A retrospective study by a Delhi hospital of over 77,000 patients admitted to it between 2000-2009 has found a rise in antibiotic resistance by 40-97 per cent with increased prescription of drugs.
Senior officials of the Indian Council for Medical Research (ICMR) said that it was the largest analysis of data on drug resistance from a single Indian hospital,spread over the longest period (10 years).
The study by Sir Ganga Ram Hospital has been published in the the latest issue of the ICMRs monthly paper,Indian Journal of Medical Research.
The authors reported an alarming increase in resistance and antibiotic use over the years in patients admitted to the hospital. While the total antibiotic consumption among patients did not change substantially during the period,there was a significant increase in prescription of broad-spectrum antibiotics.
For these high-end,last resort antibiotics,used for multi-drug-resistant diseases,resistance was seen to increase dramatically.
In case of carbapenems (the most commonly used broad-spectrum antibiotics),the jump was from 2.4 per cent in 2002,when they were first introduced at the hospital,to 52 per cent in 2009 in case of drugs given against bacterium Klebsiella pneumoniae. For cefotaxime used against K pneumoniae,resistance increased from 75 to 97 per cent,and in the combination of piperacillin-tazobactum,a jump from 55-84 per cent was observed.
According to Dr Chand Wattal,Head of Microbiology at the hospital,and the corresponding author of the study,We have been analysing the epidemiological resistance patterns in bacteria in our hospital,and this is our cumulative analysis for the two most common bacteria.
Doctors screened blood samples for enzymes released by two common kinds of bacteria Escherichia coli (E coli) & Klebsiella pneumoniae. The presence of these enzymes in the blood indicates that the bacteria have become resistant to antibiotics. Of 77,618 blood samples screened,13,153 were culture positive. Enzyme released by K pneumoniae was found in 1,271 samples,and 1,103 had E coli.
The data on monthly antibiotics issued to patients was accessed from hospital records. From 2000 to 2009,despite the requisite dose of antibiotics being administered to patients,the detection rates of both bacteria in blood samples increased from 2.59 to 17.6 per cent.
High isolation or detection rate,in spite of medication,indicates that the microbe is resistant to the antibiotic, Dr Wattal said. Till 2006,E coli was more resistant,being the dominant microbe in blood samples,after which resistance of K pneumoniae increased.
Doctors were also able to establish a direct co-relation between introduction of antibiotics and the resistance developed by the bacteria against them. As the study states,Tigecycline was introduced in the hospital formulary from 2007 and in the same year a resistance of 14 per cent was observed,which further increased to 20 per cent in 2009 in K pneumoniae.
In 2009,after the broad-spectrum categories were introduced,resistance was seen in 50 per cent of the samples of both bacteria.
According to Dr Wattal,There is an urgent need to detect drug-resistant isolates at an early stage,so we can plan treatment better. Since increase in prescriptions was seen to be associated with resistance,it is crucial that the drugs are prescribed judiciously.