MOLECULAR DETECTION OF SWINE INFLUENZA VIRUS IN PIGS AND PIG HANDLERS IN SOME COMMUNITIES IN LAGOS STATE, SOUTH WESTERN, NIGERIA

Background/Aim: Worldwide, three Influenza A virus subtypes (H1N1, H1N2 and H3N2) in swine are major public health concerns as a result of their involvement in influenza pandemics. The aim of this study is to detect and subtype strains of influenza virus from pigs and pig handlers in Lagos, Nigeria.

Materials and Methods: A total of 150 nasal and throat swab samples were collected from pigs and pig handlers which included 87 (38 nasal and 49 throat) samples from healthy pigs and 63 (9 nasal and 54 throat) from pig handlers. The samples were collected from three different farms in three different Local Government Areas (LGAs) in Lagos State between July, 2013 and September, 2013 and screened using reverse transcriptase polymerase chain reaction (RT-PCR).

Results: Results obtained show that Influenza virus A was detected in 16 pigs (18.4%) and 2 (3.2%) from pig handlers. The positive samples were further subtyped using H1 and H3 primers and the results obtained revealed that out of the 16 positive samples from pigs, 4 (25.1%) were positive for H1 while 1 (6.3%) was positive for H3. In humans, out of the 2 positive samples, 1 (50.0%) H3 was detected. The number of positive samples from nasal and throat samples were compared and it was observed that more influenza A viruses were detected in throat samples of both humans and pigs with 2 (3.2%) and 10(11.5%) respectively while only 6 (6.9%) nasal samples in pigs alone were positive. However, there was no statistically significant difference (P = 0.36) in the use of both samples in detecting swine influenza virus in pigs and pig handlers.

Conclusion: Detection of an H3-like Infuenza A Virus in the swine population demonstrates a potential threat to human health.