5 research outputs found
Recommended from our members
Tuberculosis Infection in Free-Ranging Long-Tailed Macaques through Social Network and Modeling
This dissertation addresses the escalating threat of anthropozoonosis at human-wildlife interfaces by investigating the social dynamics of disease transmission among wildlife populations, focusing particularly on long-tailed macaques (Macaca fascicularis) inhabiting human-wildlife interface areas. Tuberculosis (TB) serves as the model infectious disease due to its high prevalence in Southeast Asia, air-borne transmission and its zoonosis nature. Although concerns about disease risks to these macaques have been raised, the role of individual variation, encompassing social network attributes and human exposures, has remained unexplored. To address these questions, this project utilizes non-invasive techniques for sample collection from a population of free-ranging macaques in Thailand. I adopt a network approach to examine the intricate relationship between social attributes and TB infection status. Furthermore, an epidemiological model, Susceptible-Exposed-Infectious-Recovered-Susceptible (SEIRS), is integrated to monitor changes in individuals' disease states and explore hypothetical scenarios of disease spread within social networks, with parameters tailored to each individual.Chapter One investigates the factors driving pathogen infection by identifying infected animals and examining how sociodemographic attributes, combined with interactions with conspecifics, humans, and responses to stress and sickness, influence TB infection patterns within social groups. Notably, it reveals that the likelihood of TB infection increases among individuals with high human interaction and those engaging in less grooming activity.
Chapter Two explores the influence of social network positions on TB transmission. By implementing a social network approach to locate infected individuals, this chapter explores the interplay between contact-transmission and social buffering. It highlights the significance of individual macaques' social network positions in their infection status, emphasizing that monkeys with fewer grooming interactions and living periphery are more likely to have TB.
Chapter Three employs mathematical modeling within the network to investigate transmission dynamics and the persistence of TB, taking into account variations in transmissibility and latency periods. SEIRS models reveal that over half of the population remains in the latent stage of TB infection. It elucidates that social buffering, specifically the adjustment of the latency period from latency to active TB, plays a pivotal role in explaining the presence of infected individuals in the social network periphery. In contrast, adjusting transmissibility fails to accurately represent observed relationships in this population.
Overall, this dissertation aims to uncover the social and demographic factors that influence the acquisition and transmission of TB among free-ranging long-tailed macaques inhabiting human-wildlife interface areas. Understanding the attributes of social network components in wildlife populations at the human-wildlife interface contributes to mitigating infectious disease transmission, reducing zoonotic risks, and promoting the well-being of both humans and wildlife. These insights play a crucial role in clarifying steps to prevent potential future pandemics
Non-invasive specimen collections for Mycobacterium tuberculosis detection in free-ranging long-tailed macaques (Macaca fascicularis).
Surveillance of infectious diseases in free-ranging or wild animals has been widely conducted in many habitat-range countries after the COVID-19 episode. Thailand is located in the center of the distribution range of long-tailed macaques (Macaca fascicularis; Mf) where the animals have both frequent human contact and a high prevalence of human tuberculosis. For the large-scale detection of Mycobacterium tuberculosis complex (MTBC) using IS6110-nested PCR in free-ranging Mf, non-invasive sampling was developed using oral (via rope bait) and fecal (direct swabs of fresh feces) specimen collection. Firstly, the MTBC-IS6110-nested PCR was validated in non-invasively collected specimens, in terms of its specificity and sensitivity, and then compared with those of the invasively collected oral and rectal swabs in 24 captive MTBC-suspected Mf. After validation, these methods were applied to survey for the prevalence of shed MTBC (MTBCS) in four previously reported MTBC-infected populations. A total of 173 baited rope specimens and 204 freshly defecated excretions were collected. The limit of detection of the IS6110-nested PCR technique was 10 fg/ÎŒL and the 181-bp PCR amplicon showed 100% sequence similarity with the MTB H37Rv genome sequence. Comparing the MTBCS detection between the invasive and non-invasive collected specimens in captive suspected Mf revealed a significant correlation between the two types of oral specimens (oral swabs and baited ropes; n = 24, r2 = 1, p-value < 0.001), but fresh fecal swabs showed higher MTBCS frequencies than the rectal swabs. Moreover, the proportion of MTBCS-positive free-ranging Mf were significantly higher in the fresh fecal swabs (8.82%; 95% CI; 4.9-12.7%) than in the baited ropes (5.20%; 95% CI; 1.9-8.5%). This result indicates that oral sampling via baited ropes and fecal sampling via defecated excretion swabs can serve as ancillary specimens for MTBCS detection in free-ranging non-human primates
Non-invasive specimen collections for Mycobacterium tuberculosis detection in free-ranging long-tailed macaques (Macaca fascicularis)
