Investigating associations between nematode infection and three measures of sociality in Asian elephants

Frequent social interactions, proximity to conspecifics, and group density are main drivers of infections and parasite transmissions. However, recent theoretical and empirical studies suggest that the health benefits of sociality and group living can outweigh the costs of infection and help social individuals fight infections or increase their infection-related tolerance level. Here, we combine the advantage of studying artificially created social work groups with different demographic compositions with free-range feeding and social behaviours in semi-captive Asian elephants (Elephas maximus), employed in timber logging in Myanmar. We examine the link between gastro-intestinal nematode load (strongyles and Strongyloides spp.), estimated by faecal egg counts, and three different aspects of an elephant's social world: individual solitary behaviour, work group size, and work group sex ratio. Controlling for sex, age, origin, time since last deworming treatment, year, human sampler bias, and individual identity, we found that infection by nematodes ranged from 0 to 2720 eggs/g between and within 26 male and 45 female elephants over the 4-year study period. However, such variation was not linked to any investigated measures of sociality in either males or females. Our findings highlight the need for finer-scale studies, establishing how sociality is limited by, mitigates, or protects against infection in different ecological contexts, to fully understand the mechanisms underlying these pathways. Significance statement Being social involves not only benefits, such as improved health, but also costs, including increased risk of parasitism and infectious disease. We studied the relationship between and three different sociality measures-solitary behaviour, group size, and the proportion of females to males within a group-and infection by gut nematodes (roundworms), using a unique study system of semi-captive working Asian elephants. Our system allows for observing how infection is linked to sociality measures across different social frameworks. We found that none of our social measures was associated with nematode infection in the studied elephants. Our results therefore suggest that here infection is not a large cost to group living, that it can be alleviated by the benefits of increased sociality, or that there are weak infection-sociality associations present which could not be captured and thus require finer-scale measures than those studied here. Overall, more studies are needed from a diverse range of systems that investigate specific aspects of social infection dynamics.Peer reviewe

Investigating associations between nematode infection and three measures of sociality in Asian elephants

Frequent social interactions, proximity to conspecifics, and group density are main drivers of infections and parasite transmissions. However, recent theoretical and empirical studies suggest that the health benefits of sociality and group living can outweigh the costs of infection and help social individuals fight infections or increase their infection-related tolerance level. Here, we combine the advantage of studying artificially created social work groups with different demographic compositions with free-range feeding and social behaviours in semi-captive Asian elephants (Elephas maximus), employed in timber logging in Myanmar. We examine the link between gastro-intestinal nematode load (strongyles and Strongyloides spp.), estimated by faecal egg counts, and three different aspects of an elephant's social world: individual solitary behaviour, work group size, and work group sex ratio. Controlling for sex, age, origin, time since last deworming treatment, year, human sampler bias, and individual identity, we found that infection by nematodes ranged from 0 to 2720 eggs/g between and within 26 male and 45 female elephants over the 4-year study period. However, such variation was not linked to any investigated measures of sociality in either males or females. Our findings highlight the need for finer-scale studies, establishing how sociality is limited by, mitigates, or protects against infection in different ecological contexts, to fully understand the mechanisms underlying these pathways.Significance statementBeing social involves not only benefits, such as improved health, but also costs, including increased risk of parasitism and infectious disease. We studied the relationship between and three different sociality measures-solitary behaviour, group size, and the proportion of females to males within a group-and infection by gut nematodes (roundworms), using a unique study system of semi-captive working Asian elephants. Our system allows for observing how infection is linked to sociality measures across different social frameworks. We found that none of our social measures was associated with nematode infection in the studied elephants. Our results therefore suggest that here infection is not a large cost to group living, that it can be alleviated by the benefits of increased sociality, or that there are weak infection-sociality associations present which could not be captured and thus require finer-scale measures than those studied here. Overall, more studies are needed from a diverse range of systems that investigate specific aspects of social infection dynamics.</p

Migration patterns & their associations with health and human rights in eastern Myanmar after political transition: results of a population-based survey using multistaged household cluster sampling

