Diseases in wild chimpanzees of the Taï National Park, Côte d Ivoire

Deckblatt-Impressum Inhaltsverzeichnis Abkürzungsverzeichnis Einleitung Literaturübersicht und Hintergrund Material und Methoden Ergebnisse Diskussion Ausblick Zusammenfassung Summary Anhang Literaturverzeichnis Danksagung Lebenslauf SelbständigkeitserklärungWenig ist bekannt über Vorkommen und Bedeutung von Krankheitserregern bei wild leben¬den Menschenaffen, während die Bedrohung der Tiere durch Krankheiten offensichtlich ist. In dieser Arbeit wurden über ein Jahr hinweg drei Gruppen von habituierten Schimpansen, die teilweise seit mehr als 17 Jahren unter menschlicher Beobachtung im Taï-Nationalpark (Côte d Ivoire) leben, gefolgt und systematisch Kot- und Urinproben gesammelt sowie Aufzeich¬nungen über klinisch auffällige Tiere angefertigt. Vier verstorbene Schimpansen und zwei Rote Stummelaffen wurden autopsiert und pathologisch begutachtet. Von zwei zusätzlichen Schimpansen konnten Muskelstücke gewonnen werden, wobei der Großteil dieser beiden Kadaver von Leoparden verzehrt worden war. Die Gewebeproben wurden in Zusammenarbeit mit dem Deutschen Primatenzentrum, Göttingen, histologisch untersucht. Die Proben der im Zeitraum der Felduntersuchungen verstorbe¬nen Tiere sowie einige zusätzliche Proben von Schimpansen, die vor überwiegend 2001 ver¬storben waren, wurden auf Infektionen mit verschiedenen Erregern akuter bzw. chroni¬scher Erkrankungen mit serologischen und molekularen Methoden untersucht. In sechs Fällen konnte anhand der molekularbiologischen Analysen sowie der pathologi¬schen und histologischen Beurteilung Bacillus anthracis als Todesursache identifi¬ziert werden. B. anthracis ist zwar in vielen Regionen Afrikas endemisch, wurde jedoch im Rahmen dieser Studie zum ersten Mal bei wild lebenden Menschenaffen diagnostiziert. Wo¬her der Erreger stammt und wie sich die Schimpansen infizieren konnten, wird Thema weite¬rer Studien sein. Des Weiteren konnte bei den Schimpansen neben anderen Viren eine ungewöhnliche Viel¬zahl unterschiedlicher STLV 1-Stämme festgestellt werden. Ein phylogenetischer Vergleich der Schimpansen-STLV 1-Stämme mit zwei Stämmen, die in Proben von Roten Stummel¬affen erfasst wurden, zeigte, dass Stämme der Stummelaffen teilweise näher mit den Schim¬pansen-STLV 1 verwandt waren als Stämme der Schimpansen untereinander. Da Schim¬pansen regelmäßig Rote Stummelaffen jagen und verzehren, kann hier eine Transspezies-Übertragung von STLV 1 von Beute auf Räuber postuliert werden. Auch Menschen in dieser und in vielen anderen Regionen Afrikas jagen und verzehren Affen; daher kann diese Trans¬spezies- Übertragung auch als Hinweis auf eine mögliche Übertragung auf den Menschen dienen und auf die Gefahren des Verzehrs von Affenfleisch hinweisen. Mit Hilfe eines modifizierten HTLV 1/2-Western Blots konnte die epidemiologische Verbrei¬tung von STLV 1 durch Antikörperbestimmung in Urinproben aller Mitglieder der 3 Schim¬pansengruppen untersucht werden. Derartige Untersuchungen ermöglichen, das Spektrum an neuen Erregern und Varianten bekannter Erreger abzuschätzen und damit sowohl einen Beitrag zum Schutz der bedrohten Menschenaffen als auch zum Erhalt der menschlichen Gesundheit zu leisten.While it is obvious that the survival of wild living primates is endangered, little is known about the prevalence of pathogens in these animals and their significance. In the present study three groups of habituated chimpanzees that had been living for more than 17 years under human observation in the Taï National Park (Côte d Ivoire) were observed and followed and samples of their feces and urine were collected systematically for 13 months. Also detailed observations of animals with clinical symptoms were recorded. Four dead chimpanzees and two western red colobus monkeys underwent autopsy and pathological examination. Samples of muscular tissue could be obtained from two additional chimpanzees although the main part of those two cadavers had been consumed by leopards. The tissue samples were investigated histologically in cooperation with the German Primate Center at Göttingen/Germany. Samples from individuals that had died within the time frame of the field studies were analysed for a range of pathogens causing acute or chronic diseases, as well as several additional samples from chimpanzees that had died before 2001 using serological and molecular methods. In six cases the cause of death could be identified unambiguously as an infection with Bacillus anthracis. While B. anthracis is endemic in many African regions, it was diagnosed for the first time in the context of the present study in wild-living primates. The question about the origin of the pathogen and the route of infection for these chimpanzees will be the focus of further studies. In addition to other viruses, an unusual diversity of different STLV 1 strains could be determined in the chimpanzees. A phylogenetic comparison of the chimpanzee STLV 1 strains with two strains that had been found in red colobus monkeys showed a closer relatedness of the colobus with the chimpanzee strains than that of the chimpanzee strains among each other. Since chimpanzees routinely hunt and consume red colobus monkeys, transspecies transmission of STLV 1 from prey to the hunter could be postulated. In these and other African regions, humans also hunt and consume monkeys, therefore such a transspecies transmission event might also suggest a possible transmission to humans and point towards the risks involved in consuming bushmeat from monkeys. Using a modified HTLV 1/2 Western Blot, the prevalence of STLV 1 could be investigated by determining the antibody status in urine samples from all members of the three chimpanzee groups. It becomes possible by such investigations to assess the range of emerging and variations of well-known pathogens and thereby to contribute to protect endangered primates as well as protect the health of the human population

