Variação dia a dia da prevalência e da intensidade de Schistosoma haematobium e ecologia do vector na Ilha de Inhaca

Abstract

The present work was carried out on Inhaca Island between February and May 1995. The day-to-day variation in the prevalence and intensity of S, haematobium was determined from urine analysis on six consecutive days by the filtration method. In this study, only students aged 6 to 18 years old who completed the 6 days of consecutive analyzes were considered (110 out of 160 students investigated). The total daily prevalence varies between 30.0% and 40.0%. The difference between the total daily prevalences and the total cumulative prevalence of 6 days of consecutive analyzes (50.9%) is significant (x2=28.79; G.L.= 5; p<<0.001). Four days of consecutive analyzes are sufficient to obtain the maximum cumulative prevalence. The intensity of infection in one-day positive students ranges from 0 to 2050-3250 eggs/10 ml of urine. Infections with 1-49 eggs/10 ml of urine (sub-acute) are the main cause of variation in the prevalence of S. haematobium. In sub-acute infections, on average, one-day positives are negative in 61.2 % on any of the other 5 exams. There is a significant difference (x2= 34.67; G.L. = 10; p<< 0.001) between the number of positive days for sub-acute infections and the number of positive days for acute infections (≥50 eggs/10 ml of urine). In daily prevalence, acute infections predominate. In the total cumulative prevalence, sub-acute infections predominate. There is no significant difference (x2=3.143; G.L.= 5; p<0.25) between the geometric mean of eggs counted (GMEC) in one day and the GMEC in 6 days of consecutive analyses. The capture of vector snails of Schistosoma haematobium was carried out in fifteen (13 wells and 2 ditches) sites most visited by the students, and temperature, O2, pH and salinity were measured. Fresh water, in addition to wells, was only found in the swampy area of ​​Langua Funguene. 216 snails were captured of which 49.5% are vectors of S. haematobium. Temperature varies between 21.0 and 25.0 °C; O2 varies between 1.0 and 7.0 mg/L. The pH varies between 3.6 and 6.6. Salinity varies between 0.0 and 7.0 mg/L. The pH and salinity influence the distribution of snails in Inhaca. Mais sobre o texto original É necessário fornecer o texto original para ver mais informações sobre a tradução (TRADUÇÃO NOSSA)