Armed conflict, a neglected determinant of childhood vaccination: some children are left behind.

Vaccination is an indisputable intervention that has tremendously mitigated the global burden of vaccine-preventable diseases (VPDs). The number of armed conflicts globally seems to be at an all-time high, with devastating effects on vaccination coverage. This paper will examine how armed conflicts affect childhood vaccination and lead to the reemergence and spread of VPDs. Unarguably, socioeconomic factors, population demographics, the apparent long vaccination timetable, multiple vaccine doses, lack of trust in vaccination processes and the rumor of the adverse effects of some vaccines unnerve some parents and create a puzzle. By bringing under the global floodlight, the impact of armed conflicts which contextually affect vaccination coverage, this article will help strengthen the advocacy for vaccination, and call for the fortification of existing treaties on the rule of engagement during conflicts. In order to eliminate or eradicate VPDs, strategies to reach children that are left behind during conflicts is paramount.

HIV point-of-care diagnostics: meeting the special needs of sub-Saharan Africa.

Sub-Saharan Africa, accounting for 70% of the 35 million people living with HIV worldwide, obviously carries the heaviest burden of the HIV epidemic. Moreover, the region's poor health system occasioned by limited resources and inadequate skilled clinical personnel usually makes decentralization of HIV care difficult. Therefore, quality diagnostics that are easy to use, inexpensive, and amenable for use at point of care (POC) are a dire necessity. Clearly, such diagnostics will significantly lessen the pressure on the existing over-stretched centralized HIV laboratory services. Thankfully, some POC diagnostics are already being validated, while others are in the pipeline. As POC test kits emerge, implementation hurdles should be envisaged and planned for. This review examines emerging HIV diagnostic platforms, HIV POC product pipelines, gaps, perceived POC implementation challenges, and general recommendations for quality care.

H3Africa: a tipping point for a revolution in bioinformatics, genomics and health research in Africa.

BACKGROUND: A multi-million dollar research initiative involving the National Institutes of Health (NIH), Wellcome Trust and African scientists has been launched. The initiative, referred to as H3Africa, is an acronym that stands for Human Heredity and Health in Africa. Here, we outline what this initiative is set to achieve and the latest commitments of the key players as at October 2013. FINDINGS: The initiative has so far been awarded over $74 million in research grants. During the first set of awards announced in 2012, the NIH granted $5 million a year for a period of five years, while the Wellcome Trust doled out at least $12 million over the period to the research consortium. This was in addition to Wellcome Trust's provision of administrative support, scientific consultation and advanced training, all in collaboration with the African Society for Human Genetics. In addition, during the second set of awards announced in October 2013, the NIH awarded to the laudable initiative 10 new grants of up to $17 million over the next four years. CONCLUSIONS: H3Africa is poised to transform the face of research in genomics, bioinformatics and health in Africa. The capacity of African scientists will be enhanced through training and the better research facilities that will be acquired. Research collaborations between Africa and the West will grow and all stakeholders, including the funding partners, African scientists, scientists across the globe, physicians and patients will be the eventual winners.

Molecular characterization of hepatitis A virus isolates from Nigeria.

OBJECTIVE: Despite the endemicity of hepatitis A virus (HAV) in Nigeria, genetic information on the HAV genotypes/subgenotypes circulating in the country remains unknown. The objective of this study was to investigate HAV strains using molecular epidemiological and genetic analyses among apparently healthy adult Nigerian subjects. METHODS: Testing for HAV-RNA was performed on 114 serum samples by the reverse transcription-polymerase chain reaction and sequenced with primers encompassing the VP1/P2A junction. RESULTS: Twelve serum samples tested were found to be HAV-RNA positive. Phylogenetic analysis revealed that all 12 HAV isolates were classified as subgenotype IA exhibiting 98.3% nucleotide identity. Interestingly, the Nigerian HAV/IA subgenotype consisted of two distinct genomic sublineages with a unique majority (n = 11) corresponding to strains endemic in Cameroon and the other (n = 1) shows a probable link with European sequences. Predicted conserved amino acid sequences and the few deduced substitution in the VP1/P2A junction might play a role in the development of a novel Nigerian-Cameroon sublineage within the HAV/IA subgenotype and might explain the stability of HAV/IA in this subregion. CONCLUSION: This study reveals the development of a new HAV/IA sublineage in the Nigerian-Cameroon subregion. The presence of a single subgenotype indicates that this HAV strain has been predominantly circulating in Nigeria.

