Diversity of tsetse flies and trypanosome species circulating in the highly infested cattle rearing area of the Faro and Deo subdivision, Adamawa region, Cameroon.

Animal African Trypanosomiasis (AAT) remains an animal health problem in sub-Saharan Africa and in Cameroon in particular. Despite more than 40 years of fighting against AAT in some tsetse infested areas, the disease prevalence is still a concern. Improving the control strategies in different settings requires to understand the current epidemiological situation of AAT. The aim of the present study was to update our knowledge on the diversity of tsetse fauna and trypanosome species in the tsetse infested area of Faro and Deo division, Adamawa region, Cameroon. Tsetse flies were caught using Vavoua trap in two villages and the apparent density per trap (ADP) were estimated. After morphological identification of tsetse fly species, flies were dissected and their midguts recovered. The presence of blood meal residues was recorded. Trypanosomes species were checked in the flies' midguts by microscopy followed by PCR method. The vertebrate taxa on which tsetse flies have taken blood meal were determined using the heteroduplex-PCR method. A total of 338 tsetse flies including 11 teneral flies (10 Glossina palpalis palpalis and 01 G. morsitans submorsitans) and 327 non-teneral were trapped in Mayo Lainde and Tchabal Mbabo. Amongst the caught tsetse flies, of the 327 non-teneral flies, 315 (96.3%) were G. p. palpalis, 8 (2.4%) were G. morsitans submorsitans and 4 (1.2%) G. fuscipes fuscipes. Trypanosome infections including Trypanosoma congolense forest (19.88%) and savanah (2.53%) "types", T. brucei s.l. (7.30%) and T. vivax (2.85%) were identified in 45.08% of non-teneral flies (32.38% for single infection and 12.70% for mixed infection). Amongst the 54 blood meals identified in tsetse midguts, 41% were from humans, 33% from cattle and 26% from other vertebrate hosts. About 51.9% of blood meals were found with various trypanosome species including 42.6% with T. congolense and 24% with T. brucei s.l. This study revealed the presence of three tsetse taxa and the circulation of four trypanosome taxa in villages of the Faro and Deo division. About 45% of captured tsetse fly are infected with trypanosome species causing AAT. Tsetse flies feed on humans, cattle and many other vertebrates. Strategies to eliminate the vectors must be improved to reduce the pathological impacts of trypanosome infections in this area.

TRIM5α 136Q, CCR5 Promoter 59029G And CCR264I Alleles Impact The Progression Of HIV In Children And Adolescents.

BACKGROUND: Children show various degrees of vulnerability regarding HIV infection and disease progression. This disparity presents challenges for the follow-up of infected children. Here we investigated reasons behind this variability focusing on some host-related HIV genes. METHODS: We screened 570 Cameroonian children and adolescents, aged 1 to 19 years old. Among them, 137 were followed over 4 years, from 2010 to 2015. Upon signing a proxy consent, children and adolescents were classified according to their age, CD4 count, viral load and clinical symptoms as long-term non-progressors (LTNP), slow progressors (SP) and rapid progressors (RP). Their blood was collected every 6 months and used for biological and host genetic polymorphism analyses. Five genes were genotyped: Trim5α (R136Q), CCR5 promoter 59029G, CCR2-64I, SDF 3'A and CCR5-Δ32. Exposed non-infected (HEU) and unexposed HIV negative children (HNEU) were recruited as control groups. RESULTS: Among the 5 genes studied, the protective allele of Trim5α (R136Q) was present in all LTNP and in 72.34% and 2.56% of SP and RP, respectively (p<0.0001). The CCR5 promoter 59029G/G was also more present in LTNP and SP than in RP (p=0.02; p=0.04). The protective CCR2-64I homozygous genotype was almost absent in all groups, only the heterozygous genotype was present with a significant difference between RP vs SP (p=0.0001), and SP vs LTNP (p=0.0002). The CCR2-∆32 was completely absent either as homozygous or heterozygous genotype. It was a monomorphic allele. SDF 3'A was almost present as homozygous wild-type genotype in our study population and was associated neither to disease acquisition nor to disease progression. CONCLUSION: Among the 5 genes described in the study, Trim 5α (R136Q), CCR5 promoter 59029G and CCR2V64I alleles were associated to the progression of HIV infection in children and adolescents.

