Cases Flashcards
A young menstruating female experienced sudden onset of fever, diarrhoea, vomiting and red rash, plus hypotension with cardiac and renal failure. Onset of the disease was about 5 days from onset of menses. She was using vaginal tampons that were left in place for an extended period.
a) What is the most probable diagnosis?
b) What is the organism causing this conditions?
c) What is the pathogenesis of this disese?
d) Describe the laboratory diagnosis of this disease.
a) Toxic shock syndrome
b) Staphylococcus Aureus
c) Super antigen TSST-1 toxin travels in blood
d) Specimen collection, cultivation, identifications
A 55-year-old man who just arrived from Germany experiences attacks of bloody diarrhoea and abdominal cramps. He states that he had a hamburger sandwich with grenn salad. Culture of stools on Mac Conkey’s medium re veals a pure culture of rose pink colonies. Examination of Gram-stained film from these colonies shows Gram-negative bacilli.
a) what is the possible causative organism of this condition?
b) What is the virulence factor of this organism?
c) How can a definite diagnosis be reached?
d) What is tha most serious complication of this condition?
e) Mention other types of the same species that can cause diarrhoea
a) E. coli
b) Shiga-like toxin
c) PCR/ DNA probe
d) Hemolytic uremic syndrome
e) Enter-pathogenic, entero-hemorrhagic, entero-invasive, entero-aggravative
A 54-year-old man develops a pyogenic infection along the suture line after knee surgery, swab from the infected wound was sent to the laboratory for bacteriological examination. Direct smear revealed Gram-positive cocci amongst pus cells. Culture on blood agar showed growth of beta-hemolytic colonies that were catalase & coagulase positive.
a. What is the most likely causative agent?
b. Enumerate the virulence factor(s) of this organism?
c. Name two other diseases caused by this organism.
a) Streptococcus pyogenes
b) M protein, protein F, Lipoteichoic acid, invasives
c) Acute endocarditis and Necrotizing fasciitis
A 15 year-old-boy developed acute onset of nausea, vomiting and diarrhea, shortly after returning from an outdoor party. Cakes and ice cream were served. The boy’s symptoms started 6 hours after eating. He did not have any fever and no blood was seen in his stools or vomitus. Several other persons attending the party’ developed similar symptoms.
- What is the diagnosis of this case? Mention the causative organism.
- Mention the pathogenesis of this disease.
- What is the probable source of infection?
- Food poisoning. Staphylococcus aureus
- Preformed enterotoxin
3- Carbohydrate rich food
Three months ago, a 30-year-old pregnant nurse was injured by a needle-prick contaminated by blood from a patient with hepatitis B. Her laboratory investigations reveal the following results:
HBsAg absent
Anti-HBs antibody absent
IgM anti-HBc present
IgG anti-HBc absent
HBeAg absent
a) What is the interpretation of these laboratory’ results?
b) The nurse was concerned about her baby. Explain the risk the baby is exposed to.
c) Discuss the prophylactic measures to protect the baby.
a) This is the window phase
b) The infection can get progressively worse —–> baby has weak immune system
c) Hepatitis B immunoglobulin
A mother took her 7-year-old boy to the park. While playing, the child disturbed a bee nest. The boy was stung by the angry bees. Within minutes he went into shock, manifesting respiratory failure and vascular collapse. The mother gave a history of previous exposure of her child to bees before.
1) What is the most likely diagnosis of the boy’s condition?
2) What is the underlying immunological mechanism?
3) What are the immediate therapeutic measures to control his condition?
1- Hypersensitivity reaction (Type I)
2- Exposure to bees—-> IL-4 drives B-cells to produce IgE against bees—-> IgE reacts to 2ndry bee exposure ——-> Acute release of mast cell causing allergic manifestations
3- Epinephrine pen + Corticosteroids
A 25-year-old female patient who has suffered from severe, disabling arthritis for several years presents with the joints in her hands distorted due to the severity of the inflammation. She is diagnosed with rheumatoid arthritis.
a) What are the laboratory tests that led to such a diagnosis?
b) Explain the immunological mechanisms involved in the pathogenesis of this discase?
a) No test diagnostic/ modified jones criteria
b) M protein cross react with antigens of joints, heart
A 50-year-old man was spending his vacation with his family in India, where cholera is known to be endemic. One week after his arrival he experienced profuse watery diarrhea and vomited several times. On examination he was found to have low blood pressure and 3 rapid heart rate. A diagnosis of cholera was suspected.
a) What is the causative organism of this disease?
b) What is the virulence factor of the organism?
c) How can a definite diagnosis be reached?
d) What is the proper treatment of this patient?
e) Knowing that this patient’s wife has been taking antacids for treatment of gastritis, does this affect her susceptibility to contract infection? Explain your answer.
a) Vibrio cholera
b) Enterotoxin
c) Cultivate specimen and identify
d) replace fluids + electrolytes + antibodies
e) Yes, cholera cannot survive in high stomach acidity; antiacids lowered the acidic
A 32-year-old pregnant female presented to the clinic complaining of fatigue, chronic diarrhea and weight loss over the past weeks. She also had a purple abdominal lesion which was diagnosed as Kaposi sarcoma. Laboratory investigations revealed reduced CD4 T cell count. The patient gave a history of blood transfusion 7 years ago during a radical operation.
a) What is the most likely diagnosis and what is the aetiologic agent?
b) How did the patient most probably contract this infection and what are the other modes of transmission?
c) Name the laboratory tests done to reach a definite diagnosis.
d) What are the measures that should be taken to prevent matemo-foclal transfer?
a) Human Herpes Virus-8
b) Sexually
c) IgG Elisa, viral DNA PCR
d) Anti- viral drugs
A 62-year-old male patient suffering from chronic renal failure undergoes a surgery for renal transplantation. The donor is his sister. Despite the immunosuppressive therapy taken by the patient, 4 years later the transplant is rejected.
a) Mention the type of this rejection and the underlying mechanism.
b) What is the type of this graft?
c) Mention 2 methods for tissue typing.
d) Mention one of the immunosuppressive drugs that may be given to such patients and its action.
c) What patients are more liable to experience this type of rejection?
a) Late rejection (Low grade cell mediated injection)
b) Allografts
c) Molecular HLA and serological HLA typing
d) Corticosteroids—–> anti-inflammatory
e) Patients who have chronic viral infections
A 20-year-old male presents to the emergency department complaining of profuse bloody diarrhea of two days duration after eating hamburger at a fast food restaurant. Culture of the feces on sorbitol MacConkey’s medium revealed the presence of non-sorbitol fermenting colonies.
a) What is the causative organism of this disease and the most likely serotype?
b) What is the virulence factor of this organism?
c) What are the possible complications of this disease?
d) What is the source of contamination of this meal?
a) E.coli
b) Shiga-like tocin
c) Hemolytic uremic syndrome
d) faecal contamination
A young man presents to the clinic complaining of sore throat and marked fatigue. On examination he is found to have swollen tonsils, cervical lymphadenopathy, palpable spleen and skin rash. Blood picture reveals a total leucocytic count of 21,000/cmm with atypical lymphocytes.
a) What is the most likely disease and the causative agent?
b) Mention the other laboratory tests that may be done for diagnosis?
c) What cells does the causative agent infect and what is the cause for the presence of atypical lymphocytes?
a) Glandular fever infectious mononucleosis
b) Detection of heterophil antibodies and specific antibodies
c) Virus infects B-lymphocytes—–> toxic T lymphocytes react against it —–> looks atypical now
