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Prevention of malaria is based on personal vector-control measures (PVCMs) to avoid mosquito bites at night and chemoprophylaxis if justified by the risk of contracting the disease. The most effective PVCM is the use of insecticide-treated mosquito nets. The decision to prescribe chemoprophylaxis, mainly to prevent Plasmodium falciparum infection, depends on the benefit-risk ratio. Overall, the risk of contracting malaria is 1,000-fold lower during a stay in the tropical regions of Asia or the Americas than in sub-Saharan Africa. For "conventional" stays (less than one month with nights spent in urban areas) in low-risk settings in tropical Asia and America, the risk of being infected with Plasmodium parasites (≤1/100,000) is equivalent or lower than that of experiencing serious adverse effects caused by chemoprophylaxis. Preventive medication is therefore no longer recommended. By contrast, in other settings and particularly in sub-Saharan Africa, chemoprophylaxis is the most effective measure against malaria. However, it is worth noting that no single preventive measure provides full protection. Regardless of the level of risk or chemoprophylaxis-related indication, protection against mosquito bites and rapid management of febrile illness after returning from an endemic area are also critical to prevent malaria. Finally, migrants of sub-Saharan origin visiting friends and relatives in their country of origin form a high-risk group who should be recommended chemoprophylaxis in the same way as any other travelers-with a preference for the least expensive molecules (doxycycline).

Since the 2007 French guidelines on imported Falciparum malaria, the epidemiology, treatment, and prevention of malaria have changed considerably requiring guidelines for all Plasmodium species to be updated. Over the past decade, the incidence of imported malaria has decreased in all age groups, reflecting the decrease in the incidence of malaria in endemic areas. The rates of severe pediatric cases have increased as in adults, but fatalities are rare. The parasitological diagnosis requires a thick blood smear (or a rapid immunochromatographic test) and a thin blood film. Alternatively, a rapid antigen detection test can be paired with a thin blood film. Thrombocytopenia in children presenting with fever is highly predictive of malaria following travel to a malaria-endemic area and, when detected, malaria should be strongly considered. The first-line treatment of uncomplicated P. falciparum malaria is now an artemisinin-based combination therapy (ACT), either artemether-lumefantrine or artenimol-piperaquine, as recommended by the World Health Organization in endemic areas. Uncomplicated presentations of non-falciparum malaria should be treated either with chloroquine or ACT. The first-line treatment of severe malaria is now intravenous artesunate which is more effective than quinine in endemic areas. Quinine is restricted to cases where artesunate is contraindicated or unavailable. Prevention of malaria in pediatric travelers consists of nocturnal personal protection against mosquitoes (especially insecticide-treated nets) combined with chemoprophylaxis according to the risk level.

Introduction Le vaccin de la fievre jaune (FJ) est contre-indique chez les patients ayant une immunosuppression. Malgre l’absence de donnees, les recommandations sanitaires pour le voyageur autorisent cette vaccination chez les patients drepanocytaires traites par hydroxycarbamide (HC). L’objectif de cette etude etait d’evaluer la tolerance et l’efficacite du vaccin FJ chez des enfants drepanocytaires traites ou non par HC. Materiels et methodes Il s’agit d’une etude prospective realisee entre mars 2016 et juillet 2017. Tous les enfants drepanocytaires de mois de 18 ans, traites ou non par HC et recevant un vaccin FJ dans un des 3 centres de vaccination du voyage de l’etude ont ete inclus. La tolerance a ete evaluee par un entretien telephonique a 15 jours de l’injection. L’efficacite a ete evaluee a environ 6 mois par une serologie FJ > 5 en methode PRNT80. Le test Mann–Whitney a ete utilise pour les comparaisons. Resultats Au total, 54 enfants, âge median de 7.6 ans [2,9 ; 12,4], sex-ratio M/F 0,61, ont ete inclus. Tous recevaient une primo-vaccination. Dix-sept sur 54 etaient traites par HC. Les enfants HC + etaient plus âges que les enfants HC − (6,8 vs 9,5 ans, p = 0,0015), plus souvent sous programme d’echange transfusionnel (17 vs 3 %, p = 0,006) et avaient des lymphocytes totaux plus bas (3,3 vs 4,9 G/L, p = 0,014) que les enfants HC −. Quarante-trois pourcent des enfants ont eu des effets indesirables post-vaccination, tous de grade I/II. Les plus frequents etaient une douleur au point d’injection (24 % des patients) ou une fievre (17 % des patients). Globalement, la frequence des effets indesirables etait identique dans les 2 groupes (37 % dans le groupe HC − vs 57 % dans le groupe HC + , p = 0,15). La proportion de seroconversion FJ etait plus faible dans le groupe HC + (85 %) par rapport au groupe HC − (100 %). Le titre d’anticorps median etait comparable dans les deux groupes (40 UI/mL). Conclusion La tolerance de la vaccination FJ semble satisfaisante chez les enfants traites par HC bien que la taille de notre effectif ne permette pas de conclure definitivement. Les enfants drepanocytaires sous HC ont toutefois une moins bonne reponse vaccinale. Un controle serologique est necessaire chez ces enfants afin de discuter la realisation d’une 2e dose de vaccin fievre jaune avant un nouveau depart en zone d’endemie.