Tuberculosis remains a significant global health threat, with progress in controlling the disease disrupted by the COVID-19 pandemic. In 2021, tuberculosis claimed 10.6 million lives, with over 1.6 million people falling ill.
The distribution of tuberculosis is uneven, with 90% of cases found in 30 low- and middle-income countries. The reasons for this uneven spread are not fully understood but are thought to be influenced by a complex mix of factors. It includes the interaction between infected and susceptible individuals, the characteristics of the bacteria that cause tuberculosis, the physical environment, and broader socioeconomic factors like poverty.
According to the Ministry of Health, Vietnam ranks 16th out of 30 countries for drug-susceptible tuberculosis cases, and 13th globally for the highest burden of multidrug-resistant tuberculosis. A deeper understanding of the factors influencing tuberculosis and multidrug-resistant tuberculosis is crucial for disease control.
The OUCRU study examined tuberculosis patients treated at state-owned hospitals in 23 Ho Chi Minh City districts from January 2020 to April 2023. The researchers used individual-level data to describe the city’s tuberculosis burden and case characteristics. They also used district-specific data to identify factors associated with the disease at the district level.
Analysis from January 2020 to April 2023 revealed 36,089 people registered for drug-susceptible tuberculosis treatment in Ho Chi Minh City, with 1,451 cases of multidrug-resistant tuberculosis (excluding cases involving people living outside the city).
Most cases were male (67.7%) and lived in urban areas (81%). The average age was 45. About 5% also had HIV. Nearly 32,000 cases never had tuberculosis before, while 5,516 had a history of the disease. Among those getting multidrug-resistant tuberculosis treatment, 2% got tuberculosis for the first time, and 14% had had tuberculosis in the past.
Most drug-susceptible and multidrug-resistant tuberculosis cases occurred in middle-aged men, and the burden increased with age. This is consistent with the results of Vietnam’s second national tuberculosis prevalence survey and other studies.
The study identified central Ho Chi Minh City as a hotspot for both drug-susceptible and multidrug-resistant tuberculosis, while the northern area witnessed notably lower cases.
The number of tuberculosis cases varied greatly across districts for both types. Drug-susceptible tuberculosis cases were mainly concentrated in central districts, with prevalence rates varying in the surrounding areas. In contrast, multidrug-resistant cases tended to cluster in areas with already high tuberculosis cases, indicating a more consistent distributing pattern.
Differences between men and women in both types of tuberculosis show how biology, behaviour, and the environment all play a role. There is a strong possible link between HIV levels and tuberculosis cases, even in areas with relatively low HIV rates.
The study found that the estimated rate of both drug-susceptible and multidrug-resistant tuberculosis in Ho Chi Minh City was much lower than the WHO’s estimate for Vietnam. This was surprising because Ho Chi Minh City is known for having high tuberculosis rates in Vietnam. This is likely due to underreporting of tuberculosis, as many people with tuberculosis may be undiagnosed.
Moreover, the study showed that estimates of poverty within districts were not significantly linked to the rates of tuberculosis. Instead, gender and HIV prevalence were more closely linked to the disease burden.
Read the full paper on the Emerging Infectious Diseases website: https://wwwnc.cdc.gov/eid/article/30/3/23-1309_article.