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Dive into the research topics where Andrew Abaasa is active.

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Featured researches published by Andrew Abaasa.


BMC Health Services Research | 2008

Good adherence to HAART and improved survival in a community HIV/AIDS treatment and care programme: the experience of The AIDS Support Organization (TASO), Kampala, Uganda.

Andrew Abaasa; Jim Todd; Kenneth Ekoru; Joan N. Kalyango; Jonathan Levin; Emmanuel Odeke; Charles Karamagi

BackgroundPoor adherence to highly active antiretroviral therapy (HAART) may result in treatment failure and death. Most reports of the effect of adherence to HAART on mortality come from studies where special efforts are made to provide HAART under ideal conditions. However, there are few reports of the impact of non-adherence to HAART on mortality from community HIV/AIDS treatment and care programmes in developing countries. We therefore conducted a study to assess the effect of adherence to HAART on survival in The AIDS Support Organization (TASO) community HAART programme in Kampala, Uganda.MethodsThe study was a retrospective cohort of 897 patients who initiated HAART at TASO clinic, Kampala, between May 2004 and December 2006. A total of 7,856 adherence assessments were performed on the data. Adherence was assessed using a combination of self-report and pill count methods. Patients who took ≤ 95% of their regimens were classified as non-adherent. The data was stratified at a CD4 count of 50 cells/mm3. Kaplan Meier curves and Cox proportional hazards regression models were used in the analysis.ResultsA total of 701 (78.2%) patients had a mean adherence to ART of > 95%. The crude death rate was 12.2 deaths per 100 patient-years, with a rate of 42.5 deaths per 100 patient-years for non-adherent patients and 6.1 deaths per 100 patient-years for adherent patients. Non-adherence to ART was significantly associated with mortality. Patients with a CD4 count of less than 50 cells/mm3 had a higher mortality (HR = 4.3; 95% CI: 2.22–5.56) compared to patients with a CD4 count equal to or greater than 50 cells/mm3 (HR = 2.4; 95% CI: 1.79–2.38).ConclusionOur study showed that good adherence and improved survival are feasible in community HIV/AIDS programmes such as that of TASO, Uganda. However, there is need to support community HAART programmes to overcome the challenges of funding to provide sustainable supplies particularly of antiretroviral drugs; provision of high quality clinical and laboratory support; and achieving a balance between expansion and quality of services. Measures for the early identification and treatment of HIV infected people including home-based VCT and HAART should be strengthened.


Sexually Transmitted Infections | 2011

HIV and syphilis prevalence and associated risk factors among fishing communities of Lake Victoria, Uganda.

Gershim Asiki; Juliet Mpendo; Andrew Abaasa; Collins Agaba; Annet Nanvubya; Leslie Nielsen; Janet Seeley; Pontiano Kaleebu; Heiner Grosskurth; Anatoli Kamali

Objectives Recent publications suggest that fishing populations may be highly affected by the HIV epidemic. However, accurate data are scarce. The authors determined HIV and syphilis prevalence and associated risk factors in a fishing population of Lake Victoria in Uganda. Methods 10 188 volunteers aged ≥13 years from a census carried out in five fishing communities between February and August 2009 were invited to attend central study clinics established in each community. After informed consent, 2005 randomly selected volunteers responded to socio-demographic and risk assessment questions, provided blood for HIV testing and 1618 volunteers were also tested for syphilis. Risk factors were analysed using logistic regression. Results HIV and active syphilis (rapid plasma reagin titre ≥1:8) prevalences were 28.8% (95% CI 26.8 to 30.8) and 4.3% (95% CI 3.3 to 5.4), respectively, and high risk sexual behaviour was frequently reported. HIV prevalence was independently associated with female sex, increasing age, occupation (highest in fishermen), relationship to household head, self-reported genital sores and knowledge of an HIV infected partner. Alcohol consumption, syphilis and sexually transmitted infections (STIs) reported by health workers were associated with HIV in women, and genital discharge and inconsistent condom use in men. Syphilis prevalence was independently associated with age and alcohol consumption in women, and recent genital sores and sex under the influence of drugs in men. Conclusion This fishing population characterised by a very high HIV prevalence, high syphilis prevalence and frequently reported sexual risk behaviours, urgently needs improved STI services and targeted behavioural interventions.


Sexually Transmitted Diseases | 2012

High HIV incidence and socio-behavioral risk patterns in fishing communities on the shores of Lake Victoria, Uganda.

