Using Abattoir-Based Surveillance to Establish Foot-and-Mouth Disease Non-Structural Protein Seropositivity in Cattle and Pigs in Cambodia

TL;DR

This study used abattoir surveillance to find that foot-and-mouth disease is common in Cambodian cattle but rare in pigs, highlighting the need for better disease control.

Contribution

The study introduces abattoir-based surveillance as a novel method for monitoring FMD NSP antibody levels in cattle in Cambodia.

Findings

43.2% of cattle had FMD NSP antibodies, indicating widespread infection.

Cattle from Kampong Thom province, females, and those with moderate body condition had higher antibody risk.

Only 0.6% of pigs tested positive, suggesting limited FMD impact in this species.

Abstract

Foot-and-mouth disease (FMD) is a serious disease affecting cloven-hoofed animals that spreads easily and causes financial losses, especially for farmers in Cambodia. This study examined the presence of FMD antibodies in cattle and pigs to understand infection levels. Researchers tested 2238 animals at ten slaughterhouses in seven provinces between October 2019 and December 2020. Results showed that 43.2% of cattle had FMD Non-Structural Protein (NSP) antibodies, while only 0.6% of pigs tested positive. Because so few pigs were affected, further analysis focused only on cattle. The study found that certain factors were significantly associated with the presence of antibodies against the non-structural proteins of the FMD virus: cattle from Kampong Thom province, female cattle, and those with a moderate body condition score (BCS 3/5) had a higher risk. These findings demonstrated a potential method for surveillance of FMD NSP antibody monitoring at the abattoir, providing a surveillance tool to be used to assess the success of FMD control. The results indicated FMD is widespread in Cambodian cattle, while pigs are less affected. More research is needed to track the disease’s spread and identify specific virus types. The study highlights the need for better prevention strategies to protect livestock and farmers’ livelihoods.

Foot-and-mouth disease (FMD) is a contagious transboundary animal disease that causes economic loss and obstacles to international trade. Frequent FMD outbreaks in Cambodia negatively impact farmers’ and smallholders’ incomes. This study aimed to estimate the seroprevalence of FMD Non-Structural Protein (NSP) antibodies, which are an indicator of FMD antibodies raised during a natural infection rather than those produced following vaccination, that were detected using a commercial enzyme-linked immunosorbent assay (ELISA). Sample collection from cattle and pigs (n = 2238) was performed at ten abattoirs in seven provinces between October 2019 and December 2020. Overall seroprevalence in cattle and pigs was 43.2% (363/839; 95% CI 39.8–46.7), and 0.6% (9/1399; 95% CI 0.2–1.2), respectively. Only the cattle dataset was included in the risk factor analysis, as the prevalence of sero-reactors was too low in the pig dataset to be analyzed. Significant risk factors identified by the logistic regression model included the province of origin (p = 0.02), body condition score (BCS) (p = 0.0002) and sex (p = 0.0007). Odds ratios of the significant risk factors were 7.05 (95% CI 1.43–34.67; p = 0.02) for cattle that originated from Kampong Thom, 1.41 (95% CI 1.05–1.89; p = 0.02) for female cattle, and 3.28 (95% CI 1.06–10.12; p = 0.04) for animals with BCS of 3/5. The study revealed that the seroprevalence of FMD NSP in cattle presented at the abattoirs was high, while the FMD NSP seroprevalence in abattoir pigs was very low. Further investigation is required to map the disease distribution in Cambodia, especially the serotypes and strains causing clinical disease. These findings call for the extension of work on effective disease prevention measures.

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