Mortality in Captive Rhesus Monkeys (Macaca mulatta) in China Due to Infection with Yersinia pseudotuberculosis Serotype O:1a

Yersinia pseudotuberculosis in Non-Domesticated Mammals and Birds in Captivity

Yersinia pseudotuberculosis causes yersiniosis in a wide range of mammalian and avian taxa worldwide. This review aims to provide an overview of the current literature on yersiniosis in non-domesticated mammals and birds in captivity. Data on the prevalence of Y. pseudotuberculosis in captive populations are scarce. Transmission is primarily via the fecal-oral route, with wild rodents and birds as primary reservoirs. Predisposing factors to yersiniosis include young age, inclement weather, stress, and genetic factors. Symptoms are often non-specific, with sudden death occurring frequently, particularly in avian species. Gross pathological examination typically reveals multiple white-yellow foci in visceral organs, while histopathology demonstrates necrosis with central bacterial colonies. Ante-mortem diagnosis can be challenging as bacterial culture and isolation from fecal samples are often hindered by intermittent excretion and competition with other gastrointestinal flora. Although killed and subunit vaccine formulations have demonstrated limited protective efficacy, live attenuated strains may hold greater promise for inducing more robust and durable immunity. Y. pseudotuberculosis remains a significant threat to animal health, highlighting the need for faster and more reliable diagnostic techniques and the development of more effective treatment and prophylactic strategies.

YERSINIA PSEUDOTUBERCULOSIS INFECTIONS IN PRIMATES, ARTIODACTYLS, AND BIRDS WITHIN A ZOOLOGICAL FACILITY IN THE UNITED KINGDOM

Infection with Yersinia pseudotuberculosis can be difficult to diagnose and treat successfully. Twenty-four cases from the Zoological Society of London (ZSL) London Zoo and ZSL Whipsnade Zoo were identified between 2001 and 2019. Husbandry, medical, and postmortem records for six primates, 10 artiodactyls, and eight birds were reviewed to identify common clinical signs and gross lesions. Most cases occurred during the winter; however, an outbreak in four primates occurred during the summer following a period of stress associated with increased ambient noise and activity. Common clinical signs included lethargy (6/6 primates, 4/10 artiodactyls, 4/8 birds) or death without premonitory signs (3/10 artiodactyls, 4/8 birds). Once clinical signs were observed, disease progressed quickly. Poor condition was common in mammals (6/6 primates, 9/10 artiodactyls), but often went undetected until postmortem examination. Neurological signs occurred in three of six primates. Diarrhea and anorexia were uncommon in all animals. Hepatitis was observed in all groups (4/6 primates, 2/10 artiodactyls, 4/8 birds), mesenteric lymphadenomegaly was common in mammals (4/6 primates, 8/10 artiodactyls), and gastroenteritis was common in artiodactyls (7/10). Erythematous, punctate rashes, which have only been reported with yersiniosis in humans, were present in three of six primates. Bacterial cultures from the liver in primates and birds or enlarged mesenteric lymph nodes in artiodactyls were often diagnostic. All isolates were susceptible to marbofloxacin, oxytetracycline, streptomycin, ceftazidime, amoxicillin clavulanic acid, trimethoprim sulfamethoxazole, azithromycin, and doxycycline, and resistant to clindamycin. Histopathology and Perl's Prussian blue stains were performed on available liver samples (n = 18). Intracellular hemosiderin was present in 17 of 18 cases. Additional research is needed to determine if there is a relationship between hemosiderosis and yersiniosis.

Revised recommendations for health monitoring of non-human primate colonies (2018): FELASA Working Group Report

The genetic and biological similarity between non-human primates and humans has ensured the continued use of primates in biomedical research where other species cannot be used. Health-monitoring programmes for non-human primates provide an approach to monitor and control both endemic and incoming agents that may cause zoonotic and anthroponotic disease or interfere with research outcomes. In 1999 FELASA recommendations were published which aimed to provide a harmonized approach to health monitoring programmes for non-human primates. Scientific and technological progress, understanding of non-human primates and evolving microbiology has necessitated a review and replacement of the current recommendations. These new recommendations are aimed at users and breeders of the commonly used non-human primates; Macaca mulatta (Rhesus macaque) and Macaca fascicularis (Cynomolgus macaque). In addition, other species including Callithrix jacchus (Common marmoset) Saimiri sciureus (Squirrel monkey) and others are included. The important and challenging aspects of non-human primate health-monitoring programmes are discussed, including management protocols to maintain and improve health status, health screening strategies and procedures, health reporting and certification. In addition, information is provided on specific micro-organisms and the recommended frequency of testing.