suspected congenital tuberculosis is a tough one; is the mother on TB treatment?
a) What did the baby's CXR reveal (although congenital TB can present with no CXR findings initially, it will still be worth checking)
mantoux interpretation and TB interferon gamma assay (TB Elispot) aalso difficult to interpret in endemic environment and considering age; nevertheless a positive result would indicate infection at least and with symptomatology you would be obliged to treat as Tb disease
In my experience, with suspected maternal TB in an endemic setting for TB, and a baby symptomatic for a chronic infection, we have offered a course of TB treatment.
Will also be worth checking CMV status