Economic and value chain analysis to support an investigation and risk mitigation efforts on Marek's disease in layers in the southern part of Thailand.

Background and Aim: Marek's disease (MD) is a common lymphoproliferative disease affecting chickens and causing economic losses in commercial poultry. The MD outbreak was noticed in the southern part of Thailand in 2019. The suspected cases were found with an abnormal number of cases of layers dying with clinical signs, for example, weakness and emaciation, with evidence of MD gross lesions. This study aimed to raise awareness of the MD outbreak through value chain analysis (VCA), identifying associated possible risk factors, and estimating the associated economic impact. Materials and Methods: Value chain analysis, including seasonal calendar, value chain diagram, and layer movement mapping of the layer industry, was conducted. High-risk stakeholders were identified on the basis of risk practices and interactions between stakeholders. A case-control study was conducted to determine risk factors associated with the MD outbreak on layer farms, and partial budget analysis was used to estimate economic losses associated with MD. Results: The value chain diagram showed the linkages between stakeholders, including estimation of the percentage of products moved from one stakeholder group to another and the negotiated price. Fourteen out of 35 layer farms were case farms. Farm size and source of birds were significantly associated with the MD outbreak. The MD outbreak caused total economic losses of 295,823 USD. Farms that slaughtered infected birds with additional revenues incurred losses of 140,930 USD, whereas farms that culled infected birds without additional revenue returned incurred losses of 1995 USD. Conclusion: The VCA provided a better understanding of the layer and egg businesses in South Thailand and guided the development of questionnaires for outbreak investigation. The potential risk factor findings suggested the need for further exploration of the source of the MD outbreak.

Goat farm management and Brucella serological test among goat keepers and livestock officers, 2011-2012, Nakhon Si Thammarat Province, southern Thailand.

Brucellosis, a zoonotic disease particularly affecting goats, emerged in Thailand in 2003, resulting in both an occupational hazard for goat keepers and livestock officers, and production losses. Farm management practices have been identified as risk factors associated with Brucella sero-positivity in many studies. Our finding in this study should be considered in order to strengthen the system of biosecurity control in farm animals as one health approach. The objectives of the study were to describe the distribution of potential risk factors by types of goat farms and to document the prevalence of human Brucella sero-positivity among goat keepers and livestock officers in Nakhon Si Thammarat, Thailand. A cross-sectional study was conducted from September to December 2012. The study population included three types of goat farms: standard, community enterprise and private goat farms that were located in Nakhon Si Thammmarat Province in southern Thailand. Information on whether the farm had any Brucella sero-positivity goats since 2011 was retrieved from the local livestock office records. Information on farming management was also traced back to 2011. Field researchers collected information from goat keepers of the selected farms using a structured questionnaire. Goat keepers on all farms pre-identified (January to June 2012) as having had at least one positive goat were considered to have been exposed. Goat keepers on a random sample of farms having all goats with negative results were considered to be unexposed. Venous blood samples were collected from goat keepers exposed and unexposed and from livestock officers and the samples were tested by IgG ELISA. Statistical analysis was done under the complex survey design in R software. Fourteen standard farms, 66 community enterprise farms and 68 private farms participated in the study; 82.4% (122/148) used public pasture and 53.4% (79/148) shared breeder goats with other farms. Farm management practices corresponding to pre-identified risk factors were more common in private farms. Large herd size (≥ 51 goats) and having dogs and/or rats on the farm were significantly associated with Brucella infection in animals (P < 0.05). Similar proportions of goat keepers in positive goat farm and livestock officers were positive for Brucella antibody (8.3% and 8.8% respectively). Several goat farming management practices in the study area may increase the risk of Brucella infection in animals. Livestock officers in the area have a high risk of being infected with Brucella. Improving goat farm biosecurity practices in needed to reduce the risk of brucellosis in this area.

Epidemiologic trends of rabies in domestic animals in southern Thailand, 1994-2008.

Rabies and associated risk factors in dogs, cats and cattle (n = 3,454) in southern Thailand during 1994-2008 were evaluated by using a mixed-effect logistic regression model. Overall prevalence was 48%. In dogs, odds of being rabid were 1.7 times higher in unvaccinated dogs than in vaccinated dogs and two times higher in dogs with bite history than in dogs with no known bite history. Similarly, aggressive dogs were more likely to be rabid than non-aggressive dogs. In cattle, aggression, pharyngeal paralysis, hyperactivity, and depression were clinical signs associated with being rabid. Annual fluctuations of the species-specific prevalence of rabies is suggestive of a positive correlation between canine and either feline (r = 0.60, P = 0.05) or bovine rabies (r = 0.78, P = 0.004). Insufficient vaccination coverage led to maintenance of rabies, which could be easily controlled by increased vaccine coverage and public education.

