HIV/AIDS discussion in micro

Where did HIV come from? Benign simian infection evolved into human

infection in the early 30s in southwest Africa Considered a chronic disease now Causes a depletion of CD4 cells

(lymphocyte receptor) Inserts genetic material on host DNA

creating a permanent infection

Strains of HIV There are many strains of HIV – can be

infected by 1+ viruses and get superinfection

Can pass on drug resistant strains AIDS defined: CD4 count <200/mm3,

Candidiasis (thrush), invasive cervical cancer, HIV dementia or wasting, Kaposi’s sarcoma, infections like mycobacterium

Kaposi’s

Kaposi’s Always purpleLike the leg w/ assoc. edema

CD4 Type of WBC that carries CD4 surface

marker and helps the body fight infection. Also known as Tcells or T helper cells. These cells incorporate the HIV RNA

About 140 viral replication cycles occur each year 10.3 X10^9 virions are produced each day

Transmission Heterosexuals on the rise

1985- 1.9%; 1997- 35% Higher risk in uncircumcised due to warm moist

environ. Of foreskin In Baltimore, 31% of IDU are HIV+ and 48% of all

new HIV cases were IDU in 2001 Blood transfusions – 1:450,000 false negative

blood tests Perinatal transmission – 1.2% of all AIDS cases Organ transplant – 10 since 1985 screening began

7 from same donor

transmission Household contact: 8 total; 4 child to child,

3 patient to care giver, 1 parent to child Deep kissing: 1 total; man with gingivitis

kissing a female One case of two females sharing a sex toy Health care worker to patient: 7 total; 6

from Florida dentist, 1 orthopedic surgeon

Statistics - globally People living with HIV – 39.4 mill New HIV infections in 2004 – 4.9mill Deaths due to AIDS in 2004 – 3.1mill About 14,000 new HIV infections/day in

2004 95% in low and middle income countries 50% are 15-24 year olds

In US highest age group is 25-44 yoa Fastest rate of increase is Black and South states

In Maryland, % of AIDS cases by location: Suburban Washington 32%, Suburban Baltimore 35%

Stats cont. Baltimore – 3rd highest AIDS rate in

2001 after New York and Miami with 50/100,000

Diagnosis to death with no treatment is 10-12 years

Acute HIV infection Syndrome after initial infection – 2-4

weeks after exposure, consists of fever, adenopathy, pharyngitis, rash, m/c Symptoms means more rapid

progression Seroconversion – 3 weeks after

transmission >95% of patients seroconvert within 5.8 mo.

Occupational exposure of 2001 57 seroconversions

46 percutaneous exposures 23 nurses

Infectious body fluid: blood, semen, vaginal secretions

Not infectious unless bloody: feces, urine, snot, spit, sweat, tears, vomit

Drug therapy Goal: increase CD4, decrease viral

load, prevent secondary infection Drug failures after 1 year: Baltimore

63% Why – drug side –effects such as head

ache, GI intolerance, peripheral neuropathy, lipodystrophy

Lipodystrophy – central fat accumulation, periphera wasting, lipoma

lipoma

lipodystrophy

Long term drug side effects Osteopenia, AVN, myopathy

(weakness), polymyositis, peripheral neuropathy (burning, aching or numb)– need vit D and Calcium