Volume 196 - Issue 8
Spirochaetes and sunshine: leptospirosis in the aftermath of the Queensland floods
Authors: Hugh Wright, Katie Goot and Benjamin Rogers
Med J Aust 2012; 196 (8): 500-502. || doi: 10.5694/mja12.10046
Published online: 7 May 2012
Published online: 7 May 2012
To the Editor: Extensive rainfall in Queensland from December 2010 to January 2011 led to much of the state being declared a disaster zone. We report on a cluster of patients requiring hospitalisation with an acute febrile illness after exposure to floodwater in Central Queensland.
During the height of the flood emergency, four adults (23-56 years of age) from ...
To the Editor: Extensive rainfall in Queensland from December 2010 to January 2011 led to much of the state being declared a disaster zone. We report on a cluster of patients requiring hospitalisation with an acute febrile illness after exposure to floodwater in Central Queensland.
During the height of the flood emergency, four adults (23–56 years of age) from a narrow geographical area around a rural township presented with a similar clinical syndrome over a 2-day period. All cases presented with a febrile illness characterised by myalgia, headache and malaise. Significant exposure to floodwaters involving hours of immersion above the knees over several days was uniformly reported. All patients required hospitalisation and were commenced on intravenous antibiotics. An electrocardiogram of one patient with chest pain showed inferolateral ST-segment elevation with subsequent cardiac magnetic resonance imaging showing multifocal myocarditis.
Initial polymerase chain reaction results for leptospirosis on serum were positive in all cases. This diagnosis was later confirmed, with microagglutination testing demonstrating a significant rise in paired serology with elevated titres to Leptospira borgpetersenii serovar Arborea. Of note, the last case reported from this district occurred in 2002.1 This outbreak corresponds with an overall increase in leptospirosis diagnosed in Queensland in early 2011 (unpublished data). Common clinical features among our patients, and those seen in leptospirosis, are shown in the Box.
Leptospirosis is a common bacterial zoonosis. Humans become infected via direct contact with animal vectors (eg, rodents, livestock, domestic pets) or through contamination of the environment by urine from infected animals.2 Transmission to humans may occur via contaminated floodwater, either by ingestion or through mucous membranes and skin.3
Leptospirosis outbreaks due to flooding may become more common as global climate change increases the frequency and severity of extreme weather events.4 Globally, outbreaks of leptospirosis associated with flooding have been well described, and in some regions, flooding is the major risk factor for transmission.5 The increase in risk is likely multifactorial; closer contact between animal hosts and humans, contamination of floodwaters directly and damage to water and sanitation networks may all contribute.5 Clinicians should remain vigilant for leptospirosis as a cause for a febrile illness in this setting.
Competing interests
No relevant disclosures.
References
- Symonds M. National leptospirosis surveillance report number 13. WHO/FAO/OIE Collaborating Centre for Reference and Research on Leptospirosis. http://www.health.qld.gov.au/qhcss/qhss/lepto/documents/04_annual.pdf (accessed Apr 2012).
- McBride AJ, Athanazio DA, Reis MG, Ko AI. Leptospirosis. Curr Opin Infect Dis 2005; 18: 376-386. 0_i1142933
- Bharti AR, Nally JE, Ricaldi JN, et al. Leptospirosis: a zoonotic disease of global importance. Lancet Infect Dis 2003; 3: 757-771. 0_i1142935
- Lau CL, Smythe LD, Craig SB, Weinstein P. Climate change, flooding, urbanisation and leptospirosis: fuelling the fire? Trans R Soc Trop Med Hyg 2010; 104: 631-638. 0_i1142937
- Vanasco NB, Schmeling MF, Lottersberger J, et al. Clinical characteristics and risk factors of human leptospirosis in Argentina (1999–2005). Acta Trop 2008; 107: 255-258. 0_i1142939