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Thursday, February 22, 2007

The Complete Blood Count (CBC)

The complete blood count (CBC) is a very common blood test. It evaluates the three major types of cells in blood: red blood cells, white blood cells, and platelets.

Doctors often order a CBC for a child to check for anemia, infections, or other health problems.

How Is a CBC Test Taken?

It doesn't take much blood to perform a CBC. A health professional may take it by sticking a child's heel or finger with a small, sharp surgical instrument. The blood for a CBC also can be taken from a vein. After the skin surface is cleaned, a needle is inserted into a vein (usually in the arm) and blood is withdrawn.

Either method of collecting a sample is only temporarily uncomfortable and can feel like a gentle pinprick. The sample is collected in special tubes and then processed by a machine, usually referred to as a hematology analyzer.

CBC results can be available in minutes in an emergency, but more commonly come after a few hours or the next day.

Parts of the CBC

Red Blood Cell Count, Hemoglobin, and MCV

Three tests - measuring red blood cell (RBC) count, hemoglobin, and mean (red) cell volume (MCV) - provide information about the red blood cells, which carry oxygen from the lungs to the rest of the body. These tests are usually done to test for anemia, a common condition that occurs when there aren't enough red blood cells.

  • The red blood cell count is a measure of the number of RBCs in the body.
  • Hemoglobin is the oxygen-carrying protein in red blood cells. RBCs carry oxygen to all parts of the body.
  • MCV measures the average size of the red blood cells.

Other factors analyzed include the hematocrit (HCT), which is the percentage of red blood cells in the blood sample. If a child has anemia, the results for RBC, hemoglobin, and hematocrit will all be low.

Many things can cause anemia. Sometimes it occurs because not enough RBCs are being made and other times it's because the cells are either being destroyed or lost through bleeding. If a CBC points to anemia, your child's doctor will likely order other lab tests to determine what's causing it and how to treat it.

White Blood Cell Differential Count

Also part of the CBC is the blood differential test that measures the relative numbers of white blood cells (WBCs) in the blood. WBCs (also called leukocytes) help the body fight infection. These cells are bigger than red blood cells, and there are far fewer of them in the bloodstream. An abnormal white blood cell count may indicate that there is an infection, inflammation, or other stress in the body. For example, a bacterial infection can cause the WBC count to increase or decrease dramatically.

There are five types of white blood cells: neutrophils, lymphocytes, eosinophils, basophils, and monocytes. Each has a different job.

The two major types of WBCs are neutrophils and lymphocytes. Neutrophils play a key role in the body's defense against invading bacteria by destroying invading organisms. Someone with insufficient neutrophils is at risk for developing serious infections. Lymphocytes produce antibodies, specific proteins that attack and help destroy specific germs. They are especially important in fighting viral infections, like colds and flu. People with advanced HIV can have low lymphocyte counts, increasing their risk for developing certain infections.

Eosinophils and basophils in the blood may be increased in allergic conditions. Monocytes, the largest white blood cells in the bloodstream, remove dead cells and organisms from the blood.

The Platelet Count

Platelets are the smallest blood cells. They play an important role in blood clotting and the prevention of bleeding. When a blood vessel is damaged or cut, platelets clump together and plug up the hole until the blood clots. If the platelet count is too low, a person can be in danger of bleeding in any part of the body.

Source: www.kidshealth.org

Pregnancy -- Travel During Pregnancy

Medical opinion is often sought as to whether overseas travel is safe during pregnancy, often in the hope of receiving reassurance that the risks are small.

While most pregnant women will enjoy a trouble-free journey, a pregnancy can never be guaranteed to be medically uneventful. Should medical treatment be required, there are likely to be advantages in being at home. Concerns overseas include the availability of medical expertise, possible lack of sterile equipment and blood, the absence of a doctor familiar with the individual history, language difficulties, and cost.

Some infectious diseases (eg malaria - see below) can be more severe during pregnancy and the wisdom of travel to infected areas should be questioned.

Malaria chemoprophylaxis

Malaria in pregnancy is usually a more severe disease which can result in abortion or stillbirth and complications in the mother.

All pregnant woman travelling to malarious regions should use chemoprophylaxis. Chloroquine and proguanil have a proven safety record in pregnancy. Mefloquine is not routinely used in pregnancy. The product data sheet states that in the absence of clinical experience, prophylactic use during pregnancy should be avoided as a matter of principle. Recent studies suggest that it is safe in the second and third trimesters. So, where a pregnant traveller cannot be dissuaded from visiting areas with a significant risk of highly chloroquine resistant P.falciparum malaria, it can be used cautiously in the second and third trimesters. Ongoing studies suggest it may also be safe in the first trimester. All fertile women using mefloquine should use reliable contraceptives, until three months after the last dose.

As always, chemoprophylactic drugs should be used in combination with measures to reduce mosquito bites. However, DEET-containing repellents should be used sparingly.

Travel Immunisations

All vaccines should be avoided as far as possible in pregnancy because of the theoretical risk of damage to the developing fetus. Published data are generally not available.

For inactivated vaccines, the threat of the disease should be weighed against any risk of the vaccine. If post-exposure rabies immunisation is required, human diploid cell rabies vaccine should be advised.

