Prevention of Communicable Diseases

1. Prevention of Communicable Diseases • byDr. TK Au of UHS • MBChB, MRCP(UK), DPD(Cardiff), DCH(Syd)

2. Communicable diseases • Definition: diseases that can be transmitted and make people ill • Statutory notifiable diseases • According to the law, a doctor has to notify the Department of Health when he/she has the reasons to suspect his patient is suffering from the disease • Eg. Chickenpox, tuberculosis, avian flu, SARS

3. Communicable diseases • Diseases that can cause outbreak in institutions • Influenza-like illness • Acute gastroenteritis • Hand, foot and mouth disease (HFMD) • Acute conjunctivitis

4. Chain of Propagation of Communicable diseases

5. Contact transmission • Through direct body contact with the infected persons • Indirect through contact with objects contaminated by infective agents, eg sharing towels, combs and clothes • Example • Hand, foot, mouth disease • Acute conjunctivitis • Head lice • Scabies • Chickenpox

6. Droplet transmission • Inhale or contact of droplets expelled from the sick during sneezing, coughing, spitting and speaking • Subsequent touching of mucous membranes of the mouth, nose and the eyes with hands contaminated with infective agents • Eg. Influenza, common cold, pneumonia

7. Air-borne transmission • The infective agents float in the air for some time • Enter the body through the respiratory tract • E.g. Chickenpox, measles, pulmonary tuberculosis

8. Food/water-borne transmission • Through ingestion of contaminated food or water, or use of contaminated utensils • E.g. Viral gastroenteritis, cholera, hepatitis A

9. Break the Chain Early Detection, Isolation, and Treatment of patients Disinfection X X Build up Personal Immunity by Immunization and Healthy Lifestyle Good Personal and Environment & Food Hygiene

10. Personal Hygiene • The most important part of infection control as many diseases are transmitted through contact or droplet • Hand hygiene • Cough etiquette

11. Hand Hygiene – When? • Before touching the eyes, nose and mouth • Before eating or handling food • After using the toilet • When hands are contaminated by respiratory secretions, e.g. after coughing or sneezing • After touching public installations or equipment • e.g. escalator handrails, elevator control panels or door knobs • Before and after visiting hospitals • After making contact with animals or poultry • After handling garbage

12. Hand Hygiene – How? • Handwashing with soup and water • When hands are visibly soiled • When hands are likely contaminated with body fluid • e.g. after using the toilet, after coughing or sneezing • Use of 70-80% alcohol-based hand rub

13. Use of 70-80% alcohol-based handrub • Apply a palmful of handrub • Use at least 20s to rub all surfaces of hands and fingers • Until the hands are dry

14. Personal Hygiene • The most important part of infection control as many diseases are transmitted through contact or droplet • Hand hygiene • Cough etiquette • Other

15. Cough Etiquette • Cover both the nose and mouth with tissue paper when coughing or sneezing • Do not spit • Wrap up sputum with tissue paper and discard it into garbage bin with lid or flush it away in the toilet • Wash hand immediately • Put on a surgical mask if you have respiratory infection symptom

16. Environment hygiene • Regular cleansing and disinfection • Maintain good indoor ventilation – open windows widely • Keep worktops n the kitchen clean • Cover garbage bins • Wrap up rubbish properly before discarding it into garbage bins • Empty garbage bins at least once a day • Do not keep pets like dogs, cats, or birds in hall

17. To stop perpetuation of communicable diseases Early Detection, Isolation, and Treatment of patients Disinfection X X Build up Personal Immunity by Immunization and Healthy Lifestyle Good Personal, Environment & Food Hygiene

18. Build up Immunity • Vaccination • Tuberculosis (BCG vaccine) • Hepatitis A & B • Diphtheria, Pertusis, Tetanus • Measles, Mumps, Rubella • Chickenpox • Pneumococcal • HPV • Others – before travel • Healthy lifestyle

