Transcript Diseases

Disease of Skin and Eyes
Ch 21
Necrotizing fasciitis
• Streptococcus pyogenes
• Causes extensive tissue damage
• Treatment is Surgical removal of tissue,
Penicillin
Invasive Group A Beta
Hemolytic Streptococcal
Infections
• Streptokinases
• Hyaluronidase
• Exotoxin A,
superantigen
• Cellulitis
• Necrotizing
fasciitis
Figure 21.8
Impetigo
• Staphylococcus aureus or Streptococcus
pyogenes
• Superficial skin infection; isolated pustules
• Penicillin for Streptococcus infections
• Methicillin or cephalosporin for
Staphylococcus
Streptococcal Skin Infections
• Erysipelas
• Impetigo
Figure 21.6, 7
Shingles
• Varicella-zoster virus (VZV)
• Vesicles similar to chickenpox; typically on
one side of waist, face and scalp, or upper
chest
– Usualy along dermatome’s. One or 2
– Can cause persistant pain in the affected
nerves postherpetic neuralgia
• Normal immunity is best
• Acyclovir esp for immunocompromised
Boils
• Staphylococcal infection
• A somewhat larger pus-containing lesions within
the dermis.
• May cause abscesses that are accumulations of
pus that may penetrate into deeper tissues and
develop into cellulitis
• Can be treated with penicillins
• May need to be lanced and foreign body
removed.
Acne
• Small inflamed papules and pustules
• Heal spontaneously within a few days.
• When Propionibacterium acnes
(anaerobic) produces fatty acids and
causes an immune response.
• Skin peels reduce the chance of pores
bercomming clogged
• Tetracyclines can reduce the amount of
bacteria
Chicken Pox
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Mild disease in children
VZV herpes only in humans.
Oka live attenuated vaccine
With Aspirin can cause Reye’s syndrome
Develop into shingles as an adult
100 deaths a year
Herpes
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Herpes simplex virus type 1
Large Double stranded DNA virus
Develops latent infection in nerves
Most commonly as cold sores-vesicles
around mouth; can also affect other areas
of skin and mucous membranes
• Fluid in vessels contains virus and is
infectious
• Acyclovir may modify (reduce)symptoms.
Rubella (German measles)
• Rubella virus
• Mild disease with a rash resembling measles,
but less extensive and disappears in 3 days or
less
• No treatment.
• MMR
• Can cause Birth defects and death to
undeveloped fetus
• May want to screen women of childbearing age
for antibodies
Measles (Rubeola)
• Measles virus
• Transmitted by
respiratory route
• Macular rash and Koplik's
spots
• Prevented by
vaccination(MMR) at
15mo
• Encephalitis in 1 in 1000
cases
• Subacute sclerosing
panencephalitis in 1 in
1,000,000 cases
Figure 21.14
Ringworm
• Dermatophytes
• Infect the bodies outermost surface
• Depends on the bodys immune response
– Red, weeping, swelling
• Topical antifungals
– Miconazole
– clotrimazole
Scabies
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Sarcoptes scabiei a mite
Transferred from person to person or by fomites
Common worldwide
Lives on skin, female burrows into the skin to lay
eggs.
• Resembles other itchy skin disease, need to
look for mites or eggs.
• Lasts a long time (7 year itch)
• Arachnicide gamma benzene
Disease of the nervous system
Ch 22
Meningitis
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Neisseria meningitidis
Transferred by respiratory droplets
May live in nose and throat as normal flora
Vaccine does not cover all serotypes
Rapid onset, high fever, stiff nect,
headache worsteing, possible agitated
behavior similar to drug overdose
• Rifampin and Penicillin G
Tetanus
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Clostridium tetani
Normal flora of animals some humans.
Neurotoxin made in bacteria in a wound.
Immunization
Stiff muscles
Botulism
• Clostridium botulinum
• Affects the preipheral nervous system.
• Stops release of acetylcholene, resulting
in flaccid paralysis
• Support of systems untill toxin is
neutralized.
• Antiserum
• Honey a risk in infant botulism
Poliomyelitis
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Enterovirus group: polioviruses
Paralysis only in 1% of infected individuals
Multiplies in throat and intestines.
Viremia results in infection of the motor
cells of CNS. Killing these cells.
• The Sabin oral vaccine is no longer used
in the US because of reversions.
• Inactivated now used.
Rabies
• Family Rhabdoviridae genus Lyssavirus
bullet shaped negative-sense RNA
• Initially nonspecific compatible with
Fluelike illness. (fever, headache and
general malaise 10 days to 6 years after
infection.
• Hydrophobia
• Not treatable after symptoms occur death
in 100%
Rabies 2
• Treatment: post exposure prophylaxis
• Antirabies vaccine and immune globulin
injections.
• Skunk is the primary reservoir in the bay
area.
Trypanosomiasis African Sleeping
sickness
• Trypanosoma brucie gambiense
• Spread by tsetse fly vector
• Early symptoms include reduction of
physical and mental activity, will move into
coma as organism enters CSF.
• Treatment,eflornithine (enzyme blocker)
• Vaccine is being developed, hampered by
antigen variability
mainly avoidance.
Crutzfeldt-jakob disease
• Spongiform encephalophathies
• 200 cases per year in the us, often in
families.
• Prion-contaminated tissue
• Not known.
• May be infected blood or tissue
Transmissible Spongiform
Encephalopathies
Figure 22.17a
Disease of Cardiovascular and
Lymphatic system
Ch 23
Rheumatic fever
• Group a beta hemolytic streptococci
(Streptococcus pyogenes)
• Autoimmune condition; repeated
streptococcal infections result in
antibodies that damage the heart valve
tissue.
