Tuberculosis among pregnant women in Ethiopia independently correlated with HIV infection and increasing age, which suggests that young women in the country are continuously exposed to, and infected with, contagious TB, according to findings in Clinical Infectious Diseases.
“TB is the leading cause of death from any single infectious agent, accounting for 1.45 million deaths in 2018. While the global incidence of TB seems to slowly decline, the current pace is insufficient to reach the 90% reduction by 2035 set up in the WHO End TB strategy,” John Walles, a doctoral student in the department of translational medicine at Lund University and the department of infectious diseases at Central Hospital in Kristianstad, Sweden, told Healio. “In Ethiopia, around one-third of active TB cases go unrecognized, driving the epidemic. Optimization of case-finding strategies for active TB in endemic countries may be required. Improved understanding of exposure patterns in endemic, resource-limited settings is important to target such interventions.”
Walles and colleagues examined data from pregnant women seeking antenatal care at public health facilities to determine if immunomodulation, which occurs in pregnancy, could interrupt the immune control of latent TB infection. The researchers performed structured interviews, a physical examination and QuantiFERON-TB Gold-Plus (QFT) testing on all participants. Additionally, they examined all women with symptoms consistent with TB and all women with HIV for active TB using sputum bacteriological testing. Walles and colleagues looked for relationships between TB infection and clinical, demographic and socioeconomic characteristics.
In total, 1,834 participants were involved in the study. Of those, 679 (37%) met the criteria for TB, including 80 (4.4%) with previously active TB, five (0.3%) with currently active TB and 594 (32.4%) who were QFT-positive no previously or currently active TB. The five women with active TB were diagnosed during pregnancy, according to Walles.
Age (annual adjusted OR = 1.069; 95% CI, 1.045-1.093) and HIV infection (aOR = 1.43; 95% CI, 1.033-1.998) independently correlated with being positive for TB, although researchers noted that the relationship with increasing age was seen only in HIV-negative women and translated to an estimated annual risk for TB infection of 2.1% in HIV-negative women. TB correlated with HIV infection, but there was no relationship between increasing age and TB infection in women who were HIV-positive, according to Walles. He noted that “the excess of TB infection in this group” could be explained by previously and currently active TB.
“These findings suggest the presence of contagious TB where these women live and indicate continuous exposure in this vulnerable population,” Walles said. “Increased efforts to diagnose and treat people with unrecognized active TB should be prioritized in order to curb the TB epidemic in Ethiopia and sub-Saharan Africa.”
Walles J, et al. Clin Infect Dis. 2020; doi:10.1093/cid/ciaa561.
Disclosure: The authors report no relevant financial disclosures.