"Where we put little fish in the water there are no mosquitoes:" a cross-sectional study on biological control of the Aedes aegypti vector in 90 coastal-region communities of Guerrero, Mexico.

BACKGROUND: In the Mexican state of Guerrero, some households place fish in water storage containers to prevent the development of mosquito larvae. Studies have shown that larvivorous fish reduce larva count in household water containers, but there is a lack of evidence about whether the use of fish is associated with a reduction in dengue virus infection. We used data from the follow up survey of the Camino Verde cluster randomised controlled trial of community mobilisation to reduce dengue risk to study this association. METHODS: The survey in 2012, among 90 clusters in the three coastal regions of Guerrero State, included a questionnaire to 10,864 households about socio-demographic factors and self-reported cases of dengue illness in the previous year. Paired saliva samples provided serological evidence of recent dengue infection among 4856 children aged 3-9 years. An entomological survey in the same households looked for larvae and pupae of Aedes aegypti and recorded presence of fish and temephos in water containers. We examined associations with the two outcomes of recent dengue infection and reported dengue illness in bivariate analysis and then multivariate analysis using generalized linear mixed modelling. RESULTS: Some 17% (1730/10,111) of households had fish in their water containers. The presence of fish was associated with lower levels of recent dengue virus infection in children aged 3-9 years (OR 0.64; 95% CI 0.45-0.91), as was living in a rural area (OR 0.57; 95% CI 0.45-0.71), and being aged 3-5 years (OR 0.65; 95% CI 0.51-0.83). Factors associated with lower likelihood of self-reported dengue illness were: the presence of fish (OR 0.79; 95% CI 0.64-0.97), and living in a rural area (OR 0.74; 95% CI 0.65-0.84). Factors associated with higher likelihood of self-reported dengue illness were: higher education level of the household head (OR 1.28; 95% CI 1.07-1.52), living in a household with five people or less (OR 1.33; 95% CI 1.16-1.52) and household use of insecticide anti-mosquito products (OR 1.68; 95% CI 1.47-1.92). CONCLUSIONS: Our study suggests that fish in water containers may reduce the risk of dengue virus infection and dengue illness. This could be a useful part of interventions to control the Aedes aegypti vector.

Aedes aegypti breeding ecology in Guerrero: cross-sectional study of mosquito breeding sites from the baseline for the Camino Verde trial in Mexico.

BACKGROUND: Understanding the breeding patterns of Aedes aegypti in households and the factors associated with infestation are important for implementing vector control. The baseline survey of a cluster randomised controlled trial of community mobilisation for dengue prevention in Mexico and Nicaragua collected information about the containers that are the main breeding sites, identified possible actions to reduce breeding, and examined factors associated with household infestation. This paper describes findings from the Mexican arm of the baseline survey. METHODS: In 2010 field teams conducted household surveys and entomological inspections in 11,995 households from 90 representative communities in the three coastal regions of Guerrero State, Mexico. We characterized Ae. aegypti breeding sites and examined the effect of two preventive measures: temephos application in water containers, and keeping the containers covered. We examined associations with household infestation, using bivariate and multivariate analysis adjusted for clustering effects. RESULTS: We conducted entomological inspections in 11,995 households. Among 45,353 water containers examined, 6.5% (2958/45,353) were positive for larvae and/or pupae. Concrete tanks (pilas) and barrels (tambos) together accounted for 74% of pupal productivity. Both covering water containers and inserting temephos were independently associated with a lower risk of presence of larvae or pupae, with the effect of covering (OR 0.22; 95% CIca 0.15-0.27) stronger than that of temephos (OR 0.66; 95% CIca 0.53-0.84). Having more than four water containers was associated with household infestation in both rural areas (OR 1.42; 95% CIca 1.17-1.72) and urban areas (1.81; 1.47-2.25), as was low education of the household head (rural: 1.27; 1.11-1.46, and urban: 1.39; 1.17-1.66). Additional factors in rural areas were: household head without paid work (1.31; 1.08-1.59); being in the Acapulco region (1.91; 1.06-3.44); and using anti-mosquito products (1.27; 1.09-1.47). In urban areas only, presence of temephos was associated with a lower risk of household infestation (0.44; 0.32-0.60). CONCLUSION: Concrete tanks and barrels accounted for the majority of pupal productivity. Covering water containers could be an effective means of Ae. aegypti vector control, with a bigger effect than using temephos. These findings were useful in planning and implementing the Camino Verde trial intervention in Mexico.

Which green way: description of the intervention for mobilising against Aedes aegypti under difficult security conditions in southern Mexico.

