Assessment of the tuberculosis case-finding and prevention cascade among people living with HIV in Zambia – 2018: a cross-sectional cluster survey

Abstract

Background The Ministry of Health Zambia recommends tuberculosis preventive treatment (TPT) with 6 months daily isoniazid for all people living with human immunodeficiency virus (HIV) after ruling out active tuberculosis disease. We sought to estimate the percentage of people living with HIV who progress through each stage of the tuberculosis case-finding and prevention cascade in two provinces with the highest tuberculosis burden in Zambia. Methods In this cross-sectional survey, we used a two-stage cluster sampling method. We sampled 12 healthcare facilities with probability proportional to size. Patient volume determined facility cluster size. During October 2018, from each facility we systematically sampled medical records of adults and children living with HIV. Our primary outcome of interest was TPT initiation rate among eligible people living with HIV, weighted for complex survey design. The Rao-Scott adjusted chi-square test was used to test for differences in TPT initiation rate and other indicators from the tuberculosis prevention cascade by age group and province of residence. Additionally, we conducted semi-structured interviews with healthcare workers at each facility to assess TPT knowledge and identify challenges to its implementation. Results We sampled 482 records of people living with HIV (including 128 children living with HIV). Excluding two people diagnosed with tuberculosis disease before enrollment in HIV care, 93.4% underwent tuberculosis symptom screening. Of those, 4.7% were diagnosed with tuberculosis disease and 95.3% were TPT-eligible, of whom 24.7% initiated TPT. TPT initiation was lower among eligible children (7.7%) compared with adults (25.2%, p = 0.03) and Copperbelt residents (3.1%) compared with Lusaka residents (35.8%, p < 0.01). TPT completion rate was 38.4% among people living with HIV who initiated the 6-month course. Among interviewed healthcare workers, 58.3% (unweighted) incorrectly relayed the number of symptoms needed for a positive tuberculosis symptom screen, 83.3% (unweighted) reported insufficient isoniazid stockpile for completion at the time of TPT initiation, and only 27.3% (unweighted) reported receiving TPT-specific training. Conclusions TPT uptake among people living with HIV in Zambia is challenged by inconsistent tuberculosis screening, lack of TPT training for healthcare workers, and supply chain inefficiencies. Addressing these barriers may increase TPT initiations and improve outcomes among people living with HIV.

Drop‐offs in the isoniazid preventive therapy cascade among children living with HIV in western Kenya, 2015–2019

“…Our findings, based on a large cohort of CLHIV aged 1–14 years from western Kenya (a region known for its high TB/HIV prevalence), contribute to the limited literature on IPT initiation and completion among CLHIV from high TB/HIV burden countries. The uptake of IPT among CLHIV in Kenya still falls short of the global target of >90% [ 19 ] and could be lagging behind that in adults living with HIV as reported by studies from other high TB prevalence countries [ 20 , 21 ]. These findings strengthen the evidence from previous Kenyan studies that reported suboptimal IPT initiation among CLHIV, although those studies were conducted in regions of the country with lower TB/HIV prevalence, were based on small sample sizes and did not include all age groups [ 12 , 22 , 23 ].…”

Addressing TB-related mortality in adults living with HIV: a review of the challenges and potential solutions

“… 27 A cross-sectional study from Zambia also found low TPT completion rates with only 38% of the 25% of eligible PLHIV who initiated TPT completing treatment. 28 …”

“… 84 Improving the efficiency of healthcare systems and effective training on TPT may also allow for better implementation of TPT and reduced TB mortality in PLHIV. 27 , 28 …”

“…27 A cross-sectional study from Zambia also found low TPT completion rates with only 38% of the 25% of eligible PLHIV who initiated TPT completing treatment. 28 Challenges with the diagnosis of TB in people living with HIV Interventions to increase the likelihood of earlier diagnoses for both HIV and TB reduce mortality in adults with HIV/TB co-infection, since factors such as having a higher CD4 level and being on ART are associated with lower mortality. 29 However, sputum, which remains the mainstay of TB diagnostic testing, is more difficult to obtain in the adults with HIV/TB co-infection, 30 due to paucibacillary disease and the lack of cavitation, which are associated with a higher rate of smear negative disease.…”

“…84 Improving the efficiency of healthcare systems and effective training on TPT may also allow for better implementation of TPT and reduced TB mortality in PLHIV. 27,28 Improving TB screening and diagnosis Wider implementation of TB screening in PLHIV is essential to reducing TB-related mortality. The WHO consolidated guidelines on tuberculosis recommend that PLHIV should be screened systematically for TB at every visit to a healthcare facility.…”