Tuberculosis (TB) outbreak in a closed Aotus monkey breeding colony: Epidemiology, diagnosis and TB screening using antibody and interferon-gamma release testing

A call-to-action to assist in efforts to protect owl monkeys (Aotus spp.)

The majority of the 11 species of owl monkeys (Aotus spp.) have declining populations or are listed as data deficient. Deforestation due to agriculture, development, or logging poses threats to owl monkeys throughout their range. In some areas, Aotus are hunted for bushmeat or trapped for the wildlife trade. In Colombia, the country with the greatest number of Aotus species, owl monkeys are also threatened by civil unrest. To help combat these challenges, nonprofit organizations and field researchers in habitat countries have successfully implemented a variety of conservation projects such as censusing and monitoring owl monkey populations, establishing protected areas, reforesting degraded areas, filing lawsuits to protect wild populations, helping law enforcement with environmental regulation, and promoting environmental education. We highlight some of the conservation successes and suggest actions people around the world can take to contribute to these important efforts.

Diversity and prevalence of zoonotic infections at the animal-human interface of primate trafficking in Peru

Wildlife trafficking creates favorable scenarios for intra- and inter-specific interactions that can lead to parasite spread and disease emergence. Among the fauna affected by this activity, primates are relevant due to their potential to acquire and share zoonoses - infections caused by parasites that can spread between humans and other animals. Though it is known that most primate parasites can affect multiple hosts and that many are zoonotic, comparative studies across different contexts for animal-human interactions are scarce. We conducted a multi-parasite screening targeting the detection of zoonotic infections in wild-caught monkeys in nine Peruvian cities across three contexts: captivity (zoos and rescue centers, n = 187); pet (households, n = 69); and trade (trafficked or recently confiscated, n = 132). We detected 32 parasite taxa including mycobacteria, simian foamyvirus, bacteria, helminths, and protozoa. Monkeys in the trade context had the highest prevalence of hemoparasites (including Plasmodium malariae/brasilianum, Trypanosoma cruzi, and microfilaria) and enteric helminths and protozoa were less common in pet monkeys. However, parasite communities showed overall low variation between the three contexts. Parasite richness (PR) was best explained by host genus and the city where the animal was sampled. Squirrel (genus Saimiri) and wooly (genus Lagothrix) monkeys had the highest PR, which was ~2.2 times the PR found in tufted capuchins (genus Sapajus) and tamarins (genus Saguinus/Leontocebus) in a multivariable model adjusted for context, sex, and age. Our findings illustrate that the threats of wildlife trafficking to One Health encompass exposure to multiple zoonotic parasites well-known to cause disease in humans, monkeys, and other species. We demonstrate these threats continue beyond the markets where wildlife is initially sold; monkeys trafficked for the pet market remain a reservoir for and contribute to the translocation of zoonotic parasites to households and other captive facilities where contact with humans is frequent. Our results have practical applications for the healthcare of rescued monkeys and call for urgent action against wildlife trafficking and ownership of monkeys as pets.

Advancing tuberculosis diagnosis and management in cynomolgus macaques using Xpert MTB/RIF ultra assay

The detection and management of Mycobacterium tuberculosis complex (MTBC) infection, the causative agent of tuberculosis (TB), in macaques, including cynomolgus macaques (Macaca fascicularis), are of significant concern in research and regions where macaques coexist with humans or other animals. This study explored the utility of the Xpert MTB/RIF Ultra assay, a widely adopted molecular diagnostic tool to diagnose tuberculosis (TB) in humans, to detect DNA from the Mycobacterium tuberculosis complex in clinical samples obtained from cynomolgus macaques. This investigation involved a comprehensive comparative analysis, integrating established conventional diagnostic methodologies, assessing oropharyngeal-tracheal wash (PW) and buccal swab (BS) specimen types, and follow-up assessments at 3-month, 6-month, and 12-month intervals. Our results demonstrated that the Xpert MTB/RIF Ultra assay was able to detect MTBC in 12 of 316 clinical samples obtained from cynomolgus macaques, presenting a potential advantage over bacterial culture and chest radiographs. The Xpert MTB/RIF Ultra assay exhibited exceptional sensitivity (100%) at the animal level, successfully detecting all macaques positive for M. tuberculosis as confirmed by traditional culture methods. The use of PW samples revealed that 5 positive samples from 99 (5.1%) were recommended for testing, compared to 0 samples from 99 buccal swab (BS) samples (0.0%). In particular, the definitive diagnosis of TB was confirmed in three deceased macaques by MTB culture, which detected the presence of the bacterium in tissue autopsy. Our findings demonstrate that the implementation of the Xpert MTB/RIF Ultra assay, along with prompt isolation measures, effectively reduced active TB cases among cynomolgus macaques over a 12-month period. These findings highlight the advance of the Xpert MTB/RIF Ultra assay in TB diagnosis and its crucial role in preventing potential outbreaks in cynomolgus macaques. With its rapidity, high sensitivity, and specificity, the Xpert MTB/RIF Ultra assay can be highly suitable for use in reference laboratories to confirm TB disease and effectively interrupt TB transmission.

