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

Abstract

SummaryBackgroundBurkholderia 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.MethodsWe 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.Findings870 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).InterpretationThe 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.FundingWellcome Trust.

Description of two fatal cases of melioidosis in Mexican children with acute pneumonia: case report

“…humidity > 80%, temperature between 68 and 86 °F, and rainfall), as well as potential exposures to contaminated sources. Although melioidosis is more frequent in adults, children and adolescents may have a high risk of being infected by B. pseudomallei , due to the likelihood of environmental exposure, either by inhalation of the pathogen or through wounds while swimming in contaminated water [ 27 , 28 ]. This was probably the case with these two children, because B. pseudomallei was found in water and sediment in the area where the children used swam and neither had diabetes as a risk factor.…”

Presence of Burkholderia pseudomallei in the ‘Granary of Myanmar’

“…In recent years, heavy rain, flooding and cyclones have occurred regularly in Myanmar. The areas included in this study regularly experience flooding and cyclones, conditions which are likely to predispose to B. pseudomallei infection [43,44,45].…”

The first imported case of melioidosis in a patient in central China

“…To type the identified isloate, multilocus sequence typing ( MLST ) was conducted and it was turned out that this isolate can be grouped as sequence type 46 (ST46) (https://pubmlst.org/) (Figure 1(D)), which is consistent with those isolates that originated from Laos [7]. To further define the relatedness of ST46 isolates, whole-genome sequencing was performed.…”