Rift valley fever virus infection among livestock handlers in Ibadan, Nigeria.

Livestock handlers are occupationally exposed to Rift Valley fever virus (RVFV) because of frequent and longer contact with mosquito vectors, animal blood and other tissues. We determined the seroprevalence of RVF virus infection among livestock handlers in Ibadan, Nigeria. Blood samples were collected from 265 workers in two major livestock markets and a livestock farm. Questionnaires were administered to obtain information on risk factors that may be associated with RVF virus transmission. The blood samples were tested using enzyme-linked immunosorbent assays (ELISA) to detect multispecies anti-RVF virus IgG/IgM and human anti-RVF virus IgM. In total, 14 (5.3%) of the 265 participants tested positive for anti-RVFV IgG. Seropositive individuals were more among livestock keepers (5.6%) than butchers (3.6%). Workers that frequently visited the livestock rearing areas of the northern part of Nigeria had a statistically significant (P = 0.004) higher rate of infection compared to those that did not. Very few (0.8%) of these workers knew about RVF virus while none had been vaccinated against the virus infection. This study indicates that RVF virus continues to circulate sub-clinically in Nigeria, thus the need to educate and vaccinate individuals who are occupationally at risk of infection.

Prevalence of previously undetected tuberculosis and underlying risk factors for transmission in a prison setting in Ibadan, south-western Nigeria.

People with congregational tendencies such as the prison inmates constitute an important target group in the global efforts towards the control of tuberculosis (TB). The prison setting in most developing countries particularly Nigeria, currently does not have routine diagnostic procedures for TB despite the existing risks that could facilitate disease transmission. We conducted a cross sectional study among the inmates in a major prison in south-western Nigeria for TB by screening their sputum samples using a simple random sampling method coupled with questionnaire interview, on the assumption of sub-clinical pulmonary TB infection. The overall TB prevalence found was 1.2% (2/164). Significant risk factors that could facilitate disease transmission in the prison included lack of BCG immunization (p = 0.017); history of contact with TB patients (p = 0.020); prolonged cough (p = 0.016) and drug abuse (p = 0.019). Our findings of 1.2% undetected pulmonary TB infection among the inmates though low; still reiterate previous observation that the prison setting constitutes a veritable environment for TB transmission and a threat to public health. Efforts are therefore needed to institute routine screening and reduce the risk factors associated with TB transmission among prison inmates in Nigeria.

Hepatitis B virus DNA in patients with HBsAg in south western Nigeria.

There are about 400 million people with chronic hepatitis B virus (HBV) infection worldwide with a potential of adverse sequelae including hepatocellular carcinoma. Recent data have shown that the level of HBV DNA in serum or plasma of an infected person probably reflects more accurately the replicative activity of the virus and therefore may serve as a better maker for management of the infection. This study was designed to determine the rate of detection of HBV DNA in blood samples of patients with HBsAg positive in Nigeria in comparison with the HBe and anti-HBe used widely as serological markers of infectivity. Plasma samples from 105 patients with HBsAg positive were tested for the presence of HBeAg and anti-HBe using a commercial enzyme-linked immunosorbent assay while plasma HBV DNA was quantified using the COBAS Amplicor HBV Monitor assay. Of the 105 HBsAg samples, 17 (16.2%) and 85 (81%) were positive for HBeAg and anti-HBe, respectively, while 8 (7.6%) were negative for both HBeAg and anti-HBe. HBV DNA was detected in 86 (81.9%) of the samples, out of which 15 (18.1%) and 67 (80.7%) were positive for HBeAg and anti-HBe, respectively. HBV DNA was detected in 78.4% of the HBeAg negative samples and in all the eight samples that were negative for both HBeAg and anti-HBe. The implication of these findings in the management of patients with HBV infection is compelling.

Hepatitis B and E viral infections among Nigerian healthcare workers.

