Abstract-An experiment was conducted to detect antibodies against Trichinella in slaughtered pigs and to identify farm management practices and risk factors associated with trichinellosis in pigs and pig farms in Kaduna Metropolis, Nigeria. A total of 286 pigs, 186 from slaughterhouses and 100 from pig farms, were tested in this study. Serum samples collected from the slaughtered pigs were tested serologically for antibodies for Trichinella by ELISA using excretory-secretory (E/S) antigen. Out of the 186 pig serum samples collected from slaughtered pigs at the main pig abattoir in Kaduna Metropolis, 56 were from juvenile pigs (10.7%) and 130 from adult pigs (14.6%). Male pigs had a prevalence rate of 12.6%, which was slightly lower than that of the females (14.1%). An overall prevalence rate of 13.4% was observed in this study. The age and sex of the animals were not associated with the infection. Also, a survey of 100 slaughtered pigs from 100 pig farms was carried out. From the structured questionnaire administered, 90% of the pig farmers had scavenging pigs, 98% had seen rodents around and within their piggeries, 85% had no rodents control program, 70% feed their pigs with food leftovers, 4% had seen their pigs interact with stray pigs, 16% feed their pigs with dead animals, and 10% had seen snakes around their piggeries. Only 2% were aware of trichinellosis while 30% knew of pork-borne diseases. Significant association existed between all the risk factors studied in the backyard pig farms visited with trichinellosis except for factors such as rodents around and within pig pens. The result also classified the distribution of pig owners based on farm management practices into categories of extensive (55%), semi-intensive (40%), and intensive (5%) with prevalence rates of 96.4%, 70.0% and 0.0% respectively. The survey established serological evidence of trichinellosis in slaughtered pigs in Kaduna Metropolis, Nigeria.

Trichinellosis is an important food-borne zoonotic disease with public health implications and a worldwide distribution. In this study, Polymerase Chain Reaction (PCR) procedure using species specific ATP6 primers was used to detect the presence of migratory Trichinella spiralis larval mitochondrial ATP6 synthase F0 subunit (ATP6) gene, after detection of antibodies to Trichinella excretory-secretory (E/S) antigen using Enzyme-linked Immunosorbent Assay (ELISA), in blood of humans in Kaduna metropolis, Nigeria. The sera of 210 participants were tested for antibodies to Trichinella E/S antigen. Overall seroprevalence rate of 39% (82/210) was recorded using ELISA. Out of the 9 ELISA samples selected randomly, PCR detected migratory Trichinella spiralis larval ATP6 gene in 4 (44.4%) at the amplicon size of 250 base pairs using the whole blood of the participants.  The 9 samples comprised 7 seropositive and 2 seronegative. The bands at lanes 1, 2, 3 and 4 were positive for ATP6 while lanes 5,6,7,8 and 9 were negative for ATP6.  Lanes 4 and 5 were ELISA negative for anti-Trichinella antibodies. One in 5 of the 128 ELISA negative samples was positive for ATP6 representing a 25.6% prevalence rate by extrapolation.  PCR using ATP6 gene as a genetic marker is valuable for the detection of T. spiralis migratory larvae in blood samples of humans and consequently the early diagnosis of trichinellosis in humans.

The sudden outbreak of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in late 2019 has necessitated discussions on different facets of the disease. These include its transmission, pathogenesis and vaccine development. The aims of this study were to discuss the SARS-COV-2 vaccines development, mechanisms of action as well as the general acceptance of these vaccines by various countries/or people. Sequel to the outbreak, several vaccines models have been discovered with promising outcomes. Few of these vaccines have been approved for emergency use; but so far, only a small portion of the world's population has been vaccinated, which is a global problem that requires urgent intervention. Knowledge of the immune response associated with SARS-CoV-2 infection is imperative to the understanding of the mechanisms of action of these vaccines. Additional researches on some of these SARS-CoV-2 prominent vaccines have become necessary. The step-to-step development of these vaccines and their effectiveness will clear the air and increase the citizen's trust in these vaccines. Amid SARS-CoV-2 vaccine development; two DNA adenovirus vaccines were developed in the United States (Oxford-AstraZeneca and Johnson and Johnson). In addition, two other mRNA modified lipid nanoparticle vaccines were developed in Europe (Pfizer-BioNTech and Moderna). This review covered the discussion on the basic molecular mechanisms of these vaccines; with particular focus on the in vivo responses toward these vaccines recorded by the vaccinated individuals.

Trichinellosis is a cosmopolitan zoonotic disease that affects a large array of mammals, birds and reptiles caused by the eating of raw or undercooked pork containing Trichinella larvae. In this study, 200 pigs slaughtered at abattoirs and slaughter slabs within Kaduna Metropolis were  screened for antibodies to Trichinella excretory-secretory (E/S) antigen using Enzyme-linked Immunosorbent Assay (ELISA). An overall prevalence rate of 16% was established. Age of the pigs revealed an association with trichinellosis (p-value=0.001) with juvenile and adult pigs recording prevalence rates of 5% and 11% respectively. Sex of the animals showed no significant association with trichinellosis but the females had a higher prevalence of 9.5% compared to the 6.5% of the males who had a greater odds (O=1.083) compared to the females (O=0.950). The farm management practices: intensive (1%), semi-intensive (2.5%) and extensive (12.5%) recorded a significant relationship with trichinellosis (p-value=0.001). Sources of the pigs whether markets, backyard farms or inheritance was significantly associated with trichinellosis (p-value=0.00) with backyard farm having the highest prevalence of 7%. Poor rodents control program, presence of snakes around and within piggery, feeding of pigs with dead animals and leftovers, lack of knowledge of pork-borne diseases, allowing pigs to scavenge and interaction of the pigs with stray pigs were very important predisposing factors to trichinellosis in pig farms established from this research. The result of this work therefore, is ofpublic health importance because meat and meat products are considered very important sources of daily protein in-take in Kaduna Metropolis, Nigeria. Keywords: Antibodies; ELISA; Kaduna Metropolis; Nigeria; trichinella; trichinellosis; predisposing factors; farm management.