Saturday, September 24, 2005

Health Headlines - September 24

Thalassemias

Thalassemias is the name for the group of genetic blood diseases which vary widely in severity.

As frightening as thalassemias can be, the outlook is encouraging. In the past 20 years, new therapies have greatly improved the quality of life and life expectancy in kids who are diagnosed with this disease.

What Is Thalassemia?
Thalassemia is a genetic disorder that involves the decreased and defective production of hemoglobin, a molecule that's found inside all red blood cells and is necessary to transport oxygen throughout the body.

Hemoglobin contains two different kinds of protein chains named alpha and beta chains. Any deficiency in these chains causes abnormalities in the formation, size, and shape of red blood cells.

There are two types of thalassemia: alpha-thalassemia and beta-thalassemia. Their names describe which part of the hemoglobin molecule that is effected, the alpha or the beta chain.

Thalassemia can cause ineffective production of red blood cells, and the destruction of red blood cells. As a result, people with thalassemia often have a reduced number of red blood cells in the bloodstream, a condition called anemia, which can affect the transportation of oxygen to the body tissues that need it. In addition, thalassemia can cause red blood cells to be smaller than normal, or the amount of hemoglobin in the red blood cells to be below normal levels.

Kids who have with different forms of thalassemia have different kinds of health problems resulting from the disorder. Some children only have mild anemia with little or no effects, while others require frequent serious medical treatment.

What Causes Thalassemia?
Thalassemia is always inherited, passed on from parents to children through their genes. A child cannot develop the disease unless both parents carry the thalassemia gene.

If only one parent passes the gene for thalassemia on to the child, then the child is said to have thalassemia trait. Thalassemia trait will not develop into the full-blown disease, and no medical treatment is necessary. Many families have thalassemia carriers, but the trait often goes undiagnosed because the trait produces no or few symptoms. Frequently, thalassemia is not diagnosed in a family until a baby is born with the disease. So if someone in your family carries the gene, it's a good idea to have genetic counseling when you're thinking of having children.

At one time it was believed that the disease affected only people of Italian or Greek descent. It is now known that in addition to people living in areas on the Mediterranean Sea (Italy, Greece, and Turkey), many people with thalassemia also come from or are descended from Africa, Malaysia, China, and many parts of Southeast Asia.

Because of a recent pattern of migration from Southeast Asia, there has been an increase in the past decade of thalassemia in North America. Testing for thalassemia is generally recommended for anyone from Southeast Asia with unexplained anemia. If your healthcare providers determine that your child is at risk for being affected by thalassemia, there are prenatal tests that you can have to find out if your unborn child is affected by the disease.

Alpha-Thalassemia
Children with alpha-thalassemia trait do not have thalassemia disease. A specific blood test called a hemoglobin electrophoresis is used to screen for alpha-thalassemia trait and can be done in infancy. But often, diagnosis of alpha thalassemia is done only after other conditions are ruled out, after the parents are screened. The disease can be harder to detect in older children and adults.

Kids who have the alpha-thalassemia trait usually have no significant health problems, with the exception of possibly being mildly anemic. The anemia can cause slight fatigue.

The fatigue resulting from alpha-thalassemia trait is often mistaken for an iron deficiency.
Other cases of alpha-thalassemia resemble another form of the disorder, called beta-thalassemia intermedia (see next section). People with this form of alpha-thalassemia may require occasional blood transfusions during times of physical stress, like fevers or other illnesses, or at times when the anemia becomes severe enough to cause symptoms such as fatigue.

The most severe form of the disorder is called alpha-thalassemia major. This type is extremely rare, and women carrying fetuses with this form of thalassemia have a high incidence of miscarriage because the fetuses cannot survive.

Beta-Thalassemia
Beta-thalassemia, the most common form of the disorder seen in the United States, is grouped into three categories: beta-thalassemia minor (trait), intermedia, and major (Cooley's anemia). A person who carries the beta-thalassemia gene has a 25% (1 in 4) chance of having a child with the disease if his or her partner also carries the trait.

