Nina Matsumoto

and 10 more

African Swine Fever Virus (ASFV) causes a deadly disease of pigs which spread through southeast Asia in 2019. We investigated one of the first outbreaks of ASFV in Lao Peoples Democratic Republic amongst smallholder villages of Thapangtong District, Savannakhet Province. In this study, two ASFV affected villages were compared to two unaffected villages. Evidence of ASFV-like clinical signs appeared in pig herds as early as May 2019, with median epidemic days on 1 and 18 June in the two villages, respectively. Using participatory epidemiology mapping techniques, we found statistically significant spatial clustering in both outbreaks (P < 0.001). Villagers reported known risk factors for ASFV transmission − such as free-ranging management systems and wild boar access − in all four villages. The villagers reported increased pig trader activity from Vietnam before the outbreaks; however, the survey did not determine a single outbreak source. The outbreak caused substantial household financial losses with an average of 9 pigs lost to the disease, and Monte Carlo analysis estimated this to be USD 215 per household. ASFV poses a significant threat to food and financial security in smallholder communities such as Thapangtong, where 40.6% of the district’s population are affected by poverty. This study shows ASFV management in the region will require increased local government resources, knowledge of informal trader activity and wild boar monitoring alongside education and support to address intra-village risk factors such as free-ranging, incorrect waste disposal and swill feeding.

Nina Matsumoto

and 10 more

African Swine Fever Virus (ASFV) causes a deadly disease of pigs which spread through southeast Asia in 2019. We investigated one of the first outbreaks of ASFV in Lao Peoples Democratic Republic amongst smallholder villages of Thapangtong District, Savannakhet Province. In this study, two ASFV affected villages were compared to two unaffected villages. Evidence of ASFV-like clinical signs appeared in pig herds as early as May 2019, with median epidemic days on 1 and 18 June in the two villages, respectively. Using participatory epidemiology mapping techniques, we found statistically significant spatial clustering in both outbreaks (P < 0.001). Villagers reported known risk factors for ASFV transmission  such as free-ranging management systems and wild boar access  in all four villages. The villagers reported increased pig trader activity from Vietnam before the outbreaks; however, the survey did not determine a single outbreak source. The outbreak caused substantial household financial losses with an average of 9 pigs lost to the disease, and Monte Carlo analysis estimated this to be USD 215 per household. ASFV poses a significant threat to food and financial security in smallholder communities such as Thapangtong, where 40.6% of the district’s population are affected by poverty. This study shows ASFV management in the region will require increased local government resources, knowledge of informal trader activity and wild boar monitoring alongside education and support to address intra-village risk factors such as free-ranging, correct waste disposal and swill feeding.

Kelly Buckle

and 22 more

Foot-and-mouth disease virus (FMDV) is widespread throughout much of the world, including parts of South East Asia. As part of the World Organisation for Animal Health (OIE)’s South East Asia and China Foot‐and‐Mouth Disease Project (SEACFMD), field sampling was performed to help understand evidence of widespread virus exposure observed previously. Serum and dry mucosal swabs were collected to evaluate the presence of FMDV RNA on the nasal, oral, and dorsal nasopharyngeal mucosal surfaces of 262 healthy cattle (n=38 in Laos; n=47 in Myanmar) and buffalo (n=12 in Laos; n=2 in Myanmar) immediately following slaughter in three slaughterhouses. Swabs and serum were tested by the OIE FMD world reference laboratory using pan‐serotypic real‐time reverse transcription‐PCR (RT‐PCR) and serum was evaluated using the FMD PrioCHECK non-structural protein (NSP) ELISA. In total, 7.3% of animals had detectable FMDV RNA in one or more of the three sites including 5.3% of nasopharyngeal swabs, 2.3% of oral swabs, and 1.5% of nasal swabs. In all animals, serum was found not to contain detectable FMDV RNA, and 37.8% of animals were positive for NSP antibodies, indicating likely past exposure to FMDV. Results were comparable for Laos and Myanmar, and were similar for both cattle and buffalo. The current study demonstrates the utility of detection by swabbing the nasopharynx in the post-mortem context, in situations such as post-mortem where probang samples are not feasible. Additionally, FMDV present on the oral and nasal mucosa of clinically-healthy large ruminants in Laos and Myanmar, if viable, may potentially play a role in the epidemiology of FMD in these countries, and perhaps more widely within Southeast Asia.