Epidemiology and clinical features of vivax malaria imported to Europe: Sentinel surveillance data from TropNetEurop

Background: Plasmodium vivax is the second most common species
among malaria patients diagnosed in Europe, but epidemiological and
clinical data on imported P. vivax malaria are limited. The
TropNetEurop surveillance network has monitored the importation of
vivax malaria into Europe since 1999. Objectives: To present
epidemiological and clinical data on imported P. vivax malaria
collected at European level. Material and methods: Data of primary
cases of P. vivax malaria reported between January 1999 and
September 2003 were analysed, focusing on disease frequency,
patient characteristics, place of infection, course of disease,
treatment and differences between network-member countries.
Results: Within the surveillance period 4,801 cases of imported
malaria were reported. 618 (12.9%) were attributed to P. vivax.
European travellers and immigrants were the largest patient groups,
but their proportion varied among the reporting countries. The main
regions of infection in descending order were the Indian
subcontinent, Indonesia, South America and Western and Eastern
Africa, as a group accounting for more than 60% of the cases.
Regular use of malaria chemoprophylaxis was reported by 118
patients. With 86 (inter-quartile range 41-158) versus 31 days
(inter-quartile range 4-133) the median symptom onset was
significantly delayed in patients with chemoprophylaxis (p <
0.0001). Common complaints were fever, headache, fatigue, and
musculo-skeletal symptoms. All patients survived and severe
clinical complications were rare. Hospitalization was provided for
60% and primaquine treatment administered to 83.8% of the patients,
but frequencies varied strongly among reporting countries.
Conclusions: TropNetEurop data can contribute to the harmonization
of European treatment policies.