Detection Of Haemagglutination–Inhibition Antibodies Against Human H&lt;sub&gt;1&lt;/sub&gt;n&lt;sub&gt;1&lt;/sub&gt; Strains Of Influenza A Viruses In Swine In Ibadan, Nigeria

Since the first detection of human H3N2 influenza virus in Taiwanese pigs in 1970, infection of pigs with wholly human viruses has been known to occur in other parts of the world. These viruses, referred to as human-like H3N2 viruses, have been known to cause clinical and subclinical infections of swine populations. Due to the paucity and complete unavailability of information on transmission of influenza viruses from other species, especially humans, to swine in Nigeria and Ghana, respectively, this study was designed to investigate the presence and prevalence of a human strain of influenza A (H3N2) in swine populations at three locations in two cities within these two West African countries in January and February, 2014. Using stratified random technique, nasal swab specimens were collected from seventy-five (75) pigs at two locations in Ibadan, Nigeria and from fifty (50) pigs in Kumasi, Ghana. These specimens were tested directly by a sensitive Quantitative Solid Phase Antigen-detection Sandwich ELISA using anti-A/Brisbane/10/2007 haemagglutinin monoclonal antibody. Influenza virus A/Brisbane/10/2007 (H3N2) was detected among pigs at the three study locations, with an aggregate prevalence of 4.0% for the two locations in Ibadan, Nigeria and also 4.0% for Kumasi, Ghana. Transmission of influenza viruses from other species to swine portends serious sinister prospects for genetic reassortment and evolvement of novel viruses. We therefore recommend that further studies should be carried out to investigate the presence of other circulating human and avian influenza viruses in swine populations in West Africa and also determine the extent of genetic reassortment of strains circulating among these pigs. This would provide an early warning system for detection of novel influenza viruses, which could have pandemic potentials.

Section: Introductionmentioning

confidence: 99%

Antigenic Detection of Human Strain of Influenza Virus A (H3N2) in Swine Populations at Three Locations in Nigeria and Ghana during the Dry Early Months of 2014

Adeola

Olugasa

Emikpe

2015

“…In this study, the combined prevalence of 90.1% obtained for influenza viruses A/Brisbane/59/2007 (H1N1) and A/Brisbane/10/2007 (H3N2) follows this trend. When compared with some studies in which low prevalence were reported (such as Zhang et al., 1989 and Ewald et al., 1994; where 1268 and 2115 pigs were tested respectively), the high prevalence obtained in Nigeria (such as by Aiki‐Raji et al., 2004; Adeniji et al., 1993; and in this study, where 107, 386, and 91 pigs were tested respectively) and in other parts of the world (such as by Zupancic et al., 2000, where 101 pigs were tested) could have been influenced by the relatively lower numbers of pigs sampled. However, as the history of the pigs in the present study clearly showed that influenza vaccines had not been administered and any maternally derived influenza antibodies must have waned considerably in these categories of pigs, our findings indicate that human‐to‐swine transmission of influenza viruses occurs in Ibadan, Nigeria.…”

Section: Discussionmentioning

confidence: 80%

“…In another study on pigs in Ibadan, Nigeria, reported in 1990, prevalence rates of antibodies to four human strains of influenza viruses, A/Chile/1/83 (H1N1), A/Taiwan/1/86 (H1N1), A/Mississippi/1/85 (H3N2) and A/Victoria/3/75 (H3N2), were 87%, 79%, 86% and 94% respectively (Olaleye et al., 1990). Furthermore, Aiki‐Raji et al. (2004) reported a prevalence of 94.39% for antibodies to a human strain of influenza H1N1in sera of pigs in Ibadan, Nigeria.…”

Section: Discussionmentioning

confidence: 99%

Detection of Haemagglutination–Inhibiting Antibodies against Human H1 and H3 Strains of Influenza A Viruses in Pigs in Ibadan, Nigeria

Adeola

Olugasa

2010

Agricultural and commercial activities have continued to bring people and pigs into regular, close contact in Ibadan, Nigeria. This study was therefore designed to investigate the transmission of human influenza viruses to pigs in Ibadan, using serological surveillance. Serum specimens were collected from ninety-one (91/199) apparently healthy, unvaccinated Landrace pigs at three locations within Ibadan from April to June, 2008. Two strains of human influenza virus A: A/Brisbane/59/2007 (H1N1) and A/Brisbane/10/2007 (H3N2) were used in Haemagglutination-Inhibition Assay for antibody detection. Prevalence of HI antibodies to the two subtypes was 90.1%. Antibodies to influenza A/Brisbane/59/2007 (H1N1) were significantly (P < 0.05) more prevalent (80.2%) than those of influenza A/Brisbane/10/2007 (H3N2) (51.6%). Titres of HI antibodies to influenza A/Brisbane/59/2007 [mean = 3331.5] were significantly higher (P < 0.05) than those of influenza A/Brisbane/10/2007 [mean = 2212.3]. This study shows that these pigs were exposed to human strains of influenza A(H1N1) and A(H3N2) either prior to or during this study. The implications of these high prevalence and antibody titres are discussed in relation to influenza virus infection among pig handlers in Ibadan, Nigeria. We recommend that periodic investigation of circulating strains of influenza viruses in pigs and humans who handle pigs regularly in Nigeria and molecular characterization of such isolates be carried out to ensure early detection of interspecies transmission and potential future pandemic strains.

“…(,b, ) and Aiki‐Raji et al. () in Nigeria. In all these studies, significant levels of antibodies to swine influenza were detected in both pigs and humans.…”

Section: Discussionmentioning

confidence: 91%

“…It is not surprising therefore that recent investigators allude to 'no earlier research project on swine influenza virus activity in Africa' (Njabo et al, 2012) or to 'first documented report of detection of swine influenza virus antibody in humans or pig handlers' (Adeola and Adeniji, 2010). Such statements do not necessarily reflect the situation as it is, considering that serological evidence of swine influenza activity in pigs and humans was investigated in Egypt by Shalaby et al (1981) and by Olaleye et al (1989aOlaleye et al ( ,b, 1990 and Aiki-Raji et al (2004) in Nigeria. In all these studies, significant levels of antibodies to swine influenza were detected in both pigs and humans.…”

Section: Discussionmentioning

confidence: 99%

Swine Influenza in Sub‐Saharan Africa – Current Knowledge and Emerging Insights

Meseko

Olaleye

Capua³

et al. 2013

Pigs have been associated with several episodes of influenza outbreaks in the past and are considered to play a significant role in the ecology of influenza virus. The recent 2009 pandemic influenza A/H1N1 virus originated from swine and not only did it cause widespread infection in humans, but was also transmitted back to swine in Asia, Europe and America. What may be the prevailing situation in Africa, particularly in sub-Saharan Africa, with respect to the circulation of classical swine or pandemic influenza? The ecology of influenza viruses, as well as the epidemiology of human or animal influenza, is poorly understood in the region. In particular, little is known about swine influenza in Africa despite the relevance of this production in the continent and the widespread pig husbandry operations in urban and rural areas. In this review, the gap in the knowledge of classical and pandemic swine influenza is attributed to negligence of disease surveillance, as well as to the economic and public health impact that the disease may cause in sub-Saharan Africa. However, emerging serological and virological evidence of swine influenza virus in some countries in the region underscores the importance of integrated surveillance to better understand the circulation and epidemiology of swine influenza, a disease of global economic and public health importance.