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.

Haematological Changes Associated with Hepatitis B Virus Infection in Individuals with and without Sickle Cell Disease

BACKGROUND

Hepatitis B virus infection, a major public health problem that primarily affects the liver, may cause reduction in the levels of haemoglobin, haematocrit and in the extreme, could cause aplastic anaemia. The haematological characteristics could be detected with a complete blood count which could provide invaluable information for diagnosis and management of the disease.

AIM

To determine the effect of HBV infection on the blood count of individuals with sickle cell disease (SCD) and apparently normal healthy (Non-SCD).

SETTING

Non-SCD participants were recruited from the community while SCD patients in steady state were recruited from SCD routine clinics.

METHODS

The study was a cross - sectional study carried out on 1017 non-SCD and 1017 SCD individuals. Haematology Autoanalyzer was used to determine the complete blood count. Granulocyte-to-lymphocyte ratio (GLR), platelet to white blood cell count ratio (PWR) and platelet-to-lymphocyte ratio (PLR) were calculated. ELISA for HBsAg and HBV core antigen IgM antibodies were used to identify participants with HBV.

RESULTS

The non- SCD individuals infected with HBV had significantly higher WBC (7.51 ± 5.8 X109/L)) compared to a WBC (6.1 ± 3.4 X109/L) in uninfected individuals (p =0.001). PWR for HBV negative (49.9±28.6) was higher than that for HBV positive participants (41.4±17.6) (p=0.034). Mean platelet volume (MPV) of 9.93 ± 1.1fl in SCD individuals with HBV was significantly higher than 8.30 ± 0.95fl in SCD individuals without HBV (p=.001).

CONCLUSIONS

PWR and MPV may be useful as surrogate marker for detection of HBV disease progression in apparently normal healthy non - SCD and SCD populations to institute prompt appropriate ancillary investigation and treatment.

Virological investigation of fatal rabies in a minor bitten by a mongrel in Nigeria

Rabies is a deadly viral disease transmitted through bites of infected animals. Outbreaks continue to escalate in Africa, with fatalities in humans, especially in rural areas, but are rarely reported. About 40% casualties occur among children of < 15 years. A 5-year-old boy on referral from a Primary Health Care Centre to a tertiary hospital presented with anxiety, confusion, agitation, hydrophobia, photo-phobia and aero-phobia, seven weeks after he was bitten by a stray dog in a rural community in Nigeria. The patient did not receive post-exposure prophylaxis and died 48 hours post admission. Confirmatory diagnosis was rabies and the phylogenetic analysis of the partial N-gene sequence of the virus localized it to Africa 2 (genotype 1) Lyssaviruses. There was 95.7-100% and 94.9-99.5% identity between the isolate and other genotype 1 Lyssaviruses and 100% homology with rabies viruses from Mali, Burkina Faso, Senegal and Central African Republic.

Molecular characterization of canine parvovirus from domestic dogs in Nigeria: Introduction and spread of a CPV-2c mutant and replacement of older CPV-2a by the "new CPV-2a" strain

Canine parvovirus (CPV) is a contagious and highly pathogenic virus of dogs. After its first report in 1978, the CPV original type (CPV-2) was rapidly and totally replaced by three antigenic variants named CPV-2a, CPV-2b and CPV-2c that circulate in various countries at different frequencies and recently reported in Nigeria. This study describes the molecular characterization of 28 CPV strains in dogs presenting with gastroenteritis in veterinary clinics at Lagos and Ibadan, Nigeria. The results show the predominance (92.8%) of CPV-2a, while CPV-2c was found only in two samples. Phylogenetic analyses revealed that the CPV Nigerian strains were closely related to Asian strains and 26 CPV-2a out of 28 CPV sequences fell into 2 different subclades consistent with predicted amino acid mutations at position 267, 321, 324 and 440. Lys321Asn was evident in all the Nigerian strains whilst Phe267Tyr and Tyr324Ile were observed in 96.4% of the sequences, respectively. Thr440Ala occurred in 89.3% of sequences from this study. The new CPV-2a was predominant and appears to have replaced other CPV-2a strains in South-western Nigeria whilst the CPV-2c strain which is identical to the isolate recently reported in Northern Nigeria, may have been introduced in this country at the time of this study. Monitoring virus epidemiology is important to better understand the dynamics of CPV evolution and the eventual need to change or improve existing vaccination strategies.

Complete genome sequencing of H1N1pdm09 swine influenza isolates from Nigeria reveals likely reverse zoonotic transmission at the human-animal interface in intensive piggery

Prevailing agro-ecological conditions and intermingling of human and animals in intensive farms in urban and peri-urban areas in Africa favour cross species transmission of pathogens at the human-animal interface. However, molecular epidemiology studies of zoonotic swine influenza viruses in this region are limited. In this study, isolates of pandemic influenza virus (H1N1pdm09) obtained from pigs in Nigeria were fully sequenced. BLAST of swine influenza virus genes from Nigeria was carried out in GenBank and gene alignment was done using MEGA version 7. Maximum likelihood method (PhyML program) was used to determine gene evolutionary relationships with other viruses and phylogenetic trees were constructed to infer genomic clusters and relationship. Swine influenza viruses isolated and sequenced in this study were monophyletic and 99% congenetic with human isolates from Nigeria, Cameroon, Ghana and USA suggesting reverse zoonotic transmission from humans to pigs in intensive husbandry. A Q240R and S31N substitution among others were detected in the haemagglutinin and matrix genes, respectively, indicating potentials for mutations during interspecies co-mingling and transmission. The A/H1N1pdm09 viruses circulating in pigs that are also exposed to avian influenza in the same epidemiological zones could engender emergence of novel viruses with zoonotic or pandemic potential requiring enhanced surveillance and monitoring.

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.

