The shift in tuberculosis timing among people living with HIV in the course of antiretroviral therapy scale-up in Malawi

Despite antiretroviral therapy (ART) rollout, most cases of tuberculosis among people with HIV in Adama, Ethiopia, occur before ART initiation

INTRODUCTION

Although antiretroviral therapy (ART) leads to reduced tuberculosis (TB) incidence in people with HIV (PWH), ART recipients remain at higher risk of TB compared to HIV-seronegative people. With accelerated ART rollout in sub-Saharan Africa, increasing proportions of TB cases among PWH in people receiving long-term ART have been reported.

OBJECTIVE

To determine TB notifications among PWH by ART status in a mainly urban uptake area in Ethiopia during an 8-year period in connection to the introduction of the 'test-and-treat' strategy for HIV.

METHODS

PWH were identified from registers at health facilities providing ART in Adama and surrounding areas, Ethiopia 2015-2022. Annual TB notifications were compared over time. PWH within TB were categorized by ART status at the time of TB diagnosis (pre-ART TB: TB diagnosed before or ≤6 months after starting ART; ART-associated TB: TB diagnosed >6 months after starting ART).

RESULTS

Among a total of 8,926 PWH, 993 had been diagnosed with TB (11.1%); mean age 40.0 years [SD 11.8], 53.5% were men). Throughout the study period, most TB cases had been notified before ART initiation (617/993; 62.1%). ART-associated TB cases constituted a mean of 37.4% (range 23.8%-44.2%) of all TB cases among PWH annually. Median time from ART initiation to TB diagnosis among ART-associated TB was 6.0 years.

CONCLUSION

TB notifications among PWH in this area did not decrease 2015-2022, implying persistently high risk of TB among PWH in this setting. Most TB cases occurred in ART-naïve persons, illustrating late HIV diagnosis in this population.

Characteristics of TPT initiation and completion among people living with HIV

BACKGROUND

TB preventive treatment (TPT) reduces morbidity and mortality among people living with HIV (PLHIV). Despite the successful scale-up of TPT in Malawi, monitoring and evaluation have been suboptimal. We utilized the Malawi Population-Based HIV Impact Assessment (MPHIA) 2020-2021 survey data to estimate TPT uptake and completion among self-reported HIV-positive persons.

METHODS

We estimated the proportion of HIV-positive respondents who had ever undergone TPT, and determined the percentage of those currently on TPT who had completed more than 6 months of treatment. Bivariate and multivariable logistic regression were performed to calculate the odds ratios for factors associated with ever-taking TPT. All variables were self-reported, and the analysis was weighted and accounted for in the survey design.

RESULTS

Of the HIV+ respondents, 38.8% (95% CI 36.4-41.3) had ever taken TPT. The adjusted odds of ever taking TPT were 8.0 and 5.2 times as high in the Central and Southern regions, respectively, compared to the Northern region; 1.9 times higher among those in the highest wealth quintile, and 2.1 times higher for those on antiretroviral therapy >10 years. Of those currently taking TPT, 56.2% completed >6 months of TPT.

CONCLUSION

These results suggest low TPT uptake and >6 months' completion rates among self-reported HIV+ persons. Initiatives to create demand and strengthen adherence would improve TPT uptake.

Incidence and factors associated with active tuberculosis among people living with HIV after long-term antiretroviral therapy in Thailand: a competing risk model

BACKGROUND

Antiretroviral therapy (ART) is known to reduce tuberculosis (TB) incidence among people living with HIV (PLWH). However, studies describing the impact of long-term ART and CD4 count recovery on TB incidence remain scarce due to limited follow up in previous studies. We evaluated TB incidence in a long-term cohort of PLWH on ART in Thailand.

METHODS

We conducted an analysis of PLWH aged ≥ 18 years who started ART between 1996 and December 2020. Participants were followed up every 6 months for routine HIV care. TB risk factors, body mass index (BMI), physical examination and full differential blood counts were evaluated at each clinic visit, and CD4 cell counts and HIV RNA every 12 months. Participants diagnosed with TB > 3 months after starting ART were classified as incident cases. Time to event models with death as a competing risk, were used to derive the TB cumulative incidence function (CIF) after ART initiation, and assess time-updated factors associated with incident TB using a six month lag.

RESULTS

A total of 2,636 PLWH contributing 24,229 person years (PY) of follow-up on ART were analysed. Median age was 32.0 (IQR 27.4-37.6) years; 67.5% were male. Median CD4 cell count at ART initiation was 264 (IQR 167-379) cells/mm³ and median follow-up duration was 7.6 (IQR 1.9-15.7) years. During follow-up, 113 PLWH developed TB. The probability of incident TB was 0.7%, 1.7%, 3.3% and 4.3%, at 1, 2, 5 and 7 years after ART initiation, respectively. TB CIF was highest among participants with CD4 < 50 cells/mm³. The overall crude incidence of TB was 4.66 (95% CI 3.87-5.60) per 1000 PY. Low CD4 count, BMI < 18 kg/m², and substance use in the previous six months were significantly associated with incident TB. Incidence declined with time on suppressive ART, but remained higher than the Thai general population 7 years after ART initiation (2.2 vs 1.5/1000 PY, respectively).

