Replacing oxamniquine by praziquantel against Schistosoma mansoni infection in a rural community from the sugar-cane zone of Northeast Brazil: an epidemiological follow-up

A group of 52 villagers was followed-up for three years regarding Schistosoma mansoni infection. All villagers were periodically surveyed by the Kato-Katz method. In March 1997 and March 1998 the positives were treated with oxamniquine (15-20 mg/kg), and in March 1999, with praziquantel (60 mg/kg). All infection indices decreased substantially between March 1999 and March 2000: prevalence of infection (from 32.7% to 21.2%), prevalence of moderate/heavy infection (from 7.7% to 1.9%), intensity of infection (from 23.1 epg to 7.4 epg) and reinfection (from 35.7% to 14.3%). Negativation increased from 53.8 to 82.4. An optimistic prognostic is assumed in the short term for the introduction of praziquantel in the study area.

Epidemiological Aspects of Head Lice in Children Attending Day Care Centres, Urban and Rural Schools in Uberlândia, Central Brazil

From November 1996 to March 2000, a total of 884 children between 0 and 15 years, from 11 institutions including day care centres, public urban and public rural schools in Uberlândia, State of Minas Gerais, central Brazil, were examined for head louse infestation. Children's sex, race, age and some hairs characteristics were shown to be associated to parasite infestation. A prevalence rate of 35% was found and the highest rates were observed in black, female children, with long, dark, wavy hairs. Hairs density and thickness did not seem to influence significantly the distribution of this pediculosis in Uberlândia's schoolchildren. Differences observed between the prevalence rates of head lice in children from the urban institutions suggest there is a greater epidemiological heterogeneity in this group when compared to the rural schoolchildren.

A Rural Community in a Brazilian Western Amazonian Region: Some Demographic and Epidemiological Patterns

Some demographic and epidemiological patterns of the rural population of Monte Negro, locality situated in the State of Rondônia (Brazil), Western Amazonia, are described based on a sample of 924 randomly selected individuals, approximately 10% of the whole population. The main features of this sample are (1) the illiteracy rates in the parental generation were 23% for fathers and 20% for mothers. Among children, this figure dropped to 6%; (2) housing in Monte Negro is characterized by being constructed with wood (92%), and also a floor (75%). Nevertheless, only 32% of these houses had electric energy; (3) the mean ages for the parental generation were 41.9 for males and 36.3 for females. These values for the offspring generation were 12.2 and 10.5, respectively; (4) the sex-ratio of the offspring generation was 1.32;(5) the bioassay of kinship was estimated as .033 for this long range migrant population; (6) the prevalence of some macrophage dependent infectious disease was conspicuously high; (7) the reported number of malarial episodes among males and females was statistically different, suggesting that malaria may be, in part, a "professional" disease; (8) the prevalence of serum-positive reactions against B-hepatitis is distressing. It has a strong age dependence and reaches 74% among adult males. Conversely, signs of active infection (AgHbs) rises to 16% among children.

Field trials of an improved cost-effective device for detecting peridomestic populations of Triatoma infestans (Hemiptera: Reduviidae) in rural Argentina

An improved device for detecting peridomestic Triatoma infestans consisting of one-liter recycled Tetra Brik milk boxes with a central structure was tested using a matched-pair study design in two rural areas in Argentina. In Olta (La Rioja), the boxes were installed beneath the thatched roofs and on the vertical wooden posts of each peridomestic structure. After a 5-month exposure, at least one of the recovered boxes detected 88% of the 24 T. infestans-positive sites, and 86% of the 7 negative sites by timed manual collections at baseline. In Amamá (Santiago del Estero), the boxes were paired with the best performing prototype tested before (shelter unit). After 3 months, some evidence of infestation was detected in 89% (boxes) and 79% (shelters) of 18-19 sites positive by timed collections, whereas 19% and 16% of 32 negative sites were positive, respectively. Neither device differed significantly in the qualitative or quantitative collection of every sign of infestation. The installation site did not modify significantly the boxes' sampling efficiency in both study areas. As the total cost of each box was half as expensive as each shelter unit, the boxes are thus the most cost-effective and easy-to-use tool for detecting peridomestic T. infestans currently available.