Background This study aims to estimate the costs-effectiveness of introducing a universal syphilis screening and treatment package with an enhanced quality assurance system among isolated indigenous populations in the Amazon region of Brazil.

Methods In three indigenous health units (Umariacu II, Vendaval and Betania), incremental financial and economic costs of the full programme were collected including start-up, training and quality assurance, supervision and implementation. These units were chosen because of their different geographic access levels (easy to very difficult) so that results can be extrapolated to other health districts of the Amazon state. Unit cost per person screened and treated was estimated as well as the cost-effectiveness per adverse outcome and DALY averted. This study also provides the first data on prevalence rates in this population.

Results Using rapid syphilis tests, the prevalence of syphilis was 1.56% and 2.2% in the sexually active population and in pregnant women respectively at the three health units. The total financial cost of syphilis screening 4173 people was $277 853. The total economic cost was $285 995.67. The economic cost per person screened was US$68.53 and treated was US$4028.11. The cost per DALY saved was US$484.31 (including stillbirth). Personnel costs contributed the largest input category consisting of 87.5% of the total costs, due to the high cost of labour of FUNASA (National Health Foundation) personnel. Training costs are also high due to the frequency of staff turnover and thus the need for repeated trainings.

Conclusions Although the cost per person screened and per person treated for syphilis could be considered high by international standards, the only alternative to screening in the health units for this population would be transporting people to the nearest larger town for screening in the nearest health facility with a laboratory. This would clearly exceed the costs of treating the cases locally by far. This therefore makes rapid syphilis testing the most cost-efficient alternative for testing these remotely located populations. Additionally, because of cultural behaviour of the indigenous populations and the fact that some of them are located near border regions of Brazil, the prevalence scenario can change quickly, increasing the number of syphilis and HIV cases in the absence of prompt identification and treatment.