Tag: Group A streptococcal infection

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Ailmemts & Remedies

Group B Streptococcus (GBS) Infection

Definition:
Infection with Group B Streptococcus (GBS), also known as ‘Streptococcus agalactiae’ and more colloquially as Strep B and group B Strep, can cause serious illness and sometimes death, especially in newborn infants, the elderly, and patients with compromised immune systems. Group B streptococci are also prominent veterinary pathogens, because they can cause bovine mastitis (inflammation of the udder) in dairy cows. The species name “agalactiae” meaning “no milk”, alludes to this.

Streptococcus is a genus of spherical, Gram-positive bacteria of the phylum Firmicutes. Streptococcus agalactiae is a gram-positive streptococcus characterized by the presence of Group B Lancefield antigen, and so takes the name Group B Streptococcus.

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This type of bacteria (not to be confused with group A strep which causes “strep throat”) is commonly found in the human body, and it usually does not cause any symptoms. However, in certain cases it can be a dangerous cause of various infections that affect pregnant women & their newborns .

Group B streptococcal infections affect one in 2,000 babies born every year in the UK and Ireland. About 340 babies a year will develop group B streptococcal infection within seven days of birth (early group B streptococcus disease).

Causes:
The bacteria is found living harmlessly in the vaginal and gastrointestinal tracts of up to 50 per cent of healthy women (and in many men too). It may be passed on to a baby either while the baby is still in the womb or during delivery. Although about 50 per cent of babies born to mothers carrying group B streptococcus pick up the micro-organism, only about one to two per cent of these newborns then go on to develop severe group B streptococcal disease.

Group B streptococcal sepsis is most likely to develop when the baby is premature or if there has been prolonged rupture of the membranes, with many hours passing before the baby is born, or if the baby has no antibodies to group B streptococci.

In the last 30 years it’s been show to be a cause of serious infection in non-pregnant adults too. It’s extremely rare in healthy people and is almost always associated with underlying problems such as diabetes or cancer, or less often, problems with:

•Heart and blood vessels
•Genitourinary system
•Liver disease
•Kidney disease

About five per cent of affected adults will eventually experience a second episode of group B streptococcal disease.

How is group B strep transmitted?
In newborns, GBS infection is acquired through direct contact with the bacteria while in the uterus or during delivery; thus the infection is transmitted from the colonized mother to her newborn. However, not every baby born to a colonized mother will develop GBS infection. Statistics show that about one of every 100-200 babies born to a GBS-colonized mother will develop GBS infection.

There are maternal risk factors, however, that increase the chance of transmitting the disease to the newborn:

•labor or membrane rupture before 37 weeks
•membrane rupture more than 18 hours before delivery
•urinary tract infection with GBS during pregnancy
•previous baby with GBS infection
•fever during labor
•positive culture for GBS colonization at 35-37 weeks
.
Group B strep infection is not a sexually transmitted disease (STD).

Symptoms :
If a pregnant woman is carrying (or ‘colonised with’) group B streptococcus, there is a chance she could pass it to her unborn baby. Most babies will not be harmed and will simply carry the bacteria themselves, but it can cause:

•Early birth
•Stillbirth
•Late miscarriage and complications
Group B streptococcal disease in newborns is divided into early and late disease. Early group B streptococcal neonatal sepsis appears within 24 hours of delivery (and up to seven days afterwards) and accounts for over 80 per cent of cases. Typically it causes signs of pneumonia (breathing problems) or, less often, meningitis. Most of these babies will make a full recovery.

Late group B streptococcal neonatal sepsis appears between one week and three months after birth, and is more likely to cause meningitis. One in ten infected babies will die of blood poisoning, pneumonia or meningitis, while one in five will be affected permanently by cerebral palsy, blindness, deafness or serious learning difficulties.

Once a baby has reached three months of age, group B streptococcal infection is extremely rare.

In vulnerable adults, group B streptococcus can cause a range of different infections at different sites in the body.

Diagnosis:
In pregnant women, routine screening for colonization with GBS is recommended. This test is generally performed between 35-37 weeks of gestation. The test involves using a swab to collect a sample from both the vaginal and rectal area, and results are usually available within 24-72 hours.

In newborns, GBS infection can be diagnosed with blood tests and/or spinal-fluid analysis. Similar testing may be used to diagnose the disease in adults.

Treatment:
For women who test positive for GBS during pregnancy and for those with certain risk factors for developing or transmitting GBS infection during pregnancy, intravenous antibiotics are generally recommended at the time of labor (before delivery). The administration of antibiotics has been shown to significantly decrease GBS infection in newborns. If a pregnant carrier of GBS receives intravenous antibiotics prior to delivery, her baby has a one in 4,000 chance of developing GBS infection. Without antibiotics, her baby has a one in 200 chance of developing GBS infection.