Live vaccines should especially be avoided if possible. If a yellow fever vaccination certificate is required purely for entry purposes, a certificate of exemption will normally suffice. If the vaccine is inadvertently given to a pregnant woman, she should be reassured that neither yellow fever, nor oral polio or rubella vaccines, have been shown to cause fetal damage. If the danger of infection cannot be avoided, these vaccines could be administered. BCG is similarly best avoided during pregnancy although there is no evidence of harm.

Where the decision has been made to administer a vaccine, it should ideally be delayed until the second or third trimester of pregnancy.

Flying

Where travel is planned during pregnancy, 18-24 weeks is probably the ideal time. Airlines usually allow travel up to the 36th week, but after the 28th week a doctor's letter may be required stating that the pregnancy is normal, the expected delivery date, and that the doctor is happy for the woman to fly. The policy of individual airlines should be checked.

Travel Tips

Here are some helpful hints that apply to any mode of travel you choose:

  • See your doctor before you plan to travel late in pregnancy. You don't want to go into labor far from home.
  • Take a copy of your health record with you if you'll be far from home.
  • In case of emergency, ask your doctor for the name and phone number of a doctor where you are going to travel.
  • Keep your travel plans easy to change. Problems can come up at any time. Buy travel insurance to cover tickets and deposits that can't be refunded.
  • While you are en route, try to walk around about every hour. Stretching your legs will lessen the risk of blood clots and make you more comfortable. It also will decrease the amount of swelling in your ankles and feet.
  • Wear comfortable shoes and clothing. You may want to wear support or pressure stockings.
  • Carry some light snacks with you to help prevent nausea.
  • Take time to eat. A balanced and healthy diet during your trip will boost your energy and keep you feeling good. Be sure to get plenty of fiber to ease constipation, a common travel (and pregnancy) problem.
  • Drink plenty of fluids to help prevent urinary tract infections. Take a bottle of water or some juice with you.
  • Don't take any medication not prescribed for you. Don't take any medicine—including motion-sickness pills, laxatives, diarrhea remedies, or sleeping pills—before checking with your doctor.
  • Get plenty of sleep, and rest often.
  • Stretch your back muscles from time to time.


Travel Medical Insurance

Insurance policies should be checked for exclusions.

Saturday, February 17, 2007

Sleep Problems -- Ritual Before Get Better Night’s Sleep

The average total nightly sleep time is 7.5 to 8 hours. Healthy adults can require anywhere from 4 to 10 hours of sleep. Many times, simple home treatment can help you get the sleep you need.

The Activities Before Go to Sleep

The following are some activities can promote good sleep habits:

  • Set a bedtime and time to get up, and stick to them, even on weekends. This will help your body get used to a regular sleep time.
  • Exercise during the day. Avoid strenuous exercise within 2 hours of bedtime.
  • Wind down toward the end of the day. Don't take on problem-solving conversations or challenging activities in the evening.
  • Take a warm bath before bed.
  • Keep your bedroom dark, cool, and quiet.
  • Remove distractions, such as a clock, telephone, or radio, from your bedroom.
  • Use a humidifier or "white noise" machine to block out background noise in your bedroom throughout the night.
  • Try using a sleep mask and ear plugs at night.
  • If you take medication that may be stimulating, such as antihistamines, decongestants, or asthma medications, take them as long before bedtime as possible.
  • Reserve the bedroom for sleeping and sexual activities so that you come to associate it with sleep. Go to another room to read, watch television, or eat.
  • After getting into bed, make a conscious effort to let your muscles relax. Imagine yourself in a peaceful, pleasant scene.

If you still cannot get to sleep, try the following:

  • When you are awake after 15 or 20 minutes, get up and read in dim light or do a boring task until you feel drowsy.
  • Don't lie in bed and think about how much sleep you're missing or watch TV.

Don’t Do This Activities

Avoid activities that might keep you from a good night's sleep:

  • Do not take naps during the day, especially in the evening.
  • Do not drink or eat caffeine after 3:00 p.m. This includes coffee, tea, cola drinks, and chocolate.
  • Do not smoke or use other tobacco products. Nicotine can disrupt sleep and reduce total sleep time. Smokers report more daytime sleepiness and minor accidents than do nonsmokers, especially in younger age groups.
  • Avoid drinking alcohol. It may make you sleepy but also will probably wake you up after a short time.

Try a nonprescription medication, such as Nytol, Sleep-Eze, or Sominex. Use nonprescription medications wisely since they can cause daytime confusion, memory loss, and dizziness. Continued use of sleeping pills may actually increase your sleeplessness (rebound insomnia).

Melatonin is a popular herbal remedy for sleep problems. Experts disagree about its usefulness for sleep problems. Before using any treatment, it is important to consider the risks and benefits of the treatment.

If you have several nights of difficulty sleeping, review all of your prescription and nonprescription medications with your health professional or pharmacist to determine whether the medications you take could be the cause of your sleep problem.

Symptoms to Watch For During Home Treatment

  • Your sleep problem becomes worse.
  • Your sleep problem lasts longer than 4 weeks.
  • Your symptoms become more severe or frequent.

