Summary of Infectious Diseases

Question 1

Infection disease history includes

Answer 1

Epidemiological history

PMH

Question 2

Epidemiological history

Answer 2

Travel, vaccine, prophylaxis history, occupation, food/drink, recreational, sexual, animal contact, medical procedures

Question 3

Travel - most common issues… due to?

Answer 3

Diarrhoea due E.coli, salmonella, campylobacter, viral

Respiratory tract infections - viral, legionella

Urinary tract infections

Skin/soft tissue infections
- insect bites

Hep A, Ebola, avian flu, e.g middle eastern respiratory syndrome

Question 4

Infectious diseases related to travel

Answer 4

Malaria - needs blood test if they have a fever 
Typhoid
Dengue 
VHF
Bird flu

Question 5

Prophylaxis and vaccines

In general ask about

Answer 5

Malaria for recent travel

Neisseria, typhoid, Hep A, Hep B (useful for infection control)

childhood schedule

Question 6

Occupational hazards

Answer 6

Sex workers - HIV, HEPB, AIDS, STDs
Pet shop owners
Health care - BBV, diarrhoea, LRTIs

Farmers - leptospirosis, ORF, coxiella

Sewage workers - gastroenteritis, leptospirosis
Military - malaria

Question 7

Sexual history

Answer 7

• Recent partners – new? • Number of partners
• Male or Female or Both • CSW?
• Use of condoms
• Travel sexual history (of index and partner)
• STI’s? STI screens?
– HIV, Hepatitis B, EBV, CMV, gonococcus, chlamydia, syphilis, HSV, also urinary tract infection

Syphilis - snail track ulceration and poor dental development in congenital disorders

Question 8

Sport risks and examples

Answer 8

• Canoeists
– Leptospirosis, gastroenteritis • Cavers
– Histoplasmosis, Marburg • Trekkers
– Lyme Disease, other Tick-borne diseases • Rugby Players- herpes gladiators
– HSV, fungal infections • Swimmers
– Fungal infections, pox viruses, Leptospirosis, gastroenteritis

Question 9

Drug abuse risks

Answer 9

•  IV Drugs
– Hepatitis C, Hepatitis B, HIV, Endocarditis, Skin & Soft tissue infection including anthrax, aspergillus
•  Alcohol
– TB, pneumonia, HIV
•  Cannabis
– Pneumonia, early COPD, lung abscess

Question 10

Pets

Answer 10

•  Dogs
–  Campylobacter species, Toxocara, rabies
•  Cats
–  Toxoplasma
•  Rodents
–  Rat Bite Fever, salmonella
•  Terrapins
–  Salmonella
•  Psittacine Birds
–  Chlamydia psittaci
•  Tropical Fish
–  Mycobacterium marinum
•  Wild and Domestic Fowl –  Avian influenza
•  Agricultural animals (city farms etc)
–  Coxiella spp, salmonella, E.coli (eg 0157)

Question 11

Relevant PMH

Answer 11

• Head Injury
– Meningitis (especially pneumococcal)

• Cancer - very immunpsuppressing condition

• Use of immunosuppression
– CMV, VZV, PCP, neutropenic sepsis (bacteria, fungi)

• Splenectomy
– Pneumococcal bacteraemia

• Dentistry
– endocarditis

• Previous history of infectious disease
– Especially meningitis, pneumonia, cellulitis

Question 12

Risks during special medical procedures

Answer 12

• Blood Transfusions/Blood products
– HIV, HBV, HCV, malaria!, prions
• IV cannula
– Skin and soft tissue sepsis (bacterial)

•  Prosthetic joints or heart valves
–  Serious persistent bacterial infections 
•  IUCD
–  actinomycosis
•  Body piercing –  Skin sepsis

Question 13

Contact risks

Answer 13

• Tuberculosis
• Sexually transmitted infections including HIV
• Meningococcal Disease
• Shingles, Chicken Pox
• Measles, Rubella, Mumps
• Diarrhoea (viruses, food borne outbreaks)

Question 14

Serological response to HepA

Response to infection - 3 types

Answer 14

Antibody conc increases
Systemic
Local
Specific

Question 15

Systemic response

Answer 15

Fever malaise
Lymphadenopathy 
Vital signs 
WBC count 
Rashes e.g Weil's disease --> conjunctivitis also

Question 16

Local response

Answer 16

Tumor
Rubor
Calor
Dolor
= INFLAMMATION 
Destruction 
Abscess

Question 17

Specific response

Answer 17

Antibody (humoral) or cell mediated response

Question 18

Principles of infection history

Answer 18

• Epidemiologicalhistory • Travel,
• vaccineandprophylaxishistory, • occupation,
• food/drink,
• recreational,
• sexual,
• animalcontacts,
• specialmedicalprocedures, • Unwellcontacts.
• PMH
• relevanttoinfectiousdisease

Question 19

Principles of Infection Exam and Tests

Sterile site

Non-sterile

Answer 19

Isolate pathogen

Blood, CSF, urine, bone/joint - taking from sterile site eliminates other sources of infection

Skin, gut, respiratory tract

Question 20

Conventional history

Answer 20

Presenting complaint
History of PC
Epidemiological history 
Previous medical history 
Dental history 
Family history 
Sexual history 
Systemic enquiry

Question 21

Diagnosing infection
methods

detecting specific immune response e.g hep a serological response

Answer 21

Isolate
Stool Sample
Swab 
Sputum 
Blood test 

1. exposure to HAV
2. anti-HAV IgM developing during incubation period (non-specific)
3. IgG specific antibody is now developed

Acute infection if IgM can be seen but no IgG yet

tuberculin skin test - HEaf - test for cell mediated response of first exposure to TB

• if goes red it’s +ve
• if it doesn’t it is -ve