Specific identification of Mycobacterium bovis by Loop-Mediated Isothermal Amplification (LAMP) targeting the Region of Difference 12 (RD12) of the M. tuberculosis complex

Bovine tuberculosis is a prevalent zoonotic disease that causes high risks for production animals, dairy producers and consumers, together with significant economic losses. Thus, methods for easy, fast and specific detection of Mycobacterium bovis in small and medium-sized livestock under field conditions are very required. In this work, a Loop-Mediated Isothermal Amplification LAMP-PCR targeting the Region of Difference 12 (RD12) of M. bovis genome was designed for the purpose of identification. A set of six primers designed for the isothermal amplification of five different genomic fragments led to the specific identification of M. bovis from other mycobacterial species. A basic colorimetric reaction was clearly observed at first sight under natural light, indicating positive identification of M. bovis in a maximum of 30 min of isothermal amplification at 65 °C. The limit of detection was near 50 fg of M. bovis genomic DNA, corresponding approximately to 10 copies of the genome. •The proposed LAMP-PCR amplification of M. bovis genomic DNA might be performed by untrained laboratory personnel.•Specific identification of M. bovis LAMP is possible in 30 min at 65.. C using a simple water bath.•The basic colorimetric reaction for M. bovis identification could be observed with the naked eye under natural light.

An outbreak of tuberculosis in endangered northern pig-tailed macaques (Macaca leonina) and milu deer (Elaphurus davidianus) from a zoo in China

BACKGROUND

Tuberculosis (TB) is a zoonotic disease that affects humans and domesticated and wild animals. Animals in zoos are potentially an important source of TB for humans; however they are often neglected in routine disease surveillance programs. This investigation reports an outbreak of TB in milu deer and northern pig-tailed macaques in a zoo in Wuhan, China, which highlighted the need for improved prevention and control of TB in China.

METHODS

Between 24 November and 9 December 2020 two milu deer and a northern pig-tailed macaque that were displaying signs of wasting died. Post-mortem, histopathological diagnosis and acid fast staining were used for the dead animals. Multiple PCR for Mycobacterium tuberculosis complex (MTBC) was performed to identify the bacterial in both milu deer and northern pig-tailed macaque. The serum antibody iELISA for MTBC was then performed for all the surviving milu deer and northern pig-tailed macaques. Six seropositive milu deer and a seropositive northern pig-tailed macaque were subsequently euthanised and, along with two other dead milu deer, necropsied. DNA from these tissue samples was extracted and detected MTBC using PCR and Real-time PCR. Subsequently bacterial isolation was used to confirm the infection.

RESULTS

The lungs of the dead animals displayed gross and histological TB-like lesions and changes, and red staining bacilli were detected in smears of the lesions by microscopy after acid fast staining. Mycobacterium bovis (M. bovis) was detected in the two milu deer and Mycobacterium tuberculosis (M. tb) in the northern pig-tailed macaque using multiple PCR for MTBC. 35.3% surviving milu deer and 50% surviving northern pig-tailed macaques MTBC serologically positive. Six of the euthanised milu deer were also positive on a DNA test for M. bovis and the euthanised northern pig-tailed macaque was positive to M. tb.

CONCLUSIONS

This is the first report of tuberculosis in the endangered species, milu deer and northern pig-tailed macaques, in China, and warrants urgent attention by researchers and conservation authorities. These cases highlight the need for expanding surveillance for MTBC to zoos in China.

Mycobacterium tuberculosis sensu stricto in African Apes, What Is Its True Health Impact?

