[Personal protection measures against blood-sucking insects and ticks].

Blood-sucking arthropods are major vectors of various pathogens like viruses, bacteria, protozoa and nematodes. Preventing exposure to the vector is imperative especially when vaccine and prophylactic treatments are not available. Personal protection measures (PPM) are essential and often the only means available when dealing with blood-sucking disease transmitting arthropods. Awareness of the risk in the specific areas of travel is the first step to be taken before and while traveling. PPM include preventive personal behavior, suitable clothing, application of insect repellents to the skin, the use of space repellents, impregnation of clothing, camping gear and bed nets and, when necessary, ground spraying of insecticides. The registered and recommended active ingredients for skin application are Deet, picaridin (icaridin), p-menthane-3,8-diol (PMD) and IR3535. Volatile pyrethrins are used as space repellents while pyrethroids, especially permethrin, are employed for impregnation and for ground spraying. It is recommended to purchase only products registered in Israel or other developed countries. These products should have a detailed label specifying the concentration of the active ingredient, application instructions and the duration of protection.

Patterns of insecticide resistance in larval Culex pipiens populations in Israel: dynamics and trends.

Resistance to insecticides of larval Culex pipiens populations in Israel has been monitored for ten years and the results were used for control planning. The insecticides tested were the organophosphates chlorpyrifos, fenthion, and temephos and the pyrethroids permethrin and cypermethrin. Over the years the relative resistance (R/R) values to chlorpyrifos in most populations tested were between 200-400, with records of up to 700 R/R. Practically no susceptible populations were found and the compound has been withdrawn from use, resulting in a decrease in the relative resistance values. In 1996 when fenthion was reintroduced, no resistant populations were found, but in the following years significant resistance appeared in an increasing number of populations with values lower than recorded for chlorpyrifos but still high (up to 100 R/R). All populations tested were found to be susceptible to temephos and accordingly the compound was reintroduced in 2002. Over the ten years, no significant resistance to cypermethrin was found in the majority of the populations tested, while a trend of increased resistance to permethrin was noted with a few records of >1000 R/R. The results demonstrate the importance of continuous monitoring of insecticide resistance for efficient mosquito control. Alternative insecticides and methods of control are discussed.

[The reemergence of malaria in Israel?].

Worldwide, malaria is the most prevalent vector-borne disease, endemic or hyperendemic in more than 100 countries. The disease is transmitted to humans by the bite of an infected female Anopheles mosquito, a protozoan of the genus Plasmodium with a life cycle split between man (the vertebrate host) and the mosquito vector. Since the 1960s, Israel has been considered a malaria free country, despite a substantial number of imported cases each year (mainly P. falciparum originating in Africa and P. vivax). Between 60-100 imported malaria cases are registered annually due to young people traveling to endemic countries and immigration from sub-Saharan Africa. However, since successful malaria control was achieved without the elimination of local Anopheles populations, concern about the possibility of renewed malaria transmission in Israel is increasing. Among travelers to malaria endemic countries, the disease can usually be prevented with prophylactic use of antimalarial drugs and strict measures to prevent mosquito bites. If, on their return, travelers become ill, they should seek prompt medical attention and inform their physician which countries they have visited. For their part, physicians should not fail to elicit travel history as part of the routine fever workup. Finally, intensive surveillance and control of the mosquito populations is also imperative to diminish the risk of reestablishment of malaria transmission.