With
early diagnosis, proper monitoring and care, most of the illnesses caused by HIV can be prevented. They
are much less frequent than they were before effective anti-HIV drugs became
available.
There are a number of infections and
illnesses that can develop in people who are living with HIV, particularly
those people who are not able to take anti-HIV drugs. Some of these life-threatening
infections are called
opportunistic
infections. These only occur if your immune system is quite
weakened (usually in the absence of
anti-HIV
drug therapy) and your body becomes vulnerable to infections that
would not affect you otherwise.
Co-infections are illnesses that can occur in people with normal
immune systems, but they can impact how you live with HIV.
Some types of cancers are thought to be more common in people
with HIV.
Increasingly, the distinction between these different types of
infections—life-threatening infections, co-infections and even some cancers—is
blurred, as some infections can fit all three categories (for example,
human
papillomavirus is a co-infection which can lead to cervical and anal
cancer).
Life-threatening
infections
These infections occur only when a
person’s immune system has been seriously weakened by HIV due to lack
of diagnosis and/or anti-HIV treatment. HIV attacks immune cells called CD4+
cells, which are needed for fighting off infections and some cancers. A normal
CD4+ cell count in an HIV-negative person is around 500 to 1,500 cells in each
cubic millimetre (mm
3) of blood. If your CD4+ cell count gets lower,
your immune system becomes unable to fight off a number of common viruses,
bacteria and parasites. These infections can then take hold. (They are
sometimes called
opportunistic
infections because they take advantage of your weakened immune
system.)
Life-threatening infections are uncommon now, since most people take
anti-HIV drugs, which controls their viral load, raises their CD4+ levels and
stabilizes and restores immune system function. This helps prevent
life-threatening infections caused by HIV.
The main danger nowadays is in not finding out you are HIV-positive until
your CD4+ cell counts are already so low that you are at risk or are already
sick with a life-threatening infection.
The more common life-threatening infections are listed in the accompanying
table. Some of these can still occur in people with relatively high CD4+ levels
but are more serious when the immune system is weakened.
Life-threatening infections include a lung infection called Pneumocystis
pneumonia (PCP), an eye infection caused by cytomegalovirus (CMV), a brain
infection called toxoplasmosis, and a generalized infection called
Mycobacterium avium complex (MAC). If it happens that you find out you have
HIV when
your CD4+ cell count is very low, there are drugs you can take to prevent these
infections. This is called prophylaxis
.
Co-infections
Hepatitis
These are infections that can occur even in people with HIV
who have adequate CD4+ levels—just as they can occur in people who do not have HIV. They
are called co-infections because you have them along with HIV. Co-infections
can complicate your HIV treatment and make living with HIV more difficult. HIV can also
complicate the treatment and diagnosis of a co-infection. Although they may
occur at normal CD4+ levels, the lower your CD4+ cell count is, the more of a
problem they can be.
Chronic hepatitis is an increasingly common
co-infection for many people with HIV. Hepatitis is
a liver condition usually caused by viruses called hepatitis A, hepatitis B or
hepatitis C. These viruses infect the liver and can cause jaundice (yellow skin
and eyes), dark urine, pale stool and severe fatigue. It is a good idea for
your doctor to check regularly for these infections. Hepatitis B and C are
transmitted by:
·
blood-to-blood contact through sharing drug-using
equipment, or personal care items like razors;
·
transfusion of blood and blood products before 1992
when the Canadian system started screening;
·
unprotected sexual intercourse;
·
being passed from mother to child during
childbirth.
Hepatitis A is another, usually less serious, viral
infection of the liver. Hepatitis A is spread through feces (shit), and you can
be infected by contaminated food (for instance, if someone handling your food
has hepatitis A and did not wash his or her hands). If you are exposed to
hepatitis A, it can make you quite sick for a few weeks, but your immune system
usually clears it. Hepatitis A very rarely causes permanent damage unless you
already have hepatitis B or C as well.
If infected with the hepatitis A or B virus, some
people get over the initial liver infection and develop immunity. This is much
less likely to happen in people with HIV who are co-infected with hepatitis C.
Without treatment, people can develop chronic hepatitis, remain infectious to others
and develop ongoing liver problems.
As described below, there are vaccinations that
will prevent you from getting hepatitis A and B infection. There is no
vaccination available for hepatitis C.
Effective antiviral treatments are available for
both hepatitis B and C infection. Treatment can cure hepatitis C and keep
hepatitis B under control. There are interactions between drugs to treat
hepatitis and HIV, so make sure you see a doctor with expertise in both
conditions.
Tuberculosis (TB)
TB
is a concern for people with HIV because it is so easily spread, especially in
places where people live close to each other, in poverty and without adequate
medical care.
TB
usually infects the lungs, but it can also affect the bones, brain and other
organs in your body. TB is spread through the air when someone with active TB
coughs or sneezes. Diagnosis of TB is done by skin tests, tests of your sputum
(phlegm) and chest X-rays. There are effective treatments for TB, but they need
to be taken every day for many months. Missing doses, or stopping before the
full treatment period is over, can cause the TB
infection to become drug-resistant and much more difficult to treat. People
with HIV with a history of previously treated TB may have it reactivate (come
back again) if their immune system weakens.