19. Build up Immunity • Healthy lifestyle • Enough rest/sleep • Regular exercise • Balanced diet • Maintain a normal body weight, i.e. BMI 18.5-23 • Do not smoke

20. To stop perpetuation of communicable diseases Early Detection, Isolation, and Treatment of patients Disinfection X X Build up Personal Immunity by Immunization and Healthy Lifestyle Good Personal, Environmental, Food Hygiene

21. Bleach • Active ingredient: sodium hypochlorite (次氯酸鈉) • Action: denatures protein in virus, bacteria and fungus • Pros: Works quickly, widely available, low cost • Cons: • Irritates mucous membranes, skin and airway • Decomposed under heat or light • Reacts readily with other chemicals

22. Use of Bleach – Tools and Equipment • Cleansing tools: brush, mop, towel, spray can and bucket • Cleansers/disinfectants: bleach and water • Measuring tools: tablespoon and measuring cup • Protective gear: mask, rubber gloves, plastic apron and googles (recommended)

23. Use of Bleach - Procedures • Keep windows open, ensure good ventilation • Wear protective gear • Use COLD WATER for dilution • hot water decomposes the active ingredient of bleach • Bleach with 5.25% sodium hypochlorite • 1 in 99: mixing 10ml of bleach with 990ml of water, for general household cleaning • 1 in 49: 10ml of bleach with 490ml of water, disinfect surfaces or articles contaminated with vomitus, excreta and secretion

24. Use of Bleach - Procedures • Rinse disinfected articles with water and wipe dry • Cleansing tools • soak in diluted bleach for 30mins • rinse thoroughly before reuse • Wash hands with liquid soap, dry hands with a clean towel or disposable towel

25. Use of Bleach - Precautions • If bleach gets into the eyes, immediately rinse with water for at least 15 minutes and consult a doctor • Bleach should not be used together or mixed with other household detergents • Reduce effectiveness • If mixed with acidic detergents -> toxic gas • Bleached should be stored in a cool and shaded place • Undiluted bleach liberates a toxic gas when exposed to sunlight

26. Disinfection • Regular cleansing and disinfection of • Rooms, kitchen, toilets, bathrooms • Door knobs and lift buttons • Frequently touched surfaces – furniture, computer keyboards • For obvious contaminants e.g. respiratory secretions, vomitus or excreta • Wipe away with disposable towels • Disinfect the surface and neighboring areas with appropriate disinfection • Non-metalic surface – 1:49 bleach • Metalic surfaces – 70% alcholol

27. To stop perpetuation of communicable diseases Early Detection, Isolation, and Treatment of patients Disinfection X X Build up Personal Immunity by Immunization and Healthy Lifestyle Good Personal, Environmental, Food Hygiene

28. Early Treatment • Seek and follow medical advice immediately if you feel unwell

29. Early Isolation • Stay at home and do not attend school if your doctor tell you to do so. This is usually when one is • Febrile (Ear temperature ≥ 38˚C) • Suffering from chickenpox, hand-foot-mouth diseases, measles, certain form of tuberculosis • Minimize contact with other people as far as possible. Avoid group activities. • Maintain good personal hygiene • People with respiratory infection symptoms and their close contacts should wear surgical mask

30. Early Detection • Inform the Hall Management if you suspect that there is clustering of diseases, e.g. • Gastroenteritis • Influenza-like illness • Hand-foot-mouth disease • Acute conjunctivitis

31. Summary • Chain of Propagation of Communicable Diseases • Break the Chain • Good personal, environment and food hygiene • Hand washing and alcohol handrub • Build up immunity by vaccination and healthy lifestyle • Disinfection • Early detection, isolation and treatment of patients

32. References • Infection Control Corner, Centre for Health Protection • http://www.chp.gov.hk/en/guideline_infection/346.html • Hand washing video, fromthe University of Leicester • http://www.youtube.com/watch?v=sjpWwjzCbrw