Janet Seeley; Jessica Nakiyingi-Miiro; Anatoli Kamali; Juliet Mpendo; Gershim Asiki; Andrew Abaasa; De Bont J; Leslie Nielsen; Pontiano Kaleebu; Chivtum Study Team

Background: We report on HIV acquisition and its associated risk factors in 5 fishing communities on the shores of Lake Victoria in Uganda. A cohort of 1000 HIV-uninfected at-risk volunteers aged 13 to 49 years were recruited in 2009 and followed up for 18 months. Methods: At enrollment and semiannual visits, socio-demographic and risk behavior data were collected through a structured questionnaire and blood samples tested for HIV and syphilis. Detailed life histories were collected from 78 volunteers using in-depth interviews. Results: Of the 1000 volunteers enrolled, 919 (91.9%) were followed up, with 762 (76.2%) reaching the study end points (either seroconverted or completed 4 visits). There were 59 incident cases in 1205.6 person-years at risk (PYAR), resulting in an incidence rate of 4.9 (95% CI = 3.8 to 6.3) per 100 PYAR. The highest HIV incidence rates were among those working in bars (9.8/100 PYAR [4.7–20.6]), protestants (8.6/100 PYAR [5.8–12.7]), those aged 13 to 24 years (7.5/100 PYAR [5.2–11.0]), and new immigrants (6.6/100 PYAR [4.9–8.9]). HIV infection was independently associated with being young (adjusted hazard ratio (aHR) = 2.5 [95% CI = 1.3–4.9]), reporting genital sores/discharge recently (aHR = 2.8 [1.6–5.0]), regular alcohol consumption (aHR = 3.3 [1.6–6.1]), use of marijuana (aHR = 2.9 [1.0–8.0]), cigarette smoking (aHR = 3.6 [1.4–9.3]), and religion (compared with Catholics, Protestants had aHR = 2.7 [1.4–5.3] and Muslims had aHR = 2.3 [1.1–4.8]). Conclusions: These fishing communities experienced high HIV infection, which was mainly explained by high-risk behavior. There is an urgent need to target HIV prevention and research efforts to this vulnerable and neglected group.


PLOS ONE | 2011

HIV Incidence and Risk Factors for Acquisition in HIV Discordant Couples in Masaka, Uganda: An HIV Vaccine Preparedness Study

Eugene Ruzagira; Symon Wandiembe; Andrew Abaasa; Agnes N. Bwanika; Ubaldo Bahemuka; Pauli N. Amornkul; Matthew Price; Heiner Grosskurth; Anatoli Kamali

Objectives To determine the incidence of and risk factors for HIV acquisition in a cohort of HIV-uninfected partners from HIV discordant couples in Masaka, Uganda, and to establish its suitability for HIV vaccine trials. Methods HIV-uninfected adults living in HIV discordant couple relationships were enrolled and followed for 2 years. Interviews, medical investigations, HIV counseling and testing, syphilis and urine pregnancy (women) tests were performed at quarterly visits. Sexual risk behaviour data were collected every 6 months. Results 495 participants were enrolled, of whom 34 seroconverted during 786.6 person-years of observation (PYO). The overall HIV incidence rate [95% confidence interval (CI)] was 4.3 [3.1–6]; and 4.3 [2.8–6.4] and 4.4 [2.5–8] per 100 PYO in men and women respectively. Independent baseline predictors for HIV acquisition were young age [18–24 (aRR = 4.1, 95% CI 1.6–10.8) and 25–34 (aRR = 2.7, 95% CI 1.2–5.8) years]; alcohol use (aRR = 2.6, 95% CI 1.1–6); and reported genital discharge (aRR = 3.4, 95% CI 1.6–7.2) in the past year. Condom use frequency in the year preceding enrolment was predictive of a reduced risk of HIV acquisition [sometimes (aRR = 0.4, 95% CI 0.2–0.8); always (aRR = 0.1, 95% CI 0.02–0.9)]. In the follow-up risk analysis, young age [18–24 (aRR = 6.2, 95% CI 2.2–17.3) and 25-34 (aRR = 2.3, 95% CI 1.1–5.0) years], reported genital discharge (aRR = 2.5, 95% CI 1.1–5.5), serological syphilis (aRR 3.2, 95% CI 1.3–7.7) and the partner being ART naïve (aRR = 4.8, 95% CI 1.4–16.0) were independently associated with HIV acquisition. There were no seroconversions among participants who reported consistent condom use during the study. Conclusions The study has identified important risk factors for HIV acquisition among HIV discordant couples. HIV-uninfected partners in discordant couples may be a suitable population for HIV vaccine efficacy trials. However, recent confirmation that ART reduces heterosexual HIV transmission may make it unfeasible to conduct HIV prevention trials in this population.


