Prevalence Of Rabies Antigen in The Saliva and Brains of Apparently Healthy Dogs Slaughtered for Human Consumption in Abia State, Nigeria

Abstract

The study was carried out in four Local Government Areas: Umuahia North, Isiala Ngwa North, Osisioma, Ekwauno of Abia State, to detect the presence of rabies antigen in the saliva and brain tissues of apparently healthy dogs slaughtered for human consumption.

Two rapid diagnostic tests, Rapid immunochromatographic test (RICT) and Direct Rapid Immunohistochemistry Test (dRIT) and the gold standard test, Fluorescent Antibody Test (FAT) were used to detect the presence of rabies antigen in the saliva and brains of slaughtered dogs.

A structured questionnaire was designed and administered to dog meat butchers and consumers in the selected areas to access their level of awareness of rabies infection and demonstration of exposure potentials.

A total of 100 saliva samples were obtained from 64 females and 36 male dogs from the selected areas before slaughter. One hundred brain samples were also obtained  from the  dogs after they had been slaughtered.

The saliva samples were subjected to RICT while the brain tissues were subjected to FAT and dRIT respectively. A total of 100 questionnaire were administered to respondents comprising of 81 dog consumers and 19 processors.

Five (5%) of the saliva and brain tissues samples were each positive for all the tests. All the positive cases were detected in the female dogs.

Introduction

1.1 Background of Study

Rabies is an acute, contagious and highly fatal disease of all warm blooded animals caused by rabies virus (Bourhy et al., 1993; Ogunkoya et al., 2003). The disease affects all warm-blooded animals including man (Radostits et al., 1995).

Rabies infection has a case fatality rate of almost 100 %, accounting for about 55,000 human deaths annually with most cases occurring in developing countries of Asia and Africa (WHO, 2011).

Rabies was first documented in Nigeria in humans in 1912 and in dogs in 1925 ( Boulger and Hardy,1960) and since then many authors have established that the disease is endemic in the country with more reports (WHO, 2006; 2010;Mshelbwala et al., 2013a; Hambolu et al., 2014) showing that the prevalence of the disease is on the increase.

The disease is caused by a virus of the family Rhabdoviridae and genus Lyssavirus , now called Lyssa Virus 1( RABV gen1).

It manifests in three classical stages, namely prodromal, excitatory stage and paralytic or silent stage (Idachaba et al., 2009).

The saliva of rabid dog has been documented to contain high concentration of rabies virus and serve as a medium for transmission of the infection (Bishop et al., 2002; CDC, 2007; WHO, 2008) but the virus may also be found in the tears, urine, serum and other body fluids of infected animals (Wolfgan,1999).

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