Assessment of acceptability and ease of use of atovaquone/proguanil medication in subjects undergoing malaria prophylaxis

A case of acute generalized exanthematous pustulosis caused by exposure to Atovaquone/proguanil

We present a returning traveler with acute generalized exanthematous pustulosis after atovaquone/proguanil prophylaxis. Diagnosis was confirmed with biopsy and allergy testing, symptoms resolved after steroid treatment. Atovaquone/proguanil prophylaxis is generally well tolerated, however, some patients may present severe adverse events that require prompt medical evaluation and treatment.

Compliance with Primary Malaria Chemoprophylaxis: Is Weekly Prophylaxis Better Than Daily Prophylaxis?

BACKGROUND

Chemoprophylaxis is an effective tool for individuals to minimize their risk of contracting malaria and serves an important public health role in preventing imported malaria. Yet, it is only effective if the traveller is fully compliant with the prescribed regimen. For many destinations, a choice of prophylactic agents is available, so historical compliance data can be helpful for both physicians and travellers to make an informed decision.

METHODS

We analyzed the historical self-reported compliance data for six chemoprophylactic agents currently recommended by CDC for primary malaria chemoprophylaxis by searching PubMed, Embase, CINAHL, Web of Science, and Scopus for observational studies reporting on travelers within the last 25 years. The quality of data was graded as "good" or "poor" using the NIH quality assessment tool for cohort and cross-sectional studies. Cumulative compliance data were compiled for all studies (gross compliance) and the subgroup of studies with "good" quality evidence (refined compliance). Subgroup analyses were performed for weekly vs daily administered regimens, between military and civilian travelers, and across each prophylactic agent.

RESULTS

Twenty-four eligible studies assessed compliance for mefloquine (n=20), atovaquone-proguanil (n=11), doxycycline (n=13), and chloroquine (n=3). No studies were found for primaquine or tafenoquine. Both gross and refined compliance were significantly better for weekly regimens than daily regimens (P<0.0001). Stopping chemoprophylaxis due to adverse events was significantly more for doxycycline (P<0.0001) compared to other drugs. Compliance was significantly worse in military travelers, but they were also more likely to be prescribed doxycycline.

CONCLUSION

Malaria chemoprophylaxis for a traveler should depend on prevailing resistance patterns at destination, current national guidelines, and patient preferences. However, when there is a choice, historical compliance data are useful to select a regimen that the traveler is more likely to comply with.

Factors Affecting Pre-Travel Health Seeking Behaviour and Adherence to Pre-Travel Health Advice: A Systematic Review

BACKGROUND

Recent years have seen unprecedented growth in international travel. Travellers are at high risk for acquiring infections while abroad and potentially bringing these infections back to their home country. There are many ways to mitigate this risk by seeking pre-travel advice (PTA), including receiving recommended vaccinations and chemoprophylaxis, however many travellers do not seek or adhere to PTA. We conducted a systematic review to further understand PTA-seeking behaviour with an ultimate aim to implement interventions that improve adherence to PTA and reduce morbidity and mortality in travellers.

METHODS

We conducted a systematic review of published medical literature selecting studies that examined reasons for not seeking PTA and non-adherence to PTA over the last ten years. 4484 articles were screened of which 56 studies met our search criteria after full text review.

RESULTS

The major reason for not seeking or non-adherence to PTA was perceived low risk of infection while travelling. Side effects played a significant role for lack of adherence specific to malaria prophylaxis.

CONCLUSIONS

These data may help clinicians and public health providers to better understand reasons for non-adherence to PTA and target interventions to improve travellers understanding of potential and modifiable risks. Additionally, we discuss specific recommendations to increase public health education that may enable travellers to seek PTA.

Effectiveness of twice a week prophylaxis with atovaquone-proguanil (Malarone®) in long-term travellers to West Africa

BACKGROUND

Current guidelines recommend daily dosing of atovaquone-proguanil (AP), beginning a day before travel to endemic areas and continuing for 7 days after departure. Adherence of long-term travellers to daily malaria chemoprophylaxis tends to be poor, even when residing in highly endemic malaria regions. Evidence from a volunteer challenging study suggests that non-daily, longer intervals dosing of AP provides effective protection against Plasmodium falciparum This study examines the effectiveness of twice weekly AP prophylaxis in long-term travellers to highly endemic P. falciparum areas in West Africa.

METHODS

An observational surveillance study aimed to detect prophylactic failures associated with twice weekly AP, during the years 2013-2014, among long-term expatriates in two sites in West Africa. The expatriates were divided according to the malaria prophylaxis regimen taken: AP twice weekly; mefloquine once weekly and a group refusing to take prophylaxis. Malaria events were recorded for each group. The incidence-density of malaria was calculated by dividing malaria events per number of person-months at risk.

RESULTS

Among 122 expatriates to West Africa the malaria rates were: 11.7/1000 person-months in the group with no-prophylaxis (n = 63); 2.06/1000 person-months in the 40 expatriates taking mefloquine (P = 0.006) and no cases of malaria (0/391 person-months, P = 0.01) in the twice weekly AP group (n = 33).

CONCLUSIONS

No prophylaxis failures were detected among the group of expatriates taking AP prophylaxis twice weekly compared with 11.7/1000 person-months among the no-prophylaxis group. Twice weekly AP prophylaxis may be an acceptable approach for long-term travellers who are unwilling to adhere to malaria chemoprophylaxis guidelines.

Malaria Prophylaxis: A Comprehensive Review

The flow of international travellers to and from malaria-endemic areas, especially Africa, has increased in recent years. Apart from the very high morbidity and mortality burden imposed on malaria-endemic areas, imported malaria is the main cause of fever possibly causing severe disease and death in travellers coming from tropical and subtropical areas, particularly Sub-Saharan Africa. The importance of behavioural preventive measures (bed nets, repellents, etc.), adequate chemoprophylaxis and, in selected circumstances, stand-by emergency treatment may not be overemphasized. However, no prophylactic regimen may offer complete protection. Expert advice is needed to tailor prophylactic advice according to traveller (age, baseline clinical conditions, etc.) and travel (destination, season, etc.) characteristics in order to reduce malaria risk.

Assessment of adherence to atovaquone-proguanil prophylaxis in travelers

BACKGROUND

Malaria continues to be a serious, world-wide infection. Atovaquone-proguanil is one of the prophylactic agents recommended for travelers to endemic regions. However, little information is available regarding adherence with this medication. A large proportion of malaria cases reported from travelers is due to non-adherence to prescribed regimens. This study was undertaken to analyze adherence with atovaquone-proguanil prophylaxis and specific factors contributing to non-adherence.

METHODS

Men and non-pregnant women > or = 18 years of age were eligible for inclusion. Enrolled travelers received a prescription for atovaquone-proguanil prophylaxis and were contacted by telephone within 3 weeks of return to the United States. A questionnaire was prepared by the authors to determine if subjects were adherent with the medication. Additional data included demographics, duration of malarious travel, previous use of prophylactic agents, underlying medical conditions, concurrent medications, and reasons for non-adherence.

RESULTS

Complete data were available for 104/124 (84%) participants: 49 (47%) men, 55 (53%) women. Average duration of malarious travel was 12 days, and 19 (18%) travelers reported previous travel to a malarious region. Ninety-two (89%) subjects were completely adherent with their prophylactic atovaquone-proguanil course. Adverse effects were seen in 6 (5%) travelers.

CONCLUSIONS

Adherence with atovaquone-proguanil malaria prophylaxis is high among travelers from a non-endemic region. Adverse effects are minimal. Non-adherence was primarily attributable to travelers' perception of need.