Incidences and factors associated with viral suppression or rebound among HIV patients on combination antiretroviral therapy from three counties in Kenya.

BACKGROUND

Limited data are available on the incidence and factors associated with viral rebound following viral suppression among HIV-infected individuals taking antiretroviral therapy (ART) in Kenya. Furthermore, the durability of viral suppression among HIV individuals taking ART is unknown. Information on incidence rates and factors associated with HIV viral load rebound and the durability of viral suppression (undetectable HIV copies in plasma) among HIV-infected individuals taking ART, will help improve the long-term management of HIV-infected individuals and explore approaches to long-term HIV remission or complete cure.

OBJECTIVES

The objectives of this study were to investigate the incidence rates of viral rebound following viral suppression, factors associated with viral rebound, and the durability of viral suppression among HIV-infected individuals on ART from Kilifi, Meru, and Nakuru counties in Kenya.

METHODS

This was a retrospective study involving 600 HIV-infected individuals taking combination ART (cART) and enrolled in comprehensive care centers (CCCs) at Malindi Sub-county Hospital, Nakuru Level 5 Hospital, and Meru Level 5 Hospital in Kenya. The medical files were inspected and medical history records abstracted for the selected participants. Participant laboratory data including HIV viral loads, types and history of ART, and treatment history of any opportunistic infections were abstracted using an abstraction checklist. Participants were grouped into those who achieved HIV viral suppression, with viral loads lower than the detection limit (LDL) (viral suppression), and those who experienced one or more detectable viral load measurements >40 copies/ml following the initial LDL (viral rebound). Durable viral suppression was defined as all viral load values at LDL over the 2-year period (2017-2019). Univariate and multivariate Poisson regression analyses were performed to assess the rates of viral rebound, as well as to investigate factors associated with it.

RESULTS

Out of 549 HIV-positive patients, 324/549 (59%) achieved HIV viral suppression (Meru 159/194 (82%), Nakuru 21/178 (12%), and Malindi 144/177 (81%)). The overall viral rebound rate was 41%, with site-specific viral rebound of 88.2%, 18.6%, and 18.0% in Nakuru, Malindi, and Meru, respectively. There was an overall rate of first viral rebound of 3.9 (95% confidence interval (CI) 6.9-14.4), 0.7 (95% CI 0.5-1.0), and 0.89 (95% CI 0.64-1.24) per 100 person-months in Nakuru, Malindi, and Meru, respectively. Good ART adherence (p = 0.0002), widow status (p = 0.0062), and World Health Organization (WHO) stage I (p = 0.0002) were associated with viral suppression, while poor ART adherence (p < 0.0001), WHO stage II (p = 0.0024), and duration on ART of 36 months (p = 0.0350) were associated with viral rebound.

CONCLUSIONS

The rate of viral suppression in patients on cART in the CCCs fell short of the WHO target. However, the study provides proof of evidence of undetectable viral load levels for more than 2 years, a sign that the United Nation's 2030 objective of controlling the risk of HIV transmission could be achieved.