BACKGROUND: Community mobilisation for prevention requires engagement with and buy in from those communities. In the Mexico state of Guerrero, unprecedented social violence related to the narcotics trade has eroded most community structures. A recent randomised controlled trial in 90 coastal communities achieved sufficient mobilisation to reduce conventional vector density indicators, self-reported dengue illness and serologically proved dengue virus infection. METHODS: The Camino Verde intervention was a participatory research protocol promoting local discussion of baseline evidence and co-design of vector control solutions. Training of facilitators emphasised community authorship rather than trying to convince communities to do specific activities. Several discussion groups in each intervention community generated a loose and evolving prevention plan. Facilitators trained brigadistas, the first wave of whom received a small monthly stipend. Increasing numbers of volunteers joined the effort without pay. All communities opted to work with schoolchildren and for house-to-house visits by brigadístas. Children joined the neighbourhood vector control movements where security conditions permitted. After 6 months, a peer evaluation involved brigadista visits between intervention communities to review and to share progress. DISCUSSION: Although most communities had no active social institutions at the outset, local action planning using survey data provided a starting point for community authorship. Well-known in their own communities, brigadistas faced little security risk compared with the facilitators who visited the communities, or with governmental programmes. We believe the training focus on evidence-based dialogue and a plural community ownership through multiple design groups were key to success under challenging security conditions. TRIAL REGISTRATION: ISRCTN27581154 .

Dengue occurrence relations and serology: cross-sectional analysis of results from the Guerrero State, Mexico, baseline for a cluster-randomised controlled trial of community mobilisation for dengue prevention.

BACKGROUND: The Mexican arm of the Camino Verde trial of community mobilisation for dengue prevention covered three coastal regions of Guerrero state: Acapulco, Costa Grande and Costa Chica. A baseline cross-sectional survey provided data for community mobilisation and for adapting the intervention design to concrete conditions in the intervention areas. METHODS: Trained field teams constructed community profiles in randomly selected clusters, based on observation and key informant interviews. In each household they carried out an entomological inspection of water containers, collected information on socio-demographic variables and cases of dengue illness among household members in the last year, and gathered paired saliva samples from children aged 3-9 years, which were subjected to ELISA testing to detect recent dengue infection. We examined associations with dengue illness and recent dengue infection in bivariate and then multivariate analysis. RESULTS: In 70/90 clusters, key informants were unable to identify any organized community groups. Some 1.9% (1029/55,723) of the household population reported dengue illness in the past year, with a higher rate in Acapulco region. Among children 3-9 years old, 6.1% (392/6382) had serological evidence of recent dengue infection. In all three regions, household use of anti-mosquito products, household heads working, and households having less than 5 members were associated with self-reported dengue illness. In Acapulco region, people aged less than 25 years, those with a more educated household head and those from urban sites were also more likely to report dengue illness, while in Costa Chica and Costa Grande, females were more likely to report dengue illness. Among children aged 3-9 years, those aged 3-4 years and those living in Acapulco were more likely to have evidence of recent dengue infection. CONCLUSIONS: The evidence from the baseline survey provided important support for the design and implementation of the trial intervention. The weakness of community leadership and the relatively low rates of self-reported dengue illness were challenges that the Mexican intervention team had to overcome. The higher dengue illness occurrence among women in Costa Grande and Costa Chica may help explain why women participated more than men in activities during the Camino Verde trial.

[Hepatitis B vaccination coverage and associated factor for vaccine acceptance: a cross-sectional study in health workers of the Acapulco General Hospital, Mexico]. / Cobertura de vacunación contra el virus de la hepatitis B (VHB) y factores asociados: un estudio transversal en trabajadores del Hospital General de Acapulco, México.

BACKGROUND: Vaccination is a key current prophylactic measure for occupational risk of hepatitis B virus (HBV) infection. This study measures HBV vaccination coverage among health personnel in a Mexican hospital, and identifies factors associated with completion of the vaccination schedule. METHODS: A cross-sectional study in workers of the Acapulco General Hospital, Mexico. Interviews documented vaccination history against HBV, number of doses received, and date of vaccination. Health workers with complete vaccination were considered those with at least three doses of vaccine received at intervals of two months between first and second doses, and six months to a year in the third dose. RESULTS: Some 52% of workers (436/834) reported at least one vaccination during their professional life and only 5.5% (46/834) completed the HBV vaccination schedule. Factors associated with completion were academic degree, perception of infection risk at work, and knowledge of vaccine efficacy and the need for a complete schedule. CONCLUSIONS: In line with hospitals in other studies, few hospital workers were fully vaccinated. Evidence from this study can inform efforts to increase HBV vaccination coverage.

Factors Associated with Chikungunya Relapse in Acapulco, Mexico: A Cross-Sectional Study.

