A nationwide study across 47 hospitals has found that many serious bloodstream infections acquired in Indian hospitals emerge from unknown sources, pointing to hidden risks beyond the well-known threat of intravenous tubes.
The findings underline the need to find ways to identify and prevent hospital-acquired bloodstream infections from sources other than intravenous tubes, also called central lines (CL).
The researchers tracked 7,092 non-CL bloodstream infections over seven years and found an overall rate of 2.3 infections per 1,000 patient days — that is, for every 1,000 days patients collectively spent in hospital.
Neonatal intensive care units recorded the highest rate of infections — 4.8 per 1,000 patient days — followed by anaesthesia (3.9), neurology (3.6), burns (3.2) and medical ICUs (2.7).
In more than 60 per cent of the infected patients, the infection emerged within seven days of admission, highlighting early vulnerability.
“We need to know both the scale and sources of non-CL bloodstream infections to take effective preventive actions,” Purva Mathur, professor of microbiology at the All India Institute of Medical Sciences, New Delhi, who led the study, told The Telegraph.
Mathur and her colleagues from 33 government and 14 private hospitals across 25 cities — including Calcutta, Chandigarh, Chennai, Hyderabad, Jodhpur, Lucknow, Mumbai, and Vellore — have conducted the country’s largest analysis of non-CL bloodstream infections.
The Tata Medical Centre and the Institute of Postgraduate Medical Education and Research in Calcutta participated in the study.
CL-associated bloodstream infections occur when microbes enter the bloodstream through a tube inserted into a large vein, usually to deliver medicines or fluids over extended periods.
Because the tube reaches deep into the body, it provides a direct pathway for bacteria in the absence of strict infection control.
Non-CL infections, in contrast, emerge from what microbiologists call hidden or secondary sources — such as surgical wounds and urinary catheters.
Sometimes, the patient’s own gut, lung or skin bacteria can slip into the bloodstream during illness or medical procedures.
“Infection prevention strategies in hospitals have mainly targeted CL-associated infections, but equal emphasis should be given to non-CL risk factors,” Mathur and her colleagues have written in their study, published last week in the International Journal of Infectious Diseases.
Non-CL bloodstream infections account for roughly 40 per cent of all ICU bloodstream infections, Mathur said, emphasising the need for broader preventive measures.
The bacterial genus Klebsiella accounted for 34 per cent of the non-CL infections, followed by Acinetobacter (31 per cent) and Escherichia coli (11 per cent). Many isolates showed resistance to multiple antibiotics.
Over 80 per cent of Acinetobacter species were resistant to at least one carbapenem, a class of last-resort antibiotics used when standard treatments fail.
Patients who develop multi-drug-resistant, non-CL infections often remain hospitalised for days to weeks, driving up costs and the risk of life-threatening complications.
Experts say that identifying hidden infection sources and monitoring microbial resistance are essential to curbing deaths and improving outcomes.
Mathur noted that non-CL infections can sometimes emerge from secondary sites in the body, such as wounds, lungs or a site of surgery.
“The only way to confirm a secondary non-CL infection is to culture samples from other sites and match the organisms,” she said.
“Improving culture practices is critical to determining the sources.”