Worms, diseases that affect billions of people worldwide, have little progress in clinical studies. Among the reasons for this is the fact that they reach poorer populations and do not attract investment from pharmaceutical companies.
This warning was published in a study published in the journal Drug Discovery Today by researchers from the University of São Paulo (USP) and the University of Guarulhos, supported by the São Paulo Research Foundation (FAPESP).
This work is part of the context in which the World Health Organization (WHO) in 2021, an action plan to eradicate or control by 2030, 20 diseases that affect one in five people in the world and about 500,000 people annually. kills, executed. .
Of the 20 diseases, the five that affect the most people in absolute numbers are worms. One of the strategies adopted in the search for new drugs is drug repositioning, studying existing drugs for these neglected diseases.
Among the many goals included in the WHO roadmap is the search for new drugs, since many of these diseases do not have vaccines or drugs that are very effective.
Although it works relatively well, it is not enough to control the disease, especially because there is no 100% effective drug, says Josué de Moraes, Coordinator of the Research Core in Neglected Diseases (NPDN) at the University of Guarulhos. One of the authors of the article
Schistosomiasis
Moraes mentions the case of schistosomiasis as an example, which is considered the main worm in terms of morbidity and mortality. “Although ascariasis, which is the roundworm, affects a larger proportion of approximately one billion people, schistosomiasis has a greater health impact,” he explains.
There is only one drug for this disease, Praziquantel. “Imagine having medicine for a population of over 200 million people,” he compares. In addition, this drug does not affect the young form of the parasite and prevents the initiation of treatment early in the infection.
Among the effects of worms, the researcher highlights the fact that it impairs children’s intellectual development, contributes to lower education rates, and can also cause a person to take sick leave from work. He says: “I always say that these diseases not only prevail in conditions of poverty, but are a strong obstacle to the development of countries and thus are decisive in maintaining inequality.”
Among the reasons that prevent the development of studies in the field of parasitology, Moraes mentions four cases. As the first obstacle, he points out: Infectious diseases are the most neglected among the neglected, mainly because it is the type of disease that is more associated with the issue of poverty than any other. He also points to the fact that the disease does not create a sense of urgency. “They don’t clearly show that there is a need for population.” He recalls that in some areas, worms are even seen as something common and everyday.
Another problem occurs in laboratories. Worms are difficult to maintain. “Unlike some diseases caused by protozoa such as malaria, leishmaniasis, Chagas disease, etc., it is much more difficult to keep the worm in the laboratory.” This harms the biological knowledge of worms. “If you have one, you have to have a definitive host, usually we use a rodent and an intermediate host, in the case of schistosomiasis, a snail.” Moraes also highlights the disgust that worms cause in people.
This researcher emphasizes that other public health measures such as diagnosis, control of transmission vectors and general public health are necessary to deal with these diseases. We have about 30 million Brazilians who live without purified water. Almost half of the people do not have access to sewage. So this reinforces what I would say is an unfortunate image of the insidious.” He evaluates.