Surveillance of infectious diseases in free-ranging or wild animals has been widely conducted in many habitat-range countries after the COVID-19 episode. Thailand is located in the center of the distribution range of long-tailed macaques (Macaca fascicularis; Mf) where the animals have both frequent human contact and a high prevalence of human tuberculosis. For the large-scale detection of Mycobacterium tuberculosis complex (MTBC) using IS6110-nested PCR in free-ranging Mf, non-invasive sampling was developed using oral (via rope bait) and fecal (direct swabs of fresh feces) specimen collection. Firstly, the MTBC-IS6110-nested PCR was validated in non-invasively collected specimens, in terms of its specificity and sensitivity, and then compared with those of the invasively collected oral and rectal swabs in 24 captive MTBC-suspected Mf. After validation, these methods were applied to survey for the prevalence of shed MTBC (MTBCS) in four previously reported MTBC-infected populations. A total of 173 baited rope specimens and 204 freshly defecated excretions were collected. The limit of detection of the IS6110-nested PCR technique was 10 fg/ÎŒL and the 181-bp PCR amplicon showed 100% sequence similarity with the MTB H37Rv genome sequence. Comparing the MTBCS detection between the invasive and non-invasive collected specimens in captive suspected Mf revealed a significant correlation between the two types of oral specimens (oral swabs and baited ropes; n = 24, r2 = 1, p-value < 0.001), but fresh fecal swabs showed higher MTBCS frequencies than the rectal swabs. Moreover, the proportion of MTBCS-positive free-ranging Mf were significantly higher in the fresh fecal swabs (8.82%; 95% CI; 4.9â12.7%) than in the baited ropes (5.20%; 95% CI; 1.9â8.5%). This result indicates that oral sampling via baited ropes and fecal sampling via defecated excretion swabs can serve as ancillary specimens for MTBCS detection in free-ranging non-human primates
Recommended from our members
Impact of joint interactions with humans and social interactions with conspecifics on the risk of zooanthroponotic outbreaks among wildlife populations.
Pandemics caused by pathogens that originate in wildlife highlight the importance of understanding the behavioral ecology of disease outbreaks at human-wildlife interfaces. Specifically, the relative effects of human-wildlife and wildlife-wildlife interactions on disease outbreaks among wildlife populations in urban and peri-urban environments remain unclear. We used social network analysis and epidemiological Susceptible-Infected-Recovered models to simulate zooanthroponotic outbreaks, through wild animals' joint propensities to co-interact with humans, and their social grooming of conspecifics. On 10 groups of macaques (Macaca spp.) in peri-urban environments in Asia, we collected behavioral data using event sampling of human-macaque interactions within the same time and space, and focal sampling of macaques' social interactions with conspecifics and overall anthropogenic exposure. Model-predicted outbreak sizes were related to structural features of macaques' networks. For all three species, and for both anthropogenic (co-interactions) and social (grooming) contexts, outbreak sizes were positively correlated to the network centrality of first-infected macaques. Across host species and contexts, the above effects were stronger through macaques' human co-interaction networks than through their grooming networks, particularly for rhesus and bonnet macaques. Long-tailed macaques appeared to show intraspecific variation in these effects. Our findings suggest that among wildlife in anthropogenically-impacted environments, the structure of their aggregations around anthropogenic factors makes them more vulnerable to zooanthroponotic outbreaks than their social structure. The global features of these networks that influence disease outbreaks, and their underlying socio-ecological covariates, need further investigation. Animals that consistently interact with both humans and their conspecifics are important targets for disease control
Recommended from our members
Impact of joint interactions with humans and social interactions with conspecifics on the risk of zooanthroponotic outbreaks among wildlife populations
© 2022 The Author. Published by Springer Nature. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisherâs website: https://doi.org/10.1038/s41598-022-15713-6Pandemics caused by pathogens that originate in wildlife highlight the importance of understanding the behavioral ecology of disease outbreaks at human-wildlife interfaces. Specifically, the relative effects of human-wildlife and wildlife-wildlife interactions on disease outbreaks among wildlife populations in urban and peri-urban environments remain unclear. We used social network analysis and epidemiological Susceptible-Infected-Recovered models to simulate zooanthroponotic outbreaks, through wild animalsâ joint propensities to co-interact with humans, and their social grooming of conspecifics. On 10 groups of macaques (Macaca spp.) in peri-urban environments in Asia, we collected behavioral data using event sampling of human-macaque interactions within the same time and space, and focal sampling of macaquesâ social interactions with conspecifics and overall anthropogenic exposure. Model-predicted outbreak sizes were related to structural features of macaquesâ networks. For all three species, and for both anthropogenic (co-interactions) and social (grooming) contexts, outbreak sizes were positively correlated to the network centrality of first-infected macaques. Across host species and contexts, the above effects were stronger through macaquesâ human co-interaction networks than through their grooming networks, particularly for rhesus and bonnet macaques. Long-tailed macaques appeared to show more intraspecific variation in these effects. Our findings suggest that among wildlife in anthropogenically-impacted environments, the structure of their aggregations around anthropogenic factors makes them more vulnerable to zooanthroponotic outbreaks than their social structure. The global features of these networks that influence disease outbreaks, and their underlying socio-ecological covariates, need further investigation. Animals that consistently interact with both humans and their conspecifics are important targets for disease control