Lec 1 Diagnosic Parasitology PDF

Dr. Qaraman M.K. Koyee Salahaddin University – Erbil Diagnostic College of Science – Biology Department Professor in Parasitology 4th Class –General Biology Parasitology...

Dr. Qaraman M.K. Koyee Salahaddin University – Erbil Diagnostic College of Science – Biology Department Professor in Parasitology 4th Class –General Biology Parasitology PhD in Molecular Parasitology Diagnostic parasitology is a branch of clinical microbiology that focuses on the identification and detection of parasitic organisms in human and animal hosts. Parasitology is the study of parasites, which are organisms that live in or on another organism, known as the host, and derive their nutrition from the host while potentially causing harm or disease. Diagnostic parasitology plays a crucial role in the field of medicine and veterinary medicine by helping to diagnose and manage parasitic infections. Key aspects of diagnostic parasitology: o Parasitic Organisms: Parasites come in various forms, including protozoa (single- celled organisms), helminths (worm-like organisms), and ectoparasites (parasites that live on the surface of the host). Some common examples include Plasmodium (the cause of malaria), Giardia, hookworms, and ticks. o Sample Collection: The first step in diagnostic parasitology is collecting appropriate clinical specimens. This may involve collecting blood, stool, urine, tissue biopsies, or skin scrapings, depending on the suspected parasite and infection site. o Microscopic Examination: Microscopy is a fundamental tool in parasitology. Technicians or microbiologists examine stained or unstained samples under a microscope to identify parasitic organisms. Special stains and techniques may be used to enhance visibility. o Serological Tests: In some cases, serological tests such as enzyme-linked immunosorbent assays (ELISA) or immunofluorescence assays (IFA) may be employed to detect antibodies or antigens associated with specific parasites in the patient's blood. o Molecular Diagnostics: Polymerase chain reaction (PCR) and DNA sequencing techniques are increasingly used to detect and identify parasites. These methods offer high sensitivity and specificity and can identify parasites even in low concentrations. o Culture and Inoculation: For certain parasites that are challenging to detect using microscopy alone, such as the amoeba Entamoeba histolytica, culturing the parasite in a laboratory setting may be necessary. o Clinical Symptoms and History: Information about the patient's symptoms, travel history, and exposure to potential sources of infection is essential for diagnosis. Some parasitic infections are more common in specific geographic regions. o Treatment and Management: Once a parasitic infection is identified, appropriate treatment options can be prescribed. The choice of treatment depends on the specific 1  Dr. Qaraman M.K. Koyee Salahaddin University – Erbil Diagnostic College of Science – Biology Department Professor in Parasitology 4th Class –General Biology Parasitology PhD in Molecular Parasitology parasite and its susceptibility to drugs. In some cases, surgery may be necessary to remove parasitic cysts or lesions. o Prevention and Control: Understanding the lifecycle of parasites, their modes of transmission, and their reservoir hosts is crucial for preventing parasitic infections. Public health measures, such as sanitation and vector control, play a vital role in preventing the spread of parasites. o Education and Research: Ongoing research in diagnostic parasitology helps improve our understanding of parasites, their evolution, and the development of new diagnostic tools and treatment strategies. Q. Why Perform Diagnostic Parasitology Testing? Diagnostic parasitology testing is performed for several important reasons: 1. Diagnosis of Infections: The primary goal of diagnostic parasitology is to identify and confirm the presence of parasitic infections in humans and animals. Knowing the specific parasite causing the infection is essential for appropriate treatment and management. 2. Clinical Decision-Making: Accurate diagnosis through parasitology testing guides healthcare providers in making informed decisions about patient care. It helps determine the most suitable treatment options and whether antimicrobial therapy is necessary. 3. Public Health Surveillance (Monitering): Diagnostic parasitology plays a critical role in public health by identifying and tracking the prevalence of parasitic diseases in communities. This information can be used to implement targeted prevention and control measures. 4. Epidemiological Investigations: Understanding the distribution and transmission of parasites is crucial for investigating outbreaks and understanding the epidemiology of parasitic diseases. This information can lead to improved control strategies. 5. Screening and Surveillance: Parasitology testing is often used for screening individuals at risk of infection, such as travelers to endemic areas, immigrants, and refugees. It helps identify asymptomatic carriers who may be a source of transmission. 6. Zoonotic Infections: In veterinary medicine, diagnostic parasitology is essential for identifying parasitic infections in animals, which can be zoonotic, meaning they can be transmitted from animals to humans. This helps prevent human infections and protect animal health. 7. Research and Surveillance: Parasitology testing is a fundamental tool in research, allowing scientists to study the biology, genetics, and evolution of parasites. It also aids in developing new diagnostic techniques and treatment strategies. 