Genetic analysis of hepatitis A virus variants circulating among children presenting with acute diarrhea in Cameroon.

Molecular investigation was undertaken of circulating hepatitis A virus (HAV) associated with cases of acute diarrhea among children under 5 years of age in Kumba-Cameroon. Reverse transcription PCR, sequencing, and phylogenetic analysis of a 371 bp segment of the VP1/P2A junction of six isolates obtained from stool samples showed the exclusive emergence of genetically related HAV subgenotype IA. All the isolates clustered within a unique lineage exhibiting a 99.5% nucleotide identity suggesting infection from a common source. The Cameroonian HAV isolates did not intermix or cluster with those from other regions of Africa and the rest of the world. Tajima's neutralization tests using the six sequences suggested HAV/IA population expansion (D = -1.37; P = 0.016). This is the first description of indigenous HAV genotypes circulating in Cameroon revealing a community-wide spread and predominance of HAV/1A infection in the Kumba area. These findings stress the need for routine molecular tracking of HAV infection as a contributory cause of acute diarrhea in Cameroonian children.

Absence of routine molecular testing and prevalence of HIV-2 infection in regions hardest-hit by HIV infection.

INTRODUCTION: Investigating the incidence and dynamics of HIV-2 and false-negative HIV test results in a highly sexually active population where frequent opportunities exist for acquiring and transmitting infections provides additional understanding of the epidemiology of the virus in Africa. METHODOLOGY: The HIV status of 900 active female sex workers (FSWs) was determined using two lateral flow rapid assays in series. The second rapid test device incorporates type-specific recombinant peptides that discriminate between HIV-1 and HIV-2 infection. HIV sero-negative samples were re-tested for HIV infection and their viral loads determined using the NucliSENS real-time nucleic acid sequence-based amplification (NASBA) platform. RESULTS: In total, 335 FSWs were determined to be HIV positive, the majority (227; 67.8%) of whom were between the ages of 20 and 30 years. Eighteen (5.4%) were found to have evidence of HIV-2 infection, 17 of whom were co-infected with HIV-1. Only one HIV-2 mono-infection was observed. Out of 565 HIV-negative individuals determined by serology, 11(1.9%; p > 0.05) were found to be HIV-1 positive when tested via the NASBA platform. CONCLUSION: False negative test results, HIV-2 infection, and complex transmission networks among FSWs may aid in fueling the HIV epidemic in the Nigerian population. These findings demonstrate the need to reevaluate the quality of HIV serological diagnostics, control services, and stress the need for widespread introduction of molecular testing among high-risk populations in the country.

Prevalence of hepatitis B e antigen in chronic HBV carriers in North-central Nigeria.

Hepatitis B virus (HBV) is an important clinical problem due to its worldwide distribution and potential of adverse sequelae, including hepatocellular carcinoma (HCC). We studied the prevalence of hepatitis B virus e antigen (HBeAg) among individuals determined to be HBV surface antigen-positive (HBsAg+) and analyzed the gender/age category associated with more active HBV infection. A total of 572 HBsAg+ individuals, as determined by a double antibody sandwich ELISA method, participated in the study. They were tested for HbeAg, using a lateral flow chromatographic immunoassay. One hundred and ten individuals were found to be HBeAg-positive giving an overall prevalence of 19.2%. Of these 110 individuals, 20 (18.2%) were females, and 90 (81.8%) were males. Thus, the prevalence of HBeAg appears to be higher in males than in females (p < 0.05). Our data also revealed that the prevalence of HBeAg was higher in patients between the age-group of 0-10 years and 11-20 years and appeared to decrease with increase in age. Taken together, our data show that approximately 1/5 of HBV-infected individuals are HBeAg+, suggesting that the virus is actively replicating and infecting liver-cells thereby ensuring an HBV-transmission pool within the Nigerian population. We suggest strengthening of the childhood HBV vaccination programmes, massive intervention activities, and treatment programmes, especially among young people to reverse the possible devastating effect of HBV infection. The success of these efforts will depend on our resolution to make the elimination of HBV infection a top priority on the public-health agenda as we start the second decade of this new century.