BACKGROUND: There is dearth of information on Hepatitis E virus (HEV) infection and its co-infection with HBV among Nigerian healthcare workers (HCWs). Hence, there is the need to determine the rate of HEV infection and its association with HBV among HCWs who are at greater risk of nosocomial infections. METHODOLOGY: Sera from 88 HCWs and 44 non-HCWs healthy adults as controls were tested for the presence of antibody to HEV (anti-HEV). The HCWs were also tested for HBsAg and antibody to Hepatitis B core antigen (anti-HBc) using commercially available ELISA kits. RESULTS: The prevalence of anti-HEV obtained among the HCWs and controls were 43% and 94% respectively (p<0.005) while those of HBsAg and anti-HBc in HCWs were respective 13% and 56%. Overall among HCWs, the prevalence of HBV infection was 65.9%, higher than HEV infection (p<0.005) with only anti-HBc greater among the male participants (p<0.005) while co-infection of HBV with HEV was 27.3%. HEV infection was least among the Paediatricians (18%) and highest among the Surgeons (55%) while HBV infection was similar in all the different occupational groups of HCWs (44-59%) except among the Gynecologists and Obstetricians (80%). CONCLUSION: Infection with HEV is high among Nigerian HCWs but lower than the rate among non-HCWs. It is also co-infected with HBV especially among the different groups of the HCWs and could occur with the diverse clinico-serological patterns of HBV infection.

Challenges of caregivers and needs of children with parents in a Nigerian prison.

Background: Separation of a parent from the family as a result of incarceration has both short-term and long-term effects on the family, even after release from prison. This study is a report of factors and challenges of the family left to adapt to the changed circumstances of separation from parent(s) who are incarcerated. Methods: This was a cross sectional study carried out on 89 caregivers of children whose parents are incarcerated at the Agodi prison, Ibadan who gave informed and written consent to interview their families. Results: Most caregivers had little or no formal education (69.7%) and 67.4% are into petty trading or subsistence farming. A majority of the caregivers reported the need of schooling (85.4%), provision of food (84.3%) and medical care (71.9%) as major challenges, only 25% received any form of support to meet these needs. Twenty-nine (32.6%) respondents reported receiving financial support to provide for the child's feeding. Some caregivers 21 (23.6%), obtained loans to cope with the financial needs of the children while only 3 (3.4%) received support from family or other non-governmental organisations. Conclusion: The caregivers of children of prison inmates face significant challenges in meeting the needs of feeding, health and schooling. Support structures and policies to address these gaps are required.

Biological characterization of Nigerian chicken anaemia virus isolates.

Chicken anaemia virus (CAV) DNA was extracted from thymus, liver and bone marrow samples obtained from broiler and pullet chicken flocks in southwestern Nigeria, which presented with clinical signs and lesions suggestive of both infectious bursal disease and chicken infectious anaemia. While CAV was successfully isolated in MDCC-MSB1 cells from four of the pooled tissue samples, the remaining two samples failed to grow in cells. Monoclonal antibody (MAb) characterization using four MAbs produced against the reference Cuxhaven-1 (Cux-1) CAV isolate showed that Nigerian CAV isolates are antigenically related to each other and to the Cux-1 virus. Pathogenicity studies with the Cux-1 virus and one of the Nigerian isolates (NGR-1) revealed that NGR-1 was more pathogenic that the former. We conclude that although Nigerian CAV isolates are antigenically related to each other, they differ in terms of cell culture growth characteristics and probably pathogenicity. These findings further confirm that CAV exists and can no longer be ignored in poultry disease diagnosis in Nigeria. Cases hitherto diagnosed as IBD may actually be CIA or a co-infection of the two.

Affinity (tropism) of caprine arthritis encephalitis virus for brain cells.

