Unicellular organisms that come in 3 shapes: ROUND (COED) / ROD SHAPED (BACILLI) / SPIRAL ( SPIROCHETES). Examples of bacteria are staphylococcus , Streptococcus , Escherichia coli (normal flora in colon), pseudomonas (blue-green)
unicellular yeasts or multicellular molds, live on dead organic matter. Fungal infections are called mycotic infections. Common fungus is candida albicans
Smallest microorganisms that can only reproduce inside living host cells. All viruses cause disease, although they sometimes remain dormant inside human hosts. Examples are herpes, hepatitis, HIV
Resemble bacteria, but reproduce like viruses. Rickettsial disease are spread to humans by arthropods, which are invertebrate animals with segmented bodies and jointed legs. Examples are ticks and mosquitoes.
unicellular parasites that have the ability to move and usually live in the soil. Examples are plasmodium (causes malaria) Trichomonas (causes vaginal infections)
multicellular animals, not all are microscopic. Include roundworms, tapeworms, and flukes
Chain of infection
This is a sequence of 6 steps that enables the spread of pathogens. If the chain is broken at any point, the pathogen cannot spread and cause disease
6 steps of chain of infection
Causative agent / susceptible host / portal of entry / mode of transfer / portal of exit / reservoir
Physical transfer from an infected person to another person by being with them or touching them
having contact with contaminated objects like linens, dressings, instruments etc..
Stages of infection
INCUBATION PERIOD - interval between the entrance of the pathogen into the body and the appearance of symptoms / PRODROMAL STAGE - Time interval from onset of nonspecific symptoms to more specific ones. May have fatigue, achiness (pain) / ACUTE STAGE - symptoms become severe and specific to the infection / CONVALESCENT STAGE - symptoms subside / RESOLUTION - pathogen is destroyed, health is restored
Elderly and the very young
Who is at most risk for infection?
Diagnose an infection
Complete blood count (CBC) - WBC count is usually elevated with an infection. Count should be 5k - 10k. / GRAM STAIN - staining a bacterial slide in order to show whether the organism is a gram negative or gram positive. / CULTURE & SENSITIVITY ( C&S) - a culture is used to identify the causative bacteria and the sensitivity study is done to determine the best antibiotic.
What are PPE ?
Personal Protective Equipment (head cover, mask, eyewear, isolation gown, shoe covers, gloves)
Measles, chickenpox, TB
What type of organisms would be classified as needing airborne precautions:
Wound infections / draining abscess / GI infections causing diarrhea, viral conjunctivitis/ respiratory and skin infections / multidrug resistant organisms
What type of organisms would be classified as needing contact precautions:
Biologic defense mechanisms:
barriers to pathogens normally present in humans / REFLEX'S- blinking, sneezing, coughing / WBC's attack pathogens and their activity is increased by fever / Mechanical defenses - Intact skin and mucous membranes serve as the first line of defense.