Conference abstract

Detection of lyssavirus antigen and assessment of the levels of anti-rabies antibodies in unvaccinated apparently healthy and rabies-suspect dogs in Southeastern Nigeria

Pan African Medical Journal - Conference Proceedings. 2019:10(6).19 Dec 2019.
doi: 10.11604/pamj-cp.2019.10.6.807

Contact the corresponding author
Keywords: Dog market, dog scratch, rabies risk, rabies transmission
Oral presentation

Detection of lyssavirus antigen and assessment of the levels of anti-rabies antibodies in unvaccinated apparently healthy and rabies-suspect dogs in Southeastern Nigeria

Ukamaka Eze1,&, Ernest Ngoepe2, Boniface Anene1, Romanus Ezeokonkwo3, Chika Nwosuh4, Claude Sabeta2,5

1Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Nigeria, 2Agricultural Research Council-Onderstepoort Veterinary Institute, OIE Rabies Reference Laboratory, Onderstepoort, South Africa, 3Department of Veterinary Parasitology and Entomology, Faculty of Veterinary Medicine, University of Nigeria, 4National Veterinary Research Institute, Vom, Plateau State, Nigeria, 5Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa

&Corresponding author
Ukamaka Eze, Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Nigeria

Abstract

Introduction: rabies is an acute and progressive encephalitis caused by members of the genus Lyssavirus (Family Rhabdoviridae, order Mononegavirales). An estimated 59 000 human rabies deaths occur annually in Africa and Asia, and the majority of these deaths attributed to dog bites. In this study, we undertook a cross-sectional survey for the presence of lyssavirus antigen in brain tissues and anti-rabies antibodies in sera of unvaccinated, apparently healthy and rabies-suspect dogs slaughtered for consumption at local markets in South Eastern Nigeria.

Methods: samples (brain tissues and serum) from 278 dogs were tested for lyssavirus antigen and rabies antibodies, using the direct fluorescent antibody test (DFA) and a commercial enzyme-linked immunosorbent assay (ELISA), respectively. The FAVNT was performed exclusively on the samples with PB ≥ 40% to ascertain their endpoint titres.

Results: twenty three brain tissues (8.3%) were positive for lyssavirus antigen, and 2.5% (n = 25) of the serum samples had anti-rabies antibodies of 70% and above. There was a correlation between the ELISA and FAVNT results. The presence of lyssavirus antigen was correlated with low levels of rabies antibodies in the accompanying serum sample highlighting the notion of immune evasion following lyssavirus infection.

Conclusion: the low percentage of anti-rabies antibodies in the dog population studied suggests a dog population susceptible and at very high risk to rabies virus infection. These findings indicate a big challenge to national rabies programs and the subsequent elimination of this disease from the African continent considering that most of the dog populations are confined to the rural areas where parenteral dog vaccination is not routinely or adequately undertaken.