One of the constraints in unraveling the mysteries blurring the advancement of research in the quest to totally put HIV problems under control is getting the appropriate animal model that would truly simulate human cases. This problem is more apparent in studies involving the central nervous system. Consequently, a viable animal model to generate information for the production of drugs and vaccines for the prevention and or control of lentiviral induced dementia in affected host animals is pertinent and vital. In this study, explant cultures prepared from the brain of new-born goat-kid were infected with CaprineArthritis Encephalitis (CAE) virus- a retrovirus affecting goats. The specific brain cell types infected by the (CAE) virus were determined using reverse-transcription polymerase chain reaction (RT-PCR) and transmission electron microscopy (TEM techniques). TEM showed that in 85 - 90% cases, microglia were the cells specifically infected by the virus. Amplification of the genomic sequence of the envelope and the gag genes by RT-PCR confirmed the presence of CAEV proviral DNA in the brain cells of affected animals. No productive infection of the astrocytes was observed. The results of this study showed a lot of similarities in the tropism of CAE virus infection of goat brain cells to that of HIV infection in humans thus suggesting the potential usefulness of the caprine model for the study of HIV neuropathology. The goat model system as a non-primate model therefore could be more adaptable as a simple animal model than primate models with their complexity of anthropological, environmental and safety problems.

Sequence and phylogenetic analysis of chicken anaemia virus obtained from backyard and commercial chickens in Nigeria.

This work reports the first molecular analysis study of chicken anaemia virus (CAV) in backyard chickens in Africa using molecular cloning and sequence analysis to characterize CAV strains obtained from commercial chickens and Nigerian backyard chickens. Partial VP1 gene sequences were determined for three CAVs from commercial chickens and for six CAV variants present in samples from a backyard chicken. Multiple alignment analysis revealed that the 6% and 4% nucleotide diversity obtained respectively for the commercial and backyard chicken strains translated to only 2% amino acid diversity for each breed. Overall, the amino acid composition of Nigerian CAVs was found to be highly conserved. Since the partial VP1 gene sequence of two backyard chicken cloned CAV strains (NGR/CI-8 and NGR/CI-9) were almost identical and evolutionarily closely related to the commercial chicken strains NGR-1, and NGR-4 and NGR-5, respectively, we concluded that CAV infections had crossed the farm boundary.

Tumour markers and hepatitis C virus infection in Nigerian patients with liver diseases.

BACKGROUND: Early diagnosis of hepatocellular carcinoma (HCC) is very important and determination of serum levels of tumour markers in patients with chronic liver diseases could be of immense contribution to their management. METHOD: Forty-two adult Nigerian subjects consisting of 14 healthy subjects (Controls) and 28 patients with primary liver mass (es) and histological diagnoses of liver cirrhosis (LC) +/- chronic active hepatitis (CAH) and hepatocellular carcinoma +/- LC were studied. Their blood samples were assayed for Hepatitis B Surface Antigen (HBsAg), antibodies to HCV (anti-HCV), alkaline phosphatase (AP), Aphafeotoprotein (AFP) and Ferritin. RESULTS: The patients had HCC (10) HCC+LC(4), LC+CAH (2) and LC (12). Serum ferritin> 700ng/ml, AP> 375IU/ml and AFP>200IU/ml were detected in 32%, 11% and 32% of the patients respectively with corresponding specificities of 100%, 86% and 100%. Elevated serum levels of AFP and ferritin were found in patients with HCC +/- LC while raised serum AP occurred in those having PHCC without LC. Only combination of either AFP or ferritin to AP gave significant increase in the diagnostic yield of HCC among the patients than the use of only AR Elevated levels of serum AFP correlated with both HBV and HCV while raised serum levels of ferritin were associated with only with HBV CONCLUSION: Although combination of the tumour markers gave a higher diagnostic yield for HCC among Nigerian patients, serum AFP > 200IU/ml seems the best tumour marker in the diagnosis of PHCC among the patients.

High rate of unrecognized dengue virus infection in parts of the rainforest region of Nigeria.

