HIV

Question 1

introduction

Answer 1

-causes AIDS (acquired immunodeficiency syndrome)
-AIDS- June 1982
-single stranded RNA virus (member of Retroviridae family and Lentivirus genus)
-depletion of CD4 and T lymphocytes - important feature of host immune response
-2 types: HIV1 and HIV2
-HIV1- occurs across globally
-HIV2- primarily Africa
-HIV1 more easily transmitted and progresses more quickly

Question 2

transmission of HIV

Answer 2

-exposure to bodily fluid
-unprotected sex is most common mode of person to person
-bodily fluids is also common - blood
-seronegative individuals can become infected by single contaminated unit of blood
-healthcare setting- nick, puncture, or other direct exposure to bodily fluids of infected cases
-0.4% seroconversion rate among healthcare workers who suffered percutaneous injuries with HIV contaminated surgical instruments
-greatest risk among healthcare workers who care for advanced HIV/AIDS pts with high viral loads

Question 3

environmental transmission HIV

Answer 3

-unlikely
-virus typically undergoes rapid inactivation once outside host
-virus may survive up to 3 days under certain circumstances
-transmission without sexual or percutaneous (via skin) exposure in domestic settings is extremely remote
-no evidence exists of transmission via sharing of contaminated linens, towels, washcloths, cooking utensils, drinking cups. toilet seats

Question 4

clinical aspects of HIV/AIDS

Answer 4

-once infection has occurred- host immune system attempts to eradicate (unsuccessfully) HIV virus
-intially presents as flulike syndrome that may wax and wane over several weeks or months
-CD4 + T cell count decreases
-as infection progresses -> HIV producing host cell increase and steadily deplete CD4 + T cells
-once HIV establishes itself -> oft-protracted asymptomatic period commences that ranges from 1 - 15 years or more
-average interval is about decade

Question 5

CDC/WHO guidelines

Answer 5

-established useful criteria for clinical progression of HIV:
-HIV seroconversion illness
-clinical latent period
-early symptomatic infections
-AIDS
-each is characterized by distinct features

Question 6

laboratory guidelines for HIV

Answer 6

-positive test result for HIV antibody followed by confirmatory test or positive identification of HIV RNA or DNA, HIV p24 antigen or isolation of HIV virus

Question 7

stage 1

Answer 7

-absence of an AIDS defining condition (opportunistic infections) AND CD4 titer > or equal to 500 cells OR CD4 titer > or equal to 26 of total lymphocytes

Question 8

stage 2

Answer 8

-absence of AIDS defining condition (opportunistic infections), CD4 + titer 200-499 cells OR CD4 titer >14-25% total lymphocytes

Question 9

stage 3

Answer 9

-CD4+ titer < 200 OR CD4+ titer < 14% of total lymphocytes OR documented stage 3 defining condition (opportunistic infection)

Question 10

early symptomatic infection stage

Answer 10

-may progress for years prior to satisfying criteria for AIDS
-may develop persistent generalized lymphadenopathy (PGL) that involves 2 nonadjoining anatomical sites
-may also begin to suffer conditions such as herpes zoster; oral candidiasis; episode of fever, weight loss, diarrhea, Guillain Barre syndrome
-clear indicators of clinically apparent immune dysfunction, all of which point to progression towards AIDS

Question 11

CD4+ T cells < 500

Answer 11

-develop array clinical symptoms such as fevers, night sweats, oral candidiasis, diarrhea, weight loss, collectively called the AIDS-related complex (ARC)
-also may begin to suffer opportunistic infections
-during early symptomatic period opportunistic infections are typically not life threatening
-AIDS requires established serological evidence of HIV as well as either CD4+ T cells titer < 200, CD4+ T cells < 14% of total number of lymphocytes, or documented presence of any stage 3 AIDS defining illnesses
-4 groups- opportunistic infections (cryptosporidiosis) malignancies (invasive cervical cancers), neurological disorders (toxoplasmosis of the brain), and clinical syndromes (nigh sweats and diarrhea)

