A 20-year retrospective cohort study of TB infection among the Hill-tribe HIV/AIDS populations, Thailand

A retrospective cohort study was conducted to determine the situation, trend, and factors associated with TB infection, and factors related to the life status among the HIV/AIDS Hill-tribe in Northern Thailand. Hill-tribe people have been migrating to and formed settlements along the Thai border areas for many decades. There are now having 1.6 million people of 6 different groups–Akha, Lahu, Lisu, Hmong, Yao and Keren–each with a specific culture, language and lifestyle. The Hill-tribe becomes a new vulnerable of HIV and TB infections in Thailand.

A systematic data-reviewing approach was used to identify the information from the rosters of ARV clinics, OPD cards, and laboratory reports from 16 hospitals in Chiang Rai Province, Thailand. The data were collected from the first reported HIV/AIDS case of the Hill-tribe to the end of 2010. A chi-square test and logistic regression models were used to identify associations at the significance level of alpha = 0.05.

A total of 3,130 cases were included in the study. The majority of patients were Akha (46.0 %) followed by Lahu (19.7 %), 54.6 % were males, 44.6 % were 26–35 years old. The major risk factor of HIV infection was sexual intercourse (93.1 %); 23.9 % were still alive at the date of data collection, 30.7 % were diagnosed with pulmonary TB. The Akha Hill-tribe HIV/AIDS individuals had a greater chance of TB infection than did Yao individuals with OR_adj = 1.50 (95 % CI = 1.01-1.92). Females had a greater chance of TB infection than males with OR_adj = 1.33 (95 % CI = 1.11-1.59); being classified as HIV and AIDS groups had a greater chance of TB infection than those asymptomatic group with OR_adj = 11.59 (95 % CI = 7.19-18.71), and OR_adj = 1.71 (95 % CI = 1.03-2.87); and not having received the ARV group had a greater chance of TB infection than those who having received the ARV group with OR_adj = 2.59 (95 % CI = 2.09-3.22). The patients who had been diagnosed with HIV infection during 1990–1995 and 1996–2000 had less chance of TB infection than those who were diagnosed from 2006–2010, with OR_adj = 0.04 (95 % CI = 0.01-0.14) and 0.11 (95 % CI = 0.07-0.17), respectively. Regarding life status; females had a better chance of being still alive at the date of data collection than being males with OR_adj = 1.41 (95 % CI = 1.19-1.66). Those who had a defined route of transmission in the category of “mother-to-child” and “IDU” had a better chance of being still alive compared to those who contracted HIV from “sexual intercourse,” with OR_adj = 2.05 (95 % CI = 1.56-2.18), and OR_adj = 8.45 (95 % CI = 1.55-46.13), respectively.

Thailand needs to create a TB and HIV/AIDS surveillance system for Hill-tribe populations to determine the situation and trend and to develop an appropriate model for providing care at the earlier stage of HIV/AIDS infection to prevent later TB infection.