Nurs200

• Person-to-person (fecal, oral)
• Physical contact between source and susceptible host (e.g., touching client feces and then touching your inner mouth or consuming contaminated food)
• Example: Hepatitis A virus, Shigella, Staphylococcus

• Personal contact of susceptible host with contaminated inanimate object (e.g., needles or sharp objects, dressings, environment)
• Example:Hepatitis B virus, hepatitis C virus, human immunodeficiency virus (HIV), Staphylococcus, respiratory syncytial virus (RSV), Pseudomonas, methicillin-resistant Staphylococcus aureus (MRSA)

• Large particles that travel up to 3 feet and come in contact with susceptible host (e.g., coughing, sneezing, or talking)
• Example:Influenza virus, rubella virus, bacterial meningitis

• Droplet nuclei, or residue or evaporated droplets suspended in air (e.g., coughing, sneezing) or carried on dust particles
• Example: Mycobacterium tuberculosis (tuberculosis), varicella zoster virus (chickenpox), Aspergillus, measles virus

• Contaminated items -Vibrio cholerae, MRSA
• Water-Pseudomonas, Legionella
• Drugs, solutions - Pseudomonas
• Blood- Hepatitis B virus, hepatitis C virus, HIV, syphilis
• Food -(improperly handled, stored, or cooked; fresh or thawed meats) Salmonella, Escherichia coli, Clostridium botulinum

• External mechanical transfer (flies) - V. cholerae
• Internal transmission such as parasitic conditions between vector and host, such as:
• Mosquito - Plasmodium falciparum (malaria), West Nile virus
• Louse- Rickettsia typhi
• Flea - Yersinia pestis (plague)
• Tick - Borrelia burgdorferi (Lyme disease)

• depends on the individual degree of resistance to a pathogen (immune response).
• Some of the factors that influence a person's susceptibility (resistance) include age, nutritional status, presence of chronic disease, trauma, and smoking.
• *Organisms with resistance to key antibiotics are becoming more common in all health care settings, but especially acute care. This is associated with the frequent and sometimes inappropriate use of antibiotics over the years in all settings (i.e., acute care, ambulatory care, clinics, and long-term care).

dose of the organism, and the susceptibility of the host.

(e.g., a wound infection), the client usually experiences localized symptoms, such as pain and tenderness and redness at the wound site.

• An infection that affects the entire body instead of just a single organ or part
• *can become fatal if undetected and untreated.

Interval between entrance of pathogen into body and appearance of first symptoms (e.g., chickenpox, 10 to 21 days post exposure; common cold, 1 to 2 days; influenza, 1 to 5 days; mumps, 12 to 26 days).

Interval from onset of nonspecific signs and symptoms (malaise, low-grade fever, fatigue) to more specific symptoms. (During this time, microorganisms grow and multiply, and client may be capable of spreading disease to others.) For example, herpes simplex begins with itching and tingling at the site before the lesion appears.

Interval when client manifests signs and symptoms specific to type of infection. (For example, strep throat is manifested by sore throat, pain, and swelling; mumps is manifested by high fever, parotid and salivary gland swelling.)

Interval when acute symptoms of infection disappear. (Length of recovery depends on severity of infection and client's host resistance; recovery may take several days to months.)

a protective reaction that serves to neutralize pathogens and repair body cells. Normal flora, body system defenses, and inflammation are all nonspecific defenses that protect against microorganisms regardless of prior exposure.

the treatment of infection can lead to suprainfection.

develops when broad-spectrum antibiotics eliminate a wide range of normal flora organisms, not just those causing infection. When normal bacterial flora are eliminated, the body's defenses are reduced, which allows for disease-producing microorganisms to multiply, causing illness.

an immediate response to cellular injury. When this occurs, rapid vasodilatation occurs, which allows more blood near the location of the injury. The increase in local blood flow causes the redness at the site of inflammation. The localized warmth at the site is also the result of a greater volume of blood.

¢Age

¢Heredity

¢Cultural Practices

¢Nutritional Status

¢Stress

¢Rest & Exercise

¢Inadequate Defenses

¢Personal Habits

¢Environmental Factors

• ¢Immunization/Disease
• History

¢Medical Therapies

¢Clinical Presentation

first inspect the area for redness and swelling caused by inflammation. Because there may be drainage from open lesions or wounds, wear clean gloves. Infected drainage may be yellow, green, or brown, depending on the pathogen. For example, green nasal secretions may indicate a sinus infection. Ask the client about pain or tenderness around the site. Some clients may complain of tightness and pain caused by edema. If the infected area is large enough, movement may be restricted. Gentle palpation of an infected area usually results in some degree of tenderness. In addition to gloves, wear a surgical mask to prevent additional contamination of the wound. Wear protective eyewear when there is a risk for splash or spray with blood or body fluids.

• They usually result in fever, fatigue, nausea/vomiting, and malaise. Lymph nodes that drain the area of infection often become enlarged, swollen, and tender during palpation. For example, an abscess in the peritoneal cavity may cause enlargement of lymph nodes in the groin. An infection of the upper respiratorytract may cause cervical lymph node enlargement. If an infection is serious and widespread, all major lymph nodes may enlarge.
• *can develop after treatment for localized infection has failed
• *an elevation in body temperature can lead to episodes of increased heart and respiratory rates and low blood pressure
• *a pulmonary infection may result in a productive cough with purulent sputum. A urinary tract infection may result in cloudy, foul-smelling urine.

• 55%-70%
• Increased in acute suppurative (pus-forming) infection, decreased in overwhelming bacterial infection (older adult)

• 20%-40%
• Increased in chronic bacterial and viral infection, decreased in sepsis

• 5%-10%
• Increased in protozoan, rickettsial, and tuberculosis infections

• 1%-4%
• Increased in parasitic infection

• 0.5%-1.5%
• Normal during infection