Sleep Problems -- Age 12 and Older

From Healthwise -- http://health.msn.com/


Everyone has a "bad night" once in a while. Dogs barking, the wind howling, or overeating may make it difficult to sleep. It is estimated that 35% of adults have occasional sleep problems, which can have many causes.

Insomnia

The medical term for difficulty falling asleep or staying asleep is insomnia. Insomnia can include:

  • Difficulty getting to sleep (taking more than 45 minutes to fall asleep).
  • Frequent awakenings with inability to fall back to sleep.
  • Early morning awakening.
  • Feeling very tired after a night of sleep.

However, insomnia usually is not a problem unless it makes you feel tired during the day. If you are less sleepy at night or wake up early but still feel rested and alert, there usually is little need to worry. Fortunately, home treatment measures successfully relieve occasional insomnia.

Occasional insomnia may be caused by noise, extreme temperatures, jet lag, changes in your sleep environment, or a change in your sleep pattern, such as shift work. Insomnia may also be caused by temporary or situational life stresses, such as a traumatic event or an impending deadline. Your insomnia is likely to disappear when the cause of your sleep problem goes away.

  • Short-term insomnia may last from a few nights to a few weeks and be caused by worry over a stressful situation.
  • Long-term insomnia, which may last months or even years, may be caused by:
    • Advancing age. Insomnia occurs more frequently in adults older than age 60.
    • Mental health problems, such as anxiety, depression, or mania.
    • Medications. Many prescription and nonprescription medications can cause sleep problems.
    • Chronic pain, which often develops after a major injury or illness, such as shingles or back problems, or after a limb has been amputated (phantom limb pain).
    • Other physical problems, such as asthma, coronary artery disease, or chronic obstructive pulmonary disease (COPD).
    • Alcohol and illegal drug use or withdrawal.

Sleep apnea

Sleep apnea is one of several sleep disorders. Sleep apnea refers to repeated episodes of not breathing during sleep for at least 10 seconds (apneic episodes). It usually is caused by a blockage in the nose, mouth, or throat (upper airways). When airflow through the nose and mouth is blocked, breathing may stop for 10 seconds or longer. People who have sleep apnea usually snore loudly and are very tired during the day. It can affect children and adults.

Narcolepsy

Narcolepsy is a sleep disorder that has distinct symptoms, including:

  • Sudden sleep attacks, which may occur during any type of activity at any time of day. You may fall asleep while engaged in an activity such as eating dinner, driving the car, or carrying on a conversation. These sleep attacks can occur several times a day and may last from a few minutes to several hours.
  • Sudden, brief periods of muscle weakness while you are awake (cataplexy). This weakness may affect specific muscle groups or may affect the entire body. Cataplexy is often brought on by strong emotional reactions, such as laughing or crying.
  • Hallucinations just before a sleep attack.
  • Brief loss of the ability to move when you are falling asleep or just waking up (sleep paralysis).

Parasomnias

Parasomnias are undesirable physical activities that occur during sleep involving skeletal muscle activity, nervous system changes, or both. Night terrors and sleepwalking are two types of parasomnias. Sleep can be difficult for people who experience parasomnias. While “asleep,” a person with parasomnia may walk, scream, rearrange furniture, eat odd foods, or wield a weapon.

Parasomnia can cause odd, distressing, and sometimes dangerous nighttime activities. These disorders have medically explainable causes and usually are treatable.

Restless legs syndrome

Restless legs syndrome (RLS) is a condition that produces an intense feeling of discomfort, aching, or twitching deep inside the legs. Jerking movements may affect the toes, ankles, knees, and hips. Moving the legs or walking around usually relieves the discomfort temporarily.

The exact cause of restless legs syndrome is unknown. The symptoms of restless legs syndrome most often occur while a person is asleep or is trying to fall asleep. The twitching or jerking leg movements may wake the person up, causing insomnia, unrestful sleep, and daytime sleepiness.

When a sleep problem or lack of time keeps you from getting a good night's sleep, excessive daytime sleepiness may occur. While almost everyone experiences daytime sleepiness from time to time, it can have serious consequences such as motor vehicle accidents, poor work or school performance, and work-related accidents.

Sleep problems may be a symptom of a medical or mental health problem. It is important to consider whether a medical or mental health problem is causing you to sleep poorly. Treating a long-term sleep problem without looking for the cause may hide the real reason for your poor sleep.

Review the Emergencies and Check Your Symptoms sections to determine if and when you need to see a health professional.

Author content by: Sydney Youngerman-Cole, RN, BSN, RNC
Medical Review: William M. Green, MD - Emergency Medicine Malin K. Clark, MD, FRCPC - Psychiatry

Friday, February 16, 2007

Taking Temperature

Normal temperature

A normal temperature is about 37oC (98oF) when taken orally (by mouth). Temperatures taken rectally (by rectum) usually run 0.5oC higher than those taken orally. So a normal temperature is about 37.5oC (99.5oF) when taken rectally. But temperatures may vary during the day, even in healthy children. Many doctors define a fever as an oral temperature above 37.8oC (100oF) or a rectal temperature above 38.0oC (101oF) or an axillary (by ear) temperature above 37.2oC (99oF) (ear temperatures are not accurate in children under 6 months of age and often not recommended in children less than 1 to 2 years of age).

