In the United States, a case of tuberculosis in a young child is a rarity – so rare that while the majority of the world vaccinates its children against more severe forms of tuberculosis with Bacillus Calmette-Guérin (BCG) vaccine, experts in the US have weighed the risks and benefits of this vaccine and determined this should not be on our recommended schedule. However, there are rare circumstances when we should remember that we have the BCG vaccine, and it may yet find clinical utility.
This past winter, a 6-month-old presented with seizures and stroke and was found to have tuberculosis meningitis. Her mother had been born in Vietnam, had lived in the US for a time, but had traveled back to Vietnam prior to pregnancy and traveled through the country while pregnant. Upon return, her mother received routine prenatal care, delivered the infant and then proceeded to exhibit a cough for which she received various antibiotics. Eventually, the mother received a chest radiograph when the infant was 5 months old.
Her chest X-ray showed a cavitary lesion, but because of miscommunication due to a language barrier, she never received additional workup or treatment. One month later, her daughter presented to an emergency room.
Where could our system have acted differently? Unfortunately, the delay in the mother’s diagnosis was the most detrimental point of this case. The missed diagnosis falls with adult physicians, but we also have the responsibility to be aware of risks for new infants. However, had the mother been identified earlier as having tuberculosis instead of bacterial pneumonia, there are recommendations for the newborn.
If a mother or household contact exhibits clinical signs and symptoms or abnormal chest radiograph consistent with tuberculosis, the infant and mother should be separated until the mother has started appropriate therapy, and the mother should also wear a mask. The infant should begin isoniazid, and separation should continue after that only if there is concern for multidrug-resistant TB. BCG immunization should be considered for the infant, as long as the child is not HIV-infected.
BCG vaccine is a live vaccine originally prepared from attenuated strains of M. bovis. It is used in more than 100 countries to reduce the incidence of disseminated TB and other life threatening manifestations of tuberculosis in infants and young children. It has relatively high efficacy again miliary and meningeal tuberculosis.
Circumstances in which BCG is recommended include:
- Continuous exposure to a person with contagious pulmonary tuberculosis resistant to isoniazid and rifampin and cannot be removed from this exposure
- Continuous exposure to a person with untreated or ineffectively treated contagious pulmonary tuberculosis
In this case, the mother likely obtained her infection from Vietnam, which has high isoniazid resistance, and was the sole caregiver of the infant as her husband remained behind in Vietnam. Had we recognized an infant at risk and administered the vaccine, was this case preventable?