Immuno
A bacterial pathogen is introduced into the bloodstream through an infected central line. An immune cell recognizes the bacteria, digests it within a phagolysosome, and combines its peptides with a type 2 major histocompatibility complex (MHC).
Macrophages/Dendritic cells
A 50-year-old industrial worker engaged in handling animal products develops a painless papule on his right forearm where he had a minor abrasion 5 days earlier. The papule became a vesicle after 48 hours and ruptured, leaving an ulcer with a black necrotic area in the center and surrounding edema. What bacteria? Name its toxins
Bacillus Anthracis. Protective antigen, lethal toxin, edema toxin
A 20-year-old male college student presents with fever, chills, malaise, headache, photophobia, confusion, and numerous petechiae on his extremities and trunk. Patient reports having a stiff neck. Gram staining of the CSF reveals Gram-negative cocci in pairs. Name bacteria, toxin, complication.
Neisseria Meningiditis. Lipooligosacchride. Shock, DIC, Waterhouse-Friderichsen syndrome
Within 48 hours of consumption of raw oysters from a restaurant in North Carolina, 3 men in their 30s developed diarrhea and severe vomiting accompanied by headache, low-grade fever, and chills. They recovered with administration of intravenous fluid. In a week's time, all other adults and children in their households became sick with similar symptoms. A viral agent was considered as the cause of this outbreak of gastroenteritis.
Vibrio Vulnificus
A 3-year-old boy is evaluated for a 24-hour history of diarrhea. His mother reports that he had five episodes of foul-smelling watery diarrhea associated with decreased appetite. A few other children at the same daycare center have presented with the same problem. On physical examination, the child is well hydrated and his abdomen is tender. What is on your differential
Giardia
A 60-year-old man presents with a deep puncture wound on his foot. His clinical history indicates that he has recently emigrated from Peru and does not recall receiving any immunizations in childhood. Horse antibodies against tetanus are administered to him; a few days later, he develops chills, rash, and arthritis, which are caused by a small immune complex deposition in tissues. What type of hypersensitivity reaction is this?
Type III
A 42-year-old previously healthy woman comes to the office due to weakness and difficulty walking. She states she had cramping abdominal pain and diarrhea 2 weeks ago after an outdoor picnic, which spontaneously resolved after 3 days. She has had no fever, headache, neck pain, or bowel or bladder dysfunction. Vital signs are within normal limits. Bilateral lower-extremity weakness with loss of deep tendon reflexes is present. Bilateral upper-extremity muscle strength, reflexes, and coordination are normal. Sensation to touch and pinprick is normal throughout. The remainder of the examination shows no abnormalities. Which of the following is the most likely cause of this patient's current condition?
Guillain Barre. Campylobacter
A 45-year-old woman is brought to the ED via ambulance; she is accompanied by her very anxious husband. He reports that she has been vomiting for several hours, and she has complained of acute abdominal pain and blurred vision after eating home-canned green beans. Examination reveals dilated pupils, diplopia, acute paralysis of the upper limbs, and respiratory distress. What bacteria?
Clostridium Botulinum
A 56-year-old man was admitted to a hospital in central Illinois with symptoms of high fever, chills, dry cough, headache, night sweats, and chest pain of 7 days duration. He has been experiencing shortness of breath since the previous day. With his 3 sons, he was engaged in the repair work of an attic of an old building and had cleaned the accumulation of bird and bat droppings in the attic. What are we worried about?
Histoplasma
A 40-year-old resident of the US was brought to the urgent care center with a 4-day history of fever, chills, headache, sweating, and prostration. 2 weeks ago he had returned from a trip to Haiti. Blood films stained by Giemsa were positive for parasites. Erythrocytes in the blood film appeared normal in size and intraerythocytic delicate ring forms and crescent shaped gametocytes were seen. Some of the ring forms had double chromatin and multiple rings were observed in some RBCs.
Plasmodium Falciparum
A 38-year-old woman was treated for chronic myelogenous leukemia, with an allogeneic bone marrow transplant. She was released from the hospital with prescriptions for cyclosporine and steroids. She was readmitted 5 weeks after the transplant, noting abdominal cramping, nausea, and watery diarrhea. Over the last 2 weeks, she had developed a skin rash on her hands and feet, and the rash had spread to other parts of her body, peeling and blistering, giving her skin the appearance of severe sunburn. Physical examination revealed mild jaundice. Bloodwork showed elevated levels of bilirubin, SGOT, and alkaline phosphatase.
