Schistosoma mansoni infection and related knowledge among schoolchildren in an endemic area of Minas Gerais, Brazil, prior to educational actions.

As a signatory to World Health Assembly Resolution WHA65.21 on eliminating schistosomiasis, the Brazilian Ministry of Health (MoH) recommends early identification and timely treatment of the infection carriers for morbidity control, plus complementary preventive measures, such as health education, for transmission control. This study reports infection and awareness of schistosomiasis among schoolchildren before the implementation of school-based educational actions in an endemic municipality with persisting moderate prevalence levels despite successive control campaigns since the late 1990s. A questionnaire was applied in April 2013 to schoolchildren in the middle years of schooling (6th to 8th year) of Malacacheta municipality to assess baseline knowledge and risk behaviour related to schistosomiasis. A stool survey was conducted in May/June 2013 in 2519 schoolchildren from all years of fundamental education (first to 9th year) to identify the infection carriers, as well as to assess baseline prevalence and intensity of infection using the Kato-Katz method (one sample, two slides). The infected schoolchildren were treated promptly with single-dose praziquantel 60mg/kg and followed up after 45days for treatment efficacy. Relevant outcomes from baseline stool survey, treatment and follow-up were statistically evaluated in relation to area of residence (rural/urban), gender, age group (<11/≥years) and infection. Adherence to baseline survey was 81.2%, and prevalence of infection was 21.4%. Of the 539 positives, 60 (11.1%) had ≥400 eggs per gram of faeces (heavy-intensity infection). Prevalence of infection was significantly higher among rural residents and≥11year olds, whereas intensity of infection was higher among rural residents,≥11year olds and boys. Adherence by the positives to treatment was 93.3% and adherence by the treated children to 45-day follow-up was 72.2%. At 45days after treatment, 97.0% of the 363 children surveyed were egg-negative; the egg reduction rate was 99.4%. Of the 924 children who responded to the questionnaire, 95.5% showed awareness of schistosomiasis, although 76.2% reported contact with natural, unsafe bodies of water. Reported contact with water was significantly more frequent among infected than non-infected, and boys than girls. The results show persisting infection and risk behaviour among schoolchildren, regardless of their basic knowledge about schistosomiasis. These are grounds for implementing specific educational actions to improve awareness and behavioural change, jointly with other control measures, to attain the MoH goals.

School-based and community-based actions for scaling-up diagnosis and treatment of schistosomiasis toward its elimination in an endemic area of Brazil.

This study evaluated a school-based and a community-based scheme for diagnosis, treatment and follow-up of schistosomiasis mansoni among school-aged children in views of resolution CD49.R19 of the Pan American Health Organization toward the elimination of schistosomiasis as a public health problem in the Americas and subsequent commitments endorsed by the Brazilian government. The school-aged population from a representative municipality of the endemic area of Northeastern Brazil was randomly allocated to either school-based or community-based scheme. The two schemes were compared with regard to coverage of diagnosis by the Kato-Katz method (KK) at baseline, treatment of the positives for Schistosoma mansoni with praziquantel, treatment of the positives for soil-transmitted helminthes (STH) with mebendazole, as well as follow-up of treatment efficacy and reinfection assessed respectively at four and 12 months after treatment. Nutritional status of the positives for S. mansoni was assessed at baseline and re-assessed at 12 months after treatment. Coverage of diagnosis and treatment was satisfactory (>75%) in both schemes. Diagnosis coverage at baseline and at 12 months was significantly higher in the community scheme, whereas treatment coverage did not differ significantly between the two schemes either at baseline or at 12 months. The number of children covered per day was significantly higher in the schools than in the community at baseline but not at follow-up, when daily coverage was higher in the community. With regard to S. mansoni, overall treatment efficacy rate at four months was 90.8%, and reinfection rate at 12 months was 21.6%. For STH, overall treatment efficacy was 45.4% and reinfection, 32.8%. The nutritional status of the positives for S. mansoni at baseline did not change significantly at 12 months post-treatment. Actions targeted at this particularly vulnerable high-risk group should combine school-based and community-based interventions as well as preventive measures to reduce transmission.

Aspectos bionômicos de Squamatoides trivittatus (Diptera, Sarcophagidae) sob condiçöes de laboratório / Bionomical aspects of the Squamatoides trivittatus (Diptera, Sarcophagidae) under laboratory conditions

Experiments with Squamatoides trivittatus were carried out in two different controlled temperatures (16ñ1§C/50-60 per cent RH and 27ñ1§C/70-80 per cent RH). The viability of larvae and pupae at 27§C was 89.82 per cent and 92.75 per cent respectively. Larvae did not develop at 16§C. Larval development lasted for 20ñ4hr, 16ñ8 hr and 60ñ7 hr for the first, second and third instars, respectively, completing a total of 96ñ6 hr. The mean pupal period lasted for 15.7ñ1.6 days. In longevity tables for the adults, life-expectancy for 50 per cent of the colony submitted to 16§C was of 1.78 weeks for males and 2,42 for females. At 27§C a life-expectancy of 1.15 weeks for males and 0.78 week for females was recorded. The average life-spans for males and females at 16§C were 3.5ñ2.0 and 3.8ñ2.6 weeks, respectively, and 1.9ñ1.2 weeks for both sexes. At 27ñC, the longevity recorded was of 2.1ñ1.3 weeks for males and 1.7ñ1.1 week for females.