Outbreaks and sporadic dengue virus infections continue to occur in Africa. Several reports of dengue among travellers returning from some African countries to Europe and North America have raised concerns about the epidemiological situation in Africa. We investigated recent dengue infections in febrile patients during the rainy season in various urban centres in the rainforest region of Nigeria, West Africa. This cross-sectional study was conducted for 8 months in 2014 with study participants from Adeoyo Hospital Yemetu - Ibadan, Nigeria. Plasma were collected from 274 febrile patients residing in 11 Local Government Areas of Oyo State. IgM antibodies were determined using semi-quantitative sandwich ELISA. Data was analyzed using Chi - Square and Fisher's exact test with SPSS 16.0. An overall prevalence of 23.4% dengue virus infection was found among study participants. Highest monthly prevalence of 40% was in April and August. The monthly distribution pattern of dengue virus infection indicates efficient virus transmission. Routine diagnosis will enhance dengue virus surveillance and improve patient care in West Africa.

Isolation and preliminary characterization of chicken anemia virus from chickens in Nigeria.

Chicken anemia virus (CAV) was isolated for the first time from the Nigerian chicken population. The virus was recovered from necropsied birds from broiler and pullet flocks that suffered disease outbreaks tentatively diagnosed as infectious bursal disease. A sensitive polymerase chain reaction (PCR) assay detected CAV DNA in tissues of necropsied birds. Restriction endonuclease analysis performed with the 733-bp PCR product and the Cfo I enzyme indicated at least two different CAVs were circulating among the Nigerian chicken population. Four isolates were obtained from pooled liver and thymus tissues using the MDCC-MSB1 cell line. These isolates were found to be antigenically closely related to the Cuxhaven-1 (Cux-1) reference strain of CAV when reacted with four monoclonal antibodies prepared against the Cux-1 virus. One of the isolates (isolate A) induced thymus atrophy, bone marrow aplasia, and low hematocrit values when inoculated into 1-day-old specific-pathogen-free chickens. These findings not only demonstrate that CAV is present in Nigeria, but they also likely represent the first cell culture isolation of the virus in Africa.

Hepatitis B surface antigen (HbsAg) in blood and genital secretions of patients with sexually transmitted diseases in Ibadan, Nigeria.

A total of 100 patients attending the Special Treatment Clinic of the University Teaching Hospital (UCH), Ibadan between October, 1998 and April, 1999 were studied to detect Hepatitis B surface antigen (HbsAg) in the blood and genital discharges. This was with a view of establishing whether infected persons (positive by blood test) also excrete the antigen, HbsAg, in their genital secretions. Urethral swabs were collected from 63 male patients, while High Vaginal and Endocervical swabs were collected from 37 female patients. Blood samples were collected from all the patients. HbsAg was tested for by Enzyme immunoassay technique with Wellcozyme HbsAg kit. Of the 63 male patients, 10 (15.9%) had HbsAg in the urethral secretion while 22 (34.9%) had it in their blood, 70% of these male patients were within the age range 11-30 years. Of the 37 female patients, 34 (92%) had HbsAg in the Endocervical secretions, 6 (16.2%) of them had HbsAg in their blood. Eighty percent of the female patients with positive HbsAg in the genital secretions were within age range 21-40 years. This study documents that Hepatitis B virus can be transmitted sexually in this environment.

Demographic factors in HIV infected patients seen at UCH, Ibadan, Nigeria.