High rate of Hepatitis B virus infection among hairdressers in Ibadan, Nigeria

Hepatitis B virus (HBV) infection is a major public health problem for over two billion people infected globally. Occupationally exposed persons are at high risk of HBV infection and, apart from medical personnel, there is dearth of information concerning the prevalence and awareness of HBV among this population in Nigeria. This study was designed to determine the levels of HBV awareness and prevalence of HBV infection among hairdressers in Ibadan, Nigeria. Hairdressers and teachers (unmatched controls) in four local government areas in Ibadan were tested for HBV infection using ELISA technique. Dried blood spot (DBS) samples were collected from 171 participants. DBS elutes from the samples were tested for HBV surface antigen (HBsAg). The rate of HBV infection was higher (p = 0.005) among the hairdressers (13.0%) than teachers (4.8%). However, teachers were better informed about HBV (38%) compared to hairdressers (13%; p = 0.0001). Differences in HBV awareness and occupation type were found to be significant (P = 0.001). Hairdressers are at high risk of HBV infection and may constitute a major source of HBV spread among urban dwellers, especially in areas where awareness is low. Routine HBV screening and appropriate interventions for hairdressers are recommended to interrupt HBV transmission.

Tissue culture isolation of lyssa viruses from apparently healthy unvaccinated dogs in Nigeria

BACKGROUND

There have been previous reports of inapparent infection and intermittent secretion of rabies virus in the saliva of apparently healthy dogs in some African countries, including Nigeria.

OBJECTIVE

The study was therefore aimed at examining the carrier status of rabies in apparently healthy Nigerian dogs in the settlement areas studied.

METHODS

Ninety-two swabs samples from oral mucosae of domestic dogs (mongrels) without vaccination history were assayed for lyssaviruses by tissue culture isolation test in Vero cells.

RESULTS

Rabies or rabies-related viruses were recovered from eighteen, representing 19.6% of the samples. The study showed that lyssaviruses were present in 4 out of the 6 settlements of the study areas. Among the areas where the viruses were present, the rate of isolation ranged from 11.1% to 66.7%. Female dogs had a little higher infection rate (12.0%) than their male counterparts (7.6%). Among age groups, the highest rate of infection (66.7%) was detected in dogs aged one to 3 years while the rate of 3.7% was found in dogs aged less than one year.

CONCLUSION

The results of this study agree with the carrier state of rabies in domestic dogs, the common reservoir hosts of its etiologic agents in Nigeria and the rest of Africa andAsia; this is a serious threat to humans in these settlements. Although the load of infective virus in saliva is lower than that in brain, saliva collection for rabies diagnosis is simple, safer, faster and cheaper. Thus we suggest that saliva samples could be used as an alternative to brain specimens for rabies virus antigen testing in dogs, especially, when it is not practicable to obtain brain specimen.

Detection and isolation of 2009 pandemic influenza A/H1N1 virus in commercial piggery, Lagos Nigeria

WHO declared pandemic of A/H1N1 influenza in 2009 following global spread of the newly emerged strain of the virus from swine. Presently there is a dearth of data on the ecology of pandemic influenza H1N1 required for planning of intervention measures in sub Saharan Africa. Herein we report isolation of 2009 pandemic influenza A/H1N1 in an intensive mega piggery farms operation in South West Nigeria. Sentinel surveillance was carried out in a cohort of intensively reared pigs over a period of two years. Nasal swab specimens were collected at monthly interval from observed clinical cases of influenza like illness in pigs and pig handlers. Samples were analyzed by real time RT-PCR and isolation in chicken embryonated eggs. A total of 227 clinical cases of influenza like illness were observed among pigs out of which 31 (13.7%) were positive for influenza A matrix gene by real time RT-PCR. Virus isolation yielded 29 (12%) isolates out of which 18 (18%) were identified as influenza A/H1N1 by Heamaglutination Inhibition test using H1 antisera. RT-PCR positive samples were subtyped as 2009 pandemic A/H1N1 with subtype specific primers and probes. This is the first report of detection and isolation of pandemic influenza H1N1 from pigs in Nigeria. Continuous circulation of this virus in pigs may cause reassortments with seasonal influenza or mutations and substitutions in the gene that may result in the emergence of novel or pandemic influenza virus of economic and public health importance. Nigeria is considered a geographical hotspot of zoonotic diseases, which necessitate active surveillance and monitoring of emerging pandemic threats.

HBV infectivity among Nigerians

The study involved 60 (non-immunized), 14 (immunized against HBV), healthy Nigerian adults and 28 Nigerian patients with hepatitis. Their sera were tested for HBsAg, HBeAg, anti-HBe, anti-HBc, anti-HBs and anti-HCV while only 15 subjects with chronic hepatitis had HBV DNA assay by PCR. The subjects aged 21 to 72 years and comprised 75 male and 27 female adults. The prevalence of HBV infection by HBsAg and/or anti-HBc sero-positivity was 55.9%. Only HBsAg and anti-HBs were detectable in 21% each among immunized while HBsAg, HBeAg, anti-HBe, anti-HBc, anti-HBs were present in 58%, 20%, 6%, 32%, and 42% respectively in the non-immunized subjects. HBV DNA was positive in 86.7% of the 15 subjects. About fifty five percent of all subjects were infectious of HBV with 13.7%, 3.9%. 32.3% and 4.9% accounting for high, medium, low and very low infectivity respectively while 44.1% and 1% of the subjects were susceptible and naturally immuned to HBV respectively. Coinfection with HCV tends to favour HBV infectivity. In conclusion, the infectivity of HBV among Nigeria is varied but high and a great proportion of the population is susceptible.

Are patients with primary hepatocellular carcinoma infectious of hepatitis B, C and D viruses?

