Dynamics of Pre-Exposure (PrEP) Eligibility Because of Waxing and Waning of HIV Risk in Rakai, Uganda

BACKGROUND

We conducted a retrospective population-based study to describe longitudinal patterns of prevalence, incidence, discontinuation, resumption, and durability of substantial HIV risk behaviors (SHR) for pre-exposure prophylaxis (PrEP) eligibility.

METHODS

The study was conducted among HIV-negative study participants aged 15-49 years who participated in survey rounds of the Rakai Community Cohort Study between August 2011 and June 2018. Substantial HIV risk was defined based on the Uganda national PrEP eligibility as reporting sexual intercourse with >1 partner of unknown HIV status, nonmarital sex without a condom, having genital ulcers, or having transactional sex. Resumption of SHR meant resuming of SHR after stopping SHR, whereas persistence of SHR meant SHR on >1 consecutive visit. We used generalized estimation equations with log-binomial regression models and robust variance to estimate survey-specific prevalence ratios; Generalized estimation equations with modified Poisson regression models and robust variance to estimate incidence ratios for incidence, discontinuation, and resumption of PrEP eligibility.

FINDINGS

Incidence of PrEP eligibility increased from 11.4/100 person-years (pys) in the first intersurvey period to 13.9/100 pys (adjusted incidence rate ratios = 1.28; 95%CI = 1.10-1.30) and declined to 12.6/100 pys (adjusted incidence rate ratios = 1.06; 95%CI = 0.98-1.15) in the second and third intersurvey periods, respectively. Discontinuation rates of SHR for PrEP eligibility were stable (ranging 34.9/100 pys-37.3/100 pys; P = 0.207), whereas resumption reduced from 25.0/100 pys to 14.5/100 pys ( P < 0.001). PrEP eligibility episodes lasted a median time of 20 months (IQR = 10-51).

INTERPRETATION

Pre-exposure prophylaxis use should be tailored to the dynamic nature of PrEP eligibility. Preventive-effective adherence should be adopted for assessment of attrition in PrEP programs.

High Rates of Pre-exposure Prophylaxis Eligibility and Associated HIV Incidence in a Population With a Generalized HIV Epidemic in Rakai, Uganda

BACKGROUND

The utility of using pre-exposure prophylaxis (PrEP) eligibility assessments to identify eligibility in general populations has not been well studied in sub-Saharan Africa. We used the Rakai Community Cohort Study to conduct a cross-sectional analysis to estimate PrEP eligibility and a cohort analysis to estimate HIV incidence associated with PrEP eligibility.

METHODS

Based on Uganda's national PrEP eligibility tool, we defined eligibility as reporting at least one of the following HIV risks in the past 12 months: sexual intercourse with more than one partner of unknown HIV status; nonmarital sex act without a condom; sex engagement in exchange for money, goods, or services; or experiencing genital ulcers. We used log-binomial and modified Poisson models to estimate prevalence ratios for PrEP eligibility and HIV incidence, respectively.

FINDINGS

We identified 12,764 participants among whom to estimate PrEP eligibility prevalence and 11,363 participants with 17,381 follow-up visits and 30,721 person-years (pys) of observation to estimate HIV incidence. Overall, 29% met at least one of the eligibility criteria. HIV incidence was significantly higher in PrEP-eligible versus non-PrEP-eligible participants (0.91/100 pys versus 0.41/100 pys; P < 0.001) and independently higher in PrEP-eligible versus non-PrEP-eligible female participants (1.18/100 pys versus 0.50/100 pys; P < 0.001). Among uncircumcised male participants, HIV incidence was significantly higher in PrEP-eligible versus non-PrEP-eligible participants (1.07/100 pys versus 0.27/100 pys; P = 0.001), but there was no significant difference for circumcised male participants.

INTERPRETATION

Implementing PrEP as a standard HIV prevention tool in generalized HIV epidemics beyond currently recognized high-risk key populations could further reduce HIV acquisition and aid epidemic control efforts.

Temporal trends of early mortality and its risk factors in HIV-infected adults initiating antiretroviral therapy in Uganda

BACKGROUND

A decline in mortality rates during the first 12 months of antiretroviral therapy (ART) has been mainly linked to increased ART initiation at higher CD4 counts and at less advanced World Health Organization (WHO) clinical stages of HIV infection; however, the role of improved patient care has not been well studied. We estimated improvements in early mortality due to improved patient care.

METHODS

We conducted a retrospective cohort study of HIV-infected individuals ages 18 and older who initiated ART at the Mengo HIV Counseling and Home Care Clinic between 2006 and 2016. We conducted a mediation analysis using generalized structural equation models with inverse odds ratio weighting to estimate the natural direct and indirect effects of ART initiation time on early mortality.

