The PD Hinduja hospital detected four people with total drug resistant (TDR) tuberculosis (TB), the first such cases in the country till November last year. In the last two months, eight others have been detected with TDR-TB...Further details about these cases in India here (and probably elsewhere).
Till November 2011, the hospital got four TB patients resistant to all first-line (Isoniazid, Rifampicin, Ethambutol, Pyrazinamide and Streptomycin) and second-line (Ofloxacin, Moxifloxacin, Kanamycin, Amikacin, Capreomycin, Para-aminosalicylic acid and Ethionamide) drugs.
“After thoroughly checking their prescriptions, we found that three of them had received erratic and unsupervised second-line drugs. They were often given in incorrect doses by multiple private practitioners to cure their multi-drug resistant (MDR) TB,” Dr Udwadia said. “The mortality rate of MDR, XDR and TDR-TB is 30%, 60% and 100% respectively.”
08 January 2012
Totally drug-resistant tuberculosis
Not multi-drug-resistant (MDR) TB, but TOTALLY drug resistant:
I was recently talking to my sister who studies economics and biomedical science about the mechanics of drug-resistent bacteria. It turns out that ANY bacerial colony will ALWAYS have a certain number that are drug-resistent. Under normal circumstances this number is kept in check by having to compete for nutrients with the substantially higher numbers of vulnerable bacteria, and when the antibiotics hit, the small number of resistent bacteria remaining can be easily cleaned up by the immune system.
ReplyDeleteHowever, when patients eratically take antibiotics or don't complete their courses, the numbers of competing bacteria are reduced, but not enough so that the immune system can eradicate the infection all by itself. Thus the resistent bacteria have less competition and are left to thrive, resulting in infections that are virtually incombatible with antibiotics.
According to the agent-based model my sister made, drug-resistent bacteria do best when patients take their antibiotics about 80% of the time: any less, and there are too many non-resistent bacteria for the resistent ones to take hold; any more, and the infection is reduced to the point where the immune system can handle it.
Right, but the fault does not lie just with patients for erratically taking meds. It also lies with physicians or other health providers who give patients inappropriate regimens of drugs (giving them 3 drugs for TB when the patient's organism is resistant to 2 of the drugs, thus effectively leaving them on one drug) and on criminals who manufacture fake drugs, so that when it seems that the patient is on multiple effective drugs, they really are not.
ReplyDeleteEffective treatment of tuberculosis is a major test of the entire public health service, rather than merely a task of a physician.