PARASITIC INFECTIONS

PARASITIC INFECTIONS

Assoc.Prof.Dr.Yesim Gürol

• Five hunters spent a weekend in a cabin in the Northeastern United States. One of the hunters, who slept in a sleeping bag on the floor of the cabin, awoke in the morning with a rash on various parts of his body (Figure A). Because the area was endemic for Lyme disease, public health officials wanted to search for the tick vector. Arthropods (Figures B and C) found under a rug in the cabin were collected and sent to the state public health laboratory for identification. What is your diagnosis? Based on what criteria?

bed bug infestation caused by Cimex lectularius

• A female patient who received kidney and pancreas transplants from a cadaveric donor returned to the hospital with febrile illness six and a half weeks after the surgery. Recent travel outside of the US was not reported. A peripheral blood smear was prepared, stained with Giemsa, and examined. The organism in Figure A was observed on the smear. What is your diagnosis? Based on what criteria?

CAUSED BY AN INFECTION WITH TRYPANOSOMA CRUZI

This was a case of Chagas Disease and was acquired due to organ transplantation

• An outbreak of diarrhea affecting persons from one year of age to 70 years of age occurred in the Northeast region of Kansas. Fecal specimens were collected in 10% formalin and concentrated using the FEA concentration method. Direct fluorescent antibody assays (Merifluor DFA kits) were performed on the samples by the county and state health departments. To date, test results confirmed that over a hundred specimens had the objects shown in Figure A. What is your diagnosis? Based on what criteria? Figure B shows what was found in 5 specimens tested. What is your diagnosis? Based on what criteria?

Figure A oocysts of Cryptosporidium Figure B cysts of Giardia intestinalis. spp

• A middle-aged man from East Africa, who had immigrated to the United States 20 years ago, had an intermittent fever for two weeks, which progressed to a daily fever with chills. He had also experienced severe weight loss during the previous six months. He had traveled to Southeast Asia while living outside the U.S., and his past medical history revealed he had contracted malaria twice. It was also discovered that he was positive for HIV by antibody testing. A CT scan revealed that he had an enlarged spleen and liver. A bone marrow aspirate was obtained and part of it was stained with hematoxylin and eosin (H & E) and the rest used to inoculate a culture. Figures A and B show what was seen in the stained aspirate. Figures C and D show what was seen on a Giemsa stained smear from the culture 10 days postinoculation. What is your diagnosis? Based on what criteria?

THIS PARTICULAR CASE WAS AN EXAMPLE OF REACTIVATED VISCERAL LEISHMANIASIS (KALA-AZAR) PRECIPITATED BY A CD4 COUNT DECLINE SECONDARY TO THE PATIENT ACQUIRING HIV. THE SPECIES WAS DETERMINED TO BE L. DONOVANI

Leishmaniasis caused by Leishmania sp.

• A 41-year-old man traveled to Tanzania and Kenya. Within two weeks of his return, he went to his health care provider with complaints of intermittent fevers, malaise, and headaches. His travel history also indicated he had visited several South American countries before his trip to Africa. The doctor ordered a blood smear and instructed the man to wait for the results. The smear was stained with Giemsa and examined. Figures A-D show what was observed on the smear. What is your diagnosis? Based on what criteria?

African trypanosomiasis (African Sleeping Sickness) caused by Trypanosoma brucei rhodesiense.

• A 3 year old boy was first seen in the clinic because of failure to thrive and vague symptoms such as poor appetite and failure to gain weight. There was another child in family, a 6 year old brother who was in good health. The patient was apparently fine for the first couple of years. He began to have diarrhea with light coloured stools; however this condition was not always present. Although stool examinations were performed, it was unclear exactly what diagnostic methods were used and the test results were reported negative. The child was placed on a high protein high calorie diet with vitamins and supplements. He showed very little improvement and was admitted to the hospital with a diagnosis of celiac disease.

• What parasites should be considered based on the patients history?

• What factors might be responsible for the negative laboratory reports?

• What other diagnostic tests might be available?

• A 34 year old man from Mexico went to clinic because he found some white, rectangular objects in his stool. These objects were about an inch long and appeared to be moving very slowly. He had always been healthy and had come to the United States 2 years earlier. He denied gastrointestinal or other symptoms. He had no unusual dietary habits or significant contact with animals. During the last few days, he complained about anorexia,some nausea and abdominal cramps; he had no diarrhea. Laboratory findings were normal; the routine stool examination was as follows:

• The patient was a 52 year old man from California who had just returned from a trip to Africa. About a week after he returned, he began complaining of fever, headache and general malaise. The first blood specimens examined using automated instrumentation revealed nothing. He continued to have high fevers and severe headaches, and eventually such as thick and thin blood films were sent to the laboratory

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A 41-year-old woman from the Amazon region of Brazil presented at a local hospital with fever, chills, and myalgia.  The health care provider ordered thick and thin blood smears to be made for routine parasitological examination. The blood smears were stained with Giemsa and examined using 1000x oil immersion. What is your diagnosis?  Based on what criteria?