Factors associated with Chikungunya infection in a cohort of women aged 15-39 y in Fortaleza, Brazil.

BACKGROUND: Outbreaks of Chikungunya virus (CHIKV) occurred in Brazil during 2015-2017. Fortaleza was the city that reported the most cases. METHODS: The first round of a cohort study was conducted among women aged 15-39 y in Fortaleza, Brazil, in 2018 (Zika in Fortaleza). We collected sera to detect CHIKV IgG and IgM antibodies. Factors for CHIKV infection were identified using a Poisson regression model. RESULTS: We evaluated 1466 serum samples and 13.8% and 37.2% of women were found positive for CHIKV IgM and IgG antibodies, respectively. Living with more than four others in the same house and having an abandoned house nearby were associated with CHIKV infection. Being currently pregnant was associated with a decreased probability of CHIKV infection, which was also associated with pregnant women reporting using more repellent, both inside and outside the house, than non-pregnant women. CONCLUSIONS: Crowding in households and abandoned houses nearby can increase potential transmission. Policies providing better living conditions and regulation of abandoned sites and buildings are necessary to control the mosquito population. Programmes providing repellant at low or no cost to pregnant women should be implemented in the neighbourhoods where arbovirus infections are endemic.

ZIKATracker: A mobile App for reporting cases of ZIKV worldwide.

We have developed a mobile App called ZIKATracker (zikatracker.net) to voluntarily be used to report ZIKV cases on a public or private level. As the Zika virus (ZIKV) infection zones are rapidly expanding across South, Central, and North America, and reports have emerged linking ZIKV infection with developmental defects and neurological sequelae, reporting the movement and sequelae of ZIKV is essential. ZIKATracker is a multi-lingual App (English, French, Spanish, and Portuguese) freely available to anyone worldwide wishing to report a suspected or confirmed case of Zika virus and related symptoms. Knowledge gained from the use of this App will help direct the implementation of mosquito control measures in needed areas, bring aid to those affected by the Zika virus, and understand the movement and sequelae of ZIKV as it spreads through communities and across continents.

Arterial hypertension and skin allergy are risk factors for progression from dengue to dengue hemorrhagic fever: a case control study.

BACKGROUND: Currently, knowledge does not allow early prediction of which cases of dengue fever (DF) will progress to dengue hemorrhagic fever (DHF), to allow early intervention to prevent progression or to limit severity. The objective of this study is to investigate the hypothesis that some specific comorbidities increase the likelihood of a DF case progressing to DHF. METHODS: A concurrent case-control study, conducted during dengue epidemics, from 2009 to 2012. Cases were patients with dengue fever that progressed to DHF, and controls were patients of dengue fever who did not progress to DHF. Logistic regression was used to estimate the association between DHF and comorbidities. RESULTS: There were 490 cases of DHF and 1,316 controls. Among adults, progression to DHF was associated with self-reported hypertension (OR = 1.6; 95% CI 1.1-2.1) and skin allergy (OR = 1.8; 95% CI 1.1-3.2) with DHF after adjusting for ethnicity and socio-economic variables. There was no statistically significant association between any chronic disease and progression to DHF in those younger than 15 years. CONCLUSIONS: Physicians attending patients with dengue fever should keep those with hypertension or skin allergies in health units to monitor progression for early intervention. This would reduce mortality by dengue.

Reduced oviposition of Aedes aegypti gravid females in domestic containers with predatory fish.

The presence of pathogens or predators in water may alter oviposition behaviour of gravid female Aedes aegypti mosquitoes. We evaluated the oviposition behaviour of A. aegypti in recipients containing larvivorous fish (Betta splendens and Poecilia reticulata). In four breeders, fish specimens were placed in 15 l of dechlorined water. Four control breeders only contained dechlorined water. Breeders with eucatex ovitraps and approximately 100 male and female mosquitoes were placed in wire netting cages. During a period of 7 weeks, eggs on the ovitraps were counted weekly. The median number of eggs laid in recipients with B. splendens (32.5/week) was lower than in those with P. reticulata (200.5/week) and the control group (186.5/week; P < 0.0001). The oviposition activity index (OAI) for P. reticulata did not show any considerable difference between posture in deposits with and without fish (-0005). Deposits with B. splendens showed a lower position than those used as controls (-0627). We conclude that B. splendens can be used to effectively prevent gravid A. aegypti females from laying eggs in large water containers.

Avaliação do impacto na infestação por Aedes aegypti em tanques de cimento do município de Canindé, Ceará, Brasil, após a utilização do peixe Betta splendens como alternativa de controle biológico / Evaluation of the impact on Aedes aegypti infestation in cement tanks of the municipal district of Canindé, Ceará, Brazil after using the Betta splendens fish as an alternative biological control

Canindé apresenta uma população de 71.235 habitantes. Em abril de 2001 iniciou a utilização de peixes larvófagos em tanques de cimento, localizados ao nível do solo, como forma de controle biológico para larvas de Aedes aegypti. Durante a visita do agente, ao invés de se tratar os tanques com larvicida, colocou-se um espécime do peixe Betta splendens por depósito. O presente trabalho teve como objetivo avaliar os resultados desta intervenção. Com os levantamentos do número de imóveis e depósitos existentes, estimou-se este número mês a mês determinando então o número de depósitos existentes por imóvel. Com esta estimativa e o número de imóveis visitados mensalmente analisou-se a infestação deste tipo de depósito. Em janeiro de 2001, 70,4 por cento dos tanques examinados apresentavam larvas; e apenas 7,4 por cento em janeiro de 2002. Em dezembro de 2002 este índice caiu para 0,2 por cento. Demonstrou-se com clareza a capacidade do Betta splendens como agente de controle biológico, em tanques de cimento, reduzindo 320 vezes a infestação deste tipo de recipiente de grande volume.

[Evaluation of the impact on Aedes aegypti infestation in cement tanks of the municipal district of Canindé, Ceará, Brazil after using the Betta splendens fish as an alternative biological control]. / Avaliação do impacto na infestação por Aedes aegypti em tanques de cimento do município de Canindé, Ceará, Brasil, após a utilização do peixe Betta splendens como alternativa de controle biológico.

Canindé has a population of 71,235 inhabitants. In April 2001, the city started using larvivorous fish in cement water tanks, as a means of biological control of Aedes aegypti larvae. During house-to-house visits by health agents, instead of treating the water tank with larvicide, a Betta splendens fish was introduced into each tank. The number of houses and the number of tanks was estimated by monthly surveys. Then, the number of tanks per house was determined. Taking into account this estimated number and the number of houses visited, the infestation level for each kind of deposit was analyzed. In January 2001, 70.4% of the water tanks presented mosquitoes. Following the intervention, in January 2002 only 7.4% were positive and by December 2002 the rate had dropped to 0.2%. The efficacy of Betta splendens as a biological control agent in cement water tanks was clearly demonstrated, by achieving a 320 times reduction in the infestation level.