Factors associated with HIV Seroconversion and facilitators and barriers for concurrent use of methadone and antiretroviral therapy among persons with opioid use disorder in Kisauni Mat Clinic, Mombasa County, Kenya.

Abstract

Background: Methadone Maintenance Treatment (MMT) is the use of an approved drug, in combination with counselling and behavioural therapies, to provide a 'whole-patient approach' to treating substance use disorder. Kenya adopted MMT in 2014 as part of a multi-strategy approach to preventing the spread of HIV infections among opioid injectors. However, there is limited data on the impact of MMT on HIV in the Kisauni MAT Clinic. Objectives: To determine the prevalence of HIV coinfection with HCV, HBV, and TB co-infections among MMT clients in the Kisauni MAT clinic, determine the HIV seroconversion rate, identify factors associated with HIV seroconversion, and explore the facilitators and barriers to concurrent methadone and antiretroviral therapy (ART) use. Methods: This was a retrospective cohort study among those with opioid use disorder (OUD) enrolled in the Kisauni MAT clinic, in Mombasa County, Kenya. A sequential explanatory approach was used to collect quantitative and qualitative data. All the records for the clients enrolled between 2015 and 2019, and their HIV outcomes as of December 2022 were reviewed. In-depth interviews with the identified HIV seroconverts were conducted using a developed interview guide. An HIV-seroconvert was defined as any HIV-negative MMT client at enrolment who tested positive during a follow-up test. Descriptive analysis was done using measures of central tendency for continuous data and proportions for categorical data. To determine independent predictors of HIV seroconversion, Fisher’s exact test and chi-square test were used. All factors with a p-value ≤ 0.2 at bivariate analysis were included in a logistic regression model. Factors with a p-value ≤ 0.05 and their Risk Ratios (RR) were considered significant. Qualitative data were transcribed and themes were manually categorized into key themes and sub-themes. Results: Of the 936 records reviewed, 729 were analysed; 91.1% were male and 61% were non-injectors. HIV co-infection was as follows: HIV/Hepatitis C Virus (HCV) at 78/729 (10.7%), while HIV/Hepatitis B Virus (HBV) and HIV/Tuberculosis (TB) were at 4.7% (34/729) and 3.8% (28/729) each. In 3,386.9 total follow-up years, 14 (1.9%) clients seroconverted to HIV at a rate of 0.4 (95% CI:0.2–0.7) new infections per 100 person-years (PY) with females having a higher seroconversion rate of 1.9/100 PY (95% CI:0.7–4.2) compared to males at 0.3/100 PY (95%CI:0.1–0.5) PY. Injectors and non-injectors both seroconverted at 0.4/100 PY (95% CI:0.2–1.0 and 0.2–0.8, respectively), with a rate ratio of 1.1 (95% CI:0.3–3.7). The factors associated with HIV seroconversion were being female (Adjusted Risk Ratio [aRR] of 8.01; 95% CI: 2.64, 24.3), and a positive Hepatitis C test (aRR of 3.7; 95% CI;1.08, 12.42). Condom use during sex reduced the risk of HIV seroconversion by 74% (aRR 0.26: 95% CI; 0.09, 0.8). HIV seroconverts identified drug-using peers, community stigma, transport costs, pill burden, and side effects at the initiation of concurrent ART and methadone, as barriers to treatment adherence. Family support and accessibility of methadone at sunset during Ramadhan facilitated adherence. Conclusion: There was no difference in HIV seroconversion rates between injectors and non-injectors who are on the MMT program (RR of 1.1; 95%CI:0.3–3.7). A positive Hepatitis C test was an independent predictor for HIV seroconversion. Females were fewer in number but were independently at higher risk of HIV seroconversion. Social and economic barriers negatively affected treatment adherence among the HIV seroconverts. Recommendation: Scale up the program by enrolling more people with opioid use disorder in the clinic, closely monitoring Hepatitis C-positive clients for HIV risky behaviors, and addressing social and economic barriers to improve ART and MMT adherence.