Climatic drivers of melioidosis in Laos and Cambodia: a 16-year case series analysis

Philip L Bulterys, PhD; Michelle A Bulterys, BA; Koukeo Phommasone, MSc; Manophab Luangraj, MD; Mayfong Mayxay, MD; Sabine Kloprogge, MSc; Thyl Miliya, MD; Manivanh Vongsouvath, MSc; Paul N Newton, ProfMRCP; Rattanaphone Phetsouvanh, MD; Christopher T French, PhD; Jeff F Miller, ProfPhD; Paul Turner, FRCPath; David A B Dance, ProfFRCPath

The Lancet Planetary Health (Aug 2018)

Climatic drivers of melioidosis in Laos and Cambodia: a 16-year case series analysis

Philip L Bulterys, PhD,
Michelle A Bulterys, BA,
Koukeo Phommasone, MSc,
Manophab Luangraj, MD,
Mayfong Mayxay, MD,
Sabine Kloprogge, MSc,
Thyl Miliya, MD,
Manivanh Vongsouvath, MSc,
Paul N Newton, ProfMRCP,
Rattanaphone Phetsouvanh, MD,
Christopher T French, PhD,
Jeff F Miller, ProfPhD,
Paul Turner, FRCPath,
David A B Dance, ProfFRCPath

Affiliations

Philip L Bulterys, PhD: UCLA-Caltech Medical Scientist Training Program, David Geffen School of Medicine, Los Angeles, CA, USA; Molecular Biology Institute, Los Angeles, CA, USA; Department of Microbiology, Immunology, and Molecular Genetics, Los Angeles, CA, USA; Correspondence to: Dr Philip L Bulterys, UCLA-Caltech Medical Scientist Training Program, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
Michelle A Bulterys, BA: School of Public Health, University of Washington, Seattle, WA, USA
Koukeo Phommasone, MSc: Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos
Manophab Luangraj, MD: Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos
Mayfong Mayxay, MD: Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Faculty of Postgraduate Studies, University of Health Sciences, Ministry of Health, Vientiane, Laos
Sabine Kloprogge, MSc: Cambodia Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, Cambodia
Thyl Miliya, MD: Cambodia Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, Cambodia
Manivanh Vongsouvath, MSc: Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos
Paul N Newton, ProfMRCP: Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
Rattanaphone Phetsouvanh, MD: Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
Christopher T French, PhD: Department of Microbiology, Immunology, and Molecular Genetics, Los Angeles, CA, USA; California NanoSystems Institute UCLA, Los Angeles, CA, USA
Jeff F Miller, ProfPhD: Molecular Biology Institute, Los Angeles, CA, USA; Department of Microbiology, Immunology, and Molecular Genetics, Los Angeles, CA, USA; California NanoSystems Institute UCLA, Los Angeles, CA, USA
Paul Turner, FRCPath: Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Cambodia Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, Cambodia
David A B Dance, ProfFRCPath: Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK

Journal volume & issue: Vol. 2, no. 8
pp. e334 – e343

Abstract

Read online

Summary: Background: Burkholderia pseudomallei is the cause of melioidosis, a serious and difficult to treat infection that is endemic throughout the tropics. Melioidosis incidence is highly seasonal. We aimed to identify the climatic drivers of infection and to shed light on modes of transmission and potential preventive strategies. Methods: We examined the records of patients diagnosed with melioidosis at the Microbiology Laboratory of Mahosot Hospital in Vientiane, Laos, between October, 1999, and August, 2015, and all patients with culture-confirmed melioidosis presenting to the Angkor Hospital for Children in Siem Reap, Cambodia, between February, 2009, and December, 2013. We also examined local temperature, humidity, precipitation, visibility, and wind data for the corresponding time periods. We estimated the B pseudomallei incubation period by examining profile likelihoods for hypothetical exposure-to-presentation delays. Findings: 870 patients were diagnosed with melioidosis in Laos and 173 patients were diagnosed with melioidosis in Cambodia during the study periods. Melioidosis cases were significantly associated with humidity (p<0·0001), low visibility (p<0·0001), and maximum wind speeds (p<0·0001) in Laos, and humidity (p=0·010), rainy days (p=0·015), and maximum wind speed (p=0·0070) in Cambodia. Compared with adults, children were at significantly higher odds of infection during highly humid months (odds ratio 2·79, 95% CI 1·83–4·26). Lung and disseminated infections were more common during windy months. The maximum likelihood estimate of the incubation period was 1 week (95% CI 0–2). Interpretation: The results of this study demonstrate a significant seasonal burden of melioidosis among adults and children in Laos and Cambodia. Our findings highlight the risks of infection during highly humid and windy conditions, and suggest a need for increased awareness among at-risk individuals, such as children. Funding: Wellcome Trust.

Published in The Lancet Planetary Health

ISSN: 2542-5196 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Geography. Anthropology. Recreation: Environmental sciences
Website: http://www.thelancet.com/journals/lanplh/issue/current

About the journal