Abstract Background Myanmar transitioned to a nominally civilian government in March 2011. It is unclear how, if at all, this political change has impacted migration at the household level. Methods We present household-level in- and out-migration data gathered during the Eastern Burma Retrospective Mortality Survey (EBRMS) conducted in 2013. Household level in-and out-migration information within the previous year was gathered via a cross-sectional, retrospective, multi-stage population-based cluster randomized survey conducted in eastern Myanmar. Univariate, bivariate and regression analyses were conducted. Results We conducted a cross-sectional survey of 6620 households across Eastern Myanmar between July and September of 2013. Out-migration outstripped in-migration more than 6:1 overall during the year prior to the survey – for international migration this ratio was 29:1. Most in-migrants had moved to their present location in the study area from other areas in Myanmar (87%). Only 11.3% (27 individuals) had returned from another country (Thailand). Those who migrated out of eastern Myanmar during the previous year were more likely to be male (55.2%), and three times more likely to be between the ages of 15–25 (49.5%) than non-migrants. The primary reason cited for a return to the household was family (26.3%) followed by work (23.2%). The primary reason cited for migrating out of the household was for education (46.4%) followed by work (40.2%). Respondents from households that reported out-migration in the past year were more likely to screen positive for depressive symptoms than households with no migration (PR 1.85; 95% CI 1.16, 2.97). Women in households with in-migration were more likely to be malnourished and had a higher unmet need for contraception. Forced labor, one subset of human rights violations experienced by this population, was reported by more in-migrant (8%) than out-migrant households (2.2%), though this finding did not reach statistical significance. Conclusions These analyses suggest that opportunities for employment and education are the primary drivers of migration out of the household, despite an overall improvement in stability and decrease in prevalence of human rights violations found by EBRMS 2013. Additionally, migration into and out of households in eastern Myanmar is associated with changes in health outcomes

Health and human rights in eastern Myanmar after the political transitionWARNING a population-based assessment using multistaged household cluster sampling

© 2015 Parmar et al. Background: Myanmar transitioned to a nominally civilian parliamentary government in March 2011. Qualitative reports suggest that exposure to violence and displacement has declined while international assistance for health services has increased. An assessment of the impact of these changes on the health and human rights situation has not been published. Methods and Findings: Five community-based organizations conducted household surveys using two-stage cluster sampling in five states in eastern Myanmar from July 2013-September 2013. Data was collected from 6, 178 households on demographics, mortality, health outcomes, water and sanitation, food security and nutrition, malaria, and human rights violations (HRV). Among children aged 6-59 months screened, the prevalence of global acute malnutrition (representing moderate or severe malnutrition) was 11.3% (8.0 - 14.7). A total of 250 deaths occurred during the year prior to the survey. Infant deaths accounted for 64 of these (IMR 94.2; 95% CI 66.5-133.5) and there were 94 child deaths (U5MR 141.9; 95% CI 94.8-189.0). 10.7% of households (95% CI 7.0-14.5) experienced at least one HRV in the past year, while four percent reported 2 or more HRVs. Household exposure to one or more HRVs was associated with moderate-severe malnutrition among children (14.9 vs. 6.8%; prevalence ratio 2.2, 95% CI 1.2-4.2). Household exposure to HRVs was associated with self-reported fair or poor health status among respondents (PR 1.3; 95% CI 1.1 - 1.5). Conclusion: This large survey of health and human rights demonstrates that two years after political transition, vulnerable populations of eastern Myanmar are less likely to experience human rights violations compared to previous surveys. However, access to health services remains constrained, and risk of disease and death remains higher than the country as a whole. Efforts to address these poor health indicators should prioritize support for populations that remain outside the scope of most formal government and donor programs

Seroprevalence and associated risk factors of Toxoplasma gondii infection among slaughterhouse workers in Yangon Region, Myanmar: A cross-sectional study