The best way to take child's temperature

You may think you can tell if your child has a fever by touching his or her forehead. It may alert you to a fever, but this isn't an accurate way to tell. Fever strips, which are placed on the child's forehead, are also not accurate.

The best ways to take your child's temperature are orally, rectally, by placing the bulb of the thermometer under the arm (axillary temperature) or using an ear thermometer. For children under 2, you can check by doing an axillary temperature and do a rectal temperature if there is a fever, in order to get an accurate measurement.

Some tips on taking child's temperature:

  • If you are using a mercury thermometer, the mercury of the thermometer should be below 35oC (95oF) before taking a temperature. You can run cool water over the thermometer to lower the reading. Some thermometers must be shaken to lower the reading.
  • Don't bundle your baby or child up too tightly before taking the temperature.
  • Never leave your child alone while taking the temperature.
  • Be sure you use the right thermometer. Rectal thermometers are thicker than oral thermometers (the bulb is fatter). Digital thermometers are usually used in the mouth or under the arm.
  • If you're taking your child's temperature orally, place the end of the thermometer under the tongue and leave it there for two minutes. Don't let your child bite on the thermometer. The child must be old enough to cooperate and often this method is used in children over 4 to 5 years of age. Digital thermometers may beep when they are ready to be read.
  • If you're taking your child's temperature rectally, coat the tip of the thermometer with petroleum jelly (Vaseline) and insert it half an inch into the rectum. Hold the thermometer still for two minutes. Never let go of the thermometer. This method often works best with infants. Some doctors prefer the axillary method for safety reasons.
  • Axillary temperatures are not always accurate but this is a safe way to take the temperature of toddlers and children under 4 years of age. Place the bulb of a glass thermometer in the child's armpit and hold the arm against the child's body so that the bulb is covered. Keep the bulb in place for at least 3 minutes.
  • Ear temperatures - Uses a special thermometer that quickly takes the temperature from the eardrum (tympanic membrane). These are not accurate in infants and the machines can be expensive.
  • After you're done using the thermometer, wash it in cool, soapy water or according to the manufacturer's directions.

Saturday, February 10, 2007

Chocolates -- Healthy Chocolate


Let's face it. We're all going to eat chocolate. But you don't have to feel guilty! Chocolate is actually good for you...it's all the things added to it that are the problem. Here's how you can choose delicious healthy chocolates to enjoy anytime.

Health Benefits

The gift of chocolate to a beloved as a token of love is more than just tradition. Naturally-occurring compounds in chocolate produce that mild euphoria of being in love and contribute to enjoyable interpersonal relations by elevating mood and enhancing sensory perception.

Beyond good feelings, chocolate benefits the body in many ways. In moderation, chocolate can contribute to heart health, help you live longer, suppress a chronic cough, and add needed magnesium to your diet. Chocolate even contains a high level of chromium, which can help control blood sugar.

Health Problems

While chocolate itself is fine to eat, there are some substances present in chocolate products that you should watch out for.

Most chocolate products contain tremendous amounts of refined white sugar, which is harmful to health in many ways.

Chocolate may also contain pesticides. The EPA allows various levels of pesticide residue to be present in cocoa powder, and the FDA Total Diet Study found them in many chocolate products.

Many chocolates also contain the toxic metals cadminum and lead. "Significant levels" of these metals were found in 68% of the common chocolate products tested. There is no safe level for lead, and it is particularly harmful to children.

Healthy Chocolate Choices

Here are some guidelines for choosing the healthiest chocolates.

1. Choose chocolates with the least amount of refined white sugar or other sweetener. Dark "bittersweet" chocolates with a high percentage of cocoa solids (usually the label will state the exact percentage) have less sugar than semisweet or milk chocolate and also have the greatest health benefits. Keep in mind that flavor additions, such as dried fruits and candied ginger may also add sugar to the chocolate.

2. Choose chocolates sweetened with evaporated cane juice or barley malt. If the evaporated cane juice used is the unprocessed whole juice of the cane, it acts in the body like a whole food and doesn't give a sugar rush. Barley malt is also a slow-release sweetener, noted on the label as "grain-sweetened."

3. Choose organic chocolates. Certified organic chocolate ensures there are no harmful pesticide residues.

4. Make your own chocolates. It's easy to make many chocolate delights yourself, with the exact ingredients you want. Start with unsweetened cocoa powder or baking chocolate and be creative!

5. Choose quality over quantity. If you are going to eat chocolate, eat really good chocolate. Then, for maximum enjoyment, give the taste of the chocolate your full attention, eat it at a time when you are not famished or overly full, and allow the chocolate to melt in your mouth to make the experience last.

So go ahead and enjoy chocolate, in moderation, as part of an otherwise healthy diet. Anyway, find some popular quotes about chocolate in here.

