When Conventional Drugs Aren’t Enough: Enhancing the Immune System in Pulmonary Infections
Dr Keertan Dheda’s presentation at the American Thoratic Society 2013 International Conference, “XDR TB: What Else Can We Do?” focused on the growing epidemic of drug resistant tuberculosis (DR TB). Dr Dheda said there are about 25000 XDR TB global cases annually, and that DR TB can be “very expensive to treat and manage.” Despite several drug regimen variations, there is evidence that truly effective DR TB treatments may take decades to be formulated. Dr Dheda further commented that poor adherence to drug regimens can partly predict resistance in TB patients. Future studies may have to contemplate treatment alternatives. “The immunology of DR-TB is poorly studied,” Dr Dheda said, “and given success in other chronic diseases and the lack of effective drugs, immunomodulatory strategies deserve further investigation.”
Dr Kevin Fennelly, MD, MPH, followed Dr Dheda as he discussed prevention as the key in controlling TB transmission. His presentation, “Preventing Transmission: Attacking TB Outside the Host,” asserted prevention starts by focusing on the TB infected patient. Because TB is spread by aerosols, and not sputum, healthcare providers should be especially vigilant in removing the infected patient from the environment to prevent exposing uninfected people. In some cases, patients who wore a surgical mask decreased TB transmission by 56%; Dr Fennelly suggests this data may provide evidence for more efficient prevention in transmission of TB to care givers.
While technology varies on TB patient care internationally, sometimes there are traditional treatments that work despite cost restrictions. For instance, Ugandan clinics often use open ventilation in large patient rooms because they do not have the resources for individual isolation rooms. Often individual isolation is more common in American hospitals.
Dr Fennelly further suggests that it is environmental controls that will greatly help prevention of spreading the disease. At the patient level, they should be given cough monitors, be put on therapy as quickly as possible, and separated from other susceptible patients. For treatment options, he suggests there should be studies around aerosol collection, and inhaled antibiotics. At the environmental level, it’s critical to optimize dilution ventilation, keep patients outdoors when possible, and minimize crowding if separate rooms are not available. For example, Dr Fennelly noted one study in Milan showed that the clinic was able to control outbreaks just by moving patients to isolation. Finally, at the healthcare worker level, education is key. Dr Fennelly felt it was important to teach those care providers with immunsopressant diseases, like diabetes or HIV, to keep away from infected TB patients. In addition, it is worthwhile for healthcare providers to consider more simple factors in treatment, such as a patient’s nutrition and sleep pattern.
Overall, issues related to preventing transmission of tuberculosis, as well as the treatment of afflicted patients, will be a continuing field of study. While some drug regimens contribute to effective TB management, sometimes the more traditional methods like ventilation or surgical mask use can be just as beneficial to transmission control.