Acquired immune deficiency syndrome
() introduction:
*(AIDS) is a sever disease syndrome of the human immune system caused by the human immunodeficiency virus (HIV).
*This condition progressively reduces the effectiveness of the immune system and leaves individuals susceptible to opportunistic infections and tumors.
*Within several weeks to several months after infection , many persons develop an acute self-limited mononucleosis-like illness lasting for a week or two. Infected persons may then be free of clinical signs or symptoms for many months or years before other clinical manifestations develop
*AIDS is now a pandemic,
In 2007, an estimated 33.2 million people lived with the disease worldwide, and it killed an estimated 2.1 million people, including 330,000 children. Over three-quarters of these deaths occurred in sub-Saharan Africa, retarding economic growth and destroying human capital
*Although treatments for AIDS and HIV can slow the course of the disease, there is currently no vaccine or cure.
* Antiretroviral treatment reduces both the mortality and the morbidity of HIV infection, but these drugs are expensive and routine access to antiretroviral medication is not available in all countries.
*Due to the difficulty in treating HIV infection, preventing infection is a key aim in controlling the AIDS epidemic, with health organizations promoting safe sex and needle-exchange programmes in attempts to slow the spread of the virus.
*Diagnosis :
include a CD4 cell count below 200/mm3 regardless of the presence or absence of symptoms, or a CD4+T-lymphocyte percentage of total lymphocytes less than 14 %, regardless of clinical status . Advanced HIV infection characterized by a CD4 cell count below 50/mm3 .
*The clinical manifestation of HIV in infants & young children overlap with failure to thrive , inherited immunodeficiency & other childhood health problem
* Most persons infected with HIV develop detectable antibodies within 1-3 months after infection , occasionally , there may be a more prolonged interval of up to 6 months , with only very rare the antibodies developed after 6 months.
Symptoms
The symptoms of AIDS are primarily the result of conditions that do not normally develop in individuals with healthy immune systems. Most of these conditions are infections caused by bacteria, viruses, fungi and parasites that are normally controlled by the elements of the immune system that HIV damages.
Opportunistic infections are common in people with AIDS. HIV affects nearly every organ system.
People with AIDS also have an increased risk of developing various cancers such as Kaposi s sarcoma, cervical cancer and cancers of the immune system known as lymphomas. Additionally, people with AIDS often have systemic symptoms of infection like fevers, sweats (particularly at night), swollen glands, chills, weakness, and weight loss.
Infectious agent:
AIDS is the most severe acceleration of infection with HIV. HIV is a retrovirus . Two types have been identified : type 1 (HIV-1) & type 2 (HIV-2 ) . the pathogenicity of ( HIV-2) is lower than (HIV-1 )
*Reservoir : humans
Mode of Transmission :
*sexual intercourse ( vaginal sex is responsible for 70 to 80 percent of AIDS cases) , male-to-male sexual contact .
*the sharing of HIV contaminated needles and syringes, injection drug
*transfusion of infected blood or its components .
*transplantation of HIV infected tissue or organs .
*prenatal transmission , 15-30% of infants born to HIV infected mothers are infected before ,during , or shortly after birth ,
*breast feeding by HIV infected women can transmitted HIV.
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()() the risk of HIV transmission via sexual intercourse is much lower than most other sexual transmitted agents. The presence of a concurrent STDs , especially an ulcerative one like chancroid, can generally facilitate HIV transmission . the sexual risk behavior for AIDS like unprotected sexual intercourse with many concurrent or overlapping sexual partners
Incubation period : Variable . Although the time from infection to detecting of Antibodies is generally 1-3 monthes , & to the diagnosis of AIDS has range less than 1 year to 15 years or longer.
The median IPin infected infants is shorter than in adults
Period of communicability : begin early after onset of HIV infection and extend through out life . epidemiologic evidence suggests that infectiousness increase with increasing immune deficiency , clinical symptoms & presence of other STDs.
Susceptibility to infection :
Susceptibility is presumed to be general , race, gender & pregnancy do not appear to affect Susceptibility to HIV infection or AIDS . The presence of other STDs, especially those with ulcerations . adolescent & adults male and females who acquire HIV infection at an early age progress to AIDS more slowly than those infected at an older age .
METHODS OF CONTROL :
A-preventive measures:
1- Public and school education must stress that having multiple sexual partners and sharing drug & avoid or reduced risky behaviors
2- HIV counseling & testing site .
3- All pregnant women should be counseled about HIV early in pregnancy & to be tested for HIV infection as a routine part of standered antenatal care .
4- All donated units must be tested for HIV antibody , only donations testing negative can be used .
5- Physicians should adhere strictly to medical indications for transfusions.
6- Care should be taking in handling , using & disposing of needles or other sharp instruments.
7- BCG & oral polio vaccine are not recommended for HIV infected children regardless of symptoms . MMR are recommended for all HIV infected children.
B-control of patient , contact , & the immediate environment :
1- obligatory report to local health authority .
2- Isolation : Isolation of the HIV positive individual is unnecessary . Universal precautions apply to all hospitalized patients .
3- Concurrent disinfection : of equipment contaminated with blood or body fluid & with excretions and secretions visibly contaminated with blood or body fluid .