Source: http://ezinearticles.com

Friday, February 9, 2007

Say It with Flower


Flower meanings and symbolisation were a key element to flower choice many years ago. Sending flowers must be one of the most special ways to brighten up someones day. Choose the flower meaning that is closest to the message you're trying to convey and let your loved ones know that you wanted their gift to be extra-special. Here are a few of the more traditional ones.

Thursday, February 8, 2007

Dengue Hemorrhagic Fever (DHF) -- The Tests

Tests may include the following:
  • Hematocrit
  • Platelet count
  • Electrolytes
  • Coagulation studies
  • Liver enzymes
  • Blood gases
  • Tourniquet test (causes petechiae below the tourniquet)
  • X-ray of the chest (may demonstrate pleural effusion)
  • Serologic studies (demonstrate antibodies to Dengue viruses)
  • Serum studies from samples taken during acute illness and convalescence (increase in titer to Dengue antigen).

Hematocrit (HTC)

The hematocrit is the percent of whole blood that is composed of red blood cells. The hematocrit is a measure of both the number of red blood cells and the size of red blood cells.

The hematocrit is almost always ordered as part of a complete blood count, which measures the number of red blood cells, the number of white blood cells, the total amount of hemoglobin in the blood, and the fraction of the blood composed of red blood cells (hematocrit). The hematocrit indicates the proportion of cells and fluids in the blood.

Performed

Blood is drawn from a vein, usually on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to swell with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

For infants or young children, the area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

In the laboratory, some of the blood is centrifuged (spun in a machine). This forces the cells to the bottom of the container. The cellular portion is compared with the total amount of blood and expressed as a percent. The cellular portion is almost entirely red blood cells. The percent that is white blood cells is very small.

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Prepare for the HTC test

No special preparation is necessary for this test. For infants and children, the preparation you can provide for this test depends on your child's age (infant – birth to 1 yr, toddler – 1 to 3 yr, preschooler – 3 to 6 yr, schoolage – 6 to 12yr, adolescent 12 to 18 yr), previous experiences, and level of trust.

There are some risks after got this test,

  • excessive bleeding
  • fainting or feeling light-headed
  • hematoma (blood accumulating under the skin)
  • infection (a slight risk any time the skin is broken)
  • multiple punctures to locate veins

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

The results mean

Hematocrit (varies with altitude):

  • Male: 40.7-50.3%
  • Female: 36.1-44.3%

Low hematocrit may indicate:

  • anemia (various types)
  • blood loss (hemorrhage)
  • bone marrow failure (e.g., due to radiation, toxin, fibrosis, tumor)
  • destruction of red blood cells
  • leukemia
  • malnutrition or specific nutritional deficiency
  • multiple myeloma
  • rheumatoid arthritis

High hematocrit may indicate:

  • dehydration
    • burns
    • diarrhea
  • erythrocytosis (excessive red blood cell production)
  • polycythemia vera

This test may be performed under many other conditions and in the assessment of many disease states.

Platelet count

Bleeding disorders or other bone marrow diseases, such as leukemia, require the determination of the number of platelets present and/or their ability to function correctly.

A platelet count is often ordered as a standard part of a complete blood count, which may be done as part of an annual physical examination. It is almost always ordered when a patient has unexplained bruises or takes what appears to be an unusually long time to stop bleeding from a small cut or wound.

The result mean

In an adult, a normal count is about 150,000 to 450,000 platelets per microliter (x 10–6/Liter) of blood.

If platelet levels fall below 20,000 per microliter, spontaneous bleeding may occur and is considered a life-threatening risk. Patients who have a bone marrow disease, such as leukemia or other cancer in the bone marrow, often experience excessive bleeding due to a significantly decreased number of platelets (thrombocytopenia). Low number of platelets may occur in some patients with long-term bleeding problems (e.g., chronic bleeding stomach ulcers), thus reducing the supply of platelets. Individuals with an autoimmune disorder (such as lupus or Idiopathic Thrombocytopenia Purpura [ITP], where the body’s immune system creates antibodies that attack its own organs) can cause the destruction of platelets. Certain drugs, such as heparin, quinidine, sulfa drugs, oral anti-diabetic drugs, and even alcohol, may cause decreased platelet counts. Patients undergoing chemotherapy may also have a decreased platelet count. Up to 5% of pregnant women may experience thrombocytopenia at term.

More commonly (up to 1% of the population), easy bruising or bleeding may be due to an inherited disease called von Willebrand’s disease. While the platelets may be normal in number, their ability to stick together is impaired due to a decrease in von Willebrand’s factor, a protein needed to initiate the clotting process. Many cases go undiagnosed due to the mild nature of the disease; however, the more severe form can be devastating.

Increased platelet counts (thrombocytosis) may be seen in individuals who show no significant medical problems, while others may have a more significant blood problem called myeloproliferative disorder (abnormal growth of blood cell elements). Some may have a tendency to bleed due to the lack of stickiness of the platelets, yet in others, the platelets retain their stickiness but, because they are increased in number, tend to stick to each other, forming a clump that can get stuck within a blood vessel and cause damage, including death (thromboembolism).

Living in high altitudes may cause increased platelet levels, as can strenuous exercise.

Decreased levels may be seen in women before menstruation.