Outbreak of trichinellosis caused by Trichinella papuae, Thailand, 2006.

In 2006, the Thailand Ministry of Public Health studied 28 patients from a village in northern Thailand. All had myalgia, edema, fever, and gastrointestinal symptoms; most had eaten wild boar. A muscle biopsy specimen from a patient showed nonencapsulated larvae with a cytochrome oxidase I gene sequence of Trichinella papuae.

A suspected new species of Leishmania, the causative agent of visceral leishmaniasis in a Thai patient.

A suspected new species of Leishmania is described as the causative agent of the third reported case of autochthonous visceral leishmaniasis in a Thai man living in Southern Thailand. The results of PCR-restriction fragment length polymorphism and sequence analysis of the internal transcribed spacer 1 of ssrRNA and the mini-exon genes were different from those of previously reported Leishmania species. A direct agglutination test (DAT) revealed that antibody against Leishmania infection was detected in nine domestic cats. No potential vectors could be identified. A large-scale epidemiological survey of leishmaniasis should be urgently conducted since visceral leishmaniasis is considered an emerging disease of public health concern in Thailand.

Toxoplasmosis in piglets.

Seventeen-day-old piglets in a small holding farm in southern Thailand manifested signs of convulsion, fever, and death. The morbidity and mortality rate were approximately 26.09% (6/23) and 4.35% (1/23), respectively. Impression smear from lungs demonstrated tachyzoite stage of Toxoplasma gondii. Histopathological investigation revealed interstitial pneumonia. Further investigation, blood collection, educating the farmer, and prescribed affected herd with sulfa-trimethoprim were performed soon after Toxoplasma infection was demonstrated. A serological detection of T. gondii infection among affected herds using latex agglutination test was conducted on 14 serum samples. The overall seroprevalence was 71.43% (10/14). The titers were 1:64 in 3 pigs (21.43%), 1:128 in 4 (28.57%), 1:256 in 2 (14.29%), and 1:512 in 1 (7.14%). A cat in this farm showed antibody titer 1:32 while a dog was seronegative. Data derived from this case indicated two possible routes of transmission: transplacental infection and ingested food or water contaminated with oocysts shed by cat in this farm. However, rodents can not exclude as a role of toxoplasmosis transmission. Serological monitoring at slaughter houses combine with good sanitary practices, rodent and cat control in the farm are important measures to prevent toxoplasma infection and improve human health in the future.

Vaccination coverage and epidemiological parameters of the owned-dog population in Thungsong District, Thailand.

Canine rabies vaccination is delivered in Thungsong District, Thailand, as an annual campaign between March 1 and 31, and also at other times through private veterinary clinics, para-veterinarians and health-care staff residing in the villages. The current questionnaire-interview survey was conducted between June 23 and July 18, 2002 to determine: rabies-vaccination coverage amongst the owned-dog population; basic dog-population information; and community awareness about rabies. The modified expand programme on immunization cluster-survey method was used to collect information about dog demography and management characteristics. Household knowledge about rabies and sources of rabies information were assessed. Vaccinated dogs were identified from vaccine certificates or owner reports confirmed by vaccinators. Seventy percent (95%CI 62-78) of 364 eligible owned dogs were vaccinated within the 6 months prior to data collection. Of these 255 vaccinated dogs, 44, 21, 13, 17 and 5% were vaccinated through the annual vaccination campaign, veterinary clinics, para-veterinarians, other vaccinators and owners, respectively. Fifty-four percent of households owned dogs. The sex ratio in dogs was 2 males per female; the dog: human ratio was 1: 4.6 with an average of 0.9 dogs per household (1.7 dogs per dog-owning household). Most dogs roamed freely and these were less likely to be vaccinated compared to dogs being kept on premises or on a leash. Almost all households were aware of rabies and the need for dog rabies vaccination as a control method. Seventy-six percent believed that rabies only occurred in summer. There was little awareness about cat rabies amongst households. Vaccination coverage in the total dog population clearly has not yet reached the 80% target level set by Thailand's official rabies-control programme. Improved effectiveness of the owned-dog rabies-vaccination campaigns in each community is needed-perhaps by more community education about dog management or by better management of ownerless dogs.