Zoonotic diseases of primates

Zoonotic Gastroenteric Diseases of Exotic Animals

Exotic pet ownership has steadily increased over the last decade, and with increased numbers of these species in close contact with humans, the risk of gastrointestinal zoonoses has also increased. Non-typhoidal serovars of Salmonella enterica are one of the most prevalent and important zoonoses of exotic pets, and reptile and backyard poultry are common asymptomatic carriers of these bacteria. Outbreaks of reptile-associated salmonellosis have occurred yearly in the United States since 2019 but contact with backyard poultry has actually been associated with more Salmonella outbreaks in the United States than any other animal species to date.

High Prevalence of Dysfunctional Animal-Visitor Interactions in 225 Southeast Asian Zoos and Aquariums

Humans have long delighted in being entertained by captive wild animals. In zoos and aquariums, animal-visitor interactions allow visitors to experience direct or indirect contact with animals. Well-managed animal-visitor interactions can help zoos and aquariums contribute to their educational objectives by eliciting pro-conservation behaviours from visitors while providing good animal welfare for the animals involved. However, some interactions are dysfunctional because they cause physical and psychological harm to the animal and reinforce negative values and beliefs towards conservation. We aimed to assess how dysfunctional animal-visitor interactions are and whether accreditation by zoological associations reduced the number of such interactions. We visited Thai zoos in person and conducted online monitoring of facilities in Southeast Asia. We report 1165 animal-visitor interactions in nine Southeast Asian countries in 225 zoos and aquariums. Taking photos with animals ("selfies") and riding on animals were scored as the animal-visitor interactions that were the most dysfunctional. The number of animal-visitor interactions was not less in accredited zoos, and there was little difference among countries. Behaviour change needs to form a strategy for change, in addition to robust legislation and improved efforts by zoological associations to push members to maintain standards and mentor non-accredited facilities.

First Overview of Zoological Medicine on Iberian Countries

The role of veterinary doctors, particularly those dedicated to Zoological Medicine, is becoming increasingly relevant and essential within the One Health framework. Educational and employment opportunities in this field vary widely across Europe, prompting us to characterise the sector in Portugal and Spain. A survey was conducted, resulting in 169 valid responses from veterinarians. Respondents were characterised based on gender, age, work environment, the highest level of education, additional training, whether they attended zoological medicine classes at university and their perception of the adequacy of that training. Further factors included years of experience, the percentage of their work involving zoological medicine, sectors they work in, the types of animals they treat, their confidence in treating these animals, sources of information they use, and membership in relevant professional associations. Relationships between these variables were examined. The results describe Iberian professionals working with non-traditional pets, wildlife, and zoo animals. Notably, only half of these professionals had taken zoological medicine classes at university; among those, the majority felt they inadequately prepared them for their work. Given the findings, enhancing the training and resources available to these professionals is crucial to prepare them for their roles better.

PATHOLOGY OF SPIRURID INFECTION IN VERVET MONKEYS (CHLOROCEBUS PYGERYTHRUS) HOUSED IN A PRIMATE REHABILITATION CENTER

Spirurids, specifically the Rictularia, Chitwoodspirura, Streptopharagus, and Protospirura genera, have been reported to parasitize all nonhuman primate taxa. Spirurid pathogenesis in nonhuman primates has not been reported frequently; however, Protospirura muricola has been associated with serious gastric pathologies, including gastric perforation. This study was a retrospective study of 38 vervet monkey (Chlorocebus pygerythrus) necropsies performed in a primate sanctuary that houses captive orphaned or injured wild-born vervet monkeys. Individuals were categorized according to their age, sex, and body condition score to investigate the relationships between these factors and parasite presence. This study identified P. muricola in 47.37% of the necropsied carcasses. Regarding individual factors associated with P. muricola infection, no significant differences between males and females were observed; however, relationships between parasite presence and poor body condition and advanced host age were observed. Furthermore, one monkey death was potentially directly related to spirurid pathogenic action, because the individual showed gastric perforation.

Ecological, parasitological and individual determinants of plasma neopterin levels in a natural mandrill population

Investigating how individuals adjust their investment into distinct components of the immune system under natural conditions necessitates to develop immune phenotyping tools that reflect the activation of specific immune components that can be measured directly in the field. Here, we examined individual variation of plasma neopterin, a biomarker of Th1 immunity in wild mandrills (Mandrillus sphinx), who are naturally exposed to a suite of parasites, including simian retroviruses and malaria agents. We analyzed a total of 201 plasma samples from 99 individuals and examined the effect of sex, age, social rank, reproductive state and disease status on neopterin levels. We found higher neopterin concentrations in males than females, but were unable to disentangle this effect from possible confounding effects of retroviral infections, which affect nearly all adult males, but hardly any females. We further detected a non-linear age effect with heightened neopterin levels in early and late life. In addition, adult males that harbored very high parasitaemia for Plasmodium gonderi also showed high neopterin levels. There was no effect of social rank in either male or female mandrills, and no effect of female reproductive state. Taken together, these results indicate that plasma neopterin may prove useful to investigate individual variation in investment into specific immune components, as well as to monitor the dynamics of immune responses to naturally occurring diseases that elicit a Th1 immune response.

