Risk factors and burden of acute Q fever in older adults in New South Wales: a prospective cohort study

Abstract

Objectives: To measure the acute burden of and to identify risk factors associated with notified Q fever in older adults in New South Wales. Design, settings and participants: A prospective cohort of adults aged 45 years and over (the 45 and Up Study) recruited during 2006–2009 and followed using linked Q fever notifications, hospital records and death records during 2006–2012. Main outcome measures: Incident cases of Q fever, based on a linked Q fever notification; proportion of cases with a Q fever‐coded hospitalisation. Results: A total of 266 906 participants were followed up for 1 254 650 person‐years (mean, 4.7 ± 1.0 years per person). In our study population, the incidence of notified Q fever during follow‐up was 3.6 (95% CI, 2.7–4.8) per 100 000 person‐years. After adjustments, age (≥ 65 years v 45–54 years: hazard ratio [HR], 0.39; 95% CI, 0.16–0.96), sex (women v men: HR, 0.48; 95% CI, 0.26–0.88), and area and type of residence (P < 0.001 for trend) remained significantly associated with Q fever. Compared with those living in an inner regional area but not on a farm, the risk of notified Q fever was highest for those living on a farm in outer regional or remote areas (HR, 11.98; 95% CI, 5.47–26.21), followed by those living on a farm in inner regional areas (HR, 4.95; 95% CI, 1.79–13.65). Of notified Q fever cases, 15 of 39 (38%) had been hospitalised with a diagnosis consistent with Q fever. Conclusions: Adults living on a farm in outer regional and remote areas are at a substantially greater risk of contracting Q fever. This suggests that, as well as targeting specific occupational groups for vaccination, there would be benefits in increasing public awareness of Q fever and vaccination among those living on and near farms in outer regional and remote areas of Australia.

Endemic Q Fever in New South Wales, Australia: A Case Series (2005–2013)

“…Increased uptake of the Q fever vaccine by young adults (≥ 18 years), in rural Australia, should be encouraged. 28 …”

“…There have been previous epidemiological studies of Q fever in Queensland, 5,6,12,13,[19][20][21][22] Victoria, 7,8 and comparisons, 23,24 but there are limited data available on Q fever in NSW. [25][26][27][28] A seroprevalence study in the Hunter New England (northeast) region of NSW showed a seroprevalence range from 0.5% in the city (Newcastle) to a maximum of 22% in a rural area. 29 A 10-year summary (2001-2010) of the NSW official Q fever notification data 30 overlapped with the current study (2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013).…”

Seroprevalence of Q fever among metropolitan and non‐metropolitan blood donors in New South Wales and Queensland, 2014–2015

“…Chronic Q fever, which may develop years after infection, is usually characterised by endocarditis, but may also include osteomyelitis and hepatitis . During 2013–2017, more than 2500 cases of Q fever were notified in Australia; studies have found that in 40–50% of notified cases patients were hospitalised for a median 4–6 days . A recent death linked to Q fever underscores the importance of preventing this infection …”

Linking administrative data sets of inpatient infectious diseases diagnoses in far North Queensland: a cohort profile

“…Australian infectious diseases cohort studies have involved: organ specific infections such as respiratory viral infections, 13 infections such as Q fever 12 and S. aureus bacteraemia 14 as well as specific patients such as asplenics 16 and haematology-oncology. 17 The value of Australian patient cohorts for infectious diseases research is further shown by the multiple studies deriving from the 45 and up study of ageing, 18 Triple I Western Australian birth cohort 15 and Victorian Post-Splenectomy Registry.…”