CPHM111: COMMUNICABLE DISEASES

• Communicable diseases are often the leading causes of all illness in the country today
• Bacteria: the most common infection-causing microorganisms
• Viruses: consist primarily of nucleic acid and therefore must enter a living cells in order to reproduce
• Fungi: includes yeast and molds
• Parasites: Live on other living microorganism
• Etiologic agent: ability of the microorganisms to enter the body, the susceptibility of the host, and the ability of microorganisms to live in the host’s body
• Pathogenicity: any microorganisms is capable of producing an infectious process depends on the number of microorganism
• Reservoir: source of microorganisms, people are the most common source of infection
• Portal of exit from the reservoir: Before an infection can establish itself in a host, the microorganism must leave the reservoir.
• Direct Transmission: immediate and direct transfer of microorganisms from person to person through touching, biting, kissing, or sexual intercourse. Droplet spread is also a form of direct transmission but can occur only of the source and the host are within 3 feet of each other.
• Vehicle borne transmission: any substance that serves as an intermediate means to transport and introducing infectious agent into susceptible host through a suitable portal of entry
• Fomites: inanimate objects or materials
• Vector borne transmission: animal or flying or crawling insects that serves as an intermediate means of transporting the infectious agents
• Portal of entry to the susceptible host: Before a person can became infected, microorganisms must enter the body, microorganisms enter the body of the host by the same route they used to leave the source
• Susceptible host: any person who is at risk for infection. A compromised host is a person “at increased risk:, an individual who for one or more reasons is more likely than others to acquire an infection.
• Disease cycle maybe broken down by these factors:

  1. Increasing host resistance
  2. Destruction of the source and the reservoir
  3. Destruction of the agent in the environment
  4. Avoidance of exposure
• Handwashing: most important procedure for preventing the transfer of microorganisms and the therefore nosocomial infection is correct and frequent handwashing
• Immunization: process of introducing vaccine into the body to produce antibodies that will protect our body against a specific infectious agen
• Vaccine available for routine immunization

  1. DPT (Diphtheria, pertussis and tetanus)
  2. OPV (Oral Polio Vaccine)
  3. MMR (Measles, Mumps, Rubella) vaccine
  4. Hib (H.influenza type B) polysaccharide vaccine
  5. Hepatitis B vaccine
  6. BCG (Bacillus of Calmette and Guerin)
  7. CDT (Cholera, Dysentery, Typhoid)
• Diphtheria: caused by Corynebacterium diphtheriae
• Pertussis: caused by Bordetella pertussis
• Tetanus: caused by Clostridium tetani
• German measles: caused by Polio virus
• Measles: caused by Measles virus
• Mumps: caused by Mumps virus
• German measles: caused by Rubella virus
• Meningitis: caused by Haemophilus influenza
• Tuberculosis: caused by Mycobacterium tuberculosis
• Cholera: caused by Vibrio cholera
• Dysentery: caused by shigella dysenteriae
• Typhoid: caused by salmonella typhii
• Chemoprophylaxis: Administration of drugs to prevent occurrence of infection

  e.g. Penicillin for gonorrhea, Chloroquine for malaria, INH for tuberculosis
• Mechanical Prophylaxis: mechanical barriers between the sources of agent and host such as use of mosquito nets, masks or gloves
• INFLUENZA: Highly communicable disease characterized by abrupt onset with fever which last 1 to 6 days, chilly sensation or chills, aches or pain in the back and limbs with prostrations. Respiratory symptoms include coryza, sore throat and cough.
• PNEUMONIAS: acute infectious disease of the lungs usually caused by the pneumococcus resulting in the consolidation of one or more lobes of either one or both lungs.
• Causative Agent of Pneumonia:

  • Streptococcus pneumonia (Diplococcus pneumonia)
  • Occasionally Klebsiella pneumonia
• CHOLERA (El Tor): acute serious illness characterized by sudden onset of acute and profuse colorless diarrhea, vomiting, severe dehydration, muscular cramps, cyanosis and in severe cases collapse.
• Causative Agent of Cholera El Tor: Vibrio cholera
• TUBERCULOSIS: highly contagious bacterial infection, usually affecting the lungs but can also affect other organs of the body like brain, kidney, intestine, and bones


  TB ranks 6th in the leading cause of morbidity (2004) and in the Philippines is 243/100000 population (2006)
• Treatment for Tuberculosis: (per day intensive phase 2 mons)

  • Isoniazid (1)
  • Rifampicin (1)
  • Pyrazinamide (2)
  • Ethambutol (2)