Pandemic A/H1N1/2009 influenza virus in Swine, Cameroon, 2010 (original) (raw)

Isolation of influenza A viruses from pigs in Ibadan, Nigeria

The authors investigated influenza virus types in pigs in Ibadan, a city in Oyo State, south-western Nigeria. From April to June 2008, nasal swabs were collected from pigs at three locations in Ibadan. Influenza A viruses (four A [H1N1], two A [H3N2] and one A [H1N1]-A [H3N2] double reactant) were isolated from 7 of the 50 apparently healthy Landrace pigs tested. This study is the first documented isolation of swine influenza viruses in Nigeria and it reveals that different strains of influenza viruses co-circulate in pigs in Ibadan. These pigs serve as reservoirs of different subtypes of influenza viruses and potential ‘mixing vessels’ in which genetic reassortment and the generation of future human pandemic strains could occur. These findings support the need for adequate and periodic surveillance among swine populations and pig handlers in Nigeria to detect circulating strains of influenza viruses. This would serve as an effective early warning system.

Footprints of swine influenza H1N1 and H3N2 in pigs from southern Kaduna, Nigeria

Sokoto Journal of Veterinary Sciences

Influenza A virus presents a significant public health burden worldwide, with the 1918 Spanish flu pandemic being the most dramatic example. Swine influenza viruses can be transmitted to humans through occupational exposures and in live pig markets. Novel variants can emerge in pigs because they can be infected by human, avian and swine strains. This study was carried out to determine the seroprevalence and serotypes of swine influenza in pigs from a major slaughter slab in southern Kaduna. Using competitive ELISA and haemagglutination-inhibition (HI) assays, 305 swine sera were analysed. The result showed an overall seroprevalence of 28.20% (n=86), with H3N2 7.87% (n=24) emerging as the most dominant subtype in circulation. Concurrent antibody detection of H1N1 in 5.26% (n=16) was also detected in boar 2.62% (n=8) and sows 2.62% (n=8). This study revealed swine Influenza H1N1 and H3N2 serotypes are in circulation in pigs in Kaduna State, and that reassortment in the instance of co-...

Molecular detection of influenza A(H1N1)pdm09 viruses with M genes from human pandemic strains among Nigerian pigs, 2013–2015: implications and associated risk factors

Epidemiology and Infection, 2017

SUMMARYIn the post-pandemic period, influenza A(H1N1)pdm09 virus has been detected in swine populations in different parts of the world. This study was conducted to determine the presence and spatial patterns of this human pandemic virus among Nigerian pigs and identify associated risk factors. Using a two-stage stratified random sampling method, nasal swab specimens were obtained from pigs in Ibadan, Nigeria during the 2013–2014 and 2014–2015 influenza seasons, and the virus was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Purified RT-PCR products were sequenced in both directions, and sequences were aligned using MUSCLE. Phylogenetic analysis was conducted in MEGA6. Purely spatial scan statistics and a spatial lag regression model were used to identify spatial clusters and associated risk factors. The virus was detected in both seasons, with an overall prevalence of 8·7%. Phylogenetic analyses revealed that the M genes were similar to those of pandemic str...

DETECTION OF INFLUENZA A VIRUS IN PIGS IN LAGOS, NIGERIA

African Journal of Clinical and Experimental Microbiology, 2012

This study detected and subtyped strains of influenza virus from pigs in Lagos, South-western Nigeria. A total of 116 (58 nasal and 58 throat) samples from healthy pigs were analysed from two different sites in Ayedoto farm at Ojo Local Government between June and September, 2010 using reverse transcription polymerase chain reaction (RT-PCR). Influenza virus type A 31(26.7%) was detected. Subtyping was done using RT-PCR with H1, H3 and H5 primers and only subtypes H1 [5(16.1%)] and H5 [5(16.1%)] were detected. No positive detection was made for subtype H3. This research work is the first documented detection of influenza A virus in pigs in Lagos, Nigeria and demonstrates the need for a sustainable surveillance mechanism of swine and other influenza viruses to be able to prevent influenza epidemic in the environment.