Drugs that may cause increased platelet levels include estrogen and oral contraceptives.

Other inherited disorders caused by defective platelets or decreased/absent proteins that activate the platelets include Glanzmann’s Throbasthenia, Bernard-Soulier disease, Chediak-Higashi syndrome, Wiskott-Aldrich syndrome, May-Hegglin syndrome, and Down syndrome. The occurrence of these abnormalities, however, is relatively rare.

Electrolytes

Electrolytes or serum chemistries are minerals in your blood and other body fluids that carry an electric charge. It is important for the balance of electrolytes in your body to be maintained, because they affect the amount of water in your body, blood pH, muscle action, and other important processes. You lose electrolytes when you sweat, and these must be replenished by drinking lots of fluids.

Electrolytes exist in the blood as acids, bases, and salts (such as sodium, calcium, potassium, chlorine, magnesium, and bicarbonate) and can be measured by laboratory studies of the blood serum.

Tourniquet test

This test determines capillary fragility. It is also known as a Rumpel-Leede Capillary-Fragility Test or simply a capillary fragility test. It is a clinical diagnostic method to determine bleeding tendencies in a person who might have a disease such as dengue fever. It assesses fragility of capillary walls, evaluates bleeding tendencies, and identifies thrombocytopenia (a reduced platelet count).

In dengue, the test is defined by the WHO. A blood pressure cuff is inflated to a point between the systolic and diastolic blood pressures for five minutes. The test is positive if there are more than 20 petechiae per square inch (a petechia is a small red or purple spot on the body, caused by a minor hemorrhage).

Titer

A titer is a measurement of the amount or concentration of a substance in a solution. It usually refers to the amount of medicine or antibodies found in a patient's blood. Blood titer measurements can be very helpful in determining medical treatment. Antibody titers can tell the doctor if the patient has immunity to diseases such as measles, small pox, and hepatitis. Medication titers can tell if a person is receiving too much medication.

Dengue Hemorrhagic Fever (DHF) -- Prevention

Immunization

Vaccine development for dengue and DHF is difficult because any of four different viruses may cause disease, and because protection against only one or two dengue viruses could actually increase the risk of more serious disease. Nonetheless, progress is being made in the development of vaccines that may protect against all four dengue viruses. Such products may become available for public health use within several years.

Another Prevention and control

There is no commercially available vaccine for the dengue flavivirus. However, one of the many ongoing vaccine development programs is the Pediatric Dengue Vaccine Initiative (PDVI) which was set up in 2003 with the aim of accelerating the development and introduction of dengue vaccine(s) that are affordable and accessible to poor children in endemic countries.

At present, the only method of controlling or preventing dengue and DHF is to combat the vector mosquitoes.

In Asia and the Americas, Aedes aegypti breeds primarily in man-made containers like earthenware jars, metal drums and concrete cisterns used for domestic water storage, as well as discarded plastic food containers, used automobile tyres and other items that collect rainwater. In Africa it also breeds extensively in natural habitats such as tree holes and leaf axils.

In recent years, Aedes albopictus, a secondary dengue vector in Asia, has become established in: the United States, several Latin American and Caribbean countries, in parts of Europe and in one African country. The rapid geographic spread of this species has been largely attributed to the international trade in used tyres.

Vector control is implemented using environmental management and chemical methods. Proper solid waste disposal and improved water storage practices, including covering containers to prevent access by egg laying female mosquitoes are among methods that are encouraged through community-based programmes.

The application of appropriate insecticides to larval habitats, particularly those which are considered useful by the householders, e.g. water storage vessels, prevent mosquito breeding for several weeks but must be re-applied periodically. Small, mosquito-eating fish and copepods (tiny crustaceans) have also been used with some success. During outbreaks, emergency control measures may also include the application of insecticides as space sprays to kill adult mosquitoes using portable or truck-mounted machines or even aircraft. However, the killing effect is only transient, variable in its effectiveness because the aerosol droplets may not penetrate indoors to microhabitats where adult mosquitoes are sequestered, and the procedure is costly and operationally very demanding. Regular monitoring of the vectors' susceptibility to the most widely used insecticides is necessary to ensure the appropriate choice of chemicals. Active monitoring and surveillance of the natural mosquito population should accompany control efforts in order to determine the impact of the programme.

Application of larvicides such as Abate® to standing water is more effective in the long term control of mosquitoes. Initiatives to eradicate pools of standing water (such as in flowerpots) have proven useful in controlling mosquito-borne diseases. Promising new techniques have been recently reported from Oxford University on rendering the Aedes mosquito pest sterile.

Personal prevention consists of the use of mosquito nets, repellents, cover exposed skin, use DEET-impregnated bednets, and avoiding endemic areas. This is also important for malaria prevention.

Potential Antiviral Approaches

In cell culture experiments Morpholino antisense oligos have shown specific activity against Dengue virus.

In 2002 the Swiss pharma company Novartis and the Singapore Economic Development board created the Novartis Institute for Tropical Diseases (NITD). NITD is a public-private partnership that researches neglected tropical disease. NITD's dengue unit is researching anti-viral drug discovery to treat or prevent dengue fever.

