Monthly Case Studies - 2008
A nine-year-old boy from Central America, who had recently immigrated to the United States with his family, was taken to a local health facility with complaints of intestinal cramping and intermittent diarrhea. A stool specimen was obtained for ova and parasite (O&P) testing. A formalin-ethyl acetate (FEA) concentration was performed. The following figures show what was observed on a wet mount prepared from the concentrate. Figure A was taken at 100x magnification; Figures B-D at 400x magnification (Figures B and C are of the same field but in different planes of focus). The large objects of interest measured approximately 52 micrometers in length by 22 micrometers in width. What is your diagnosis? Based on what criteria?
A small, cream-colored worm-like object was discovered in the diaper of a 15-month-old child. The suspect worm was collected by the child’s parents and sent to the State Health Department for identification. A laboratorian at the State Laboratory identified the worm but requested confirmation. The specimen was sent to the Reference Laboratory at CDC for diagnostic assistance. Figures A and B show the gross morphology of the specimen. Figures C and D show smaller structures that were observed in the transport medium (10% formalin). These smaller structures were approximately 85 micrometers in length. What is your diagnosis? Based on what criteria?
A 45-year-old immigrant from Mexico was admitted to the hospital after experiencing headaches, fever, pulmonary symptoms, and adenopathy. Because of his travel history, a blood specimen was collected and sent to Hematology for routine work-up, including blood parasitology. Figures A and B show objects observed on a Giemsa-stained thick smear of the blood specimen. Figures C and D show objects observed on a Giemsa-stained thin smear of the blood specimen. All images were captured at 1000x magnification. The objects in the figures measured on average 180 micrometers in length. What is your diagnosis? Based on what criteria?
A 50-year-old man went to his health care provider after a week of intermittent diarrhea, cramps and nausea. Stool specimens were collected over three consecutive days and sent to the local public health laboratory for routine ova and parasite (O&P) work-up. Figures A-C show objects observed at 1000x magnification on a trichrome-stained slide prepared from the stool specimens. The objects measured approximately 12 micrometers in length. What is your diagnosis? Based on what criteria?
A 45-year-old man from Kenya who was visiting relatives in the New England area had complaints of fever and headache. He was taken to a nearby hospital for medical evaluation. A Giemsa-stained thin blood smear was prepared and examined at 1000x magnification. Figures A and B show what was observed in low numbers on the smear. What is your diagnosis? Based on what criteria? What, if any, other tests should be performed?
A 28-year-old man had loss of appetite, weight loss, and intermittent diarrhea approximately one week after attending a family reunion located on a farm in the mid-western U.S. He sought medical attention with his primary care provider who collected a stool specimen for ova and parasite (O&P) examination using a single-vial fixative system. A stool smear was prepared, stained with trichrome, and examined at 1000x magnification. The objects shown in Figures A-D were observed in moderate numbers. Objects in Figures C and D were 12 and 15 micrometers in diameter respectively. The object in Figure E was 4 micrometers in diameter. What is your diagnosis? Based on what criteria?
A 30-year-old who frequents sushi restaurants started experiencing severe gastritis, including epigastric pain, nausea and vomiting. He had reported eating at a sushi restaurant the previous day. After being admitted to the hospital for severe pain, a gastric biopsy was performed. A tissue specimen was sectioned and stained with hematoxylin and eosin (H&E). The attending pathologist observed unusual structures from the biopsied material and sent the slide to the CDC for diagnostic assistance. Figures A-C show structures observed on the slide; images were captured at 100x, 200x and 400x, respectively. What is your diagnosis? Based on what criteria?
A 25-year-old man returned from three months of studying abroad in southeast Asia. Countries he visited during his studies included the Philippines, Indonesia and Thailand. Shortly after returning to the United States, he presented to his health care provider with abdominal pain, cramps and diarrhea. Due to the travel history, a routine ova and parasite (O&P) examination was performed on the patient's stool. Objects A-F show objects observed in the formalin-concentrated stool specimen. All images were captured at 400x magnification. The object in Figure A measured approximately 70 micrometers long by 47 micrometers wide and was seen in large numbers. The objects in Figures B and E measured approximately 75 micrometers long by 60 micrometers wide and were seen in moderate numbers. The object in Figure C measured approximately 67 micrometers long by 38 micrometers wide and was seen in moderate numbers. The objects in Figures D and F measured approximately 25 micrometers long by 13 micrometers wide and were seen in rare numbers. What is your diagnosis? Based on what criteria?
