Diverse genetic subtypes of HIV-1 among female sex workers in Ibadan, Nigeria

Genetic diversity is the hallmark of HIV-1 infection. It differs among geographical regions throughout the world. This study was undertaken to identify the predominant HIV-1 subtypes among infected female sex workers (FSWs) in Nigeria. Methods: Two hundred and fifty FSWs from brothels in Ibadan Nigeria were screened for HIV antibody using ELISA. All reactive samples were further tested by the Western Blot Techniques. Peripheral Blood Mononuclear Cells (PBMCs) were separated from the blood samples of each subject. Fragments of HIV Proviral DNA was amplified and genetic subtypes of HIV-1 was determined by direct sequencing of the env and gag genes of the viral genome followed by phylogenetic analysis . Results: The age of the FSWs ranged from 15 to 55 years old (Mean = 25.8years, SD =3.74). Majority were Nigerians while others (1.6 %) were from neighboring West Africa countries. Four ( 1.6% ) of the FSWs were active for less than one year as sex workers, and the mean length of sex work was 2.80 years ( Range = 1.0 – 15.0 years ). Sixty-four (25.6%) of the 250 CSWs were positive for HIV-1 while 7 (2-8%) had dual infections to HIV-1 / HIV-2. Among the 34 HIV-1 strains  characterized by sequencing, 19 (55-9%) were subtype G, 9 (26.5%) CRF02_A/G, 3 (8.8%) CRF06_cpx while 1 (2.9%) each were identified as subtype C, CRF01_A/E and CRF09_cpx respectively. Nineteen (55.9%) of the FSWs with subtype G had been active in the sex work for between one to five years. The youngest of the HIV -1 infected FSWs with sexual activity of less than a year had subtype G strain. There is a significant probability that infection with this subtype occurred with a short incubation period (p< 0.05). Conclusion: This study showed a wide range of HIV- 1 subtypes among FSWs in Nigeria. The situation poses serious challenge for the design of HIV vaccine candidate for use in Nigeria.Keywords: Diverse, HIV, subtypes, Female Sex workers and Vaccin

Innate Immune Response to Rift Valley Fever Virus in Goats

Rift Valley fever (RVF), a re-emerging mosquito-borne disease of ruminants and man, was endemic in Africa but spread to Saudi Arabia and Yemen, meaning it could spread even further. Little is known about innate and cell-mediated immunity to RVF virus (RVFV) in ruminants, which is knowledge required for adequate vaccine trials. We therefore studied these aspects in experimentally infected goats. We also compared RVFV grown in an insect cell-line and that grown in a mammalian cell-line for differences in the course of infection. Goats developed viremia one day post infection (DPI), which lasted three to four days and some goats had transient fever coinciding with peak viremia. Up to 4% of peripheral blood mononuclear cells (PBMCs) were positive for RVFV. Monocytes and dendritic cells in PBMCs declined possibly from being directly infected with virus as suggested by in vitro exposure. Infected goats produced serum IFN-γ, IL-12 and other proinflammatory cytokines but not IFN-α. Despite the lack of IFN-α, innate immunity via the IL-12 to IFN-γ circuit possibly contributed to early protection against RVFV since neutralising antibodies were detected after viremia had cleared. The course of infection with insect cell-derived RVFV (IN-RVFV) appeared to be different from mammalian cell-derived RVFV (MAM-RVFV), with the former attaining peak viremia faster, inducing fever and profoundly affecting specific immune cell subpopulations. This indicated possible differences in infections of ruminants acquired from mosquito bites relative to those due to contact with infectious material from other animals. These differences need to be considered when testing RVF vaccines in laboratory settings

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 simulatehuman 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 vaccinesfor 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 withCaprine Arthritis 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 (RTPCR) 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 theenvelope 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 studyshowed 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 HIVneuropathology. 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

Tumour markers and hepatitus C virus infection in Nigerian patients with liver diseasse

No Abstract. Nigerian Journal of Medicine Vol. 15 (4) October-December 2006: 417-42

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 prevalence 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

HELICOBACTER PYLORI SEROLOGY AND EVALUATION OF GASTRODUODENAL DISEASE IN NIGERIANS WITH DYSPEPSIA

Helicobacter pylori (H. pylori) has been strongly associated with various gastroduodenal diseases worldwide with only a few studies emanating from developing countries. The objectives of this study were to determine the prevalence of serum Immunoglobulin G (IgG) and underlying gastroduodenal pathology in Nigerian patients with dyspepsia and ascertain the usefulness of H. pylori IgG screening in decreasing endoscopic workload in dyspeptics in Nigeria. Fifty-five patients with dyspepsia and 55 age and sex-matched apparently normal control were screened for H. pylori IgG using ImmunocombRII kits. Each of the 55 patients was also examined endoscopically with biopsies taken appropriately. Serology was positive in 94.5% and 92.7% of dyspeptic patients and controls respectively. Gastroduodenal inflammation was the commonest endoscopic finding, 43 (78.18%). Other findings were malignant gastric tumour 6(10.9%), reflux oesophagitis 3 (5.45%), gastric ulcer 2 (3.64%), and duodenal ulcer in 1 (1.82%). Chronic gastritis was the main histopathologic finding in the dyspeptic patients. It is concluded that serum H. pylori IgG cannot be used as a screening procedure to reduce endoscopic workload in Nigerian patients with dyspepsia. Key Words: dyspepsia; Helicobacter pylori serology; gastroduodenal disease African Journal Of Clinical And Experimental Microbiology Jan 2004 Vol.5 No.1 131-13

