HIV

ACQUIRED IMMUNODEFICIENCY

SYNDROME
(HIV infection, AIDS)

What is HIV?

HIV stands for Human Immunodeficiency Virus.
(HIV) is a type of virus called a retrovirus, which infects humans when it
comes in contact with tissues such as those that line the vagina, anal area,
mouth, eyes, or through a break in the skin.
HIV infection is generally a slowly progressive disease in which the virus is
present throughout the body at all stages of the disease.
When HIV grows (that is, by reproducing itself),it acquires the ability to
change (mutate) its own structure. This mutation enables the virus to become
resistant to previously effective drug therapy
What are the stages of HIV ?
Three stages of HIV infection:
1- The initial stage of infection (primary infection), which occurs within weeks
of acquiring the virus, and often is characterized by a flu- or mono-like
illness that generally resolves within weeks.
2- The stage of chronic asymptomatic infection(meaning a long duration of
infection without symptoms) lasts an average of eight to 10 years.
3- The stage of symptomatic infection, in which the body's immune (or defense)
system has been suppressed and complications have developed, is called the
acquired immunodeficiency syndrome (AIDS).
What is the difference between HIV and AIDS?
Being infected with HIV does not mean that one has AIDS, but if left undiagnosed
and/or untreated, HIV infection damages the immune system and can progress to
AIDS.


How Does HIV Harm the Body?
• The human immunodeficiency virus is best known for targeting the T cells
of the Immune system (CD4 cells).
• Once it has attacked and moved into a T cell, it converts that cell into
a miniature virus factory. Eventually there are so many new viruses in the cell
that the T cell explodes, scattering the HIV back into the bloodstream. The
virus then moves on to fresh T cells and repeats the process. Over time, the HIV
can destroy virtually all of an infected person's T cells in this manner.
Epidemiology
n nGlobally, AIDS caused an estimated 3.1 million deaths in 2003 (2.5–3.5
million)

n nThe epidemic has continued growing, with estimates of 5 million new
infections (4.2–5.8 million) and 2.5 million children (2.1–2.9 million)
living with HIV/AIDS.

Identification

Emergence was in 1981 of a cluster of diseases associated with loss of cellular
immunity in adults who had no obvious reason for presenting such immune
deficiencies.


n nWithin several weeks to several months after infection with HIV, many persons
develop an acute self-limited mononucleosis-like illness lasting for a week or
two. They may then be free of clinical signs or symptoms for months or years
before other clinical manifestations develop.
AIDS Associated Disease Categories
1. Gastrointestinal: Cause most of illness and death of late AIDS.
Symptoms:
¡ ¡Diarrhea
¡ Wasting (extreme weight loss)
¡ Abdominal pain
¡ Infections of the mouth and esophagus.
Pathogens: Candida albicans, cytomegalovirus, Microsporidia, and
Cryptosporidia.
2. Respiratory: 70% of AIDS patients develop serious respiratory problems.
Partial list of respiratory problems associated with AIDS:
n nBronchitis
n Pneumonia
n Tuberculosis
n Lung cancer
n Sinusitis
n Pneumonitis


3. Neurological: Opportunistic diseases and tumors of central nervous system.
Symptoms many include: Headaches, peripheral nerve problems, and AIDS dementia
complex (Memory loss, motor problems, difficulty concentration, and paralysis).

4. Skin Disorders: 90% of AIDS patients develop skin or mucous membrane

disorders.
n nKaposi’s sarcoma
¡ ¡1/3 male AIDS patients develop KS
¡ Most common type of cancer in AIDS patients
n nHerpes zoster (shingles)
n Herpes simplex
n Thrush
n Invasive cervical carcinoma
5. Eye Infections: 50-75% patients develop eye conditions.
n nCMV retinitis
n Conjunctivitis
n Dry eye syndrome

Infectious agent

n nHuman immunodeficiency virus (HIV),
n Retrovirus.
n Two serologically and geographically distinct types with similar
epidemiological characteristics, HIV-1 and HIV-2, have been identified.
n The pathogenicity of HIV-2 may be lower than that of HIV-1
n lower rates of mother-to-child transmission for HIV-2.


Structure of the Human Immunodeficiency Virus HIV is a Retrovirus
Occurrence
n nOf the estimated 40 million persons (34–46 million) living with HIV
infection or AIDS (HIV/AIDS) worldwide in 2003, the largest elements were
estimated at 25–28.2 million in sub-Saharan Africa, 4.6–8.2 million in south
and southeastern Asia, 1.3–1.9 million in Latin America and 800 000–1
million in North America.

n nHIV-1 is the most prevalent HIV type throughout the world;

n HIV-2 has been found in Africa
Reservoir
n nHumans.
n HIV is thought to have recently evolved from chimpanzee viruses.

Mode of transmission

n nPerson to person transmission through unprotected (heterosexual or
homosexual) intercourse;

n nContact of abraded skin or mucosa with body secretions such as blood, CSF or

semen;


n nThe use of HIV-contaminated needles and syringes, including sharing by
intravenous drug users; transfusion of infected blood or its components

n nTransplantation of HIV-infected tissues or organs.

n nThe presence of a concurrent sexually transmitted disease, especially an
ulcerative one, can facilitate HIV transmission.

n nUnprotected intercourse (no condom— unprotected sex) with many concurrent

or overlapping sexual partners.

n nHIV can be transmitted from mother to child (MTCT or vertical transmission).

¡ ¡From 15% to 35% of infants born to HIV-positive mothers are infected
through placental processes at birth.

