Respiratory physicians have been warned to have a high index of suspicion for infection with Burkholderia pseudomallei – the cause of melioidosis – in patients with cystic fibrosis who have travelled in northern Australia or South-East Asia.
Respiratory physician Dr James Geake, from the Lyell McEwin Hospital in Adelaide, and colleagues identified 25 culture-confirmed cases of infection occurring in CF patients worldwide, of which 10 were thought to have been contracted in northern Australia.
Writing in BMC Pulmonary Medicine, they said melioidosis is often reported in people returning from travel to an endemic region.
“At-risk tourists include those with diabetes and CF exposed to soil and surface water or monsoonal storms where aerosolisation of B. pseudomallei may occur,” they said.
“Generally patients who survive infection clear the organism and rarely relapse following an adequate duration of therapy.”
In 10 of the patients with CF cases the organism was found incidentally on routine sputum surveillance and in 14 cases it was found when investigating symptoms of increased cough and sputum. There was no information available on one patient’s presentation.
Systemic features – fever, weight loss or deteriorating glycaemic control in those who also had diabetes – were reported in 10 patients.
“New radiological changes were documented in eight patients, with patchy areas of consolidation being the most common abnormality,” Dr Geake said.
A total of 19 patients developed chronic infection lasting at least one year and up to 11 years. In 14 cases this was thought to have accelerated the decline of their pulmonary status, with features including an increased frequency of exacerbations, lower response to intravenous antibiotics and faster loss of lung function.
Three patients had lung transplants after being infected: two are alive two and 10 years later and one died after five years. All continued to have low-grade infection with B. pseudomallei.
“Eradication of B. pseudomallei infection should be attempted for CF patients when this pathogen is first isolated,” Dr Geake said.
“Initial intravenous therapy should include a minimum of two weeks intravenous ceftazidime (and or meropenem if severe sepsis).
“We also recommend addition of oral/intravenous trimethoprim/sulfamethoxazole from the onset of therapy and this should continue where possible for three months.”
“Travel should be avoided to northern Australia or south-east Asia during the monsoonal season, with particular care to minimise exposure to wet season soils and rain in resident patients.”