Occult Hepatitis B Virus Infection in Nigerian Blood Donors and Hepatitis B Virus Transmission Risks.

Background: Occult hepatitis B virus infection (OBI) characterized by the absence of detectable HBsAg remains a potential threat in blood safety. We investigated the actual prevalence, viral factors and genotype of OBI infections in Nigerian blood donors.

Methods: Serum collected from two blood banks were reconfirmed as HBsAg seronegative by ELISA.

Immunity to poliovirus serotypes in children population of selected communities in South-west, Nigeria.

Background: Poliovirus outbreaks are still reported in Nigeria despite renewed efforts to improve vaccine coverage, thus suggesting the existence of susceptible hosts. Also, there is anecdotal evidence of variation in vaccine coverage by region and specifically between urban and rural communities. Consequently, this study assessed neutralizing antibodies to poliovirus serotypes among children in selected urban and rural communities in south western Nigeria.

Seroprevalence of parvovirus B19 IgG and IgM antibodies among pregnant women in Oyo State, Nigeria.

Introduction: Human parvovirus B19 causes a wide range of complications in pregnant women including abortion, severe fetal anemia, non-immune hydrops fetalis, and even intrauterine fetal death. However, there is a dearth of information on the prevalence of the virus among pregnant women in southwestern Nigeria.

Methodology: Blood samples were collected from 231 pregnant women and screened for antibodies to human parvovirus B19 IgM and IgG using an enzyme immunosorbent assay kits.

Absence of HIV-1 and HIV-2 seroconversions in a cohort medical students in a Nigerian medical school.

A cohort of 70, HIV-1 and HIV-2 seronegative medical students were followed up for 30 months, after which 65 were retested for HIV antibody. None of the students was infected by HIV during the period of study. A questionnaire survey carried out showed that all the students had a very good knowledge of HIV, its mode of transmission, control and prevention.

Rabies and antirabies immunization in South Western Nigeria: knowledge, attitude and practice.

Factors responsible for the continued endemicity of rabies in Nigeria were determined by carrying out a knowledge, attitude and practice study among residents of Osun State. Structured questionnaires were administered to 679 individuals comprising students, traders and civil servants. Only 33.

HIV type 1 strains from East and West Africa are intermixed in Sudan.

The genetic subtypes of HIV-1 in the Sudan epidemic have not been characterized. Here we report the partial sequencing and analysis of 30 strains collected from HIV-1-positive patients and blood donors in Khartoum in 1998 and 1999. From analysis of partial pol and env sequences, it was determined that 50% were subtype D and 30% were subtype C.

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

The antigenic relationship of 9 flaviviruses, Yellow fever (YF), Wesselsbron (WSL), Uganda S (UGS), Potiskum (POT), West Nile (WN), Banzi (BAN), Zika (ZK), Dengue type 1 (DEN-1) and Dengue type 2 (DEN-2), was assessed by cross-haemagglutination-inhibition (Cross-HI) and cross-complement fixation (Cross-CF) reactions between each of the viruses and their homologous immune mouse ascitic fluids. Titre ratios were calculated using the heterologous and homologous titres. Cross-CF reactions revealed wider antigenic variations among viruses than Cross-HI reactions.

Preliminary studies on the use of solid-phase immunosorbent techniques for the rapid detection of Wesselsbron virus (WSLV) IgM by haemagglutination-inhibition.

Serum samples from 446 randomly selected persons belonging to different age groups and locations in Nigeria were tested for the presence of WSLV IgM using the flavivirus haemagglutination-inhibition (HI) test adopted to the solid-phase immunosorbent technique (SPIT). 61 (14%) persons had IgM to WSLV only, while 9 (2%) persons had heterologous IgM to WSLV and two other flaviviruses, namely yellow fever and Uganda S viruses. There was a high prevalence of IgM in people of younger age groups than those in older groups.

Acute bronchiolitis in tropical Africa: a hospital-based perspective in Ibadan, Nigeria.

In a 30-month prospective study of severe acute lower respiratory infections in hospitalized pre-school Nigerian children, acute bronchiolitis was diagnosed in 67 cases; 19 (28.4%) and 2 (3.0%) of these had concomitant pneumonia or croup, respectively.

Respiratory syncytial virus--associated lower respiratory diseases in hospitalised pre-school children in Ibadan.

An analysis of the features of lower respiratory diseases (LRD) associated with Respiratory Syncytial Virus (RSV) in 21 children aged 1-23 months, indicated that the clinical features did not differ appreciably from those described for LRD due to other infective agents. It was however, remarkable that none of the children was grossly malnourished, neither was there any death. The final respiratory diagnoses were bronchiolitis alone (6 cases), bronchopneumonia (6 cases), empyema/pleural effusion (3 cases, including one with bronchopneumonia), lobar pneumonia (3 cases, including one with associated bronchopneumonia).

Dengue type 1 epidemic with haemorrhagic manifestations in Fiji, 1989-90.