A 29 year-old man with travel history to Costa Rica, Belize, and Nicaragua developed an ulcerative lesion on his right foot. The lesion did not respond to over-the-counter medications so the patient went to his health care provider. He was referred to an infectious disease specialist due to his travel history. A biopsy was performed near the edge of the lesion and the tissue specimen was sent to a reference laboratory for testing. The tissue specimen was divided into two parts, one of which was used to inoculate a NNN slant for culture. The other part was used to prepare a touch-prep smear, which in turn was fixed with methanol and then stained with Giemsa. Figures A and B show what was observed on that smear. What is your diagnosis? Based on what criteria?
A 37-year-old man began experiencing severe diarrhea about one week after attending a family social event. At the request of his medical provider, a fecal specimen collected in the two-vial system consisting of one vial with 10% formalin and one vial with Zn-PVA (zinc-based polyvinyl alcohol) was submitted for examination. An FEA concentration procedure and wet mount examination was done on the formalin preserved specimen. Figures A-C shows structures that were found in moderate numbers at 1000x magnification. The structures measured about 8-10 micrometers in diameter. A smear was made from the specimen preserved with PVA and stained using trichrome. Figures D and E show similar round objects that were observed. What is your diagnosis? Based on what criteria? What other testing methods would you suggest?
A study was conducted on herding dogs in a sheep-raising region of northeastern Arizona to determine the prevalence of Echinococcus granulosus. Public health officials wanted to determine the risk for hydatid cyst disease in the local people. Stool specimens from the dogs were collected and taken back to a laboratory for analysis. Figures A and B show objects recovered from the stool of several of the dogs. The objects varied in length from 10-13 centimeters and measured approximately 2 millimeters wide. What is your diagnosis? Based on what criteria?
A 25-year-old man, who recently returned from a trip to Brazil, presented to his health care provider with a festering lesion on his forehead. The patient also complained of feeling things moving under his skin. Surgical removal of the outer surface of the lesion revealed several maggot-like organisms (Figure A) beneath the skin. Specimens were sent to the CDC for diagnostic assistance. Figure B shows a close-up of the anterior end of one of the organisms; Figure C shows a close-up of the posterior end. Figures D and E show structures dissected out of the anterior end of one of the organisms. What is your diagnosis? Based on what criteria?
A 29-year-old man presented to his physician with recurring abdominal cramping, watery diarrhea, and general fatigue. A stool specimen was collected for ova and parasite testing. The laboratory used a commercially available concentration method. The objects shown in Figures A and B were observed at 1000x magnification. The objects measured 40 and 43 micrometers in length respectively. What is your diagnosis? Based on what criteria?
Wright-Giemsa stained blood smears and EDTA blood were sent for confirmatory diagnosis to the CDC from a Public Health Laboratory. The specimens were from a 46-year-old woman, but no travel history was available. Image A was captured from a stained thick smear; images B, C, and D were captured from a stained thin smear. All images were taken at 1000x magnification. What is your diagnosis? Based on what criteria? What other testing, if any, would you recommend?
Within a week of returning from a conference in Mexico, a 28-year-old woman presented to her primary care physician with cramps, abdominal pain, gas and diarrhea. A routine Ova and Parasite (O&P) examination was performed on stool specimens. Figures A-F show objects observed on a trichrome-stained slide prepared from the stool. All images were taken at 1000x oil magnification. The objects in Figures A-C measured 12 micrometers. The objects in Figures D and E averaged 10 micrometers. The object in Figure F measured 12 micrometers in diameter. What is your diagnosis? Based on what criteria?