¡ ¡HIV-infected women can transmit infection to their infants through

breastfeeding and this can account for up to half of mother-to-child HIV
transmission.

¡ ¡Giving pregnant women antiretrovirals such as zidovudine results in a

marked reduction of MTCT.
n nAfter direct exposure of health care workers to HIV-infected blood through
injury with needles and other sharp objects, the rate of seroconversion is less
than 0.5%, much lower than the risk of hepatitis B virus infection after similar
exposures (about 25%).
n Unsafe injections may account for up to 5% of transmission.


n nWhile the virus has occasionally been found in saliva, tears, urine and
bronchial secretions, transmission after contact with these secretions has not
been reported.

n nNo laboratory or epidemiological evidence suggests that biting insects have
transmitted HIV infection.

Incubation period

n nVariable.

n nAlthough the time from infection to the development of detectable antibodies
is generally 1–3 months, the time from HIV infection to diagnosis of AIDS has
an observed range of less than 1 year to 15 years or longer.

n nThe median incubation period in infected infants is shorter than in adults.

Period of Communicability
n nNot known precisely; begins early after onset of HIV infection and presumably
extends throughout life.

n nInfectivity during the first months is considered to be high; it increases

with viral load, with worsening clinical status and with the presence of other
STIs.
Susceptibility
n nThe presence of other STIs, especially if ulcerative, increases
susceptibility, as may the fact of not being circumcised for males, a factor
possibly related to the general level of penile hygiene.


Interactions between HIV and other infectious disease agents
Mycobacterium tuberculosis infection:

n nPersons with latent tuberculous infection who are also infected with HIV

develop clinical tuberculosis at an increased rate, with a lifetime risk of
developing tuberculosis that is multiplied by a factor of 6–8.

n nThis interaction has resulted in a parallel pandemic of tuberculosis.

n nin some urban sub-Saharan African populations where 10%–15% of the adult
population have dual infection (Mycobacterium tuberculosis and HIV),

n nOther adverse interactions with HIV infection include pneumococcal infection,

non-Typhi salmonellosis, falciparum malaria and visceral leishmaniasis.

Methods of control

A. Preventive measures:
n nHIV/AIDS prevention programs can be effective only with full community and
political commitment to change and/or reduce high HIV-risk behaviours.


n nPublic and school health education must stress that having multiple and
especially concurrent and/or overlapping sexual partners or sharing drug both
increase the risk of HIV infection.

n nIn other situations, latex condoms must be used correctly every time a person

has sexual intercourse.

n nExpansion of facilities for treating drug users reduces HIV transmission.

n nHIV testing and counselling is an important intervention for raising
awareness of HIV status, promoting behavioural change and diagnosing HIV
infection. HIV testing and counselling can be undertaken for:
¡ ¡a) persons who are ill or involved in high-risk behaviours,
¡ b) attenders at antenatal clinics, to diagnose maternal infection and prevent
vertical transmission;
¡ c) couple counselling (marital or premarital);
¡ d) anonymous and/or confidential HIV counselling and testing for the
«worried well».

n nAll pregnant women must be counselled about HIV early in pregnancy and

encouraged to undertake an HIV test as a routine part of standard antenatal
care.


n nThose found to be HIV-positive take a course of ARV treatment, to reduce the
risk of their infant being infected.

n nAll donated units of blood must be tested for HIV antibody; only donations

testing negative can be used.

n nPeople who have engaged in behaviours that place them at increased risk of

HIV infection should not donate plasma, blood, organs for transplantation,
tissue or cells (including semen for artificial insemination).

n nOnly clotting factor products that have been screened and treated to

inactivate HIV must be used.

n nCare must be taken in handling, using and disposing of needles or other sharp

instruments.

n nHealth care workers should wear latex gloves, eye protection and other

personal protective equipment in order to avoid contact with blood or with
fluids.

n nWHO recommends immunization of asymptomatic HIVinfected children with the EPI

vaccines; those who are symptomatic should not receive BCG vaccine.


n nLive Measles-Mumps-Rubella and polio vaccines are recommended for all
HIV-infected children.

B. Control of patient, contacts and the immediate environment:

n n1) Report to local health authority: Official reporting of AIDS cases is
obligatory in most countries.
n Official reporting of HIV infections is required in some areas,

n n2) Isolation: Isolation of the HIV-positive person is unnecessary,

ineffective and unjustified.

n nUniversal precautions apply to all hospitalized patients.

n n3) Concurrent disinfection: Of equipment contaminated with blood or body
fluids and with excretions and secretions visibly contaminated with blood and
body fluids by using bleach solution or germicides

n n4) Quarantine: Not applicable.

n n5) Immunization of contacts: Not applicable.


n n6) Notification of contacts and source of infection: The infected patient
should ensure notification of sexual and needle sharing partners whenever
possible.

Management

n nAIDS must be managed as a chronic disease; antiretroviral treatment is
complex, involving a combination of drugs: resistance will rapidly appear if a
single drug is used.

n nThe drugs are toxic and treatment must be lifelong.

n nIn addition; treatment of other additional associated conditions

n nC. Epidemic measures: HIV is currently pandemic, with large numbers of
infections reported in the Africa, the Americas, southeastern Asia, and Europe.

n nD. Disaster implications: Emergency personnel should follow the same

universal precautions as health workers.

n nInternational measures: The United Nations Joint Programme on HIV/AIDS

(UNAIDS), which coordinates UN activities, and WHO do not endorse measures such
as requirements for AIDS or HIV examinations for foreign travellers prior to
entry.