Question 12

HAART

Answer 12

-highly active antiretroviral therapy (HAART) provides the cornerstone of HIV/AIDS treatment
-commonly used HAART in US are single therapy bacavir and triple therapy abacavir/dolutegravir/lamivudine
-target virus by preventing its replication in host cells
-global estimates suggest > 30 mil people living with HIV/AIDS
-of that number, about 12 mil were female and 1 mil were children
-cumulative AIDS mortality neared 12 mil

Question 13

prevention of HIV/AIDS

Answer 13

-vaccine not yet available
-several potential candidate are currently in clinical trial in sub-saharan africa
-aggressive efforts with particular emphasis on abstinence and/or consistent safe sex practices
-programs utilize behavioral interventions, education based attitudinal change, and other strats
-behavioral interventions emphasize voluntary HIV testing, appropriate counseling, and aggressive HAART treatment for HIV + individuals
-targeted compliance strats use technology based reminders (Like texts) not only to improve regular retroviral medication adherence but also to reinforce consistent condom use

Question 14

Truvada preexposure prophylaxis (PrEP)

Answer 14

-used to prevent HIV
-FDA approved to treat HIV In 2004, 8 years later approved for preexposure prophylaxis
-combination of 2 drugs -> tenofovir and emtricitabine
-daily
-significantly reduce risk of infection
-intended for HIV neg individuals who are at significant risk for infection
-studies have shown 2/3rds of users intended to decrease or stop condom use
-another 2/3rds reported they would likely engage in more high risk sexual behavior

Question 15

who should get PrEP

Answer 15

-hiv neg people in ongoing sexual relationship with HIV + partner
-homosexual or bisexual men not presently in monogomous relationship with recently tested HIV neg partner who have reported unprotected anal sex < or equal to 6 months or has received an STI dx during that period
-nonmonogamous heterosexuals in relationship with HIV neg partner who do not consistently use condoms with partners of unknown HIV status who are at increased risk for infection
-includes IV drug users or people with hx of bisexual male partners or HIV status is unknown and who are at increased risk of HIV infection (people who inject drugs or have bisexual male partners)
-people who have used IV drugs < or equal to 5 months or who have enrolled in substance abuse treatment program

Question 16

kaposi’s sarcoma

Question 17

CD4 count < or equal to 150

Answer 17

-people in hyperendemic areas
with CD4 counts ≤150 should start
primary prophylaxis against
histoplasmosis**
-> itraconazole 200 mg by mouth daily.
-Prophylaxis can stop if CD4 counts rise and stay above 150 for at least 6 months
-If pt develops active disease -> for moderate to severe disseminated histoplasmosis -> IV amphotericin B for at
least 2 weeks followed by daily itraconazole for at least 12 months

Question 18

CD4 count < or equal to 100

Answer 18

-toxoplasmosis*
-Toxoplasma gondii intracellular protozoa causing encephalitis in individuals with low CD4 counts, typically ≤50
-Primary infection- asymptomatic acquired from ingestion of cysts in undercooked meat or oocysts found in cat feces and litter boxes
-vast majority occurs via the reactivation of
tissue cysts in immunocompromised hosts
-prophylaxis indicated for pts with CD4 counts ≤100 and previous exposure to toxoplasmosis (IgG positive).
-TMP/SMX- preferred prophylactic agent
-Dapsone, dapsone and pyrimethamine with leucovorin, atovaquone, or atovaquone
and pyrimethamine with leucovorin are alternatives to TMP/SMX in sulfa-allergic pts
-Toxoplasmosis encephalitis can present as a new focal neurologic deficit -> hemiparesis or speech deficit, seizure,
or coma
-Other symptoms -fever, headache, and altered mental status
-CT or MRI reveals multiple ring enhancing lesions
-dx confirmed via lumbar puncture and
PCR testing of CSF for toxoplasmosis.
-Preferred treatment is pyrimethamine and sulfadiazine with leucovorin