Objective: To estimate the occurrence of self-reported chikungunya relapse and identify associated factors. Materials and Methods: A cross-sectional study in December 2015 included 1305 homes in eight urban clusters considered representative of Acapulco in southern Mexico. Administered questionnaires collated information on 5870 individuals, including sociodemographic variables, a history of chronic conditions, and the self-reporting of chikungunya. Bivariate and multivariate analyses relied on a cluster-adjusted Mantel-Haenszel procedure to identify the factors associated with chikungunya and its relapse. Results: Some 66% (3531/5870) of the population reported suffering chikungunya and 31.1% (1098/3531) reported a relapse. Factors associated with relapse included the severity of the chikungunya case (odds ratio [OR]: 3.35; clusters adjusted 95% confidence interval [95% CIca]: 3.16-3.55); history of arthralgia (OR: 2.96; 95% CIca: 2.27-3.86); age 30 years or older (OR: 1.85; 95% CIca: 1.72-1.98); female (OR: 1.64; 95% CIca: 1.42-1.90); and higher education households (OR: 1.18; 95% CIca: 1.11-1.27). Conclusions: The high occurrence of chikungunya and its relapse are a public health problem. The factors associated with relapse do not immediately suggest specific prevention strategies but emphasize the dire need for effective approaches to vector control.

El sobrepeso y obesidad en estudiantes de primaria de dos municipios de la Costa Chica de Guerrero, México / Overweight and obesity in elementary students from two municipalities of the Costa Chica de Guerrero, Mexico / Sobrepeso e obesidade em estudantes do ensino fundamental de dois municípios da Costa Chica de Guerrero, México

Resumen El objetivo de esta investigación fue estudiar la prevalencia de sobrepeso, obesidad y factores asociados en estudiantes de 5° y 6° grado de primaria en dos municipios de la Costa Chica de Guerrero. Se llevó a cabo un estudio descriptivo transversal. Para la recopilación de información se utilizó una báscula digital para registrar las medidas antropométricas y, se aplicó un cuestionario, que incluyó variables relacionadas con hábitos alimenticios, actividad física, tiempo dedicado a ver televisión (TV) y tiempo dedicado a dormir. Se encontró que el 16% de los estudiantes tuvo sobrepeso y 15% obesidad. Hubo mayor riesgo de padecer la enfermedad metabólica en los participantes que ven TV más de 5 h/día (ORns Cl adj = 1.72.IC 95% 1.27-2.34), mientras que comer cuatro o más veces al día tuvo un efecto protector (ORns Cl adj = 0.47, IC 95% 0.31-0.72). En los municipios de Cruz Grande y San Marcos los estudiantes de 5° y 6° de primaria tienen un grado medio de sobrepeso y obesidad; ya que el sedentarismo no es tan marcado y existe la tendencia a practicar el deporte. Se concluye que disminuir el número de horas frente al televisor y la correcta alimentación son acciones que pueden contribuir a la prevención y disminución del sobrepeso y la obesidad en estudiantes de primaria.

Abstract The objective of this research was to study the prevalence of overweight, obesity and associated factors in students of 5th and 6th grade of primary school in two municipalities of the Costa Chica, Guerrero. A crosssectional descriptive study was carried out. For the collection of information, a digital scale was used to record the anthropometric measurements and, a questionnaire was applied, which included variables related to eating habits, physical activity, time spent watching television (TV) and time spent sleeping. It was found that 16% of the students were overweight and 15% obese. There was an increased risk of metabolic disease in participants who watched TV more than 5 h / day (ORns Cl adj = 1.72.IC 95% 1.27-2.34), while eating four or more times a day had a protective effect (ORns Cl adj = 0.47, 95% CI 0.31-0.72). In the municipalities of Cruz Grande and San Marcos, students in grades 5 and 6 have a medium degree of overweight and obesity; since sedentary lifestyle is not as marked and there is a tendency to practice sports. It is concluded that reducing the number of hours in front of the television and the correct feeding are actions that can contribute to the prevention and reduction of overweight and obesity in elementary students.

Resumo O objetivo desta pesquisa foi estudar a prevalência de sobrepeso, obesidade e fatores associados em estudantes da 5ª e 6ª séries do ensino fundamental de dois municípios da Costa Chica de Guerrero. Foi realizado um estudo descritivo transversal. Para a coleta de informações, utilizou-se uma escala digital para registro das medidas antropométricas e aplicou-se um questionário, que incluiu variáveis relacionadas aos hábitos alimentares, atividade física, tempo gasto assistindo televisão (TV) e tempo gasto dormindo. Verificou-se que 16% dos estudantes estavam com sobrepeso e 15% com obesidade. Houve um risco aumentado de doença metabólica nos participantes que assistiram TV mais de 5 h / dia (ORns Cl adj = 1,72.IC 95% 1,27-2,34), enquanto comer quatro ou mais vezes por dia teve um efeito protetor (ORns Cl adj = 0,47, IC 95% 0,31-0,72). Nos municípios de Cruz Grande e San Marcos, os alunos das séries 5 e 6 apresentam sobrepeso e obesidade médios; uma vez que o estilo de vida sedentário não é tão acentuado e existe uma tendência a praticar esportes. Conclui-se que reduzir o número de horas em frente à televisão e a alimentação correta são ações que podem contribuir para a prevenção e redução do sobrepeso e obesidade em alunos do ensino fundamental.