Georgina N. Odaibo

Respiratory syncytial virus infection: denominator-based studies in Indonesia, Mozambique, Nigeria and South Africa

OBJECTIVE To assess the burden of respiratory syncytial virus (RSV)-associated lower respiratory infections (LRI) in children in four developing countries. METHODS A WHO protocol for prospective population-based surveillance of acute respiratory infections in children aged less than 5 years was used at sites in Indonesia, Mozambique, Nigeria and South Africa. RSV antigen was identified by enzyme-linked immunosorbent assay performed on nasopharyngeal specimens from children meeting clinical case definitions. FINDINGS Among children aged < 5 years, the incidence of RSV-associated LRI per 1000 child-years was 34 in Indonesia and 94 in Nigeria. The incidence of RSV-associated severe LRI per 1000 child-years was 5 in Mozambique, 10 in Indonesia, and 9 in South Africa. At all study sites, the majority of RSV cases occurred in infants. CONCLUSION These studies demonstrate that RSV contributes to a substantial but quite variable burden of LRI in children aged < 5 years in four developing countries. The possible explanations for this variation include social factors, such as family size and patterns of seeking health care; the proportion of children infected by human immunodeficiency syndrome (HIV); and differences in clinical definitions used for obtaining samples. The age distribution of cases indicates the need for an RSV vaccine that can protect children early in life.

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.

Complete Genome Sequence of a Genotype XVII Newcastle Disease Virus, Isolated from an Apparently Healthy Domestic Duck in Nigeria

ABSTRACT The first complete genome sequence of a strain of Newcastle disease virus (NDV) of genotype XVII is described here. A velogenic strain (duck/Nigeria/903/KUDU-113/1992) was isolated from an apparently healthy free-roaming domestic duck sampled in Kuru, Nigeria, in 1992. Phylogenetic analysis of the fusion protein gene and complete genome classified the isolate as a member of NDV class II, genotype XVII.

A new affordable flow cytometry based method to measure HIV‐1 viral load

Most commercially available assays for diagnosis of HIV infection have shown shortcomings in the detection and quantification of rare genotypes of the virus. Most of the assays do not detect subtype O (outlier) and/or N (nonmajor, nonoutlier) or new circulating recombinant forms (CRFs), which are becoming more important in sub‐Saharan Africa. Furthermore, the commonly available tests require costly measuring devices and expensive test kits, which are not easily affordable for developing countries. This study was designed to explore solutions to the problem of viral load assays in developing countries. Two forward primers, digoxygenin (DIG) and dinitrophenol (DNP) labeled, and one biotin (BIO) labeled reverse primer were used to amplify both, the HIV‐1‐5′LTR (long terminal repeat) region and an internal standard sequence. The two polymerase chain reaction (PCR)‐products were captured by anti‐DIG and anti‐DNP antibody coated microparticles. Flow cytometric analyses were carried out after labeling with streptavidin‐R‐phycoerythrine. The primer system used recognized all HIV‐1 subtypes. A coamplified internal standard warranted the functionality of the PCR and allows reproducible viral load measurements. Two drawbacks of current viral load measurements are overcome by the flow cytometry based test described hereof. First, all known worldwide relevant HIV‐1 subtypes including subtypes O, N, and new CRFs are quantifiable with high sensitivity (50 to >1 × 106 copies per PCR). Second, the cost per test can be reduced to less than 12 US

An improved PCR method for detection of HIV-1 proviral DNA of a wide range of subtypes and recombinant forms circulating globally.

instead of the current 50–100 US

Clinical and Immunological Profile of Pediatric HIV Infection in Ibadan, Nigeria.

. Additionally, the test described in this report offers the possibility to perform complete monitoring program (CD4 T‐cell count, CD4% and viral load) for the first time, with the same device for HIV‐infected persons.

Dyslipidemia in ART-Naive HIV-Infected Persons in Nigeria--Implications for Care.

Proviral DNAs are being measured increasingly as a marker of the efficacy of highly active anti-retroviral therapy (HAART) and is accepted for the early diagnosis of perinatal HIV-1 infections. This requires a standardized test which enables the detection of a wide range of subtypes worldwide including O, N and circulating recombinant forms (CRFs). Based on a previous publication, a PCR - Test for HIV-1 provirus detection in peripheral blood mononuclear cells (PBMCs) was developed. Blood samples from 80 individuals infected with HIV-1 and 20 persons negative for HIV-1&2 from Africa and Germany were tested for the presence of HIV-1 provirus DNA. The primer system used enables the detection of proviral DNA despite the high concentrations of human DNA. The limit of detection was determined to be 5 copies per 10(5) cells. All 20 samples from persons negative for HIV were negative for HIV-1 proviral DNA while provirus DNA was amplified from 76 of the 80 (95%) samples from persons infected with HIV. The amplified products were detected by gel-electrophoresis, flow cytometry and real-time PCR. All three detection systems provided the same results.

