In a significant epidemiologic study carried out from 2009 to 2016, researchers have shed light on the characteristics and diagnostic challenges of head and neck tuberculosis (HNTB) in Texas, USA. The study, published in “Tuberculosis (Edinburgh, Scotland)” with the title ‘An eight-year epidemiologic study of head and neck tuberculosis in Texas, USA’, analyzed 547 HNTB cases reported to the Centers for Disease Control and Prevention’s TB Genotyping Information Management System. The findings provide critical insights that are essential for managing HNTB, an extrapulmonary manifestation of tuberculosis that predominantly involves cervical lymphadenopathy and poses a persistent diagnostic dilemma.

Epidemiology of HNTB: A Closer Look

Head and neck tuberculosis has been recognized as one of the most common extrapulmonary indications of TB, however, it often goes undiagnosed due to its subtler symptoms compared to pulmonary tuberculosis (PTB). The study focused on elucidating the epidemiology of the disease, finding it most prevalent in patients aged 25-44 and slightly more in females, accounting for 52.7%. Remarkably, cervical lymphadenopathy was identified in 96.9% of the cases of HNTB diagnosed.

Patients with HNTB often presented with concurrent pulmonary involvement. In such cases, co-infections with human immunodeficiency virus (HIV), homelessness, excessive alcohol use within the past 12 months, and drug use were observed more frequently. The social determinants of health were markedly evident in these findings, highlighting the need for greater awareness and tailored public health strategies.

Genetic Lineage and Resistance

The genetic makeup of Mycobacterium tuberculosis (M. tuberculosis) is diverse and affects disease presentation and progression. The study highlighted that the Euro-American L4 lineage was the most predominant in exclusively HNTB cases (52.3%), followed by the Indo-Oceanic L1 lineage (21.5%), and the East-Asian L2 lineage (13.1%). This significant detail emphasizes the geographical variation of TB strains and may influence regional treatment strategies.

Alarmingly, the research identified one case of multidrug-resistant TB (MDR-TB), a form of TB that is resistant to the most effective drugs and is notoriously challenging to treat. Though the case was isolated, the existence of drug-resistant TB strains is a global health threat that necessitates continuous surveillance.

Mortality and Outcomes

Within the scope of the study, seven deaths were reported during treatment. While this number may seem small, it underscores the potential severity of HNTB and the importance of early diagnosis and effective treatment. Achieving favorable outcomes for TB patients, especially those with co-infections or social vulnerabilities, remains a critical challenge for health systems.

Contributions to Public Health

The authors of the study emphasize the significance of understanding the epidemiology of HNTB to improve management and patient care. Recognizing the patterns in demographics, social determinants, and strain lineages can inform targeted screening efforts and tailored treatment regimens that can better address patient needs.

The research team, including Qian Xu, Duc T. Nguyen, Andreas E. Albers, Yue Dong, Jianxin Lyu, Qing H. Meng, and Xiaohong Bi, all affiliated with reputable institutions ranging from the Zhejiang Cancer Hospital and Wenzhou Medical University in China to the University of Texas Health Science Center at Houston and Houston Methodist Research Institute, brings a robust and comprehensive analysis of HNTB. Their work stands as a testament to the enduring importance of epidemiologic studies in advancing global health initiatives.

Conclusion

The eight-year epidemiologic study of HNTB in Texas provides an essential understanding of the disease at the population level. Head and neck tuberculosis continues to pose diagnostic and treatment challenges, but through the efforts of dedicated researchers and health professionals and the use of improved data systems like the TB Genotyping Information Management System, strides can be made in disease management and patient outcomes.

Keywords

1. Head and neck tuberculosis Texas
2. TB epidemiology study
3. Cervical lymphadenopathy TB
4. HNTB in USA
5. Mycobacterium tuberculosis lineage

References

1. Xu, Q., Nguyen, D. T., Albers, A. E., Dong, Y., Lyu, J., Meng, Q. H., Bi, X., & Graviss, E. A. (2019). An eight-year epidemiologic study of head and neck tuberculosis in Texas, USA. Tuberculosis (Edinb), 116S, S71–S77. doi: 10.1016/j.tube.2019.04.013
2. World Health Organization. (2020). Tuberculosis. Retrieved from https://www.who.int/tb/en/
3. Centers for Disease Control and Prevention. (2020). Extrapulmonary Tuberculosis. Retrieved from https://www.cdc.gov/tb/topic/disease/extrapulmonary.htm
4. Pai, M., Behr, M. A., Dowdy, D., Dheda, K., Divangahi, M., Boehme, C. C., … & Zwerling, A. (2016). Tuberculosis. Nature Reviews Disease Primers, 2, 16076. doi: 10.1038/nrdp.2016.76
5. Comas, I., Coscolla, M., Luo, T., Borrell, S., Holt, K. E., Kato-Maeda, M., … & Gagneux, S. (2013). Out-of-Africa migration and Neolithic coexpansion of Mycobacterium tuberculosis with modern humans. Nature genetics, 45(10), 1176–1182. doi: 10.1038/ng.2744

DOI of the mentioned article: 10.1016/j.tube.2019.04.013