Lecture: Infectious Diseases

Infectious disease → Importance  Prevalence ♣ Morbidity and mortality ♣ All worlds ♣ Between worlds → Importance  Prevalence  Preventable/curable  Alarming → Objectives  Appreciate its importance  Describe the factors involved  State the steps in diagnosis ♣ (the approach to an ambulatory febrile patient)  Describe its management → Outline  Importance  Definitions  Factors  Steps in diagnosis  Approach to the ambulatory febrile  Normal body temp  Fever  Management principles → Definition  Contamination  Invasion  Infection → Factors in Infection  Host ♣ Susceptibility vs defenses  Innate  Adaptive  Cellular  Humoral  Pathogen ♣ Virulence and resistance ♣ Emerging organisms  encounter Steps in the Diagnosis (Approach to the Febrile Patient) → History → General Data  Name, age, gender, occupation, addresses, contact number (px as a person) → Chief complaint – direction → Present Illness  Symptoms  Course  Remedies → Illness Syndrome → Past  Illness and tx, contacts, dietary preferences, habits – predisposition and exposure → Family  Genetics, environmental, predisposition, healthcare support

Steps in dx → history  establish 3 factors → PE Physical examination → vital signs → fever → localizing signs Fever → normal body temp 36.5 – 37.7 oral → + 0.4 rectal → + 0.8 tympanic → Circadian rhythm → Highest in the pm, lowest in the am → Incr with meals, ovulation, str exercise → Regulation of body temp → Hypothalamus  Need heat: shiver  Need to lose heat: inc blood to skin and soft tissue, sweat Elevated temp → physiologic conditions → pathologic conditions  hyperthermia ♣ reduce by physical means  fever ♣ exogenous pyrogens –WBC ♣ endogenous pyrogens (cytokineshypothalamus) Fever → infections → immune and ct dx → neoplastic → Inflammation, infarction and trauma → Granulomatous disorders → Metabolic disorders → Others Steps in Diagnosis → Hx → PE → Lab exam  CBC  Clin path and radiology  Bacteriology and Parasitology Identify cause → direct means : smear, culture → indirect means: antibody titer, histopath, PCR Management → specific (curative)  diagnosis first, unless life threatening → symptomatic  adjuvant tx, relief of symptoms, diet, fluids, rest → preventive Reminders → a patient is a person who asks for and/or needs help → a doctor provides competent holistic humane care with respect for the dignity of the person