Search

Aims: This study describes 47 presentations of suspected leptospirosis in general practice in New Zealand. Our primary aim was to assess the laboratory diagnosis of leptospirosis in these patients, by comparing polymerase chain reaction (PCR) tests, microscopic agglutination test (MAT) and culture results., Methods: Patients suspected of leptospirosis were recruited from general practices in the Waikato (n=17) and Wairoa (n=30) between August 2011 and June 2015. Blood and urine samples were tested for leptospirosis at two diagnostic laboratories and one research laboratory using PCR tests, MAT and culture., Results: Forty-seven patients were recruited for this study: 37 during the acute phase of the illness (within 10 days of symptom onset) and 10 after the acute phase. Eleven of the acute phase patients (11/37, 30%) and two of the later phase patients (2/10, 20%) returned positive leptospirosis test results. The 11 acute phase leptospirosis positive patients had the following positive diagnostic tests: PCR and paired MAT (+/- blood culture) (n=3), PCR only (+/- blood culture) (n=4), paired MAT only (n=3) and blood culture only (n=1). Urine PCR (performed only on Wairoa patients) was the only positive test for two of these patients., Conclusion: About a quarter of farm workers and meat workers presenting to general practice with flu-like symptoms will have leptospirosis, but they will not be diagnosed unless appropriately tested, and then they may only test positive for some of the tests available. To increase the likelihood of making a diagnosis, clinicians should order multiple laboratory tests, including blood and urine PCR and a paired MAT., Competing Interests: Nil.

Aim: We report a quantification and visualisation of the association between the time to notify public health service (PHS) and the duration and size of institutional gastroenteritis outbreaks, and explore the seasonality and trend of the outbreaks., Method: Descriptive analysis was performed on institutional gastroenteritis outbreak data from a North Island PHS (1 January 2009-31 December 2014). Time-series analysis was used to explore the seasonality and trend of outbreaks. Multivariate analyses were performed to quantify the association between the time to notify PHS and the duration and size of outbreaks., Results: One hundred and seventy-five gastroenteritis outbreaks (from 58 facilities) were included in descriptive analyses. A significant increasing trend (p=0.01) without seasonal pattern was confirmed by time-series analysis. Shorter notification time was associated with shorter duration and smaller size of outbreaks, eg, duration of outbreaks when time to notify was ≥7 days, was 3.4 days (p=0.001, 95% CI=3.1-3.7) longer than baseline time to notify (0-1 day)., Conclusion: Prompt notification to the PHS appears to be a factor associated with reduced outbreak duration and size., Competing Interests: Nil.

Aim: We report a one-health investigation of three cases of leptospirosis on a dairy farm with unvaccinated cattle in New Zealand. The cases are discussed in the context of diagnostics, risk factors, persistence of symptoms and outbreak mitigation measures., Method: Clinical and laboratory records from the human cases were reviewed and serological and molecular investigations were conducted into the Leptospira status of cattle and pigs on the farm., Results: Cases presented early in their illness and all three were confirmed within seven days of onset of symptoms by urine PCR and within 18 days by convalescent MAT (two Hardjo, one Pomona). Cattle and pigs had serological evidence of recent infection with Hardjo/Pomona and Pomona/Copenhageni respectively. Pigs were slaughtered and cattle were vaccinated. Post-exposure prophylaxis was given to staff in-contact with the milking herd until the herd had antibiotic treatment at drying-off (approximately four months after the initial case)., Conclusion: The utility of PCR testing for Leptospira DNA as both an early and rapid test for leptospirosis was demonstrated. Two of three cases reported persistence of symptoms at least six months after the acute episode and one of these remains unable to work. Risk mitigation measures such as post-exposure prophylaxis, animal vaccination, heightened clinical suspicion of leptospirosis and recognition of context specific risk factors (eg, effluent spreading) demonstrate the value of medical and veterinary experts working together., Competing Interests: Nil.

Aims: To undertake a pilot study to measure the sero-prevalence to Leptospira serovars Hardjo and Pomona in an occupationally exposed group. To evaluate worker age, sex and previous clinical episodes of leptospirosis as risk factors for sero-positivity., Methods: A cross-sectional sero-prevalence study was conducted in February and March 2008 at a predominantly sheep slaughterhouse in Hawke's Bay, New Zealand. A single blood sample was collected from 242 meatworkers, comprising 145 men and 97 women. Sera were tested by the Microscopic Agglutination Test (MAT) with a titre cut point of 1:24, using serovars Pomona and Hardjo as antigens. Age, sex, and details of previous clinical episodes of leptospirosis were recorded., Results: Overall sero-prevalence was 9.5%. Ten (4.1%) workers were positive to serovar Hardjo (titres 1:24-1:192), 13 (5.4%) were positive to serovar Pomona (titres 1:24-1:768), and one worker was positive for both serovars. Sero-prevalence was 13.1% and 4.1% in men and women, respectively. The median age for sero-positive workers was 54 years while that for sero-negative workers was 48 years. Twenty-three workers (9.5%) reported a leptospirosis disease episode 1-35 years previously, and 14 of those were sero-positive in the current study., Conclusion: The sero-prevalence observed suggests significant exposure to leptospirosis from sheep in meatworkers in the slaughterhouse studied. This sero-prevalence was similar to that reported in a survey in 1982. Further study is needed to determine the link between sero-prevalence and incidence, whether the prevalence of leptospirosis is similar in other slaughterhouses, and to develop a better understanding of risk factors important for the reduction of exposure of this occupationally acquired disease.