25 July 2011 (Monday) - Cryptic Malaria

Usually the source of a malarial infestation is patently obvious. Occassionally it’s not so obvious. I found a link that gave some possible sources of malaria that might not be quite so readily apparent.

“Runway” Malaria

A plane stopping over in a malarious country might only stop for refuelling, but that delay might be enough for an infected mosquito to get aboard. Similarly there may well be infected mosquotos on a plane which, although travelling between “safe” airports, has relatively recently been in a malarious zone.
Or a patient might not realise that his holiday destination was a malarious one.

Or the unfortunate patient might never have actually been near a plane – a mosquito might be brought home in baggage and then infect someone on arrival at home.

“Late onset”

The onset of symptoms of malaria might take some time. Some eight per cent of ovale and vivax cases don’t become apparent for up to a year after patients returning home.

There would seem to be some connection with various ethnic groups and also with haemoglobinopathies in the delay of malarial symptoms.

“Person to Person contact”

Incredibly rare, but there is suspicion of this having happened in rare cases, and there has been documented cases of malarial infestation in medical staff following a needlestick injury.

“UK Malaria”

Somewhat worrying for me is the fact that the Anopheles mosquito (the one that carries malaria) lives on the Romney Marsh – an area of wetland not ten miles from my house. It is possible that an outbreak of malaria there some ninety years ago was due to local mosquitoes carrying malaria from infected ex-soldiers (who fought in the Mediterranean in World War One) to healthy individuals.

For all that unexplained malaria is incredibly rare, one needs to think outside the box – with international travel becoming more and more common, malarial infestations need to be borne in mind.

All of which brings us to today’s case: unexplained lethargy and fever turned out to be a case of P. falciparum. The G.P. assured us the patient had not holidayed anywhere recently. Was he sure? Yes. On admission the patient turned out to be a soldier who had recently been stationed in Malaria-Land. And so the patient had been true to his word – he hadn’t holidayed anywhere malarious. He’d worked there. A subtle distinction…..