Prevalence of schistosomiasis and soil-transmitted helminth infections among schoolchildren in Burkina Faso.

To determine the current status of schistosomiasis and soil-transmitted helminth (STH) infections among schoolchildren after 10 years of mass treatment with praziquantel. Parasitological surveys were conducted in 2013 in 22 primary schools located in 11 regions of Burkina Faso. Urine filtration methods and Kato-Katz techniques for stool were used to detect the eggs of Schistosoma hæmatobium, Schistosoma mansoni, and STH. 3514 schoolchildren aged from 7 to 11 (1.415 ± 9) years participated in the study. The prevalence of S. hæmatobium was 8.1% and of S. mansoni, 1.2%. The prevalence of intestinal schistosomiasis ranged from 0.6% to 26.2% and that of urinary schistosomiasis from 0.6% to 56.2%. The prevalence of hookworms was 1.1%, Ascaris lumbricoides 0.1%, and Trichuris trichiura 0.06%. The arithmetic mean of S. hæmatobium and S. mansoni were respectively 6 eggs/10 mL and 1.07 epg (eggs per gram). The arithmetic means of eggs were 0.07 epg, 0.03 epg, and 1.89 epg respectively for A. lumbricoides, T. trichiura, and Ankylostoma spp. This study shows the current situation for schistosomiasis and STH infections in different regions of Burkina Faso. Elimination of this parasitic disease requires the inclusion of other control methods, in addition to mass treatment.

H3Africa AWI-Gen Collaborative Centre: a resource to study the interplay between genomic and environmental risk factors for cardiometabolic diseases in four sub-Saharan African countries.

Africa is experiencing a rapid increase in adult obesity and associated cardiometabolic diseases (CMDs). The H3Africa AWI-Gen Collaborative Centre was established to examine genomic and environmental factors that influence body composition, body fat distribution and CMD risk, with the aim to provide insights towards effective treatment and intervention strategies. It provides a research platform of over 10 500 participants, 40-60 years old, from Burkina Faso, Ghana, Kenya and South Africa. Following a process that involved community engagement, training of project staff and participant informed consent, participants were administered detailed questionnaires, anthropometric measurements were taken and biospecimens collected. This generated a wealth of demographic, health history, environmental, behavioural and biomarker data. The H3Africa SNP array will be used for genome-wide association studies. AWI-Gen is building capacity to perform large epidemiological, genomic and epigenomic studies across several African counties and strives to become a valuable resource for research collaborations in Africa.

Enzyme-linked immunosorbent assay with worm vomit and cercarial secretions of Schistosoma mansoni to detect infections in an endemic focus of Burkina Faso.

Cercariae and adult Schistosoma mansoni were used to prepare, respectively, cercarial secretions (CS) and worm vomit (WoV). These were used as antigens in an enzyme-linked immunosorbent assay (ELISA) to test the IgG-reactivity of sera obtained in an S. mansoni-endemic area of Burkina Faso. Among the egg-excreting individuals (n = 240), 94.6% reacted positively with WoV, but only 62.9% with CS, thus suggesting a high diagnostic sensitivity of WoV, but not of CS. Among those individuals without detectable eggs in two Kato-Katz thick smears from different stool specimens (n = 215), the respective percentages of positive IgG reactivity were 78.1% and 63.3%. These positive reactions in the absence of detectable eggs are interpreted in terms of limited sensitivity of parasitological stool examinations. Optical density values in ELISA with CS, but not with WoV, correlated negatively with age, which may reflect decreasing exposure to cercariae in older individuals.

[Recent evolution of schistosomiasis in the water project of Sourou in Burkina Faso]. / Evolution récente des schistosomoses dans le complexe hydroagricole du Sourou au Burkina Faso.

In order to help the hydro-agricultural projects in the management of water resources together with a schistosomiasis control programme, it is important to evaluate the extent of the problem. This is the reason why parasitological and clinical surveys were conducted in schools associated with malacological surveys in transmission sites of several water projects including the one from Sourou. The data-collecting for the research on molluscs was carried out in surface water and as for parasitologic investigations on school-aged children, urine filtration and Kato-Katz were used to evaluate the parasitic load. The levels of prevalence were respectively in Guiédougou, Niassan, Di and Toma-île, in 2000, 60.5%, 40%, 48.8% and 51.9% for the urinary schistosomiasis, 5.3%, 0%, 6.9% and 50.6% for the intestinal schistosomiasis and in 2002, 56%, 51.9%, 51.6% and 43.4% for the urinary schistosomiasis, 10.1%, 8.2%, 22.7% and 90.8% for the intestinal schistosomiasis. The molluscs species collected and identified were: Biomphalaria pfeifferi for the intestinal schistosomiasis and Bulinus truncatus rohlfsi and B. senegalensis for the urinary schistosomiasis. B. senegalensis and B. truncatus were found naturally infested by S. haematobium. Water projects constitute amplifying factors of the proliferation of the species and parasitic exchange. All the actors (developers, populations, scientists) are questioning the means at their disposal to reduce the development of schistosomiasis which decrease the expected benefit of hydro-agricultural installations.

[Parasitological profile of urinary schistosomiasis of the Sourou hydroagricultural complex of Burkina Faso]. / Profil parasitologique de la schistosomose urinaire du complexe hydroagricole du Sourou au Burkina Faso.

In the Sourou area of Burkina Faso, parasitological and malacological surveys of urinary schistosomiasis have been carried out in the constructed sites of Guédougou, Niasan and Débé dating respectively from 1967, 1986 and 1996. The investigations covered also the traditional villages of Lanfiera, Di, Poro, Tiao and Mara situated in the middle of the hydroagricultural planning for the first, very close to the lake for the second and about twenty kilometres distant for the three last. These towns represent the main sites in the Sourou area. The results of the parasitological surveys showed that urinary schistosomiasis was present in all sites. The levels of prevalence varied considerably: 70.3% in Guiédougou, 40.8% in Niassan, 8.5% in Débè in the irrigated zone, 55.6% in Lanfiéra, 56.8% in Di, 13.2% in Poro, 83.3% in Tiao and 64.7% in Mara. Concerning the malacological investigation, two species (Bulinus senegalensis and B. truncatus) were shown to be intermediate hosts of Schistosoma haematobium. The first was endemic to the area while the second was compatible with S. haematobium from the Sourou and other zones. Compared to the results of earlier investigations, the endemic had worsened with differences according to sites. This disparity of prevalence levels which has already been observed in other hydroagricultural area results from many factors, among which the impact of irrigation activities, the aquatic biotope system (irrigation canals, natural lake, pools and temporary rivers) and the type of contact of human communities with water rank high. Schistosomiasis expansion is amplified by the intermediate host dynamics and the introduction of new schistosomes carried by the new workers arriving from all over the country. In these conditions, in order to reduce rapidly prevalence levels, preventive measures should be centred on chemotherapy for the population. The treatment should be administered during a period of weak intermediate host density and be directed towards in-coming workers. Such an approach should be able to check the spread of schistosomiasis naturally occurring with the irrigation of new sites.