A novel Coltivirus-related virus isolated from free-tailed bats from Côte d’Ivoire is able to infect human cells in vitro

Background: Zoonotic transmission events play a major role in the emergence of novel diseases. While such events are virtually impossible to predict, wildlife screening for potential emerging pathogens can be a first step. Driven by recent disease epidemics like severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and Ebola, bats have gained special interest as reservoirs of emerging viruses. Methods: As part of a bigger study investigating pathogens in African bats we screened animals for the presence of known and unknown viruses. Results: We isolated and characterised a novel reovirus from blood of free-tailed bats (Chaereophon aloysiisabaudiae) captured in 2006 in Côte d’Ivoire. The virus showed closest relationship with two human pathogenic viruses, Colorado tick fever virus and Eyach virus, and was able to infect various human cell lines in vitro. Conclusion: The study shows the presence of a coltivirus-related virus in bats from Sub-Sahara Africa. Serological studies could help to assess its impact on humans or wildlife health

Malaria parasite detection increases during pregnancy in wild chimpanzees

Background: The diversity of malaria parasites (Plasmodium sp.) infecting chimpanzees (Pan troglodytes) and their close relatedness with those infecting humans is well documented. However, their biology is still largely unexplored and there is a need for baseline epidemiological data. Here, the effect of pregnancy, a well-known risk factor for malaria in humans, on the susceptibility of female chimpanzees to malaria infection was investigated. Methods: A series of 384 faecal samples collected during 40 pregnancies and 36 post-pregnancies from three habituated groups of wild chimpanzees in the Tai National Park, Cote d'Ivoire, were tested. Samples were tested for malaria parasites by polymerase chain reaction (PCR) and sequencing. Data were analysed using a generalized linear mixed model. Results: Probability of malaria parasite detection significantly increased towards the end of pregnancy and decreased with the age of the mother. Conclusions: This study provides evidence that susceptibility to malaria parasite infection increases during pregnancy, and, as shown before, in younger individuals, which points towards similar dynamics of malaria parasite infection in human and chimpanzee populations and raises questions about the effects of such infections on pregnancy outcome and offspring morbidity/mortality

Discovery of herpesviruses in multi-infected primates using locked nucleic acids (LNA) and a bigenic PCR approach

Targeting the highly conserved herpes DNA polymerase (DPOL) gene with PCR using panherpes degenerate primers is a powerful tool to universally detect unknown herpesviruses. However, vertebrate hosts are often infected with more than one herpesvirus in the same tissue, and pan-herpes DPOL PCR often favors the amplification of one viral sequence at the expense of the others. Here we present two different technical approaches that overcome this obstacle: (i) Pan-herpes DPOL PCR is carried out in the presence of an oligonucleotide substituted with locked nucleic acids (LNA).This suppresses the amplification of a specific herpesvirus DPOL sequence by a factor of approximately 1000, thereby enabling the amplification of a second, different DPOL sequence. (ii) The less conserved glycoprotein B (gB) gene is targeted with several sets of degenerate primers that are restricted to gB genes of different herpesvirus subfamilies or genera. These techniques enable the amplification of gB and DPOL sequences of multiple viruses from a single specimen. The partial gB and DPOL sequences can be connected by long-distance PCR, producing final contiguous sequences of approximately 3.5 kbp. Such sequences include parts of two genes and therefore allow for a robust phylogenetic analysis. To illustrate this principle, six novel herpesviruses of the genera Rhadinovirus, Lymphocryptovirus and Cytomegalovirus were discovered in multi-infected samples of non-human primates and phylogenetically characterized

Assessing the feasibility of fly based surveillance of wildlife infectious diseases