Primary HepatoCellular Carcinoma (PHCC) has been strongly associated with HBV and HCV infections among other aetiological factors. However; do the patients still spread the viruses? This study involved forty one Nigerian adult patients with PHCC and 45 controls who were tested for HBsAg, HBeAg, Anti-HBe, Anti-HBs, anti-HCV IgM and IgG, anti-HDV and HDV antigen using ELISA. Statistical analysis was carried out with the student - t - test and Mc Nemar test at p < 0.05. The subjects consisted of male:female ratio of 3:1 for both the PHCC patients and controls. Evidence of exposure to hepatitis B, C and D viruses was detected in 95.1%, 44% and 0% of the patients respectively while the respective values of 24%, 11.1% and 0% were obtained for the controls. Indication for high (HBeAg) and low (anti HBe) HBV viral replication, and acute HBV infection were detected in 12.5%, 92.7% and 2.2% respectively among the patients while only 35.6% of the controls had low HBV viral replication. Acute and chronic infections of HCV were also found in 26.8% and 24.4% of the patients respectively compared to the respective values of 2.2% and 11.1% of the controls. Occult HBV infection occurred in equal proportions (11%) of both the patients (31.7%) and controls (35.6%). In conclusion, infectious HBV and HCV particles are present among Nigerian patients with PHCC while HDV infection is uncommon. Hence, safe medical care should be practised for all patients with PHCC while relatives should be screened for these viruses.

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.

HIV-1 drug resistant mutations in chronically infected treatment naive individuals in the pre-ARV era in Nigeria

In Nigeria the Federal Government rolled out antiretroviral drugs for the management of HIV infection in year 2002. This study was carried out to determine the circulating antiviral drug mutations among ARV naïve patients with chronic HIV infection during the pre-ARV roll out era in the country. DNA was extracted from stored whole blood samples collected from 75 HIV positive patients attending the Medical outpatient clinic between December 1996 and November 2001. The Reverse transcriptase (RT) and the protease (PR) regions of the viral genome were amplified by nested PCR and then sequenced by cycle sequencing and analyzed using the ABI 3100 DNA sequencer to determine the mutations associated with protease inhibitors (PI), nucleoside reverse transcriptase inhibitors (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI). Ten of the 64 (15.6%) samples with positive PCR had mutations for PR inhibitors (PI) including R8D, I 15V, G16E, M36I, M46L, L63P and H69K, while 5 of 63 harbored RT inhibitor (NRTI/NNRTI); V179I, A98T, V179E and A98S. Detection ofARV drug resistant mutations when ARV was not known to be in use in Nigeria calls for caution in the interpretation of drug resistance profile of HIV-1 from infected persons on treatment ARVs in the country.

Correlation of cag-A serological status with histological parameters of chronic gastritis among dyspeptic patients in south western Nigeria

BACKGROUND

The aim of this study was to determine the sero-prevalence of Cag-A strains of Helicobacter pylori in both dyspeptic and non-dyspeptic individuals and also correlate the serological status of Gag-A strain of H. pylori with the various graded histological variables of chronic gastritis in the dyspeptic patients.

METHODS

Using helicobacter p120 Cag-A enzyme linked immunosorbent assay, Cag-A serology test was carried out on 65 dyspeptic patients and 65 age and sex matched non-dyspeptic controls. The gastric biopsies of the patients were also histologically examined to ascertain the presence, nature and degree of the following histological variables of gastritis: colonisation by H. pylori; inflammation, intestinal metaplasia and mucosal atrophy. The CagA serological status was then correlated with the graded variables.

RESULTS

A prevalence of 46.2% and 58.8% seropositivity for Cag-A strain of H. pylori was found among dyspeptic patients and control individuals respectively. Cag-A seropositive patients accounted for nine(81.8%) of the 11 cases with moderate to severe activity and 75% of both cases with mucosal atrophy and cases with intestinal metaplasia.

CONCLUSION

Infection with Cag-A positive Helicobacter pylori was equally prevalent among both dyspeptic patients and control subjects studied. CagA seropositivity, however, appeared to be associated with higher inflammatory activity in the mucosa of patients with chronic gastritis and may be associated with intestinal metaplasia and mucosal atrophy in H. pylori-induced chronic gastritis.

Correlation of serum anti-helicobacter pylori immunoglobulin a (IgA) with histological parameters of chronic gastritis in ibadan, Nigeria

BACKGROUND

The seroprevalence of anti-H. pylori IgA antibodies has been reported to vary among populations and in relation to strains of Helicobacter pylori bacterium. However, there has been conflicting reports on the association between IgA serological status and the histological variables of chronic gastritis. This study was therefore conducted to clarify this relationship.

METHOD

Using an ELISA based commercial kit, anti-H. pylori IgA antibody tests were performed on 65 dyspeptic patients and 65 age- and sex-matched controls. The gastric biopsies of these patients were also examined histologically for the degrees of inflammation, activity, intestinal metaplasia and atrophy. The CagA status of the patients had been determined previously.

RESULTS

There was an anti-H. pylori IgA antibody prevalence of 67.7% in dyspeptics and 56.9% in non-dyspeptic individuals. No correlations were observed between serum H. pylori IgA antibody and the graded parameters of chronic gastritis in dyspeptic patients, although twice more patients with mild gastric inflammation were found among IgA positive than among IgA negative patients. However, a statistically significant relationship was established between serum IgA positivity and the CagA status of the patients (p = 0.028).

CONCLUSION

The seroprevalence of anti-H. pylori IgA antibody is high in our environment. Serum IgA status may be associated with milder degrees of gastritis in our patients but a larger cohort of patients is needed to confirm this. There seems to be a good agreement between serum IgA and CagA statuses among dyspeptic patients.

