Respiratory Infection

1. Respiratory Infection المرحلة الرابعة اعداد د. وفاء محمود جاسم

2. Main Subjects 1- What is respiratory infection 2- What are the main causes of respiratory infection 3- Main characteristic features of respiratory disease 4- Mode of transmission 5- Examples of respiratory diseases

3. Acute respiratory infection is an infection that may interfere with normal breathing. It usually begins as a viral infection in the nose, trachea or lungs. • Acute respiratory infections are infectious. This means they can spread from one person to another. • The disease is quite widespread. It’s particularly dangerous for children, older adults, and people with immune system disorders.

4. Causes for Respiratory Infection 1- Adenoviruses Adenoviruses are a class of microorganisms that can cause acute respiratory infection. Adenoviruses consist of more than 50 different types of viruses known to cause the common cold, bronchitis, and pneumonia. 2- Pneumococcus Pneumococcus is a type of bacterium that causes meningitis. 3- Rhinoviruses

5. Infective agent

6. Characteristic features • Reservoir: mostly human, some have animal reservoir like rodents in Plague. • Carrier: play important role in epidemiology, like meningococcal infections. • Host: • Non-specific defense: • mucous membrane /mechanical action (trap & excretion through ciliated epithelium. • Reflexes: coughing & sneezing • Lysozyme in mucous secretion act as antimicrobial • Immunization: Acquired (past infection) & Artificial (vaccine)

7. Mode of transmission They are all Air-born infections but have three mechanisms for transmission: • Droplets: heavy, settle rapidly so transmit to short distance & not inhaled to lower RT • Droplets nuclei = droplet evaporated before settlement, rapidly detached, small enough to pass to bronchioles & alveoli (LRT) • Dust: M.O. from sputum or droplet settle on dust & when inhaled transmit infection (dust-born infection)

8. Prevention and control • Infective agent: • Elimination of human & animal reservoirs • Disinfection of floors & elimination of dust • Mode of transmission: • Air hygiene: good ventilation, • Avoid overcrowding • Personal hygiene: avoid coughing, sneezing, spitting or talking directly to the face of others, wearing face mask • Host: • Specific immunization: active & passive • Chemoprophylaxis, e.g. isonizid in TB

9. Chicken pox(Varicella Acute generalized viral disease characterized by : 1- Sudden onset of fever, and skin rash . 2- Maculo- papular rash ---- few hours vesicles--- 3-4 days – granular crusts . 3- Lesion commonly occur in successive groups with several stages of maturity present at the same time . 4- More abundant on covered area than exposed parts of the body .

10. 5- Lesion may appear high in the axilla and on the scalp , M.M of the mouth and conjunctiva . Infectious agent : Human (alpha) herpes virus 3 Reservoir: Human Mode of transmission : 1- Direct contact person to person through droplets or air born spread 2- In direct through solid articles Period of communicability : 1-2 before rash and 5 days after The virus can remain latent in the body for years & cause Herpes Zoster.

11. I.P.: 10-21 days Prevention 1- Vaccination (Live attenuated ) 0.5 ml Sc for children 12m- 12 yrs 2- protection people with high risk fro exposure 3- VZIG is effective when given within 96 hours of exposure Control : 1- isolation – exclude children from school for 5 days after appearance of rash 2- treatment with Acyclovir & Viradabine are effective in the treatment of zoster & immunocompromised patients

14. Small pox Smallpox is a very serious illness caused by variolavirus. Smallpox gets its name from the pus-filled blisters (or pocks) that form during the illness. Mode of transmission Smallpox is contagious. That means the virus can spread to others. It spreads through tiny drops of an infected person's saliva (spit) when the person coughs, talks, or sneezes. Smallpox usually passes from person to person during close, face-to-face contact.

15. Acute systemic viral disease characterized by : 1- sudden onset of fever , malaise , sever backache , with abdominal pain . 2- Fever began to fall , deep seated rash Macules– papules--- vesicles---pustules— Crusted scrabs which fell after 3-4 weeks 3- appeared on the successive stages of maturity . 4- abundant on the exposed part of the body (centrifugal distribution )

16. Types of small pox 1- Variola minor (alostrium ) CFR<1% 2- Variola major (ordinary ) CFR12-40% Infectious agent :Variola virus of orthropox virus Reservoir : Human I.P 7-19 days Period of communicability : first day of the development of the earliest lesion to the disappearance of all scabs The virus can remain latent in the body for years & cause Herpes Zoster. Method of control by immunization with vaccinia virus vaccine

17. Mumpsالنكاف Mumps, also known as epidemic parotitis, is a viral disease caused by the mumps virus which is a member of paramyxoviradae   Initial signs and symptoms often include fever, muscle pain, headache, and feeling tired This is then usually followed by painful swelling of one or both parotid glands

18. Complications 1- Orchitis – unilateral 20-30 % 2- Mastitis 3- Sterility 4- Sensoneural hearing loss 5- Encephalitis 6- Pancratitis 7- Infection during first trimester – spontaneous abortion

19. reservoir: only human Infective material : saliva and respiratory secretions • Period of infectivity: before onset of illness after 6-7 days parotitis 9 days 2 days before maximum infectiousness 4 days after • An infection provides life long immunity. after clinical or in apparent infection • Host factors: Mumps is a disease of children and young adults especially in winter and spring . • Mode of spread: droplet & contact • I.P.: 2-4 weeks

20. Prevention and control 1- Public education 2- Vaccination –MMR – after 12 months 3- Isolation – for 9 days from onset of swelling 4- Avoid close contact 5- Strict hygienic measures