http://adhlui.com.ui.edu.ng/jspui/handle/123456789/22 Department of Virology Sat, 28 Feb 2026 11:27:47 GMT 2026-02-28T11:27:47Z http://adhlui.com.ui.edu.ng/jspui/handle/123456789/1297 Title: High Rate of Non-detectable HIV-1 RNA Among Antiretroviral Drug Naive HIV Positive Individuals in Nigeria Authors: Odaibo, Georgina N; Adewole, Issac F; Olaleye, David O Abstract: Plasma HIV-1 RNA concentration, or viral load, is an indication of the magnitude of virus replication and largely correlates with disease progression in an infected person. It is a very useful guide for initiation of therapy and monitoring of response to antiretro viral drugs. Although the majority of patients who are not on antiretroviral therapy (ART) have a high viral load, a small proportion of ART naive patients are known to maintain low levels or even undetectable viral load levels. In this study, we determined the rate of undetectable HIV-1 RNA among ART naive HIV positive patients who presented for treatment at the University College Hospital (UCH), Ibadan, Nigeria from 2005 to 2011. Baseline viral load and CD4 lymphocyte cell counts of 14,662 HIV positive drug naive individuals were determined using the Roche Amplicor version 1.5 and Partec easy count kit, respectively. The detection limits of the viral load assay are 400 copies/mL and 750,000 copies/mL for lower and upper levels, respectively. A total of 1,399 of the 14,662 (9.5%) HIV-1 positive drug naive individuals had undetectable viral load during the study period. In addition, the rate of non-detectable viral load increased over the years. The mean CD4 counts among HIV-1 infected individuals with detectable viral load (266 cells/µL; range = 1 to 2,699 cells/µL) was lower than in patients with undetectable viral load (557 cells/µL; range = 1 to 3,102 cells/µL). About 10% of HIV-1 infected persons in our study population had undetectable viral load using the Roche Amplicor version 1.5. Description: ARTICLE Tue, 01 Jan 2013 00:00:00 GMT http://adhlui.com.ui.edu.ng/jspui/handle/123456789/1297 2013-01-01T00:00:00Z http://adhlui.com.ui.edu.ng/jspui/handle/123456789/1295 Title: High Rate of Non-detectable HIV-1 RNA Among Antiretroviral Drug Naive HIV Positive Individuals in Nigeria Authors: Odaibo, Georgina N. Abstract: Plasma HIV-1 RNA concentration, or viral load, is an indication of the magnitude of virus replication and largely correlates with disease progression in an infected person. It is a very useful guide for initiation of therapy and monitoring of response to antiretroviral drugs. Although the majority of patients who are not on antiretroviral therapy (ART) have a high viral load, a small proportion of ART naive patients are known to maintain low levels or even undetectable viral load levels. In this study, we determined the rate of undetectable HIV-1 RNA among ART naive HIV positive patients who presented for treatment at the University College Hospital (UCH), Ibadan, Nigeria from 2005 to 2011. Baseline viral load and CD4 lymphocyte cell counts of 14,662 HIV positive drug naive individuals were determined using the Roche Amplicor version 1.5 and Partec easy count kit, respectively. The detection limits of the viral load assay are 400 copies/mL and 750,000 copies/mL for lower and upper levels, respectively. A total of 1,399 of the 14,662 (9.5%) HIV-1 positive drug naive individuals had undetectable viral load during the study period. In addition, the rate of non-detectable viral load increased over the years. The mean CD4 counts among HIV-1 infected individuals with detectable viral load (266 cells/µL; range = 1 to 2,699 cells/µL) was lower than in patients with undetectable viral load (557 cells/µL; range = 1 to 3,102 cells/µL). About 10% of HIV-1 infected persons in our study population had undetectable viral load using the Roche Amplicor version 1.5 Description: Virology: Research and Treatment 2013:4 35–40 Tue, 01 Jan 2013 00:00:00 GMT http://adhlui.com.ui.edu.ng/jspui/handle/123456789/1295 2013-01-01T00:00:00Z http://adhlui.com.ui.edu.ng/jspui/handle/123456789/702 Title: CHARACTERISATION AND SERO-EPIDEMIOLOGY OF POTISKUM VIRUS Authors: OMILABU, S. A. Abstract: Some aspects of biochemical and biophysical characteristics of Potiskum (POT) virus (a flavivirus isolated from Cricetomys gambianus) were studied in experimental animals, mosquitoes and tissue culture systems. The laboratory and domestic animals infected included Swiss albino mice, rabbits, chicks and goats. The tissue culture systems used were BHK-21, Vero, HEP-2, LLC-MK₂, E6, MA 104 MDCK, MDBK, and MEC. Aedes aegypti was the only mosquito species tested. The Nero-epidemiological pattern of the virus were also studied in both human and animal populations. POT virus passed freely through 