A 2018/2019 Summer Studentship research project
Every year during spring and summer, gardeners are hospitalised with pneumonia caused by L. longbeachae infection. As there is no human-to-human transmission, infection is acquired solely from environmental sources following exposure to contaminated materials. It should therefore be preventable so long as appropriate protective measures are taken. We think that gardening gloves could become inoculated with L. longbeachae during normal gardening activities, and for some types of gloves it can remain there for some time, causing a potential risk. If we find this is the case, we can provide better advice to gardeners about the most appropriate gloves to use to minimise this risk.
Student: Krista Dawson
Supervisors: Dr Sandy Slow, Professor Stephen Chambers, Professor David Murdoch
Legionella longbeachae, primarily found in soil and composted plant material, is the predominant cause of Legionnaires’ disease, an often severe form of pneumonia that is common in New Zealand. Most cases occur in spring and summer, where those at greatest risk are gardeners, especially after using compost / potting mix. Current advice to help prevent infection is for gardeners to wear protective equipment such as gloves and masks. Yet in a case-control study, we found that wearing a mask and/or gloves was not protective. Similarly, under laboratory conditions, we have recently found that L. longbeachae can be cultured from some glove types for at least 7 days after inoculation, but on others we cannot culture it after more than 8 hours. It seems that gloves made of certain materials may allow L. longbeachae to survive, providing a potential infective source. However, we don’t know if it is common for a gardener’s gloves to have L. longbeachae on them following usual gardening activities, or whether the materials the gloves are made from influences this in the “real-world”.
To determine if L. longbeachae is on gloves after usual gardening activities and assess if its presence is related to any particular type of glove.
We will seek gardeners that routinely use gloves (up to 100 people) from gardening clubs and within the community in Christchurch to take part. We will request that the participants send us their gardening gloves as soon as practicable after use in a sealed bag (supplied), in exchange for a new pair of gloves. We will test the supplied gloves for the presence of L. longbeachae using qPCR and all that are positive will also be cultured. In case any L. longbeachae on the gloves is dislodged during transport to us, swabs will also be taken from the inside of the bag for qPCR testing. We will also administer a questionnaire to participants to ascertain their gardening habits, use of other protective equipment (e.g. masks), what they normally do with their gloves after gardening (cleaning and storage) and whether they use composts / potting mixes.
Student researcher’s component of the study
The student will assist with recruitment of the gardeners, administering the questionnaire and data analyses. They will be primarily responsible for the qPCR testing for L. longbeachae on the gloves / bag swabs and the culturing of PCR positive specimens.