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Spatial epidemiology of suspected clinical leptospirosis in Sri Lanka

  • C. ROBERTSON (a1), T. A. NELSON (a2) and C. STEPHEN (a3)

Summary

Leptospirosis is one of the most widespread zoonoses in the world. A large outbreak of suspected human leptospirosis began in Sri Lanka during 2008. This study investigated spatial variables associated with suspected leptospirosis risk during endemic and outbreak periods. Data were obtained for monthly numbers of reported cases of suspected clinical leptospirosis for 2005–2009 for all of Sri Lanka. Space–time scan statistics were combined with regression modelling to test associations during endemic and outbreak periods. The cross-correlation function was used to test association between rainfall and leptospirosis at four locations. During the endemic period (2005–2007), leptospirosis risk was positively associated with shorter average distance to rivers and with higher percentage of agriculture made up of farms <0·20 hectares. Temporal correlation analysis of suspected leptospirosis cases and rainfall revealed a 2-month lag in rainfall-case association during the baseline period. Outbreak locations in 2008 were characterized by shorter distance to rivers and higher population density. The analysis suggests the possibility of household transmission in densely populated semi-urban villages as a defining characteristic of the outbreak. The role of rainfall in the outbreak remains to be investigated, although analysis here suggests a more complex relationship than simple correlation.

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Copyright

Corresponding author

*Author for correspondence: Dr C. Robertson, Department of Geography and Environmental Studies, Wilfrid Laurier University, 75 University Ave West, Waterloo, ON, N2L 3C5, Canada. (Email: crobertson@wlu.ca)

