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    Evans Obboh

    <p>Liver function results of 49 pregnant women who were positive for HEV IgG and/or IgM.</p
    Questionnaire. (DOCX 41Â kb)
    Background. HIV infection is marked by the production of cytokines by infected cells and cells of the immune system. Variations in the levels of cytokine in HIV-infected individuals significantly impact the role of the immune system with... more
    Background. HIV infection is marked by the production of cytokines by infected cells and cells of the immune system. Variations in the levels of cytokine in HIV-infected individuals significantly impact the role of the immune system with the possibility to affect the course of HIV disease by either exacerbating or suppressing HIV replication. Aim. The study sought to investigate the effect of sociodemographic indices, clinical laboratory parameters, and ART regimen on Th1, Th2, and Th17 cytokines in HIV patients. Materials and methods. A total of two hundred (200) HIV patients on either the first or second line of ART were recruited into the study. Sociodemographic indices were collected using researcher-administered questionnaires. Serum concentrations of two major immune-promoting cytokines, IL-12 and IFN-γ, and immune-suppressive cytokines, IL-10 and IL-17, were measured using enzyme-linked immunosorbent assay (ELISA). T-test and chi-square were used to compare mean scores, while...
    Additional file 4: Figure S1. Antigenic polymorphisms.
    A clear understanding of the properties of naturally induced antibody responses against transmission-blocking vaccine candidates can accelerate the understanding of the development of transmission-blocking immunity. This study... more
    A clear understanding of the properties of naturally induced antibody responses against transmission-blocking vaccine candidates can accelerate the understanding of the development of transmission-blocking immunity. This study characterized the naturally induced IgG responses against two leading transmission-blocking vaccine antigens, Pfs230 and Pfs48/45, in non-febrile children living in Simiw, Ghana. Consecutive sampling was used to recruit 84 non-febrile children aged from 6 to 12 years old into the 6-month (November 2017 until May 2018) longitudinal study. Venous blood (1 ml) was collected once every 2 months and used to determine hemoglobin levels, P. falciparum prevalence using microscopy and polymerase chain reaction, and the levels and relative avidity of IgG responses against Pfs230 and Pfs48/45 using indirect ELISA. IgG levels against Pfs230 and Pfs48/45 decreased from the start (November) to the middle (January) and end (March) of the dry season respectively, then they be...
    Background Indicators of successful malaria control interventions include a reduction in the prevalence and densities of malaria parasites contained in both symptomatic and asymptomatic infections as well as a reduction in malaria... more
    Background Indicators of successful malaria control interventions include a reduction in the prevalence and densities of malaria parasites contained in both symptomatic and asymptomatic infections as well as a reduction in malaria transmission. Individuals harboring malaria parasites in asymptomatic infections serve as reservoirs for malaria transmission. This study determined the prevalence of asymptomatic malaria parasite carriage in afebrile children attending six different schools in two districts, the Cape Coast Metropolitan Assembly (CCMA) and the Komenda Edina Eguafo Abirem (KEEA) of the Central Region of Ghana. Methods This cross sectional study recruited afebrile children aged between 3 and 15 years old from six randomly selected schools in the Central Region of Ghana. Finger-pricked blood was collected and used to prepare thick and thin blood smears as well as spot a strip of filter paper (Whatman #3). Nested PCR was used to identify Plasmodium falciparum, Plasmodium malar...
    Background The Alere™ Malaria Ag P.f Ultra-sensitive RDT (UsmRDT) kit is an HRP2-based malaria rapid diagnostic test (RDT) with enhanced sensitivity relative to the SD Bioline Malaria Ag P.f RDT (mRDT) kit. However, the diagnostic... more
    Background The Alere™ Malaria Ag P.f Ultra-sensitive RDT (UsmRDT) kit is an HRP2-based malaria rapid diagnostic test (RDT) with enhanced sensitivity relative to the SD Bioline Malaria Ag P.f RDT (mRDT) kit. However, the diagnostic performance of the UsmRDT kit has not been evaluated in Ghana. Methods A total of 740 afebrile participants aged between 3 and 88 years old were recruited from the Central and Greater Accra Regions of Ghana during the off-peak malaria season. Axillary body temperature was measured, and a volume of 1 ml venous blood was drawn from each participant. Prior to separating the blood into plasma and packed cell pellets via centrifugation, the blood was spotted onto one UsmRDT and one mRDT kit and also used to prepare thick and thin blood smears as well as filter paper blood spots. Plasmodium falciparum specific polymerase chain reaction (PCR) was performed on gDNA extracted from 100 µl of the whole blood. Results The overall positivity rate for microscopy, PCR, U...
    Subclinical infections that serve as reservoir populations to drive transmission remain a hurdle to malaria control. Data on infection dynamics in a geographical area is required to strategically design and implement malaria... more
    Subclinical infections that serve as reservoir populations to drive transmission remain a hurdle to malaria control. Data on infection dynamics in a geographical area is required to strategically design and implement malaria interventions. In a longitudinal cohort, we monitored Plasmodium falciparum infection prevalence and persistence, and anti-parasite immunity to gametocyte and asexual antigens for 10 weeks. Of the 100 participants, only 11 were never infected, whilst 16 had persistent infections detected by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR), and one participant had microscopic parasites at all visits. Over 70% of the participants were infected three or more times, and submicroscopic gametocyte prevalence was high, ≥ 48% of the parasite carriers. Naturally induced responses against recombinant Pfs48/45.6C, Pfs230proC, and EBA175RIII–V antigens were not associated with either infection status or gametocyte carriage, but the antigen-specific IgG...