CONCLUSION

Despite a marked reduction in TB incidence following ART, ongoing TB risk remains high among PLWH, despite long-term suppressive ART. Those with low CD4 cell counts, who are underweight, or currently having substance abuse should be carefully monitored.

The shift in tuberculosis timing among people living with HIV in the course of antiretroviral therapy scale-up in Malawi

Introduction

Although the use of antiretroviral therapy (ART) reduces HIV‐associated tuberculosis (TB), patients living with HIV receiving ART remain at a higher risk of developing TB compared to those without HIV. We investigated the incidence of TB and the proportion of HIV‐associated TB cases among patients living with HIV who are receiving ART.

Methods

The study used TB registration and ART programme data collected between 2008 and 2017 from an integrated, public clinic in urban Lilongwe, Malawi. ART initiation was based on either WHO clinical staging or CD4 cell count. The CD4 thresholds for ART initiation eligibility was initially 250 cells/μL then changed to 350 cells/μL in 2011, 500 cells/μL in 2014 and to universal treatment upon diagnosis from 2016. Using TB registration data, we calculated the proportion of TB/HIV patients who were already on ART when they registered for TB treatment by year of TB registration. ART registration data were used to examine TB incidence by calendar year of ART follow‐up and by time on ART.

Results

The overall proportion of TB/patients living with HIV who started TB treatment while on ART increased from 21% in 2008 to 81% in 2017 but numbers remained relatively constant at 500 TB cases annually. The overall incidence rate of TB among patients on ART was 1.35/100 person‐years (95% CI 1.28 to 1.42). The incidence of TB by time on ART decreased from 6.4/100 person‐years in the first three months of ART to 0.4/100 person‐years after eight years on ART. TB incidence was highest in the first month on ART. The annual rate of TB among patients on ART rapidly decreased each calendar year and stabilized at 1% after 2013. Although the risk of developing TB decreased with year of ART initiation in univariable analysis, there was no significant association after adjusting for sex, age and reason for ART eligibility.

Conclusions

The decline in TB incidence over calendar years suggests protective effects of early ART initiation. The high TB incidence within the first month of ART highlights the need for more sensitive tools such as X‐ray and GeneXpert to identify patients living with HIV who have clinical and subclinical TB disease at ART initiation.

Extrapulmonary tuberculosis in HIV-infected patients in rural Tanzania: The prospective Kilombero and Ulanga antiretroviral cohort

BACKGROUND

In sub-Saharan Africa, diagnosis and management of extrapulmonary tuberculosis (EPTB) in people living with HIV (PLHIV) remains a major challenge. This study aimed to characterize the epidemiology and risk factors for poor outcome of extrapulmonary tuberculosis in people living with HIV (PLHIV) in a rural setting in Tanzania.

METHODS

We included PLHIV >18 years of age enrolled into the Kilombero and Ulanga antiretroviral cohort (KIULARCO) from 2013 to 2017. We assessed the diagnosis of tuberculosis by integrating prospectively collected clinical and microbiological data. We calculated prevalence- and incidence rates and used Cox regression analysis to evaluate the association of risk factors in extrapulmonary tuberculosis (EPTB) with a combined endpoint of lost to follow-up (LTFU) and death.

RESULTS

We included 3,129 subjects (64.5% female) with a median age of 38 years (interquartile range [IQR] 31-46) and a median CD4+ cell count of 229/μl (IQR 94-421) at baseline. During the median follow-up of 1.25 years (IQR 0.46-2.85), 574 (18.4%) subjects were diagnosed with tuberculosis, whereof 175 (30.5%) had an extrapulmonary manifestation. Microbiological evidence by Acid-Fast-Bacillus stain (AFB-stain) or Xpert® MTB/RIF was present in 178/483 (36.9%) patients with pulmonary and in 28/175 (16.0%) of patients with extrapulmonary manifestations, respectively. Incidence density rates for pulmonary Tuberculosis (PTB and EPTB were 17.9/1000person-years (py) (95% CI 14.2-22.6) and 5.8/1000 py (95% CI 4.0-8.5), respectively. The combined endpoint of death and LTFU was observed in 1058 (33.8%) patients, most frequently in the subgroup of EPTB (47.2%). Patients with EPTB had a higher rate of the composite outcome of death/LTFU after TB diagnosis than with PTB [HR 1.63, (1.14-2.31); p = 0.006]. The adjusted hazard ratios [HR (95% CI)] for death/LTFU in EPTB patients were significantly increased for patients aged >45 years [HR 1.95, (1.15-3.3); p = 0.013], whereas ART use was protective [HR 0.15, (0.08-0.27); p <0.001].

CONCLUSIONS

Extrapulmonary tuberculosis was a frequent manifestation in this cohort of PLHIV. The diagnosis of EPTB in the absence of histopathology and mycobacterial culture remains challenging even with availability of Xpert® MTB/RIF. Patients with EPTB had increased rates of mortality and LTFU despite early recognition of the disease after enrollment.