PARASITIC INFECTIONS (Why we need better Diagnostic Approaches)

1. PARASITIC INFECTIONS
(Why we need better Diagnostic Approaches)
Dr.T.V.Rao MD
When we were Medical Students in late 1960’s Learning parasitology was a priority, our teacher
made us to think beyond many limitations in Methods for the diagnosis of infectious diseases in
particular parasitology, many people were poor and living in insanitary conditions, however the
progress in Parasitology has stagnated in the last 20–30 years with affluence in the Society, in rapid
increase in economy, vector control, mass screening programs in Schools for detection of Intestinal
parasitic infections the Government of India’s mass campaigns on communicable and vector borne
diseases. However the parasitology continues to be the neglected part in Medical Microbiology, as
many young wish to spend least Time in bench work the matters are left to the ill qualified
technicians. The primary tests currently used to diagnose many parasitic diseases have changed little
since the development of the microscope in the 15th century by Antonie van Leeuwenhoek.
Furthermore, most of the current tests cannot distinguish between past, latent, acute, and
reactivated infections and are not useful for following response to therapy or for prognosis. The
methods currently in use range from rather simple, easily managed and routine techniques to the
extremely complex cutting edge technologies of modern molecular biology and high-throughput
miniaturized methods usually done as part of thesis and research work and rarely for diagnostic
work. There is a clear need for rapid, accurate and unambiguous results. Few major advances in
clinical diagnostic testing have been made since the introduction of PCR, although new technologies
are being investigated. For many years, microscopy has been the only tool available for the
detection of parasites through inspection of blood smears tissue specimens, faeces, lymph node
aspirates, bone marrow and even cerebrospinal fluid. However, sample preparation for direct
observation is time-consuming, labor intensive, and proper diagnosis depends on qualified
laboratory technicians and skilled Microbiologists and Pathologists. The emphasis shifted towards
the Virology and advancements in parasitology not appreciated, and least attention is paid and
matters are left to the semi qualified Technicians. With the onset of AIDS pandemic there is an
abrupt raise in of opportunistic parasitic infections and created much interest in parasitology,
Pressing needs include more rapid tests without sacrificing sensitivity, value-added tests, and point-of-
care tests for both high- and low-resource settings. With initiation of ELISA the matters in
parasitology have shifted towards Immune based assays the common tool being ELISA. In situations
where biologic samples or tissue specimens are unavailable, serology alone is the gold standard for
diagnosis. Other assays include the hem agglutination (HA) test, indirect or direct
immunofluorescent antibody (IFA or DFA) tests, complement fixation (CF) test, and immunoblotting
and rapid diagnostic tests (RDTs). Rapid Antigen Detection System (RDTS) However of the
Government run and newly established Medical colleges have few facilities to establish the facilities
as the matters are not cost effective, most of the qualified with Post graduates have little idea to
really make any diagnosis
However we can have better idea on matters
We learn more about alternative methods which are gaining more and more weight these days.
Besides antigen and antibody detection molecular diagnostic tests offer new possibilities with a
detection power beyond imagination.
General Principles in learning and practice of Parasitology include

2. 1 Blood examinations
2 Faecal examinations
3 Urine examinations
4 Alternative methods (Many immunological and Molecular methods)
The systematic approach to our post graduate students include
To familiarize yourself with morphological criteria to differentiate the most common protozoan and
helminthic parasites
To improve your diagnostic skills by solving basic and advanced diagnostic exercises using a virtual
microscope, however it is only tool in our hands.
To understand the basics of diagnostics by optimizing diagnostic strategies (e.g. by minimizing false
positives or false negatives) taking into account the specific diagnostic goal, the consequence of the
diagnostic result for the patient and the concepts of predictive values.
The modern generation of Microbiologists can use digital imaging technology of parasitic infections
with Web site developed and maintained by CDC's Division of Parasitic Diseases and Malaria
(DPDM). DPDx uses the Internet to strengthen diagnosis of parasitic diseases, both in the United
States and abroad. The centre will report within few hours a probable diagnosis in many issues
related to parasitic infection including the tissue sections when we have little experience on rare
isolates this interactive and rapid exchange of information, allied with already available diagnostic
reference resources, will enhance our capacity to address the global problem of parasitic diseases. A
Diagnostic Assistance function, in which laboratory and other health professionals can ask questions
and/or send digital images of specimens for expedited review and consultation with DPDx staff. This
assistance is free of charge
Today we have few teachers left In Microbiology who can train the post graduates and make a
sensible diagnosis however an effective practice of Diagnostic parasitology is Important in the Era of
Antibiotic misuse I certainly find incorporation of improving methods in diagnosis of parasitological
diseases will certainly reduce the unnecessary use of Antibiotics, which can only increase of
emergence of Drug re In spite of many Advances in Medical profession the Parasitology suffers much
lacunae in diagnosis for optimal treatment, great reason being lack of human dedication in the
matters concerned, and lack of evaluation of skills in matters of diagnostic talents in postgraduate
examinations, and above all non-availability of advancing technologies and specialty of Parasitology
hangs between the domains of Microbiology and Pathologists. However it needs more inputs and
coordination of Veterinary sciences and Zoology Professionals.
A SIMPLE DEDICATION TO MICROSCOPY HAVE MANY SOLUTIONS?
*Dr.T.V.Rao MD Professor of Microbiology Travancore Medical College, Kollam, Kerala