Person to Person Flashcards
Name the pathogen modes of transmission
Airborne bacterial/Viral
Direct viral/bacterial
STD
? important vehicles of transmission of person-person?
Aerosols
-coughing, talking, breathing,
contaminate surfaces/persons
Sneezes clock in at 100 m/s (200) can in
lots of bacteria and viruses
Most pathogens survive ? in air
Poorly
Only over short distances, lots of pathogens are gram + so more resistant to drying.
Major bacterial respirtaotry tract pathogens
Streptococcus pyogenes
Streptococcus pneumnoniae
Mycobacterium tuberculosis
Pertussis
Which are preventable by vaccination?
Diptheria and whooping cough
Streptococcus A pyogenes
commonly found in low numbers in upper resp. tract of healthy indv.
causes strept through and inner ear and skin
certain strains carry a bacteriopage that encode endotoxins. such as TSS/Scarlet fever- necrotizing fasciitis
Untreated infections can lead to rheumatic fever
Streptococcus Pneuooniae
Causative agent of pneumonia
is protected by capsule from immune system
drug resistant strains are common.
Capsular polysaccharide vaccine available
penicillin/erythromycin treatment.
Measles
(-) strains RNA- paramyxovirus
Formerly common childhood
Mumps
paramyxovirus (like measles)
effects inflammation salivary glands
Rubella
(3-day measles/german)
-Caused by ssRNA virus togavirus group
Colds
Most common- rhinoviruses \+ single sense ssRNA virus 115 diff. strains identified. 15% of colds - coronaviruses 10% adenoviruses
Enterovirus D68
Picornavirudae: Group IV + sense ssRNA genome naked nucleocapsid
-1 of >100 non-polio enteroviruses not new but caused nationwide outbreak in 2014.
causes severe illness such as wheezing.
Influenza
RNA virus of orthomyxovirus group
(-) negative strand ssRNA
8- segments
3 diff types of types
the most important human pathogen
influenza A
Viruses bind to cell
glycoproteins and sialic acid sugars on the surfaces of epithelial cells in lungs and throat.
Why do flu breakouts occur annually.
due to the plasticity of the influenza genome
Usually from recombination of avian and human virus in swine.
1918/2020
H1N1 outbreak 2009
h5n1 gradually on the rise
Antigenic shift
-Major change in the influenza virus antigen due to genome reassortment.
Antigenic drift
Minor change in influenza virus antigens to gene mutation; RNA replicase does not proof-read avg
1 mutation per viral genome
WHO announced how many ? confirmed cases
386 deaths
650
386 deaths
Explain the mortality
prevention
treatments
Due to secondary bacterial pneumonia infection
- immunization/ world surveillance
- Use of various drugs tamiflu/ relenza (zanamir)
- amantadine (synthetic amine inhibits replication)
- more effected when given early
Staphylococcus
gram + cocci; divides into several planes to form irregular clumps
causes acne,boils, impetigo, osteomyelitis, carditis
What strain of staphylococcus causes human disease
S. Aureus
3 virulence factors
Hemolysis
Coagulase
Leukocidin
Certain strains implicated with TSS
Cough, high fever, rash, vomitng
TTST-1 A super anitgen
What causes food poisioing
S. Enterotoxin A (superantigen)
Extensive use of antibiotics has resulted in
selection of resistant strains of s. Aureus
Hepatitis
A liver inflammation caused by vrisues or bacteria
these viruses are diverse (A,B,C)
Hep A
infectous hep
causes mild illness
oftten fecal-oral transmission
Group IV ss+ RNA picoRNAvirus
Contamiinated water, oysters, daycare
has vaccine available
Hep B
Serum
Acute/severe liver disease
-Part dsDNA/hepaDNAvirus
has vaccine avail
Hep C
Blood contact/ needles
No vaccine
Group IV flaviviridae (ss+RNA)
What 2 hep are parenteral transmission - blood bodily fluid?
B AND C
Less common forms of Hep?
D, E, G
D- coinfection with HepB
E- acute, self-limting
G- mild or asymptomatic
Vaccines for HEP only avail for ?
A and B
What is ebola caused by? kind of strand? How is it transmitted, where does it come from
Filovirus
Neg RNA virus
Reservoir is bats- fruit bats
Pathogens from where are exchanged during sex?
From the genitourinary tract
What do BACTERIAL STI’s are preventable and treatable
Gonorrhea and syphilis
Gonorrhea
prevalent, asymptomatic in women
AKA the clap
N. Gonorrheoae (gram neg cocci)
mild vaginitis that goes unnoticed, can lead to pelvic inflammation
Newborns can get eye infection/blood infection
Syphilis
Low prevalence and very obvious symptoms in women
Treponema pallidum
T. Pallidum can be transmitted to fetus
What are the symptoms of the clap in males
Painful infection of urethral canal
How many stages of syphillis
3
What is highly effected for the the first 2 stages of syphillis?
Penecillin
How many people annually get syphilis?
55,400
14,000 P/S DIAGNOSED
72% of new p&s among men having sex with men
Herpes Simplex Virus
Infections are associated with Anogenital region
- causes painful blisters on penis of male and cervix
- Typically transmitted through sexual contact and active blisters present
Genital herpes
incurable
limited number of drugs are succesful in controlling infectious blister stage
(acyclovir)
Chlamydia trachomatis
obligate intracellular bacterium
- Nongonococcal urethritis (NGU) - can cause infertity
- eye infection
- secondary infection
What can you use to detect chlamydia
gene probe, PCR, ELISA
Trichomoniasis The two key genera refer diplomonads and parabasalids are
NGU may be cases by this (vaginalis)
-transmitted via sex, tolet seats, etc
asymptomatic in males
Trichomonas is a ?
Parabasalid
lack mitochondria and have hydrogenosomes for anaerobic metabolism.
Genomes lack introns and are large.
Which HIV is more virulent
HIV-1
What is an opportunistic infection in AIDS patients??
Pneumonia
Explain HIV pathogenesis
HIV infects the cell that contains the CD4 cell surface protein then infection result in Progressive decline in CD4 cells especially CD4 T helper cells and HIV also interacts with co receptors On Target cell
