Interactions and Pathogen Transmission Between Carnivores in Madagascar

Introduced carnivores exert considerable pressure on native predators through predation, competition and disease transmission. Improved understanding of determinant factors of interactions and pathogen transmission between introduced and endemic wildlife may help to predict disease emergence, avoid pathogen spillover and help control outbreaks. Using non-invasive camera traps, I identified areas where transmission of pathogens might happen through records of shared space-use within a protected area in Eastern Madagascar. I showed that indirect interactions between animals were more likely to occur near the research station which may constitute a disease transmission hotspot for carnivores in the landscape. Secondly, I investigated the associations between individual and spatial variables with the exposure to pathogens in multiple sympatric endemic carnivores. I showed that individual characteristics such as age, sex and species are associated with exposure to Toxoplasma gondii, but not Leptospira spp. or Canine Parvovirus. Finally, I revealed where exchange of microbes has already occurred by using microbial genetics of Escherichia coli. Specifically, DNA fingerprinting methods were used to construct a microbial-sharing network between carnivores in the Betampona natural reserve ecosystem. Collectively, the results that are presented here may help the conservation efforts of the unique Malagasy carnivores by highlighting the need for disease monitoring and mitigation at the domestic animal and wildlife interface of Madagasca

Prévalence d’excrétion de Giardia et Cryptosporidium chez les humains, les animaux domestiques et les lémuriens de l’écosystème du Parc National de Ranomafana, Madagascar

L’augmentation des interactions entre humains et animaux sauvages en lisière des habitats naturels pourrait faciliter la transmission d’agents pathogènes entre les humains et les différentes espèces animales d’un écosystème et ainsi favoriser l’émergence de maladies. Nous avons effectué une étude transversale portant sur l’infection par Giardia et Cryptosporidium chez les humains, les animaux domestiques, les rongeurs et les lémuriens au sein de l’écosystème de Ranomafana, Madagascar. Des échantillons de fèces ont étés collectés de manière non invasive chez des personnes volontaires, des mammifères domestiques et des rongeurs introduits habitant trois villages situés en lisière du Parc National de Ranomafana (PNR) ainsi que quatre espèces de lémuriens (Propithecus edwardsii, Prolemur simus, Eulemur rubriventer et Microcebus rufus) du PNR. Des analyses coproscopiques par la technique d’immunofluorescence directe ont été réalisées afin de détecter la présence de Cryptosporidium et Giardia. Leur prévalence a été estimée et certaines variables reliées à l’infection par les parasites ont été identifiées. Cryptosporidium et Giardia ont été détectés avec une prévalence estimée à 22,9 % et 13,6 % respectivement chez les humains. La prévalence de ces deux parasites variait de 0 % à 60 % chez les animaux domestiques et les rongeurs au sein des villages. L’espèce hôte, l’âge ainsi que la co-infection par un autre protozoaire sont les seules variables associées à l’infection par Cryptosporidium et Giardia dans cet écosystème tandis qu’aucune association avec une coinfection par un ordre de nématode n’a été détecté. De plus, Cryptosporidium a été détecté chez 10,5 % des lémuriens du PNR. Cette étude documente pour la première fois la présence de Cryptosporidium chez deux espèces de lémuriens du PNR. Par contre, Giardia n’a pas été détecté dans les échantillons issus de lémuriens du PNR.Increasing human activities in the vicinities of natural habitats may facilitate the emergence and transmission of diseases between humans and domestic animals and wildlife species. We conducted a cross-sectional study investigating the prevalence of Giardia and Cryptosporidium, two ubiquitous and potentially zoonotic protozoan parasites in various populations of humans and animals from the Ranomafana National Park ecosystem (RNP), Madagascar. Fecal samples were obtained non-invasively from human volunteers, domestic animals and introduced rodents inhabiting three villages in the vicinity of the national park and from four species of free-ranging lemurs (Propithecus edwardsi, Prolemur simus, Eulemur rubriventer and Microcebus rufus) from the RNP. Samples were analyzed using the direct immunofluorescence technique. Prevalences of Giardia and Cryptosporidium were estimated and variables associated with infections by the protozoa were identified. Cryptosporidium and Giardia were detected with a prevalence of 22.9 % and 13.6 % in humans respectively. The prevalences of these two parasites varied from 0 % to 60 % in domestic animals and introduced rodents from the villages. Species, age category and co-infection with the other protozoan were significantly associated with the infection by Cryptosporidium and Giardia in this ecosystem, whereas coinfections by different helminths order were not significantly associated with Cryptosporidium or Giardia. Moreover, Cryptosporidium was detected in 10.5 % of lemurs sampled from the RNP. This study reports for the first time the occurrence of Cryptosporidium in two species of lemurs from the RNP. Giardia was not detected in fecal samples from lemurs inhabiting the RNP

