Synopsis
The rapid evolution of new technologies has significantly reshaped parasitology. Advances in technology have enabled researchers to answer critical questions with greater accuracy, especially regarding the causes of parasitic diseases. As a result, parasitology today is a far more robust discipline, providing clear insights into complex parasitic interactions. Researchers and pathologists are now equipped to tackle every challenge the field presents, from diagnosing diseases to understanding their transmission. The integration of current and emerging technologies paves the way for a future where parasitic infections can be managed with greater efficiency and accuracy.
Increasing Instances of Parasitic Diseases Globally
Parasitic diseases can be devastating. They cause millions of morbidities and mortalities annually. In the past, many of these diseases have been linked predominantly to tropical or subtropical areas. However, recent changes in climate, lifestyle, travel patterns, and armed conflicts have contributed to the spread of these diseases into Western regions as well. It is not uncommon for individuals who have never encountered these diseases before to get infected by protozoa. Considering existing knowledge, this can be explained by recent migrations of asymptomatic carriers, especially in the case of blood bank donors and transplant donor populations.
Microscopy in Parasitology
The standard for quick diagnostics in parasitology is microscopy. It is a relatively cost-effective method compared to other approaches used today and remains the reference standard in parasitology. Highly experienced operators use light or fluorescent microscopes. Staining biological preparations with chemical or fluorescent dyes also helps. It can improve the detection and visualization of parasite life stages. Fluorescent stains are also a standard in parasitological diagnostics. Auramine-rhodamine, an acid-fast stain, binds to mycolic acids found in protozoa such as Cryptosporidium. Although not as specific for acid-fast organisms compared with the Ziehl-Neelsen stain, fluorescent stains are more affordable and commonly used as a rapid screening tool. The low cost of this method has perpetuated its sustained use, especially in economically disadvantaged regions of the world.
Advancements in Parasitology Diagnostics
Over the past 20-30 years, only a limited number of new methods have been introduced in parasitology diagnostics. Although some new technologies have been explored, there remains an urgent need for rapid, accurate, and accessible diagnostic tests. These include value-added tests and point-of-care tests for both high and low-resource settings. In recent years, modern parasitology has focused on alternative methods to improve the diagnostics of parasitic diseases. These methods involve immunoassays, molecular-based approaches, and proteomics, using mass spectrometry platforms technology.
Challenges in Parasitology Diagnostics
The detection and diagnosis of parasite infection includes the use of several laboratory methods in addition to analyzing clinical symptoms, clinical history, travel history, and geographic location of the patient. The primary tests used to diagnose parasitic diseases have changed a little since the development of the microscope by Antonie van Leeuwenhoek. Most of the current tests cannot distinguish between past, latent, acute, and reactivated infections. They are not useful for effective response to therapy.
Parasite Disease Diagnosis
Serology-based assays and molecular-based approaches play a significant role in handling parasitic diseases. Several newer serology-based assays are highly specific and sensitive. These are Falcon assay screening test ELISA (FAST-ELISA, Dot-ELISA), rapid antigen detection system (RDTS), and luciferase immunoprecipitation system (LIPS). Molecular-based approaches like loop-mediated isothermal amplification (LAMP), real-time polymerase chain reaction, and Luminex have shown high potential in parasite disease diagnosis offering enhanced specificity and sensitivity. Proteomic technology has also been introduced for the discovery of biomarkers using tissues of biological fluids from the infected host.
Serology-based Assays
In instances where biologic samples or tissue specimens are unavailable, serology-based assays are helpful. The two categories of serology-based assays include antigen-detection assays and antibody-detection assays. They include enzyme-linked immunosorbent assay (ELISA), also called enzyme immunoassay (EIA), and all its derived tests such as the Falcon assay screening test ELISA (FAST-ELISA) and the dot-ELISA.
Other Serology-based Assays
Hemagglutination (HA) tests, indirect or direct immunofluorescent antibody (IFA or DFA) tests, complement fixation (CF) tests, and immunoblotting and rapid diagnostic tests (RDTs) are a few other serology-based assays. These tests are easy to use, and their turnaround times are like microscopy, however, they are more sensitive and specific. For individuals whose blood smears do not allow for the identification of parasites, or for patients with low parasitemia who are asymptomatic, these tests are especially important. These tests can be also very helpful in the monitoring of parasite clearance following the therapy.
Molecular-based Approaches
Molecular-based approaches include nucleic acid-based approaches, real-time polymerase chain reaction (RT-PCR), loop-mediated isothermal amplification (LAMP), Luminex xMAP technology, and proteomics. Molecular-based approaches using nucleic acid provide greater accuracy and reliability compared to existing diagnostic tests. These methods enable the detection of infections even in samples with very low parasite levels, including those from asymptomatic patients.
Conclusion
Parasitology today is an accurate and precise discipline that answers all the questions related to parasitic diseases. Traditional parasitology relies on microscopy, and that method hasn’t changed significantly since the 15th century. With the development of new diagnostic tools, a wide array of possibilities has opened. Serology-based assays help when tissues or biological samples are not available. They have significant importance in cases where blood smears do not permit parasite identification and where the patients are asymptomatic. Additionally, molecular-based approaches, which utilize nucleic acid, offer improved accuracy and reliability over traditional diagnostic methods. As a result, modern parasitology is now more focused on providing precise and comprehensive answers to the causes of parasitic infections.
