The risk of malaria in travelers to India.
BACKGROUND
Several countries have reported a decline in malaria cases imported by travelers returning from India.


METHODS
We collected data on imported malaria for the period 1992 to 2005 from nine countries. Traveler statistics denominator data were obtained from the Indian Ministry of Tourism.


RESULTS
The malaria case numbers declined from 93 cases per 100,000 travelers in 1992 to 19 cases per 100,000 travelers in 2005. The proportion of Plasmodium falciparum decreased steadily throughout the years. The proportion of Plasmodium vivax accounts for more than 80% of all cases of malaria in travelers to India. Deaths due to malaria were rare; only the UK and the United States reported deaths, a total of 16, between 1992 and 2005. The high-risk areas for malaria in India can be clearly identified using endemic malaria data. High-risk states are Chhattisgarh, Orissa, Jharkhand, West Bengal, Goa (mainly P vivax), and the states east of Bangladesh.


CONCLUSIONS
The decreasing incidence of malaria in travelers to India and the high proportion of P vivax support the current change in guidelines in some European countries advocating the use of the standby emergency self-treatment strategy or bite precautions plus awareness of risk instead of chemoprophylaxis. Otherwise in high-risk states, chemoprophylaxis should still be considered particularly in high-transmission seasons.
Schmid
Sabine
S
Center for Travel Medicine, WHO Collaborating Center for Travelers' Health, Institute for Social and Preventive Medicine, University of Zurich, Zurich, Switzerland.
Chiodini
Peter
P
Legros
Fabrice
F
D'Amato
Stefania
S
Schöneberg
Irene
I
Liu
Conan
C
Janzon
Ragnhild
R
Schlagenhauf
Patricia
P
D000328:Adult; D000818:Animals; D005060:Europe / Q000453:epidemiology; D005260:Female; D005843:Geography; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000517:prevention & control; D016780:Malaria, Vivax / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000254:growth & development; D010966:Plasmodium vivax / Q000254:growth & development; D017410:Practice Guidelines as Topic; D012307:Risk Factors; D017678:Sex Distribution; D014195:Travel; D006113:United Kingdom / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D014944:World Health Organization