References

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1.Bharti, AR, et al. Leptospirosis: a zoonotic disease of global importance. Lancet Infectious Diseases 2003; 3: 757771.
2.Pappas, G, et al. The globalization of leptospirosis: worldwide incidence trends. International Journal of Infectious Diseases 2008; 12: 351357.
3.Sri Lanka Epidemiology Unit. An interim analysis of leptospirosis outbreak in Sri Lanka – 2008, Colombo, Sri Lanka: Ministry of Healthcare Nutrition, 2008.
4.Sri Lanka Department of Provincial Health Services. Annual Health Bulletin, Central Province 2007, Sri Lanka, 2008.
5.Levett, PN. Leptospirosis. Clinical Microbiology Reviews 2001; 14: 296326.
6.Agampodi, SB, et al. A preliminary study on prevalent serovars of leptospirosis among patients admitted to teaching hospital, Kandy, Sri Lanka. Indian Journal of Medical Microbiology 2008; 26: 405406.
7.Koizumi, N, et al. Serological and genetic analysis of leptospirosis in patients with acute febrile illness in Kandy, Sri Lanka. Japan Journal of Infectious Diseases 2009; 62: 474475.
8.Galloway, RL, Levett, PN. Application and validation of PFGE for serovar identification of Leptospira clinical isolates. PLoS Neglected Tropical Diseases 2010; 4: e824.
9.Sullivan, ND. Leptospirosis in animals and man. Australian Veterinary Journal 1974; 50: 216223.
10.Odiit, M, et al. Using remote sensing and geographic information systems to identify villages at high risk for rhodesiense sleeping sickness in Uganda. Transactions of the Royal Society of Tropical Medicine and Hygiene 2006; 100: 354362.
11.Moffett, A, Shackelford, N, Sarkar, S. Malaria in Africa: vector species' niche models and relative risk maps. PLoS ONE 2007; 2(9).
12.Reis, RB, et al. Impact of environment and social gradient on Leptospira infection in urban slums. PLoS Neglected Tropical Diseases 2008; 2: e228.
13.Moore, M, Gould, P, Keary, BS. Global urbanization and impact on human health. International Journal of Hygiene and Environmental Health 2003; 206: 269278.
14.Maciel, EAP, et al. Household transmission of Leptospira infection in urban slum communities. PLoS Neglected Tropical Diseases 2008; 2(1).
15.Thaipadungpanit, J, et al. A dominant clone of Leptospira interrogans associated with an outbreak of human leptospirosis in Thailand. PLoS Neglected Tropical Diseases 2007; 1: e56.
16.Phulsuksombati, D, et al. Leptospires in rodent, northeastern region 1999–2000. Journal of Health Science 2001; 10: 516525.
17.Victoriano, A, et al. Leptospirosis in the Asia Pacific region. BMC Infectious Diseases 2009; 9: 147.
18.Domroes, M, Ranatunge, E. Analysis of inter-station daily rainfall correlation during the Southwest Monsoon in the Wet Zone of Sri Lanka. Geografiska Annaler. Series A: Physical Geography 1993; 75: 137148.
19.Zubair, L. El Niño-southern oscillation influences on rice production in Sri Lanka. International Journal of Climatology 2002; 22: 249260.
20.Madsen, T, Shine, R. Rainfall and rats: climatically-driven dynamics of a tropical rodent population. Austral Ecology 1999; 24: 8089.
21.Davis, S, Calvet, E. Fluctuating rodent populations and risk to humans from rodent-borne zoonoses. Vector-Borne & Zoonotic Diseases 2005; 5: 305314.
22.Mills, JN. The role of rodents in emerging human disease: examples from the hantaviruses and arenaviruses. In: Singleton, GR, Hinds, LA, Leirs, H, Zhang, Z, eds. Ecologically Based Management of Rodent Pests. Australian Centre for International Agricultural Research. Canberra, Australia, 1999, pp. 134160.
23.Sanders, EJ, et al. Increase of leptospirosis in dengue-negative patients after a hurricane in Puerto Rico in 1996. American Journal of Tropical Medicine and Hygiene 1999; 61: 399404.
24.Tassinari, WS, et al. Detection and modelling of case clusters for urban leptospirosis. Tropical Medicine & International Health 2008; 13: 503512.
25.Dassanayake, D, et al. Evaluation of surveillance case definition in the diagnosis of leptospirosis, using the microscopic agglutination test: a validation study. BMC Infectious Diseases 2009; 9: 48.
26.Diggle, P. Time Series: A Biostatistical Introduction. Oxford: Oxford University Press, 1990; 257 pp.
27.Naus, JI. The distribution of the size of the maximum cluster of points on a line. Journal of the American Statistical Association 1965; 60: 532538.
28.Kulldorff, M, Nagarwalla, N. Spatial disease clusters: detection and inference. Statistics in Medicine 1995; 14: 799810.
29.Kulldorff, M. Prospective time periodic geographical disease surveillance using a scan statistic. Journal of the Royal Statistical Society Series A 2001; 164: 6172.
30.Kulldorff, M.Information Management Services. SaTScan, 2010.
31.Mukthar, ZAM, Dangolla, A, Priyantha, MAR. Serological detection of Leptospira serovars in house rats (Mus musculus) and roof rats (Rattus rattus) in Kandy. In: Proceedings of the 62nd Annual Scientific Sessions of the Sri Lanka Veterinary Association. Colombo, Sri Lanka, 7 May 2010.
32.Taylor, KD, Green, MG. The influence of rainfall on diet and reproduction in four African rodent species. Journal of Zoology 1976; 180: 367389.
33.Agampodi, S, Peacock, SJ, Thevanesam, V. The potential emergence of leptospirosis in Sri Lanka. Lancet Infectious Diseases 2009; 9: 524526.
34.Clement, J, et al. First evidence of fatal hantavirus nephropathy in India, mimicking leptospirosis. Nephrology Dialysis Transplantation 2006; 21: 826827.
35.Hindrichsen, S, et al. Hantavirus infection in Brazilian patients from Recife with suspected leptospirosis. Lancet 1993; 341: 50.
36.Clement, J, et al. Urban leptospirosis versus hantavirus infection in Brazil. Lancet 1999; 354: 20032004.
37.Sugunan, AP, et al. Risk factors associated with leptospirosis during an outbreak in Middle Andaman, India. Indian Journal of Medical Research 2009; 130: 6773.
38.Bovet, P, et al. Factors associated with clinical leptospirosis: a population-based case-control study in the Seychelles (Indian Ocean). International Journal of Epidemiology 1999; 28: 583590.
39.Agampodi, SB, et al. Do people know adequately about leptospirosis? A knowledge assessment survey in post outbreak situation – Sri Lanka. International Journal of Preventive Medicine 2010; 1(3).

Keywords

Spatial epidemiology of suspected clinical leptospirosis in Sri Lanka

  • C. ROBERTSON (a1), T. A. NELSON (a2) and C. STEPHEN (a3)

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