naphthoquinones and Insect-Bites-and-Stings

The prophylactic antimalarial activity of atovaquone was determined in a randomized, double-blind, placebo-controlled study of healthy volunteers who were challenged by the bite of Plasmodium falciparum-infected Anopheles stephensi. Subjects were randomly assigned to one of three groups: six received seven daily doses of 750 mg of atovaquone, starting the day before challenge; six received a single dose of 250 mg of atovaquone the day before challenge; and four received placebo. Polymerase chain reaction- and culture-confirmed parasitemia developed in all four placebo recipients, but in none of the drug recipients, indicating that either of the atovaquone regimens provides effective prophylaxis (P = 0.005). However, in low-dose recipients, the drug levels by day 6.5 were profoundly subtherapeutic, indicating that parasites were eliminated prior to the establishment of erythrocytic infection. Atovaquone thus protects non-immune subjects against mosquito-transmitted falciparum malaria, and has causal prophylactic activity.

Topics: Adolescent; Adult; Animals; Anopheles; Antimalarials; Atovaquone; Double-Blind Method; Humans; Insect Bites and Stings; Malaria, Falciparum; Middle Aged; Naphthoquinones; Parasitemia; Plasmodium falciparum; Polymerase Chain Reaction

Long-term travellers and expatriates are often non-compliant with malaria chemoprophylaxis due to a gradual neglect of the malaria risk combined with an unwillingness to take drugs for prolonged periods. The available regimes either have limited efficacy or are hampered by side effects, fears, cost and lack of data on long-term use. In order to prevent the dire consequences of malaria, we suggest tailoring the antimalarial strategy to the individual traveller. This requires balancing the risk of getting malaria, based on local transmission patterns, mosquito control and other factors, with the traveller's access to medical care and the options for chemoprophylaxis, the use of which in some cases may be limited to the rainy season or periods of travel to high-risk areas.

Topics: Antimalarials; Atovaquone; Chloroquine; Counseling; Doxycycline; Drug Combinations; Humans; Insect Bites and Stings; Malaria; Mefloquine; Mosquito Control; Naphthoquinones; Proguanil; Risk Assessment; Risk Factors; Travel

To offer effective malaria chemoprophylaxis for travelers in a country, the physician must know the precise status of malaria there (frequency, resistance), determine the degree of exposure to mosquito bites, evaluate the precise clinical condition of the traveler, and improve the traveler's compliance with treatment by providing good information on potential side-effects. These side-effects, sometimes overemphasized in the media, lead to poor compliance, particularly after returning home, and, consequently, increase the risk of acquiring malaria. The recently approved Malarone could overcome these drawbacks. But its cost is high and its wide use could also lead to the emergence of resistant strains. Therefore, training professionals in travel medicine is important in malaria prevention and decrease the prescription of abusive or inaccurate prophylaxis (e.g., most tourists traveling in organized tours in Asia, with no stay in remote malaria endemic areas, do not need any prophylaxis). In addition, prevention of mosquito bites with repellents, impregnated bed nets, and indoor insecticide-dispensing devices is still an important tool for controlling malaria in travelers.

Topics: Animals; Antimalarials; Atovaquone; Child; Drug Administration Schedule; Drug Combinations; Drug Resistance, Multiple; Endemic Diseases; Female; Humans; Immunocompromised Host; Insect Bites and Stings; Malaria, Falciparum; Mosquito Control; Naphthoquinones; Patient Compliance; Pregnancy; Proguanil; Travel

Malaria is a life-threatening illness which can be particularly risk in children. This paper guides nurses who offer travel advice on the best approaches to take with parents. It is best to avoid travelling to areas affected by the disease at all. However, if people do travel, they should take prophylactic medication as well as other precautions to avoid being bitten by mosquitoes.

Topics: Animals; Antimalarials; Atovaquone; Chemoprevention; Child; Culicidae; Doxycycline; Drug Combinations; Humans; Insect Bites and Stings; Malaria; Mefloquine; Naphthoquinones; Proguanil; Travel