2  Dr. Qaraman M.K. Koyee Salahaddin University – Erbil Diagnostic College of Science – Biology Department Professor in Parasitology 4th Class –General Biology Parasitology PhD in Molecular Parasitology 8. Monitoring Treatment Efficacy: After initiating treatment for a parasitic infection, follow-up parasitology testing can confirm the success of treatment by detecting the absence or reduction of parasites in clinical specimens. 9. Disease Control: Diagnostic parasitology is integral to controlling parasitic diseases, whether through targeted treatment of infected individuals, mass drug administration programs, or the implementation of public health interventions such as clean water and sanitation measures. 10.Prevent Complications: Some parasitic infections, if left untreated, can lead to severe complications or chronic health issues. Early diagnosis and treatment can prevent these complications and improve patient outcomes. 11.Travel Medicine: Travelers to regions with a high prevalence of parasitic diseases may undergo diagnostic parasitology testing before and after their travels to ensure they are not infected and to detect any acquired infections early. 12.Blood and Organ Donation Safety: Parasitology testing is a routine part of blood and organ donation screening to prevent the transmission of parasitic infections through transfusions or organ transplants. Q. Who Should Perform Diagnostic Parasitology Testing? Diagnostic parasitology testing should be performed by trained and qualified individuals in clinical laboratories or healthcare settings. The following professionals are typically involved in conducting diagnostic parasitology tests: 1. Clinical Laboratory Technologists and Technicians: These are trained healthcare professionals who work in clinical laboratories. They are responsible for processing patient samples, performing diagnostic tests, and reporting results. In the context of parasitology, they may prepare and examine blood smears, stool samples, urine samples, and other clinical specimens for the presence of parasites. 2. Medical Microbiologists: Medical microbiologists are medical doctors or scientists who specialize in the diagnosis and management of infectious diseases, including parasitic infections. They provide expertise in interpreting parasitology test results, particularly in cases where diagnosis may be complex or require specialized techniques. 3. Laboratory Directors and Supervisors: Clinical laboratories are typically overseen by laboratory directors or supervisors who ensure the proper functioning of the laboratory, adherence to quality control measures, and compliance with regulatory guidelines. 4. Pathologists: Pathologists are medical doctors who specialize in the study of diseases. They may be involved in reviewing and interpreting diagnostic 3  Dr. Qaraman M.K. Koyee Salahaddin University – Erbil Diagnostic College of Science – Biology Department Professor in Parasitology 4th Class –General Biology Parasitology PhD in Molecular Parasitology parasitology results, especially in cases where histopathological examination of tissue samples is required. 5. Infectious Disease Specialists: Infectious disease physicians are medical doctors who specialize in diagnosing and treating infectious diseases. They may request and interpret parasitology tests as part of their patient evaluations. 6. Veterinarians: In veterinary medicine, parasitology testing is crucial for diagnosing parasitic infections in animals. Veterinarians often collect and interpret diagnostic samples from animals and may work closely with veterinary parasitologists for specialized testing and consultation. 7. Public Health Agencies: Public health departments and agencies may conduct or parasitology testing for surveillance (monitoring), outbreak investigations, and public health initiatives. They often collaborate with clinical laboratories to monitor and control parasitic diseases at the population level. 8. Researchers and Academics: Researchers in the field of parasitology may perform diagnostic tests as part of their studies to advance knowledge about parasites, their biology, and their interactions with hosts. Q. What Testing Should Be Performed? 1. Routine Tests: Routine diagnostic parasitology procedures could include the ova and parasite examination (O&P exam), preparation and examination of blood films and pinworm tapes, occult-blood tests, and examination of specimens from other body sites (urine, sputum, duodenal aspirates, urogenital specimens, etc.). As an example, the O&P exam (which involves direct wet mount, concentration, and permanent staining of the smear) could be considered a routine test method for the detection of several different intestinal protozoa and helminth infections. 2. Special Testing and Reference Laboratories (CDC): Special procedures, such as parasite culture, are usually performed in a limited number of reference laboratories. These procedures require the maintenance of positive control cultures used for quality control checks on all patient specimens; they also require special expertise and time. 3. Other (Nonmicrobiological) Testing: Test results from other procedures performed in a clinical laboratory can be beneficial when one is trying to diagnose a parasitic infection. Specific examples are routine urinalysis, hematology procedures including a complete blood count (CBC), and various chemistry profiles. These results often provide supporting data consistent with a suspected parasitic infection. 