Module 12: Infectious Diseases Flashcards
Sexually transmitted disease are caused by:
- bacteria
- viruses
- protists
- fungi
Pathogens of sexually transmitted diseases are generally only found in body fluids from the ______________ that are exchanged during sexual activity.
genitourinary tract
Rates of a disease are
the number/100,000.
What is the causative organism and recommended treatment of Gonorrhea?
- Neisseria gonorrhoeae
- ceftriaxone + azithromycin
What is the causative organism and recommended treatment of Syphilis?
- Treponema pallidum
- Benzathine penicillin
What is the causative organism and recommended treatment of Chlamydia?
- Chlamydia trachomatis
- tetracycline or azithromycin
This disease is another manifestation of infection with Chlamydia trachomatis.
Lymphogranuloma venereum
What seven groups are at a higher risk for STIs?
- men who have sex with men
- injection drug users
- sex trade workers and their clients/partners
- partners of those with a known case of syphilis, gonorrhea, chlamydia, etc.
- people diagnosed with another STI
- people who have sexual contact in or with partners from endemic areas
- people with multiple partners
____________ is an intracellular pathogen that is the #1 STI in the world
Chlamydia
Neisseria gonorrhoeae in females is characterized by ____________. If left untreated it can lead to __________ , ___________ & ____________.
May also have: ________ & ________ infections.
- Neisseria gonorrhoeae* in females is characterized by mild vaginitis. If left untreated it can lead to pelvic inflammatory disease, infertility and eptopic pregnancy.
- pharyngeal and rectal infections
Neisseria gonorrhoeae symptoms in males inclue:
- urethral discharge
- painful infection of the urethral canal
- pharyngeal and rectal infections
Diagnosis of N. gonorrhoeae via:
- microscopy in symptomatic men with urethral discharge
- culture – growth on Thayer Martin medium
- nucleic amplification tests – via urine specimen
True or False. T. pallidum can be transmitted from an infected woman to the fetus during pregnancy.
True (congenital syphilis)
Having _______ can increase chances of acquiring an HIV infection by 3-5x.
syphilis
What are the three stages of syphilis?
- primary
- secondary
- tertiary
Rates of syphilis are _______; rates of gonorrhea are _________.
rising; rising
Symptoms of untreated syphilis in each of the three stages:
- primary - chancre appears from weeks to a couple months after infection
- secondary - rash, fever, swollen glands, hair loss
- tertiary - benign gummatous, cardio-vascular and late-neuro syphilis.
Diagnosis of T. pallidum (syphilis)
- blood test - serology (agglutination, EIAs, etc)
- tests that look for anti-treponemol antibodies as well as non-treponemal antibodies
- point of care tests
Chlamydia trachomatis causes these three diseases:
- Chlamydia trachomatis infections
- Nongonococcal urethritis
- Lymphogranuloma venereum
This disease has a unique and complex biphasic life cycle; it is only infectious during one life stage.
Chlamydia
The elementary body form of Chlamydia is adapted for ___________ survival, while the reticulate body form is involved in __________ growth and replication.
extracellular, intracellular
A group of closely related microorganisms distinguished by a characteristic set of antigens.
Serovars
Life cycle of Chlamydia
- elementary body attacks host cell
- phagocytosis of elementary body
- conversion to reticulate body
- multiplication of reticulate bodies
- conversion to elementary bodies
- release of elementary bodies
The following are symptoms of what disease:
- infection and inflammation of the reproductive tract, urethritis, proctitis and epididymitis in men
- urethritis, endometritis, and cervicitis in women that can lead to cervical cancer
Chlamydia
This infection can be passed to newborns during childbirth resulting in conjunctivitis or pneumonia.
Chlamydia
Diagnosis of Chlamydia trachomatis is done via:
- nucleic acid amplification tests (NAATs)
- some POC tests
This virus infects epithelial cells around the mouth and lips causing cold sores.
Herpes simplex 1 virus (HSV-1)
Guanin analogue acyclovir drugs are successful in controlling the infectious blister stage and inhibit replication of this virus.
