Flashcards in Infectious Diseases Deck (152)
How is HPV transmitted?
Direct epithelial-to-epithelial contact (sexually, vertically from mother to infant, oral mucosa)
Is HPV infection necessary before the development of cervical cancer?
Yes! However the infection must have been present for years
What type of cancers is HPV associated with?
Squamous cell carcinoma and adenocarcinomas of the cervix, penile / vulvar/vaginal cancers, squamous cell cancers of oropharynx
Which HPV serotypes are associated with most cancers?
HPV-16 and HPV-18
What are the other six HPV genotypes associated with the remaining 20% of cervical cancer?
HPV-31, -33, -35, -45, -52 and -58
Which HPV serotypes are associated with genital warts?
HPV-6 and HPV-11 are responsible for 90% of genital warts
What is the overall prevalence of HPV in canada?
11-29%, peak prevalence in young adults
What are risk factors for HPV infection?
# of sexual partners, early age of first intercourse, never being married, never being pregnant, immunosuppression
Which serotypes does the quadrivalent HPV vaccine protect against?
HPV-6, -11, -16, -18
When should the HPV vaccine be given?
Before acquisition of the virus
What is the efficacy of the vaccine against the development of pre-cancer lesions?
>98% (98% effective against dysplastic lesions, 100% effective against high-grade lesions, 99% effective against vaginal warts)
What is the vaccination schedule for the HPV vaccine?
Depends on age. If you are 9-14 yrs old and immunocompetent, you may receive 2-dose schedule (0 and 6-12 months). Otherwise, you should get 3-dose schedule (0,2,6 months).
Who does the CPS recommend receive the HPV vaccine?
Girls between 9-13 yrs of age, and all unimmunized females 13 yrs of age and older. Also: females who have had previous pap abnormalities or warts
What are the two vaccines approved in Canada for HPV?
Gardasil or Cervarix
What are infectious etiologies of genital ulcers?
- syphilis (treponema pallidum)
- chancroid (h. ducreyi)
- lymphogranuloma venereum (chlamydia)
- granuloma inguinale (donovanosis)
- secondary bacterial infection
How do you treat first episode of HSV infection?
7-10 days of oral acyclovir (if immunocompetent)
What type of virus causes Measles?
What are the symptoms of Measles?
- maculopapular rash
- Koplik's spots
What are some serious complications of measles?
- encephalitis (1/1000 cases)
- death (2-3/1000 cases)
What is a rare long-term sequelae of measles infection?
subacute sclerosing panencephalitis (SSPE) - can occur 7-10 yrs after the primary infection
When is a person with measles infectious?
From 4 days before the rash until 4 days after the rash
What is the incubation period of the measles virus?
approx 14 days (range 7-21)
How many people die from measles each day (in the world)?
What type of vaccine is available against measles?
live-attenuated (as part of the MMR)
What are recommendations for unvaccinated children who are travelling?
- children ages 6-11 months who travel internationally should receive one dose of the MMR vaccine 2 weeks before leaving
What type of isolation should someone with suspected measles have?
What is the treatment of measles?
Supportive care! No anti-virals indicated. Severe cases can be treated with Vitamin A (age specific dosing)
What type of strep causes "strep throat"?
Group A streptococcus (GAS) aka streptococcus pyogenes
What type of bacteria is GAS?
gram positive coccus in chains