Antimicrobial potentials of silver colloidal (nanorods) on clinical isolates in Bayelsa state, Nigeria.

Antimicrobial resistance in developing countries has long been an issue of major concern. Nanotechnology has become an eye opener for the intervention on multiple drug resistance organisms. In this study we investigated the antimicrobial potentials of Silver Nitrate (nanorods) solution used in managing infectious diseases, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the product against microbial isolates were determined using standard microbiological techniques. The mean MIC and MBC of silver nitrate solution on fungi (0.16 µg/ml and 0.29 µg/ml respectively) was significantly lower than that of Gram positive organisms (2.35µg/ml and 2.62µg/ml) and Gram negative organisms (2.05 µg/ml and 2.10 µg/ml). Of all the Gram positive organisms, Staphylococcus spp recorded the lowest mean MIC and MBC while in the Gram negative organisms group, E. coli isolates showed the lowest mean MIC and MBC of the silver nitrate solution, though not significantly different from the other isolates. In conclusion, results from this study revealed that Silver Nitrate(nanorods) may have be broad spectrum in activity, but with higher antifungal potentials.

CD4+ T lymphocyte reference values of immunocompetent subjects in an African university.

CD4(+) T cells play critical roles in the immune system and, being primary targets of HIV infection, they are used to measure disease progression and response to combination antiretroviral therapy (cART), alongside other parameters, in HIV/AIDS patients. The aim of this study was to determine the reference values of CD4(+) T cells in a student population that was HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) negative. After ethical clearance and informed consent, 500 subjects (mean age = 26 years) were recruited, of whom 56 (11.2%) had HIV, HBV or HCV and were excluded. Blood samples were collected from the remaining 444 subjects into vacutainer tubes and analysed using the BD FACScount cytometer according to the manufacturer's instructions. Of the 444 subjects, 266 (59.9%) were male and 178 (40.1%) were female. The mean (± standard deviation) CD4(+) T cell count was 987 cells/µL (± 336). The mean counts among males and females were 957 cells/µL (± 306) and 991 cells/µL (± 340), respectively. Values of CD4(+) T cells ranged from 651 cells/µL to 1705 cells/µL. Subjects with higher CD4(+) T Cells were more likely to be female than male. There was no direct correlation between CD4(+) T cell values and age of the participants. Our findings offer the first insight into the CD4(+) T cell reference values of a Nigerian student population and provide useful data that will guide future cART decisions and other immune-based therapies.

Estimates of human immunodeficiency virus incidence among female sex workers in north central Nigeria: implications for HIV clinical trials.

We estimated the HIV incidence among commercial female sex workers (FSWs) in north central Nigeria using bimodal methodology. Using a cross-sectional study design, a total of 900 active FSWs between the ages of 18 and 35 years were recruited from 52 brothels within Nasarawa State, Nigeria. A rapid test algorithm was used to determine their HIV status. The BED IgG-Capture enzyme immunoassay (CEIA) was applied on the HIV-seropositive samples to detect recent HIV-1 infection for the estimation of incidence among those with HIV infection. Of the 900 FSWs tested, 335 (37.2%) were found to be positive for HIV. Of these, 63 showed evidence of recent infection. Using two third-generation BED analysis approaches that account for false-recent rate, an annualized adjusted HIV incidence of 11.97% (95% CI: 8.51-15.43%) and 12.36% (95% CI: 8.18-16.34%) was observed; difference P>0.05. In addition, 875 (97.2%) of the FSWs readily agreed to participate in HIV clinical trials. We have developed the expertise and infrastructure necessary for clinical trial investigations in sub-Saharan Africa. We have recorded a high proportion of recent HIV infections among FSWs in Nigeria and also provided an enabling environment for future studies of HIV prevention methods.

Broad antibody mediated cross-neutralization and preclinical immunogenicity of new codon-optimized HIV-1 clade CRF02_AG and G primary isolates.

