Socio-epidemiological and land cover risk factors for melioidosis in Kedah, Northern Malaysia

Abstract

Background Melioidosis, a fatal infectious disease caused by Burkholderia pseudomallei , is increasingly diagnosed in tropical regions. However, data on risk factors and the geographic epidemiology of the disease are still limited. Previous studies have also largely been based on the analysis of case series data. Here, we undertook a more definitive hospital-based matched case-control study coupled with spatial analysis to identify demographic, socioeconomic and landscape risk factors for bacteremic melioidosis in the Kedah region of northern Malaysia. Methodology/Principal findings We obtained patient demographic and residential information and clinical presentation and medical history data from 254 confirmed melioidosis cases and 384 matched controls attending Hospital Sultanah Bahiyah (HSB), the main tertiary hospital of Alor Setar, the capital city of Kedah, during the period between 2005 and 2011. Crude and adjusted odds ratios employing conditional logistic regression analysis were used to assess if melioidosis in this region is related to risk factors connected with socio-demographics, various behavioural characteristics, and co-occurring diseases. Spatial clusters of cases were determined using a continuous Poisson model as deployed in SaTScan. A land cover map in conjunction with mapped case data was used to determine disease-land type associations using the Fisher’s exact test deploying simulated p -values. Crude and adjusted odds ratios indicate that melioidosis in this region is related to gender (males), race, occupation (farming) and co-occurring chronic diseases, particularly diabetes. Spatial analyses of disease incidence, however, showed that disease risk and geographic clustering of cases are related strongly to land cover types, with risk of disease increasing non-linearly with the degree of human modification of the natural ecosystem. Conclusions/Significance These findings indicate that melioidosis represents a complex socio-ecological public health problem in Kedah, and that its control requires an understanding and modification of the coupled human and natural variables that govern disease transmission in endemic communities.

Multi locus sequence typing of clinical Burkholderia pseudomallei isolates from Malaysia

“…pseudomallei from this study were more frequently isolated from males of Malay ethnicity with agriculture or farming as the dominant occupation. Hassan et al [ 26 ] also reported similar demographics for B . pseudomallei clinical cases in the state of Kedah, Malaysia.…”

“…The B. pseudomallei from this study were more frequently isolated from males of Malay ethnicity with agriculture or farming as the dominant occupation. Hassan et al [26] also reported similar demographics for B. pseudomallei clinical cases in the state of Kedah, Malaysia. In Malaysia, there is a higher tendency for males to be involved in soil and agriculturebased occupations and activities that may have facilitated exposure to the bacterium.…”

Risk Factors for Mortality in Melioidosis: A Single-Centre, 10-Year Retrospective Cohort Study

“…Fifty-five patients (75.3%) were males with an average age of 49.5 ± 15.36 years at presentation, which was comparable with studies done by Saravu et al, 2010, and Currie et al, 2004 ( Table 1 ). The reason for male preponderance may be explained by more frequent exposure to soil and water while in professions like farming or greater incidence of alcoholism among males [ 9 , 15 ]. The most common comorbid condition was DM with 53 (72.6%) patients, followed by hypertension in 24 (32.8%) patients.…”

“…Melioidosis is a disease of alarming fatality, with overall mortality rates varying between 19 and 54% in different endemic regions [ 9 ]. The recommended antimicrobial therapy includes ceftazidime, trimethoprim/sulfamethoxazole, and doxycycline [ 1 ], but established melioidosis is hard to treat, leading to unprecedented patient demises [ 10 ].…”

In-vitro activity of β-lactams/trimethoprim-sulfamethoxazole combinations against different strains of Burkholderia pseudomallei

“…In Malaysia, cases of melioidosis are relatively high in hyper-endemic areas especially in states where agriculture is the main economic activity. Recently, melioidosis cases in Kedah and Pahang states have been reported at 16.35 per 100 000 populations and 4.3 per 100 000 populations per year, respectively (Abu Hassan et al, 2019).…”