Beta-Thalassemia Minor (trait)
Beta-thalassemia minor often goes undiagnosed because kids with the condition have no real symptoms other than mild anemia. It is often suspected based on routine blood tests such as a complete blood count (CBC) and can be confirmed with a hemoglobin electrophoresis. No treatment is usually needed.

As with alpha-thalassemia trait, the anemia associated with this condition may be misdiagnosed as an iron deficiency.

Beta-Thalassemia Intermedia
Children with beta-thalassemia intermedia have varying effects from the disease - mild anemia might be their only symptom or they might require regular blood transfusions.

The most common complaint is fatigue or shortness of breath. Some children also experience heart palpitations, also due to the anemia, and mild jaundice, which is caused by the destruction of abnormal red blood cells that result from the disease. The liver and spleen may be enlarged, which can feel uncomfortable for a child. Severe anemia can also affect a child's growth.

Another symptom of beta-thalassemia intermedia can be bone abnormalities. Because the bone marrow is working overtime to make more red blood cells to counteract the anemia, children can experience enlargement of their cheek bones, foreheads, and other bones. Gallstones are also a frequent complication of thalassemia because of abnormalities in bile production that involve the liver and the gallbladder.

Some children with beta thalassemia intermedia may require a blood transfusion only occasionally. They will always have anemia, but may not need transfusions except during illness, medical complications, or later on during pregnancy.

Other children with this form of the disease require blood transfusions on a regular basis. In these kids, low or falling hemoglobin levels greatly reduce the blood's ability to carry oxygen to the body, resulting in extreme fatigue, poor growth, and facial abnormalities. Regular transfusions can help alleviate these problems. Sometimes, kids who have this form of the disease have their spleens removed.

Beta-thalassemia intermedia is often diagnosed in the first year of a child's life. Doctors may be prompted to test for it when a child has chronic anemia, or a family history of the condition. As long as it is diagnosed while the child is still doing well and has not experienced any serious complications, the disorder can be successfully treated and managed.

Beta-thalassemia Major
Beta-thalassemia major, which is also called Cooley's anemia, is a severe condition in which regular blood transfusions are necessary for the child to survive.

Although multiple lifelong transfusions save lives, they also cause a serious side effect: an overload of iron in the bodies of thalassemia patients. Over time, people with thalassemia accumulate deposits of iron in their bodies, especially in the liver, heart, and endocrine (hormone-producing) glands. The deposits eventually can affect the normal functioning of the heart, and liver, in addition to delaying growth and sexual maturation.

To minimize iron deposits in the body, people affected by the disease must undergo chelation (iron-removing) therapy for up to 12 hours a day with subcutaneous (under the skin) doses of the iron-binding agent. Researchers are working to develop an iron chelator, which can be given by mouth, but currently, none is available.

Chelation therapy is typically given 5 to 7 days a week and has been proven to prevent liver and heart damage from iron overload, allow for normal growth and sexual development in children with thalassemia, and increase life span. Iron concentrations in the body are monitored every few months. Sometimes liver biopsies are needed to get a more accurate picture of the body's iron load.

There are side effects of the chelation drug, which is called desferrioxamine, which can include visual impairment and hearing loss. Any children who receive chelation therapy are usually screened on a regular basis for such side effects.

Other risks associated with chronic blood transfusions for thalassemia major include blood-borne diseases like hepatitis B and C. Blood banks can usually screen for such infections, in addition to rarer infections such as HIV. In addition, kids who have many transfusons can develop allergic reactions that can prevent further transfusions and cause serious illnesses.
For kids and teens with thalassemia, adolescence can be a difficult time, particularly because of the amount of time required for transfusions and chelation therapy.

Recently, some children have successfully undergone bone marrow transplants to treat thalassemia major; however, this is considered only in cases of severely disabling thalassemia disease. There is considerable risk to bone marrow transplants: the procedure involves the destruction of all of the blood-forming cells in the child's bone marrow and repopulating the marrow space with donor cells that must match perfectly (the closest match is usually from a sibling). The procedure is usually done in children younger than 16 years of age who have no existing evidence of liver scarring or serious liver disease. Results have been highly encouraging so far, with disease-free survival in most patients.

