Integrated community-based intervention for urinary schistosomiasis and soil-transmitted helminthiasis in children from Caxito, Angola

Abstract

Background Schistosomiasis and soil-transmitted helminths (STH) infections are major public health problems. We aimed to study the 6-mo impact of mass drug administration with praziquantel and albendazole on urinary schistosomiasis and STH. Methods We examined children (aged 2–15 y) from one hamlet, who provided urine and faeces samples at baseline (n=197), 1 mo (n=102) and 6 mo (n=92); 67 completed the protocol. Results At baseline, 47/67 (70.1%) children presented Schistosoma haematobium (75.8% in the baseline total sample) and 12/67 (17.9%) with STH (30.5% in the initial sample, p=0.010). Among the children, 47.3% had heavy Schistosoma haematobium infection. The most frequent STH was Trichuris trichiura in 9.0%. We also found Hymenolepis nana (13.2%) and Plasmodium falciparum (9.1%) infections and anaemia (82.1%). One mo after chemotherapy there was a significant (p=0.013) reduction of Schistosoma haematobium prevalence (23.5%) and a high egg reduction rate (86.9%). Considering the sample of 67 children, the mean egg concentration was 498 at baseline, 65 at 1 mo and 252 at 6 mo (p<0.05). We also observed a reduction in STH infections, 50% in Ascaris lumbricoides, 33.3% in T. trichiura and 50% in hookworms. At 6 mo, the prevalence of Schistosoma haematobium (76.1%) was similar to the baseline and the STH reduction was not significant. Conclusions Longitudinal studies have reported many losses in these settings, but we were able to show that mass drug administration for control of schistosomiasis and STH present low effectiveness, that reinfections occur rapidly and that stand alone anthelmintic therapy is not a sustainable choice.

Anemia in preschool children from Angola: a review of the evidence

“…22,23 In that area, the distribution of anemia was found to be heterogeneous and to be influenced by the distribution of malaria. Between 2012 and 2013, Lemos et al 24 tested a therapeutic intervention in children (with 2-15 years) from a highly Schistosoma haematobium endemic setting of that province in which the prevalence of anemia at the baseline was very high (76%). In the studied children, 76% had S haematobium, 31% had at least 1 soil-transmitted helminth, 10% had Hymenolepis nana, and 6.7% had Plasmodium falciparum.…”

“…The study also reports that, among the children followed, all anemia cases were infected with S haematobium. 24 Interventions with potential two reduce anemia implemented in Angola. Using the described methodology, we have documented only to interventional studies.…”

“…Using the described methodology, we have documented only to interventional studies. Lemos et al, 24 tested a therapeutic intervention in children (with 2-15 years) from a highly S haematobium endemic setting of that province in the Bengo province, between 2012 and 2013. In sum, authors reported low effectiveness in reducing infections when a mass administration of praziquantel was conjugated with albendazole and an antimalarial test-and-treat approach to malaria-infected children, describing that prevalence reductions 1 month after treatment were relevant for urogenital schistosomiasis and intestinal parasites, but that 6 months later the prevalences were similar to the ones at the baseline.…”

“…In sum, authors reported low effectiveness in reducing infections when a mass administration of praziquantel was conjugated with albendazole and an antimalarial test-and-treat approach to malaria-infected children, describing that prevalence reductions 1 month after treatment were relevant for urogenital schistosomiasis and intestinal parasites, but that 6 months later the prevalences were similar to the ones at the baseline. 24 In addition, the variation in the prevalence of P falciparum was postulated to have been biased by the seasonality of malaria (which increased 1 month after treatment but decreased 6 months after), whereas the very high prevalence of anemia was observed to have nonsignificant reduction. 24 Those results reiterate the high prevalence of infections and anemia in Angola and suggest that the beneficial effect of exclusively therapeutic interventions may not be sustained in our setting, possibly due to heavy contaminated environments.…”

“…24 In addition, the variation in the prevalence of P falciparum was postulated to have been biased by the seasonality of malaria (which increased 1 month after treatment but decreased 6 months after), whereas the very high prevalence of anemia was observed to have nonsignificant reduction. 24 Those results reiterate the high prevalence of infections and anemia in Angola and suggest that the beneficial effect of exclusively therapeutic interventions may not be sustained in our setting, possibly due to heavy contaminated environments. On the contrary, the effectiveness of nutritionspecific interventions needs also to be further investigated.…”