A evolução do diagnóstico molecular da esquistossomose mansônica

Abstract

Schistosomiasis is a neglected disease caused by trematodes of the genus Schistosoma. Worldwide, about 207 million people in 78 countries are affected by the infection, the global burden of the disease reaches 1.9 million disability-adjusted life years (DALYs). In the Americas alone, 1.8 million people are affected by Schistosoma mansoni, responsible for the hepatointestinal manifestation of the disease. In Brazil, the national prevalence rose from 10% to the current 0.99% through the implementation of public policies for disease control that aim to diagnose and treat patients. In this sense, Kato-Katz, capable of determining the patient's infection status, as well as their parasite load, played a vital role in controlling the disease. However, due to the change in the epidemiological profile of the disease, the method has been losing its sensitivity in areas of low endemicity, as it is influenced by the patient's parasite load. Therefore, new disease diagnosis strategies have been studied to meet the need for a sensitive diagnostic method, enabling proper disease control. An alternative studied is the molecular diagnosis of the disease, which is based on the use of molecular biology as a diagnostic tool. Therefore, the aim of this work was to carry out a systematic literature review looking for works published in the last 20 years that used molecular biology to diagnose human populations affected by schistosomiasis mansoni. To this end, words referring to the proposed topic were searched for in the Medline Pubmed, Science Direct and Scielo databases with a filter from 2000 to 2021. Of the selected articles, those that used a molecular diagnosis associated with a parasitological method for schistosomiasis, and were applied to a human population residing in an endemic area for the disease were selected. After selection, 20 articles were included in the review. Of the 20 studies, 12 used stool samples, 8 urine samples and 4 serum samples. Of these works, four of them evaluated more than one type of biological sample. Articles that used stool samples showed sensitivity greater than 69% and specificity greater than 29% for this type of sample, while the sensitivity found in urine studies, in general, were greater than 88% with specificities greater than 82%. Studies that used serum samples showed sensitivities from 20% to 94.10%, with specificity above 98%. In addition to sensitivity and specificity, other accuracy values were analyzed to discuss the studied methods. The study shows the potential of using molecular biology as an alternative for diagnosing schistosomiasis mansoni in several areas with different levels of endemicity.