An international study led by ISGlobal analyses for the first time the cost-effectiveness of screening all adult Latin American migrants at primary health centres. The results, published in Lancet Global Health, show that the option of systematic screening (and treatment when necessary) is more cost-effective than that of only diagnosing and treating symptomatic patients.
Chagas disease prevalence in Europe has considerably increased over the last years as a result of migrants that arrive from endemic regions in Latin America. Most adults infected with T. cruzi remain asymptomatic, but 30 to 40% of them will end up developing cardiac and gastrointestinal complications that can lead to premature death. The estimated economic burden of Chagas worldwide is 7 billion USD; 15% of this cost pertain to non-endemic countries and is mainly due to cardiovascular disease and premature death. Some European countries currently recommend screening programmes for blood banks and transplant settings as well as in pregnant women (at least in some regions of Spain and Italy) to avoid vertical transmission of the parasite. These strategies have been shown to be cost-effective. However, the economic value of systematically screening, and treating, asymptomatic migrants from disease-endemic countries had not been demonstrated.
The authors of the study applied a mathematical model to compare the test option (screening of asymptomatic individuals, treatment and follow-up of positive cases) with the non-test option (diagnosis, treatment and follow-up only of symptomatic patients). For each group, they calculated the cost and the number of quality-adjusted years of life gained (QALYs). They found that, independently of the type of analysis used (deterministic or probabilistic), the test option was more cost effective. “This is true even with a decrease in disease prevalence to 0.05% (the current estimated prevalence in Europe is 4.2%),” says Ana Requena, first author of the study.
“If we consider that the treatment has a 20% efficacy, each year of life gained costs 6,840€” explains Elisa Sicuri, economist and senior author. “If the efficacy increases to 50% with the use of new therapeutic biomarkers, we would have to invest only 4,243€ per life-year gained”. These amounts are way below the currently accepted 30,000€ threshold per QALY in Spain and other European countries.
The authors conclude that these results provide, for the first time, economic arguments to implement a T. cruzi screening program in primary health centres of European countries hosting Latin American migrants. However, they also point out the need of considering other aspects such as the heterogeneity of European health systems and the acceptability of the screening programme by the potential recipients.
Requena-Méndez A, Bussion S, Aldasoro E, Jackson Y, Angheben A, Moore D, Pinazo MJ, Gascón J, Muñoz J, Sicuri E. Cost-effectiveness of Chagas disease screening in Latin American migrants at primary health-care centres in Europe: a Markov model analysis. Lancet Glob Health. 2017 Feb 27. pii: S2214-109X(17)30073-6. doi: 10.1016/S2214-109X(17)30073-6.