200 and 450 nm diameter sized membrane filters. The virus titre was reduced by 2.0 logs when supsended in a diluent supplemented with serum collected from local cattle. The virus titre in tissue culture was not as high as observed in Swipe albino mice. Potiskum virus lost its infectivity to ether and chloroform. The virus lose was between 3.3 and 4.5 lost of virus particles to Ether and Chloroform respectively. POT virus also lost appreciable virus titre when suspended in glycerin buffer. The virus was also shown to be highly heat labile as more than 5.0 logs of POT virus was lost to heat (56°C) under 30 minutes. However, the virus loss at 4°C was minimal ( 2.0 logs) when stored for 120 hours. Potiskum virus haemagglutinated goose, sheep, pig and chick erythrocytes, optimally at either room, +4°C or 37°C using pH values ranging from 6.4 to 6.8; the POT haemagglutinating antigens were only detectable in sucrose-acetone extracted mouse brain materials. The enzyme-linked immunosorbent assay (ELISA) was shown to be sensitive but it could not detect POT virus antigen beyond 10⁻⁴ dilutions. The results of complement fixation and haemaglutination inhibiting antibodies assayed in either mouse or rabbit sera showed that the titres increased with POT virus dose/number of virus inocura. It was was observed that POT virus cross-reacted extensively with Uganda S, West Nile, Wesselebron and Yellow fever; antibodies to POT virus cross-reacted broadly with theme flaviviruses while their antibodies selectively reacted with POT virus. It was observed that POT virus was related to Uganda S, West Nile, Wesselsbron and Yellow fever viruses in descending order. The results of experimental infections of both laboratory and domestic animals indicated that mice, goats and chicks tested were susceptible to POT virus infection. The infection resulted in clinical disease; the animals developed viraemia of variable duration (4 - 8 days). Their susceptibility was however age and dose- dependent. The Swiss albino mice aced 2 - 15 days succumbed to IOLD₅₀ of the virus while the 7 - 15 days old chicks were refractory to infection with 1OLD₅₀ and 100LD₅₀ of POT virus. Variations in susceptibility were also observed in different routes of infection. The virus was however shown to be highly neurotropic in most of the POT virus-infected animals. High virus titres ( 6.5 logs) and marked histopathological lesions were confined to the brains of infected animals. There was 50-100% mortalities in chicks infected with 1000LD₅₀ or more of POT virus using subcutaneous (s.c.) or oral routes. The s. c. inoculated birds succumbed faster than the orally inoculated chicks. Striking pathological lesions and infective virus particles were detected in most of the organs assayed. Similarly the West African Dwarf goats showed 50% mortality when infected s.c. Their response was also dependent on age, the younger the more susceptible. The infected animals developed fever, starry hair coats, leucopaenia, nervousness, hindlimb paralysis and lateral recumbency among other signs. Infective virus particles and striking lesions were detected in the brain, lungs, liver and small intestine. Generally, complement fixing antigens were detected in the organs of infected mice and goats, however, CF antigen was not detected in the organs of POT virus infected chicks. The birds also failed to circulate CF antibodies. Potlskum virus multiplied in four of the 9 cell culture systems tested namely, BHK-21, E6, Vero and HEP-2. The virus produced cell rounding cytopathology and also formed plaques under Carboxy-methyl Cellulose (CMC) overlay medium. CF antigens were also detected in these four cell cultures. The cytological examinations of two of the susceptible cultures (BHK-21 and E6) suggested the replication of the virus both in the cytoplasm and the nucleus of these cells. The experimentally infected mosquitoes (Aedes aegypti) successfully transmitted POT virus from day 5 extrinsic incubation period (EIP). Transmission of the virus was delayed till day 10 in mosquito that received low virus dose. POT virus was circulated in the mosquitoes for 35 days when the last batch of the mosquitoes was harvested and in the suckling mice exposed to these infected mosquitoes. The sero-epidemiological studies showed that HI antibodies to flaviviruses were prevalent in both the human and animal populations tested. However the prevalence varied with different ecological zones. In humans, high POT virus activity (70%) was observed alongside yellow fever, Wesselebron, Uganda S, Dengues 1 & 2, West Nile and Banzi viruses. Few monotypic HI reaction, were found with POT virus despite its high cross-reactivity with other flaviviruses tested. The result of the plaque reduction