There is a rising rate of Human Immunodeficiency Virus (HIV) infection in Nigeria. Good knowledge of the demographic characteristics of the patients with HIV/AIDS may be of great importance in understanding its epidemiology in Nigeria and could facilitate efforts at curtailing the spread of the infection. The study was planned to determine the demographic factors in Nigerian patients with HIV infection. The study was conducted at the University College Hospital (U.C.H), Ibadan, located in the South West of Nigeria. It was a retrospective study of patients with HIV infection attending the U.C.H. from 1988 to 2002. The data collected from the clinical records of the patients with HIV infection included age, sex, marital status, number of spouses, tribe, occupation, education and their religious affiliation. A total of 460 patients aged 1-76 years with peak at 30-34 years were studied. The male/female ratio was 1.06 and the males were the older group. Traders accounted for 40% with female preponderance while the artisans (19.9%) and the military (2.9%) were mostly males. The patients were of Yoruba (70.6%), Igbo (20.0%) and Hausa (9.1%) races. Among the patients with marital status, majority (71.4%) were married while those separated and widowed accounted for 3.5% and 2.6% respectively. Also, a higher proportion of the female HIV patients were Christians whereas the majority of the males were of Islamic religion. Although, there was a low frequency of records on education, the males had better formal education. In conclusion, the study shows that HIV infection is presently an adult disease affecting the most productive segment of the Nigerian population regardless of the individual occupation, educational status, tribe and religious affiliation. Also, it shows that the infection could be associated with heterosexual intercourse.

Sero-epidemiological studies of respiratory syncytial and adenoviruses in children in Ibadan, Nigeria, 1985-1988.

Retrospective and prospective serological surveys to determine the prevalence of respiratory syncytial virus (RSV) and adenovirus (ADV) infections in children with respiratory diseases were carried out from 1985 to 1988 at the University College Hospital, Ibadan, Nigeria. 306 sera from subjects between 3 months and 12 years old were assayed by complement fixation test for antibodies to both viruses. Second samples were available from 42 of the subjects for antibody conversion testing. The rate varied with age, period of the year and virus. Overall prevalences of 23.5% and 18.3% were obtained for RSV and ADV respectively. 2.6% of the subjects had antibodies to both viruses. Among 42 paired samples tested, 61.9% and 33.3% showed positive antibody conversion to RSV and ADV respectively. Although there was evidence of active circulation of both viruses throughout the year, infection with RSV was higher from September to January, while ADV infection was significantly higher during February and March. Antibody prevalence to both viruses increased with age up to a peak of 39.1% for RSV in children 5-6 years old and 32% for ADV in children 3-4 years old. None of the subjects aged 10 years and above was positive for both viruses. Both RSV and ADV are important agents of acute respiratory infection in children in Nigeria.

Igbo-Ora virus (an alphavirus isolated in Nigeria): a serological survey for haemagglutination inhibiting antibody in humans and domestic animals.

Sera from humans and animals were tested for antibodies to Igbo-Ora virus by the haemagglutination-inhibition test. Prevalence in the human population (3.6%) was lower than that in the animal population (24.5%) in the same locality. No antibodies were detected in persons less than 20 years of age; the highest prevalence of antibodies was found in those above 40 years old. Among the animal species examined, cattle showed the highest prevalence (40%) of antibodies to Igbo-Ora virus. The potential hazard of the virus to human health is discussed.

Urban yellow fever epidemic in western Nigeria, 1987.

A large epidemic of urban yellow fever occurred in April and May 1987 in Oyo State, western Nigeria. The principal vector was Aedes aegypti, breeding in domestic water containers. The 1987 outbreak followed an epidemic of sylvatic yellow fever in eastern Nigeria the previous year, and probably resulted from introduction of the virus by viraemic travellers. The outbreak in Oyo State ended in early July, by which time 805 cases and 416 deaths had been officially notified. However, surveys of 3 villages in the epicentre, a region with over 4 million inhabitants, indicated an infection rate of approximately 20%, a clinical attack rate of 2.9% and a mortality rate of 0.6%, suggesting that the true incidence of cases and deaths far exceeded the official reports. Yellow fever virus was isolated from persons with fully developed yellow fever as well as mild febrile illness. One virus isolate was made from blood of an individual with mild illness, who had received 17D vaccine 5 d earlier; monoclonal antibody analysis showed that the isolate was a wild-type virus. Larval indices of Ae. aegypti were very high; however, low vector competence of the Ae aegypti population may have provided a constraint on spread of the epidemic. In late 1987 a third epidemic appeared in Niger State, northern Nigeria, with 644 reported cases and 149 deaths. The vector(s) involved is (are) unknown.

