Extrapulmonary tuberculosis among children: peculiarities of age’s groups and drug resistance of mycobacterium tuberculosis

Objective — to analyze the peculiarities of detection and course of various clinical forms of extrapulmo­nary tuberculosis (EPTB), the profile of drug resistance of the Mycobacterium tuberculosis (MBT) among children of different ages. 
Materials and methods. We retrospectively analyzed the medical data of 47 children aged 0 to 14 with local forms of EPTB, hospitalized in the pediatric department of Lviv TB hospital from 2013 to 2020. Children were divided into groups: up to 1-year-olds (19 children; group I), 2—9 year-olds (19 children; group II) and 10—14-year-olds (9 children; group III). 
Results and discussion. It was found that children under 1 year of age were more likely to live in rural areas than in urban areas (78.9 vs. 21.1 %; p < 0.01). Resistant forms were diagnosed among 49.0 % of children. Among children of the first year of age this number reached 73.7 %, which is probably more often than among children aged 2—9 (26.3 %; p < 0.01). The numbers of multidrug-resistant TB (MDR-TB) and the risk of MDR-TB among children under one year of age were 35.7 and 28.6 %, respectively. The most common clinical form of EPTB was TB of peripheral lymph node (PLN) regardless of age (40.4 %). Only TB of PLN and TB of meningeal and CNS were found among children under 1 year of age. Among children aged 2—9, TB of PLN and TB of bone and joints were probably more common than all other localizations. TB of bones and joints among children aged 10—14 was more common than TB of eyes and skin. The proportion of TB of meninges and CNS in group I was probably higher compared to groups II and III (p1 < 0.01; p2 < 0.05). At the same time, TB of bones and joints among children of groups II and III was diagnosed significantly more often than in group I (p1 < 0.01; p2 < 0.05).In 89.4 % of cases EPTB was combined with pulmonary TB (PTB). Among children under one year of age, miliary PTB was diagnosed probably more often than other clinical forms (p < 0.05). Bilateral lesions were probably more common among children under one year of age than in children aged 10—14 (77.8 vs. 28.6 %; p < 0.05). Unilateral lesions were more common among children aged 10—14 than in children up to one year of age (22.2 vs. 71.4 %; p < 0.05). Children under 1 year of age and 2—9-year-olds were significantly more likely to be diagnosed with EPTB when seeking medical care than during examination of contact persons (63.2 vs. 26.3 %; 68.4 vs. 31.6 %; all p < 0.05) and during the preventive examination (10.5 % and 0; all p < 0.01). Also, EPTB was found more often among children aged 10—14 (66.7 vs. 0; p < 0.01). It was found that only 36.8 % of children of group I, 42.1 % of children of group II and 33.3 % of children of group III were sent to a specialized hospital after visiting the clinic.Patients under 1 year of age and 2—9-year-olds compared with children aged 10—14 were significantly more likely to have a combination of clinical manifestations of intoxication and bronchopulmonary syndromes (47.4 and 31.6 % vs. 0; p1 < 0.05; p2 < 0.01). At the same time, intoxication syndrome was significantly more common among children aged 10—14 than among children under one year of age (88.9 vs. 26.3 %; p < 0.01). Lack of vaccination was significantly more common among children under one year of age than in the following age groups (94.7 vs. 57.9 and 44.4 %; both p < 0.05), and the proportion of ineffective vaccinations was significantly higher among children aged 10—14 than in children under 1 year of age (55.6 vs. 5.3 %; p < 0.05). 
Conclusions. These data indicate the need to intensify preventive TB measures among children of different ages, as well as the need for enhanced control over vaccination, regular screening, monitoring of contacts among the adult population and their controlled treatment.