Genital ulcer diseases among HIV-infected female commercial sex workers in Ibadan, Nigeria

We evaluated the prevalence and association of Genital Ulcer Diseases (GUDs) among HIV-1 infected female commercial sex workers (FCSWs) in Ibadan, Nigeria. A total of 250 FCSWs from brothels in Ibadan were tested for presence of antibodies to HIV and Syphilis. Pelvic examinations for signs of sexually transmitted infections (STIs) were carried out on the subjects. Endocervical and high vaginal swabs were collected from each of the subjects to establish laboratory diagnosis of STIs. Their age ranged from 15 to 55 years (Mean = 25.8 yrs; SD = 3.74). Majority (246/250) were Nigerians, while 1.6% were from neighboring West African countries. Sixty four (25.6%) of the subjects were positive for HIV-1 while seven (2.8%) had dual HIV-1/2 infection. Analysis of the STIs showed that 49 (19.6%) of the CSWs had GUDs. Herpes genitalis was the commonest GUDs as it occurred in 25 (10%) of the subjects. Other STIs identified were chancroid (5.6%), syphilis (4.0%) and lymphogranuloma venerum (LGV) (4%). Sixteen (64.0%) of the CSWs with herpes genitalis had HIV-1 infection. The risk ratio of herpes genitalis for HIV acquisition was 3.0 (95% CI: 2.0 - 4.4). Syphilis and chancroid were also found tobe significantly associated with increased risk of HIV infection (p < 0.0001). The adjusted odd ratios for Herpes genitalis, chancroid, and syphilis were 3.7 (1-13.0, p < 0.05), 19.8 (2.7-13.0, p < 0.05) and 19.1 (1-231.0, p < 0.05) respectively. There is need to educate FCSWs continually to adopt safer sexual behaviours, seek early diagnosis and treatment of GUDs to reduce their risk of transmitting HIV infection.

Pitfalls in diagnosis of hepatitis B virus infection among adults Nigerians

OBJECTIVE

Hepatitis B virus infection is common in Nigerians and its diagnosis is necessary for effective treatment and eradication. This study is aimed at highlighting the serological factors jeopardizing the diagnosis and treatment of the infection among Nigerians adults.

PATIENTS AND METHODS

Three studies were carried out. The first study involved 56 Nigerian adults and it compared the assay of HBsAg by Haemagulation Method (HMA) with Enzyme linked immunoassay (ELISA). The second study was a comparison of Glaxo Welcome HB rapid test(GWHB) with ELISA in sero-assay of HBsAg and HBeAg among 25 Nigerian subjects while the third study was on the assay of the sera of HBsAg positive patients for HBeAg and anti-HBe in forty two Nigerian patients by ELISA.

RESULTS

The sero - prevalence rates of HBsAg were 41.8% and 61.8% by HM and ELISA respectively with false HBsAg sero-positives and sero-negatives by HM of 5.4% and 25.5% respectively. Similarly, there was sero-detection of HBsAg in 84% and 80% by ELISA and GWHB respectively in 25 Nigerian adults. In addition, 19% and 64% of the 42 patients with HBsAg sero-positivity were also positive for HBeAg and anti-HBe respectively, while 31% of the patients were both HBeAg and anti-HBe sero-negative.

CONCLUSION

Sero-diagnosis of HBsAg and other serological markers of infectivity in patients with HBV should be carried out by ELISA rather than HMA among adult Nigerians. Furthermore, high infectivity of the virus abounds among Nigerian with HBV infection.

Risk of hepatitis B virus in the slaughter house

The study involved 180 Nigerian butchers and 180 traders (controls) selected by multistage stratified sampling who had their sera assayed for HBsAg (hepatitis B surface antigen) by enzyme-linked immunosorbent assay method. The butchers and the controls had an HBsAg sero-prevalence rate of 9.4% and 3.3%, respectively. Various risky practices were more common among the butchers but their hepatitis B antigenaemia was not related to the duration of their occupational exposure. The study shows that the butchers constitute a high risk occupation for hepatitis B viral infection.

Detection of HIV antigen and cDNA among antibody-negative blood samples in Nigeria

In developing countries as many as 50% of patients for whom a transfusion is indicated are at risk of dying immediately if transfusion is withheld. It is therefore important that blood transfusion is made as safe as possible. This study was designed to assess the safety of blood transfusion in two large blood banks in Ibadan, Nigeria. Aliquots of 250 samples already screened and passed as negative for HIV-1 and -2 were collected from each of the blood banks. Samples were tested for the presence of HIV-1 antigen (ELAVIA Ag I) and the antigen-positive samples tested for the presence of specific HIV-1 antibodies by Western blot (BioRad, France). All antigen-positive samples were also subjected to PCR. HIV-1 antigen was detected in 6 (1.2%) of the 500 samples, of which 4 (0.8%) and 3 (0.6%) were Western blot-indeterminate and PCR-positive, respectively. Transfusion of HIV-contaminated blood may be contributing significantly to the spread of the virus in Nigeria. There is therefore an urgent need for an organized blood-banking system with facilities for more sensitive assays for the detection of HIV in blood to prevent transmission through transfusion.

Nigerian butchers and hepatitis B virus infection

Various target groups have been identified in Nigeria for studying the prevalence of hepatitis B virus infection; however there is no information on its prevalence among workers in slaughter houses. This study determined the seroprevalence of hepatitis B virus infection in Nigerian butchers at Ibadan, and comprised 360 healthy Nigerian adult subjects (180 butchers, 180 traders as controls) selected by multistage stratified sampling. A questionnaire was used to collect relevant information and included points about risk behaviour. ELISA was used to detect the hepatitis B surface antigen in the serum; the seroprevalence rate in butchers and controls was 9.4% and 3.3%, respectively (p<0.05). Risk behaviour was seen more commonly in butchers than in controls. The presence of hepatitis B surface antigen in the serum was not related to the duration of occupational exposure or the number of partners. In summary, butchers comprise a high-risk occupational group for exposure to hepatitis B virus infection. We conclude that routine screening for parenterally acquired infections in this group is thus necessary in order to identify those who will require treatment and immunisation, especially against hepatitis B virus infection.