• Reason that strep throat is vigorously
treated.
• Still sensitive to Penicillin.
Yellow Fever
• Fiver chills and headache followed by
nausea and vomiting. Followed by
jaundice.
• Mortality rate 20%
• Viral hemorrhagic fever carried by
mosquito
• Monkey are a reservoir but human-human
is mostly how it happens.
• Live attenuated viral vaccine
Anthrax
• Symptoms vary according to portal of
entry
– Cutaneous
– Gastrointestinal
– Inhallational (pulmonary) most deadly
• Mild fever, coughing and some chest pain.
– Mild symptoms not usually responded to
– Progresses to septic shock in 2-3 days
• Antibiotics if administered on time.
Gangrene
Lyme Disease
Tularemia
Relapsing Fever
Infectious mononucleosis
Malaria
• Plasmodium
• A mosquito-borne disease common to hot
climates, characterized by fever and chills
at intervals may be fatal in small children.
• Working on vaccine.
Elephantitis
• Student talk
Schistosomiasis
• Schistosoma spp
• Eggs produced by schistosomes lodge in
tissue and induce damaging inflammation.
Ebola
Disease of the Respiratory System
Ch 24
Strep throat
• Streptococcus pyogenes
• Inflame Mucous membranes of the throat
Pneumonia
Pneumonic Plague
Diphtheria
Pertussis
Tuberculosis
Legionellosis
• Legionella pneumophila
• Potentially fatal pneumonia that tends to
affect older males who drink or smoke
heavily. Pathogen grows in water such as
air-conditioning towers and shower heads.
Influenza
• Influenzavirus many types
• Characterized by chills, fever, headache,
and muscular aches. Virus changes
antigenic character rapidly, so there is
limited immunity following recovery.
• 10-20k Americans die a year.
• Transferred from humans to animals
• Usually from the orient.
Histoplasmosis
• Histoplasma capsulatum
• Fungal pathogen grows in soil, esp if
contaminated with bird droppings.
Widespread in Ohio and Mississippi river
valleys; occasionally fatal.
Colds
• Rhinoviruses, Coronaviruses
• Young average 4 per year.
• Isolate populations develop group
immunity.
• Sneezing excessive nasal secretion.
• Usually not accompanied by fever
• Last about a week. OCD’s do not reduce
this
Diseases of the Digestive system
Ch 25
Food poisoning
• Staphylococcus aureus Exotoxins
• Toxin causes rapid onset of nausea,
vomiting and diarrhea
Salmonellosis
Periodontal disease
Shigellosis
• Shigella may be pathogenic E. coli
• Bacteria are shed in human feces;
ingested, they invade and multiply in
intestinal epithelial cells. Infection spreads
to neighboring cells causing tissue damage
and dysentery.
• Only in primates
• Low death rate
• Not a good vaccine.
• Antibiotics and rehydration
Colitis
Cholera
• student
Hepatitis C
Peptic ulcer disease
• Helicobacter pylori
• Pathogen is adapted to survive in
stomach; presence leads to peptic ulcers
• Mixture of antibiotics.
• Urea breath test. (urease from bacteria)
Mumps
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Mumps virus
Painful swelling of parotid glands
Transmitted by saliva to respiratory tact
MMR (measles, mumps, rubella vaccine)
Is a live attenuated viral disease.
Sterility or other organ systems is rare.
Viral gastroenteritis
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Rotavirus or Norwalk agent
Is a self-limiting infection.
Usually not fatal.
Rehydration is best therapy.
May cause death in 3rd would countries.
Cryptosporidiosis
• Cryptosporidium parvum
• Shed in animal feces, protozoan enters
water supply: causes self-limiting diarrhea
but may be life-threatening if
immunosupressed.
• Diarrhea for 10 -14 days
• Cysts must be removed by filtration
• Oral hydration is the only treatment
tapeworm
• Taenia saginata or T. solium
• Helminth lives off undigested intestinal
contents with few symptoms.
• Usually transmitted by ingesting larvae in
meats. (larvae stage is most damaging)
• 3% of human population
• Niclosamide is drug of choice
Diseases of the urinary and
reproductive systems
Ch 26
Cystitis
• E. coli Staphylococcus saprophyticus
• Difficulty or pain in urination.
• Trimethoprim-sulfamethoxazol other
antibiotics have been show to be
successful.
Gonorrhea
• Neisseria gonorrhoeae
• Males painful urination and discharge of
pus. Females few symptoms but possible
complication such as PID.
• Fairly good infection rate bout 50%
• Ophthalmia neonatorum
PID
• N. gonorrhoeae, Chlamydia trachomatis
• Chronic abdominal pain; possible infertility
if uterine tubes are scarred.
• Combination of doxycycline and
cephalosporins
Genital herpes
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Herpes simplex virus type2
Painful vesicles in genital area
Have recurrences, may taper over time.
Neonatal herpes possible, most damaging
if initial infection occurs during pregnancy.
• Acyclovir may reduce symptoms and
prevent recurrences.
Genital warts
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Papillomavirus
Warts in genital area
Predisposition to cancer.
Usually self resolves
By use various therapies to remove
dermal layer.
trichomoniasis
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Trichomonas vaginalis
Vaginal itching, greenish yellow discharge
Is Protozoan
When pH of the vagina increases
Diagnosed by protozoa in discharge
Oral metronidazol to both partners
Candidiasis
• Fungal Candida albicans
• NGU
• Vulvovaginal has lesions, itching and
irritation.
• Predisposing factors: pregnancy, diabetes,
tumors and antibacterial chemotherapy.
• Diagnosis: observation of fungus and
isolation from lesions
Aids
• student
Food poisining
• http://vm.cfsan.fda.gov/~mow/chap3.html