Livestock diseases threatening smallholder farmers in Lao people's Democratic Republic

Purpose: In Lao People's Democratic Republic, uncontrolled animal trade, lack of animal containment and limited access to veterinary services are a growing-ground for virus spread. Foot-and-Mouth Disease (FMD) and several avian viruses are enzootic and threaten subsistence farmers. We assessed the (sero-)prevalence of several livestock viruses, and evaluated the knowledge, attitude, and practice of smallholder farmers towards FMD. Methods & Materials: In 2018, sera were collected from 394 domestic ruminants and screened using an ELISA that differentiates between infected and vaccinated animals. Questionnaires (n = 101) were statistically explored to identify knowledge gaps and risk factors related to FMD. In addition, oral and cloacal swabs, collected from 619 backyard poultry in 2011, 2014 and 2015, were tested by PCR for Newcastle disease (NDV), Influenza A, Coronavirus (CoV) and Chicken Anemia Virus (CAV). 206 poultry sera were screened by ELISA for the presence of anti-NDV and –Influenza A antibodies. Statistical and phylogenetic analyses revealed the viral infection patterns. Results: Although most farmers had very limited knowledge about FMD, many could correctly enumerate the symptoms and observed outbreaks recently. This was confirmed by our laboratory analysis: overall 37.1% of the animals were seropositive and 72.3% of the farms had at least one seropositive animal. Approx. 90% of the farmers reported that FMD negatively affects livestock trade and health. Moreover, we found high positivity rates of CoV and CAV RNA in cloacal and oral swabs (CoV: 38.3% and 6.2%; CAV: 16.1% and 1.7%). Younger animals were more likely to shed both, CoV and CAV, and similar virus strains co-circulated in chickens and ducks. Despite serological evidence of NDV and influenza A circulation (86.9% and 1.9%), viral RNA was detected in none of the swabs. Conclusion: A large proportion of the Lao population relies on subsistence livestock production which is, as shown here, severely compromised by the circulating viruses. To secure their livelihoods, vaccination programmes should target all susceptible hosts and achieve a high coverage throughout the country. These campaigns should be complemented by community-based sensitization to raise the awareness about prevention strategies, such as quarantine and trade restrictions

Prevalence of Hepatitis B virus infection among pregnant women attending antenatal clinics in Vientiane, Laos, 2008-2014

The Lao People's Democratic Republic (PDR) is still considered a highly endemic country for hepatitis B, mainly due to perinatal transmission of hepatitis B virus (HBV), despite efforts made since 2004 for universal immunization of newborns. The prevalence of HBV surface antigen (HBsAg) carriage in pregnant women is a relevant marker for the risk of mother-to-child HBV transmission. This study aimed to assess the changes in prevalence of HBV infection among pregnant women attending the Mahosot Prenatal Clinic (Vientiane Capital). <i>Methods</i>. A retrospective study was performed in the Mahosot Hospital Laboratory to collect and analyze all the results of HBsAg testing in pregnant women from 2008 to 2014. <i>Results</i>. Of a total of 13,238 tested women of mean age of 26 years, 720 women (5,44% [95 CI: 5.1-5.8%]) were found HBsAg positive, the annual prevalence ranging from 4.6% to 6.2%. A slight but steady and significant decrease in prevalence over the 7 years of the study could be documented. <i>Conclusion</i>. Although below the 8% hyperendemic threshold, the HBsAg prevalence observed in pregnant women in Vientiane reflects a high risk of HBV perinatal transmission and call for a widespread infant immunization with an HBV vaccine birth dose

Prevalence of Hepatitis B virus infection among pregnant women attending antenatal clinics in Vientiane, Laos, 2008-2014

The Lao People’s Democratic Republic (PDR) is still considered a highly endemic country for hepatitis B, mainly due to perinatal transmission of hepatitis B virus (HBV), despite efforts made since 2004 for universal immunization of newborns. The prevalence of HBV surface antigen (HBsAg) carriage in pregnant women is a relevant marker for the risk of mother-to-child HBV transmission. This study aimed to assess the changes in prevalence of HBV infection among pregnant women attending the Mahosot Prenatal Clinic (Vientiane Capital). Methods. A retrospective study was performed in the Mahosot Hospital Laboratory to collect and analyze all the results of HBsAg testing in pregnant women from 2008 to 2014. Results. Of a total of 13,238 tested women of mean age of 26 years, 720 women (5,44% [95 CI: 5.1–5.8%]) were found HBsAg positive, the annual prevalence ranging from 4.6% to 6.2%. A slight but steady and significant decrease in prevalence over the 7 years of the study could be documented. Conclusion. Although below the 8% hyperendemic threshold, the HBsAg prevalence observed in pregnant women in Vientiane reflects a high risk of HBV perinatal transmission and call for a widespread infant immunization with an HBV vaccine birth dose