infectious disease emergenecy

Question 1

name 4 infectious disease emergencies

Answer 1

• Sepsis and septic shock
• Severe malaria
• Severe community acquired pneumonia
• Bacterial meningitis

Question 2

what is sepsis ? how is it diagnosed

Answer 2

overwhelming inflammation (extreme responce of the body to infection ,causing life-threatening organ dysfunction -> there muclinical evidence of inection together with 2 or more “Sequential [Sepsis-related] Organ Failure Assessment score (qSOFA):”
- Altered mentation (Glasgow Coma Scale <15)
- Respiratory rate ≥30/min
- Systolic BP ≤100 mm Hg

Question 3

explain what septic shock is

Answer 3

• Septic shock is sepsis with hypotension (systolic BP <90 or >40 fall in systolic BP) persisting despite fluid challenge

Question 4

How is the severity of severe community-acquired pneumonia assessed?

Answer 4

use the CURB -65 scale :
1. Confusion
2. Urea elevated (>7 mmol/L)
3. Respiratory rate >30/min
4. Blood pressure low (systolic <90 or diastolic ≤60 mmHg)
5. 65 age ≥65
- Score 1 point for each - can also be done without the urea (CRB-65 score)

The CURB score is: score-mortality-action
0 or 1->1.5%->may be suitable for outpatient therapy
2->9.2%->hospitalise
3->22%->treat as severe CAP

The CRB score: score->mortality ->action
0->1.2%->may be suitable for outpatient therapy
1or 2->8.2%->hospitalise
3 or 4 ->31%-> treat as severe CAP

Question 5

what are causes of CAP?

Answer 5

1. Aytipical bacteria : mycoplasma pneumoniae,chlamydophila pneumoniae,legionella spp
2. conventional bacteria :Strptococcus pneumoniae,Haemiphilas influenzae ,Klebsiella pneumoniae,Moraxella catarrhalis ,Staphyloccus aureus .
3. Viruses

Question 6

explain the management of severe CAP

Answer 6

-Antimicrobials must be commenced intravenously (can switch to PO once improving).
-Broad spectrum -lactam (to cover Gram+ & Gram- conventional bacteria)
PLUS
-Macrolide (to cover “atypical” bacteria)
-Oxygen if saturation <94%
-Other resuscitative measures

Question 7

what is community acquired pneumonia ?

Answer 7

pneumonia that is acquired outside hospital in a person who is not immunocompromised .

Question 8

what is the clinical presentation - CAP?

Answer 8

• vgest pain
  -wet/dry cough
  -dyspnoea
  -fever
• lung consolidation : dullness on percussion , increased vocal resonance

Question 9

what is the difference between lober and bronchopneumonia in terms of the areas of the lung that are affected ?

Answer 9

• lobar -> affects/the consolidation is the lung parenchyma .
  due to the inflammatoy peocess going on , the alveola is filled with fliud, immune cells ,pus
  -bronco- the site of consolidation is mainly along the airway .

Question 10

explain the lifecycle of malaria

Answer 10

-plasmodium -infected female anopheles mosquito hunts for blood meal in the evening and through the night
- bites a person
the Plasmodium is in a stage of development called the sporozoite waiting patiently in the mosquitos salivary gland .
-through the bite ,sporozoites spill out of the mosquito saliva and make it into the bloodstream .
- the sporozoites reach the liver and mount an attack on the hepatic parenchymal cells= where they start asexual reproduction
-at this point the Plasmodium species vary a bit over the next one to two weeks Plasmodium falciparum plasmodium, malariae and Plasmodium Knwolese->sexual reproduction
- it’s generally asymptomatic
->released into the blood and they infect RED (undergoe other 3transformational changes and asexual reproduction inside the cell)->early trophozoite(ring)->late tropozoite->schizont
- mitosis ->defferentiation into merozoites -> get released to blood ->some merozoites undergo gametogony
- another mosquito takes a bite o the infected person

Question 11

list features of severe malaria

Answer 11

-Decreased level of consciousness
-Seizures
-prostration (inability to drink or sit unaided )
-Shock
-Acidosis
-Severe anaemia (Hb <7)
-visible jaundice
-renal impairment
-parasitaemia>/=5% of red cells
-hypoglycaemia
-Respiratory distress

Question 12

who are people at risk of severe malaria

Answer 12

1.In endemic areas (year-round transmission):
-Young children
-Pregnant
-HIV+
2. All people from areas without malaria or with seasonal malaria

Question 13

what is the mostly cause of the malaria infection ?

Answer 13

Nearly always Plasmodium falciparum infection

Question 14

Explain the management of severe malaria

Answer 14

-If uncertain about criteria of severe malaria or you have a patient you feel concerned about not meeting criteria: treat as severe-> you can always reduce the dose after
-Must use intravenous therapy
-Drug of choice =Artesunate
-Cautious with fluids (over-hydration can cause respiratory failure

Question 15

what type of rash do you get in Bacterial meningitis ?

Answer 15

non-blunching petechial rash

Question 16

what is the strongest predictor of outcome in bacterial meningitis when treatment is started ?

Answer 16

Strongest predictor of outcome in bacterial meningitis is the level of consciousness when treatment is started
-Consciousness can decrease rapidly

Question 17

what is the best time to start antibiotics in bacterial meningitis ?why ?

Answer 17

-as early as possible (if you are strungle with LP start with the treatment and you can do the LP later )
- delayed treatment is associated with mortality and unfavourable outcome .

Question 18

what are the likely organisms to cause meningitis in children <1 month? comment whether they respond to Ceftriaxone

Answer 18

• Streptococcus agalacticae (responds +)
  -Aerobic Gram-negative bacilli (+)
  -Listeria monocytogenes (rare in SA)(-)

Question 19

what are the likely organisms to cause meningitis in children 1-24 months? comment whether they respond to Ceftriaxone

Answer 19

-Neisseria meningitidis
-Streptococcus pneumoniae
-Haemophilus influenzae ( decrease with vaccination)

(all responsive )

Question 20

what are the likely organisms to cause meningitis in people 2-50 years of age ? comment whether they respond to Ceftriaxone

Answer 20

-Streptococcus pneumoniae
-Neisseria meningitidis
(both responsive )

Question 21

what are the likely organisms to cause meningitis in people >50 years of age ? comment whether they respond to Ceftriaxone

Answer 21

Responsive :
-Streptococcus pneumoniae
-Aerobic Gram-negative bacilli
not responsive :
Listeria monocytogenes (rare in SA)