In this study, Dr Pierre Fongho provides the first insight into the current situation of bovine trypanosomiasis in the Cameroonian Far North region and on the potential mechanical vectors of animal trypanosomes four decades after elimination of the tse-tse fly.
Trapping tabanids by using Nzi trap in the Logon flood.
The Far North region of Cameroon is known as one of the most important drylands and livestock production zone in Lake Chad basin. It was a historical focus for animal trypanosomiasis until the early seventies, period coinciding with the eradication of tsetse flies, the biological vector. It is in view of these realities that Pierre Fongho Suh undertook such research in order to determine local pastoralists knowledge attitude and practice for trypanosomiasis. “The results of his researches confirmed the presence of Trypanosoma vivax, the most mechanically transmitted cattle trypanosomes, in the blood of the sampled animals, with a very low infection rate, suggesting an exaggeration of the disease importance by pastoralists” Dr Pierre said. However, “with the possibility that this low infection rate results from an effect of drug administered therapeutically to suspect cattle, the use of sentinels herds with Bovine Cerebral Theileriasis (BCT) for trypanosome detection is proposed as a workable approach for routine surveillance in the present context” he added.
Collection of blood from animal and Slides preparations and microscopic examination.
This investigation aimed at “detecting any sign of development of resistance to isometamedium”. Pierre Fongho claimed that “no protection failure against infection in the treated group was observed suggesting that this drug continues to have a good efficacy”. During his research on the field, he noticed that “pastoralists have a good knowledge of animal trypansomiasis and have developed responses to limit the challenge posed by tabanids. However, their accuracy in reporting trypanosomiasis cases is low. Moreover some of their practices represent an additional risk for diseases transmisison.” On the field, of all the hematophagous insects sampled, Atylotus agrestis was by far the most abundant potential vector of animal trypanosomes in the study region and probably the major contributor of all these insects to the transmission of animal trypanosomes in the study zone. Its abundance was highest in the Madiako canton, probably “because of the presence of a water body namely the Logone river. Moreover, tabanids seem to have a spatial preference for campsites” precise Dr Pierre Fongho.
Agropastoral villages visited in the Far North region of Cameroon.
According to him, “the analyses showed that wings of Amynthas agrestis are polymorphic and are as diversified as those of T. taeniola suggesting that these two species have the same phenotypic plasticity propensity”. Contrary to expectations, “neither the climate nor the geographical distance influenced shape variations. The phenogram based on pairwise Procrustes distances showed a strong proximity among Ndiyam shinwa populations”. Additionaly, “the flood plain population was phenotypically different from the other population, suggesting that habitat type (flood plain or not) is responsible for the observed dissimilarities. Given that wing shape has a polygenic basis, differences among populations could result from polymorphisms in those genes”. He believes that further investigations, including genetic ones, will “necessarily provide a comprehensive understanding of the wing variability”. For the future, the next step of this work will include to “determine the pathogens transmitted by tabanids to livestock in pastoral land of the Far North region; determine the genetic population structure of tabanids of the pastral zones of the Far north region and verify the existence of geographical populations”. But before reaching such future goals, Dr Pierre Fongho Suh recommended to the Regional Delegation for Ministry of Livestock, Fisheries and Animal husbandry, “a periodic surveillance of animal trypanosomiasis and sensitization of pastoralists on the use of veterinary drugs”.
