Cases of tuberculosis (TB), an airborne bacterial disease, in the US have been steadily decreasing, thanks to improved socioeconomic conditions, focused screening efforts, and thorough follow-up. 9,272 TB cases were found in the US in 2016, down from about 21,210 cases in 1996 [1]. Pediatric TB cases have also been on the decline. In 2016, about 4% of the TB cases were pediatric. However, data from the past several years shows the incident caseload has remained steady [2].
What are contributing reasons for the leveling of pediatric TB cases? Contributing factors to difficulty in controlling and managing pediatric TB cases are that TB symptoms are nonspecific, there is inadequate sputum for diagnosis, and there are culture-negative TB cases. A quarter of cases are extrapulmonary TB cases, presenting further diagnostic challenges. Another challenge to addressing TB is that risk-factors in children are different than adults. On the contrary to adult TB, about 90% of the pediatric TB cases are in US-born children, indicative of recent transmission of TB [3]. The primary source for TB among children is exposure to TB in households. This makes active case screening difficult, as it can come across as invasive to screen for TB in children.
A possible contributing factor is the different knowledge base of how to address TB among providers, especially in areas where TB is not as prevalent. A study examining the number of consultations about TB among five CDC-run Regional TB Training and Medical Consultation Centers suggests decreased nurse and physician knowledge about TB diagnosis and management over the years. ~20% of the consultations were for pediatric TB, which is a disproportionate number given that only 4% of cases in the US are pediatric [4]. The decreased knowledge base is likely due to the disproportionate epidemiology of TB cases in the US. Over 50% of cases of TB are found in four states (Texas, Florida, California, New York), but TB is found in all fifty states [5]. The skewed epidemiology, with TB cases concentrated in four states, lends itself to a disproportionate knowledge base among providers.
Without renewed push to address TB, eradication of the disease in this century will not be achieved. However, contrary to what is needed, the US has proposed decreased funding for global TB efforts in the amount of $181 million in FY2019, down from $264 million in FY 2018 [6]. Worldwide, 233,000 children died from TB in 2017 [7]. More concerning is that 67 million children are estimated to have latent TB, indicating they could develop TB in the future [8]. Given that the US has the technical capacity, the knowledge, and the resources to address TB, the US has a crucial chance to make a difference in the fight and should take a lead role.
Ye jin Kang, MD MPP
[1] https://www.cdc.gov/tb/statistics/tbcases.htm
[2] https://www.cdc.gov/tb/publications/slidesets/pediatrictb/PediatricTB_SlideSet2_Notes_2016.pdf
[3] http://pediatrics.aappublications.org/content/133/3/e494
[4] https://www.sciencedirect.com/science/article/pii/S2405579417300712]
[5]https://www.cdc.gov/tb/publications/factsheets/statistics/tbtrends.htm
[7] http://www.who.int/tb/areas-of-work/children/en/.
[8] http://www.who.int/tb/challenges/childhood_tb_informationsheet.pdf