Since the Symposium on Mycobacterial Infections of Zoo Animals held at the National Zoological Park, Smithsonian Institution in 1976, our understanding of tuberculosis (TB) in non-domestic animals has greatly expanded. Throughout the past decades, this knowledge has resulted in improved zoo-habitats and facilities design, stricter biosecurity measures, and advanced diagnostic methods, including molecular techniques, that have significantly decreased the number of clinical disease caused by Mycobacterium tuberculosis in apes under human care settings. In the other hand, exponential growth of human populations has led to human encroachment in wildlife habitat which has resulted in increased inter-species contact and recurrent conflict between humans and wild animals. Although it is widely accepted that non-human primates are susceptible to M. tb infection, opinions differ with regard to the susceptibility to develop disease amongst different taxa. Specifically, some authors suggest that African apes are less susceptible to clinical tuberculosis than other species of primates. The aim of this review article is to evaluate the current scientific literature to determine the actual health impact of disease caused by Mycobacterium tuberculosis and more specifically Mycobacterium tuberculosis sensu stricto in African apes. The literature review included literature databases: Web of Science, Pubmed, Scopus, Wiley, Springer and Science direct, without temporal limit and proceedings of annual conferences in the field of wildlife health. Our general inclusion criteria included information about serological, molecular, pathological (macroscopic and/or microscopic), and clinical evidence of TB in African apes; while our, our more stringent inclusion selection criteria required that in addition to a gross pathology, a molecular test confirmed Mycobacterium tuberculosis sensu stricto as the cause of disease or death. We identified eleven reports of tuberculosis in African apes; of those, only four reports met the more stringent selection criteria that confirmed M. tb sensu stricto in six individuals. All reports that confirmed M. tb sensu stricto originated from zoological collections. Our review suggests that there is little evidence of disease or mortality caused by M. tb in the different species of African apes both under human care and free ranging populations. Additional studies are needed in free-ranging, semi-captive populations (sanctuaries) and animals under human care (zoos and rescue centers) to definitely conclude that this mycobacteria has a limited health effect in African ape species.

Tuberculosis detection in nonhuman primates is enhanced by use of testing algorithms that include an interferon-γ release assay

OBJECTIVE

To develop a testing algorithm that incorporates multiple assays to evaluate host cellular and humoral immunity and antigen detection concerning Mycobacterium tuberculosis complex (MTBC) infection in captive nonhuman primates.

ANIMALS

Cohorts of captive-bred and wild-caught macaques from 5 different geographic regions.

PROCEDURES

Macaques were tested for MTBC infection by use of a γ interferon tuberculosis (GIFT) assay, an interferon-γ release assay, and other assays. In the first 2 cohorts (n = 15 and 181), initial validation of the GIFT assay was performed by use of experimentally infected and unexposed control macaques. In the next 3 cohorts (n = 59, 42, and 11), results were obtained for opportunistically collected samples from macaques exposed during spontaneous outbreaks.

RESULTS

Sensitivity and specificity of the GIFT assay in the control cohorts were 100% and 97%, respectively, and were variable but enhanced by incorporating results from multiple assays in spontaneous outbreaks.

CLINICAL RELEVANCE

The detection and management of MTBC infection in captive nonhuman primate populations is an ongoing challenge, especially with animal imports and transfers. Despite standardized practices of initial quarantine with regular intradermal tuberculin skin testing, spontaneous outbreaks continue to be reported. Since infection encompasses a range of disease manifestations over time, a testing algorithm that incorporates multiple assays, such as the GIFT assay, to evaluate host cellular and humoral immunity in addition to agent detection is needed. Testing a combination of samples from controlled studies and spontaneous outbreaks of MTBC infection in nonhuman primates would advance the development and validation of a functional algorithm that incorporates promising tools such as the GIFT assay.

Hepatic lesions in captive owl monkeys (Aotus infulatus) with ultrasonographic "starry sky" liver

BACKGROUND

The "starry sky" (SK) liver is ultrasonographic pattern characterized by multiple hyperechogenic foci in hepatic parenchyma. The study aimed to characterize the microscopic hepatic lesions in captive owl monkeys with SK liver.

METHODS

Thirty-seven clinically healthy owl monkeys had their liver scanned and 18 of them had liver biopsy. Animals with SK and peliosis hepatis (PH) were subjected to immunohistochemical and molecular screening for Bartonella spp.

RESULTS

SK liver occurred in 59.4% (22/37) of the owl monkeys. Biopsied animals showed steatosis, hydropic degeneration, hemosiderosis, PH, and multifocal granulomatous hepatitis. Two monkeys had SK, granulomatous hepatitis, and PH which were negative for Bartonella spp.

CONCLUSIONS

PH and granulomatous hepatitis associated with hepatocellular degenerative lesions may present as hyperechoic nodular liver lesions consisted of SK liver; therefore, concomitant occurrence of two lesions or more contributed to the hepatic SK pattern among owl monkeys and such cases might be clinically monitored.

Research Relevant Conditions and Pathology in Nonhuman Primates

Biomedical research involving animal models continues to provide important insights into disease pathogenesis and treatment of diseases that impact human health. In particular, nonhuman primates (NHPs) have been used extensively in translational research due to their phylogenetic proximity to humans and similarities to disease pathogenesis and treatment responses as assessed in clinical trials. Microscopic changes in tissues remain a significant endpoint in studies involving these models. Spontaneous, expected (ie, incidental or background) histopathologic changes are commonly encountered and influenced by species, genetic variations, age, and geographical origin of animals, including exposure to infectious or parasitic agents. Often, the background findings confound study-related changes, because numbers of NHPs used in research are limited by animal welfare and other considerations. Moreover, background findings in NHPs can be exacerbated by experimental conditions such as treatment with xenobiotics (eg, infectious morphological changes related to immunosuppressive therapy). This review and summary of research-relevant conditions and pathology in rhesus and cynomolgus macaques, baboons, African green monkeys, common marmosets, tamarins, and squirrel and owl monkeys aims to improve the interpretation and validity of NHP studies.

