[The epidemiological determinant aspects in the maintenance of visceral leishmaniasis in the state of Maranhão, Brazil]. / Aspectos epidemiológicos determinantes na manutenção da leishmaniose visceral no Estado do Maranhão--Brasil.

The authors analysed the visceral leishmaniasis (VL) aspects in the state of Maranhão, Brazil, from 1982 to 1993. The disease happens to occur predominantly in São Luís Island (MA) and during the epidemic period, town of São Luís was pointed out as the main endemic area. The greatest frequency of cases occurred in 1993, despite the use of insecticide and dogs control. There was predominance of age between 0- to 4-year-old population with 58.04% of cases. Neither the human disease nor the rainfall index had significant seasonal variation. However they were correlated moderately, with high number of cases after the period of great precipitation of rain. After this study, the data obtained will allow a better control of the disease, despite some factors such as: the urbanization, localization and dynamic of transmission in endemic areas in the Maranhão state.

Rotavirus associated diarrhoea during infancy in the city of S. Luís (MA), Brazil: a two-year longitudinal study.

A total of 479 diarrhoeic children and 337 children without diarrhoea (controls) less than 5 years old were investigated in a two-year study in the city of S. Luís (MA), with the purpose to determine the incidence, the age distribution and the seasonality of rotaviruses, as well as to establish the severity of the disease in this region between the North and the Northeast of Brazil. rotavirus incidence was highest in children of the 1st. year of life, showing an average of 25% per year among the diarrhoeic patients attending the two main hospitals and three health units at the periphery of the city. It was shown that rotaviruses are significant enteropathogens in children less than 18 months old. Frequency of rotaviruses dropped in diarrhoeic patients 18 to 23 months old to only 4%, the same percentage observed in children of the control group. A typical seasonal distribution of rotaviruses was not seen during the two years of study. There was a peak in the incidence of rotaviruses in 1986, during the rainy season, and two peaks in 1987, one in the rainy season and one in the dry season. It was also shown that severity of diarrhoea in rotavirus positive cases was higher than in the negative cases. Rotavirus diarrhoeic patients had more loose stools per day, and higher frequencies of vomiting and fever, resulting more often (> 2 times) in moderate or severe dehydration. Finally, it is concluded that the introduction of immunoprophylaxis may reduce significantly the high mortality rates in early childhood observed in S. Luís.