Herpes simplex 2 virus (HSV-2)
Diagnosis of primary genital herpes:
- usually clinical
- lab tests may include staining, direct immunofluorescence or EIA testing
This disease is caused by the protist.
Trichomonas vaginalis
This disease is generally transmitted by sexual contact but may also be transmitted by contaminated toilet seats, paper towel, etc.
Trichomoniasis
This disease is typically asymptomatic in males; in females it is characterized by vaginal discharge, vaginitis, and painful urination.
Trichomoiasis
Diagnosis of trichomoniasis occurs via:
- direct microscopic observation
- cell culture
- immunological techniques
- PCR assay
Metronidazole is the treatment for this disease, with cure rates of 85-95%.
Trichomoniasis
This small icosahedral non-enveloped DS DNA virus has over 100 types.
Human Papillomavirus (HPV)
More than ____ % of sexually active Canadian men and women will have a sexually transmitted HPV infection at some point.
70%
This disease can cause anal and genital warts; and more serious consequences like cervical, penile and anal cancers.
Human Papillomavirus (HPV)
What are the two HPV vaccines available in Canada and how many types of HPV does each immunize against?
- Cervarix (2 types)
- Gardasil (9 types)
What is the causative agent of Acquired Immunodeficiency Syndrome (AIDS)?
Human Immunodeficiency Virus (HIV)
Since the beginning of the epidemic, __________ people have become infected with HIV and ________ people have died from AIDS-related illnesses.
- 80 million
- 35 million
HIV rates in Canada are _______ in men. Female rates are slowly ________.
- higher
- increasing
HIV-1 is _______ virulent than HIV-2.
more
__________ infections are common in AIDS patients.
opportunistic
The most common opportunistic infection in AIDS patients is:
pneumonia
A frequent non-microbial disease in AIDS patients is _________.
Kaposi’s sarcoma
An atypical cancer caused by co-infection of HIV and herpesvirus 8 (HHV-8).
Kaposi’s sarcoma
Retrovirus is an ____________ virus, with two copies of _________ genome that uses the enzyme ___________ to transfer info from RNA to DNA.
- enveloped
- ssRNA
- reverse transcriptase
This virus can integrate into DNA of cells and remain there as a latent virus.
retrovirus
HIV infects cells that containt the _____ cell surface protein, most commonly infecting _______ and _______ cells.
- CD4
- macrophages
- T-helper
HIV _____ and ____ binds CD4 receptor and CCR5 receptor.
- gp120
- gp41
Once inside the host cell, HIV replicates. An altered form of _____ that recognizes ____ on Th1 cells is made so that when the viruses are released from the cells they can go on to infect T-helper cells.
- gp120
- CXCR4
HIV infection results in a progressive decline in CD4 cells, ________ production falls, leading to a reduction of the immune response.
cytokine
In HIV diagnosis, ______ testing predominates.
serological
These drug classes delay the symptoms of AIDS and prolong the life of those infected with HIV.
- nucleoside reverse transcriptase inhibitors
- non-nucleoside reverse transcriptase inhibitors
- protease inhibitors
- fusion inhibitors
- integrase inhibitors
__________ is used, mostly in developed countries as HIV treatment. (3 drugs taken simultaneously)
Highly Active Antiretroviral Therapy (HAART)
___________ infections kill ~ 4 million people per year.
Respiratory
List 5 pathogens that cause upper respiratory infections.
- staphylcoccus aureus
- neisseria menigitidis
- streptococcus pyrogenes
- corynebacterium diptheriae
- haemphilus influenzae
List six pathogens that cause lower respiratory infections.
- influenza virus
- coccidioides immitis
- bordetella pertusis
- streptococcus pneumoniae
- coxiella burnetii
- chlamydophila psittaci
What determines where pathogen particles come to rest in the respiratory tract?
size and speed
Streptococcus classified based on hemolytic properites: __________ oxidase iron in hemoglobin in RBCs; __________ complete rupture of RBCs.
- alpha-hemolytic
- beta-hemolytic
Only encapsulated strains of this pathogen are pathogenic.