A dengue type 1 epidemic occurred in Fiji between July 1989 and July 1990. Virus isolation in C6/36 cell cultures and Toxorhynchites mosquitos yielded 36 strains. Of the 3686 cases recorded by the Ministry of Health, 60% involved indigenous Fijians and 37%, Indians.

Haemagglutination-inhibiting antibodies against influenza A and B in human sera collected from five ecological zones in Nigeria.

The prevalence of antibodies to the haemagglutinins of two influenza A subtype, H1N1 and H3N2 and influenza B in sera collected from 1986 to 1988 from persons of different ages and from 10 locations in 5 ecological zones of Nigeria was determined. The levels of influenza antibodies in the sera varies with age and ecological zones of the country. A total of 1,022 sera were tested, of which 732 (71.

A survey for haemagglutination-inhibiting antibody to West Nile virus in human and animal sera in Nigeria.

A survey for West Nile Virus (WNV) haemagglutination-inhibition (HI) antibody was carried out in humans and domestic animals. Human sera were collected from Ibadan, while the animal sera were collected from both Ibadan and Maiduguri. Out of 304 human sera tested, 123 were positive (40%).

Yellow fever haemagglutination-inhibiting, neutralising and IgM antibodies in vaccinated and unvaccinated residents of Ibadan, Nigeria.

A survey for yellow fever virus haemagglutination inhibiting (HI) and neutralising (N) and IgM antibodies was carried out in unvaccinated people in Ibadan and in those immunised with the yellow fever 17-D vaccine. A total of 207 people were tested for HI antibody to yellow fever and two other flaviviruses namely: Wesselsbron and Uganda S. viruses.

Haemagglutination-inhibiting (HI) antibodies against strains of influenza A virus in horse and pig sera in Nigeria.

Sera from horses and pigs obtained from Lagos and Ibadan respectively were examined for haemagglutination-inhibiting (HI) antibodies to two strains each of H3N2 and H1N1 subtypes of influenza A virus. More horse sera had HI antibodies to the H3N2 than the H1N1 strains while pig sera reacted almost equally with strains of both subtypes. All the horse sera had HI antibodies to the two strains of H3N2 subtype (A/Mississippi/1/85 and A/Leningrad/360/86), while 87% and 14% of the horses examined were positive to A/Taiwan/1/86 and A/Chile/1/83.

West Nile Complement Fixing antibodies in Nigerian domestic animals and humans.

A survey for West Nile Complement Fixing (CF) antibody was carried out in humans and domestic animals in Nigeria. Human sera were obtained from two communities namely Ibadan and Ogbomoso but animal sera were collected from Ibadan and Maiduguri. The overall CF antibody to West Nile virus in the two localities surveyed was 65%.

Serological evidence for influenza virus activity in Nigeria (1985-1987).

A study to determine the activity of influenza virus among the children population was undertaken between 1985 and 1987 in Nigeria. Paired sera were obtained from children presenting with respiratory diseases at the children emergency and outpatient clinics of the University College Hospital, Ibadan. Forty-two paired sera were examined by haemagglutination-inhibition test to determine HI antibody level of the patients to different serotypes of influenza virus.

Wesselsbron virus infection in West African dwarf goats (Fouta djallon): virological and immunological studies.

West African dwarf goats were experimentally infected with Nigerian strain of Wesselsbron virus. Viraemia was detected in infected goats 2 days after infection and lasted for one day. A 100% mortality was observed among the infected animals; the virus was reisolated in mice from almost every tissue obtained from the bodies of infected goats.

Susceptibility of laboratory and domestic animals to experimental infection with Potiskum virus.

The biological characteristics of Potiskum virus, a hitherto undescribed virus isolated in Nigeria from the liver of a giant rat (Cricetomys gambianus), were studied by experimental infections of laboratory and domestic animals. The laboratory animal hosts used included mice, rats, rabbits and chicks. Suckling and weaning mice succumbed to fatal infection when infected with Potiskum virus by intracerebral or intraperitoneal routes.

Complement fixing antibodies against arboviruses in horses at Lagos, Nigeria.

Sixty-two sera horse collected from two stables at Lagos, Nigeria, were tested for complement fixing antibody to 8 arbovirus antigens; Chikungunya, Igbo-Ora, Yellow fever, Wesselsbron, West Nile, Potiskum, Uganda S and Rift Valley fever. Ten per cent of the horse sera examined contained CF antibody to one or more of the test antigens and indicated considerable arbovirus activity in the two stables. Reactions with flavivirus antigens were most common and the highest antibody titres were obtained with Wesselsbron and Yellow fever viruses.

An epidemiological study of rotavirus diarrhoea in a cohort of Nigerian infants: II. Incidence of diarrhoea in the first two years of life.

In a community-based prospective study of diarrhoeal diseases carried out in Ibadan, 131 infants were selected at birth. The maximum possible length of follow-up ranged from 16 to 24 months. Weekly surveillance for diarrhoea was carried out at home by Primary Health Care workers.