Background Toxoplasmosis, having the significant consequences affecting mortality and quality of life, is still prevalent in various places throughout the world. The major gap in surveillance for Toxoplasma gondii infection among high-risk population, slaughterhouse workers, is an obstacle for the effective policies formulation to reduce the burden of toxoplasmosis in Myanmar. Therefore, this study aimed to assess the seroprevalence of toxoplasmosis and associated factors of seropositivity among slaughterhouse workers in Yangon Region, Myanmar. Methods A cross-sectional study that was conducted from June to November 2020 included 139 slaughterhouse workers involving at five main slaughterhouses under Yangon City Development Committee, Myanmar. The presence of IgG and IgM anti-T. gondii antibodies in serum was detected using the OnSite Toxo IgG/IgM Combo Rapid Test. A face-to-face interview was also performed using pretested structured questionnaires to obtain the detail histories: sociodemographic characteristics, level of knowledge, occupational factors, and environmental factors related to T. gondii infection. Bivariate logistic regression was used to determine the factors associated with T. gondii infection. Results Of all participants, the overall seroprevalence of anti-T. gondii was 43.9% (95% CI: 35.5–52.5%), of whom 98.4% (95% CI: 91.2–100.0%) were reactive only for IgG antibody and 1.6% (95% CI: 0.0–8.8%) were reactive for IgG and IgM antibodies. The significant factors associated with the seropositivity of T. gondii antibodies were blood transfusion history (OR: 5.74, 95% CI: 1.17–28.09), low level of knowledge (OR: 2.91, 95% CI: 1.46–5.83), contact with animal organs, muscles or blood (OR: 14.29, 95% CI: 1.83–111.51), and animals most frequently slaughtered (cattle) (OR: 3.22, 95% CI: 1.16–8.93). Conclusions A high seroprevalence of toxoplasmosis was detected among slaughterhouse workers in Yangon Region and it raises a significant public health concern. Therefore, providing health education regarding toxoplasmosis, enforcement of personal hygiene practices in workplaces, the establishment of training for occupational hygiene, and commencement of the risk assessment and serological screening for toxoplasmosis are crucial to curtail the prevalence of T. gondii infection among slaughterhouse workers

Myanmar version of the questionnaire.

BackgroundToxoplasmosis, having the significant consequences affecting mortality and quality of life, is still prevalent in various places throughout the world. The major gap in surveillance for Toxoplasma gondii infection among high-risk population, slaughterhouse workers, is an obstacle for the effective policies formulation to reduce the burden of toxoplasmosis in Myanmar. Therefore, this study aimed to assess the seroprevalence of toxoplasmosis and associated factors of seropositivity among slaughterhouse workers in Yangon Region, Myanmar.MethodsA cross-sectional study that was conducted from June to November 2020 included 139 slaughterhouse workers involving at five main slaughterhouses under Yangon City Development Committee, Myanmar. The presence of IgG and IgM anti-T. gondii antibodies in serum was detected using the OnSite Toxo IgG/IgM Combo Rapid Test. A face-to-face interview was also performed using pretested structured questionnaires to obtain the detail histories: sociodemographic characteristics, level of knowledge, occupational factors, and environmental factors related to T. gondii infection. Bivariate logistic regression was used to determine the factors associated with T. gondii infection.ResultsOf all participants, the overall seroprevalence of anti-T. gondii was 43.9% (95% CI: 35.5–52.5%), of whom 98.4% (95% CI: 91.2–100.0%) were reactive only for IgG antibody and 1.6% (95% CI: 0.0–8.8%) were reactive for IgG and IgM antibodies. The significant factors associated with the seropositivity of T. gondii antibodies were blood transfusion history (OR: 5.74, 95% CI: 1.17–28.09), low level of knowledge (OR: 2.91, 95% CI: 1.46–5.83), contact with animal organs, muscles or blood (OR: 14.29, 95% CI: 1.83–111.51), and animals most frequently slaughtered (cattle) (OR: 3.22, 95% CI: 1.16–8.93).ConclusionsA high seroprevalence of toxoplasmosis was detected among slaughterhouse workers in Yangon Region and it raises a significant public health concern. Therefore, providing health education regarding toxoplasmosis, enforcement of personal hygiene practices in workplaces, the establishment of training for occupational hygiene, and commencement of the risk assessment and serological screening for toxoplasmosis are crucial to curtail the prevalence of T. gondii infection among slaughterhouse workers.</div

Minimal data.

