New Delhi: India has witnessed an alarming increase in Drug-resistant pulmonary tuberculosis (DR-TB) in the past two decades, a study published in Bio-Med Central (BMC) Public Health journal revealed.
The study found that over 40% of 45,076 patients, in 75 selected studies for review, suspected for resistance to any first-line anti-TB drugs, tested positive in the last 20 years. Comparative analysis of the studies revealed a worsening trend in DR-TB between the two study decades. It was found to be 37.7% between 1995 and 2005 and 46.1% between 2006 and 2015.
A systematic review of published studies reporting prevalence of DR-TB from biomedical databases (PubMed and IndMed) was conducted. Meta-analysis was performed on DR-TB, multidrug resistant (MDR-) TB, pre-extensively drug-resistant (pre-XDR) TB and XDR-TB were calculated across two study periods i.e. from 1995 to 2005 and from 2006 to 2015, countrywide and in different regions.
The estimate of MDR-TB resistance was higher in previously treated patients with 29.8% from 1995 to 2005 and 35.8% between 2006 and 2015 as compared with the newly diagnosed cases (4.1% between 1995 and 2005 and 5.6% between 2006 and 2015), the study done by Janssen India, Johnson & Johnson Pvt Ltd found.
When it came to regions reporting drug resistant TB cases, overall, studies from Western states of India reported the highest prevalence of DR-TB i.e. 57.8% and MDR-TB i.e. 39.9% during 2006 and 2015. Prevalence of pre-XDR TB was 7.9% with resistance to fluoroquinolone (66.3%) being the highest and the prevalence of XDR-TB was 1.9% over the 20-year period.
“West India had the lowest prevalence of DR-TB during 1995 and 2005 which increased considerably, making it the region with the highest number of DR-TB cases in the 2006 to 2015 decade. The prevalence of MDR-TB in this region also increased between the two decades and the prevalence of primary MDR-TB in newly diagnosed smear-positive patients was higher in this region," the study said.
The 12 studies from West of India included metropolitan cities such as Mumbai, Pune and major cities from Gujarat, highlighting the rapid emergence of DR- and MDR-TB in over-populated urban locales.
“Increased risk of infection transmission due to crowding, inadequacies in community TB control programs and most importantly, the high variability in the anti-TB treatment regimens prescribed by doctors, particularly in the private sector are some potential factors attributable to this upsurge," the study said.
Interestingly, the estimates for MDR-TB from this study are higher than the national estimates reported by the Indian Revised National Tuberculosis Control Program (RNTCP) for the year 2015 (15%, previously treated cases; 2.2%, newly diagnosed cases) and World Health Organization (WHO) estimates for India (16%, previously treated cases; 2.5%, newly diagnosed cases).
“DR-TB is a significant public health issue that considerably deters the ongoing TB control efforts in India. The alarming increase in the trend of anti-TB drug resistance in India warrants the need for a structured nationwide surveillance to assist the National TB Control Program in strengthening treatment strategies for improved outcomes," the study stated.