Scientist at Work: Michael Muehlenbein
Everybody wants to hold the cute baby monkey, at least until Michael Muehlenbein informs the travelers who've paid thousands of dollars to get close to orangutans, macaques and other primates on the island of Borneo that all but one of the top dozen serious emerging diseases on the planet are zoonotic -- that is, diseases that originate from nonhuman animals.
You can believe that Muehlenbein, an assistant professor with Indiana University's Department of Anthropology, is doing you a favor when he kindly scolds, "There is rarely a good reason to hold a monkey."
From Honduras to Uganda and now to Borneo, where much of his current work on emerging infectious diseases related to human-wildlife contact is being conducted, Muehlenbein is among of group of scientists around the world conducting research that straddles a precipice between rare and endangered species protection and an oft-interconnected ecotourism that can play a significant economic role in developing but richly biodiverse countries like Malaysia.
More than half of all human infections have originated from other animals, and a number of pathogens -- simian/human immunodeficiency viruses, cryptosporidiosis, simian foamy virus, the primate malaria parasite Plasmodium knowlesi and simian T-lymphotropic virus -- have been transmitted from primates to humans. Primates in the wild also serve as reservoirs for human infectious diseases like yellow fever, filariasis and Chikungunya virus, Muehlenbein said.
"People are highly susceptible to a number of different infections, and because of the close genetic relatedness with humans, primates are particularly susceptible to human infections," he said. "To date, we've been relying on tourists to self-report vaccination status and current illnesses, and what we're finding is that people think they are healthier and better vaccinated than they actually are."
Couple that with what Muehlenbein and other scientists believe is an intrinsic unwillingness by some tourists to admit being sick or under-vaccinated after paying hefty sums for a trip to the remote wilds of Africa or Southeast Asia, and the precursors are in place for infectious disease transmission to occur. "Ecotourists and other travelers concerned about environmental protection are largely unaware of the impact they may directly have on animal health," he said.
In his most recent trips to the island of Borneo, Muehlenbein gathered about 650 respiratory samples from tourists to be used for viral and bacterial DNA and RNA extraction and identification. He also conducted extensive first-person surveys of tourists about their vaccination and personal wellness histories.
Described as the Sabah Ecosystem Health Project, Muehlenbein is monitoring human and animal health in and around the Lower Kinabatangan Wildlife Sanctuary and the Kabili-Sepilok Virgin Jungle Reserve. The ongoing work includes detailed descriptions of interactions between people and wildlife, as well as people's perceptions of wildlife, conservation, bushmeat usage and sanitation. His epidemiological survey of disease prevalence includes people (locals and tourists), wildlife (macaques, proboscis, orangutans, birds, bats and other small mammals), livestock, domestic pets and arthropods in and around those areas.
Back at IU Bloomington's new Evolutionary Physiology and Ecology Laboratory, which Muehlenbein directs atop Jordan Hall, a flow cytometry analyzer system is being used to conduct diagnostic assays in search of viruses and bacteria. Specific infectious organisms of interest include H1N1 swine influenza, respiratory syncytial virus, metapneumovirus, rhinovirus, adenovirus, Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila, Streptococcus pneumoniae, Neisseria meningitidis and others.
Following the surveys of more than 630 tourists at the Sepilok Orangutan Rehabilitation Centre in Sabah, Malaysia, Muehlenbein found that 15 percent of the group self-reported current symptoms of cough, sore throat, congestion, fever, diarrhea or vomiting, and that more than one in five reported having significant recent animal contact outside of the center. Also of note, and to be included in an upcoming paper in the journal Travel Medicine and Infectious Disease, is data showing that of that sample group, more than 70 of the tourists worked in medical related fields, yet only one-third had been vaccinated for influenza despite the majority hailing from temperate regions where influenza was more prevalent.
Muehlenbein will spend September gathering fresh data in the jungles around Sabah, which is located on the northwest coast of Malaysia. Part of the island of Borneo and nestled in the South China Sea with Indonesia, the Philippines and Vietnam as its closest neighbors, the Sepilok Orangutan Rehabilitation center at Sabah receives around 56,000 foreign visitors each year. It is also an area, he notes, that is being dramatically changed with the spread of oil-palm plantations.
"Human contact with wild orangutans and other species is increasing through population growth of indigenous peoples, increases in tourism, and most dramatically, by encroachment from oil-palm plantations and their workers," he said. "The goal is to accurately weigh the costs and benefits of increased human-animal contact."
Internationally, current reports confirm transmission of human respiratory syncytial virus and metapneumovirus to wild chimpanzees in Cote d'Ivoire, intestinal pathogens Giardia and E. coli to wild mountain gorillas and chimpanzees in Uganda, along with additional suspected transmissions of polio and pneumonia in chimps, measles in gorillas, scabies in gorillas and chimps, and yaws and schistosomiasis in baboons, Muehlenbein noted.
To help address these concerns Muehlenbein will join other members of the International Union for the Conservation of Nature in September in announcing the latest best practice guidelines for wild great ape tourism during the International Primatological Society's 23rd Congress in Kyoto, Japan. As a Primate Specialist Group member of IUCN's Species Survival Commission, Muehlenbein helped develop the new guidelines.
Muehlenbein came to IU in 2007 from the University of Wisconsin, where he was an assistant professor in the Department of Anthropology. He holds Ph.D. and master's degrees in biological anthropology from Yale and an MsPH in tropical medicine and biostatistics from Tulane University. He remains a research affiliate with the Center for Human and Primate Reproductive Ecology at Yale.
Here at IU Muehlenbein is also a core faculty member in the Program in International Studies, the Center for the Integrative Study of Animal Behavior, and the Anthropological Center for Training and Research on Global Environmental Change.
His research has been supported by National Science Foundation, the U.S. Fish and Wildlife Service, the IU Office of the Vice Provost for Research's Faculty Research Support Program and the American Society of Primatologists.