In 2006, a group of Argentine scientists directed by Andrea Gamarnik discovered the molecular replication mechanism of the virus, which could be attacked by disruption the polymerase's work.

What are signs and symptoms??
How the tests are going??

Dengue Hemorrhagic Fever (DHF) -- Signs, Symptoms and Treatment

Signs and Symptoms

Dengue fever is a severe, flu-like illness that affects infants, young children and adults, but seldom causes death.

The clinical features of dengue fever vary according to the age of the patient. Infants and young children may have a non-specific febrile illness with rash. Older children and adults may have either a mild febrile syndrome or the classical incapacitating disease with abrupt onset and high fever, severe headache, pain behind the eyes, muscle and joint pains, and rash.

Early symptoms include the following:

  • Fever
  • Headache
  • Muscle aches
  • Joint aches
  • Malaise
  • Decreased appetite
  • Vomiting

Acute phase symptoms include the following:

  • Shock-like state
    • Sweaty (diaphoretic)
    • Cold, clammy extremities
  • Restlessness followed by:
    • Worsening of earlier symptoms
    • Petechiae
    • Ecchymosis
    • Generalized rash

This infectious disease is manifested by a sudden onset of fever, with severe headache, muscle and joint pains (myalgias and arthralgias — severe pain gives it the name break-bone fever or bonecrusher disease) and rashes; the dengue rash is characteristically bright red petechia and usually appears first on the lower limbs and the chest - in some patients, it spreads to cover most of the body. There may also be gastritis with some combination of associated abdominal pain, nausea, vomiting or diarrhea.

Dengue haemorrhagic fever is a potentially deadly complication that is characterized by high fever, haemorrhagic phenomena--often with enlargement of the liver--and in severe cases, circulatory failure. The illness commonly begins with a sudden rise in temperature accompanied by facial flush and other non-specific constitutional symptoms of dengue fever. The fever usually continues for two to seven days and can be as high as 40-41°C, possibly with febrile convulsions and haemorrhagic phenomena.

Some cases develop much milder symptoms, which can, when no rash is present, be misdiagnosed as the flu or other viral infection. Thus, travelers from tropical areas may inadvertently pass on dengue in their home countries, having not being properly diagnosed at the height of their illness. Patients with dengue can only pass on the infection through mosquitoes or blood products while they are still febrile.

The classic dengue fever lasts about six to seven days, with a smaller peak of fever at the trailing end of the fever (the so-called "biphasic pattern"). Clinically, the platelet count will drop until the patient's temperature is normal.

In moderate DHF cases, all signs and symptoms abate after the fever subsides. Cases of DHF also shows higher fever, haemorrhagic phenomena, thrombocytopenia and haemoconcentration. A small proportion of cases leads to dengue shock syndrome (DSS) which has a high mortality rate. In severe cases, the patient's condition may suddenly deteriorate after a few days of fever; the temperature drops, followed by signs of circulatory failure, and the patient may rapidly go into a critical state of shock and die within 12-24 hours, or quickly recover following appropriate volume replacement therapy.

Treatment

Because Dengue hemorrhagic fever is caused by a virus for which there is no known cure or vaccine, the only treatment is to treat the symptoms.

  • The mainstay of treatment is supportive therapy. The patient is encouraged to keep up oral intake, especially of oral fluids.
  • Rehydration with intravenous (IV) fluids is often necessary to treat dehydration.
  • IV fluids and electrolytes are also used to correct electrolyte imbalances.
  • A transfusion of fresh blood or platelets can correct bleeding problems. But the transfusion is recommendable on platelet count falling below 20,000 without hemorrhage / bleeding or approx 50,000 with hemorrhage/bleeding. Internal bleeding indicated by dark color of stools, other bleedings indicated at surface as red rashes all over or most of the body parts. A platelet transfusion is rarely indicated if the platelet level drops significantly or if there is significant bleeding.
  • Oxygen therapy may be needed to treat abnormally low blood oxygen.

Dengue Hemorrhagic Fever (DHF)

Dengue fever and dengue hemorrhagic fever (DHF) are acute febrile diseases, found in the tropics, with a geographical spread similar to malaria. Caused by one of four closely related virus serotypes of the genus Flavivirus, family Flaviviridae, each serotype is sufficiently different that there is no cross-protection and epidemics caused by multiple serotypes (hyperendemicity) can occur. Dengue is found in tropical and sub-tropical regions around the world, predominantly in urban and semi-urban areas.

Alternative names are Hemorrhagic dengue, Dengue shock syndrome, Philippine hemorrhagic fever, Thai hemorrhagic fever, Singapore hemorrhagic fever.

Dengue is transmitted to humans by the mosquito Aedes aegypti (rarely Aedes albopictus).

Dengue haemorrhagic fever (DHF), a potentially lethal complication, was first recognized in the 1950s during the dengue epidemics in the Philippines and Thailand, but today DHF affects most Asian countries and has become a leading cause of hospitalisation and death among children in several of them.

There are four distinct, but closely related, viruses that cause dengue. Recovery from infection by one provides lifelong immunity against that serotype but confers only partial and transient protection against subsequent infection by the other three. There is good evidence that sequential infection increases the risk of more serious disease resulting in DHF.

