SEROPREVALENCE OF TRICHINELLA SPP. IN PIGS AND KNOWLEDGE, ATTITUDE AND PRACTICES OF PIG FARMERS OF EASTERN AND MIDWESTERN REGIONS OF NEPAL

A cross-sectional study was conducted on four major pig raising districts of eastern and mid-western region of Nepal from February to May 2014 to find out the seroprevalence of Trichinella spp. A total of 184 serum samples of pigs were collected and antibodies against trichinella were detected using ID screen trichinella indirect multispecies ELISA kit. The study revealed prevalence rate of 3.8% and difference in prevalence rate according to age, sex, breed, rearing system, ecozone, region & district were statistically insignificant (P>0.05) as analysed by Chi-square test using PHStat version 2.5 and Fisher’s exact test. This study confirms that antibodies of Trichinella spp. are circulating in pigs of Nepal. Further, the knowledge, attitude and practices survey of meat borne helminthic zoonoses was conducted among 50 pig raisers and pork consumers by face to face interview using a semi-structure questionnaire. This survey concludes that although there were significant portion of the respondents aware of meat borne helminthic zoonoses but there were still a noticeable proportion of respondents who didn’t have a proper knowledge that upsurge public health risks. Moreover, present-day situation of their pig raising practices & pork consumption system possess them to a menace of public health zoonoses.


Introduction
Trichinellosis is a meat borne parasitic zoonoses caused by nematode Trichinella spp. and transmitted by eating raw or undercooked pork meat containing viable larva of the parasite. Trichinella sps.are intracellular parasites of vertebrates with an entire life cycle confined to the host. It remains a serious public threat in both developed and developing countries (Murrel and Pozio, 2000;Liu and Boireau, 2002). There are eight species and three morphologically indistinguishable additional genotypes in the genus (Murrell et al. 2000;Pozio et al., 2000). Trichinella spiralis (genotype-T1) is the best known species, with high infectivity to swine and rats, with cosmopolitan distribution because of passive introduction with domestic pigs and synanthropic rats. Most infections in humans, domestic pigs, and synanthropic rats are related to this pathogen. Trichinella spiralis is an intracellular parasite specific for mammalian skeletal muscle. The infection occurs through the consumption of raw or undercooked meat from a wide variety of wild and domestic pigs (Dupouy-Camet, 2000).
In Nepal, majority of the pig population in Nepal are raised under free ranging condition under unhygienic and improper husbandry conditions. Free ranging ''back yard'' pigs and the practice of feeding offal is a very common management practice which potentially allows the transmission of trichinellosis. The certain ethnic groups in Nepal (Rai, Limbu, Magar, Gurung, Tamang, Tharu, Dalit) are mainly consuming raw pork in their regular dishes. The practice of consuming barbecued items such as momo, sukuti, sausage, salami and bacon is popular among Nepalese pork consumers. Research Article positive. Out of 52 sera tested by western blot, only 2 revealed positive whereas 39 sera tested by endpoint ELISA revealed all negative results. However, this zoonosis has never been reported from this region Joshi et al. (2001). Further, Sporadic suspicions of trichinellosis in humans have been reported by different medical hospitals in Nepal but there is no confirmation yet. Therefore, to understand pig farmer' s knowledge, attitude and their common practices of pig raising and pork consumption system, the knowledge, attitude and practices survey of meat borne helmintic zoonoses were prerequisite for designing the prevention & control stratagies for possible zoonoses and public health impact.

Study Area and Design
A cross sectional study of four major pig producing areas of Eastern and Midwestern Nepal, viz, Sunsari, Dhankuta, Banke, Surkhet consisting of two different ecozones i.e. terai and hill was done from February to May 2014. A total of 184 serum samples were collected, consisting of 92 samples from each ecozone, similarly 46 samples from each district, of pigs raised either intensively, semi intensively in commercial pig farms or free ranging pigs raised in household way. Further, the knowledge, attitude and practices survey of meat borne helmintic zoonoses, viz, cysticercosis & trichinellosis was conducted among 50 pig raisers and pork consumers by face to face interview using a semi-structure questionnaire.

