Innovative test speeds up diagnosis of Chagas disease in newborns – News

Researchers from the Barcelona Institute for Global Health (ISGlobal) have succeeded in creating an innovative test, tested in Bolivia, that combines 3D technology and DNA amplification to speed up the diagnosis of Chagas disease in newborns.

According to the World Health Organization, this pathology is caused by the parasite Trypanosoma cruzi (T. cruzi), which remains hidden for years in the heart and digestive muscles of those infected, causing heart problems and, in one in ten cases, digestive disorders. . Health (WHO).

Chagas disease can become fatal over the years due to arrhythmia or progressive heart failure.

Improving detection in endemic areas

This new method, tested in the Bolivian Chaco, an endemic region for the disease, uses a DNA extraction system based on a 3D printer modified with a loop-mediated isothermal molecular amplification (LAMP) mixture that allows detection of T. cruzi infection in newborns.

The study, published in the journal Lancet Microbe, was coordinated by 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 due to vertical (or congenital) transmission, which is when an infected mother passes the parasite to her baby during pregnancy.

Early detection of the parasite in women and newborns is therefore a public health priority, but the problem is the lack of simple, rapid and reliable tests.

In high-income countries such as Spain, newborn diagnostics can be performed using PCR, but this is an expensive method that requires trained personnel.

On the other hand, in endemic regions, up to two microscopic examinations (at birth and at two months of age) should be performed, which, due to their low sensitivity, should be followed after a few months by a serological examination to detect antibodies against the parasite.

Multiple tests and the time that passes 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 a newborn, when treatment works best,” explained ISGlobal researcher Julio Alonso.

Some promising results

In this study, Alonso’s team evaluated an innovative diagnostic test that combines a simple molecular amplification method (LAMP) developed by the Japanese company Eiken with a 3D printer modified to extract DNA from a small blood sample (PrintrLab).

The project included 224 neonates of T. cruzi seropositive mothers who were followed for eight months, identifying 23 cases of congenital transmission (nine neonates by microscopy and 14 by serology eight months later).

The LAMP method was able to detect 13 of 23 cases at the outset, i.e. four additional cases to those detected by microscopy, while PCR did the same with 14 of 23 (five additional cases).

“This shows that the sensitivity of the PrintrLab-LAMP test is higher than that of microscopic analysis and almost the same as that of PCR,” Alonso said, adding that the benefit of this knowledge is that PrintrLab “should be cheaper than PCR” and requires minimal infrastructure.

In accordance with the guidelines for diagnosis and treatment of congenital Chagas disease adopted in this South American country, all infected newborns were treated and cured.

The research team explained that this was a proof of concept to show the viability of the PrintrLab-LAMP test and that “it now needs to be tested on a larger scale” because, if its potential is confirmed, it could be used to detect acute infections in adults or assess the effectiveness of treatments.