Diseases/Phenomenons

Diseases/Phenomenons

1. 1.Influnenza

   • 1. it is first mentioned by Hippocrates 2. discovered by Christopher Andrewa, Wilson Smith and Patrick LAidlaw
   • 1. Important example:Avian Flu(Bird Flu)
   • Symptoms
     • 1.Headache 2.Dry cough 3.Fever4..Runny nose
     • 5. Sore throat 6. Fatigue 7. Body aches and Myalgia
   • Transmission
     • a. Respiratory secretions
       • spread through respiratory secretion of infected  persons
     • b. Droplet transmission
       • Generated by sneezing,coughing and talking
     • c. Contact transmission
       • 1.Direct touching an infected person 2.Indirect toughing an object contaiminated by infected human
   • Diagnosis
     • Chemically
       • Laboratory test: 1.isolation of influenza virus from clinical specimen(e.g. sputum,throat) 2. serologic assay for influenza IgG: use Direct Antigen Testing for Type A virus
     • Physically
       • 1.clinical and epidemiological characteristics
   • Pathological mechanism
     • 1.First infects upper respiratory  tract  and then initiates a new infection in the host 2.caused by influenza virus***
   • Influenza Virus
     • Nomenclature: (i) H3N2:  H=Hemagglutinin N-Neuraminidase
     • (ii) Type of nuclear material: e.g. A/Moscow/21/99(H3N2)= Virus type/Geographic origin/strain number/year of isolation(Virus subtype)
     • Categories
       • base on the strains of influenza virus
       • Type A***
         • 1. with the ability to  cause severe diseases (Swine flu: H1N1 ,Bird flu :H5N1)
         • 2.wide host range, highest serotypes 3.all aged 4.can come into pandemic
       • Type B
         • 1. common found in human 2.two serotypes present
         • 3. primarily affect children:milder epidemic due to limited host range
       • Type C
         • 1. rarely reported in human 2. no epidemics
     • Why subtypes?
       • Influenza antigenic changes
         • structure of Hemagglutinin and Neuraminidase periodically change
         • Shift
           • 1.Major change and generate new subtype 2.MOA: exchange of gene segment 3.can cause pandemic
         • Drift
           • 1.Minor change, same subtype 2.MOA: point mutation in gene 3. may cause epidemic
   • General examples
     • 1.Avian flu(H5N1)*** 2. Swine flu(H1N1)
     • Avian influenza
       • 1. known as bird-flu 2.many subtypes:the most highly pathogenis is H5N1
       • comparison
         • 1.Effect-replication in the lower tract and will cause viral pneumonia 2. high mortality rate(60%)

2. 2.Tuberculosis

   • 1. describer since the time of Hippo crates 2.become major cause of death in europe
   • 3. caused by M. tuberculosis
   • 4. classified into: -latent tuberculosis infection -active tuberculosis infection
   • caused by M. Tuberculosis
     • characteristic and pathological feature
   • Transmission
     • 1.Reservoir:human 2. Air borne disease(aerosol transimission)
   • Risk factors
     • a. weakened IS
     • b. Geograpic area
     • c. Poverty and substance abuse
   • Control strategies
     • 1.TB preventive Rx:prevent latent TB to be Active TB or Uninfected/susceptible with Primary TB 2.Treatment of TB/Vacinnation: for active TB and make the patient become uninfected
     • Challenges
       • 1.HIV epidemic 2.Multidrug-resistant TB 3. Poor infrastructure of Health service 4.Lack of support

3. 3.Diarrheal Diseases

   • -The passage of 3 or more loose or liquid stools per day
   • a. Acute water diarrhoea
     • 1.last several hours or days 2.include colera
   • b. Acute bloody diarrhoea
     • also called dysentery
   • c. Persistent diarrhoea
     • last 14 days or longer
   • Causes
     • by transmission
       • Agents
         • 2.Viral
           • 1. Rotavirus 2. Calicivirus 3.Astrovirus
         • 3.Parasitic
           • 1.Giardia lambila 2.Isospora belli 3. Entameba histolytica
         • 1.Bacterial
       • Transmission route***
         • 1.Fecal-oral route(common) -Cholera:water born disease(transmitted through water contaminated with feces)
         • 2.Some viruses(rotavirus) can be transmitted through air 3.Nosocomial transmission 4.Shigellosis(a water-washed disease):mainly transmitted through person-to-person -lack of water can cause more transmission
   • List of risk factors
     • 1.Malnutrition 2.Micronutrient deficiency 3.Gastric acid 4.Genetic factors(person of blood group O have a greater risk for cholera) 5.Immunity 6.Antimicrobial resistant***

4. 4.Viral Hepititis