Occurrence ofTaeniaspecies in pigs in slaughterhouses in Phu Tho province, northern Vietnam

Abstract

Pigs act as the intermediate hosts of the zoonotic tapeworms Taenia solium and Taenia asiatica, as well as of the non-zoonotic Taenia hydatigena. In Vietnam, human taeniasis and cysticercosis have been reported throughout the country; however, data on porcine cysticercosis are scarce. Our study aimed to estimate the prevalence of Taenia spp. in slaughtered pigs in two districts in Phu Tho, a mountainous province in northern Vietnam from where neurocysticercosis patients commonly originate. The carcasses of 399 pigs from 51 small-scale abattoirs were checked for cysticerci, while tongue, liver, masseter muscles, diaphragm and heart were sliced and examined. Retrieved cysticerci underwent polymerase chain reaction–restriction fragment length polymorphism and sequencing for species confirmation. Blood was also collected to detect antibodies by lentil lectin-purified glycoprotein enzyme-linked immunoelectrotransfer blot (LLGP-EITB) and recombinant T24H antigen (rT24H)-EITB and circulating antigens by B158/B60 Ag-ELISA. In two pigs, T. asiatica cysticerci were found, confirming the presence of the parasite in pigs in Vietnam at a low prevalence (0.5%; 95% exact confidence interval (CI): 0–1.19%). Cysticerci of T. solium were found in none of the pigs, although one serum sample was positive for antibodies in both LLGP-EITB and rT24H-EITB. Furthermore, a high prevalence of T. hydatigena cysticercosis was observed (18.0%; 95% Wilson score CI: 14.6–22.1%). In more than half of the T. hydatigena-positive pigs, circulating antigens were detected by Ag-ELISA, confirming that this test cannot be used to diagnose T. solium cysticercosis in this region. Finally, Spirometra erinaceieuropaei was found in one pig liver. It is the first record of this zoonotic cestode species in pigs in Vietnam. Overall, the findings confirmed the complex epidemiology of Taenia spp. in pigs in Vietnam.

Human Taeniasis and Cysticercosis and Related Factors in Phu Tho Province, Northern Vietnam

“…In Vietnam, 3 Taenia spp. cause human taeniasis, T. solium , T. saginata , and T. asiatica , and a recent study has also confirmed the presence of T. asiatica in pigs in Phu Tho Province [ 28 ]. This problem should be addressed in future studies by using molecular techniques.…”

“…In conclusion, notwithstanding the improvement of hygienic standards and living conditions in Vietnam in last decades, our study has shown that T. solium transmission still occurs in communities in Phu Tho Province. The consumption of raw pork and vegetables combined with traditional pig husbandry systems, poor meat inspection procedures [ 28 , 29 ], and the common habit of using night soil on agricultural lands [ 8 ] are likely to perpetuate the transmission of tapeworm infections. Health education campaigns are needed in this area to inform the population on those infection risks.…”

Helminth infections in dogs in Phu Tho Province, northern Vietnam

“…The low prevalence of T. hydatigena (0.3%) in the sampled dogs was somewhat unexpected as in the same province Lan et al. (2011) found a prevalence of 35% in dogs, while Nguyen et al. (2020) estimated the prevalence of T. hydatigena cysticercosis in the pig intermediate host at 18%.…”

“…The finding of S. erinaceieuropaei confirms the presence of this cestode in Vietnam. This cestode has previously been found in pigs ( Nguyen et al., 2020 ) and humans ( Le et al., 2017 ) in Vietnam and is a cause of sparganosis in humans.…”

“…1 ). This province is located in the Northern Midlands region of Vietnam, around 120 km from Hanoi ( Nguyen et al., 2020 ). The dog population in the province is around 260,000 ( DAH, 2020 ).…”