A comparative molecular survey of malaria prevalence among Eastern chimpanzee populations in Issa Valley (Tanzania) and Kalinzu (Uganda).

BACKGROUND: Habitat types can affect vector and pathogen distribution and transmission dynamics. The prevalence and genetic diversity of Plasmodium spp. in two eastern chimpanzee populations-Kalinzu Forest Reserve, Uganda and Issa Valley, Tanzania-inhabiting different habitat types was investigated. As a follow up study the effect of host sex and age on infections patterns in Kalinzu Forest Reserve chimpanzees was determined. METHODS: Molecular methods were employed to detect Plasmodium DNA from faecal samples collected from savanna-woodland (Issa Valley) and forest (Kalinzu Forest Reserve) chimpanzee populations. RESULTS: Based on a Cytochrome-b PCR assay, 32 out of 160 Kalinzu chimpanzee faecal samples were positive for Plasmodium DNA, whilst no positive sample was detected in 171 Issa Valley chimpanzee faecal samples. Sequence analysis revealed that previously known Laverania species (Plasmodium reichenowi, Plasmodium billbrayi and Plasmodium billcollinsi) are circulating in the Kalinzu chimpanzees. A significantly higher proportion of young individuals were tested positive for infections, and switching of Plasmodium spp. was reported in one individual. Amongst the positive individuals sampled more than once, the success of amplification of Plasmodium DNA from faeces varied over sampling time. CONCLUSION: The study showed marked differences in the prevalence of malaria parasites among free ranging chimpanzee populations living in different habitats. In addition, a clear pattern of Plasmodium infections with respect to host age was found. The results presented in this study contribute to understanding the ecological aspects underlying the malaria infections in the wild. Nevertheless, integrative long-term studies on vector abundance, Plasmodium diversity during different seasons between sites would provide more insight on the occurrence, distribution and ecology of these pathogens

Fractal measures in activity patterns: Do gastrointestinal parasites affect the complexity of sheep behaviour?

International audienceGastrointestinal nematodes are known to be one of the most economically important parasites in livestock production. In order to test whether fractal analysis of behaviour can be used as a diagnostic tool for detection of infected animals, we investigated fractal patterns in the behavioural activity of domestic sheep (Ovis aries) in relation to strongylid infection. Temporal dynamics in activity patterns of 20 sheep were recorded at high resolutions using tri-axial accelerometer loggers attached to the neck of naturally infected subjects. We measured fractal dynamics in the resultant acceleration time series, divided into periods of activity and inactivity, using several fractal methods and tested the prediction that temporal complexity in the activity patterns of infected control sheep and experimentally dewormed sheep should differ. Detrended fluctuation analysis (DFA) revealed that sheep behaviour sequences were characterized by long-range correlations, meaning that acceleration fluctuations are not random but depend on long-term activity events. Generalized linear mixed models built to test for the effect of deworming on fractal estimates showed that the temporal organization of sheep activity varies with the status of strongylid infection. Our results indicate that sheep treated with anthelmintics exhibited a higher complexity in their activity sequences than parasitized sheep, suggesting that organizational patterns of their behaviour change with gastrointestinal parasite infection. Thus, we provide evidence for the potential utility of fractal methods in behavioural welfare monitoring

No impact of strongylid infections on the detection of Plasmodium spp. in faeces of western lowland gorillas and eastern chimpanzees

[Background] Although a high genetic diversity of Plasmodium spp. circulating in great apes has been revealed recently due to non-invasive methods enabling detection in faecal samples, little is known about the actual mechanisms underlying the presence of Plasmodium DNA in faeces. Great apes are commonly infected by strongylid nematodes, including hookworms, which cause intestinal bleeding. The impact of strongylid infections on the detection of Plasmodium DNA in faeces was assessed in wild, western, lowland gorillas from Dzanga Sangha Protected Areas, Central African Republic and eastern chimpanzees from Kalinzu Forest Reserve, Uganda. [Methods]Fifty-one faecal samples from 22 habituated gorillas and 74 samples from 15 habituated chimpanzees were analysed using Cytochrome-b PCR assay and coprological methods. [Results]Overall, 26.4% of the analysed samples were positive for both Plasmodium spp. and strongylids. However, the results showed no significant impact of intensity of infections of strongylids on detection of Plasmodium DNA in gorilla and chimpanzee faeces. [Conclusion]Bleeding caused by strongylid nematode Necator spp. cannot explain the presence of Plasmodium DNA in ape faeces

MOESM1 of A comparative molecular survey of malaria prevalence among Eastern chimpanzee populations in Issa Valley (Tanzania) and Kalinzu (Uganda)

Additional file 1. Plasmodium partial cytochrome b gene sequences obtained from GenBank and this study