Volume 10, Number 06

EVEN IN CANADA? A Case History A 20 year-old female vacationing in cottage country in Ontario began suffering from slight diarrhea. She then developed nausea, a feeling of bloating and fullness in the upper abdomen, recurring headaches, and gross fatigue. Food did not relieve or worsen the symptoms. There was no fever. An upper GI series was reported as normal. The patient was considered to be depressed and was treated with a tricyclic and diazepam. She was seen by a consultant 3 months later. Physical examination revealed a somewhat depressed single young woman with slight epigastric tenderness as the only sign. The differential diagnosis under consideration included the following: Peptic acid-medicated (ulcer) disease Bowel parasites Gall bladder disease Subacute pancreatitis Pregnancy Urinary tract infection The initial diagnostic tests ordered were as follows: Urinalysis, C&S, and pregnancy test Stool for O&P X3 Abdominal ultrasound CBC, Liver function tests, and amylase Immediate therapy included: Rigid dietary management Acid inhibitor medication (e.g. ranitidine) Discontinuance of the tranquilizers This fairly common history is true. Canadian physicians are sometimes conditioned to think of stress-associated diseases. The patient's problem, however, was proven to be giardiasis, a parasitic infection of the duodenum or upper jejunum by Giardia lamblia. The parasite was most likely acquired from the lake at her cottage. Examination of the stool provided the diagnosis. Three specimens were taken because each carries about a 70% probability of success. Thus, 2 stool specimens are 81% accurate and 3 about 94%. Metronidazole was given and she fully recovered in 10 days. (Note: Metronidazole has not been shown to be safe for use during pregnancy). G. lamblia is distributed world-wide and has a prevalence of between 1 to 9% in different populations. Not everyone who is infected is symptomatic, however many who are miserable from Giardiasis are never diagnosed. G. lamblia is easily spread through the fecal-oral route and this helps one to understand the high prevalence rate and epidemics in day care centres, institutions and in persons with unusual sexual practices. Another common route of infection is drinking water. The cystic forms survive well in mountain streams and cold lakes. To make matters worse, the cysts can survive the usual chlorination provided by municipalities. Many water purifiers carried by campers whether chemical or filtration are not effective. Boiling for about three minutes is effective. Campers, hikers, canoeists, skiers, and nature lovers should take note. A final note to be made is that the examination of the stool is an inexpensive, non-invasive and important part of the work-up of any patient with gastrointestinal dysfunction. Giardia and other intestinal parasites are universal from the Arctic to the Equator - even in Canada!

GENITAL HERPES Diagnosis Herpes simplex genitalis remains a diagnostic problem. Infection with Type II (genitalis) occurs about 9 times more frequently in the genial area than Type I (oralis). The opposite ratio applies to oral lesions. Lesions on the fingers, thighs, and other sites tend to be caused by Type II. The only laboratory way to diagnose these infections is by viral culture of the acute lesion on the skin on mucous membrane. It is not possible to diagnose Genital Herpes from a blood specimen since serological testing of the blood cannot differentiate Type I from Type II. But is valuable when it is negative since one may then conclude that the patient has neither infection. New serological tests which are claimed to differentiate antibodies of Type I from Type II are not yet perfected and may lead to an erroneous diagnosis. CML/Cybermedix will continue to monitor these tests and advise physicians if and when they become reliable.

DIAGNOSIS OF BLEEDING DISORDERS Use of Five Basic Screening Tests The physician is often confronted with the need to evaluate a bleeding disorder or a bleeding tendency. Sometimes it is simply a question of the significance of reported easy bruisibility, a common complaint. On other occasions, one must consider the possibility of a serious inherited disorder; or the crisis situation that is associated with such conditions as Disseminated Intravascular Coagulation. At the other end of the spectrum are routine screening tests performed preoperatively. Presented below is a table showing the use of five commonly available, inexpensive tests that will help the physician to verify a bleeding disorder and throw some light on its cause. Completeness is not intended. Laboratory Test Usual Diagnosis Bleeding Time Platelet Count Activated partial thrombo- plastin time Prothrombin Time Thrombin Time inc dec N N N Immunothrombocytopenia, Primary marrow disorders inc N N N N Platelet function defect, von Willebrand's disease Aspirin and some other medications inc N inc N N von Willebrand's disease N N inc N N Hemophiliac states N N inc inc N Abnormal Vitamin K-dependent coagulation factors, Liver disease inc dec inc inc inc Late disseminated intravascular coagulation (DIC), end-stage liver disease, heparin administration N N N N N Borderline coagulation factor decrease, vascular bleeding, platelet function defect, factor XIII deficiency Note: N = Normal, inc = increased or prolonged, dec=decreased Adapted from Palmer, RL. Postgrad.Med. 76:137-148 (1989) The five tests listed above require special care. The bleeding time is a measure of the time required for blood to clot after a 1 mm. deep incision is made on the anterior surface of the mid-forearm with a blood-pressure cuff placed around the upper arm and inflated to 40 mm Hg. The technique is best done by someone practiced in the procedure. The other tests are performed on venous blood. The platelet count is done with blood from a "lavender top" tube and must be well mixed right after venesection to avoid clotting. The other three tests are done with "blue top" tubes that are filled to capacity. If another blood is to be drawn, these three should be collected last to avoid tissue thromboplastins. The specimen must be rejected if there is any sign of hemolysis or clotting. The tests must be performed within 2 hours of collection.

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