--- module: 060-02 language: en chapter: 60 title: "Occupational, Travel, and Population Infection Risks" module_title: "Exposure reconstruction, travel syndromes, worker protection, and public-health action" source_sha256: 332eb4336918fd4a57f55087bf73ce7d50bb4e082017a38460d3cd609eeb780a --- # Exposure reconstruction, travel, and public-health action ## Reconstructing exposure ### Exposure, not job title or destination #### Same employer, different hazard #### Same country, different season, altitude, contact ### Agent, route, intensity, duration, timing ### Change away from the environment ### Actual tasks, trade names, processes ### Timeline: pre-employment, process change, leave ### Confidentiality, independent of return pressure ## Hazard control and surveillance ### Protective equipment is the least reliable barrier #### Eliminate, substitute, engineer, administer #### Depends on selection, fit, training, use ### Surveillance detects change, not unfitness #### Group decline: investigate the process ### Normal test does not justify exposure ### Return to work addresses re-exposure and control ## Respiratory hazards ### Occupational asthma: sensitiser or irritant #### Weekend improvement lost once persistent #### Delay leaves permanent hyperresponsiveness ### Silica activates macrophages #### Nodular fibrosis, tuberculosis, autoimmunity #### Dry cutting of engineered stone ### Asbestos disease after decades #### Smoking multiplies lung-cancer risk ### Primary prevention beats surveillance ### Hypersensitivity pneumonitis #### Precipitins show exposure, not disease #### Ask about humidifiers, pets, hobbies ## Skin, noise, and vibration ### Irritant: wet work, solvents, glove occlusion ### Allergic: delayed T-cell, spreads past edge #### Patch testing, not skin-prick ### Noise: hair-cell loss is irreversible #### Speech in background noise fails first ### Source control outranks hearing protectors ### Audiometry detects but does not prevent ### Vibration: blanching, numbness, dexterity loss ## Needlestick exposure ### Wash, irrigate, report, characterise ### Prompt human immunodeficiency virus prophylaxis ### Hepatitis B by vaccination and antibody ### Hepatitis C: early follow-up allows cure ### Negative source may miss recent infection ### Follow-up timing follows marker biology ### Blame-free reporting learns from near misses ## Pre-travel planning ### A risk plan, not a vaccine transaction ### Routine immunisation before destination vaccines ### Live vaccines in pregnancy, immune suppression ### Medicines in original packaging, in surplus #### Drugs dangerous during dehydration ### Postpone if chronic disease unstable ## Travel syndromes ### Malaria prophylaxis before and after travel #### Before: tolerance and therapeutic levels #### After: parasites emerging from the liver ### Dengue: leak around defervescence #### Warning: haematocrit up, platelets down #### Titrate fluid: shock versus overload ### Diarrhoea: oral rehydration first #### Loperamide not alone with dysentery #### Beyond two weeks: Giardia, other protozoa ### Rabies: wash wound, never delay treatment #### Symptomatic rabies almost uniformly fatal ### Altitude illness: hypobaric hypoxia #### Gradual ascent permits adaptation #### Descend; sedatives and ascent dangerous ## The returned traveller ### Immediate threat and isolation first ### Fever with thrombocytopenia differential ### Jaundice: hepatitis, haemolysis, leptospirosis ### Isolate and protect from point of entry ### Sepsis care parallel to specific diagnosis ### One negative test does not close disease ### Transit, funerals, caves, animals, sex ## Migration and outbreaks ### Migration history not a proxy for biology ### Interpreters and individual evidence ### Cluster recognition prevents for many #### One rare case may require action #### Notify before complete confirmation ### Case definition, line list, exposure map ### Isolation versus quarantine ### Genomic similarity supports, not proves ### One Health: animals, food, climate, water ### State known, unknown, action, next update #### Case counts need denominator and method