The World Health Organization has stated that the previous practice of separating the sick mother from the baby is no longer recommended as this made breastfeeding and care of the baby by the natural mother impossible. This also increased the baby's chances of getting sick or malnourished due to artificial feeding.
Clearly, tuberculosis is not a contraindication to breastfeeding. In fact, if you review this WHO chart on management of maternal tuberculosis and breastfeeding, you can see that in all instances - regardless of when the TB was diagnosed or being treated, the mother should breastfeed.
Further, mothers who are given anti-TB medicines CAN continue to breastfeed their babies. Read this from the CDC:
Breastfeeding should not be discouraged for women being treated with the first-line antituberculosis drugs because the concentrations of these drugs in breast milk are too small to produce toxicity in the nursing newborn. For the same reason, drugs in breast milk are not an effective treatment for TB disease or LTBI in a nursing infant. Breastfeeding women taking INH should also take pyridoxine (vitamin B6) supplementation.Now you ask, what about the women who are not being treated? I throw the question back to you -- why are they not being treated? Most likely, these women do not get treatment simply because they cannot afford it. If they cannot afford the medicines for tuberculosis, do you think they can afford to purchase formula milk and its implements for their babies? Will they have access to clean water? Will they have access to health centers where they can bring their babies who may get sick due to artificial cleaning?
Chances are, the best way for the babies of these untreated mothers with TB would be to continue to breastfeed. Thus, tuberculosis is not a contraindication for breastfeeding.