Creation of an effective vaccine for HIV has been an elusive goal of the scientific community for almost 30 years. Neutralizing antibodies are assumed to be pivotal to the success of a prophylactic vaccine but previous attempts to make an immunogen capable of generating neutralizing antibodies to primary "street strain" isolates have resulted in responses of very limited breadth and potency. The objective of the study was to determine the breadth and strength of neutralizing antibodies against autologous and heterologous primary isolates in a cohort of HIV-1 infected Nigerians and to characterize envelopes from subjects with particularly broad or strong immune responses for possible use as vaccine candidates in regions predominated by HIV-1 CRF02_AG and G subtypes. Envelope vectors from a panel of primary Nigerian isolates were constructed and tested with plasma/sera from the same cohort using the PhenoSense HIV neutralizing antibody assay (Monogram Biosciences Inc, USA) to assess the breadth and potency of neutralizing antibodies. The immediate goal of this study was realized by the recognition of three broadly cross-neutralizing sera: (NG2-clade CRF02_AG, NG3-clade CRF02_AG and NG9- clade G). Based on these findings, envelope gp140 sequences from NG2 and NG9, complemented with a gag sequence (Clade G) and consensus tat (CRF02_AG and G) antigens have been codon-optimized, synthesized, cloned and evaluated in BALB/c mice. The intramuscular administration of these plasmid DNA constructs, followed by two booster DNA immunizations, induced substantial specific humoral response against all constructs and strong cellular responses against the gag and tat constructs. These preclinical findings provide a framework for the design of candidate vaccine for use in regions where the HIV-1 epidemic is driven by clades CRF02_AG and G.

Estimating the time period between infection and diagnosis based on CD4+ counts at first diagnosis among HIV-1 antiretroviral naïve patients in Nigeria.

INTRODUCTION: CD4+ T-cell levels are an important criterion for categorizing HIV-related clinical conditions. Late diagnosis of infection contributes to poor medical outcomes and the continuation of viral transmission. This population-based cohort study in north central Nigeria reports the initial CD4+ lymphocyte counts at the time of first HIV diagnosis and determines the approximate time interval when HIV infection was acquired. METHODOLOGY: Confirmed HIV-1 infected individuals (n = 588) for whom the dates of first HIV diagnosis were known were enrolled in this study. CD4+ lymphocyte counts were measured using a Fluorescence Activated Cell Sorter (FACS) platform that automatically quantifies CD4+ lymphocytes as absolute numbers of lymphocytes per µL of blood. The estimated time interval between HIV infection and time of first HIV diagnosis was determined as a function of the CD4+ lymphocytes' decay rate per calendar year. RESULTS: The results showed that 22.1% and 49.7% of HIV-infected individuals present late with advanced (CD4+: 200-349 cells/mL) and severe (CD4+: < 200 cells/mL) immunosuppression respectively, while only 12.1% present with CD4+ ≥ 500 cells/mL and 16.2%with CD4+ between 350-499 cells/mL. Mean CD4+ counts for females were higher when compared to those of males (p > 0.05), The time interval between HIV infection and first diagnosis was approximately 6.1 years for males and 7.3 years for females. CONCLUSION: The majority of HIV-infected individuals in this study accessed health care at late stages of infection, suggesting many HIV-infected individuals in Nigeria are unaware of their HIV status. More efficient programs for early diagnosis of HIV to prevent transmission are urgently required.

Hepatitis B virus infections in apparently healthy urban Nigerians: data from pre-vaccination tests.

