Quiz 4 Bugs Flashcards
What are the main microbes associated with STD’s?
Bacterial - gonorrhea, syphilis, chlamydia
Protozoan - Trichomonas vaginalis
Arthropod - Lice, scabies
Viral - HIV, HPV, HSV
What is the most common STD in Utah, and most serious STD?
Chlamydia is most common, Syphilis is most serious.
What defines urethritis? And how do you treat it?
Visible drip from penis or WBCs seen on urethral gram stain. Usually accompanied by dysuria. The causes are nongonococcal urethritis (chlamydia, mycoplasma genitalium) or gonococcal urethritis (neiserria gonorrhoeae).
- For nongonococcal urethritis and cervicitis, use azithromycin.
- For gonococcal urethritis (gonorrhea), treat it with ceftriaxone, but you might have to use azithromycin for severe beta-lactam allergies.
What other diseases are associated with Mycoplasma genitalium?
Urethritis, cervicitis, endometritis, PID. Treat it will azithromycin as well because it is nongonococcal.
How do you diagnose gonococcal urethritis (gonorrhea)?
Might have rashes behind ear or on side of body as well as purulence coming from urethra. Do a urethral gram stain, should show gram-negative diplococci. Do a NAAT, nucleic acid amplification testing of urine or swab.
What are the complications of gonorrhea and chlamydia?
Infertility, epididymitis, PID, disseminated gonococcal infection in joints and skin, neonatal infection. Epididymitis is usually uniteral and involves whole testicle and spermatic cord. Treat with ceftriaxone, 3rd generation ceph. PID is caused by STD agents and by infection with normal GU flora like gardnerella vaginalis for GBS. Has tenderness around groin.
What is bacterial vaginosis?
Lactobacillus is replaced by anaerobes like gardnerella vaginalis, and is associated with STD’s. You have clue cells with these which are anaerobic bacteria attached to cells, and this is a fishy odor, white discharge. Treat with metro.
What is Trichomonas vaginalis?
Associated with HIV transmission. Is a green and frothy discharge. Has flagella on back.
What is genital herpes?
Sores, and bumps or blisters, dysuria, vaginitis. Culture to see if HSV1 or HSV2. You can get HSV1 on genitals and vice versa, but probably won’t have reoccurrence. Treat with acyclovir.
What is syphilis?
Caused by Treponema pallidum, which is a spirochete. Screen with syphilis IgG ELISA. You get chancres as a primary disease, red bumps on hands as secondary disease, and tertiary or untreated syphilis can spread to bone, brain, heart and is scary. Treat with Benzathine.
What is genital warts?
HPV. HPV6 and HPV11 cause 90% of all cases. Most go away within a year without intervention.
What is HAART and when did it start?
Highly Active AntiRetroviral Therapy. Mid 1990’s.
Where did HIV arise from?
From SIV in equatorial Africa in early 20th century. SIV is from african monkeys. HIV-1 was a zoonosis from primates. Then the cutting of these monkeys led to this disease spread. Subtype B is most common type of HIV-1 in US. HIV-2 should disappear in coming decade.
What is HIV?
An enveloped retrovirus. Two copies of SS RNA contained within capsid. ENV protein on lipid membrane is only part of virus exposed, rest of virus becomes part of human cell. The virion contains three enzymes: RT, integrase, and protease. The gene of these is pol. The virus enters, then inside in the cytoplasm is does reverse transcriptase (mRNA template used to synthesize dsDNA), is now a double stranded DNA, then integrates into nucleus and becomes part of human chromosome, and is a pro-virus for inflammation. Then is assembles, buds, and releases from the cell, and matures outside.
What are the three structural genes that all retroviruses have?
- gag
- pol (RT, integrase, protease)
- env
Which receptors does the virus need to get in a cell?
It must have a CD4 receptor, and either a CCR5 or CXCR4 chemokine receptor. The target cells are CD4+ T cells, DC’s, and macrophages. Once you hit less than 200 CD4+ count, it is considered AIDS now. The viral load determines the rapidity of T cell decline.
Who should get tested for HIV?
Everyone aged 13-75, prego’s, high risk groups. Who is at risk? injection drug users, MSM, etc.
How to diagnose HIV?
ELISA and Western blot (chronic), as well as detection of HIV antibodies (acute has viral load, has fever, malaise, lymphadenopathy, rash). HIV antibodies are detectable within 3 weeks of primary infection and remain detectable for life. You might get a false negative if within 3 weeks, but you would still have the virus so do a PCR. Pregnancy, mono, flu, autoimmune disease can all cause false positives. On the CD4 count chart, there is a huge drop, then after 5 weeks it rises halfway back up, and then slowly drops over the next 10 years to under 200. Meanwhile the HIV virus in plasma line does the exact opposite.
What is the worst type of AIDS?
C3, less than 200 CD4 count. A1 is asymptomatic with still high CD4 count above 500.