Researchers at NSW Health Pathology and the University of Sydney are working together to design a new integrated legionellosis surveillance system, using genomic testing to improve detection of legionella outbreaks.

Legion­naires’ dis­ease is an infec­tion of the lungs that is spread to humans by breath­ing in droplets of water con­t­a­m­i­nat­ed with legionel­la bac­te­ria. The most com­mon sources of this bac­te­ria are air con­di­tion­ing cool­ing towers.

There have been sev­er­al large out­breaks of Legion­naires’ dis­ease in Syd­ney in the past few years, and pub­lic health author­i­ties need bet­ter tools to help them con­trol out­breaks more quickly.

A new research project is aim­ing to bring togeth­er the lat­est in genomics tech­nol­o­gy and a range of pub­lic health organ­i­sa­tions to improve how we detect and respond to outbreaks.

NSW Health Pathol­o­gy (NSWHP) is the host organ­i­sa­tion for the project being led by Chief Inves­ti­ga­tors, Pro­fes­sor Vitali Sintchenko (NSWHP and Uni­ver­si­ty of Syd­ney) and Dr Eby Sim (Uni­ver­si­ty of Syd­ney). (pic­tured above)

The research team is also part­ner­ing with Health Pro­tec­tion NSW, and Pub­lic Health Units, in West­ern Syd­ney and South East Syd­ney Local Health Districts.

They’ve been award­ed a $500,000 Trans­la­tion­al Research Grant through the NSW Office of Health and Med­ical Research to assess the effec­tive­ness of whole-genome sequenc­ing for inte­grat­ed sur­veil­lance for legionellosis.

“Pub­lic Health author­i­ties aim to iden­ti­fy clus­ters of cas­es as soon as pos­si­ble in order to remove the source of infec­tion and pre­vent fur­ther spread in the com­mu­ni­ty,” Vitali explains.

“Grow­ing Legionel­la in the lab is a com­plex process, it takes a long time, and cul­tures are not often avail­able because more cas­es of legionel­la infec­tion are diag­nosed by PCR testing.

“So, this project is going to use clever genomics that can col­lect genom­ic infor­ma­tion with­out cul­ture direct­ly from res­pi­ra­to­ry sam­ples. That will increase the num­ber of rel­e­vant cas­es that can be inves­ti­gat­ed with­out rely­ing on culture.

“The oth­er part of the project is to bring togeth­er mul­ti­ple stake­hold­ers – pub­lic health units, spe­cial­ists in envi­ron­men­tal health, clin­i­cal and envi­ron­men­tal microbiology.

“Our team is focused on a whole-of-sys­tem approach so that dif­fer­ent types of data can be mapped togeth­er, and genomics can hope­ful­ly save time by iden­ti­fy­ing com­mon­al­i­ties, or links between cas­es, that oth­er­wise would not have been recog­nised as part of a cluster.”

Dr Eby Sim says the genom­ic sequenc­ing tech­nol­o­gy being used by the research team at West­mead will sig­nif­i­cant­ly stream­line the process of search­ing for match­es between samples.

“Legionel­la is hard to grow in a lab­o­ra­to­ry, and the cul­ture takes many days,” he said.

“Here, we are attempt­ing to bypass the growth of Legionel­la pneu­mophi­la in the lab­o­ra­to­ry and direct­ly ‘fish out’ its genom­ic sig­na­ture from a spec­i­men, which is very help­ful for link­ing cas­es and clus­ters together.”

“We also want to make sure that out­breaks don’t keep expand­ing so we can assist pub­lic health units in find­ing hot spots and respond­ing to them faster,” said Eby.

Vitali says the research project will take two years to complete.

“The suc­cess of this com­pet­i­tive grant appli­ca­tion is due to our part­ner­ship between Health Pro­tec­tion NSW, the Uni­ver­si­ty of Syd­ney and also sup­port from ICPMR and NSW Health Pathology’s Pub­lic Health Pathol­o­gy office.

“What we want to see, if every­thing goes as we planned, is that NSW Health Pathology’s genomics is inte­grat­ed into the envi­ron­men­tal and pub­lic health mon­i­tor­ing and response, reduc­ing the time it takes to iden­ti­fy clus­ters of legionellosis.”

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