If the study carried out by a team of researchers from DY Patil Medical College (DYPMC) is to be believed, respiratory devices like nebulisers and oxygen humidifiers given to critical patients in hospitals could be a host to fungi and bacteria.

A thorough hospital infection control programme and simple measures like regular hand-washing of staffers can bring down occurrence of such pathogens by nearly 75%, found the study.

Published in the June 2013 issue of Journal of Clinical and Diagnostic Research (JCDR), the study has been carried out by four doctors from pulmonary and microbiology departments of the college after drawing 70 swab samples from the oxygen humidifiers and nebulisers (used to help in respiration by patients) from intensive care units (ICUs), wards and outpatient departments (OPDs).

“Approximately 10-40% of all hospital acquired infections are pulmonary, which lead to grave complications. We studied respiratory care equipment like ventilators, humidifiers, nebulisers to see if they are colonised by fungi or bacteria. They could then act as potential vehicles of major infections,” said DYPMC assistant professor of microbiology Dr Savita Jadhav.

Of the 75% samples processed in which fungi was isolated, the most common fungi was Aspergillus fumigatus (33.96% samples) followed by Aspergillus niger (18.86%). These fungi, commonly found in soil and decaying heaps, are known to cause disease in individuals with compromised immunity.

Even more shocking is the fact that of the total 61 (87.14%) bacterial isolates, 42 (68.85%) were gram-negative bacteria, out of which 17 samples were multi-drug resistant bacteria which are known to be resistant to many anti-biotics.

“The patients of obstructive airway disease such as asthma, often require nebulisation and oxygen therapy besides other ICU patients. If the oxygen humidifier chambers or the nebuliser chambers are colonised by fungi, the clinicians may actually be directly delivering the fungal allergens to the patients’ airways which maybe the cause of delayed response to asthma therapy. Also, in bacterial isolates, many bacteria were resistant to even third generation antibiotics indicating serious multi-drug resistant infections,” DYPMC pulmonary department head Dr Tushar Sahastrabuddhe said.

Later, the researchers carried out a disinfection protocol by first washing these devices with sterile water and soap followed by 70% ethanol swipe cleaning. Hospital workers were made to use alcohol-based hand rubs before and after patient contact. On collecting the swabs again from the same wards and ICUs after disinfection, the colonisation rate for fungi reduced to only 15%, while bacterial colonisation rate came down to 12% from 87%.