Diagnosis

The diagnosis of dengue is usually made clinically. The classic picture is high fever with no localising source of infection, a petechial rash with thrombocytopenia and relative leukopenia.

There exists a WHO definition of dengue haemorrhagic fever that has been in use since 1975; all four criteria must be fulfilled:

  1. Fever
  2. Haemorrhagic tendency (positive tourniquet test, spontaneous bruising, bleeding from mucosa, gingiva, injection sites, etc.; vomiting blood, or bloody diarrhea)
  3. Thrombocytopaenia (<100,000>
  4. Evidence of plasma leakage (hematocrit more than 20% higher than expected, or drop in haematocrit of 20% or more from baseline following IV fluid, pleural effusion, ascites, hypoproteinaemia)

Dengue shock syndrome is defined as dengue haemorrhagic fever plus

  • Weak rapid pulse,
  • Narrow pulse pressure (less than 20 mm Hg)

or,

  • Hypotension for age;
  • Cold, clammy skin and restlessness.

Serology and PCR (polymerase chain reaction) studies are available to confirm the diagnosis of dengue if clinically indicated.

Epidemiology

The term "dengue" is a Spanish attempt at the (Swahili language)phrase "ki denga pepo", meaning "cramp-like seizure caused by an evil spirit". It emerged during a Caribbean outbreak in 1827-1828.

Outbreaks resembling dengue fever have been reported throughout history. The first case report dates back from 1789 and is attributed to Benjamin Rush, who coined the term "breakbone fever" (because of the symptoms of myalgia and arthralgia). The viral etiology and the transmission by mosquitoes were only deciphered in the 20th century. The socioeconomic impact of World War II resulted in increased spread globally.

The global prevalence of dengue has grown dramatically in recent decades. The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-east Asia and the Western Pacific. South-east Asia and the Western Pacific are most seriously affected. Before 1970 only nine countries had experienced DHF epidemics, a number that had increased more than four-fold by 1995.

The first epidemics occurred almost simultaneously, in Asia, Africa, and North America in the 1780s. The disease was identified and named in 1779. A global pandemic began in Southeast Asia in the 1950s and by 1975 DHF had become a leading cause of death among children in many countries in that region. Epidemic dengue has become more common since the 1980s - by the late 1990s, dengue was the most important mosquito-borne disease affecting humans after malaria, there being around 40 million cases of dengue fever and several hundred thousand cases of dengue hemorrhagic fever each year. In February 2002 there was a serious outbreak in Rio de Janeiro, affecting around one million people but only killing sixteen.

Significant outbreaks of dengue fever tend to occur every five or six years. There tend to remain large numbers of susceptible people in the population despite previous outbreaks because there are four different strains of the dengue virus and because of new susceptible individuals entering the target population, either through childbirth or immigration.

There is significant evidence, originally suggested by S.B. Halstead in the 1970s, that dengue hemorrhagic fever is more likely to occur in patients who have secondary infections by serotypes different from the primary infection. This is due to a process known as antibody-dependent enhancement (ADE), which allows for increased uptake and virion replication during a secondary infection with a different strain. Through an immunological phenomena, known as original antigenic sin, the immune system is not able to adequately respond to the stronger infection, and the secondary infection becomes far more serious.

Some 2500 million people -- two fifths of the world's population -- are now at risk from dengue. WHO currently estimates there may be 50 million cases of dengue infection worldwide every year.

In 2001 alone, there were more than 609 000 reported cases of dengue in the Americas, of which 15 000 cases were DHF. This is greater than double the number of dengue cases which were recorded in the same region in 1995.

Not only is the number of cases increasing as the disease is spreading to new areas, but explosive outbreaks are occurring. In 2001, Brazil reported over 390 000 cases including more than 670 cases of DHF.

Some other statistics:

  • During epidemics of dengue, attack rates among susceptibles are often 40 -- 50%, but may reach 80 -- 90%.
  • An estimated 500 000 cases of DHF require hospitalisation each year, of whom a very large proportion are children. At least 2.5% of cases die, although case fatality could be twice as high.
  • Without proper treatment, DHF case fatality rates can exceed 20%. With modern intensive supportive therapy, such rates can be reduced to less than 1%.

The spread of dengue is attributed to expanding geographic distribution of the four dengue viruses and of their mosquito vectors, the most important of which is the predominantly urban species Aedes aegypti. A rapid rise in urban populations is bringing ever greater numbers of people into contact with this vector, especially in areas that are favourable for mosquito breeding, e.g. where household water storage is common and where solid waste disposal services are inadequate.

In Singapore, there are about 4,000-5,000 reported cases of dengue fever or dengue haemorrhagic fever every year. In the year 2003, there were 6 deaths from dengue shock syndrome. It is believed that the reported cases of dengue are an underrepresentation of all the cases of dengue as it would ignore subclinical cases and cases where the patient did not present for medical treatment. With proper medical treatment, the mortality rate for dengue can therefore be brought down to less than 1 in 1000.

What are signs and symptoms??
How to Prevent??
How the tests are going??