Lecture 16: STI's B Flashcards
Human Papillomavirus Virus
Causes genital warts and cervical
cancer
Globally, __________
cancer is the second
most frequent cancer
in Women.
Cervical
HPV Transmission
-Majority of transmissions occur as a result of sexual
contact or close personal contact
-Condoms appear to reduce transmission, but do not
provide complete protection.
What type of HPV causes: most cervical cancer cases?
16, 18
What type of HPV causes most genital wart cases?
6,11
Broadly describe the mechanism of HPV disease
1- Microabrasions in mucosa
2- Infects basal katatinocytes
3- Differentiate and move into distal mucosa
4- Viral assembly as cells move into mucosa
5- Infectious virus sheds
6- Chromosomal integration
On the order of _______, HPV progresses to invasive carcinoma. It moves from low-grade to high-grade _____________ __________ ________ and then eventually, invasive carcinoma
Years
squamous intraepithelial lesions
How do clinicians diagnose HPV?
Clinical signs, PAP, virus culture, PCR
Why is serology not useful in diagnosing HPV?
High levels of seroprevalence
How is HPV treated following a diagnosis?
Local therapy: imiquimod immune enhancer
Liguid nitrogen or surgical removal
How do we prevent HPV?
Vaccine, which contains 6,11,16, and 18 which are accounted for 95% of cervical cancers
What vaccine technology is used in HPV inocculation?
Recombinant technology where proteins for virus-like particles (VLPs) of the L1 protein
Non-infectious
Not live biological products
What type of virus are HSV?
DNA viruses; HSV1 is more common
What is the most common cause of genital ulcers?
Herpes virus
When is herpes contagious?
Before the lesions appear, reccurrence is more common in HSV-2 in the genital area
HSV-1 is commonly found…
Above the belt, humans only natural host
HSV-2 is found…
Below the belt
Talk about the pathophysiology of HSV
Lifelong infection, replicates in host nucleus, neurotropic, neuroinvasive replilcates in 8-16h
What leads to HSV transmission?
Contact with mucous membrane, reactivation linked to stressors
How is HSV treated?
Antiviral therapy- Acyclovir
Reduces risk of transmission to partners, not a cure
What is more severe? A reccurent episode following intensive stress or the primary episode of an HSV infection ?
Primary
HIV has tropism for _______ of the host ________ system
CD4 T cells, immune
Where does HIV replicate?
In host CD4 T cells and macrophages
How is most HIV transmitted?
Sex
What chanes the chances of HIV transmission?
Amount of virus, amount of target cells in HIV-neg person, type of sex, presence of viral and bacterial co-infections
Describe the stages of an HIV infection
In the acute phase, theres a rapid increase in HIV and killer cells, while helper T-cells decline. Antibodies begin to rise
Over next decade…
T-cells-decrease
Antibodies- initially increase then rapidly decline approaching aids
Killer cells- initial rise and decline
HIV load- increases
Once we reach AIDS,
Increase in HIV, decrease in all other factors
Where do we find CD4 T cells?
Blood and variosu anatomical sites
HIV replicaes at various mucosal sites in the female and male genital tract
When is RNA highest in a patient’s semen?
In the initial phases, during seroconversion and in the acute infection phase over the first few weeks. Then there is a decline and the an increase as the client develops AIDS
What happens with each STI episode or reactivation?
An increase in HIV RNA levels, this is tied to disease progression and risk of transmission
Name some biological factors that increase a client’s risk for HIV
Transmission: changing blood viral load, genital viral load, stage of infection
Susceptibility: number of target cells, immune activation, tissue type, genetic factors
Lab testing for HIV
HIV EIA tests for P24 antigen and gp120 antibody
Positive test? Western blot
(blood)
What is the most common CURABLE STI in USA?
Trichomonas vaginalis
Trichomonas Vaginitis
Protozaon parasite,
70% infections are asymptomatic
Dx: Wet mount