FINDINGS

Among 6,847 patients, most were female (69%), with a median age of 32 (interquartile range [IQR] = 28-38), versus a median age of 38 (IQR = 32-45) for males. The median CD4 count at ART initiation increased from 142 cells/ul (95% confidence interval [CI] = 135-150) in 2006-2010 to 302 cells/ul (95% CI = 283-323) in 2015-2016 (p < 0·001). The number of patients at WHO clinical stages I/II increased from 52% in 2006-2010 to 78% in 2015-2016 (p < 0·001). Annual early mortality decreased from 8·8 deaths/100 person years (PYS) in 2006 to 2.5 deaths/100 pys in 2016 (p < 0·001). Mediation by CD4 counts and WHO clinical stages accounted for 54% of the total effect of ART initiation timing on early mortality. In comparison, 46% remained as the direct effect, reflecting the contribution of improved patient care.

INTERPRETATION

Improved patient care practices should be promoted as a strategy for reducing early mortality after ART initiation, above and beyond the effects from ART initiation at higher CD4 counts and less advanced WHO clinical stage alone.

FUNDING

This research was supported by the President's Emergency Plan for AIDS Relief (PEPFAR), the National Institute of Allergy and Infectious Diseases Division of Intramural Research, and the National Cancer Institute.

Scaling-up the Xpert MTB/RIF assay for the detection of tuberculosis and rifampicin resistance in India: An economic analysis

BACKGROUND

India is considering the scale-up of the Xpert MTB/RIF assay for detection of tuberculosis (TB) and rifampicin resistance. We conducted an economic analysis to estimate the costs of different strategies of Xpert implementation in India.

METHODS

Using a decision analytical model, we compared four diagnostic strategies for TB patients: (i) sputum smear microscopy (SSM) only; (ii) Xpert as a replacement for the rapid diagnostic test currently used for SSM-positive patients at risk of drug resistance (i.e. line probe assay (LPA)); (iii) Upfront Xpert testing for patients at risk of drug resistance; and (iv) Xpert as a replacement for SSM for all patients.

RESULTS

The total costs associated with diagnosis for 100,000 presumptive TB cases were: (i) US$ 619,042 for SSM-only; (ii) US$ 575,377 in the LPA replacement scenario; (iii) US$ 720,523 in the SSM replacement scenario; and (iv) US$ 1,639,643 in the Xpert-for-all scenario. Total cohort costs, including treatment costs, increased by 46% from the SSM-only to the Xpert-for-all strategy, largely due to the costs associated with second-line treatment of a higher number of rifampicin-resistant patients due to increased drug-resistant TB (DR-TB) case detection. The diagnostic costs for an estimated 7.64 million presumptive TB patients would comprise (i) 19%, (ii) 17%, (iii) 22% and (iv) 50% of the annual TB control budget. Mean total costs, expressed per DR-TB case initiated on treatment, were lowest in the Xpert-for-all scenario (US$ 11,099).

CONCLUSIONS

The Xpert-for-all strategy would result in the greatest increase of TB and DR-TB case detection, but would also have the highest associated costs. The strategy of using Xpert only for patients at risk for DR-TB would be more affordable, but would miss DR-TB cases and the cost per true DR-TB case detected would be higher compared to the Xpert-for-all strategy. As such expanded Xpert strategy would require significant increased TB control budget to ensure that increased case detection is followed by appropriate care.

Mortality trends from 2003 to 2009 among adolescents and young adults in rural Western Kenya using a health and demographic surveillance system

BACKGROUND

Targeted global efforts to improve survival of young adults need information on mortality trends; contributions from health and demographic surveillance system (HDSS) are required.

METHODS AND FINDINGS

This study aimed to explore changing trends in deaths among adolescents (15-19 years) and young adults (20-24 years), using census and verbal autopsy data in rural western Kenya using a HDSS. Mid-year population estimates were used to generate all-cause mortality rates per 100,000 population by age and gender, by communicable (CD) and non-communicable disease (NCD) causes. Linear trends from 2003 to 2009 were examined. In 2003, all-cause mortality rates of adolescents and young adults were 403 and 1,613 per 100,000 population, respectively, among females; and 217 and 716 per 100,000, respectively, among males. CD mortality rates among females and males 15-24 years were 500 and 191 per 100,000 (relative risk [RR] 2.6; 95% confidence intervals [CI] 1.7-4.0; p<0.001). NCD mortality rates in same aged females and males were similar (141 and 128 per 100,000, respectively; p = 0.76). By 2009, young adult female all-cause mortality rates fell 53% (χ(2) for linear trend 30.4; p<0.001) and 61.5% among adolescent females (χ(2) for linear trend 11.9; p<0.001). No significant CD mortality reductions occurred among males or for NCD mortality in either gender. By 2009, all-cause, CD, and NCD mortality rates were not significantly different between males and females, and among males, injuries equalled HIV as the top cause of death.

CONCLUSIONS

This study found significant reductions in adolescent and young adult female mortality rates, evidencing the effects of targeted public health programmes, however, all-cause and CD mortality rates among females remain alarmingly high. These data underscore the need to strengthen programmes and target strategies to reach both males and females, and to promote NCD as well as CD initiatives to reduce the mortality burden amongst both gender.