History Taking In Infectious Diseases 51w4l

ID teaching notes History taking in Infectious Diseases (introductory lecture) This is similar to any other speciality, but certain areas are of particular importance, especially seeking risk factors for infection. Presenting complaints A reminder of some general points: Initially allow the patients to tell their own story Ask for clarification if need be by asking simple questions. Avoid leading questions Each major symptom needs to be analysed in detail e.g. Diarrhoea: severity, duration, frequency, consistency, colour / presence of blood, associated features e.g. Fever: duration, frequency, temperature recordings, night sweats, rigors, associated features If the patient provides a diagnosis for their symptoms, e.g. 'flu, ask for clarification as this might include a variety of different symptoms Clarify the timing of any exposure to start of symptoms - this gives possible timing of incubation which may include or exclude certain infections (e.g. return from travel 6 weeks before symptoms would exclude short incubation infections such as dengue fever - 4 days)

Past Medical History Ask about previous infections • frequent severe infections might suggest underlying immunosuppression • some infections might produce lifelong immunity e.g. measles, others a risk of reactivation e.g. herpes viruses • sexually transmitted infections • healthcare associated infections e.g. MRSA, C difficile Systematic enquiry Ask about specific symptoms for each body system - don't forget skin & ENT Ask about symptoms of fever - rigors, night sweats to check whether female patients could be pregnant • some infections may cause more severe illness in pregnancy e.g. hepatitis E, chickenpox • some infections may cause danger to the fetus e.g. rubella • antimicrobial therapy may have to be adjusted Family History Are there relatives with a history of an infection which the patient might have caught? (e.g.TB) Are there relatives with a history of frequent severe infections suggesting an inherited immunodeficiency? Drugs : • Immunosuppression - e.g. steroids, methotrexate, cyclosporin • Antibiotics given recently - may show that current infection is due to resistant organisms, or increased risk of C difficile • Antacid drugs - reduce stomach acid so that ingested bugs are more likely to survive • Malarial prophylaxis for travel, including checking for adherence

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ID teaching - Introductory lecture – Infectious Diseases History

Vaccinations • Up-to-date? May have missed primary course • Evidence of response – e.g. hepatitis B vaccine response may be tested by checking for antibodies in healthcare workers • Prior to travel Allergies (especially medication) Antibiotic allergies: • Ask what actually happened when the patient took the drug in question. A mild reaction may not preclude giving the same class of antibiotics if the illness is severe • Vomiting, or other adverse effects, after an antibiotic sometimes gets labelled as an allergy - you might still want to avoid this antibiotic but others in the same class could be tried. Risk factors for infection (examples of infections in brackets) s • family, friends, workmates who might have infection • recent stay in a healthcare institution - may have been in with healthcare associated pathogens (e.g. MRSA, C difficile) Recent hospital procedure • surgical site infection • infections from invasive devices e.g. urinary catheter, iv lines Occupation • Food handlers i.e. handling raw food- also important because of Public Health risk of them spreading infection to others (salmonella, campylobacter) • Animal exposure - farmers, vets etc (leptospirosis, cryptosporidiosis) • Sewage workers (leptospirosis, hepatitis A) • Healthcare workers (viral gastroenteritis, blood-borne viruses, TB) Travel • When and where they went & when they got back? • What they did? o Sexual s (HIV, Hepatitis B, STDs) o Food & drink (GI infections, enteric fever, hepatitis A or E) o Accommodation including air conditioning (Legionnaire's) o Swimming in unchlorinated water (schistosomiasis, GI infections) • What precautions they took? o Vaccinations o Malaria prophylaxis and adherence to this o Mosquito nets / insect repellent • Were they or any one else ill Leisure activities • hiking (tick bites - Lyme disease) • canoeing & fishing (leptospirosis) Food history • food not properly cooked or stored (GI infections) • meals out including takeaways (GI infections) • shellfish (hepatitis A) • poultry (campylobacter, salmonella)

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ID teaching - Introductory lecture – Infectious Diseases History

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raw or undercooked eggs (salmonella)

Exposure to animals & birds • pets - their own and other people's (psittacosis, campylobacter) • farm visits (psittacosis, campylobacter, cryptosporidiosis) Risk factors for blood borne viruses (HIV, Hepatitis B or C) • injecting drug use - IDU • transfusion of blood products especially before screening for HIV/Hep C started (1980s) or overseas • amateur tattoos & body-piercing Sexual history (HIV, Hepatitis B, STDs) • unprotected sex • new partners • partners with high risk behaviour e.g. IDU • men who have sex with men

September 2012

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