Streptococcus pneumoniae
The virulence factor of Streptococcus pneumoniae is its:
capsule
An invasive lung infection that generates a strong inflammatory response.
pneumonia
Treatment for Streptococcus pneumoniae
penicillin
This Gram+ firmicute grows in chains, causes beta-hemolysis, and is further classified based on carbohydrate on cell wall (Lancefield type).
Streptococcus pyogenes (Group A Strep)
This pathogen is the causative agent of: strep throat, middle ear infections, impetego, erysipelas, cellulitis, necrotizing fasciitis, pneumonia and toxic shock.
Streptococcus pyrogenes
Group A Strep may carry a ______________ that encodes streptococcal pyrogenic __________.
- lysogenic bacteriphage
- exotoxins
Streptococcal pyrogenic exotoxins of GAS are responsible for symptoms of _________ and ________.
toxic shock syndrome and scarlet fever
Diagnosis of Streptococcal diseases by:
- culture on blood agar followed by serology for Lancefield type
- antigen detection (rapid tests)
A severe respiratory disease in children that forms irregular shaped rods during growth.
Diptheria
Pathogenic strains of Corynebacterium diptheriae lysogenized by _________ produce a powerful ________ .
bacteriophage beta; exotoxin
___________ toxin inhibits protein synthesis.
Diphtheria
Diphtheria toxin causes:
- tissue death
- appearance of pseudomembrane in the patient’s throat
Corynebacterium diphtheriae is isolated from the throat and grown on Blood agar with ______.
tellurite (loeffler’s medium)
Treatment includes antibiotics: penicillin, erythromycin, gentamicin
Diphtheria
Acute, highly infectious respiratory disease caused by Bordetella pertussis.
Whooping Cough (pertussis)
Bordetella pertussis produces pertussis exotoxin (AB toxin) after attaching to cells up upper respiratory tract, this then:
- induces cAMP
- produces endotoxin
Increases in pertussis activity due to:
- waning immunity
- reduced natural immune boosting
- higher rates of detection
- genetic changes in the bacteria
- clustering of unvaccinated individuals
Diagnosis of Pertussis
- fluorescent antibody staining of nasopharyngeal swab specimen
- culture of the organism
Antibiotic treatment of this pathogen includes ampicillin, tetracycline or erythromycin.
Pertussis
All mycobacterium are _________ due to the waxy mycolic acid content of their cell wall.
acid fast
Tuberculosis is caused by
Mycobacterium tuberculosis
Hansen’s disease (leprosy) is caused by
Mycobacterium leprae
Cell-mediated immunity plays a critical role in the prevention of active disease after infection of this disease.
Tuberculosis
This infection is classified as a primary infection or post-primary infection.
Tuberculosis
In tuberculosis, the primary infection ___________ the patient to the bacteria and alters the individuals response to ______________.
hypersensitizes; subsequent exposures
A diagnostic skin test that measures hypersensitivity.
tuberculin test
Reinfection from bacteria dormant in the lung.
Post-primary tuberculosis infection
Chronic tuberculosis often results in a gradual spread of ____________ in the lungs.
tubercular lesions
What are tubercular lesions?
aggregates of activated macrophages
A common complication of those with HIV infections.
tuberculosis
Treatment of this disease involves antimicrobial therapy with isoniazid and other antibiotics – usually requires a 9 month regimen.
tuberculosis
Antibiotics for tuberculosis treatment cause the bacteria to lose its acid fast properties by:
affecting the synthesis of mycolic acid in mycobacteria
This pathogen causing this disease grows in schwann cells that insulate nerves.
Leprosy
The armadillo is the only experimental animal successfully used to grow this organism.
Mycobacterium leprae
Transmission of this disease by both direct contact and respiratory routes. Has an incubation period that ranges from several weeks to years.
Leprosy
Leprosy is treated with:
antibiotics
Inflammation of the meninges, membranes that line the central nervous system, especially the spinal cord and brain.
Meningitis
Gram-negative, nonsporulating, obligately aerobic, oxidase-positive, encapsulated diplococcus.
Neisseria menengitides
Diagnosis of Meningitis via
Thayer Martin medium
A condition characterized by intravascular coagulation and tissue destruction, shock and death in over 10 percent of cases.
meningococcemia
13 pathogenic strains of Neisseria meningitides are recognized based on differences in their ______________.
capsular polysaccharides
The most prevalent human infections are _______.
viruses
Measles is cause by
paramyxovirus
This is one of the most contagious diseases there is – requires 95% of the population to be immunized in order to reach herd immunity.
