Leptospirosis: An important zoonosis acquired through work, play and travel

• Published in: Australian family physician Vol. 47; no. 3; pp. 105 - 110
• Main Authors: Lau, Colleen L, Townell, Nicola, Stephenson, Eloise, van den Berg, Debra, Craig, Scott B
• Format: Journal Article
• Language: English
• Published: Sydney Copyright Agency Limited (Distributor) 01.03.2018
• Subjects: Antibiotics; Bacteria; Climate change; Developing countries; Disease; Disease prevention; Epidemiology; Floods; Illnesses; Infections; Laboratories; LDCs; Leptospirosis; Meningitis; Population; Risk factors; Systematic review; Tropical diseases; Typhoid; Urine; Zoonoses; New Zealand; Queensland Australia; Philippines; Canberra Australian Capital Territory Australia; Brazil; Australia; Oceania
• ISSN: 2208-7958

Globally, leptospirosis is an emerging infectious disease with a rising incidence, increasing frequency and severity of outbreaks, and evolving climatic, sociodemographic and environmental drivers of transmission.2 Recently, unprecedented outbreaks have occurred as a result of the combined forces of climate change, flooding, population growth, urbanisation (typically associated with poverty and slums in developing countries), and agricultural intensification to meet the increasing demands for food.3 Epidemiology and risk factors Leptospirosis is responsible for about one million severe cases and 60,000 deaths per year worldwide.4 The incidence of leptospirosis is highest in tropical and subtropical areas, and disease burden is particularly high in Oceania.5 Summary statistics of cases reported to the National Notifiable Disease Surveillance System (NNDSS) in Australia are shown in Figure 2.Queensland had the greatest infection burden, particularly in the Cairns and Hinterland region,7 and the spike in cases in 2011 was attributed to an outbreak after unprecedented flooding across Queensland.8'9 Most cases occurred in the summer months, and in young and middle-aged males.6 In Australia, occupational exposure is the predominant source of infection, particularly in livestock and dairy farmers, abattoir and meat workers, and banana workers (through exposure to rodents).10 Infection through recreational exposure is also common, mostly from white water rafting, kayaking, ecotourism and other outdoor activities.11 International travel, particularly to tropical, developing countries, is an important source of occupational and recreational exposure.11 In tropical, developing countries, including Australia's neighbours in the Asia Pacific region, environmental and climatic drivers are important.Human vaccines are rarely used (none are available in Australia) because of limited effectiveness, adverse reactions and short duration of protection.26 Key points * For patients with risk factors, leptospirosis should be considered as a differential diagnosis of undifferentiated febrile illness and the complications discussed above. * A high index of clinical suspicion is required to ensure early diagnosis and treatment, and to minimise the risk of complications. * Patients involved in high-risk activities should be advised to seek medical care promptly if they develop a fever. * Diagnosis is confirmed by serology or culture, but PCR is valuable in the early phase of the infection. * Severe cases and complications should be referred to a hospital for inpatient management.Resources * eTG, Antibiotic, https://tgldcdp.tg.org. au/etgAccess * WHO/FAO/OIE Leptospirosis Reference Laboratory, Health Support Queensland, www.health.qld.gov.au/ qhcss/lepto * Queensland Health's guidelines for public health units, including laboratory diagnosis, case definitions, preventative measures, www.health.qld.gov.au/ cdcg/index/lepto * Prevention and control of leptospirosis (educational materials for farmers), http://saferfarms.org.nz/guides/ prevention-and-control-of-leptospirosis * World Health Organization, Leptospirosis, www.who.int/topics/ leptospirosis/en * US Centres for Disease Control and Prevention, Leptospirosis, www.cdc. gov/leptospirosis.