Is travel prophylaxis worth while? Economic appraisal of prophylactic measures against malaria, hepatitis A, and typhoid in travellers.

OBJECTIVES To estimate the costs and benefits of prophylaxis against travel acquired malaria, typhoid fever, and hepatitis A in United Kingdom residents during 1991. DESIGN Retrospective analysis of national epidemiological and economic data. MAIN OUTCOME MEASURES Incidence of travel associated infections in susceptible United Kingdom residents per visit; costs of prophylaxis provision from historical data; benefits to the health sector, community, and individuals in terms of avoided morbidity and mortality based on hospital and community costs of disease. RESULTS The high incidence of imported malaria (0.70%) and the low costs of providing chemoprophylaxis resulted in a cost-benefit ratio of 0.19 for chloroquine and proguanil and 0.57 for a regimen containing mefloquine. Hepatitis A infection occurred in 0.05% of visits and the cost of prophylaxis invariably exceeded the benefits for immunoglobulin (cost-benefit ratio 5.8) and inactivated hepatitis A vaccine (cost-benefit ratio 15.8). Similarly, low incidence of typhoid (0.02%) and its high cost gave whole cell killed, polysaccharide Vi, and oral Ty 21a typhoid vaccines cost-benefit ratios of 18.1, 18.0, and 22.0 respectively. CONCLUSIONS Fewer than one third of travellers receive vaccines but the total cost of providing typhoid and hepatitis A prophylaxis of 25.8m pounds is significantly higher than the treatment costs to the NHS (1.03m pounds) of cases avoided by prophylaxis. Neither hepatitis A prophylaxis nor typhoid prophylaxis is cost effective, but costs of treating malaria greatly exceed costs of chemoprophylaxis, which is therefore highly cost effective.