Measles
A single-stranded, minus-sense RNA virus that enters the nose and throat by airborne transmission.
paramyxovirus
Caused by a positive-strand RNA virus of the togavirus group.
Rubella (German measles)
Mumps is caused by
paramyxovirus
Characterized by inflammation of the salivary glands.
Mumps
An attenuated combined vaccine covers these three disease:
measles, mumps, rubella (MMR vaccine)
A herpesvirus which is highly contagious and transmitted by infectious droplets.
varicella-zoster virus (VZV)
Varicella-zoster virus causes this childhood disease.
Chickenpox
The varicella zoster virus occasionally migrates to the skin surface, causing a painful skin eruption called
Shingles
Varicella-zoster virus can be immunized against with _________ or ________.
attenuated virus or recombinant vaccine
The most common infectious diseases.
Colds
Colds are viral infections transmitted via
airborne droplets
Colds are commonly caused by
rhinoviruses
Positive-sense, single-stranded RNA viruses with nearly 150 different strains identified.
rhinoviruses
Approximately ¼ of all colds are due to infections with other viruses: _________ and ________.
adenoviruses and coronaviruses
_________ viruses contain a single-stranded, negative-sense, segmented RNA genome surrounded by an envelope composed of protein, a lipid bilayer, and external glycoproteins.
Influenza
Each strain of influenza A virus can be identified by a unique set of surface glycoproteins: __________ and _________.
hemagglutinin (HA)
neuraminidase (NA)
Each influenza A virus has one type of HA and one type of NA on its __________ and is named for the antigens it contains.
viral capsid
The HA antigen is important in:
attaching the influenza virus to host cells
The NA antigen is instrumental in:
releasing the virus from host cells
Influenza outbreaks occur annually because of the
plasticity of the influenza genome
__________ of the genes of the influenza virus is facilitated by the fact that the genome is ________
reassortment; segmented
Minor change in influenza virus antigens due to gene mutation.
Antigenic drift
Major change in influenza virus antigen due to gene reassortment
Antigenic Shift
Gram-negative, spiral-shaped bacterium associated with ulcers, gastritis and gastric cancer.
Helicobacter pylori
Colonizes the non-acid-secreting mucosa of the stomach and upper intestinal tract.
Helicobacter pylori
Helicobacter pylori is diagnosed via ____ and treatable with _______.
PCR; antibiotics
Ebola hemorrhagic fever is caused by _______, a negative strand RNA virus.
filovirus
Case fatality of this disease ranges from 35-75%.
Ebola
Arthropod-transmitted bacterial disease
Lyme disease
Caused by the spirochete Borrelia burgdorferi
Lyme disease
One of only a handful of Bacteria that contain a _______ chromosome.
linear
Lyme disease is spread primarily by the ______.
deer tick
Neurological disease in chronic stage lyme disease mimics _______.
syphillis
Prime mammalian reservoirs of lyme disease are _______ and _______.
deer; white-footed field mouse
Has caused more human deaths that any other bacterial disease in recorded history.
Plague
Among all infectious diseases, only ______ and ______ have killed more than the plague.
small pox; measles
Caused by Yersinia pestis, a Gram-negative, facultatively aerobic rod-shaped bacterium.
Plague
______ are intermediate hosts and vectors that spread plague between mammalian hosts.
Fleas
______ plague is enzootic among rodents
sylvatic plague
Most common form of plague is _______ plague, so called because of the ______ that develop in the infected individual.
bubonic; buboes
Buboes in bubonic plague are filled with
Yersinia pestis
In this disease, local hemorrhages produce dark splotches on the skin and eventual tissue necrosis.
bubonic plague
_______ plague occurs when Yersinia pestis reaches the lungs.
Pneumonic
_______ plague is the rapid spread of Yersinia pestis throughout the body.
septicemic
Plague can be treated with _____ and _____ if it is rapidly diagnosed.
gentamycin streptomycin