Circulation of the low pathogenic avian influenza subtype H5N2 virus in ducks at a live bird market in Ibadan, Nigeria

In spite of the increasing number of children living with HIV in Nigeria, published data on their clinical profile are few. We describe the clinical profile at presentation of HIV-infected children at the University College Hospital, Ibadan, in a prospective study. Among 272 children studied (149 [54.8%] males; mean age 4.2 years [range 2 months to 15 years]), infection was acquired through vertical transmission in 252 (92.6%), blood transfusion in 5 (1.80%), and undetermined routes in 15 (5.5%) cases. Clinical features included weight loss (62.5%), prolonged fever (55.4%), generalized lymphadenopathy (48.6%), chronic cough (45.4%), and persistent diarrhea (28.3%). Tuberculosis was present in 45.3%, World Health Organization (WHO) clinical stages 3 and 4 disease in 70.6% and severe immunosuppression in 44.5% of cases. Pediatric HIV in Ibadan is acquired mainly vertically and most cases present with severe disease. Improved access to prevention services and early diagnosis are recommended.

Risk of hepatitis B virus in the slaughter house

Aims: This study aimed to describe the prevalence and pattern of lipid abnormalities among antiretroviral therapy (ART)-naive HIV patients, understand if there is any relationship to virologic and immunologic status, and discuss the implications for care. Methods: This was a cross-sectional study in which baseline demographic, clinical, and laboratory data of all ART-naive HIV-infected individuals recruited into the adult ARV clinic, University College Hospital, Ibadan, between January and December 2006, were analyzed. Results: In total, 1316 ART-naive HIV-infected persons were recruited in the period. Females subjects and participants aged ≦35 years accounted for 67.1% and 57.7% of all participants, respectively. At least 1 abnormal lipid fraction was seen in 73.3% of participants. It was observed that in 11.5% participants the total cholesterol (TC) was ≧5.2 mmol/L, in 2.7% the low-density lipoprotein cholesterol (LDL)-C was >4.1 mmol/L in 56.5% the high-density lipoprotein cholesterol (HDL)-C was <1.0 mmol/L, and in 27.6% the triglyceride (TG) was >1.7 mmol/L. The TC, LDL-C, and HDL-C were all significantly positively correlated with CD4 counts and negatively correlated with viral load. On the contrary, the TG levels were negatively correlated with CD4 counts and positively correlated with viral load. Multivariate linear analysis showed a significant relationship between all the lipid parameters and viral load. CD4 counts were only significantly associated with TC. Conclusions: A significant burden of dyslipidemia exists among ART-naive HIV-infected persons. Low HDL-C was the most frequently observed abnormality. The abnormalities related more with viral load levels than with CD4 counts. Dyslipidemia screening should be done in ART-naive HIV-infected persons. Simple healthy lifestyle changes should be emphasized, with other care given to those with the disorder.

Comparison of auditory brainstem response in HIV-1 exposed and unexposed newborns and correlation with the maternal viral load and CD4+ cell counts.

BackgroundTo monitor carrier hosts of avian influenza in Nigeria, we randomly collected cloaca swab specimens from 155 ducks at a live bird market (LBM) in Ibadan, southwest Nigeria, between July 2011 and July 2012.MethodsThe samples were analyzed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and virus isolation was carried out in embryonated chicken eggs. Partial sequencing of the antigenic cleavage site of the haemagglutinin (HA) gene was performed, multiple sequence alignment was carried out using ClustalW, and a phylogenetic tree was constructed using the neighbor joining method.ResultsTwenty (13%) of the 155 samples were positive for avian influenza subtype H5N2 by real-time RT-PCR and three isolates were obtained from embryonated chicken eggs. Partial sequencing of the amino acid cleavage site of the HA genes of two isolates corresponded to a PQRETGL*F sequence that is common in low pathogenic avian influenza (LPAI). Phylogenetically, the HA genes of the two influenza viruses are monophyletic and clustered with H5N2 viruses detected in wild ducks from Africa.ConclusionThe occurrence of LPAI in domestic ducks in Nigeria underscores the importance of continuous surveillance and monitoring of the virus (in a country that is considered to be free of avian influenza) in order to prevent the emergence of virulent strains that may spread to commercial poultry and humans.