BackgroundToxoplasmosis, having the significant consequences affecting mortality and quality of life, is still prevalent in various places throughout the world. The major gap in surveillance for Toxoplasma gondii infection among high-risk population, slaughterhouse workers, is an obstacle for the effective policies formulation to reduce the burden of toxoplasmosis in Myanmar. Therefore, this study aimed to assess the seroprevalence of toxoplasmosis and associated factors of seropositivity among slaughterhouse workers in Yangon Region, Myanmar.MethodsA cross-sectional study that was conducted from June to November 2020 included 139 slaughterhouse workers involving at five main slaughterhouses under Yangon City Development Committee, Myanmar. The presence of IgG and IgM anti-T. gondii antibodies in serum was detected using the OnSite Toxo IgG/IgM Combo Rapid Test. A face-to-face interview was also performed using pretested structured questionnaires to obtain the detail histories: sociodemographic characteristics, level of knowledge, occupational factors, and environmental factors related to T. gondii infection. Bivariate logistic regression was used to determine the factors associated with T. gondii infection.ResultsOf all participants, the overall seroprevalence of anti-T. gondii was 43.9% (95% CI: 35.5–52.5%), of whom 98.4% (95% CI: 91.2–100.0%) were reactive only for IgG antibody and 1.6% (95% CI: 0.0–8.8%) were reactive for IgG and IgM antibodies. The significant factors associated with the seropositivity of T. gondii antibodies were blood transfusion history (OR: 5.74, 95% CI: 1.17–28.09), low level of knowledge (OR: 2.91, 95% CI: 1.46–5.83), contact with animal organs, muscles or blood (OR: 14.29, 95% CI: 1.83–111.51), and animals most frequently slaughtered (cattle) (OR: 3.22, 95% CI: 1.16–8.93).ConclusionsA high seroprevalence of toxoplasmosis was detected among slaughterhouse workers in Yangon Region and it raises a significant public health concern. Therefore, providing health education regarding toxoplasmosis, enforcement of personal hygiene practices in workplaces, the establishment of training for occupational hygiene, and commencement of the risk assessment and serological screening for toxoplasmosis are crucial to curtail the prevalence of T. gondii infection among slaughterhouse workers.</div

English version of the questionnaire.

BackgroundToxoplasmosis, having the significant consequences affecting mortality and quality of life, is still prevalent in various places throughout the world. The major gap in surveillance for Toxoplasma gondii infection among high-risk population, slaughterhouse workers, is an obstacle for the effective policies formulation to reduce the burden of toxoplasmosis in Myanmar. Therefore, this study aimed to assess the seroprevalence of toxoplasmosis and associated factors of seropositivity among slaughterhouse workers in Yangon Region, Myanmar.MethodsA cross-sectional study that was conducted from June to November 2020 included 139 slaughterhouse workers involving at five main slaughterhouses under Yangon City Development Committee, Myanmar. The presence of IgG and IgM anti-T. gondii antibodies in serum was detected using the OnSite Toxo IgG/IgM Combo Rapid Test. A face-to-face interview was also performed using pretested structured questionnaires to obtain the detail histories: sociodemographic characteristics, level of knowledge, occupational factors, and environmental factors related to T. gondii infection. Bivariate logistic regression was used to determine the factors associated with T. gondii infection.ResultsOf all participants, the overall seroprevalence of anti-T. gondii was 43.9% (95% CI: 35.5–52.5%), of whom 98.4% (95% CI: 91.2–100.0%) were reactive only for IgG antibody and 1.6% (95% CI: 0.0–8.8%) were reactive for IgG and IgM antibodies. The significant factors associated with the seropositivity of T. gondii antibodies were blood transfusion history (OR: 5.74, 95% CI: 1.17–28.09), low level of knowledge (OR: 2.91, 95% CI: 1.46–5.83), contact with animal organs, muscles or blood (OR: 14.29, 95% CI: 1.83–111.51), and animals most frequently slaughtered (cattle) (OR: 3.22, 95% CI: 1.16–8.93).ConclusionsA high seroprevalence of toxoplasmosis was detected among slaughterhouse workers in Yangon Region and it raises a significant public health concern. Therefore, providing health education regarding toxoplasmosis, enforcement of personal hygiene practices in workplaces, the establishment of training for occupational hygiene, and commencement of the risk assessment and serological screening for toxoplasmosis are crucial to curtail the prevalence of T. gondii infection among slaughterhouse workers.</div

Seropositivity of <i>Toxoplasma gondii</i> among slaughterhouse workers.

Seropositivity of Toxoplasma gondii among slaughterhouse workers.</p

Demographics of enumerated individuals (N = 30,323).

<p>* respondents may have selected more than one language for this question</p><p>Demographics of enumerated individuals (N = 30,323).</p