Sampling Technique
The study area was purposively selected with purposive & convenience sampling of free ranging pigs whereas purposive & convenience sampling based on age, sex, breed constituting 10 % of the herd for semi intensive and intensive population.

Serological Test
Serological test was done using Trichinella Indirect multispecies ELISA kit (Sensitivity = 90.47%, n= 42, Specificity = 100%, CI95%: 98.95 -100%, n=362), based on the use of excretory/ secretory (E/S) antigen that detects anti-Trichinella antibodies directed against T. spiralis, pseudospiralis, britovi and nativa in serum, plasma or meat juice from pigs, wild boar and horses. ELISA was done as per the guidelines provided in ID Screen Trichinella Indirect Multi-species protocol.

Statistical Analysis
Data entry, management and analysis were done using program Microsoft Office Excel 2010, Chi-square (χ 2 ) analysis using commercial software PHStat version 2.5 with significance level defined at the p<0.05 and fisher's exact tests using R statistical package.

Results and Discussion
The study reveals 7 serum samples (3.8%) to be positive whereas 7 serum samples (3.8%) were considered as doubtful, later they are assumed as positive and remaining 170 serum samples (92.4%) were negative (Fig. 1). The Fig.  2 to 7 indicate seroprevalence of trichinella in pigs according to different parameters in eastern and Midwestern region of Nepal. In hilly region, 7 serum samples (7.6%) were found positive which is similar in findings of Terai region, where 7 serum samples were positive (7.6%). In eastern region of Nepal, 6 serum samples (6.9%) were found positive whereas in contrast in Midwestern region, 8 serum samples were found positive (9.5%). Pigs of less than 6 months of age, reveals 6 serum samples (5.9%) positive whereas in pigs greater than 6 months age, 8 serum samples were positive (9.6%). 7 female pig serum samples (6.3%) were found positive, similarly in male, 7 serum samples were positive (9.45%). Of intensively raised pigs 7 serum samples (6.6%) were found positive whereas in semi intensively raised pigs 3 serum samples were positive (8.6%) and 4 serum samples (9%) were positive of free ranging pigs. In exotic breed of pigs 12 serum samples (7.6%) were found positive whereas in indigenous pigs 2 serum samples were positive (7.1%). However, The difference in prevalence rate according to age, sex, breed, rearing system, eco zone, region & district was found statically non-significant (p>0.05).
Further, the study of survey concludes, about 66% of the respondents were aware of meat borne helmintic zoonotic disease from pigs caused by consumption of undercooked pork meat whereas 34% of the respondents were unaware. Majority of the respondents (84%) think pigs as dirty animals whereas minority of the respondents (16%) thinks reverse of it. Majority of the respondents (88%) consume pork & they prefer mostly (72.2%) by frying method of cooking whereas minority (27.2%) of the respondents prefer by boiled method of cooking. Although, semi intensive & intensive pig farming is increasing day by day, farmers used to raise pigs mostly under free ranging condition (74%). Most of them (66%) dewormed their pigs whereas 34% of farmers were not aware of deworming their pigs. Farmers usually (79.2%) prefer to slaughter their pigs at butchers, where in context of Nepal meat inspection act is not regulated. Majority (62%) of pig raising farmer's don't have their latrines in house & their pigs are exposed (62%) to wild boars, rodents, dogs , cats & birds which play role in the transmission of Trichinella to their domestic pigs. The table indicates the retrospective review of trichinellosis in pigs in Nepal.
Since comprehensive and complete knowledge on the epidemiological situation of the parasite in domestic pig and wild life with in the country is unknown. Freedom from Trichinella infection with in a given area is difficult to document. However, its validity and accuracy could be challenged through increased sample sizes. Furthermore, continuous surveillance and monitoring have to be implemented before concluding that Nepal is free from infection. Using confirmatory techniques with sufficient sample size should be conducted to confirm their findings and assess the public health risk. These results therefore suggest for greater attention and more intensive surveillance need in Nepal. Enhanced surveillance will enable for additional burden estimates and understanding the impact of this parasitic disease in pig as well as in human beings