PLOS ONE | 2011

Prevalence and Incidence of HIV in a Rural Community-Based HIV Vaccine Preparedness Cohort in Masaka, Uganda

Eugene Ruzagira; Symon Wandiembe; Andrew Abaasa; Jonathan Levin; Agnes N. Bwanika; Ubaldo Bahemuka; Matthew Price; Anatoli Kamali

Background Local HIV epidemiology data are critical in determining the suitability of a population for HIV vaccine efficacy trials. The objective of this study was to estimate the prevalence and incidence of, and determine risk factors for HIV transmission in a rural community-based HIV vaccine preparedness cohort in Masaka, Uganda. Methods Between February and July 2004, we conducted a house-to-house HIV sero-prevalence survey among consenting individuals aged 18–60 years. Participants were interviewed, counseled and asked to provide blood for HIV testing. We then enrolled the HIV uninfected participants in a 2-year HIV sero-incidence study. Medical evaluations, HIV counseling and testing, and sample collection for laboratory analysis were done quarterly. Sexual risk behaviour data was collected every 6 months. Results The HIV point prevalence was 11.2%, and was higher among women than men (12.9% vs. 8.6%, P = 0.007). Risk factors associated with prevalent HIV infection for men were age <25 years (aOR = 0.05, 95% CI 0.01–0.35) and reported genital ulcer disease in the past year (aOR = 2.17, 95% CI 1.23–3.83). Among women, being unmarried (aOR = 2.59, 95% CI 1.75–3.83) and reported genital ulcer disease in the past year (aOR = 2.40, 95% CI 1.64–3.51) were associated with prevalent HIV infection. Twenty-one seroconversions were recorded over 2025.8 person-years, an annual HIV incidence of 1.04% (95% CI: 0.68–1.59). The only significant risk factor for incident HIV infection was being unmarried (aRR = 3.44, 95% CI 1.43–8.28). Cohort retention after 2 years was 87%. Conclusions We found a high prevalence but low incidence of HIV in this cohort. HIV vaccine efficacy trials in this population may not be feasible due to the large sample sizes that would be required. HIV vaccine preparatory efforts in this setting should include identification of higher risk populations.


Tropical Medicine & International Health | 2014

A pilot study to evaluate aflatoxin exposure in a rural Ugandan population

Gershim Asiki; Janet Seeley; Chou Srey; Kathy Baisley; Tracey Lightfoot; Kaaya Archileo; Dorice Agol; Andrew Abaasa; Katie Wakeham; Michael N. Routledge; Christopher P. Wild; Robert Newton; Yun Yun Gong

The fungal metabolite aflatoxin is a common contaminant of foodstuffs, especially when stored in damp conditions. In humans, high levels can result in acute hepatic necrosis and death, while chronic exposure is carcinogenic. We conducted a pilot study nested within an existing population cohort (the General Population Cohort), to assess exposure to aflatoxin, among people living in rural south‐western Uganda.


Trials | 2013

Long-term consistent use of a vaginal microbicide gel among HIV-1 sero-discordant couples in a phase III clinical trial (MDP 301) in rural south-west Uganda

Andrew Abaasa; Angela M. Crook; Mitzy Gafos; Zacchaeus Anywaine; Jonathan Levin; Symon Wandiembe; Ananta Nanoo; Andrew Nunn; Sheena McCormack; Richard Hayes; Anatoli Kamali

BackgroundA safe and effective vaginal microbicide could substantially reduce HIV acquisition for women. Consistent gel use is, however, of great importance to ensure continued protection against HIV infection, even with a safe and effective microbicide. We assessed the long-term correlates of consistent gel use in the MDP 301 clinical trial among HIV-negative women in sero-discordant couples in south-west Uganda.MethodsHIV-negative women living with an HIV-infected partner were enrolled between 2005 and 2008, in a three-arm phase III microbicide trial and randomized to 2% PRO2000, 0.5% PRO2000 or placebo gel arms. Follow-up visits continued up to September 2009. The 2% arm was stopped early due to futility and the 229 women enrolled in this arm were excluded from this analysis. Data were analyzed on 544 women on the 0.5% and placebo arms who completed at least 52 weeks of follow-up, sero-converted or became pregnant before 52 weeks. Consistent gel use was defined as satisfying all of the following three conditions: (i) reported gel use at the last sex act for at least 92% of the 26 scheduled visits or at least 92% of the visits attended if fewer than 26; (ii) at least one used applicator returned for each visit for which gel use was reported at the last sex act; (iii) attended at least 13 visits (unless the woman sero-converted or became pregnant during follow-up). Logistic regression models were fitted to investigate factors associated with consistent gel use.ResultsOf the 544 women, 473 (86.9%) were followed for at least 52 weeks, 29 (5.3%) sero-converted and 42 (7.7%) became pregnant before their week 52 visit. Consistent gel use was reported by 67.8%. Women aged 25 to 34 years and those aged 35 years or older were both more than twice as likely to have reported consistently using gel compared to women aged 17 to 24 years. Living in a household with three or more rooms used for sleeping compared to one room was associated with a twofold increase in consistent gel use.ConclusionIn rural Uganda younger women and women in houses with less space are likely to require additional support to achieve consistent microbicide gel use.Trial registrationProtocol Number ISRCTN64716212