A 19-year-old male from Louisiana with no known travel history outside the United States presented to his health care provider with a one-month history of headache, fatigue, shortness of breath and weight-loss. A chest radiograph showed significant bilateral pleural effusions with an infiltrate in the left lung. Bronchial alveolar lavage (BAL) and sputum specimens were collected for complete microbiologic and pathologic work-up. Figures A and B show Papanicolaou-stained concentrates from the BAL specimens. Figure A and B were taken at 100x and 1000x oil magnification, respectively. Objects in the figures measured approximately 85-90 micrometers long by 55-60 micrometers wide. What is your diagnosis? Based on what criteria?
A 32-year-old Latin American man sought medical attention for persistent fever and cough. A sputum specimen was collected for testing. Smears were prepared and stained with Giemsa. The images in Figures A and B show forms that were observed in very low numbers on the smears. Figures A and B were captured at 200x and 1000x oil magnification, respectively. The object measured approximately 490 micrometers in length. What is your diagnosis? Based on what criteria?
An 8-year-old child was taken to a hospital with fever, hepatomegaly, and persistent cough. The parents told the physician that the child commonly eats dirt, even though they have tried to discourage the habit. A series of tests were conducted, including a liver biopsy. A section made from the biopsy was stained with hematoxylin and eosin (H&E). The following images show what was observed in the specimen. Figures A, B, and C were taken at 200x magnification; Figure D was taken at 1000x oil magnification. The structures shown in Figure D were approximately 57 micrometers long by 32 micrometers wide. What is your diagnosis? Based on what criteria?
A 47-year-old male with travel history to the Galapagos Islands, Ecuador and Colombia presented to his health care provider with follicular conjunctivitis. A worm-like object measuring approximately 3.0 mm was removed from his eye and sent to a pathology laboratory for analysis. The object was sectioned, stained with hematoxylin and eosin (H&E) and examined microscopically. Figure A shows the object at 40x magnification; Figure B shows a close-up of one end of the object at 100x magnification. What is your diagnosis? Based on what criteria?
A seven-year-old, previously healthy child developed flu-like symptoms and rapidly progressive bulbar palsy, coma, and eventually death. Imaging revealed florid ventriculitis. A viral etiology was initially suspected. The autopsy revealed extensive necrotizing (mixed inflammatory, occasional giant cells, vasculitic) granulomatous encephalitis (Figures A and B), with a subependymal necroinflammatory process. Tissue sections of the brain were made and stained with hematoxylin and eosin (H&E). Images of the brain and subsequent tissue sections (Figures C and D, taken at 1000x oil magnification) were sent to DPDx for diagnostic assistance. What is your diagnosis? Based on what criteria? What further testing is recommended?
Images were taken from a thick blood smear stained with hematoxylin from an adult male from Cameroon. The following images, A-C were all captured from the same field of view. Figure A was captured at 400x magnification; Figures B and C were captured at 1000x oil magnification. What is your diagnosis? Based on what criteria?
A survey was conducted to determine the prevalence of geohelminth infections in school-age children living in Haiti. The laboratory aspect of the survey consisted of processing stool specimens which were collected in 10% formalin. Per protocol, the processing included performing an FEA (formalin-ethyl acetate) concentration and examination of a wet mount. The following images show what was found in one of the specimens. All images (Figures A-C) were taken at 200x magnification; Figures A and B are of the same field but at different focal planes. The lemon or barrel-shaped objects measured 50-55 micrometers in length. What is your diagnosis? Based on what criteria?
A woman found a worm in her laundry basket and contacted the health department in her state for assistance. She reported small children in the household, as well as dogs and cats. The worm was examined at the state health laboratory; it measured approximately 7.5 centimeters in length (Figure A). Eggs were removed from the worm and an iodine-stained wet mount was made. Images were sent to DPDx for diagnostic assistance. Figure B was taken at 100× magnification. Figure C was taken at 400× magnification and measured approximately 75 micrometers. What is your diagnosis? Based on what criteria? What other feature(s) would be helpful for identification?
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?
DPDx is an education resource designed for health professionals and laboratory scientists. For an overview including prevention and control visit www.cdc.gov/parasites/.
- Page last reviewed: September 2, 2016
- Page last updated: September 2, 2016
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