Work on Neglected Tropical Diseases in Brazil provides lessons for the Africa region

By Russell Stothard Brazil has a significant burden of Neglected Tropical Diseases (NTDs) but these often differ to those in sub-Saharan Africa. For example in Brazil, there are no tsetse flies and thus there can be no transmission of human sleeping sickness. However, other blood sucking insects abound and in rural areas, triatomine bugs act as the principal vectors of Chagas disease, a major blight throughout South America and is the leading cause of heart failure. Infection with this single-celled parasite is typically chronic and drug treatment is largely ineffective when the disease progresses towards its later stages, where nearly all muscle tissues can be parasitized. Several years ago when working at the London School of Hygiene of Tropical Medicine with Professor Michael Miles, we showed that the parasite Trypanosoma cruzi underwent sexual reproduction in such tissues highlighting its capacity for  rapid evolution within the body. Of the early leading names in tropical medicine, two researchers Oswaldo Cruz and Evandro Chagas, are not as well-known in Europe as they should be, both being eclipsed perhaps by Patrick Manson and Ronald Ross. Nonetheless, Cruz and Chagas have left a truly impressive legacy in Brazil with the FIOCRUZ which is celebrating its 115 anniversary. Today FIOCRUZ employs over 11,000 staff and maintains a highly-regarded hospital and conducts an impressive portfolio of applied health research from the production of vaccines, drugs, reagents and diagnostic kits to education and training and engagement with its many social programmes focused on disease control. Within the UK we have much to learn from the approach taken by the foundation on how integrated control can proceed across a range of areas of health.

Carlos Chagas and team

Charlos Chagas with his team (Fernando’s grandfather is in the middle row on the right-hand side)

Being a speaker at ARTHROMINT 2015 meant I had the good fortune to visit the FIOCRUZ castle and see first-hand the library where Cruz and Chagas once worked. The history really does seep from its walls as I learnt from my hosting colleague Dr Fernando Monteiro, who works on the molecular systematics of Triatomines, that his grandfather was part of Chagas’s team and that his family has maintained a long connection with the institute. Having also worked on triatomine bugs before, it was a pleasure to give my research seminar at the institute and highlight more recent work on schistosomiasis and the implementation research that COUNTDOWN will conduct on several other NTDs, that often parallels similar challenges in Chagas disease control.

Speaking about schistosomiasis in Brazil is highly appropriate, for intestinal schistosomiasis is a major health hazard in rural populations where water hygiene and sanitation is poor. There is also a longstanding national control programme also focused on curative treatment with praziquantel (PZQ), however, there are key differences in approach when compared to those in Africa. Foremost, PZQ treatment is given out on a selective basis rather than in community-wide programmes. Hence, for a child to receive treatment (s)he must be shown to have evidence of infection upon the occurrence of schistosome eggs, the frontline diagnostic being the Kato-Katz stool examination in a ‘test and treat’ strategy.

Whilst this classic parasitolological method is also used in Africa, the necessary man-power and resources within the health system to provide this service to each child annually is outside the reach and resources of many Ministries of Health. Hence only community-wide application is possible or recourse is needed to more field-friendly diagnostic methods such as rapid urine antigen tests. Discussions with Octavio Pieri, the Brazilian national control programme co-ordinator, demonstrated a range of experiences in the Brazilian programme which it is important to share across the Africa region. Themes emerged such as the need for better PZQ dosing, treatment of marginalised groups (e.g. pregnant women and preschool children) and cross-talk with health education and water sanitation sectors. ARTHROMINT 2015 was a great success and I now look forward to discussing further in August how schistosomiasis control programmes can be optimised, especially in promoting access to PZQ in young children, across the transition from control to elimination settings.

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