Herpes infections
Herpes is a family of viruses that includes:
·
Herpes
simplex, which causes cold sores on the mouth or painful sores on the
genitals.
·
Varicella-zoster, which initially causes chicken
pox and when reactivated causes painful sores called shingles anywhere on the
skin.
Herpes infections are common and are often
transmitted by physical contact and sex. Usually, the immune system keeps
herpes infection under control until something like stress or a high fever
brings the sores out in an outbreak lasting seven to 10 days, or longer. The
lower your CD4+ cell count, the more frequent outbreaks may be. They may
also last longer.
People with HIV with
extremely weak immune systems (CD4+ cell counts less than 100 cells/mm3) are at
risk for herpes infections all over the body (disseminated herpes) or in the
brain (herpes encephalitis). People with frequent herpes outbreaks (even with
normal CD4+ levels), or people at risk for more serious herpes infections, can
take antiviral drugs—usually valacyclovir or similar drugs—to keep the herpes
virus suppressed.
Fungal infections
Fungal or yeast infections can
happen whether you are HIV-positive or not. Women get vaginal yeast infections,
and men and women can get athlete’s foot or fungal infections on the skin or
nails. The more weakened your immune system is, the more this can be a problem.
Even people with moderate CD4+ cell
counts can get a fungal infection in the mouth or vagina called candidiasis or
thrush. Antifungal
creams, pills and vaginal suppositories are available to treat these
problems, and probiotic supplements or yoghurts with friendly bacteria may also
help. Watch your diet because the more sugar you eat, the more susceptible you
are to fungus, which loves sugar.
Sexually transmitted infections
Some of the infections discussed
above can be passed on in many ways, including through sex. Some other
infections, like chlamydia, gonorrhea and syphilis, and the
virus HPV,
are virtually always transmitted sexually.
Cancers
Cancer is the abnormal and uncontrolled growth of
cells in different parts of the body. These cancerous growths then destroy
healthy cells and cause serious illness. A normally functioning immune
system acts to suppress this abnormal growth of cells.
People with HIV
can become more vulnerable to certain types of cancer. Some of these cancers
occur only when the immune system is weakened. Other cancers seem to be more
common in people with HIV even when their immune system is relatively healthy.
Kaposi’s sarcoma
Kaposi’s sarcoma (KS), a
rare form of skin cancer, is caused by a member of the herpes virus family and
can be life-threatening. It causes purple lesions on the skin that looked
like bruises. Although slow growing, if it spreads to internal organs it could
lead to illness and death. In the early days of HIV, it was quite common in
people living with HIV. When HAART
was introduced, KS became uncommon and now only occurs in people with very weak
immune systems.
Non-Hodgkin’s
lymphoma
When the cells in the lymph nodes become
cancerous, this is called lymphoma. The non-Hodgkin’s type of lymphoma (NHL) is
more common in people with HIV. The symptoms of NHL may include persistently
swollen lymph glands, fevers, chills and sweats and weight loss. In the case of
central nervous system lymphoma, the symptoms are often headaches and seizures.
Diagnosis of lymphoma, like many cancers, is done
by biopsy where a sample of tissue from a swollen lymph node is examined under
the microscope for evidence of abnormal cells. In the event of central nervous
system lymphoma, the diagnosis is made by examining cerebrospinal fluid tapped
from the spine. Lymphoma is usually treated by chemotherapy,
where powerful anti-cancer drugs are injected into the vein on a regular basis,
and/or radiation therapy where high-powered X-rays are directed at the cancer
cells.
Cervical cancer
The cervix is the opening of the uterus (womb) inside a
woman’s vagina. Sometimes abnormal cells can start to grow on the cervix,
usually as a result of HPV
infection. Over time, these abnormal growths can become a pre-cancerous
condition called cervical dysplasia. If dysplasia is not found and treated, it
can become cancer.
To prevent this, all women should have
annual Pap tests to look for dysplasia from a small scraping of cells
from the cervix. Women with a history of genital
warts or cigarette smoking should have Pap exams more
frequently. If dysplasia is found, it is usually treated with a laser in a
procedure called colposcopy.
The HPV vaccine will
protect women from some, but not all, strains of HPV and so it is hoped it will
prevent some cases of cervical cancer. However, this vaccine is effective only
if it is given before women have been exposed to the HPV strains the vaccine
targets.
Anal cancer
Cancer in the anal canal of men and
women is similar to cervical cancer. It is also usually caused by
infection with HPV and, like cervical
cancer, develops over time from dysplasia to cancer. Risk factors
include a history of anal sex and/or genital warts. Both men and women with HIV
are thought to be more vulnerable to this form of cancer.
Other cancers
There are many other forms of
cancers that people with HIV
are thought to be at slightly higher risk for, even without immune suppression.
These include Hodgkin’s lymphoma, lung cancer, skin cancer, vaginal cancer in
women and testicular and prostate cancer in men. Fortunately, these cancers are
not common and can often be successfully treated if they do occur in people
with HIV who maintain healthy immune systems with effective anti-HIV
drugs.
