It’s not very easy to know if a newborn infant got infected by tuberculosis from his mother (ie congenital) or acquired it after birth.
Whatever may be the cause strong suspicion should be there if the mother has tuberculosis.To diagnose if the baby has tuberculosis or not first thorough clinical examination should be done. Appropriate lab 🔬 tests may also be required to achieve diagnosis. Documentation of bacteria (acid fast bacillus) in sputum or other body fluids can be definitive towards a diagnosis of tuberculosis.
Chest xray can also be supportive in diagnosis of tuberculosis.
When lab based definitive prove of tuberculosis is not available, prophylactic use of isoniazid may be a wise thing to do. Following this a Montoux test can be done and if the test is negative BCG vaccination can be done to ensure better protection from koch’s. But in cases where the test is positive isoniazid may be continued for few more months.
However, in cases where definitive evidence of tuberculosis is there as supported by lab tests like sputum AFB and chest xray, a full course of anti-tuberculosis therapy may prove beneficial.
All koch’s contacts should be treated too.