Click here to view next page of this article TuberculosisThe first discussion will be on tuberculosis. Tuberculosis is one of the most common diseases in the world, but what has occurred in the United States has been a steady decline in the amount of cases that we were seeing until 1984 tuberculosis, TB. In 1984, we reached a nadir of about 22,000. This was the time that the public health services came out with their recommendations to eliminate tuberculosis. There are a lot of factors involved in the resurgence of tuberculosis. One the principal factors was the HIV epidemic and there is certainly a much higher incidence of tuberculosis in those individuals who are infected with tuberculosis. Also, because tuberculosis was becoming less of a prevalent disease, a lot of the federal funding for public health problems for completion of therapy in those individuals who were infected was decreasing, so less money was available and people were not as compliant with their treatment protocols. Other factors included increased immigration, increased individuals who lacked medical insurance, substance abuse problems, all of that resulted in this peak and rise in tuberculosis. In terms of diagnosis, the tuberculin skin test will be reviewed in detail in a little bit. For establishing the diagnosis of tuberculosis, it is not that helpful. The tuberculin skin test can indicate the presence, but does not necessarily tell you that the person has active disease. It is important to remember that twenty percent of individuals with active tuberculosis will not have a positive tuberculin skin test. They are usually very malnourished and if you went back and tested those individuals, probably in two or three weeks. In terms of treatment, these are the first-line agents that are available; they are all bactericidal drugs: isoniazid, rifampin, ethambutol, pyrazinamide and streptomycin. The principal things that we must do when we treat tuberculosis is what we must use combination therapy. When you have millions upon millions of mycobacteria in a cavity, there is going to be some population which may have mutations which confer resistance to some of the antibiotics that you are using. The problem with tuberculosis is that you need to treat it for a very long time. The shortest regimens are six months and frequently, everybody feels better after taking medications for a month and then they stop taking their medications and then relapse with their disease. It is really essential that we monitor compliance. Most of the public health problems recommend doing directly observed therapy. Directly observed therapy is where we actually watch the patient take their medications. In Philadelphia, they have case workers who go out to the patient's house and deliver the medications to the patient. Here are some of the resistance patterns in the United States. In the early 1990's, the CDC had stopped doing surveillance for tuberculosis resistance in the United States and then with this resurgence, they restarted it again because some of the outbreaks that were occurring were in individuals who had multidrug-resistant tuberculosis. This is from 1993 to 2006, looking at the susceptibility pattern of the isolates in the United States. You can see that eight percent of them were INH resistant, rifampin resistance was three percent and INH and rifampin, which is defined as multidrug-resistance, was two percent. Essentially, INH resistance was greater than four percent and this is really found throughout the lower United States. |