Editorial commentary: Contact tracing in children exposed to an index case of tuberculosis: the need, the challenge, and the impact

The impact of screening for tuberculosis exposure in the household in children with tuberculosis disease: A difficult riddle to solve

BACKGROUND

Tuberculosis (TB) infection is transmitted by sharing the same airway with people with active TB. Children are often not considered the source of TB bacilli, and index case investigation is carried out after diagnosis. Here, we describe the impact of the presence of a household index case on childhood TB disease.

METHODS

The data of patients aged between 1 month and 18 years who were diagnosed with TB were collected. We compared patients according to whether they had an index case in the household or not.

RESULTS

A total of 202 TB patients were enrolled, of whom 62 (30.7%) had a household index case. There was no significant difference in having a household index case between TB patients under the age of five (23.3%) and older children (33.8%) (p = .140). Pulmonary TB was present in 61.4% of the cases, and extrapulmonary TB was present in 38.6% of the cases. The rate of patients who had a household index case was significantly higher in pulmonary TB (46.8%) compared to extrapulmonary TB (5.1%) (p < .001). Pulmonary TB patients with a history of household contact were more likely to have diagnostic radiological findings (93.1%) compared to those without (75.8%) (p = .009). However, pulmonary TB patients without household contact history had a higher rate of diagnostic microbiological findings (59.1%) and constitutional symptoms (63.6%) (p = .019 and p = .013, respectively).

CONCLUSION

Household contact research is an important epidemiological tool. However, considering the contact rates in the household, new and more comprehensive public health programs are required to prevent the spread of childhood tuberculosis.

Evaluation of TB Case Finding through Systematic Contact Investigation, Chhattisgarh, India

Rationale. Contact investigation is an established tool for early case detection of tuberculosis (TB). In India, contact investigation is not often conducted, despite national policy, and the yield of contact investigation is not well described. Objective. To determine the yield of evaluating household contacts of sputum smear-positive TB cases in Rajnandgaon district, Chhattisgarh, India. Methods. Among 14 public health care facilities with sputum smear microscopy services, home visits were conducted to identify household contacts of all registered sputum smear-positive TB cases. We used a standardized protocol to screen for clinical symptoms suggestive of active TB with additional referral for chest radiograph and sputa collection. Results. From December 2010 to May 2011, 1,556 household contacts of 312 sputum smear-positive TB cases were identified, of which 148 (9.5%) were symptomatic. Among these, 109 (73.6%) were evaluated by sputum examination resulting in 11 cases (10.1%) of sputum smear-positive TB and 4 cases (3.6%) of smear-negative TB. Household visits contributed additional 63% TB cases compared to passive case detection alone. Conclusion. A standard procedure for conducting household contact investigation identified additional TB cases in the community and offered an opportunity to initiate isoniazid chemoprophylaxis among children.