Distinct epigenetic regulation in patients with multidrug-resistant TB-HIV co-infection and uninfected individuals

BACKGROUND

Mycobacterium tuberculosis (Mtb) is an airborne pathogenic microorganism that causes tuberculosis (TB). This pathogen invades lung tissues causing pulmonary infections and disseminates into other host organs. The Bacillus Calmette-Guérin (BCG) vaccine is employed to provide immune protection against TB; however, its efficacy is dependent on the age, immune status and geographic location of vaccinated individuals. Advanced diagnostic approaches such as GeneXpert MTB/RIF® and line probe assays (LPAs) have allowed rapid detection of drug-resistant, multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mtb strains. However, in sub-Saharan Africa, public and private health institutions are further burdened by the high prevalence of Human Immunodeficiency Virus (HIV), the causative agent of acquired immunodeficiency syndrome (AIDS) and TB co-infections across different age groups. Epigenetic mechanisms have been widely exploited by Mtb and HIV to bypass the host's innate and adaptive immune responses, leading to microbial proliferation and disease manifestation. In the current study, we investigated the impact of epigenetic mechanisms in regulating target gene expression in healthy and patients co-infected with MDR TB-HIV.

Mycobacterium tuberculosis var. tuberculosis infection in two captive black capuchins (Sapajus nigritus) in Southern Brazil

Tuberculosis is a common zooanthroponosis in humans with a high incidence in Brazil, but it may also affect non-human primates (NHPs), of which Old World primates are most commonly involved. Nonetheless, its occurrence in New World primates is unknown, and therefore, this study aimed to describe the infection by Mycobacterium tuberculosis variant tuberculosis in two captive black capuchin monkeys (Sapajus nigritus) in Southern Brazil. The primates were housed in the same enclosure, wherein close contact with humans frequently occurred, and presented apathy, anorexia, and death in a clinical course of 15 days to 2 months. At the necropsy, the tracheobronchial lymph nodes were markedly enlarged and firm to hard and on the cut surface had a caseous aspect. The lungs exhibited two injury patterns: multifocal and disseminated. Microscopically, the lungs exhibited multifocal to coalescing necrotic granulomas and non-necrotic granulomas, with multiple acid-fast bacilli within the cytoplasm of epithelioid macrophages and multinucleated giant cells. Bacilli were also labeled upon immunohistochemistry (IHC) for Mycobacterium tuberculosis. Microbiological culture of lung samples from both cases yielded colonies compatible with M. tuberculosis. The isolates were identified as M. tuberculosis var. tuberculosis through polymerase chain reaction (PCR). Although tuberculosis is poorly described in New World primates, M. tuberculosis var. tuberculosis may cause a highly contagious and progressive disease with high mortality in black capuchin monkeys (S. nigritus).

Interferon-Gamma test for the detection of Mycobacterium tuberculosis complex infection in Macaca mulatta and other non-human primates

We have formatted an assay to detect Mycobacterium tuberculosis complex infections of non-human primates. Commercially available reagents were used to elicit a specific immune response that was measured by interferon-gamma release. Initial evaluation using blood samples from Rhesus macaques experimentally infected with M tuberculosis distinguished infected versus uninfected animals.

Pulmonary actinomycosis in a free-living black-tufted marmoset (Callithrix penicillata)

Actinomycosis is a very rare infection in wild animals with a few reports in captive non-human primates. Herein we report a case of pulmonary actinomycosis in a free-living black-tufted marmoset in the urban area of the Federal District, Brazil. The animal presented severe dyspnea and died in the garden of a residence. At necropsy, the left-pulmonary lobes showed multiple nodules filled with purulent content. A myriad of beaded, branching, filamentous Gram-positive and modified Ziehl-Neelsen-negative bacilli arranged in aggregates or star-like colonies, surrounded by macrophages, neutrophils, and Splendori-Hoepli phenomenon were observed in histological sections of the lungs. According to the pathological findings and characteristic morphotintorial pattern of the infectious agent, pulmonary actinomycosis was diagnosed. Until now, fatal pulmonary actinomycosis had never been reported in free-living Simiiformes. Knowledge about the diseases that affect commensal free-range simians in urban areas forms the basis for actions aimed at conservation of the species.