9 December 2005

Malaria deaths in travellers returning from The Gambia

The Health Protection Agency (HPA) has reported a series of six cases of falciparum malaria in British travellers recently returned from The Gambia [1]. Two cases are known to have died, and two more are seriously ill. The cases, aged between 31 and 61 years, all became ill after returning to the United Kingdom (UK) in November 2005.  Five had been on holidays of one to two weeks, all in resorts within 20km of the Atlantic coast, with some cases having been on fishing or bird-watching excursions.  The sixth case had visited The Gambia several times on business and had travelled a little further inland than the other cases. All of the cases had taken either no or inadequate malaria chemoprophylaxis. 

The Gambia is a popular ‘winter sun’ destination for UK travellers, who account for nearly half of all tourists visiting this country [2] (around 30,000 in 2004).  It is a country where malaria is highly endemic, with year-round transmission and over 100,000 cases reported annually in residents [3].  Plasmodium falciparum is the commonest cause of malaria seen in The Gambia. Data from the HPA Malaria Reference Laboratory (MRL) shows that falciparum malaria accounts for over 90% of cases in travellers returning from The Gambia and that 4 in 100 of such cases between 2000 and 2004 were fatal.  Another cluster of cases were reported in December 2003 associated with late bookings to The Gambia [4]. Although the annual number of malaria cases in travellers returning from The Gambia has decreased over the last six years, the case fatality rate has increased and most cases did not take adequate chemoprophylaxis.

There is significant resistance to chloroquine in The Gambia, so this treatment, available over the counter in some pharmacies, should not be used as chemoprophylaxis [5].  Prescription-only malaria chemoprophylaxis should be taken for visits to The Gambia. Current guidelines on chemoprophylaxis for malaria prevention are available at http://www.hpa.org.uk/cdph/issues/CDPHvol6/No3/6(3)p180-99.pdf . Other important preventive measures include insect bite avoidance through suitable clothing, insect repellents and bed-nets.

Travellers to malaria endemic areas need to seek medical advice before travel. Chemoprophylactic regimes are often prescription-only medicines and may have to be started up to three weeks before departure. Travellers booking holidays at very short notice may not leave themselves time to make the necessary arrangements to protect themselves. The Federation of Tour Operators and Association of British Travel Agents have been informed about the recent cases.  They are taking steps to alert their members about this issue, and the need to remind all travellers to malarious areas to seek medical advice prior to departure.

Healthcare professionals should always take a travel history and consider a diagnosis of malaria in anyone with a fever/flu-like illness. They should also be aware that the absence of fever in an ill patient does not exclude the diagnosis of malaria. If the travel history includes travel to a malarious area in the past year, blood film examination should be performed without delay.

Malaria is a notifiable disease.  All malaria cases should also be reported to the HPA Malaria Reference Laboratory, with reporting forms available by downloading from the MRL website http://www.malaria-reference.co.uk, or from Marie Blaze at Marie.Blaze@lshtm.ac.uk.

References

1. Health Protection Agency. Malaria deaths in travellers returning from The Gambia. Commun Dis Rep CDR Wkly [serial online] 2005; 15 (49): news. Available at http://www.hpa.org.uk/cdr/archives/2005/cdr4905.pdf.

2. World Tourism Organization (WTO). Yearbook of tourism statistics. 2002. Madrid: WTO; 2002.

3. World Health Organization Regional Office for Africa (AFRO) Malaria country profiles: The Gambia.  AFRO website [online] 2004 [cited 8 December 2005]. Available at <http://www.afro.who.int/malaria/country-profile/gambia.pdf>.

4. Health Protection Agency.  Consequences of failure to use malaria prophylaxis in The Gambia. Commun Dis Rep CDR Wkly [serial online] 2003 [cited 8 December 2005]; 13 (49): news.  Available at <http://www.hpa.org.uk/cdr/archives/2003/cdr4903.pdf>.

5. Moore DAJ, Grant AD, Armstrong M, Stümpfle R, Behrens R.  Risk factors for malaria in UK travellers.  Trans R Soc Trop Med Hyg 2004; 98: 55-63.