. Suspected measles cases were confirmed through serology (IgM) or epidemiological linkage or clinical presentation. Data regarding age, sex, vaccination status were collected and annualized incidence rates for measles and rubella cases calculated.Results: Of the 1011 suspected measles cases reported to the surveillance system, 76% were confirmed measles, 6% were confirmed rubella, and 17% were non-measles, non-rubella cases. Of the confirmed measles cases, 95% were less than 15 years of age. Annual measles incidence rate was more than 250 per million persons and nearly half were associated with outbreaks. Thirty-nine per cent of the confirmed measles cases were vaccinated with one dose of measles vaccine (MCV1).Conclusion: Surveillance demonstrated high measles incidence and frequent outbreaks in Pune where MCV1 coverage in infants was above 90%. Results indicate that even high coverage with a single dose of measles vaccine was insufficient to provide population protection and prevent measles outbreaks. An effective measles and rubella surveillance system provides essential information to plan, implement and evaluate measles immunization strategies and monitor progress towards measles elimination

An assessment of hepatitis B vaccine introduction in India: Lessons for roll out and scale up of new vaccines in immunization programs

Background: Hepatitis B vaccine was introduced in the Universal Immunization Program (UIP) of 10 states of India in the year 2007-08. This assessment was planned and conducted to ascertain the reasons for low reported coverage of Hepatitis B (Hep B) vaccine in comparison of similarly timed diphtheria, pertussis, and tetanus (DPT) vaccine; to identify operational and programmatic challenges in new vaccine introductions, and to derive lessons for further scale up of Hep B vaccination (or for introduction of any new vaccine) in UIP of India. Materials and Methods: Purposive sampling with both quantitative and qualitative data collection. Two districts each were purposively selected from 5 of the 10 states, which introduced Hep B vaccine, in the year 2007-08. A protocol was devised and data was collected through desk review, in-depth interviews and on-site observation at state, districts and facility levels. The assessment was completed in December 2009. Results: Coverage with three doses of Hep B vaccine was lower than similarly timed three doses of DPT vaccine. Poor stock management ("stock outs or nil stocks" at various levels), incomplete recording and reporting, perceived high cost & related fear of wastage of vaccine in 10 dose vial, and incomplete knowledge amongst health functionaries about vaccination schedule were the main reasons cited for reported lower coverage. Hep B vaccine birth dose was introduced in only 3 of 5 states evaluated. The additional reasons for low Hep B birth dose coverage were lack of knowledge amongst Health Workers about birth dose administration, no mechanism for recording birth dose, and insufficient trainings, official communications, and coordination at various levels. Conclusions: This assessment documents challenges faced in the introduction of hepatitis B vaccine in UIP in India and summarizes the lessons learnt. It is concluded that for successful introduction and scale up of any new vaccine in national or state immunization program; clear and timely central level instructions and oversight and improved stock management is required. At state and district levels; quality trainings, effective supervision and monitoring, improving data recording and reporting are key factor for success. The additional focus on Hep B birth dose administration may help in improving coverage. The lessons from this assessment can possibly be utilized for future introduction and scale up of any new vaccine (or other similar interventions) in India or in any other developing country setting

Seroprevalence of measles and natural rubella antibodies among children in Bangui, Central African Republic

