Don’t forget malaria

POOR specimen collection and limited availability of medication could hinder malaria diagnosis and treatment, but experts say doctor awareness and communication are bigger problems.

A Perspectives article, published in the MJA, discussed potential obstacles to malaria diagnosis and hypnozoite eradication in Australia that may be putting patients at risk. (1)
    
The authors recommended malaria be considered for any patient with a history of travel to an endemic area who presented with fever, even if they had used prophylaxis.

When malaria was suspected, blood should be collected immediately on presentation, and delivered to the laboratory within an hour of collection. Both thick and thin film microscopy should be requested, the authors wrote.

They said that currently there was no consensus on the correct timing and number of specimens needed to exclude a diagnosis of malaria. While it appeared a single collection was usually sufficient, further specimen collections taken shortly after the onset of febrile paroxysms could be necessary for the detection of Plasmodium falciparum malaria.

The authors highlighted that “infection with relapsing species of malaria (P. vivax and P. ovale) requires eradication of hypnozoites from the patient’s liver using primaquine”. However, the medication was erratically available in Australia and not covered under the Pharmaceutical Benefits Scheme (PBS).

To overcome these obstacles to diagnosis and hyponozoite eradication, the authors wrote that it was important that doctors had the correct specimen-collection and treatment protocols readily available.

Professor James McCarthy, senior researcher in clinical tropical medicine at the QIMR Berghofer Medical Research Institute in Queensland, told MJA InSight that despite the article’s assertion that more Australians were travelling to endemic areas, the latest international figures on malaria prevalence rates were encouraging.

The World Malaria Report released last week showed the global incidence of malaria had actually fallen 30% between 2000 and 2013, mainly due to the expansion of malaria treatments. (2)

Professor McCarthy said that in Australia malaria was still relatively rare, with the majority of cases occurring in the Torres Strait region, but he warned that doctors should be conscious of travellers and fly-in, fly-out workers as at-risk groups.

He did not believe that diagnostic protocol and treatment availability were significant problems in Australia, but thought doctor–patient communication could be improved.

“The bigger issue is it that when a patient presents with a fever, doctors need to think to ask them about their travel history, and patients also need to tell their doctors about their travelling.”

Professor McCarthy also did not agree with the article’s suggestion that primaquine should be subsidised under the PBS.

“There is no licensed manufacturer of primaquine in Australia, so we have to get this medication through the Special Access Scheme. Covering [primaquine] under the PBS would not increase the use of this medication, because it wouldn’t solve the main problem of supply.”

In cases where primaquine or any other antimalarial medication was used, Professor McCarthy advised that patients should “always be referred to a specialist or teaching hospital to make sure the treatment is given correctly”.

Professor Louis Schofield, director of the Australian Institute of Tropical Health and Medicine in Queensland, agreed that subsidising primaquine under the PBS would not alter the baseline of treatment success in Australia, but emphasised the importance of all at-risk patients receiving prophylaxis.

To increase its effectiveness, he recommended that doctors ensure prophylaxis was tailored for patients according to where they were travelling. “If they’re travelling to a region with a particularly high incidence rate, their prophylactic treatment has to reflect this.”

Dr Maxine Whittaker, executive director of the Pacific Malaria Initiative Support Centre, told MJA InSight it was crucial for clinicians to keep updated on which regions were experiencing epidemics of tropical diseases to make sure their patients were prepared.

Dr Whittaker said the World Malaria Report indicated that parasites were becoming resistant to some antimalarial medications and this meant doctors must be mindful of giving patients vital practical advice.

“The most important information doctors can tell patients are ways to prevent mosquito bites in the first place”, she said, saying these included using insect repellent, sleeping under a bed net and wearing clothes that covered ankles and arms.

She also called for a national effort to make doctors more aware of malaria as a potential diagnosis.

“Because malaria was eradicated from Australia in 1982, many doctors have never seen what malaria looks like in a patient, so it is not the first diagnosis that comes to mind.

“We need to ensure doctors know what to look for and what to ask their patients”, Dr Whittaker said.
 

1. MJA 2014; 201: 630-631
2. WHO; Factsheet on the World Malaria Report 2014

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