Understanding the knowledge and risk perception that individuals have of malaria is valuable when trying to understand attitudes and practices in the use of preventative measures. The study surveyed the UK general population to provide a background level of knowledge and attitudes and used the population who had previously travelled to a malaria-endemic region (28%, 548) as a comparator with a similarly sized departing passenger population of 500. The average malaria knowledge score of the general UK population who had not travelled to a malaria-endemic country, at 58.6, was significantly lower than in those who had previously travelled or who were travelling (63.8 and 70.7, respectively).
Knowledge, perception of malaria and its threat, and the use of chemoprophylaxis in departing passengers were assessed to determine possible influences on use of chemoprophylaxis. The main focus was on VFR's who were travelling to sub-Saharan Africa, as this is the group with the highest morbidity from malaria. The ages in the three groups were similar but black travellers and West Africa as a destination, were more frequent in the CAA group, as this was a destination targeted by the CAA surveyors. The source of pre-travel advice among CAA and IPSOS was similar (72 vs 74%) received advice from a professional source). Unexpectedly, the levels of knowledge in passengers using chemoprophylaxis were lower to those not using a drug regimen. Similarly, those travellers who had received professional pre-travel advice did not have a higher knowledge score than travellers who had not received advice or received advice through a non-professional source. The same phenomenon was noted in the non-travelling population, who overall, achieved lower knowledge scores.
Comparing travellers to three destinations in sub-Saharan Africa (Table 3), passengers to Kenya were predominantly (83%) travelling for leisure. The majority of leisure travellers to Ghana and Nigeria were VFRs (74%) while only one third of those travelling to Kenya were VFRs. The mean knowledge score in those using chemoprophylaxis was 69 for the three destinations and higher (77.5, 74.2 and 74.1) in those not using chemoprophylaxis. The perception of threat from malaria was similar in the three groups travelling, with 38% of passengers to Ghana, 46% to Nigeria and 51% to Kenya believing malaria often killed.
When asked about use of chemoprophylaxis, the majority of passengers to Ghana (74%) and Kenya (71%) were taking an effective regimen. However, among passengers to Nigeria, which included 32% travelling on business, only 50% were using any chemoprophylaxis and only 38% used an effective regimen. Despite having similar levels of knowledge and equal understanding of the seriousness of malaria, significantly fewer Nigerians were using preventative drugs for malaria than other destination passengers. There is some evidence that as an alternative to chemoprophylaxis, some VFR travellers choose to self-treat their fever symptoms with anti-malarial drugs either purchased before or during travel.[10,11] This practice of self-treatment is not recommended in the UK national guidelines for travel to high risk regions in sub-Saharan Africa, but may be adopted by semi-immune travellers as an alternative to taking chemoprophylaxis. Nigerians travelled more frequently than passengers to Kenya and Ghana with 72% having made one or more trips to Nigeria in the previous 12 months. Forty percent of Nigerians had not received professional pre-travel advice before the current journey, nearly double that of visitors to Ghana (22%) and Kenya (23%).
The proportion of travellers accessing health care pre-travel in this study represents an unbiased sample of departing travellers and their prophylaxis use. Many other studies of malaria prophylaxis compliance have been based on travellers with malaria or travellers departing from endemic countries[10,12] although some have questioned departure lounge passengers.
The study's assessment of knowledge was based around a range of 22 questions that had weighted responses. It is possible that questions may not have been probing or detailed enough or the weighting not adjusted to provide the sensitivity to define knowledge accurately. The sample sizes of travellers to sub-Saharan regions were large enough for sub-analysis but there were a number of other countries visited in Southeast Asia, the Indian Subcontinent and South America whose numbers were too small to analyse separately.
These findings suggest that malaria knowledge, perceived threat, previous travel experience and source (quality) of pre-travel advice are not important factors in predicting the use of chemoprophylaxis. Failure to obtain pre-travel advice may still be a contributory factor to non-use of chemoprophylaxis but not linked to knowledge of malaria or threat perception, (belief that malaria occasionally, often or always kills) which was similar in the three groups. Repeated travel to Nigeria was strikingly more frequent and may be an important influence in reducing chemoprophylaxis use.
In a European-wide departure survey of travellers to high-risk malaria regions, 56% were carrying malaria prophylaxis and 28% carried self-treatment for malaria. In this survey 52.1% had received pre-travel advice although only 31.4% of VFRs had received advice. The majority of advice (80%) was from a health professional with one-quarter of respondents obtaining advice from the internet and/or friends. A Spanish departure survey reported that 64% of travellers to sub-Saharan Africa were using chemoprophylaxis. Over 83% of respondents had sought pre-travel advice and travellers who had visited the same region previously were three times less likely to seek health information than first-time travellers. Schilthuis interviewed Nigerians and Ghanaians living in the Netherlands and reported that only 16% of the VFRs had adequate knowledge of malaria. Departing Dutch VFR travellers from Schiphol Airport were questioned on pre-travel preparation and use of anti-malaria measures and malaria knowledge; 74% had correct malaria knowledge, a similarly high knowledge score (71) as in this study's travellers from Heathrow. Dutch passengers' use of anti-malaria measures was overall lower (31.9%) than that reported by all UK departing passengers (61%) and matched the proportion of Nigerian travellers 'use of an effective chemoprophylaxis (38%), although the assessment of prophylaxis usage was defined differently across the two studies, and findings may not be directly comparable. These two studies highlight that malaria knowledge and risk awareness combined with receipt of pre-travel advice does not necessarily result in compliance with malaria preventative measures.
Neave and colleagues highlighted this paradox, where for many VFRs the actual malaria risk did not correlate to personal perceived risk of developing malaria, and suggested that chemoprophylaxis use is influenced by perceived susceptibility, previous experience of malaria, cost of chemoprophylaxis, threat of fatality from malaria and peer pressure. This study finds that perception of fatality from malaria does not correlate with uptake, as Nigerians and Ghanaians have the same perceived threat but very different chemoprophylaxis use. Cost of chemoprophylaxis has been argued as a major barrier to prophylaxis uptake, but recent evidence from two London communities is that, despite availability of free chemoprophylaxis for travellers, there was marginal reduction in imported malaria in VFR travellers when compared to a non-subsidized community.
Malar J. 2013;12(461) © 2013 BioMed Central, Ltd.