Epidemiology of pathogenic enterobacteria in humans, livestock, and peridomestic rodents in rural Madagascar.

BACKGROUND: Among the families of enteric bacteria are globally important diarrheal agents. Despite their potential for zoonotic and environmental transmission, few studies have examined the epidemiology of these pathogens in rural systems characterized by extensive overlap among humans, domesticated and peridomestic animals. We investigated patterns of infection with Enterotoxigenic Escherichia coli, Shigella spp., Salmonella enterica, Vibrio cholerae, and Yersinia spp. (enterocolitica, and pseudotuberculosis) in Southeastern Madagascar where the potential for the aforementioned interactions is high. In this pilot project we conducted surveys to examine behaviors potentially associated with risk of infection and if infection with specific enterobacteria species was associated with diarrheal disease. METHODOLOGY/PRINCIPAL FINDINGS: PCR was conducted on DNA from human, livestock, and rodent fecal samples from three villages. Overall, human prevalence was highest (77%), followed by rodents (51%) and livestock (18%). Rodents were ∼2.8 times more likely than livestock to carry one of the bacteria. The incidence of individual species varied between villages, with the observation that, E. coli and Shigella spp. were consistently associated with co-infections. As an aggregate, there was a significant risk of infection linked to a water source in one village. Individually, different pathogens were associated with certain behaviors, including: those who had used medication, experienced diarrhea in the past four weeks, or do not use toilets. CONCLUSIONS/SIGNIFICANCE: Different bacteria were associated with an elevated risk of infection for various human activities or characteristics. Certain bacteria may also predispose people to co-infections. These data suggest that a high potential for transmission among these groups, either directly or via contaminated water sources. As these bacteria were most prevalent in humans, it is possible that they are maintained in humans and that transmission to other species is infrequent. Further studies are needed to understand bacterial persistence, transmission dynamics, and associated consequences in this and similar systems

Summary of significant findings for infection with Enterobacteriaceae in human, livestock, and rodent populations.

<p>Summary of significant findings for infection with Enterobacteriaceae in human, livestock, and rodent populations.</p

Prevalence of Enterobacteriaceae infection by subject and location.

<p>Prevalence of Enterobacteriaceae infection by subject and location.</p

Incidence of each Enterobacteriaceae species in humans, livestock, and rodents by village.

<p>*Cattle and pigs.</p

Bacterial strains (positive controls), target genes, and primers^* used in this study.

<p>*All primer sequences and sensitivities obtained from Wang et al. (1997) except <i>Yersinia</i> obtained from Thoerner et al. (2003).</p>a<p>Product size with <i>Y. enterocolitica</i> serogroup 03 or 09 strains.</p>b<p>Product size with <i>Y. enterocolitica</i> serogroup 08 strains.</p

Risk factors for infection with Enterobacteriaceae in people living in villages in Southeast Madagascar.

<p>*Total n varies due to incomplete notation on some surveys or respondents do not participate in the given activity (e.g. tend livestock).</p><p><b>Bold</b>  =  statistically significant associations.</p