Monitoring wildlife infectious agents requires acquiring samples suitable for analyses, which is often logistically demanding. A possible alternative to invasive or non-invasive sampling of wild-living vertebrates is the use of vertebrate material contained in invertebrates feeding on them, their feces, or their remains. Carrion flies have been shown to contain vertebrate DNA; here we investigate whether they might also be suitable for wildlife pathogen detection. We collected 498 flies in Taï National Park, Côte d’Ivoire, a tropical rainforest and examined them for adenoviruses (family Adenoviridae), whose DNA is frequently shed in feces of local mammals. Adenoviral DNA was detected in 6/142 mammal-positive flies. Phylogenetic analyses revealed that five of these sequences were closely related to sequences obtained from local non-human primates, while the sixth sequence was closely related to a murine adenovirus. Next-generation sequencing-based DNA-profiling of the meals of the respective flies identified putative hosts that were a good fit to those suggested by adenoviral sequence affinities. We conclude that, while characterizing the genetic diversity of wildlife infectious agents through fly-based monitoring may not be cost-efficient, this method could probably be used to detect the genetic material of wildlife infectious agents causing wildlife mass mortality in pristine areas

No evidence for transmission of SIVwrc from western red colobus monkeys (piliocolobus badius badius) to wild west african chimpanzees (pan troglodytes verus) despite high exposure through hunting

<p>Abstract</p> <p>Background</p> <p>Simian Immunodeficiency Viruses (SIVs) are the precursors of Human Immunodeficiency Viruses (HIVs) which have lead to the worldwide HIV/AIDS pandemic. By studying SIVs in wild primates we can better understand the circulation of these viruses in their natural hosts and habitat, and perhaps identify factors that influence susceptibility and transmission within and between various host species. We investigated the SIV status of wild West African chimpanzees (<it>Pan troglodytes verus) </it>which frequently hunt and consume the western red colobus monkey (<it>Piliocolobus badius badius</it>), a species known to be infected to a high percentage with its specific SIV strain (SIVwrc).</p> <p>Results</p> <p>Blood and plasma samples from 32 wild chimpanzees were tested with INNO-LIA HIV I/II Score kit to detect cross-reactive antibodies to HIV antigens. Twenty-three of the samples were also tested for antibodies to 43 specific SIV and HIV lineages, including SIVwrc. Tissue samples from all but two chimpanzees were tested for SIV by PCRs using generic SIV primers that detect all known primate lentiviruses as well as primers designed to specifically detect SIVwrc. Seventeen of the chimpanzees showed varying degrees of cross-reactivity to the HIV specific antigens in the INNO-LIA test; however no sample had antibodies to SIV or HIV strain - and lineage specific antigens in the Luminex test. No SIV DNA was found in any of the samples.</p> <p>Conclusions</p> <p>We could not detect any conclusive trace of SIV infection from the red colobus monkeys in the chimpanzees, despite high exposure to this virus through frequent hunting. The results of our study raise interesting questions regarding the host-parasite relationship of SIVwrc and wild chimpanzees in their natural habitat.</p

Non-Invasive Body Temperature Measurement of Wild Chimpanzees Using Fecal Temperature Decline

New methods are required to increase our understanding of pathologic processes in wild mammals. We developed a noninvasive field method to estimate the body temperature of wild living chimpanzees habituated to humans, based on statistically fitting temperature decline of feces after defecation. The method was established with the use of control measures of human rectal temperature and subsequent changes in fecal temperature over time. The method was then applied to temperature data collected from wild chimpanzee feces. In humans, we found good correspondence between the temperature estimated by the method and the actual rectal temperature that was measured (maximum deviation 0.22 C). The method was successfully applied and the average estimated temperature of the chimpanzees was 37.2 C. This simple-to-use field method reliably estimates the body temperature of wild chimpanzees and probably also other large mammals.Human Evolutionary Biolog

Detection of Retroviral Super-Infection from Non-Invasive Samples

While much attention has been focused on the molecular epidemiology of retroviruses in wild primate populations, the correlated question of the frequency and nature of super-infection events, i.e., the simultaneous infection of the same individual host with several strains of the same virus, has remained largely neglected. In particular, methods possibly allowing the investigation of super-infection from samples collected non-invasively (such as faeces) have never been properly compared. Here, we fill in this gap by assessing the costs and benefits of end-point dilution PCR (EPD-PCR) and multiple bulk-PCR cloning, as applied to a case study focusing on simian foamy virus super-infection in wild chimpanzees (Pan troglodytes). We show that, although considered to be the gold standard, EPD-PCR can lead to massive consumption of biological material when only low copy numbers of the target are expected. This constitutes a serious drawback in a field in which rarity of biological material is a fundamental constraint. In addition, we demonstrate that EPD-PCR results (single/multiple infection; founder strains) can be well predicted from multiple bulk-PCR clone experiments, by applying simple statistical and network analyses to sequence alignments. We therefore recommend the implementation of the latter method when the focus is put on retroviral super-infection and only low retroviral loads are encountered