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Background: During blood meal, the female mosquito injects saliva able to elicit an immune response in the vertebrate. This immune response has been proven to reflect the intensity of exposure to mosquito bites and risk of infection for vector transmitted pathogens such as malaria. The peptide gSG6-P1 of An. gambiae saliva has been demonstrated to be antigenic and highly specific to Anopheles as a genus. However, the applicability of gSG6-P1 to measure exposure to different Anopheles species endemic in the Americas has yet to be evaluated. The purpose of this pilot study was to test whether human participants living in American countries present antibodies able to recognize the gSG6-P1, and whether these antibodies are useful as a proxy for mosquito bite exposure and malaria risk., Methods: We tested human serum samples from Colombia, Chile, and the United States for the presence of IgG antibodies against gSG6-P1 by ELISA. Antibody concentrations were expressed as delta optical density (ΔOD) of each sera tested in duplicates. The difference in the antibody concentrations between groups was tested using the nonparametric Mann Whitney test (independent groups) and the nonparametric Wilcoxon matched-pairs signed rank test (dependent groups). All differences were considered significant with a P < 0.05., Results: We found that the concentration of gSG6-P1 antibodies was significantly correlated with malaria infection status and mosquito bite exposure history. People with clinical malaria presented significantly higher concentrations of IgG anti-gSG6-P1 antibodies than healthy controls. Additionally, a significant raise in antibody concentrations was observed in subjects returning from malaria endemic areas., Conclusion: Our data shows that gSG6-P1 is a suitable candidate for the evaluation of exposure to Anopheles mosquito bites, risk of malaria transmission, and effectiveness of protection measures against mosquito bites in the Americas.

Background: Traveling to tropical regions is related to increased health risks. Travelers' diarrhea is the most frequent health problem, but the range of travel-related diseases also includes potential life-threatening diseases such as malaria. The actual risk of European travelers acquiring specific infectious diseases and other hazards in the tropics is to a large extent unknown and is therefore often adopted from that of the indigenous population. The objective of this study was to elucidate the risk for travel-related diseases, symptoms, and accidents in a population of Europeans who travel to popular tourist destinations., Methods: From July 2003 to June 2004, 794 travelers consulting the travel clinic of the Berlin Institute of Tropical Medicine were recruited for a questionnaire-based observational study before traveling to Kenya, Tanzania, Senegal, the Gambia, India, Nepal, Thailand, or Brazil., Results: Overall, illness was reported by 42.9% of travelers, with 10.2% reporting more than one adverse health event. Most frequently gastrointestinal symptoms were noted (34.6%), followed by respiratory symptoms (13.7%). More than 5% experienced an accident. Travel to the Indian subcontinent nearly doubled the risk of becoming ill; travel to Thailand significantly decreased the risk. Additional risk factors were a long duration of staying abroad, young age, and traveling under basic conditions. Of all travelers, 80% did not follow the traditionally recommended dietary restrictions. Among travelers visiting malaria-endemic areas, 20% did not carry any antimalarial drugs with them, not continuous chemoprophylaxis or standby medication., Conclusions: Because of the rising travel activity, especially to tropical countries, the importance of qualified pretravel advice consultation is increasing. To improve the travelers' health, attention needs to be paid to individual risk factors, the prevention and therapy of travelers' diarrhea, malaria prophylaxis, management of respiratory illness, and personal safety.

Background The effect of clothing colour on the biting rates of different vector mosquito species is not well understood. Studies under tropical field conditions are lacking. This study aimed to determine the influence of clothing colours on mosquito biting rates in rural and suburban settings in West Africa. Methods We performed a simulated field study in a suburban and a rural site in Mali using Mosquito-Magnet traps utilizing CO2 and other attractants, which were covered with black, white, and black/white striped textile sheets covers. These targets operated continuously for 10 consecutive days with bright nights (around full moon) and 10 consecutive days with dark nights (around new moon). Trapped mosquitoes were collected and catch rates counted hourly. Mosquitoes were morphologically identified to the species complex level (Anopheles gambiae s.l. and Culex pipiens s.l.) or species level (Aedes aegypti). A subset of Anopheles specimens were further identified by molecular methods. Results Under bright-night conditions, An. gambiae s.l. was significantly more attracted to black targets than to white and striped targets; during dark nights, no target preference was noted. During bright nights, Cx. pipiens s.l. was significantly more attracted to black and striped targets than to white targets; a similar trend was noted during dark nights (not significant). For day-active Ae. aegypti , striped targets were more attractive than the other targets and black were more attractive than white targets. Conclusions The study firstly demonstrated that under field conditions in Mali, West Africa, mosquito catch rates were influenced by different clothing colours, depending on mosquito species and light conditions. Overall, light colours were least attractive to host-seeking mosquitoes. Using white or other light-coloured clothing can potentially reduce bite exposure and risk of disease transmission in endemic tropical regions. [ABSTRACT FROM AUTHOR]

We report a cluster of imported vivax malaria in three of five Chilean travelers returning from Peru in March 2015. The cluster highlights the high risk of malaria in the Loreto region in northern Peru, which includes popular destinations for international nature and adventure tourism. According to local surveillance data, Plasmodium vivax is predominating, but Plasmodium falciparum is also present, and the incidence of both species has increased during recent years. Travelers visiting this region should be counseled about the prevention of malaria and the options for chemoprophylaxis. [ABSTRACT FROM AUTHOR]