HIV infection among patients with pulmonary tuberculosis in Nigeria

Respiratory problems like Pneumocystic carinni and Pulmonary tuberculosis (PTB) are among the common opportunistic infections in patients with HIV/AIDS. The risk of acquiring Mycobacterium tuberculosis in a community becomes greater with increase in the number of HIV positive persons with active tuberculosis. This study was carried out to determine the magnitude of HIV infection among PTB patients in different parts of Nigeria as part of the year 2000 national HIV surveillance programme. Blood samples were collected on blotting paper from a total of 2826 individuals attending TB clinics between 1st of September and 1st November, 2000. Samples were collected from patients with confirmed PTB from 12 states in the 6 geopolitical/health zone (2 states/zone) of Nigeria as part of high risk sentinel population groups. Samples were tested for the presence of HIV antibodies using commercial ELISA (Genescreen HIV-1/2, Sanofi Pasteur, Paris). All initially reactive samples were retested with a rapid EIA (Gene II, Sanofi Pasteur, Paris) according to the WHO recommendations (option II). HIV Prevalence in the states varied from 4.2% in Oyo to 35.1% in Benue States with a median prevalence of 17.0%. HIV Prevalence increased with age to a peak of 23.9% among PTB patients 30-39 years and then declined progressively to 12.8% among those 60 years and above. A relatively high HIV infection rate (13.8%) was found among the young adolescent age group 10-19 years. There was no significant difference in the rate among male and female PTB patients tested. Comparison with results of previous HIV sero-surveys shows a steady increase in HIV prevalence among PTB patients over the years. The high prevalence of HIV among young PTB patients aged 10-19 years in this study is worrisome and must be noted for intervention.

Reliability of testing and potential impact on HIV prevention in Nigeria

Several factors including variability of human immunodeficiency virus (HIV), laboratory facilities, cost and competence of personnel handling the tests are some of the important factors that affect accuracy and reliability of HIV testing in most parts of Africa. Recently investigators in Africa have observed that antibody detection assays based on antigens derived from HIV-1 subtype B show moderate to significantly lower sensitivity for detection of infection by various non-B subtypes. In this study, we evaluated the reliability of two EIA and 12 rapid HIV-1/2 test kits that are commercially available in Nigeria using the Western immunoblotting technique as reference. A panel of 100 sera from Western blot confirmed symptomatic or asymptomatic HIV-1 infected persons and 90 seronegative patients from those referred for testing in our laboratory were used for this study. Each sample was tested with two HIV-1/2 EIA, and 12 HIV-1/2 rapid test kits commercially available at one time or the other for HIV-1/2 testing in Nigeria. Overall, the sensitivity of the two EIA kits were 100% and 91.0% with specificity of 96.7% and 91.1% respectively. The sensitivity of the rapid test kits ranged from 88% to 98.0% with specificity of 92.2% to 100%. Further analysis showed significant variation in the sensitivity and specificity of the same kit based on whether an individual had asymptomatic or symptomatic infection The results of this study highlight the problem of diagnosis of HIV infections in Africa. It shows that the sensitivity of most of the rapid assays shall not be adequate for detection of early infection. The implications of possible misdiagnosis on the various intervention strategies that rely predominantly on correct HIV status of an individual are enormous. Thus, there is an urgent need for review of the current HIV testing assays or algorithms in Nigeria and other parts of Africa.

Mother-to-child transmission of different HIV-1 subtypes among ARV Naïve infected pregnant women in Nigeria

The rate of mother-to-child transmission (MTCT) of HIV as well as the implications of the circulating multiple subtypes to MTCT in Nigeria are not known. This study was therefore undertaken to determine the differential rates of MTCT of HIV-1 subtypes detected among infected pregnant women before ARV intervention therapy became available in Nigeria. Twenty of the HIV-positive women who signed the informed consent form during pregnancy brought their babies for follow-up testing at age 18-24 months. Plasma samples from both mother and baby were tested for HIV antibody at the Department of Virology, UCH, Ibadan, Nigeria. All positive samples (plasma and peripheral blood mononuclear cells-PBMCs) were shipped to the Institute of Tropical Medicine, Antwerp, Belgium, where the subtype of the infecting virus was determined using the HMA technique. Overall, a mother-to-child HIV transmission rate of 45% was found in this cohort. Specifically, 36.4%, 66.7% and 100% of the women infected with HIV-1 CRF02 (IbNg), G and B, respectively, transmitted the virus to their babies. As far as it can be ascertained, this is the first report on the rate of MTCT of HIV in Nigeria. The findings reported in this paper will form a useful reference for assessment of currently available therapeutic intervention of MTCT in the country.

Neutralizing antibodies against poliovirus serotypes among children in southwest Nigeria

In May 1988, the World Health Assembly resolved to eradicate poliomyelitis globally by the year 2000. Despite the reported success in national immunization days, acute flaccid paralysis surveillance and accelerated efforts to meet the deadline including 'mopping-up' were executed in 1999 and subsequent years. Nigeria remains one of the major reservoirs for wild poliovirus transmission. Neutralizing antibody titre to the three poliovirus serotypes was determined among children from different communities in southwest of Nigeria, and analysed by age, gender and location. About 0.5-2 ml of blood sample was collected by venepuncture from each child. Aliquot of serum from each blood sample was inactivated prior to neutralization test by the beta method for poliovirus antibodies. A total of 347 (59.6 per cent) out of 500 and 82 children enrolled for the study had at least antibody titre of 1:8 against each of the three poliovirus serotypes. Immunity level to the three poliovirus serotypes increased with age and peaked in children aged 4-6 years. Seven (53.8 per cent) out of 13 unvaccinated children tested in the study had detectable neutralizing antibody to the three serotypes. Immunity pattern of P2 > P1 and P3 was observed but no correlation between gender and antibody to the poliovirus serotypes. The populations had 59.6 per cent herd immunity for the three poliovirus serotypes. In a country with high incidence of poliomyelitis this situation leaves a high number of non-immunized children at the risk of infection with one or more poliovirus serotypes.

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.