Blood-forming stem cells taken from umbilical cord blood have also been successfully transplanted, and research using this technique is expected to increase. Currently bone marrow treatment is the only known cure for the disease.

Talking to Your Child's Doctor
If you know the thalassemia trait exists in your family, it's important to meet with your child's doctor, particularly if you notice any of the symptoms of thalassemia major - anemia, listlessness, or bone abnormalities - in your child. If you are thinking of having children, particularly if you have any thalassemia in your family, it's a good idea to speak with a genetic counselor to determine your risk of passing on the disease to any future children.


Sepsis

Sepsis is a serious but rare infection that is usually caused by bacteria. It occurs when bacteria, which can originate in a child's lungs, intestines, urinary tract, or gallbladder, make toxins that cause the body's immune system to attack the body's own organs and tissues.

Sepsis can be frightening because if it is untreated, it can lead to serious complications that affect a child's kidneys, lungs, brain, and hearing. But by learning to recognize the symptoms, you can help your child get treatment and fully recover.

Sepsis can affect a person of any age, but it is more prevalent in young infants whose immune systems have not developed enough to fight off overwhelming infections and people whose immune systems are compromised from conditions such as HIV.

If your infant has a rectal temperature of 100.4 degrees Fahrenheit (38 degrees Celsius)
seems lethargic, uninterested in eating, or seems to be having difficulty breathing, it's a good idea to call your child's doctor. In an older child, the symptoms of sepsis may include a fever (an oral temperature at or above 99.5 degrees Fahrenheit [37.5 degrees Celsius]); your child may also seem lethargic, irritable, and may complain that his or her heart feels like it's racing.

If your child's temperature is normal, but you're still concerned, it's a good idea to call the doctor.

What Is Sepsis?
Sepsis occurs when the body's normal reaction to inflammation or a bacterial infection goes into overdrive. With sepsis, the bacteria create a toxin that causes a widespread inflammation of the body's organs and causes rapid changes in a person's body temperature, blood pressure, and dysfunction in the lung and other organs.

Babies under the age of 2 months are more susceptible to sepsis because their immune systems have not yet developed enough to fight off some serious infections. It is also more prevalent in people of all ages whose immune systems are compromised by chronic illnesses and conditions like HIV.

Signs and Symptoms of Sepsis
Sepsis in newborns produces few concrete symptoms, though symptoms can vary widely between from child to child. Frequently, these babies suddenly aren't feeling well or "just don't look right" to their caretakers.

Some of the more common signs or symptoms of sepsis in newborns and young infants include:

disinterest or difficulty in feeding
fever (above 100.4 degrees Fahrenheit [38 degrees Celsius] rectally) or sometimes low, unstable temperatures
irritability or increased crankiness
lethargy (not interacting and listless)
decreased tone (floppiness)
changes in heart rate - either faster than normal (early sepsis) or significantly slower than usual (late sepsis, usually associated with shock)
breathing very quickly or difficulty breathing
periods where the baby seems to stop breathing for more than 10 seconds (apnea)
jaundice
Older children who have sepsis might have a fever (an oral temperature above 99.5 degrees Fahrenheit [37.5 degrees Celsius]), vomit, and complain of feeling like their hearts are racing. A child with sepsis may have started with an infection such as cellulitis that seems to be spreading and getting worse, not better.

What Causes Sepsis?
Bacteria are almost always the cause of sepsis in newborns and infants.

Bacteria such as E. coli, Listeria monocytogenes, Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae type b, Salmonella, and Group B streptococcus (GBS) are the more common culprits in sepsis in newborns and infants younger than 3 months.