Sero-prevalence of hepatitis C virus amoung patients attending STD clinic in Ibadan, Nigeria

In the tropics, hepatitis C virus (HCV) seroprevalence ranges from < 0.2% in whole Africa. A strong association between HCV and hepatitis B surface antigen (HBsAg)-negative chronic liver disease and hepatocellular carcinoma has been described. Hepatocellular carcinoma (HCC) is one of the most common cancers among Africans, and in Nigeria by 1970 the estimated rate was 6.6 per 100,000 populations per annum. Sexual transmission was regarded as a minor cause of HCV, the degree of which has not been properly evaluated in most environments. Since it has been established that sexual transmission is an important mode of acquisition of the infection, we therefore set out to find the seroprevalence of HCV among 95 patients attending sexually transmitted diseases (STD) clinic in University College Hospital, Ibadan, Nigeria with a view to recommending preventive and control measures of HCV in our community. The sera collected from these respondents were used for screening for syphilis using the VDRL test, and for HCV antibodies using the MONOLISA anti-HCV (Sanofi, Pasteur France). Mid-stream urine was collected from all participants, and urethral swabs from all male participants while endocervical and high vaginal swabs were collected from female participants. Ulcer swabs were collected from those with genital ulcers. The prevalence of HCV infection was found to be 37.9% in patients presenting with STDs. This comprised 38.9% of males and 61.1% females. This prevalence rate is very high compared with the rate in the general population and other “high-risk” groups in previous studies in the same environment. Factors associated with HCV infection in this environment include high heterosexuality, high level of education, and previous instrumentations such as in scarifications and termination of pregnancy. Prevention and control of STDs will definitely reduce HCV infection and hence the attendant consequences, particularly hepatocellular carcinoma, in our environment. Afr. J. Clin. Exper. Microbiol. Vol.6(1) 2005: 53-5

A monoclonal blocking ELISA to detect chicken anaemia virus antibodies in Nigerian poultry

To provide a rapid, easy and economical method for detecting antibodies to chicken anaemia virus (CAV) especially in large numbers of chicken sera, we established a monoclonal blocking enzyme-linked immunosorbent assay (MBE). A monoclonal antibody (MAb), 2A9, directed against the 52 kDa protein of the Cuxhaven-1 CAV strain was used. The blocking ELISA depends on the selective inhibition of the binding of MAb 2A9 to solid-phase antigen by CAV-specific antibodies present in convalescent chicken serum. Performance evaluation of the MBE using 417 sera from Nigerian and Northern Ireland commercial chicken flocks revealed a 99.3 % agreement between the MBE and the IDEXX ELISA (IDE) while an 86.1 % agreement was obtained between the MBE and the indirect ELISA using 310 chicken sera. An epidemiological survey for CAV antibodies using the developed MBE on 641 sera from chicken flocks in southwest Nigeria revealed 59.0% prevalence. The MBE was found to have advantages in terms of cost, time and labor compared with the IDE and the indirect ELISA

Prevalence of measles neutralizing antibody in children under 15 years in Southwestern Nigeria

The immune status of children under 15 years in the Southwestern region of Nigeria against measles virus was determined using the neutralization test with a view to assessing the herd immunity to the virus in these communities. A total of 256 serum samples collected from children were tested by the beta method of neutralization. Forty (15.6%) of these samples were found to be positive at a titre of 1:256, 35 (13.7%) at 1:128, 36(14.1%) at 1:64, 37(14.5%) at 1:32, 38 (14.8%) at 1:16, 27 (10.5%) at 1:8 and 16 (6.3%) at 1:4. Twenty-seven (10.5%) of the 256 samples had no detectable antibody to the measles virus. There was no significant relationship between the antibody titre to measles virus and the gender of the children (p > 0.05). Also, there was no significant difference using Chi square analysis between the neutralizing antibody titres and the age of the children (p > 0.05). All the children whose samples were tested were vaccinated against measles as attested to by their parents. However, the vaccination does not seem to protect all the children, for some of them had no detectable neutralizing antibody while some had low neutralizing antibody titre. In Nigeria, where only a single dose of measles vaccine is given at 9 month, measles may remain a serious threat to the children population with its attendant high morbidity and mortality. Key Words: Prevalence, Neutralizing antibodies, Children < 15years Afr. J. Clin. Exper. Microbiol. Vol.6(1) 2005: 60-6