Table 2 Patterns of misconceptions around chemoprophylaxis for malaria, as identified in qualitative analysis of travel blogs

English-language blog

 Although the information offered by the authors on chemoprophylaxis was correct, topics generated by visitors often contained incorrect advice or comments that could discourage the use of antimalarial prophylaxis. Frequently, these comments were not refuted by the blog authors, perhaps due to their fear of losing followers

 The posts address the financial cost of chemoprophylaxis pills for the traveller, quantifying these from a cost-benefit point of view but without a scientific basis

 It is common to find numerous self-referenced links to the website itself on various aspects of malaria (risk areas, pregnancy, use of repellents …) instead of links to official health websites.  It seems that more value is placed on attracting traffic to the site (SEO) than providing accurate or serious travel advice, or perhaps bloggers seek to avoid projecting an image that is too serious

 Bloggers often make subjective comments with a negative or neutral tone about chemoprophylaxis, for example: “If there is no other choice, we will take it,” “We have not seen a mosquito the whole trip,” “In Nepal we found a traveller taking chemoprophylaxis at 2800 meters, what crazy doctor advised her?” This type of comment can generate or contribute to reluctance to start any prophylaxis

Spanish-language blogs

 Twelve recommended “the malaria vaccine” for travel, showing clear confusion with the concept of immunization versus chemoprophylaxis.

 The dosage of antimalarials in many cases was wrong or their indication was outdated (for example, they spoke of using chloroquine in areas of current resistance).

 The side effects of chemoprophylaxis were described in 44 blogs, described in language such as: “poison,” “serious complications,” “aggressive pills,” or “psychotic attack.”

 Some of the blogs recommended products based on vitamin B or repellants and devices against mosquitoes of dubious or scientifically unproven efficacy.