02659nas a2200289   4500000000100000008004100001260001200042653001900054653002700073100001300100700001200113700001400125700001500139700001100154700001200165700001300177700001200190700001400202700001400216700002100230245014500251856009900396300001300495490000700508520184000515022001402355       2019                            d  c12/201910aChagas disease10aRapid diagnostic tests1 aLozano D1 aRojas L1 aMéndez S1 aCasellas A1 aSanz S1 aOrtiz L1 aPinazo M1 aAbril M1 aGascón J1 aTorrico F1 aAlonso-Padilla J00aUse of rapid diagnostic tests (RDTs) for conclusive diagnosis of chronic Chagas disease - field implementation in the Bolivian Chaco region.  uhttps://journals.plos.org/plosntds/article/file?id=10.1371/journal.pntd.0007877&type=printable  ae00078770 v133 a<p>Chagas disease, caused by the parasite Trypanosoma cruzi, is the neglected tropical disease with a highest burden in Latin America. Its acute stage is mostly asymptomatic and goes unnoticed. Symptoms appear at the chronic stage, which is when diagnosis is usually made. This is based on the agreement of two conventional serological tests such as Enzyme-Linked Immunosorbent Assays (ELISAs). There are commercial kits with good sensitivity and specificity but their use is impractical in many highly endemic regions with poorly equipped laboratories. Luckily, several rapid diagnostic tests (RDTs) are available for the detection of anti-T. cruzi immunoglobulins. They are easy to operate, require no cold storage, provide fast turnaround of results, and some can work with a tiny volume of whole blood as sample. With the aim to field validate their use we compared an alternative algorithm based on a combination of RDTs with the standard based on ELISAs. In both cases a third test was available in case of discordance. RDTs were implemented by mobile teams in field campaigns to detect chronic T. cruzi-infections in the Chaco region of Bolivia. ELISAs were made in the reference laboratories located in the main hospitals of Yacuiba and Villa Montes, two major cities of the region. We enrolled 685 subjects who voluntarily participated in the study and had not been treated against the disease before. The agreement between the two main RDTs was 93.1% (638/685) (kappa index = 0.86; CI 95% 0.83-0.90). In comparison to the ELISAs algorithm, the combined use of the RDTs provided a sensitivity of 97.7% and a specificity of 96.1%. These results support the use of RDTs for the diagnosis of chronic Chagas disease in the studied region, and encourage their evaluation in other regions of Bolivia and other endemic countries.</p>  a1935-2735