Infectious Disorders

Infectious Disorders
Presentation from: Chipola College

Stages of infectious disease
* Incubation period
o Time between the invasion of an organism & the onset of S/S
o 7-10 days (maybe longer depending upon pathogen)
* Prodromal period
o Time between the beginning of nonspecific symptoms & specific symptoms
o Hours to a few days
* Illness
o Specific symptoms are evident
* Convalescent period
o Time between when the S/S begin to fade and a return to full wellness

Chain of infection
* Reservoir
o Place in which organisms grow & reproduce
* Portal of exit
o Method by which organisms leave an infected person’s body to be spread to another individual
o Table 43-1 (blood, respiratory secretions, feces, & exudate from lesions)
* Means of transmission
o Direct contact, indirect contact, fomites (inanimate objects, ex. food, bedding, towels, combs, drinking glasses, etc), insects, or vermin
* Portal of entry
o Means by which a pathogen can enter an individual’s body
o Inhalation, ingestions, breaks in the skin (ex. bites, abrasions, burns)
* Susceptible host

VIRAL INFECTIONS
* Viral exanthems (rashes)
o Exanthem subitum (Roseola Infantum)
+ Rash following a high fever
o Rubella (German measles)
+ Rarely seen because of MMR
+ Important because it can cause serious birth defects
o Measles (Rubeola)
+ Rarely seen because of MMR
+ Occurs with Coryza (rhinitis and sore throat), cough, and conjunctiva
+ Koplik’s spots-whitish spots on the buccal membranes
* Viral exanthems (rashes)
o Chickenpox (Varicella zoster)
+ Will become rare because of mandatory immunization
+ Fluid filled vesicles that crust over, occur in different stages
+ Highly contagious, spread by respiratory droplets as well as contact
o Herpes zoster
+ Same virus as chicken pox but usually occurs in older children/adults
+ Causes painful vesicles along a dermatome
+ May be treated with acyclovir
o Erythema infectiosum (Fifth disease)
+ “slapped cheeks” appearance and a lacy rash
+ Important because it can cause birth defects
o Smallpox (Variola)
+ Important because of bioterrorism
+ People with this are really sick with fever, chills, vomiting, then rash
+ Rash progresses from macule to papule to vesicle to pustule.

VIRAL INFECTIONS
* Enteroviruses
o Coxsackievirus infections
+ Herpangina
o Poliovirus infections: Poliomyelitis
+ Occurs in other parts of the world
+ IPV used now instead of OPV because of immunocompromised people contracting disease shed in stool

Cytomegalovirus

* Common cause of congenital infection in infants
* Some children are asymptomatic for years and then manifest with
o Mental retardation/learning disabilities
o Hearing loss/blindness
* Symptoms evident at birth can include
o Jaundice
o Seizures
o Respiratory distress
o microcephaly
* Therapy is experimental
* Viruses causing central nervous system diseases
o Rabies
* Other viral infections
o Mumps
+ Rarely seen because of MMR
+ Mumps in a teenage or adult man can lead to sterility
o Infectious mononucleosis
+ S/S similar to tonsillitis with sore throat, lymphadenopathy, and fever
+ Spleen is enlarged and fatigue can last ~6 weeks
+ Treat symptoms only

OTHER INFECTIONS
* Scarlet fever
o Group A beta-hemolytic strept
o Often seen with Strept throat
o Usually not seen with “cold” symptoms
o Treated for 10-14 days with antibiotics
* Eye infections/inflammations
o Conjunctivitis (viral or bacterial)
+ Starts in one eye and moves to the other
+ Bacterial…purulent discharge
+ Viral…watery discharge
+ Schools or day care will only believe it is bacterial so treat with antibiotic ointment
+ Highly contagious, can be spread by gnats

OTHER BACTERIAL INFECTIONS

* Anthrax
o Important because of bioterrorism
o Three types, inhalation, cutaneous, & gastro
o Inhalation
+ Most serious, >90% mortality
+ Begins with flu like symptoms
o Cutaneous
+ Begins as a papule and progresses to a painless depressed black eschar
+ Mortality 1% with antibiotic therapy
o Gastrointestinal
+ Acquired by eating undercooked meat infected with anthrax
+ Develops abd. pain, diarrhea; mortality is 25%
o Management
+ Cipro for >18 years, Doxycycline for <18.

* Diphtheria
o S/S
+ Foul nasal discharge, low-grade fever
+ Gray membranes on tonsils and pharynx
+ Neck edema
o Therapeutic management
+ DTaP…rarely seen due to immunization
* Pertussis
o S/S
+ See Box 40-1 pg. 1034
o Therapeutic management
+ DTaP…rarely seen due to immunization
* Lyme disease
o Transmitted by the deer tick
o S/S
+ Papule at the site of the tick progressing to a large swollen ring
+ Systemic involvement
o Therapeutic Management
+ Amoxicillin or PCN V or doxycycline
+ Prevention is the most important tool
* Rickettsial diseases
o Rocky mountain spotted fever
+ Transmitted by the wood, dog, or rabbit tick
+ S/S
# A reddened area develops at the site of the tick bite
# Afterwards, rash, headache, fever, and mental confusion
# CNS involvement
+ Management
# Tetracycline for 7-10 days
# Prevention

OTHER INFECTIOUS PATHOGENS

* Helminthic infections
o Roundworms (Ascariasis)
o Hookworms
o Pinworms

Infectious Disorders.ppt