BACKGROUND: In spite of the availability of an effective vaccine since 1982 against hepatitis B, infection with hepatitis B virus (HBV), which is 50 to 100 times more infectious than HIV, still persists in most parts of the world with Nigeria being described as an endemic zone. We therefore set out to establish the prevalence of this infection and evaluate its relationship with age and gender in urban Nigerians. METHODOLOGY: During pre-vaccination tests, blood samples were collected by finger-prick and venepuncture from 1,891 subjects aged < or = 60 years, between 2008 and 2009 after having obtained informed consent and ethical clearance. Smart Check HBsAg (Globalemed, Cape Town, South Africa) and ShantestTM-HBsAg Elisa (Shantha Biotechnics Ltd, Hyderabad, India) were used for initial and confirmatory tests respectively. RESULTS: Of the 1,891 participants, 957 (50.6 %) were males and 934 (49.4%) were females. Overall 114 (6.0%) were positive, of whom 71 (7.4%) were males and 43 (4.6%) females. Those aged 21-30 years had the highest infection rate, and males were more likely to be infected with the virus than females (P > 0.05). CONCLUSIONS: Such a high prevalence of a vaccine-preventable infection questions the effectiveness of the Nigerian vaccination strategies. The Nigerian government hepatitis B vaccination programme, which hitherto is limited to the National Childhood Immunisation Programme, should include the adult population.

Urban-rural estimation of hepatitis C virus infection sero-prevalence in north Central Nigeria.

BACKGROUND/OBJECTIVE: The epidemiology of hepatitis C virus (HCV) infection has been partially described for at risk groups in urban communities in Nigeria. On the other hand, literature on the possible spread of the virus in rural Nigeria remains extremely scanty. The objective of this study was to estimate the prevalence of HCV in a rural and urban community in Nigeria. METHODS: Four hundred and twenty four (n = 424) plasma samples belonging to 238 rural inhabitants and 186 urban dwellers in North Central Nigeria were tested for anti-HCV markers using a third generation quantitative enzyme-linked immunosorbent assay (ELISA) that uses recombinant proteins and synthetic peptides derived from core and non-structural regions. RESULTS: 29(12.2%, CI = 0.17-0.86) of the rural samples and 5(2.7%, CI = 0.01-0.06) of urban samples were positive for HCV infection. The highest number of infections was in the 21-40 years age category. Our preliminary findings indicates that the number of HCV infection in rural was higher (p = 0.03) when compared with urban settings in Nigeria. CONCLUSION: Our results suggest a higher prevalence of HCV infection in rural than urban Nigeria in the region studied and possibly in Nigeria as a whole. HCV transmission is active in rural Nigeria and large scale studies to understand the dynamics of the infection are required so as to plan targeted preventive measures.

Preliminary Report on HIV-1 Vaccine Preparedness in Nigeria: Advantages of Recruiting University Students.

The national HIV seroprevalence in Nigeria has risen steeply from about 3% in 1993 to 5-8% in 2001 and now stands at 4.4%. HIV epidemic continues to be a serious threat to the most populous country in Africa with a population of 140 million, with limited use of antiviral drugs that is taken for life since it only suppresses the virus without completely eliminating the virus or leading to cure. Only a change in social behavior and an affordable vaccine can halt the epidemic in Africa. We report here results of a pilot study on the recruitment strategies, sociodemographic aspects and HIV risk behavior of a cohort of normal volunteers recruited at the University of Jos, Nigeria. Our study recorded a high degree of interest and zeal to participate in HIV vaccine studies by volunteers, and demonstrated the superiority of snowballing over invitation by mail, as a recruitment strategy. A cohort of university students may be particularly suitable for conducting HIV vaccine trials because of the assurance of prospective follow-up for up to four years (time to graduation), and a good understanding of the risks and benefits of participation as outlined in the informed consent. We had 100% retention during a follow-up period of two years. Most importantly, the cohort reflected a relatively low HIV seroprevalence, which gives preventive programs the potential to blunt or halt the epidemic.

Evaluation of a recombinant DNA hepatitis B vaccine in a vaccinated Nigerian population.