    Additional file 3: Table S3. Seroreactivity of sera from individuals infected with mutant parasites.
    Malaria is spread by the transmission of sexual stage parasites, called gametocytes. However, with Plasmodium falciparum, gametocytes can only be detected in peripheral blood when they are mature and transmissible to a mosquito, which... more
    Malaria is spread by the transmission of sexual stage parasites, called gametocytes. However, with Plasmodium falciparum, gametocytes can only be detected in peripheral blood when they are mature and transmissible to a mosquito, which complicates control efforts. Here, we identify the set of genes overexpressed in patient blood samples with high levels of gametocyte-committed ring stage parasites. Expression of all 18 genes is regulated by transcription factor AP2-G, which is required for gametocytogenesis. We select three genes, not expressed in mature gametocytes, to develop as biomarkers. All three biomarkers we validate in vitro using 6 different parasite lines and develop an algorithm that predicts gametocyte production in ex vivo samples and volunteer infection studies. The biomarkers are also sensitive enough to monitor gametocyte production in asymptomatic P. falciparum carriers allowing early detection and treatment of infectious reservoirs, as well as the in vivo analysis ...
    Background. HIV infection is marked by the production of cytokines by infected cells and cells of the immune system. Variations in the levels of cytokine in HIV-infected individuals significantly impact the role of the immune system with... more
    Background. HIV infection is marked by the production of cytokines by infected cells and cells of the immune system. Variations in the levels of cytokine in HIV-infected individuals significantly impact the role of the immune system with the possibility to affect the course of HIV disease by either exacerbating or suppressing HIV replication. Aim. The study sought to investigate the effect of sociodemographic indices, clinical laboratory parameters, and ART regimen on Th1, Th2, and Th17 cytokines in HIV patients. Materials and methods. A total of two hundred (200) HIV patients on either the first or second line of ART were recruited into the study. Sociodemographic indices were collected using researcher-administered questionnaires. Serum concentrations of two major immune-promoting cytokines, IL-12 and IFN-γ, and immune-suppressive cytokines, IL-10 and IL-17, were measured using enzyme-linked immunosorbent assay (ELISA). T-test and chi-square were used to compare mean scores, while...
    Background The ABO and the Rhesus blood group systems, as well as various abnormal haemoglobin (Hb) variants (haemoglobinopathies) are known to influence malaria parasite carriage and disease severity in individuals living in malaria... more
    Background The ABO and the Rhesus blood group systems, as well as various abnormal haemoglobin (Hb) variants (haemoglobinopathies) are known to influence malaria parasite carriage and disease severity in individuals living in malaria endemic areas. This study identified the blood group and Hb variant distribution and Plasmodium falciparum infection status of afebrile individuals living in southern Ghana. Methods Afebrile participants were recruited from Obom (358) in the Greater Accra Region and Ewim (100) and Simiw (329) in the Central Region of Ghana. Venous blood (1 ml) was collected into EDTA vacutainer tubes. Three 20 μl drops of blood were used for blood group analysis using the tile method. Another 500 μl aliquot was used for the qualitative sickling test using sodium metabisulphite and haemoglobin electrophoresis. Genomic DNA was extracted from 100 μl of whole blood and used in P. falciparum species-specific PCR. Results The most abundant blood group and abnormal haemoglobin...
    Background Hepatitis E virus is an emerging infection in Africa with poor maternal and foetal outcomes. There is scanty data on the sero-prevalence of HEV infection among pregnant women in Ghana. This study highlighted the prevalence and... more
    Background
    Hepatitis E virus is an emerging infection in Africa with poor maternal and foetal outcomes. There is scanty data on the sero-prevalence of HEV infection among pregnant women in Ghana. This study highlighted the prevalence and risk factors associated with HEV infection among pregnant women in Cape Coast Metropolis, Central Region of Ghana.
    Methods
    A multicenter (3 selected sites) analytical cross sectional study involving 398 pregnant women in the Cape Coast metropolis was conducted. HEV (Anti-HEV IgG and Anti-HEV IgM) ELISA was performed. Sero-positive women had liver chemistries done and data collected on maternal and neonatal outcomes. Data analyses were performed using Stata version 13 software (STATA Corp, Texas USA).
    Results
    Mean age was 28.01 (± 5.93) years. HEV sero-prevalence was 12.2% (n = 48) for IgG and 0.2% (n = 1) for IgM with overall of 12.3%. The odds of being HEV sero-positive for women aged 26±35 years was 3.1 (95% CI: 1.1±8.1), p = 0.02 and 36 years it was 10.7 (95% CI; 3.4±33.5), p = 0.0001. Living in urban settlement was associated with lowest odds of HEV infection {OR 0.4 (95% CI; 0.2±0.8), p = 0.01}. Factors with no statistical evidence of association include main source of drinking water and history of blood transfusion. The sero-prevalence of HEV IgG increased progressively across trimesters with the highest among women in their third trimester (55.3%). None of the 49 HEV sero-positive women had elevated ALT level. Ten (N = 41) of the neonates born to sero-positive women developed jaundice in the neonatal period. The mean birth weight was 3.1kg (SD 0.4).
    Conclusion
    HEV sero-prevalence among pregnant women in the Cape Coast Metropolis is high enough to deserve more attention than it has received so far. It is therefore important to conduct further research on the potential impact on maternal and neonatal mortality and morbidity in
    Ghana.
    Research Interests: