Half the 1,378 imported malaria cases reported in the United Kingdom in 2012 occurred among London residents, with the large majority acquired during travel to Africa to visit family in their country of origin, says a report from Public Health England (PHE).
A common belief among people born in malaria-endemic countries, says a PHE press release, may be that they assume they have natural immunity to the disease and so do not need prophylaxis when traveling there. In reality, immunity wears off quickly once a person leaves an endemic area, the release says.
Estimates of the London population born abroad were nearly 37% for 2011, according to the PHE report. Imported malaria cases in the city numbered 676 in 2012, a rate of 8 per 100,000 residents. This represents a decline in incidence compared with 2011, which was reflected across the United Kingdom, but is still of concern since the disease is highly preventable, the PHE said.
From 2000 to 2012, 88% of imported cases in London were acquired in sub-Saharan Africa, says the report. Nigeria was the most common destination, accounting for 45% of the imported London cases over that period. Fully 80% of infected persons for whom information was available had not taken any prophylaxis before travel. Summer travel was common, which is the high-transmission rainy season in West Africa.
The largest portion of the 2012 London cases were in residents of southeast London, particularly Southward and Greenwich. It is likely, according to the release, that a large number of persons in those areas are of black African ethnicity so may be more likely to travel to Africa.
Interventions, including pretravel education and chemoprophylaxis, can prevent the disease and should be encouraged among those traveling to malaria-endemic areas, particularly Nigeria, advises the report.