INTRODUCTION: Recombinant hepatitis B vaccine was introduced in 1986 and has gradually replaced the plasma-derived hepatitis B vaccine. No published data are available on the immunogenicity of hepatitis B vaccines in Nigerians. The current study aimed to evaluate protective sero-conversion rates after vaccination with Shanvac-B rDNA hepatitis B vaccine in Nigerian subjects between January and September 2009. METHODOLOGY:   After having obtained informed consent and ethical clearance, 2 mL of blood were aseptically collected from each participant aged ≤50 years, one month after the first, second and third doses of the vaccine. Sera were separated into cryovials and frozen at -21oC until analysed for the detection of the protective antibody titre induction. Protective antibody titre was defined as a titre of ≥10 mIU/mL. RESULTS: Of the 376 participants, 192 (51.1%) were males and 184 (48.9%) were females. A total of 144 subjects participated in the first-dose group, nine (6.3%) of whom developed protective antibody titre (8.3% of males and 4.2% of females). Of the 121 participants in the second-dose group, 108 (89.3%) developed protective antibody titre (98.3% of males and 80.3% of females), while of the 111 participants in the third-dose group, 100% protectively sero-converted. Males were more likely to develop protective antibody titre than females after the second dose (P < 0.05). CONCLUSION: This data provides additional evidence for the efficacy of Shanvac-B rDNA hepatitis B vaccine and the need to adhere to the recommended three-dose schedule to achieve full and lasting sero-protection among Nigerians.

Serological markers and risk factors for hepatitis B and hepatitis C viruses among students in a Nigerian university.

OBJECTIVE: The aim of this cross-sectional study was to estimate the seroprevalence rates of hepatitis B virus and hepatitis C virus infections and to analyze associated risk factors among 400 students in a Nigerian. METHODS: Participants were interviewed in a face-to-face sessions through a short structured questionnaire. Qualitative rapid immuno-chromatography test were used to screen for HBsAg and anti-HCV antibodies and these were confirmed by using third generation quantitative enzyme-linked immunosorbent assay (ELISAs). RESULTS: Seroprevalence rates were: HBV. All these individuals were asymptomatic and unaware of their hepatitis status prior to this study. We did not detect any case of HBV/HCV co-infection. The risk of being infected with HBV or HCV was not associated with marital status or having facial/tribal (p>0.05). A significant association was found between HCV (not HBV) infection and blood transfusion {OR=5.0 (95% CI=0.91-27.47); chi2=4.15; p=0.04}. CONCLUSION: Although the seroprevalence of HBV and HCV is lower among university students when compared to blood donors, HIV/AIDS patients and health workers in Nigeria. We have shown that these viruses circulate among the study population and blood transfusion identified as the factors most associated with HCV infection. Routine donor screening needs to be enforced and it is essential to implement prevention strategies focused on university students and youths in general.

Human immunonodeficiency virus, hepatitis B virus and hepatitis C virus: sero-prevalence, co-infection and risk factors among prison inmates in Nasarawa State, Nigeria.

BACKGROUND: Published data on HIV, HBV, and HCV in correctional facilities in Nigeria is scarce. We set out to establish the seroprevalence, co-infection, and risk factors for these infections for the first time among prison inmates in Nasarawa State, Nigeria. METHODOLOGY: In a cross-sectional study conducted between April and May, 2007, blood samples were collected from 300 male prisoners of a mean age of 29.2 years, in the state's four medium-security prisons (overall population: 587). Prior to the study, ethical clearance and informed consent were obtained and structured questionnaires were administered. Samples were analyzed for HIV, HBsAg, and HCV using anti-HIV 1+2-EIA-avicenna, Shantest-HBsAg ELISA, and anti-HCV-EIA-avicenna, respectively. Specimens initially reactive for HIV were retested with vironostika microelisa. Data were analyzed using SPSS version 13.0. P values < or = 0.05 were considered significant. RESULTS: Of the 300 subjects, 54 (18.0 %), 69 (23.0 %), and 37 (12.3 %) tested positive for HIV, HBV, and HCV, respectively. Co-infections were eight (2.7 %) for HIV/HBV and two (0.7 %) for HBV/HCV. Those aged 21-26 years were more likely to be infected with HIV and HBV, while those aged 33-38 years had the highest HCV infection. Associated risk factors included duration in prison, previous incarceration (for HIV, HBV and HCV), intra-prison anal sex, multiple sex partners (for HIV and HBV), ignorance of transmission modes, blood transfusion, and alcohol consumption (for HBV and HCV). No inmate injected drugs. CONCLUSIONS: The overall outcome represents the need for prison-focused intervention initiatives in Nigeria. Injected drug use is an unlikely major transmission mode among Nigerian inmates.