Large-scale phylogenetic analysis reveals genetic diversity and geographic distribution of rabies virus in South-East and South Asia.

South-East Asia (SEA) and South Asia (SA) are two important geographic regions with the most severe enzootic rabies in the world. In these regions, phylogenetic analysis of rabies virus (RABV) has been conducted only at a country level; the results obtained from different countries are scattered and unequal, with a non-uniform system to name RABV genotypes. Therefore, it is difficult to undertake origin-tracking and compare inter-country RABV evolution and transmission. To avoid the confusion in understanding and to generate a panoramic picture of RABV genetic diversity, distribution, and transmission in SEA and SA, the present study conducted a systematic phylogenetic analysis by combining all sequences representing 2368 RABV strains submitted to GenBank by 14 rabies endemic SEA and SA countries. The results showed that RABVs circulating in two regions were classified into four major clades and many subclades: the Asia clade is circulating only in SEA, the Indian subcontinent, and Arctic-like clades only in SA, while the Cosmopolitan clade has been detected in both regions. The results also showed a wide range of hosts were infected by divergent RABV subclades, with dogs being the major transmission source. However, wildlife rabies was also found to be an important issue with 6 wild carnivore species identified as potential sources of spillover risk for sylvatic rabies to humans, domestic animals, and other wild animals. Current findings indicate that the two regions have separate virus clades circulating thus indicating the absence of cross-transmission between the regions. The study emphasizes the importance of phylogenetic analysis in the regions using uniform genotyping and naming systems for rabies surveillance, to coordinate actions of member countries to eliminate dog-mediated human rabies by 2030.

Low levels of Trichinella spp. antibodies detected in domestic pigs at selected slaughterhouses with farm-based exposure assessment in Bulacan, Philippines.

Trichinella spp. is considered as one of the most widespread food-borne zoonotic parasites globally. The disease it causes impacts human public health, pig production, and food safety. Unfortunately in the Philippines, there is still insufficient research on the presence of Trichinella among livestock. This study aims to update its status and records in the country, by verifying the presence of Trichinella spp. IgG antibodies from the selected province, Bulacan, and link its potential presence to known animal husbandry and farm practices. This study was conducted in purposively selected slaughterhouses. Pigs were randomly selected for each slaughterhouse. Blood samples were collected and serum samples were harvested from each pig samples (n = 555). Sera were tested using ELISA for the detection of Trichinella spp. IgG antibodies. For serologically positive pigs, farm-based exposure assessment was conducted to evaluate potential routes of infection. For this study, a total of 555 blood sera, wherein three blood sera were detected to be serologically positive (low prevalence of 0.54 %, 95 % CI = 0.11-1.57). Potential infection routes point towards outdoor housing management, pigs with unknown origin, pig farms presence with rodents, and pigs fed with waste as important risks. In summary, the present paper confirms that Trichinella spp. antibodies were detected in very low prevalence in Bulacan, Philippines and demonstrated the potential utilization of antibody detection as an efficient and complementary early screening tool in Trichinella detection among pigs without immediately sacrificing livestock for the sake of testing. These results merit calls for a wider screening, testing, and isolation of Trichinella spp. in pigs from other Philippine provinces.