Authors

Discussion

Ascaris lumbricoides and Ascaris suum are two of the most widespread intestinal helminths affecting the health of humans and pigs respectively worldwide. The two species of Ascaris are morphologically indistinguishable when diagnosed through microscopy, but artificial infection studies and molecular epidemiological investigations from other countries indicate that A. lumbricoides can infect pigs and vice versa. To date, there is a dearth of similar studies that have been published in the Philippines. Hence, this study aimed to investigate the molecular identities of Ascaris spp. from humans and animals, i.e. dogs, cats, pigs, and water buffalo collected from the Philippines.

Stool samples from humans and animals were collected from eight municipalities in Caraga region in a household-based survey. The samples were processed using Kato-Katz technique for the human samples and sedimentation and flotation techniques for the animal samples and were examined through microscopy for the presence of Ascaris spp. ova. Samples were then subjected to PCR-linked RFLP (Restriction Fragment Length Polymorphism) analysis of the nuclear ITS1 region which distinguishes A. lumbricoides and A. suum upon distinctive RFLP profiles. While most of the samples exhibit the characteristic pattern of Ascaris species expected for the host, the occurrence of A. suum genotype in 19 (2.6 %)  human-derived samples and 3 (2.3 %) A. lumbricoides genotype in  pig- derived samples and of 43 (5.0 %) samples with both A.lumbricoides/A.suum patterns indicate possible cross transmission and hybridization events. Furthermore, the detection of Ascaris spp. in other animals suggests that these animals may also contribute to environmental contamination and transmission of Ascaris spp. to humas. The zoonotic potential of Ascaris should not be overlooked and must be considered in planning for more efficient control and treatment programs.