Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 May;98(5):1281-1295.
doi: 10.4269/ajtmh.16-0922. Epub 2018 Mar 8.

Leptospirosis Outbreak After the 2014 Major Flooding Event in Kelantan, Malaysia: A Spatial-Temporal Analysis

Mohd Firdaus Mohd Radi  1   2 , Jamal Hisham Hashim  2   1 , Mohd Hasni Jaafar  2 , Rozita Hod  2 , Norfazilah Ahmad  2 , Azmawati Mohammed Nawi  2 , Gul Muhammad Baloch  3 , Rohaida Ismail  4 , Nur Izzah Farakhin Ayub  2
Affiliations

Leptospirosis Outbreak After the 2014 Major Flooding Event in Kelantan, Malaysia: A Spatial-Temporal Analysis

Mohd Firdaus Mohd Radi et al. Am J Trop Med Hyg. 2018 May.

Abstract

Severe floods increase the risk of leptospirosis outbreaks in endemic areas. This study determines the spatial-temporal distribution of leptospirosis in relation to environmental factors after a major flooding event in Kelantan, Malaysia. We conducted an observational ecological study involving incident leptospirosis cases, from the 3 months before, during, and three months after flood, in reference to the severe 2014 Kelantan flooding event. Geographical information system was used to determine the spatial distribution while climatic factors that influenced the cases were also analyzed. A total of 1,229 leptospirosis cases were notified within the three study periods where incidence doubled in the postflood period. Twelve of 66 subdistricts recorded incidence rates of over 100 per 100,000 population in the postflood period, in comparison with only four subdistricts in the preflooding period. Average nearest neighborhood analysis indicated that the cases were more clustered in the postflood period as compared with the preflood period, with observed mean distance of 1,139 meters and 1,666 meters, respectively (both at P < 0.01). Global Moran's I was higher in the postflood period (0.19; P < 0.01) as compared with the preflood period (0.06; P < 0.01). Geographic weighted regression showed that living close to water bodies increased the risk of contracting the disease. Postflooding hotspots were concentrated in areas where garbage cleanup occurred and the incidence was significantly associated with temperature, humidity, rainfall, and river levels. Postflooding leptospirosis outbreak was associated with several factors. Understanding the spatial distribution and associated factors of leptospirosis can help improve future disease outbreak management after the floods.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
The Malaysian state of Kelantan. This figure appears in color at www.ajtmh.org.
Figure 2.
Figure 2.
Distribution of leptospirosis cases. (A) Distribution 3 months before flooding. (B) Distribution during and 3 months after flooding. This figure appears in color at www.ajtmh.org.
Figure 3.
Figure 3.
Trend of leptospirosis cases during the study period. This figure appears in color at www.ajtmh.org.
Figure 4.
Figure 4.
Spatial difference in the incidence of leptospirosis cases per 100,000 population. (A) Incidence map 3 months before the flood. (B) Incidence of leptospirosis 3 months postflooding. This figure appears in color at www.ajtmh.org.
Figure 5.
Figure 5.
Spatial regression analysis of leptospirosis incidence risk in those living close to water bodies. This figure appears in color at www.ajtmh.org.
Figure 6.
Figure 6.
Hotspots of leptospirosis incidence and location of garbage cleanup sites during postflood period. This figure appears in color at www.ajtmh.org.
Figure 7.
Figure 7.
Population density of sub-districts in Kelantan. This figure appears in color at www.ajtmh.org.
Figure 8.
Figure 8.
Linear association between distance to garbage cleanup sites and number of cases.
Figure 9.
Figure 9.
Distribution of leptospirosis cases according to land use. (A) Incidence map 3 months before the flood. (B) Incidence of leptospirosis 3 months postflooding. This figure appears in color at www.ajtmh.org.
Figure 10.
Figure 10.
Leptospirosis cases and environmental parameters according to epidemiological weeks. This figure appears in color at www.ajtmh.org.
See this image and copyright information in PMC

References

    1. Azlee A, 2015. Worst floods in Kelantan, confirms NSC. Available at: http://www.themalaymailonline.com/print/malaysia/worst-floods-in-kelanta.... Accessed March 4, 2015.
    1. WHO , 2014. Leptospirosis Excerpt from “WHO Recommended Standards and Strategies for Surveillance, Prevention and Control of Communicable Diseases,” 1–4. Geneva, Switzerland: World Health Organization.
    1. WHO , 2003. Human Leptospirosis: Guidance for Diagnosis, Surveillance and Control. Geneva, Switzerland: World Health Organization.
    1. Lau C, 2009. Urbanisation, Climate Change, and Leptospirosis: Environmental Drivers of Infectious Disease Emergence. Universitas 21 International Graduate Research Conference: Sustainable Cities for the Future, 83–87. Available at: http://scholar.google.com/scholar?hl=en&btnG=Search&q=intitle:Urbanisati.... Accessed May 24, 2016.
    1. Wahab ZA, 2015. Epidemiology and Current Situation of Leptospirosis in Malaysia. Persidangan Kesihatan Persekitaran Pihak Berkuasa Tempatan 2015, September 8–9, 2015, 1–67.

Publication types