08.07.2020 change 09.07.2020

Polish research produces promising results with new method for detecting toxoplasmosis

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Polish experts are conducting research on a new, more sensitive and faster method for detecting toxoplasmosis, a parasitic disease that can be caught through eating uncooked meat or contaminated water.

Around 30 percent of people are infected with the parasitic protozoan that causes toxoplasmosis called Toxoplasma gondii, with infection rates reaching 90 percent in some countries. Its ultimate hosts are cats and other felids, which infect other warm-blooded animals through ingested water or food.

Humans get infected with the toxoplasmosis protozoan mainly after eating raw and undercooked meat, especially pork and mutton. The protozoan may be present in contaminated water, unwashed fruits and vegetables, and faeces of infected cats. There have also been reports of infections after blood transfusion and organ transplantation.

In healthy people, with a properly functioning immune system, the disease is usually asymptomatic. But some studies suggest that Toxoplasma gondii can penetrate the brain and affect the behaviour of an infected person, for example increase aggression and auto-aggression, cause uncontrolled outbursts of anger and risky behaviours such as reckless driving and suicide attempts

The toxoplasmosis protozoan can be detected by blood (serological) tests or directly by testing collected biological material. The problem with the former is the so-called serological window, the period when antibodies cannot be detected (for example, in the case of toxoplasmosis, IgM antibodies appear about 1 week after infection). Using the direct method is not always possible. Meanwhile, detecting toxoplasmosis in the early stages of development increases the chances of successful treatment.

Experts from AmerLab, a spin-off company of the University of Warsaw, are conducting research on a new method for detecting toxoplasmosis. Compared to standard serological tests currently used, the new method should not only offer greater sensitivity, but also enable faster detection of infection, which opens the possibility for more effective and less burdensome treatment of patients. This is particularly important for pregnant women and people with reduced immunity, for whom toxoplasmosis is particularly threatening.

The new method involves the use of circulating free DNA (cfDNA) and modern research technology called digital droplet PCR (ddPCR) which helps to identify short DNA fragments of pathogens in selected body fluids, for example blood, plasma or urine, regardless of the location of the parasite itself. The presence of circulating free DNA is evidence of the presence of a live pathogen that can cause disease.

Dr. Renata Welc-Falęciak, assistant professor at the Department of Parasitology at the Faculty of Biology of the University of Warsaw and co-founder of AmerLab said: “We are currently in the first, preliminary stage of works to enable research into the possibility of using the new method in the diagnosis of human infections. Tests will include a group of patients with acquired immunodeficiencies and pregnant women with suspected toxoplasmosis. Research is carried out in cooperation with the Medical University of Warsaw and the Medical University of Bialystok. Preliminary results are very promising.”

Dr. Agnieszka Pawełczyk, assistant professor at the Department of Immunopathology of Infectious and Parasitic Diseases of the Medical University of Warsaw, co-founder and member of the board of AmerLab, argues that the advantage of cfDNA detection-based diagnostics is the possibility of testing a variety of relatively easily available biological material, often collected without the need for invasive methods like biopsy or puncture.

She said: “This is important in the case of those species of pathogens, the direct identification of which in the human body is complicated due to their location or life cycle complexity.”

The cost of the new test, at least initially, will be higher than the serological tests due to the use of advanced ddPCR technology. Therefore, the new method will not completely replace current diagnostic tests, but it offers greater possibilities for detecting the infection, and thus faster and more effective treatment.

Toxoplasmosis is especially dangerous for people with reduced immunity and developing foetuses. It can cause microcephaly, hydrocephalus and cerebral palsy. The risk of placental infection increases with the duration of pregnancy, and the later a pregnant woman becomes ill, the shorter the time required for infection. However, the effects on the foetus are most serious when infection occurs in the first months of pregnancy. The diagnosis of toxoplasmosis in pregnant women is complex and includes the analysis of the presence and level of IgA, IgM and IgG antibodies.

The initial research into using the new toxoplasmosis detection method is financed with funds from the Innovation Incubator 2.0 programme of the Ministry of Science and Higher Education, implemented by the University Technology Transfer Centre of the University of Warsaw.

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