Contemporary Clinical Trials | 2015

Safety of discontinuing cotrimoxazole prophylaxis among HIV infected adults on anti-retroviral therapy in Uganda (COSTOP trial): Design

Zacchaeus Anywaine; Andrew Abaasa; Jonathan Levin; Ronnie Kasirye; Anatoli Kamali; Heiner Grosskurth; Paula Munderi; Andrew Nunn

Introduction Cotrimoxazole (CTX) prophylaxis is recommended by the World Health Organisation for HIV infected persons. However, once HIV infected patients have commenced ART in resource limited settings, the benefits of continued CTX prophylaxis are not known. The few studies that investigated the safety of discontinuing CTX prophylaxis in these settings had limitations due to their design. Materials and methods COSTOP is a randomised double blind placebo controlled non-inferiority trial among HIV infected Ugandan adults stabilised on anti-retroviral treatment (ART). Participants with CD4 count of 250 or more cells/mm3 are randomised to two arms: the intervention arm in which CTX is discontinued and the control arm in which CTX prophylaxis is continued. The study aims to assess whether the intervention regimen is not inferior, with respect to the incidence of pre-defined CTX-preventable events, to the control regimen and superior with respect to the incidence of haematological adverse events. Discussion Studies that have previously evaluated the safety of discontinuing CTX prophylaxis among HIV infected adults in resource limited settings have provided moderate to low quality evidence owing in part to methodological limitations. COSTOP is designed and conducted with sufficient rigour to answer this question. The results of the trial will assist in guiding policy recommendations. Conclusion This paper describes the design and methodological considerations important for the conduct of CTX cessation studies.


Tropical Medicine & International Health | 2009

Haematological and biochemistry laboratory abnormalities associated with splenomegaly in asymptomatic adults in Masaka, Uganda: implications for HIV biomedical prevention trials

Eugene Ruzagira; Andrew Abaasa; Jonathan Levin; Ubaldo Bahemuka; Agnes N. Bwanika; Pauli N. Amornkul; Matthew Price; Heiner Grosskurth; Anatoli Kamali

Objectives  To assess the degree of haematological and biochemistry abnormalities associated with splenomegaly in asymptomatic adults in order to determine whether they may be eligible for inclusion in HIV biomedical prevention trials.


Vaccine | 2016

Comparison of HIV incidence estimated in clinical trial and observational cohort settings in a high risk fishing population in Uganda: Implications for sample size estimates.

Andrew Abaasa; Gershim Asiki; Matthew Price; Eugene Ruzagira; Freddie Kibengo; Ubaldo Bahemuka; Patricia Fast; Anatoli Kamali

BACKGROUND Clinical trial participants may differ from the source population due to the demands of trial participation and self-selection, inadvertent selection of a lower-risk group, or both. We investigated the HIV risk status of volunteers in a Simulated Vaccine Efficacy Trial (SiVET) nested within a prospective observational cohort of fisher folks in South Western Uganda. METHODS Volunteers aged 18-49 years, at high risk for HIV from fishing communities in Masaka district were recruited into an observational cohort and followed quarterly. High risk was defined as a self-report, of at least one of the following in the past three months; sexually transmitted infections, unprotected sex with >1 partner or a new sexual partner, use of recreational drugs, weekly alcohol use, and/or frequent travel. Volunteers who had at least three months of follow-up in the observational cohort were consecutively enrolled in SiVET, administered Hepatitis B vaccine at months (0, 1, 6) and followed-up three days post vaccinations to mimic a vaccine trial schedule. HIV incidence over the next 12 months was compared between SiVET and the observational cohort studies. RESULTS Between January 2012 and February 2013, 575 individuals were enrolled in the observational cohort, of whom 282 were enrolled in SiVET between July 2012 and February 2013. Despite similar pattern of reported risk behaviour in both studies, HIV incidence was higher in observational cohort, 11.4 cases/100 PYO [95% CI: 7.4-17.7] compared to 3.8 [95% CI: 2.0-7.0] in SiVET (p<0.01). SiVET volunteers tended to be men, having some education and longer-term residents, all factors that are also associated with lower HIV risk. CONCLUSION We observed a lower HIV incidence in SiVET than in the observational cohort. The two populations differed significantly in demographics but not in reported risk. HIV incidence estimates from observational cohorts must be used with caution to estimate the trial study size.

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Gershim Asiki

Uganda Virus Research Institute

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Jonathan Levin

University of the Witwatersrand

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Eugene Ruzagira

Uganda Virus Research Institute

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Ubaldo Bahemuka

Uganda Virus Research Institute

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Andrew Nunn

University College London

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