Test for diagnosing Chagas disease in infants

This is the conclusion reached by the results of a validation study conducted in the Bolivian Chaco, an endemic region for Chagas disease. The study was coordinated by the Barcelona Institute for Global Health (ISGlobal), a center supported by the “la Caixa” Foundation, in collaboration with the CEADES Foundation (Bolivia), CONICET-INGEBI (Argentina), AI Biosciences (USA), FIND (Switzerland) and the Mundo Sano Foundation (Argentina).

20% of new cases of Chagas disease are conditioned vertical transmission (or congenital). This occurs when an infected mother passes the parasite to her baby during pregnancy. Therefore, early detection of the parasite in women and newborns is a public health priority..

The problem is, lack of simple, fast and reliable testsIn high-income countries such as Spain, newborn diagnostics can be done using PCR, but this is an expensive method that requires trained personnel.

In endemic areas, up to two microscopic tests (at birth and at two months) are performed, which have low sensitivity and must be followed up a few months later with a serological test to detect antibodies against the parasite. The number of tests and the time interval between them increase the risk that children will not receive the treatment they need.

“In endemic areas, it would be very useful to have a simple, rapid and sensitive test to detect the parasite in newborns, when treatment is most effective,” he explains. Julio Alonso Padilla ISGlobal researcher.

More sensitive than a microscope.

In this study, Alonso-Padilla’s team evaluated an innovative diagnostic test that combines a simple molecular amplification method (LAMP) developed by the Japanese company Eiken 3D printer modified to extract DNA from a small blood sample (PrintrLab). The results were compared with the results of PCR and “standard” diagnostic methods (microscopy and serology).

The study included 224 children were born to HIV-positive mothers T. Cruzi and followed for eight months. A total of 23 cases of congenital transmission were detected (nine by microscopy at birth and an additional 14 by serology at eight months). LAMP was able to detect 13 of the 23 cases early (i.e., four additional cases compared with those detected by microscopy), and PCR was able to detect 14 of the 23 (five additional cases).

Almost the same as PCR

“This shows that The sensitivity of PrintrLab-LAMP is higher than that of microscopy and is almost equal to the sensitivity of PCR. “Alonso-Padilla says, The advantage is that PrintrLab should be cheaper than PCR And requires minimal infrastructure .

Following the country’s guidelines for diagnosis and treatment of congenital Chagas disease, all infected newborns were treated and cured, highlighting the importance of early detection and treatment .

The research team stresses that this proof of concept to demonstrate the viability of the PrintrLab-LAMP test and that it now needs to be tested on larger scale and in more centers. If its potential is confirmed, the test could also be useful for identifying acute infections in adults or assessing the effectiveness of treatment.

Reference article:

Rojas L., Rivera S., Wehrendt D.P., et al. Evaluation and validation of a PrintrLab-based LAMP assay for detection of Trypanosoma cruzi in neonates in Bolivia: a proof-of-concept study. Lancet Microbe doi: 10.1016/S2666-5347(24)00110-1.

Fountain: ISGlobal