Cytomegalovirus infection among tuberculosis patients in a chest hospital in Nigeria.

A serological study was carried out in Ibadan, Nigeria to determine the prevalence of inapparent infection with cytomegalovirus among tuberculosis patients and its relation to the epidemiology of the virus in this environment. A total of 360 sera from 161 tuberculosis patients, 89 patients other than tuberculosis and 110 healthy voluntary blood donors were examined for antibody to cytomegalovirus by the complement fixation test. One hundred and forty-one (87.6%) of the tuberculosis patients, 45 (50.6%) patients other than tuberculosis and 60 (54.6%) healthy blood donors had a complement fixing antibody to cytomegalovirus. Although the total prevalence (68.3%) of complement fixing antibody against cytomegalovirus in all the groups is high, it is higher among the tuberculosis patients than the other groups in the same environment. This shows that tuberculosis which is still a major health problem in Nigeria may be playing a significant role in the spread of cytomegalovirus in the country.

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%). There was a higher prevalence of HI antibody in adults than children. Sex distribution of positive sera showed that 37% of males and 43% of females had WNV HI antibody. There was no significant difference in the prevalence of HI antibody in both sexes. On the 123 WNV HI positive sera tested, 104 (85%) and 78 (75%) had yellow fever and Potiskum HI antibody respectively. Monotypic WNV virus reactions were frequently found in children while polytypic reactions were frequently found in adults. A total of 200 animal sera were examined, 50 camels, 50 goats, 49 cattle and 51 sheep. The highest prevalence of HI antibody was found in camels (26%), followed by sheep (20%). Percentage of positive sera in other species were: goat (18%) and cattle (6%). Of the 35 WNV HI positive animal sera, 26 and 20% reacted with Yellow fever and Potiskum virus antigens respectively.

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. Prevalence of HI antibody to each flavivirus antigen was as follows: Yellow fever 26%, Wesselsbron 18% and Uganda S 33%. Of the 207 people, 37 (18%) had yellow fever N antibody. There was a higher prevalence of N antibody to yellow fever virus in adults than children. Twenty-one people vaccinated with 17-D yellow fever vaccine donated post-vaccination sera; 10 (48%) had no prevaccination HI antibody, 7 (33%) had HI antibody to one flavivirus and 4 (19%) to two or more flaviviruses. Ninety percent of seronegative people and all those with prevaccination flavivirus antibodies developed HI or N antibody, following vaccination. A total of 58 unvaccinated people were tested for yellow fever IgM antibody by an enzyme linked immunosorbent assay, 2 (3%) were positive; suggesting that active yellow fever transmission was in progress at the time of survey.

Rift Valley fever in Nigeria: infections in domestic animals.

Between 1986 and 1989, 2,255 sera collected from six domestic animal species in Nigeria were tested for antibodies to Rift Valley fever (RVF) virus. In addition, a longitudinal study was carried out from July 1987 to December 1988, using ten sentinel flocks on four farms at Ibadan and Ile-Ife, to determine the activity of RVF virus (RVFV). All samples were tested for haemagglutination-inhibiting antibodies and positive sera were further screened, using the plaque reduction neutralisation test. Of 2,255 samples, 259 (11.5%) had haemagglutination-inhibiting and neutralising antibodies, as follows: sheep (18.7%), goats (10.4%), cattle (10.2%), horses (9.8%) and camels (3.3%). The highest prevalence of RVFV antibody was found in the plateau area (18.4%). Animals aged three years or more had a higher prevalence of antibodies to RVFV. Longitudinal studies showed seroconversion to RVFV in ten of the 210 animals which were kept under observation (4.8%). All seroconversions occurred during the wet season. The results of this study indicate that the infection of animals with RVFV is widespread in Nigeria.