In adults who develop GBS infection, whether they are pregnant women or individuals with chronic medical conditions, intravenous(IV) antibiotics are also recommended.

At this point in time, the best treatment for GBS infection is prevention through routine screening during pregnancy. This testing has served to decrease the overall number of GBS infections in newborns, and there is currently research underway to develop a GBS vaccine.

Should all at-risk women be treated?
Some women prefer not to receive antibiotics if their risk is only slightly increased. Experts advise that the risk of infection in the baby must be balanced against the wishes and beliefs of the woman in labour and against her risk of an adverse reaction to the antibiotics. If a group B streptococcus carrying woman had a healthy baby in a previous pregnancy, she is unlikely to be at greater risk with following pregnancies.

Scientists are trying to develop a vaccine for group B streptococcus, but technical problems mean that it’s likely to be some years before one is available.

Prevention:
Through collaborative efforts clinicians, researchers, professional organizations, parent advocacy groups, and the public health community developed recommendations for intrapartum prophylaxis to prevent perinatal GBS disease. Many organizations have developed perinatal GBS disease prevention and education programs to reduce the incidence of the disease. Information about the recommendations and the prevention programs can be found in medical journals and on the internet. Simple anti-septic wipes do not prevent mother-to-child transmission

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://www.medicinenet.com/group_b_strep/article.htm
http://www.bbc.co.uk/health/physical_health/conditions/group_b_streptococcus_infection.shtml
http://en.wikipedia.org/wiki/Group_B_streptococcal_infection
http://www.trying-to-conceive.com/pregnancy/preventing-group-b-strep-%E2%80%93-is-it-possible/
http://www.medicaldaily.com/news/20110211/5422/third-trimester-group-b-streptococcus-test-doesnt-accurately-predict-presence-during-labor.htm

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Diagnonistic Test

Pulmonary Function Tests

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Alternative Names: PFTs; Spirometry; Spirogram; Lung function tests
Definition:Pulmonary function tests are a group of tests that measure how well the lungs take in and release air and how well they move oxygen into the blood. These tests can tell your doctor what quantity of air you breathe with each breath, how efficiently you move air in and out of your lungs.
.CLICK & SEE
Pulmonary Function Testing has been a major step forward in assessing the functional status of the lungs as it relates to :

1.How much air volume can be moved in and out of the lungs
2.How fast the air in the lungs can be moved in and out
3.How stiff are the lungs and chest wall – a question about compliance
4.The diffusion characteristics of the membrane through which the gas moves (determined by special tests)
5.How the lungs respond to chest physical therapy procedures

Pulmonary Function Tests are used for the following reasons :

1.Screening for the presence of obstructive and restrictive diseases

2.Evaluating the patient prior to surgery – this is especially true of patients who :
a. are older than 60-65 years of age
b. are known to have pulmonary disease
c. are obese (as in pathologically obese)
d. have a history of smoking, cough or wheezing
e. will be under anesthesia for a lengthy period of time
f. are undergoing an abdominal or a thoracic operation

Note : A vital capacity is an important preoperative assessment tool. Significant reductions in vital capacity (less than 20 cc/Kg of ideal body weight) indicates that the patient is at a higher risk for postoperative respiratory complications. This is because vital capacity reflects the patient’s ability to take a deep breath, to cough, and to clear the airways of excess secretions.

3.Evaluating the patient’s condition for weaning from a ventilator. If the patient on a ventilator can demonstrate a vital capacity (VC) of 10 – 15 ml/Kg of body weight, it is generally thought that there is enough ventilatory reserve to permit (try) weaning and extubation.

4.Documenting the progression of pulmonary disease – restrictive or obstructive

5.Documenting the effectiveness of therapeutic intervention

How do you prepare for the test?
Do not eat a heavy meal before the test. Do not smoke for 4 – 6 hours before the test. You’ll get specific instructions if you need to stop using bronchodilators or inhaler medications. You may have to breathe in medication before the test.

No other preparation is necessary.

How the Test Will Feel ?
Since the test involves some forced breathing and rapid breathing, you may have some temporary shortness of breath or light-headedness. You breathe through a tight-fitting mouthpiece, and you’ll have nose clips.

What happens when the test is performed?
This testing is done in a special laboratory. During the test, you are instructed to breathe in and out through a tube that is connected to various machines.

A test called spirometry measures how forcefully you are able to inhale and exhale when you are trying to take as large a breath as possible. The lab technicians encourage you to give this test your best effort, because you can make the test result abnormal just by not trying hard.

A separate test to measure your lung volume (size) is done in one of two ways. One way is to have you inhale a small carefully measured amount of a specific gas (such as helium) that is not absorbed into your bloodstream. This gas mixes with the air in your lungs before you breathe it out again. The air and helium that you breathe out is tested to see how much the helium was diluted by the air in your lungs, and a calculation can reveal how much air your lungs were holding in the first place.

