Coronaviruses: a review of their properties and diversity

Human coronaviruses, which hitherto were causative agents of mild respiratory diseases of man, have recently become one of the most important groups of pathogens of humans the world over. In less than two decades, three members of the group, severe acute respiratory syndrome (SARS) coronavirus (CoV), Middle East respiratory syndrome (MERS)-CoV, and SARS-COV-2, have emerged causing disease outbreaks that affected millions and claimed the lives of thousands of people. In 2017, another coronavirus, the swine acute diarrhea syndrome (SADS) coronavirus (SADS-CoV) emerged in animals killing over 24,000 piglets in China. Because of the medical and veterinary importance of coronaviruses, we carried out a review of available literature and summarized the current information on their properties and diversity. Coronaviruses are single-stranded RNA viruses with some unique characteristics such as the possession of a very large nucleic acid, high infidelity of the RNA-dependent polymerase, and high rate of mutation and recombination in the genome. They are susceptible to a number of physical agents and several chemical agents used for disinfection procedures in hospitals and laboratories. They exhibit considerable genetic and host diversity, causing diseases of gastrointestinal and respiratory system in a wide range of vertebrate hosts including humans. The high prevalence of coronaviruses in domestic and wild animals, especially bats and birds, and the propensity for their genomes to undergo mutation and recombination may lead to emergence of new coronaviruses that could pose a serious threat to human and animal health

Prevalence of hepatitis B surface antigen, hepatitis C and human immunodeficiency virus antibodies in a population of students of tertiary institution in Nigeria

Objective: Human immunodeficiency virus (HIV); hepatitis B virus; and hepatitis C viruses (HCV) are major causes of mortality and morbidity worldwide. They are also among the commonest transfusiontransmissible infectious agents. Students of higher institutions are often used as voluntary unpaid donors by many hospitals in Nigeria. In this study; the prevalence of HIV and HCV and HBsAg is determined in a population of students attending Ladoke Akintola University of Technology in south west Nigeria; to provide background information on the burden of these infections in this population. Materials and Methods: Serum samples were obtained from students of the Pre-degree Science programme of Ladoke Akintola University of Technology; Ogbomosho and tested for antibodies to HIV; HCV and HBsAg using the ELISA procedure. Results: The prevalence rates of antibodies to HIV and HCV in the student population were 0and 4.8; respectively and that of HBsAg was 9.5. Conclusion: The findings of this study which showed that the prevalence of antibodies to HIV and of HBsAg in this group of students is somewhat similar to those carried out in similar populations. This strongly suggests that the viral burden amongst this population of students is similar and that probably similar factors (demographic) are responsible for maintaining this level of viral load. Further studies would be needed to elucidate the reasons why this is the case. Also it would be necessary to reemphasize the methods of prevention of transmission of these viruses; and to ensure their implementation in order to reduce the viral levels and therefore avoid the long term sequalae

Epidemiolgy of bacterial zoonoses in Nigeria

This paper dicusses the epidemiology and epizootiology of bacterial zoonotic diseases in Nigeria. Six diseases are discussed including anthrax; brucellosis; bovine tuberculosis; campylobacteriosis leptospirosis; salmonellosis and tetanus. All axcept anthrax are enzootic and endemic in the country; and have been associated with high morbidity in human and the animal populations. The exact impact of the diseases on the general population in unknown because they are grossly underreported and underrecognized

Antigenic relatedness of selected flaviviruses: study with homologous and heterologous immune mouse ascitic fluids

A relacao antigenica de 9 Flavivirus, febre amarela (YF), Wesselsbron (WSL), Uganda S (UGS), Potiskum (POT), West Nile (WN), Banzi (BAN), Zika (ZK), Dengue tipo 1 (DEN-1) e Dengue tipo 2 (DEN-2), foi avaliada por reacao de inibicao da hemaglutinacao cruzada (cross-HI) e reacao de fixacao do complemento cruzada (Cross-CF) entre cada um dos virus e seu fluido ascitico homologo em camundongos. Medias de titulos foram calculadas usando os titulos heterologos e homologos. Reacoes cruzadas CF revelaram maiores variacoes antigenicas entre virus do que reacoes cruzadas HI. Nao houve variacao antigenica significativa entre virus WSL, POT e YF usando cada um dos metodos. Todavia, diferencas definidas da antigenicidade foram observadas entre eles e os virus UGS, BAN e ZK. Nao existiram diferencas significativas entre UGS, BANe ZK ou entre DEN-1 e DEN-2. A relacao sorologica entre Flavivirus e importante para se estabelecer o diagnostico e a epidemiologia destas infeccoes na Africa