Question 19

CD4 Count ≤50

Answer 19

-Mycobacterium avian complex (MAC) caused by -> Mycobacterium avium or M. intracellulare
-present as either localized or disseminated
-Localized disease- lymphadenitis with fever
-disseminated disease-fever with abdominal pain and diarrhea.
-if disseminated MAC infection suspected -> mycobacterial blood cultures
-Blood cultures in localized disease will be negative
-Primary prophylaxis against MAC- should be started without active MAC infections and CD4 counts ≤50.
-Preferred prophylaxis- azithromycin or
clarithromycin -> rifabutin can be used as an alternative option
-Treatment for active infections-azithromycin or clarithromycin plus ethambutol with or without rifabutin

Question 20

early signs of HIV

Answer 20

-fever and chills
-headache and mood swings
-sore throat, swollen lymph nodes and mouth ulcers
-muscle and fatigue and aches
-nausea, vomiting and loss of appetite
-joint pain
-clamminess rashes and blueness of skin
-women- change sin menstruation, lower belly pain, yeast infection
-high heart rate and low blood pressure
-pneumonia, cough with phlegm, shortness of breath and chest pain

Question 21

for AIDS

Answer 21

200

Question 22

HIV: tuberculosis

Answer 22

-pts with HIV higher risk
-can occur at any CD4 count
-screened with PPD regardless of CD4 count
-latent TB should be treated to prevent potential reactivation to active TB

Question 23

HIV: oral candidiasis

Answer 23

-thrush
-can occur at any CD4 count
-can occur any time for HIV+
-less common with CD4 counts > or equal to 500
-incidence increases as CD4 become lower (<200)
-recurrent infection sign of HIV disease progression
-treatment- oral fluconazole daily for 1-2 weeks
-nystatin swish and swallow 4-5x day for 1-2 weeks or clotrimazole troches 4-5 x for 1-2 weeks

Question 24

HIV: kaposi sarcoma (KS)

Answer 24

-AIDS-defining illness
-occur with any CD4 count
-more common when CD4 count drops below 250
-the cancer is caused by HHV8
-typically presents as red, purple, brown or black papular lesions on skin or mucous membranes
-bacillary angiomatosis (BA) may have a similar appearance

Question 25

HIV: coccidiodomycosis

Answer 25

-endemic regions are at greater risk of infection when CD4 drop 250
-CD4 count < 250
-pts with CD4 < 250 should be screened serologically (IgM/IgG) 1-2x year
-+ result may indicate active disease
-asymptomatic pts with + serological findings should be treated with daily fluconazole until CD4 rises to > 250

Question 26

HIV: bacterial pneumonia

Answer 26

-can acquire at any time but risk increases with CD4 < 200
-CD4 < 200 should be vaccinated against strep pneumoniae using 23-valent polysaccharide pneumococcal vaccine 1x every 5 years

Question 27

HIV: pneumocystis pneumonia

Answer 27

-AIDS defining illness
-CD4 < 200
-caused by yeast like fungus pneumocystis jirovecii
-fever, chills, nonproductive cough, chest pain, dyspnea
-dx should be suspected in susceptible pts with above symptoms
-chest x-ray can be normal early in course of disease but reveals bilateral ground glass interstitial infiltrates in butterfly pattern
-dx confirmed via sputum or broncheoalveolar lavage
-prophylaxis with TMP/SMX should be initiated in pts with CD4 counts < 200
-sulfa allergic pts- dapsone, dapsone + pyrimethamine with leucovorin, aerosolized pentamidine, or atovaguone as alternatives to TMP/SMX
-TMP/SMX is preferred treatment of active disease -> Add prednisone for more severe illness

Question 28

Truvada preexposure prophylaxis (PrEP)

Answer 28

tenofovir and emtricitabine

Question 29

-highly active antiretroviral therapy (HAART)

Answer 29

-single therapy bacavir OR
-triple therapy abacavir/dolutegravir/lamivudine