Drug-resistant TB (DR-TB) in children is a special epidemiological, clinical, and diagnostic problem, and its global incidence remains unknown. DR-TB in children is usually of a primary nature and is most often transmitted to the child from a household contact, so these cases reflect the prevalence of DR-TB in the population of adult patients. The risk of infection with Mycobacterium tuberculosis complex (MTBC) in children depends on age, duration of exposure, proximity of contact with the infected person, and the level of source virulence. Most cases of TB in children, especially in infants, are caused by household contacts, where the main sources of infection are parents, grandparents or older siblings. However, there are many documented cases of TB transmission outside the family. The most common source of infection is an adult who is profusely positive for mycobacteria, diagnosed too late, and inadequately treated. It has been estimated that a sputum-positive patient might infect 30-50% of their household members. For this reason, active epidemiological investigation and contact tracing in the environment of sputum-positive patients are the most appropriate methods of identifying infected family members. This paper presents a case report concerning the transmission of extensively drug-resistant TB, Beijing 265 genotype, from a mother to her 10-month-old daughter. It is the first case diagnosed in Poland, and one of very few described in the literature where treatment was effective in the mother and the infant recovered spontaneously.
Keywords: Mycobacterium tuberculosis; XDR-tuberculosis; drug resistance; household TB transmission.