Filarial nematodes — MCQs

A 39-year-old man presents to his primary care physician with a high fever, cough, and malaise. One week ago, he returned from a vacation to Hawaii where he went waterskiing with his family. Three days before presentation, he started experiencing intermittent abdominal pain, which was followed by flu-like symptoms, itchiness in his eyes, and photosensitivity. On presentation, his temperature is 103°F (39.4°C), blood pressure is 114/72 mmHg, pulse is 105/min, and respirations are 18/min. Physical exam reveals conjunctivitis and mild jaundice. Which of the following treatments could be used to treat this patient's condition?

A 32-year-old woman presents to your office with abdominal pain and bloating over the last month. She also complains of intermittent, copious, non-bloody diarrhea over the same time. Last month, she had a cough that has since improved but has not completely resolved. She has no sick contacts and has not left the country recently. She denies any myalgias, itching, or rashes. Physical and laboratory evaluations are unremarkable. Examination of her stool reveals the causative organism. This organism is most likely transmitted to the human host through which of the following routes?

An otherwise healthy 39-year-old woman presents to her primary care provider because of right-leg swelling, which started 4 months ago following travel to Kenya. The swelling has been slowly progressive and interferes with daily tasks. She denies smoking or alcohol use. Family history is irrelevant. Vital signs include: temperature 38.1°C (100.5°F), blood pressure 115/72 mm Hg, and pulse 99/min. Physical examination reveals non-pitting edema of the entire right leg. The overlying skin is rough, thick and indurated. The left leg is normal in size and shape. Which of the following is the most likely cause of this patient condition?

A 16-year-old boy is brought to the physician by his host parents for evaluation of a progressively pruritic rash over his shoulders and buttocks for the past 6 months. He recently came to the United States from Nigeria to attend a year of high school. He reports that it has been increasingly difficult for him to read the whiteboard during classes. Physical examination shows symmetrically distributed papules 4–8 mm in diameter, excoriation marks, and patchy hyperpigmentation over his shoulders, waist, and buttocks. There is nontender inguinal lymphadenopathy and several firm, nontender subcutaneous nodules along the right iliac crest. Six skin snip biopsies are taken from the pelvic girdle, buttocks, and thigh, and are then incubated in saline. After 24 hours, microscopic examination shows motile microfilariae. Which of the following is the most likely diagnosis?

A 29-year-old internal medicine resident presents to the emergency department with complaints of fevers, diarrhea, abdominal pain, and skin rash for 2 days. He feels fatigued and has lost his appetite. On further questioning, he says that he returned from his missionary trip to Brazil last week. He is excited as he talks about his trip. Besides a worthy clinical experience, he also enjoyed local outdoor activities, like swimming and rafting. His past medical history is insignificant. The blood pressure is 120/70 mm Hg, the pulse is 100/min, and the temperature is 38.3°C (100.9°F). On examination, there is a rash on the legs. The rest of the examination is normal. Which of the following organisms is most likely responsible for this patient’s condition?

A 19-year-old woman presents to the emergency department with complaints of blurry vision and headaches that started 2 days ago. She reports that she has been experiencing some facial pain, but she thought it was related to her toothache. She is also worried about a black spot that is increasing in size on her face over the last month. She expresses concerns about her frequency of urination. Recently, she had a runny nose and cough that resolved spontaneously. The patient was diagnosed with type 1 diabetes mellitus at 13 years of age. She is a non-smoker and drinks beer occasionally. Her blood pressure is 122/98 mm Hg and temperature is 37.2°C (98.9°F). The physical examination is normal with the exception of a black necrotic eschar lateral to the right nasal ala. She lost 2.7 kg (6 lb) since her last visit, which was 6 months ago. A routine urinalysis at the office is positive for glucose and ketones. What is the most likely cause of the patient’s symptoms?

A 58-year-old man presents with a high-grade fever, throbbing left-sided headache, vision loss, and left orbital pain. He says that his symptoms started acutely 2 days ago with painful left-sided mid-facial swelling and a rash, which progressively worsened. Today, he woke up with complete vision loss in his left eye. His past medical history is significant for type 2 diabetes mellitus, diagnosed 5 years ago. He was started on an oral hypoglycemic agent which he discontinued after a year. His temperature is 38.9°C (102.0°F), blood pressure is 120/80 mm Hg, pulse is 120/min, and respiratory rate is 20/min. On examination, there is purulent discharge from the left eye and swelling of the left half of his face including the orbit. Oral examination reveals extensive necrosis of the palate with a black necrotic eschar and purulent discharge. Ophthalmic examination is significant for left-sided ptosis, proptosis, and an absence of the pupillary light reflex. Laboratory findings are significant for a blood glucose level of 388 mg/dL and a white blood cell count of 19,000 cells/mm³. Urinary ketone bodies are positive. Fungal elements are found on a KOH mount of the discharge. Which of the following statements best describes the organism responsible for this patient’s condition?

A 4-month-old boy is brought to the physician by his father because of a progressively worsening rash on his buttocks for the last week. He cries during diaper changes and is more fussy than usual. Physical examination of the boy shows erythematous papules and plaques in the bilateral inguinal creases, on the scrotum, and in the gluteal cleft. Small areas of maceration are also present. A diagnosis is made, and treatment with topical clotrimazole is initiated. Microscopic examination of skin scrapings from this patient's rash is most likely to show which of the following findings?

A 22-year-old man comes to the physician because of abdominal pain, diarrhea, and weight loss that started after a recent backpacking trip in Southeast Asia. He does not smoke or drink alcohol. His leukocyte count is 7,500/mm3 (61% segmented neutrophils, 13% eosinophils, and 26% lymphocytes). Stool microscopy shows rhabditiform larvae. This patient is most likely to develop which of the following?

A 47-year-old man presents to the emergency department with jaundice and extreme fatigue for the past 4 days. He also noticed that his stool is very pale and urine is dark. Past medical history is unremarkable. The review of systems is significant for a 23 kg (50 lb) weight loss over the last 3 months which he says is due to decreased appetite. He is afebrile and the vital signs are within normal limits. A contrast computed tomography (CT) scan of the abdomen reveals a mass in the pancreatic head. A blood test for carbohydrate antigen (CA19-9) is positive. The patient is admitted to the intensive care unit (ICU) and undergoes surgical decompression of the biliary tract. He is placed on total parenteral nutrition (TPN). On day 4 after admission, his intravenous access site is found to be erythematous and edematous. Which of the following microorganisms is most likely responsible for this patient’s intravenous (IV) site infection?