Acute graft vs host disease
A 45-year-old woman presents with a 2-day history of abdominal cramps and bloody diarrhea. She has just returned from her vacation in India, where she ate many of the local foods. Her blood pressure is 120/80 mmHg, pulse rate is 84/minute, and temperature is 37.8°C. What are on our differential?
Shigella Dysenteriae
A previously healthy 24-year-old woman presented with high fever of sudden onset, severe myalgia, headache, vomiting, diarrhea, and diffuse rash resembling sunburn. She was on the 4th day of her menses and was using tampons. Her blood pressure was noted as 70/40. As part of laboratory investigations, blood, urine, and vaginal cultures were done. Name bacteria, toxin
Staph aureus. Toxic shock syndrome toxin 1.
A 45-year-old woman presents with a 1-month history of headache with low-grade intermittent fever accompanied by nausea, vomiting, and altered mental status. Her previous medical history was significant for lupus erythematosis diagnosed 5 years ago, for which she was receiving chronic steroid therapy. On examination, the patient appears confused; her temperature is 39°C and she has neck stiffness. What are we worried about?
Cryptococcus
A 32-year-old office worker at the Venezuelan embassy was admitted to The George Washington University Hospital following a grand mal seizure. During his youth he had experienced seizures that included numbness of the upper left extremity, unconsciousness, and residual left-side headaches. He had not experienced such symptoms for many years until they resurfaced several months ago when he recalled similar progressive weakness, sharp pain in his upper left arm, blurred vision, and motor disturbances. An encephalogram revealed calcification in the third ventricle. This disease is caused by which of the following parasite?
Neurocysticercosis. Taenia Solium
A 26-year-old woman presents with a 3-day history of right knee pain; her knee is red, hot, and swollen. In addition, she reports a skin rash and mild pain in her wrists that has been present for the past 2 days. Temperature is 101.6° F, BP is 130/80 mm Hg, P is 98/min, and RR is 12/min. She is sexually active with 2 different partners. Physical exam reveals an erythematous, swollen, tender right knee joint, and bilateral pustules on her wrists. She states that she has a history of recurrent bouts of infections. A preliminary diagnosis of septic arthritis is made. The clinician suspects that the patient has some type of immunodeficiency. What complement deficiency is most likely associated with the dissemination of the causative agent in this patient?
C5b - C9
A 12-year-old boy presents with an elevated body temperature of 39.9°C. He has a history of fishing and playing in the woods with his dog in areas of high grass. Other than his current illness, there is nothing remarkable in his medical history. Physical examination reveals an acutely ill child with a notable macular rash on his lower extremities and palms. The patient had experienced severe joint pain and intermittent bouts of diarrhea. What are we suspecting?
Rickettsia rickettsii
A 36-year-old woman presents to her primary care physician after a tick bite. She reports having hiked in Alabama last week and found a tick on her arm after the hike. She denies having any rashes. One day ago, she started having subjective fevers, headache, nausea, and vomiting. Her physical exam is unremarkable and does not have any maculopapular rashes or targetoid lesions. A peripheral blood smear shows monocytes with morulae in the cytoplasm, confirming the diagnosis.
Ehrlichia chaffeensis
A 42-year-old man with a history of HIV presents with blurred vision. The patient also notes occasional small spots in his vision. The patient is non-compliant with his medications. Physical examination reveals vital signs of temperature 100.8°F, BP 114/80 mm Hg, RR 12/min, and pulse 76 BPM. Decreased visual acuity, as well as loss of peripheral vision, is demonstrated. Blood work is notable for a CD4 count of 30 cells/mm3.
CMV retinitis
A 24-year-old woman presents after a 3-day history of fever, headache, and vomiting. Her roommate reports that the patient first described smelling strange odors, and she then could not remember where she was or her name. Examination reveals an aphasic patient with a temperature of 39°C. CBC of the peripheral blood is normal. Patient develops seizures. An MRI reveals significant edema and necrosis of the left temporal lobe, with involvement of the left basal ganglia. What virus is the cause of this?
HSV-1