Abstract Background Passively acquired maternal antibodies are necessary to protect infants against circulating measles virus until they reach the eligible age of vaccination. Likewise, high levels of population immunity must be achieved and maintained to reduce measles virus transmission. This study was undertaken to (1) assess the presence of maternally acquired measles-specific IgG antibodies among infants less than 9 months of age in Bangui, Central African Republic and (2) determine the immune status of vaccination-age children and the concordance with reported vaccination status. A secondary objective was to describe the presence of rubella-specific IgG antibody in the study population. Methods Vaccination history and blood samples were collected from 395 children using blotting paper. Samples were analyzed for the presence of measles-specific IgG antibodies using commercial ELISA kits. Results Measles-specific IgG antibodies were detected in 51.3% of vaccinated children and 27.6% of non-vaccinated children. Maternally derived measles IgG antibodies were present in only 14.8% of infants aged 0-3 months and were absent in all infants aged 4-8 months. The presence of IgG-specific measles antibodies varied among children of vaccination age, from 57.3% for children aged 9 months to 5 years, to 50.6% for children aged 6-9 years and 45.6% for chidren aged 10 years and above. The overall prevalence of rubella-specific IgG was 55.4%, with a high prevalence (87.4%) among children over 10 years of age. Conclusion The findings suggest that despite efforts to accelerate measles control by giving a second dose of measles vaccine, a large number of children remain susceptible to measles virus. Further research is required to determine the geographic extent of immunity gaps and the factors that influence immunity to measles virus in the Central African Republic.</p

Cluster survey evaluation of a measles vaccination campaign in Jharkhand, India, 2012.

India was the last country in the world to implement a two-dose strategy for measles-containing vaccine (MCV) in 2010. As part of measles second-dose introduction, phased measles vaccination campaigns were conducted during 2010-2013, targeting 131 million children 9 months to <10 years of age. We performed a post-campaign coverage survey to estimate measles vaccination coverage in Jharkhand state.A multi-stage cluster survey was conducted 2 months after the phase 2 measles campaign occurred in 19 of 24 districts of Jharkhand during November 2011-March 2012. Vaccination status of children 9 months to <10 years of age was documented based on vaccination card or mother's recall. Coverage estimates and 95% confidence intervals (95% CI) for 1,018 children were calculated using survey methods.In the Jharkhand phase 2 campaign, MCV coverage among children aged 9 months to <10 years was 61.0% (95% CI: 54.4-67.7%). Significant differences in coverage were observed between rural (65.0%; 95% CI: 56.8-73.2%) and urban areas (45.6%; 95% CI: 37.3-53.9%). Campaign awareness among mothers was low (51.5%), and the most commonly reported reason for non-vaccination was being unaware of the campaign (69.4%). At the end of the campaign, 53.7% (95% CI: 46.5-60.9%) of children 12 months to <10 years of age received ≥ 2 MCV doses, while a large proportion of children remained under-vaccinated (34.0%, 95% CI: 28.0-40.0%) or unvaccinated (12.3%, 95% CI: 9.3-16.2%).Implementation of the national measles campaign was a significant achievement towards measles elimination in India. In Jharkhand, campaign performance was below the target coverage of ≥ 90% set by the Government of India, and challenges in disseminating campaign messages were identified. Efforts towards increasing two-dose MCV coverage are needed to achieve the recently adopted measles elimination goal in India and the South-East Asia region

Cluster-level measles campaign vaccination coverage in the urban and rural surveys, Jharkhand, 2012.

<p>Organ-pipe plots of unweighted coverage by cluster were constructed for urban and rural surveys (Dale Rhoda, personal communication). Design effect (DE) and intraclass correlation coefficients (ICCs) were calculated for the respective surveys.</p

Phase 2 measles vaccination campaign coverage estimates by socio-demographic characteristic for urban and rural areas, Jharkhand, 2012.

<p>Abbreviations: LCL = lower confidence limit, UCL = upper confidence limit, y = years, m = months</p><p>^a Variations in denominator due to missing data</p><p>^b Rao-Scott chi-square test; p-values denoted with * are statistically significant</p><p>^c P-value is for comparison between urban and rural surveys</p><p>Phase 2 measles vaccination campaign coverage estimates by socio-demographic characteristic for urban and rural areas, Jharkhand, 2012.</p

Socio-demographic characteristics of children in the urban and rural surveys, Jharkhand, 2012.

<p>Abbreviations: y = years, m = months</p><p>Socio-demographic characteristics of children in the urban and rural surveys, Jharkhand, 2012.</p