Xenomonitoring of sleeping sickness transmission in Campo (Cameroon)

Background: The sleeping sickness focus of Campo in South Cameroon is still active, at a low endemic level, for more than a century, despite a regular medical surveillance. The present study focuses on the spatial distribution of xenomonitoring information obtained from an entomological survey performed in the dry season 2012. It appears that humans constitute a third of the blood meals and that the flies' densities were coherent with those classically observed in the different biotopes. Paradoxically, the epicenter of the focus is the place where the risk indicators are the lowest ones. Methods: Particular attention was paid to the entomological device so that it covered the main part of human activities in the study area. One hundred and sixty-two pyramidal traps were used to catch tsetse flies twice a day that were identified, counted, dissected. Molecular analysis using classical and specific molecular markers was conducted to determine the importance of trypanosome infections and the nature of the feeding hosts. This information was used to calculate a Transmission Risk Index and to define a gradient of risk that was projected into a Geographical Information System. Results: Conventional entomological indicators such as species identification of tsetse flies or the Apparent Density per Trap per day, show that Glossina palpalis palpalis is the main species in the campo area which is classically distributed into the different biotopes of the study area. Molecular analysis reveals that humans constitute a third of the blood feeding hosts and that 20 % of the dissected flies were infected with trypanosomes, principally with Nannomonas. Nevertheless, one fly was carrying Trypanosoma brucei gambiense, the pathogen agent of sleeping sickness, showing that the reservoir is still active in the epicenter of the focus. Paradoxically, the Transmission Risk Index is not important in the epicenter, demonstrating that endemic events are not only depending on the man/vector contact. Conclusion: Xenomonitoring provides a valuable guide/tool to determine places at higher risk for vector/human contact and to identify trypanosomes species circulating in the focus. This information from xenomonitoring demonstrates that decision makers should include a veterinary device in a control strategy

No evidence for association with APOL1 kidney disease risk alleles and Human African Trypanosomiasis in two Ugandan populations:

Human African trypanosomiasis (HAT) manifests as an acute form caused by Trypanosoma brucei rhodesiense (Tbr) and a chronic form caused by Trypanosoma brucei gambiense (Tbg). Previous studies have suggested a host genetic role in infection outcomes, particularly for APOL1. We have undertaken a candidate gene association studies (CGAS) in a Ugandan Tbr and a Tbg HAT endemic area, to determine whether polymorphisms in IL10, IL8, IL4, HLAG, TNFA, TNX4LB, IL6, IFNG, MIF, APOL1, HLAA, IL1B, IL4R, IL12B, IL12R, HP, HPR, and CFH have a role in HAT

Influence of storage containers on the physicochemical and microbiological (biofilm formation) indices of drinking water sources

ABSTRACT Effect of surfaces of earthenware pots, glass, plastic and stainless steel containers on the physicochemical and bacteriological (biofilm formation) quality of borehole and atmospheric water stored for twelve days were determined using standard analytical and bacteriological techniques. Susceptibility of the bacterial isolates to different antibiotics was also determined using standard Kirby-Bauer agar disc diffusion procedures. The physicochemical parameters determined for borehole water sample were within WHO permissible standard while rain water sample recorded slightly higher values for NO3 -, and NO2 -(10.2 mgL -1 and 0.045 mgL -1 respectively) than WHO standards of 10 mgL -1 and 0.02 mgL -1 respectively. Biofilm bacterial communities from stored borehole water consisted of nine genera including Pseudomonas, Micrococcus, Klebsiella, Bacillus, Staphylococcus, Escherichia, Proteus, Serratia, and Enterobacter. The recovery rate of the various bacterial genera were 40% in earthenware pot, 80% in plastic, 70% in stainless steel and 60% of the genera were isolated from glass container for stored borehole water. Fewer bacterial genera were isolated from stored atmospheric water and these included Pseudomonas, Bacillus, Staphylococcus, Streptococcus and Yersinia. The isolates were recovered at the rates of 40%, 80%, 60% and 40% in earthenware pot, plastic, stainless steel and glass containers respectively. While Escherichia coli, Yersinia sp and Pseudomonas aeruginosa exhibited remarkable sensitivity to Septrin (30 μg), Ampicillin (30 μg), Augmentin (30 μg) and Nalidixic acid (10 μg) as evinced by clear zones of inhibition, Enterobacter sp, Klebsiella sp and Proteus sp were moderately sensitive to some of the tested antibiotics. Amongst the gram positive bacteria, Micrococcus sp was most sensitive to the various antibiotics. Although Staphylococcus aureus showed resistance to most of the tested antibiotics, it was sensitive to Erythromycin (30 μg) and Chloramphenicol (30 μg). It could be deduced from the above results that the physicochemical and bacteriological quality of stored water are affected by both the source of the water and type of storage vessel. Although the effect of the vessels are not definitive, the levels of pH, Mg 2+ , NO2 -, NO3 -and hardness are enhanced in water stored in earthenware pots. The isolation of antibiotic resistant bacteria from stored water is of public health concern, thus, drinking water should not be held in containers for more than a day or two. Citation: Udofia GE, Ofon UA, Asamudo NU, Ndubuisi-Nnaji UU (2015). Influence of storage containers on the physicochemical and microbiological (biofilm formation) indices of drinking water sources