MICRO

Question 1

What is sepsis?

Answer 1

An infection triggering a host response that leads to organ dysfunction

Question 2

How are patients with sepsis recognized?

Answer 2

By recognizing organ dysfunction, such as :

• > 2mmol/L lactate
• systolic blood pressure >90 or MAP <65
• need for oxygen to achieve more than 90% saturation
• creatinine >170 micromol/L
• bilirubin > 32 micromols\L
• acutely altered mental status

Question 3

Cell tropism

Viral affinity for specific body tissues (tropism) is determined by?

Answer 3

• cell receptors for virus
• cell transcription factors that recognize viral promoters and enhancers sequences
• ability of cell to support virus replication
• physical barriers
• local temperature, pH and oxygen tension enzymes
• digestive enzymes and bile in GI tract that may inactivate some viruses

Question 4

Oncogenic viruses in hepatocellular carcinoma?

Answer 4

Hep B and C

Question 5

Oncogenic virus in cervical cancer?

Answer 5

Papillomavirus

Question 6

Oncogenic virus in lymphoma?

Answer 6

HIV and EBV

Question 7

Oncogenic virus in nasopharyngeal cancer?

Answer 7

EBV

Question 8

Oncogenic virus in kaposi’s sarcoma?

Answer 8

HIV with HHV8

Question 9

T cell leukemia oncogenic virus?

Answer 9

HTLV-1

Question 10

Classes of antiviral agents?

Answer 10

• agents that deactivate the virus directly eg. UV, cryotherapy
• agents that augment the host response eg. interferon
• agents that inhibit viral replication eg. acyclovir

Question 11

How do you examine the cells for the effect of viral growth?

Answer 11

Cytopathic effect

Haemabsorption (cells acquire the ability to stick to mammalian red blood cells)

Question 12

Common cause of community acquired sepsis?

Answer 12

Neisseria meningitidis

Question 13

Common cause of community acquired meningitis?

Answer 13

Neisseria meningitidis

Question 14

Patient risk factors for invasive meningiococcal disease?

Answer 14

Splenectomy, hyposplenism
HIV
complement deficiency
Properdin deficiency
Young age
Acute viral respiratory infection 
Extreme fatigue

Question 15

Treatment of invasive meningiococcal disease?

Answer 15

Antibiotics
Fluid replacement
Correction of coagulation abnormalities
Critical care if organ failure present such as ventilation and dialysis

Question 16

Waterhouse-Friderichsen syndrome?

Answer 16

Waterhouse-Friderichsen syndrome is characterized by the abrupt onset of fever, petechiae, arthralgia, weakness, and myalgias, followed by acute hemorrhagic necrosis of the adrenal glands and severe cardiovascular dysfunction. The syndrome is most often associated with meningococcal septicemia but may complicate sepsis caused by other organisms, including certain streptococcal species. This disorder may be associated with a history of splenectomy.

Question 17

Pathogenesis of meningococcal disease

Answer 17

Capsule hides its immunogenic outer membrane protein

LOS acts as an endotoxin which causes:

• increased vascular permeability
• pathological vasoconstriction and vasodilation
• loss of thromboresistance, activating coagulation system leading to DIC
• damage to blood cells lead to profound shock as well as skin lesions and thrombosis
  Myocardial infarction may occur

Sign of meningiococcal septicemia is the glass test, rash doesnt fade when you apply pressure to the skin

Question 18

Stages of whooping cough?

Answer 18

Catarrhal stage
1-2 weeks
Nonspecific symptoms such as generalised malaise, rhinorrhea and mild cough.
THE MOST INFECTIOUS STAGE

Paroxysmal stage
2-4 weeks
Paroxysmal cough- sever, vigorous coughs that occur during a single expiration followed by vigorous inspiration- whooping sound

Convalescent stage
3-4 weeks
Gradual reduction in the frequency and severity of cough
The total duration of all three phases is typically about three months

Question 19

Managment of diphtheria?

Answer 19

Give diptheria antitoxin
Antibiotics such as penicillin/ erythromycin
Airway management/ ECG and enzymes/ neuro
Droplet precautions
Notifiable infection- contacts

Follow up:
Cultures —> To ensure eradication
Immunization during their convalescent stage since natural infection does not reliably induce immunity

Question 20

Schedule of DTaP?

Answer 20

2,4,6 months
Booster at 4-5 years
Booster at 12-14 years

Efficacy at 95%

Question 21

Describe Corynebacterium jeikum

Antibiotic?

Answer 21

Colonise the mucosa and skin, very antibiotic resistant
Occurs in immunocompromised patients especially with hematological malignancy

IV LINE INFECTIONS

bacteraemia, endocarditis, abscess

Treatment- glycopeptide

Question 22

Describe C ulcerans

Answer 22

Bovine mastitis
Infection from infected animals or contaminated milk
Causes pharyngitis
Treatment is erthromycin

Question 23

Describe C minitussimum

Answer 23

Erythrasma at toe web, groin, axilla

Fluorescent wood’s lamp

Erythrasma is a superficial skin infection that causes brown, scaly patches

Question 24

People at risk for listeria monocytogenes?

Answer 24

Occupational
Perinatal
Immunocompromised patients

Question 25

Pathogenesis of listeria

Answer 25

Can cross mucosal membrane barrier and disseminate
It can survive within macrophages and multiply there.
It can spread from cell to cell without exposing itself to the extracellular environment

It needs a T cell response to activate infected cells and produce intracellular killing

Question 26

Diagnosis of brucella?

Answer 26

Clinical suspicion

Lab investigations such as blood cultures, more than one set, up to 6 weeks incubation (biosafety level 3)
Bone marrow aspirate

Serology
- serum agglutination (SAT ), complement fixation, Coombs test titre >1:160

PCR blood

Question 27

Treatment of brucellosis

Answer 27

Doxycycline and rifampicin for 6 weeks

PREGNANT PATIENTS AND CHILDREN INTOLERANT TO DOXYCYCLINE
so give cotrimoxazole and rifampicin