Macacine Herpesvirus 1 Antibody Prevalence and DNA Shedding among Invasive Rhesus Macaques, Silver Springs State Park, Florida, USA

We compiled records on macacine herpesvirus 1 (McHV-1) seroprevalence and, during 2015–2016, collected saliva and fecal samples from the free-ranging rhesus macaques of Silver Springs State Park, a popular public park in central Florida, USA, to determine viral DNA shedding and perform sequencing. Phylogenetic analysis of the US5 and US5-US6 intragenic sequence from free-ranging and laboratory McHV-1 variants did not reveal genomic differences. In animals captured during 2000–2012, average annual seroprevalence was 25% ± 9 (mean ± SD). We found 4%–14% (95% CI 2%–29%) of macaques passively sampled during the fall 2015 mating season shed McHV-1 DNA orally. We did not observe viral shedding during the spring or summer or from fecal samples. We conclude that these macaques can shed McHV-1, putting humans at risk for exposure to this potentially fatal pathogen. Management plans should be put in place to limit transmission of McHV-1 from these macaques.

Schistosoma mansoni and other intestinal parasitic infections in schoolchildren and vervet monkeys in Lake Ziway area, Ethiopia

Objective

To assess Schistosoma mansoni and other intestinal parasitic infections in schoolchildren and vervet monkeys (Chlorocebus aethiops) in Bochessa Village, Ziway, Ethiopia.

Results

Fecal specimens from selected schoolchildren and droppings of the vervet monkeys were collected and microscopically examined for intestinal parasites using the Kato-Katz thick smear and formol-ether concentration techniques. The prevalences of S. mansoni, Trichuris trichiura, Ascaris lumbricoides, Enterobius vermicularis, hookworms, Hymenolepis nana and Taenia species among the children were 35.7, 26.9, 24.1, 2.1, 2.1, 1.07 and 2.1%, respectively (by Kato-Katz) and 39.3, 36.1, 35.6, 2.9, 10.0, 4.3, and 2.9%, respectively (by formol-ether concentration). Prevalence of S. mansoni in vervet monkeys ranged from 10 to 20%. B. pfeifferi snails were exposed to S. mansoni miracidia from vervet origin, shed cercariae were then used to infect lab-bred albino mice. Adult worms were harvested from the mice 5 weeks post-exposure to cercariae to establish the schistosome life cycle and confirm the infection in the vervet monkeys. The natural infection of S. mansoni in vervet monkeys suggests that the non-human primate is likely to be implicated in the local transmission of schistosomiasis. Further epidemiological and molecular studies are needed to fully elucidate zoonotic role of non-human primate in the area.

Diseases Transmitted by Less Common House Pets

Beside dogs and cats, the most common pets worldwide, an increasing number of pocket pets and exotic pets are making their way to more and more households, especially in North America and Europe. Although many of these animals make appropriate pets, they also can be a source of many zoonotic diseases, especially in young children and immunocompromised individuals. Some of these diseases can be life threatening, such as rabies, rat bite fever, and plague. Some others are quite common, because of the frequency of the pathogens harbored by these species, such as salmonellosis in reptiles and amphibians. Appropriate knowledge of the zoonotic agents carried by these "new" pet species is strongly recommended prior to acquiring pocket or exotic pets. Furthermore, adopting wildlife as pets is strongly discouraged, because it is always a risky action that can lead to major health issues.

Selected Zoonoses

Human risks of acquiring a zoonotic disease from animals used in biomedical research have declined over the last decade because higher quality research animals have defined microbiologic profiles. Even with diminished risks, the potential for exposure to infectious agents still exists, especially from larger species such as nonhuman primates, which may be obtained from the wild, and from livestock, dogs, ferrets, and cats, which are generally not raised in barrier facilities and are not subject to the intensive health monitoring performed routinely on laboratory rodents and rabbits. Additionally, when laboratory animals are used as models for infectious disease studies, exposure to microbial pathogens presents a threat to human health. Also, with the recognition of emerging diseases, some of which are zoonotic, constant vigilance and surveillance of laboratory animals for zoonotic diseases are still required.