Title

High prevalence of latent tuberculosis infection among people living with HIV in Thailand, 2022

Presenter

Rom Luengwattanapong

Authors

R. Luengwattanapong¹, T. Palakawong Na Ayuthaya², S. Jirajariyavej³, P. Pairattanakorn⁴, W. Nasomsong⁵, S. Khahakaew⁶, C. Brukesawan², S. Traithipsirikul³, P. Tassanaananchai⁴, P. Monkongdee¹, S. Noknoy⁷, N. Chantharojwong¹, S. Northbrook¹, P. Kamolwat⁸, R. Lolekha¹

Institutions

¹Division of Global HIV and Tuberculosis, U.S. Centers for Disease Control and Prevention, Nonthaburi, Thailand, ²Public Health Center 28, Health Department, Bangkok Metropolitan Administration, Bangkok, Thailand, ³Taksin Hospital, Medical Service Department, Bangkok Metropolitan Administration, Bangkok, Thailand, ⁴Klang General Hospital, Medical Service Department, Bangkok Metropolitan Administration, Bangkok, Thailand, ⁵Division of Infectious Diseases, Department of Internal Medicine, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand, ⁶Sirindhorn Hospital, Medical Service Department, Bangkok Metropolitan Administration, Bangkok, Thailand, ⁷Division of AIDS and STIs, Department of Disease Control, Thailand Ministry of Public Health, Nonthaburi, Thailand, ⁸Division of Tuberculosis, Department of Disease Control, Thailand Ministry of Public Health, Nonthaburi, Thailand

BACKGROUND: A 2019 meta-analysis reported that 25% of the global population had latent tuberculosis infection (LTBI). Despite the Thai national HIV guidelines recommending tuberculosis preventive treatment (TPT) in newly diagnosed PLWH with CD4 <200 cells/mm³, those exposed to TB, or those who tested positive for LTBI, only 0.4% of PLWH received TPT in 2019. We assessed the prevalence of LTBI among PLWH in Bangkok using Interferon-Gamma Release Assay (IGRA) to inform policy decisions.
METHODS: Since March 2022, the Thai Ministry of Public Health and PEPFAR Thailand implemented LTBI screening among PLWH using IGRA (T-SPOT.TB) in five hospitals with high HIV burden in Bangkok. Eligible clients included those with documented positive HIV test results, chest X-Ray, and IGRA test results without a history of TPT or TB treatment. Data from Thailand’s HIV/TPT database during March – November 2022 was analyzed using multivariate analysis to identify factors associated with positive IGRA results.
RESULTS: Of 888 PLWH who received IGRA screening, 20.4% (181/888) tested positive. The median age was 38 years; 612 (68.9%) were male, 667 (75.1%) were Thai, and 642 (72.3%) were ART naïve. Of 872 PLWH with CD4 results, about 20% tested positive across all CD4 categories, except those with CD4 <50 cells/mm³, in which 5.6% (1/18) tested positive. Factors associated with positive IGRA results included PLWH in the 30-44 (AOR: 2.06, 95%CI 1.24-3.52) and 45-59 (AOR: 2.44, 95%CI 1.35-4.50) age groups after adjusting for other variables. Nationality, CD4 count, gender, and ART history were not significantly associated with positive IGRA results.

Table 1: Characteristics of PLWH tested with IGRA and factors associated with LTBI, Bangkok, March – November 2022

Characteristic	Overall N = 805¹	IGRA +ve N = 163	Univariate			Multivariate
Characteristic	Overall N = 805¹	IGRA +ve N = 163	OR²	95% CI²	p-value	OR²	95% CI²	p-value
Age group, n (%) 0-29 30-44 45-59 =60	201 (25.0%) 331 (41.1%) 249 (30.9%) 24 (3.0%)	25 (15.3%) 71 (43.6%) 61 (37.4%) 6 (3.7%)	- 1.92 2.28 2.35	Ref. 1.19, 3.20 1.39, 3.86 0.79, 6.21	- 0.010 0.001 0.10	- 2.06 2.44 2.59	Ref. 1.24, 3.52 1.35, 4.50 0.84, 7.22	- 0.006 0.004 0.079
General population³, n (%)	478 (59.4%)	105 (64.4%)	1.31	0.92, 1.87	0.14	1.02	0.67, 1.54	>0.9
CD4 Count at IGRA test, n (%) >350 0-50 51-100 101-200 201-350	563 (69.9%) 18 (2.2%) 18 (2.2%) 52 (6.5%) 154 (19.1%)	120 (73.6%) 1 (0.6%) 4 (2.5%) 11 (6.7%) 27 (16.6%)	- 0.22 1.05 0.99 0.78	Ref. 0.01, 1.07 0.29, 3.00 0.47, 1.92 0.49, 1.23	- 0.14 >0.9 >0.9 0.3	- 0.21 1.17 1.00 0.82	Ref. 0.01, 1.06 0.32, 3.43 0.46, 1.99 0.51, 1.31	- 0.13 0.8 >0.9 0.4
ARV Status, n (%) Naïve Experience	627 (77.9%) 178 (22.1%)	130 (79.8%) 33 (20.2%)	- 0.87	Ref. 0.56, 1.32	- 0.5	- 1.26	Ref. 0.77, 2.05	- 0.4
¹ n (%), ² OR = Odds Ratio, CI = Confidence Interval, ³General Population: PLWH who were not identified as men who have sex with men, transgender persons, people who inject drugs, sex workers, or pregnant women

CONCLUSIONS: High LTBI prevalence was found among higher age groups, and CD4 did not influence IGRA results except those with very low CD4. The feasibility of TPT implementation and cost-effectiveness of using IGRA for LTBI diagnosis in PLWH or provision of TPT to all PLWH requires further exploration.

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