Oro-facial lesions and CD4 counts associated with HIV/AIDS in an adult population in Oyo State, Nigeria

OBJECTIVE

The objective of this study was to define the oro-facial lesions associated with Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS) in an adult population in Oyo state, Nigeria and to relate these with the level of immune suppression as measured by the CD4 counts.

MATERIALS AND METHOD

The study population consisted of 679 consecutive subjects who were seen at the state-owned blood bank. Information on demography, medical and medication histories were obtained. Oro-facial examinations were carried out according to Greenspan et al [Oral Surg Oral Med Oral Pathol (1992)73:142-144]. HIV sero-prevalence status was determined for all patients. CD4+ T-lymphocyte count was carried out for those sero-positive for HIV and 31 randomly selected HIV-negative subjects. Data were analyzed using the chi-square test, Fisher's exact test, Student's t-test and odds ratio where appropriate.

RESULTS

Eighty-one (11.9%) of the entire study sample were confirmed HIV positive. The prevalence of specific oral lesions by HIV sero-status revealed that pseudomembranous oral candidiasis and angular cheilitis occurred significantly and more frequently in HIV-positive subjects (33.3 and 21% respectively) than those who were HIV negative (4.3 and 1.8% respectively, P < 0.05). The mean CD4 count of the HIV-positive subjects was 452 cells mm(-3), s.d. 137, while it was 602 cells mm(-3), s.d. 251, for the HIV negatives. The difference was statistically significant (P = 0.000). Forty-four (66.7%) subjects with CD4 counts <500 cells mm(-3) had oro-facial lesions whereas among those with CD4 counts >500 cells mm(-3) only 22 (33.3%) had oro-facial lesions (OR = 4.57).

CONCLUSION

The type of oro-facial lesions most commonly associated with HIV/AIDS in Oyo state, Nigeria, has been shown to be pseudomembranous oral candidiasis. This was followed by angular cheilitis. These lesions, although found in HIV-negative subjects, were in a lower proportion as compared with HIV-positive subjects. Mean CD4 counts were lower in HIV-positive subjects and this was associated with greater prevalence of oro-facial candidiasis and angular cheilitis.

Evaluation of modified short course chemotherapy in active pulmonary tuberculosis patients with human immunodeficiency virus infection in University College Hospital, Ibadan, Nigeria--a preliminary report

Over the period, 1st October 1999 to 30th April 2002 a clinical trial of the modified short-course chemotherapy (SCC) in newly diagnosed cases of pulmonary tuberculosis with human immunodeficiency virus (HIV) infection in Ibadan, Nigeria was carried out. The modified SCC used was adopted by World Health Organisation (WHO)/International Union against Tuberculosis and Lung Diseases (IUALTD) for developing countries and also by the Nigerian National Tuberculosis and Leprosy Control Programmed (NTLCP). The regimen used consisted of ethambutol (E), isoniazid (H), rifampicin (R) and pyrazinamide (Z) in the intensive phase of 2 months. The continuation phase was 6 months of ethambutol (E) and isoniazid(H), i.e. 2EHRZ/6EH. Sputum conversion was 90% at the second month of treatment and there was no bacteriological relapse after 18 months of follow-up. Side effects were few and consisted mainly of acne vulgaris in 20 (22.5%) of 89 patients during the continuation phase. It is concluded that this modified 8-month chemotherapy regimen adopted by NTLCP is efficacious in treatment of smear positive pulmonary tuberculosis (PTB) patients with background HIV infection.

Hepatitis B and C viral markers in patients with sickle cell disease in Ibadan, Nigeria

Serum samples from 180 Sickle Cell Disease (SCD) patients attending Medical Out patients (MOP) clinic of the Department of Haematology, UCH, Ibadan, Nigeria were tested for the presence of HbsAg and anti-HCV in their blood samples. The result showed that HBV infection was slightly higher (not significant) than HCV infection among SCD patients (P>0.05). In addition, the result showed that the mean number of transfusion was higher among patients who were sero-positive for both HbsAg (5.0 +/- 6.6) and anti-HCV (4.6 +/- 6.7) when compared to patients who were negative for both viruses (2.7 +/- 3.0 and 2.9 +/- 3.2) for HBsAg and anti-HCV respectively. These observations is an indication that there is an urgent need to screen blood units for hepatitis B and C virus infections prior to transfusion in order to reduce HCV infection among SCD patients in Nigeria. Furthermore, it suggests the need to vaccinate SCD patients against HBV in this environment.

Prevalence of hepatitis B virus surface antigen (HBsAg) in patients undergoing extraction at the University College Hospital, Ibadan

Hepatitis B Virus (HBV) infection and its sequelae (liver chirrhosis and hepatic carcinoma) are endemic in Africa. The risk of transmission of the infection during dental treatment is real. This study was carried out to determine the rate of Hepatits B Surface Antigen (HBsAg) as a marker of hepatitis B virus infection in patients undergoing dental extraction in order to highlight the potential risk of nosocomial transmission among the Dental Health Workers (DHW) and their patients. Three hundred (143 males and 157 females) consecutive patients requiring dental extraction who volunteered were enrolled into this study. Their ages ranged from 11 years to 95 years with a mean of 37.2 years (SD = 16.725) and a median of 36 years. The overall HBsAg infection rate was 18.3% (55/300). A higher infection rate (23.1%) occurred among the male patients compared with 14% in females (p = 0.0086). The high rate of HBV infection found among this study population suggests that Dental Surgeons in this environment have a high risk of exposure to hepatitis B virus and should be immunized at the beginning of their professional life. Universal biosafety measures should be observed strictly in all invasive procedures.