4  Dr. Qaraman M.K. Koyee Salahaddin University – Erbil Diagnostic College of Science – Biology Department Professor in Parasitology 4th Class –General Biology Parasitology PhD in Molecular Parasitology Specimens used in Parasitological investigations Depending on the nature of the parasitic infections, the following specimens are selected for laboratory diagnosis: A. Blood: in those parasitic infections where the parasite itself in any stage of its development circulates in the blood stream, examination of blood film forms one of the main procedures for specific diagnosis. For example, in malaria the parasites are found inside the red blood cells. In Bancroftian and Malayan filariasis, microfilariae are found in the blood plasma. B. Stool: examination of the stool forms an important part in the diagnosis of intestinal parasitic infections and also for those helminthic parasites that localize in the biliary tract and discharge their eggs into the intestine. In protozoan infections, either trophozoites or cystic forms may be detected; the former during the active phase and the latter during the chronic phase. e.g. Amoebiasis, Giardiasis, etc. In the case of helmithic infections, the adult worms, their eggs, or larvae are found in the stool. C. Urine: when the parasite localizes in the urinary tract, examination of the urine will be of help in establishing the parasitological diagnosis. e.g. in urinary Schistosomiasis, eggs of Schistosoma haematobium are found in the urine. In cases of chyluria (when fluid from the lymphatic system leaks into the kidneys and thus the urine a milky color) caused by Wuchereria bancrofti, microfilariae are found in the urine. D. Sputum: examination of the sputum is useful in the following: In cases where the habitat of the parasite is in the respiratory tract, as in Paragonimiasis, the eggs of Paragonimus westermani are found. In amoebic abscess of lung or in the case of amoebic liver abscess bursting into the lungs, the trophozoites of E. histolytica are detected in the sputum. E. Biopsy material: varies with different parasitic infections. e.g. spleen punctures in cases of kala-azar (Visceral Leishmaniasis), muscle biopsy in cases of Cysticercosis, Trichinelliasis, and Chagas‟ disease, Skin snip for Onchocerciasis. F. Urethral or vaginal discharge – for Trichomonas vaginalis. 5  Dr. Qaraman M.K. Koyee Salahaddin University – Erbil Diagnostic College of Science – Biology Department Professor in Parasitology 4th Class –General Biology Parasitology PhD in Molecular Parasitology Diseases of the digestive system: There are several diseases and conditions affecting the gastrointestinal system, including: 1. Infection: Gastroenteritis is an inflammation of the intestines. It occurs more frequently than any other disease of the intestines. Infections in the digestive system are classified in two groups: Exogenous infections –pathogens that come into the body. They are brought in with contaminated food or water. Endogenous infections are caused by organisms that are part of the normal microbial flora. 2. Cancer: may occur at any point in the gastrointestinal tract, and includes mouth cancer, tongue cancer, esophageal cancer, stomach cancer, and colorectal cancer. 3. Inflammatory conditions: Ileitis is an inflammation of the ileum; Colitis is an inflammation of the intestine, Appendicitis: Is an inflammation of the vermiform appendix located at the caecum. 4. Diverticular disease: Diverticulosis occurs when pouches form on the intestinal wall. Once the pouches become inflamed it is known as diverticulitis, (the patient's stool is red and bloody). 5. Cholelithiasis, gallstones in the gallbladder. 6. Peptic ulcer, open sore in the lining of the stomach or duodenum 7. Anal fistula, abnormal tube-like passageway near the anus. 8. Dysentery, painful, inflamed intestines commonly caused by bacterial infection. 9. Hemorrhoids, swollen, twisted, varicose veins in the rectal region. 6  Dr. Qaraman M.K. Koyee Salahaddin University – Erbil Diagnostic College of Science – Biology Department Professor in Parasitology 4th Class –General Biology Parasitology PhD in Molecular Parasitology Symptoms: Several symptoms are used to indicate problems with the gastrointestinal tract: Nausea Vomiting,which may include regurgitation of food (due to GIT inflammation, acute pain, drugs, pregnancy, emotions) or the vomiting of blood (as in upper GIT bleeding (Haematomesis). Melena, black, tarry stools; feces containing digested blood (which is a sign of upper GIT bleeding). Diarrhoea, the passage of liquid or more frequent stools (watery), more than three times in a day and more than 200g/day, and with incontinence. There are two types of diarrhea: Acute and chronic diarrhea. 1. Acute Diarrhoea : short in time , do not need any medication unless the patient is immunecomprised. Most cases (90%) are due to ingestion of contaminated food with bacteria or its toxin, viruses and parasites, the rest (10%) are due to medication drugs like antibiotics. 2. Chronic Diarrhoea: long in time (more than one month), need medication for dehydration because of losing K+, Mg++, Na+ salts which may cause death. The causes of chronic diarrhoea are colitis, malabsorption, colon cancer, irritation of small intestine with some drugs. Constipation, which refers to the passage of fewer and hardened stools (difficulty in passing stools (feces), due to: pregnancy, GIT obstructions with tumors, diverticulum and hemorrhoids (here is a weakness in the side of the anal canal that leads to thickening of the lining and then veins can enlarge to become a haemorrhoid), Age. Dysphagia, difficulty in swallowing Eructation, gas expelled from the stomach through the mouth. Flatus, gas expelled through the anus. Jaundice (icterus), yellow-orange coloration of the skin and whites of the eyes caused by high levels of bilirubin in the blood (hyperbilirubinemia). Statorrhea, fat in the feces; frothy, foul-smelling fecal matter, due to malabsorption which result from pancreatic diseases. 7