Behavioral, climatic, and environmental risk factors for Zika and Chikungunya virus infections in Rio de Janeiro, Brazil, 2015-16.

The burden of arboviruses in the Americas is high and may result in long-term sequelae with infants disabled by Zika virus infection (ZIKV) and arthritis caused by infection with Chikungunya virus (CHIKV). We aimed to identify environmental drivers of arbovirus epidemics to predict where the next epidemics will occur and prioritize municipalities for vector control and eventual vaccination. We screened sera and urine samples (n = 10,459) from residents of 48 municipalities in the state of Rio de Janeiro for CHIKV, dengue virus (DENV), and ZIKV by molecular PCR diagnostics. Further, we assessed the spatial pattern of arbovirus incidence at the municipal and neighborhood scales and the timing of epidemics and major rainfall events. Lab-confirmed cases included 1,717 infections with ZIKV (43.8%) and 2,170 with CHIKV (55.4%) and only 29 (<1%) with DENV. ZIKV incidence was greater in neighborhoods with little access to municipal water infrastructure (r = -0.47, p = 1.2x10-8). CHIKV incidence was weakly correlated with urbanization (r = 0.2, p = 0.02). Rains began in October 2015 and were followed one month later by the largest wave of ZIKV epidemic. ZIKV cases markedly declined in February 2016, which coincided with the start of a CHIKV outbreak. Rainfall predicted ZIKV and CHIKV with a lead time of 3 weeks each time. The association between rainfall and epidemics reflects vector ecology as the larval stages of Aedes aegypti require pools of water to develop. The temporal dynamics of ZIKV and CHIKV may be explained by the shorter incubation period of the viruses in the mosquito vector; 2 days for CHIKV versus 10 days for ZIKV.

Characterization of Leishmania infantum species in dogs from the urban area of Cuiabá, State of Mato Grosso, Brazil.

INTRODUCTION: Visceral leishmaniasis presents urban behavior in some Brazilian cities, with domestic dogs as the main infection source. In Cuiabá, MT, canine visceral leishmaniasis was diagnosed and characterized as recommended by the Ministry of Health. METHODS: Biological samples from suspected canine carriers were analyzed by the isoenzyme electrophoresis technique. The 6PGDH enzyme and reference strain IOC/L0566 (MHOM/BR/1975/M2903) of Leishmania (Leishmania) infantum was used as one of the controls. RESULTS: Electrophoresis analysis revealed that the canine isolates belonged to the species L. (L.) infantum. CONCLUSIONS: The authors emphasize the importance of species characterization, particularly in areas of mixed infection like Cuiabá.

Performance of DPP™ immunochromathographic rapid test (IRT) for canine visceral leishmaniasis:comparison with other serological methods in suspected dogs from Cuiabá, Mato Grosso State, Brazil / Desempenho do teste rápido imunocromatográfico (TRI) para o diagnóstico da leishmaniose visceral canina: comparação com outros métodos sorológicos em cães suspeitos de Cuiabá, Mato Grosso, Brasil

The immunochromathographic rapid test (IRT) for canine visceral leishmaniasis (CVL) was tested in suspected dogs from the urban area of Cuiabá. The performance of IRT was compared with IFT and EIE and the direct parasitological test (DPT) as the gold standard. The sample, comprising 45 dogs, was selected by the Zoonosis Control Center. Twenty (51%) were male and thirty-four (75.5%) were both mongrel and had an estimated age of less than three years old. According to clinical data and lab tests: 10 (26.3%) dogs have been classified as exposed or infected and 18 (47.4%) as sick. IRT has achieved the best result for sensibility, 62%, high specificity, 87% and for positive and negative predictive values: 83.3% and negative 81.48%, respectively, reinforced by a k coefficient equal to 0.50, representing substantial agreement.

O teste rápido imunocromatográfico (TRI) para leishmaniose visceral canina (LVC) foi testado em cães suspeitos da área urbana de Cuiabá. O desempenho do teste foi comparado com RIFI e ELISA e, como padrão ouro, o teste parasi- tológico direto (TPD). A amostra com 45 cães foi selecionada pelo Centro de Controle de Zoonoses, sendo 23 (51,1%) machos, 34 (75,5%) sem raça definida e com idade estimada inferior a três anos. De acordo com os dados clínicos e os exames laboratoriais, 10 (26,3%) cães foram classificados como expostos, outros 10 (26,3%) como infectados e 18 (47,4%) como doentes. O TRI alcançou os melhores resultados quanto à sensibilidade, 62%, elevada especificidade, 87% e para os valores preditivos positivo e negativo: 83,30% e 81,48%, respectivamente, consolidado pelo coeficiente Kappa igual a 0,50, de concordância moderada. Os resultados confirmaram TRI como um bom preditor de doença e infecção para LVC.