Premature babies receiving neonatal intensive care are particularly susceptible to sepsis because their immune systems are even more underdeveloped than other babies, and they typically undergo invasive procedures involving long-term intravenous (IV) lines, multiple catheters, and need to breathe through a tube attached to a ventilator. The incisions a young infant gets for catheters or other tubes can provide a path for bacteria, which normally live on the skin's surface, to get inside the baby's body and cause the infection.

In many cases of sepsis in new babies, bacteria enter the baby's body from the mother during pregnancy, labor, or delivery. Some pregnancy complications that can increase the risk of sepsis for a newborn include:

bleeding
maternal fever
an infection in the uterus or placenta
premature rupture of the amniotic sac (before 37 weeks of gestation)
rupture of the amniotic sac very early in labor (18 hours or more before delivery)
a long, difficult delivery
Some bacteria - GBS in particular - can be acquired by the newborn as the child is being delivered. At least one out of every five pregnant women carries the bacterium for Group B streptococcus in her vagina or rectum, where it can be passed from mother to child during delivery.

Diagnosing and Treating Sepsis
Because symptoms of sepsis can be vague in infants, laboratory tests play a crucial role in confirming or ruling out sepsis. These lab tests may include:

Blood tests (including red and white blood cell counts) and blood cultures may be taken to determine whether bacteria are present in the blood.
Urine is usually collected by inserting a sterile catheter into the baby's bladder through the urethra for a few seconds to remove urine; this will be examined under a microscope and cultured to check for the presence of bacteria.
A lumbar puncture (spinal tap) may be performed, depending on the baby's age and overall appearance. A sample of cerebrospinal fluid will be tested and cultured to determine if the baby has possible meningitis.
X-rays, especially of the chest (to make sure there isn't pneumonia), are sometimes taken.
If the baby has any kind of medical tubes running into his or her body (such as IV tubes, catheters, or shunts), the fluids inside those tubes may be tested for signs of infection as well.
Sepsis, or even suspected cases of sepsis in infants, is treated in the hospital, where doctors can closely watch the infection and administer strong antibiotics intravenously to fight the infection.

Typically, doctors start infants with sepsis on antibiotics right away - even before the diagnosis is confirmed. If more symptoms of sepsis begin to appear, they usually start them on IV fluids to keep them hydrated, blood pressure medication to keep their hearts working properly, and respirators to help them breathe.

Can Sepsis Be Prevented?
Although there's no way to prevent all types of sepsis, some cases can be avoided, namely the transmission of Group B streptococcus bacteria from mother to child during childbirth. Pregnant women can have a simple swab test during the 35th and 37th weeks of pregnancy and again just before the birth to determine if they carry the GBS bacteria.

If a woman tests positive for GBS, she can receive intravenous antibiotics during labor.

Women are at higher risk of carrying GBS if they have a fever during labor, if the amniotic sac ruptures prematurely, if they have prolonged labor, or if they had other children with sepsis or other diseases triggered by GBS, such as pneumonia or meningitis. A woman with one of these risk factors can receive intravenous antibiotics to lower her risk of transmitting the bacteria to her child.

Immunizations routinely given to infants today include vaccinations against certain strains of pneumococcus and Haemophilus influenzae type b that can cause sepsis or occult bacteremia, an infection of the blood.

When to Call Your Child's Doctor
Because the symptoms of sepsis can be very difficult to identify in newborns and young infants, it's a good idea to call your child's doctor or seek emergency medical care if your baby shows any of the following symptoms:

difficulty or continued disinterest in feeding
fever (100.4 degrees Fahrenheit [38 degrees Celsius] and above rectal temperature) in newborns and young infants
labored or unusual breathing
change in skin color (paler than usual or mildly bluish)
listlessness or lethargy
change in the sound of the baby's cry or excessive crying
change in baby's muscle tone - either seeming too stiff or especially floppy
a slower or faster heart rate than usual
bulging or fullness of the "soft spot" on the baby's head
any type of behavior or appearance that concerns you
These signs and symptoms don't necessarily mean your baby has sepsis, but infants who are younger than 3 months should be checked out immediately to ensure that nothing else is wrong.

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