Differential expression of Fas receptors (CD95) and Fas ligands (CD95L) in HIV infected and exposed uninfected children in Cameroon versus unexposed children.

INTRODUCTION: The number of HIV exposed uninfected (HEU) infants is increasing as vertical transmission is reducing. This subpopulation requires more investigations. This study aimed at comparing the expression level of soluble Fas receptors (FasR) and ligands (FasL) between HIV infected, HEU and unexposed children. METHODS: Eighty eight HIV-1infected, 86 HEU and 38 HIV unexposed children were recruited. Soluble FasR and FasL were measured in their plasma. Mann-Whitney U-Test was used to compare groups with 95% confidence. Spearman coefficient was used to test the correlation with CD4 and viral load (VL). RESULTS: Overall plasma levels of FasR were higher than that of FasL. The concentration of FasR and FasL were significantly higher in HIV-1 infected children in comparison to HEU and unexposed children. There was no difference in the plasma level of FasL in HIV infected compared to HEU children. A significant difference was observed between HIV infected children and HEU children (P=0.001) for the FasL. FasR were higher in both HIV infected and unexposed children compared to HEU children. There was a positive correlation (rs=+0.4; p=0.01) in ARV treated children between CD4 count and FasL concentration. Significant negative correlation (rs=-0.3; p=0.040) in ARV naïve children was observed between CD4 percentage and FasL. Significant and positive correlation (rs=+0.4; p=0.008) was observed between the VL and FasL in HIV infected, treated or not. CONCLUSION: HEU children differ from HIV infected and unexposed children as the level of FasL/R expression is concerned. HEU should be considered different from HIV unexposed although exempt from virus as some immune dysfunctions have been reported among them.

Identification of different trypanosome species in the mid-guts of tsetse flies of the Malanga (Kimpese) sleeping sickness focus of the Democratic Republic of Congo.

BACKGROUND: The Malanga sleeping sickness focus of the Democratic Republic of Congo has shown an epidemic evolution of disease during the last century. However, following case detection and treatment, the prevalence of the disease decreased considerably. No active survey has been undertaken in this focus for a couple of years. To understand the current epidemiological status of sleeping sickness as well as the animal African trypanosomiasis in the Malanga focus, we undertook the identification of tsetse blood meals as well as different trypanosome species in flies trapped in this focus. METHODS: Pyramidal traps were use to trap tsetse flies. All flies caught were identified and live flies were dissected and their mid-guts collected. Fly mid-gut was used for the molecular identification of the blood meal source, as well as for the presence of different trypanosome species. RESULTS: About 949 Glossina palpalis palpalis were trapped; 296 (31.2%) of which were dissected, 60 (20.3%) blood meals collected and 57 (19.3%) trypanosome infections identified. The infection rates were 13.4%, 5.1%, 3.5% and 0.4% for Trypanosoma congolense savannah type, Trypanosoma brucei s.l., Trypanosoma congolense forest type and Trypanosoma vivax, respectively. Three mixed infections including Trypanosoma brucei s.l. and Trypanosoma congolense savannah type, and one mixed infection of Trypanosoma vivax and Trypanosoma congolense savannah type were identified. Eleven Trypanosoma brucei gambiense infections were identified; indicating an active circulation of this trypanosome subspecies. Of all the identified blood meals, about 58.3% were identified as being taken on pigs, while 33.3% and 8.3% were from man and other mammals, respectively. CONCLUSION: The presence of Trypanosoma brucei in tsetse mid-guts associated with human blood meals is indicative of an active transmission of this parasite between tsetse and man. The considerable number of pig blood meals combined with the circulation of Trypanosoma brucei gambiense in this focus suggests a transmission cycle involving humans and domestic animals and could hamper eradication strategies. The various species of trypanosomes identified in the Malanga sleeping sickness focus indicates the coexistence of animal and human African Trypanosomiasis. The development of new strategies integrating control measures for human and animal trypanosomiasis may enable the reduction of the control costs in this locality.