test performed on some sera showed that 22%, of these sera reduced 50% or more of the POT virus plaques. The prevalence of flavivirus infection in animals were also moderate and POT virus activities were highest in camels, pigs and dogs as against the low response observed in goats, sheep, cattle and fowls. Generally, the prevalence observed in this study in both human and animal populations in 5 different ecological zones further accentuates the hyperendemicity of flavivirus Infections in this environments. Description: A Thesis in the Department of Virology submitted to the Faculty of Basic Medical Sciences, College of Medicine, in partial fulfillment of the requirement for the degree of Doctor of Philosophy, University of Ibadan Sun, 01 Nov 1992 00:00:00 GMT http://adhlui.com.ui.edu.ng/jspui/handle/123456789/702 1992-11-01T00:00:00Z http://adhlui.com.ui.edu.ng/jspui/handle/123456789/696 Title: GENETIC DIVERSITY AND CORECEPTOR USAGE OF HIV-1 STRAINS AMONG INFECTED INDIVIDUALS PRESENTING AT A VOLUNTARY COUNSELLING AND TESTING CENTRE IN IBADAN, NIGERIA Authors: DONBRAYE, EMMANUEL Abstract: Molecular analyses of Human Immunodeficiency Virus (HIV) have shown great genetic diversity among strains of the virus. The diversity has implications on efficiency of its transmission, pathogenesis, diagnosis, vaccine design, coreceptor usage, response to anti-retroviral therapy and development of drug resistance. The HIV epidemic in Nigeria is characterised by the presence of multiple strains of the virus and increasing resistance to some anti-retroviral drugs. This study was carried out to determine the circulating HIV-1 strains and their coreceptor usage patterns at a voluntary counseling and testing centre in Nigeria. Blood samples were collected from 85 consenting HIV-1 infected (40 seroconcondant couples and partners of 5 serodiscordant couples) anti-retroviral therapy-naive patients. They include 42 males and 43 females with median age of 37 years (range 18-58 years) who presented at a voluntary counselling and testing centre in the University College Hospital, lbadan. Genomic DNA was extracted from whole blood using a commercial DNA extraction kit. The env C2-V3 region of HIV-1 from the genomic DNA extract was amplified by nested PCR using primers WT1and WT2, and KK₄₀ and KK₃₀ for the first and second rounds, respectively. Amplified DNA was directly sequenced in both forward and reverse directions, edited and analysed for phylogenetic relationships by ClustaW and Maximum Likelihood methods in a specialized software based on their nucleotide and amino acid sequences. The target region was successfully sequenced from 64 of the 85 patterns comprising, 23 of the 40 seroconcordant couples, 13 single partners of the remaining 17 seroconcordant couples and the 5 serodiscordant couples. Overall, 3.1%, 53.1%, 28.1%, 14.1% and 1.6% of the HIV-1 env C2-V3 nucleotide sequences were identified as subtype A, G, CRFO2_AG, CRF06_cpx, and CRF35_AD, respectively, with variation in subtype distribution. Eighteen of the 23 positive seroconcordant couples were infected with the same HIV.1 strain while the other five HIV-1 seroconcordant couples were infected with different HIV-1 strains indicating independent sources of infection of each spouse .The V3 loop region of the viruses had amino acid sequence conservation in the base positions 1-8 and 26-35 and tip regions and sequence variability, including mutations and deletions at positions 9-25. Most (76.5%) of the sequences lead the GPGQ crown motif while the GPGQ/L/R/K substitution was observed in 18.8%. The number of N-linked glycosylation sites ranged from 0 to 4 per env C2-V3 amino acid sequence with only 37.5% of the sequences having all four N-Iinked glycosylation sites. The CXCR4- tropic viruses known to be associated with the presence of multiple ammo acid mutations were predominant (68.8%) among the studied population. Ten percent of the CCR5-tropic viruses showed Maraviroc associated resistant mutations. There was evidence of circulation of HIV-1 CRF35_AD in Nigeria, and multiple circulation of HIV-1 subtypes, with the predominance of HIV-1G. The predominance of CXCR4 -tropic viruses and presence of primary resistance to Maraviroc in 10% of CCR5-tropic viruses suggest the need for further investigation prior to introduction of coreceptor inhibitors like Maraviroc for management of HIV infection in Nigeria. Description: A Doctoral Degree Thesis in the Department of Virology submitted to the Faculty of Basic Medical Sciences in partial fulfillment of the requirement for the degree of Doctor of Philosophy of the University of Ibadan, Ibadan, Nigeria Tue, 01 Jan 2013 00:00:00 GMT http://adhlui.com.ui.edu.ng/jspui/handle/123456789/696 2013-01-01T00:00:00Z