Human immuno-deficiency virus (HIV) infection among oral surgery patients at the University College Hospital, Ibadan, Nigeria

The Human Immuno-deficiency Virus is a World-wide epidemic and evidence abound that the infection is spreading rapidly in sub-Saharan Africa with little or no control. Nosocomial transmission of HIV in the Dental Surgery has been documented. This study was undertaken to determine the prevalence of HIV among dental patients undergoing extraction at the University College Hospital, Ibadan. Three hundred patients requiring dental extraction at the dental clinic, UCH, Ibadan who consented were enrolled for the study. Blood samples from these individuals were tested for the presence of HIV antibodies using commercially available ELISA (Monolisa Sanofi, Pasteur, France). All initially reactive samples were confirmed by a commercial Western immunoblot assay (Bio-Rad Norapath HIV kit). A prevalence of 2.3% (7/300) was obtained among individuals tested for this study. Four (2.8%) of the 143 males and 3 (1.9%) of 157 females were positive for HIV antibodies. All the seropositive patients except one were within the age range 20-39 years and most of them (6 out of 7) do not use condom during intercourse. More than half (57%) of the patients had more than one sexual partner. This study shows that the risk of transmitting HIV to DHCW during treatment is also a potential hazard in this environment. Hence, adequate preventive measure should be observed always.

Serum hepatitis C virus and hepatitis B surface antigenaemia in Nigerian patients with acute icteric hepatitis

Acute hepatitis is common in Nigeria and hepatitis B virus (HBV) infection has been a major aetiological factor. However, the role of Hepatitis C Virus (HCV) infection is yet undetermined. Forty-five consecutive Nigerian patients with Acute Icteric hepatitis (AIH) attending the Medical Clinic of the University College Hospital, Ibadan, Nigeria and 45 healthy adult Nigerians (controls) were studied for evidence of infection with both viruses. Questionnaire on risk procedures which predispose to acquisition of both HBV and HCV infections were administered to the patients. Blood samples were collected from all the subjects and tested for antibody to HCV (Anti-HCV) and Hepatitis B surface Antigen (HBsAg) using the second generation Enzyme Linked Immunoassay (Monolisa -R, Sansofi, Pasteur; France). Anti-HCV was detected in 21(47%) and 17(38%) of the patients and controls respectively. The corresponding prevalences of HBsAg were 38(84%) and 11(24%), p < 0.001. Hepatitis B virus infection was found to occur more than HCV infection in the patients with AIH but similar among the controls. Combined HBV and HCV infection occurred more frequently among the patients (42.1%) than in the control (11%) (; < 0.001). Although there was no significant difference in the HCV infection between the two groups, isolated HCV infection is commoner in the control than in the patients with AIH, (p < 0.001). Similarly, single HCV infection is commoner than lone HBV infection among the control, p < 0.05. In summary, this study shows that while both HBV and HCV infections are common in Nigeria, AIH may be more associated with HBV than HCV in the country.

Phylogenetic analysis of new hepatitis B virus isolates from Nigeria supports endemicity of genotype E in West Africa

Isolates of hepatitis B viruses were collected from 20 acute and chronic hepatitis patients in a highly endemic region of Nigeria. Sequencing classified the isolates to the ayw4, as they all contained the amino acid variations characteristic for that serotype. In the pre-S2 region of five isolates, three to seven amino acids were deleted, suggesting that immune escape mutations previously associated only with chronic HBV infection may be observed also in acute disease. Phylogenetic analysis of the complete pre-S2/S (large S) genes (831 nt) demonstrated that all the viruses belonged to the same genotype E. So far, no isolates of genotype E have been found in any other region of the world, including the Americas. This may suggest a relatively recent introduction of this genotype into humans and would explain the relatively low genetic diversity of viruses belonging to this genotype. One genotype E virus had been found previously in a chimpanzee, and viruses belonging to the CHIMP genotype are related to other genotype E viruses. These findings are compatible with a transmission of genotype E viruses from chimpanzees to humans.

Antibodies to Lassa virus Z protein and nucleoprotein co-occur in human sera from Lassa fever endemic regions

It is not known whether the small 11-kDa Z protein of Lassa virus is immunogenic during human Lassa virus infection. To obtain evidence for the existence of an antibody response and to test the suitability of these antibodies for serosurveys, sera from Lassa fever endemic regions (Guinea and Nigeria, n = 75) were tested for co-reactivity to Z protein and nucleoprotein (NP). Sera from a non-endemic region (Uganda, n = 50) served as a specificity control. Z protein and NP were expressed in Escherichia coli, affinity-purified, and used as antigen in Western blot. Indirect immunofluorescence (IIF) with Lassa virus-infected cells was performed for comparison. Due to high unspecific reactivity of the African sera, Western blot testing was performed with a 1:1,000 serum dilution. Under these conditions, none of the control sera but 12% of the sera from endemic regions co-reacted with both Z protein and NP. Reactivity to Z protein was significantly associated with NP reactivity (P < 10(-6)). NP and Z protein-specific antibodies were co-detected in 33% of the IIF-positive sera and in 5% of the IIF-negative sera (P = 0.001). These data provide evidence for appearance of antibodies to Z protein and NP following Lassa virus infection. A recombinant blot for detection of both antibody specificities seems to be specific but less sensitive than IIF.

Human T-cell lymphotropic virus types I and II infections in mother-child pairs in Nigeria

A community-based survey to determine the prevalence of human T-cell lymphotropic type I (HTLV-I) and type II (HTLV-II) virus infections in mothers and children in south-western Nigeria was carried out using blood samples collected in 1993. A multistage cluster, random sampling procedure was used to select 460 mother-child pairs (476 children because there were 16 sets of twins) from 14 enumeration areas. A commercially available, whole HTLV-I lysate antigen-based ELISA method was used to screen for HTLV-I and HTLV-II antibodies in the samples. A synthetic peptide antigen-based ELISA was then used to differentiate between antibody reactivity to either HTLV-I or HTLV-II. Reactivity to HTLV-I or HTLV-II antibodies was found in 4.3 per cent (20/460) of mothers and in 1.1 per cent (5/476) of children in both rural and urban communities and all the positive children were males. None of the 16 sets of twins in this study was positive for either HTLV-I or HTLV-II. Also none of the mother-child paired sera tested showed concordance for either HTLV-I or HTLV-II antibody positivity. The lack of concordance between mother and child sera suggests that vertical transmission may not be the major route of transmission of HTLV infection to children in south-western Nigeria. Other modes of transmission, such as the re-use of unsterilized needles for injections and surgical knives in local scarification, which are common practices in the region, need to be investigated as they may prove to be more important than vertical transmission. These findings have important implications for any control programme for diseases that can be spread by the same routes as HTLV infection (the human immunodeficiency viruses, hepatitis B, and hepatitis C infections).

