HIV Testing and Care
TESTING FOR HIV
Antibody tests are used for screening of children (>2 years of age)
and adults for HIV infection and takes place in 2 phases. Antibody
tests are based on the fact that persons infected with HIV will develop
specific antibody responses within 3-6 weeks of the exposure. Screening
antibody tests (ELISAs) are highly sensitive, but may have false
positive results (test says HIV is present but this is not the truth),
therefore, positive ELISA antibody results must be confirmed with
western blot antibody testing, which is more specific, but also more
complicated and expensive. In the U.S. confirmatory testing is
performed on the same blood sample as the ELISA and usually does not
require an additional blood sample.
Nucleic acid-based tests (NATs) are designed to detect actual HIV RNA
in the blood by using PCR to amplify a specific HIV gene sequence. These sequences can usually be detected as early as 12 days following
infection. Because they are expensive, NATs are not used for
screening, but can be used as an additional confirmatory test. Modifications of NATs such as the RT-PCR can also be used to quantify
the actual amount of HIV present in blood plasma. Quantitative RT-PCR
tests are used to monitor the viral load in persons already known to be
infected with HIV.
Rapid tests are performed on blood, saliva, or oral mucosal cells, and
are used in certain point-of-care testing situations, but should be
confirmed with antibody or NAT testing.
LIVING WITH HIV
Immunology Terminology
CD4 cells (aka helper T cells) are part of the cell-mediated immune
system and are especially important in controlling viral and fungal
infections, and in regulating B cell (antibody) immune function. CD4
cells are the major target of HIV infection, and their numbers decline
with advancing HIV disease. These declines in CD4 numbers increase the
risk of opportunistic infections, particularly from herpes viruses such
as cytomegalovirus and Ebstein Barr Virus. Risk of fungal disease from
candida and pneumocystis also increase with increasing
immunosuppression. Absolute CD4 cell numbers, and the percent of CD4+
cells among circulating T cells are routinely monitored to help assess
immune system damage from HIV infection. CD4 percentage is usually
less variable than CD4 cell number.
IMMUNOSUPPRESSION CLASSIFICATION IN ADOLESCENTS AND ADULTS
Immune suppression status |
CD4 cell number |
CD4 percent |
Normal |
>500 |
>29 |
Moderate |
200-499 |
14-28 |
Severe (AIDS-defining) |
<200 |
<14 |
ROUTINE CARE AND FOLLOW UP
Pediatric HIV patients should be seen routinely every 3 months. During these visits, they are monitored for any intercurrent illnesses or changes in physical condition. Medication problems and adherence are also assessed, and CD4 counts and viral loads are measured.
HIV/AIDS Treatment
The most common and effective treatments of HIV/AIDS are called
antiretroviral drugs, which slow down the disease process of HIV/AIDS.
It has been discovered that a mix of antiretroviral drugs is needed to
maintain a successful treatment. This is also referred to as highly
active antiretroviral drugs, or HAART.
MEDICAL COMPLICATIONS
Patients with HIV infection have the same health problems as uninfected
persons, including viral respiratory illnesses, pneumonia, sinusitis,
and asthma most commonly, though these may occur with greater frequency
than in the general population. With increasing immunosuppression,
they have a greater risk of developing opportunistic infections (those
that occur in the setting of weakened immune systems). Some of the
more common opportunistic infections are serious bacterial infections
(pneumonia, bacteremia), oropharyngeal or esophageal candidiasis,
shingles, recurrent herpes, mycobacterium avian complex (MAC),
pneumocystis pneumonia. Central nervous system disease either from HIV
itself, toxoplasmosis, lymphoma, or JC virus can result in declines in
motor and cognitive function.
PSYCHOSOCIAL COMPLICATIONS
Children and adolescents with HIV infection may suffer the consequences
of certain parental risk factors which led to maternal infection such
as drug use or prostitution, and often reside in economically or
emotionally unstable environments. The parents may be ill or deceased,
or the children live with other relatives, or reside in foster care or
adoptive homes. Some children may have developmental or learning
disabilities or emotional or behavioral problems, due to abuse or neglect
or a lack of opportunity to be involved in a stable home or school life.
Many of the families as a whole are living in a "stigma" based
environment so only certain or no members of the family are aware of
the child's/mother's diagnoses. There is a lack of emotional and
physical support due to actual or perceived alienation. Many times
there is a misunderstanding of medical advice, drug regimen, lab
values, diagnoses and prognosis because the family, caregiver and/or
patient is not adequately educated. Some times family members are
infected or sick without knowing that they are infected with HIV or
AIDS.
MEDICATIONS AND ADHERENCE
Most children and adolescents are treated with combinations of
antiretroviral therapies (ART). Highly active antiretroviral therapy
(HAART) consists of combinations of drugs that attack the virus at
various stages of its life cycle (see Virology section above). The most
common combination consists of 2 nucleoside reverse transcriptase
inhibitors (NRTIs), along with a protease inhibitor (PIs). Others
include 2 NRTIs plus a non-nucleoside reverse transcriptase inhibitor
(NNRTI). Persons with more advanced disease or viral resistance may be
on more complex regimens involving multiple drug classes. Drug
therapies are generally guided by the drug resistance profile of the
patient's HIV, based on genotype testing, along with medication
tolerance.
While medication regimens can be as simple as 1 pill once a day, some
regimens call for multiple pills 2 or 3 times daily, some of which are
large and difficult to swallow, or have a bad taste. If the
medications are not taken as prescribed, resistance quickly develops
and the classes of drugs the patient has been using will become
ineffective in suppressing viral replication. Research has shown that
90% adherence is necessary to decrease the likelihood of development of
resistance. This level of adherence is very difficult to achieve with a great deal of the youth population.
Lack of medication or stigma may play a role in medication adherence
causing patients to hide, not take correctly, skip, or not take good
care of perishable medications because someone may see/question them. Some youth and family members may feel they do not need to take
medications because they have not been sick and have been sheltered
from their partner or parents' illness/death. Some individuals may not
have access to medications. In the United States, there are only a few
families that have a financial barrier to obtaining medications. Most
have full health coverage and the medications are covered with no
co-pay.