Human immunodeficiency virus types 1 and 2 infection in some rural areas of Nigeria

The prevalence of human immunodeficiency virus types 1 and 2 in rural areas of Nigeria was estimated using 1089 sera collected in 18 locations from 1992 to early 1994. The sera were tested with Enzyme linked Immunosorbent Assay (ELISA) and confirmed by Western Immunoblotting technique. Overall, 13 (1.2%) of the 1089 sera were positive for antibodies to HIV-1 and HIV-2. Prevalence of 0.6% and 0.8% were obtained for HIV-1 and HIV-2 respectively. The highest prevalence of HIV-1 and HIV-2 (50.0%) were found in Zuhlrrua and Umubuzu. A seroprevalence of 1.2% was obtained for both male and female groups tested. The highest prevalence of HIV was found among individuals 30-39 years age group. An overall increase in prevalence of HIV-1 and HIV-2 infection was obtained over the three years during which samples were collected for this study (0.7% in 1992, 1.0% in 1992 and 3.4% in 1994). In addition, two sera were positive for both HIV-1 and HIV-2. The detection of antibodies to HIV-1 and HIV-2 in the rural areas where blood samples were collected for this study shows that both viruses are widespread in the rural communities of Nigeria.

Prevalence and epidemiological characteristics of hepatitis B and C infections among doctors and dentists in Nigeria

A random sample of seventy five doctors and dentists at the University College Hospital, Ibadan, Nigeria, was surveyed. They were offered anonymous testing for hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), antibodies to hepatitis B core antigen (anti-HBc) and to hepatitis C virus (anti-HCV) by enzyme immunoassay. The results suggest a high prevalence of hepatitis B virus (HBV) with a high potential of transmissibility, as well as a high prevalence of HCV infection. Most of the doctors and dentists use universal precaution for protection against viral hepatitis less than 50% of the occasions when they carry out procedures on their patients. Infection with HBV was associated with type of specialty (surgeons and dentists) and lack of HBV vaccination (p < 0.05). After logistic regression, these factors were independently associated with HBV infection (p < 0.05). Sixty (80%) of these health care workers had not received prior HBV vaccination. The unvaccinated personnel were more likely to be surgeons, dentists, less than 37 years of age and have fewer years of professional activity (p < 0.05). After logistic regression, only the fewer years of professional activity remained independently associated with lack of vaccination (p < 0.05). We conclude that to reduce the occupational exposure of HBV, universal precautions must be rigorously adhered to when doctors and dentists carry out procedures on their patients. It is necessary that these health care workers are vaccinated with HBV vaccine and the currently anticipated HCV vaccination, if not immune. No recent study exists that exclusively addresses this problem in health care workers in tropical Africa.

Hepatitis B and C in doctors and dentists in Nigeria

We surveyed a random sample (n = 75) of doctors and dentists at University College Hospital, Ibadan, Nigeria. They were offered anonymous testing for hepatitis B surface antigen (HBsAg), hepatitis Be antigen (HBeAG), antibodies to hepatitis B core antigen (anti-HBc) and to hepatitis C virus (anti-HCV), by enzyme immunoassay. The results suggest a high prevalence of hepatitis B virus (HBV) with a high potential of transmissibility, as well as a high prevalence of HCV infection. The majority of the doctors and dentists use universal precaution for protection against viral hepatitis on < 50% of the occasions when they carry out procedures on their patients. Infection with HBV was associated with type of specialty (surgeons, dentists) and lack of HBV vaccination (p < 0.05). After logistic regression, these factors were independently associated with HBV infection (p < 0.05). Sixty (80%) had not received prior HBV vaccination. Unvaccinated personnel were more likely to be surgeons, dentists, < 37 years of age, and have fewer years of professional activity (p < 0.05). After logistic regression, only fewer years of professional activity remained independently associated with lack of vaccination (p < 0.05). To reduce the occupational exposure of HBV, universal precautions must be rigorously adhered to when the doctors and dentists carry out procedures on their patients, and all health-care workers should be vaccinated with HBV vaccine and the HCV vaccine, when it becomes available.

Hepatitis B and C virus and hepatocellular carcinoma

Antibody to hepatitis C virus (anti-HCV) was detected in 18.7% of patients with hepatocellular carcinoma (HCC) and in 10.9% of controls (P < 0.001). The corresponding prevalences of hepatitis B surface antigen (HBsAg) were 59.3% and 50.0% (P < 0.001). Using patients with non-hepatic disease as controls, stepwise logistic regression analysis indicated that both anti-HCV (odds ratio 6.88%; 95% confidence interval [CI] 1.63-9.77) and HBsAg (odds ratio 6.46; 95% CI 1.68-18.13) were independent risk factors for HCC. Calculation of the incremental odds ratio indicated no interaction between hepatitis B virus (HBV) and HCV. Blood transfusion was a significant risk factor for acquiring HCV infection with odds ratios of 5.48 (95% CI 1.07-29.0) and 2.86 (95% CI 1.31-22.72) for HCC cases and controls, respectively. The mean age of HCC cases with HBsAg and anti-HCV was lower than that of HCC patients with anti-HCV alone (P < 0.01). It is concluded that there is a high rate of HBV infection, and a low rate of HCV infection, among Nigerian patients with HCC. However, HBV and HCV are independent risk factors for the development of HCC, with HBV having an effect more rapidly. Screening of blood products for transfusion might minimize the risk of HCV transmission.