The other way to measure lung volume is with a test called plethysmography. In this test, you sit inside an airtight cubicle that looks like a phone booth, and you breathe in and out through a pipe in the wall. The air pressure inside the box changes with your breathing because your chest expands and contracts while you breathe. This pressure change can be measured and used to calculate the amount of air you are breathing.

Your lungs’ efficiency at delivering oxygen and other gases to your bloodstream is known as your diffusion capacity. To measure this, you breathe in a small quantity of carbon monoxide (too small a quantity to do you any harm), and the amount you breathe out is measured. Your ability to absorb carbon monoxide into the blood is representative of your ability to absorb other gases, such as oxygen.

Some patients have variations of these tests-for example, with inhaler medicines given partway through a test to see if the results improve, or with a test being done during exercise. Some patients also have their oxygen level measured in the pulmonary function lab (see “Oxygen saturation test,” page 29).

Why the Test is Performed  ?

Pulmonary function tests are done to:
*Diagnose certain types of lung disease (especially asthma, bronchitis, and emphysema)
*Find the cause of shortness of breath
*Measure whether exposure to contaminants at work affects lung function
It also can be done to:

*Assess the effect of medication
*Measure progress in disease treatment
*Spirometry measures airflow. By measuring how much air you exhale, and how quickly, spirometry can evaluate a broad range of lung diseases.

Lung volume measures the amount of air in the lungs without forcibly blowing out. Some lung diseases (such as emphysema and chronic bronchitis) can make the lungs contain too much air. Other lung diseases (such as fibrosis of the lungs and asbestosis) make the lungs scarred and smaller so that they contain too little air.

Testing the diffusion capacity (also called the DLCO) allows the doctor to estimate how well the lungs move oxygen from the air into the bloodstream.

Risk Factors:
The risk is minimal for most people. There is a small risk of collapsed lung in people with a certain type of lung disease. The test should not be given to a person who has experienced a recent heart attack, or who has certain other types of heart disease.

Must you do anything special after the test is over?
Nothing.

Normal Results:
Normal values are based upon your age, height, ethnicity, and sex. Normal results are expressed as a percentage. A value is usually considered abnormal if it is less than 80% of your predicted value.

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean:
Abnormal results usually mean that you may have some chest or lung disease.

Considerations:
Your cooperation while performing the test is crucial in order to get accurate results. A poor seal around the mouthpiece of the spirometer can give poor results that can’t be interpreted. Do not smoke before the test.

How long is it before the result of the test is known?
Your doctor will receive a copy of your test results within a few days and can review them with you then.

Resources:
https://www.health.harvard.edu/diagnostic-tests/pulmonary-function-testing.htm
http://www2.nau.edu/~daa/lecture/pft.htm
http://www.nlm.nih.gov/medlineplus/ency/article/003853.htm

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Diagnonistic Test

Rapid Strep Test (RADT)

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For a rapid strep test, the throat and tonsils are swabbed to collect bacteria from the infected area for testing. The bacteria are analyzed to see whether strep (streptococcal) bacteria are causing the sore throat.

.This scanning electron micrograph shows disease-causing Streptococcus bacteria, commonly found in the human mouth, throat, respiratory tract, bloodstream, and wounds. Often airborne in hospitals, schools, and other public places, Streptococcus bacteria are responsible for infections such as strep throat, scarlet fever, and some types of pneumonia.

A throat infection with streptococcus bacteria (called strep throat) needs to be treated with an antibiotic. A test is commonly used to find out whether streptococcus bacteria are present on your throat surface. The traditional test for a strep throat has been a throat culture, which takes two to three days to produce results. Several different types of rapid strep tests, however, can produce results within minutes to hours. A rapid strep test can only detect the presence of Group A strep, the one most likely to cause serious throat infections; it does not detect other kinds of strep or other bacteria.

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A good sample of throat secretions is needed to make sure the test is accurate. A person must remain very still during the procedure so that the doctor is able to collect enough secretions for an accurate test.

The Rapid Strep Test works by detecting the presence of a carbohydrate antigen unique to Group A Streptococcus. This may account for some of the problems with the Rapid Strep Test sensitivity. Gargling, eating or other infusion of liquids into the mouth prior to the test may affect the results. If the test is performed before sufficient organisms are present in the throat, or late in the infection when most of the strep germs have been cleared by the immune system, or if it is performed after someone has been partially treated with antibiotics that kill the organism, then the Rapid Strep Test is less likely to detect the organism.

If the Rapid Strep Test detects strep, the infection should be treated with appropriate antibiotics to prevent long-term damage and sequelae. Should the Rapid Strep Test fail to detect strep throat, the clinician might still treat the throat infection based on his or her own judgment.

How do you prepare for the test?
No preparation is necessary.

When it is required to do?

A rapid strep test may be done in the following cases:

*A person has symptoms of strep throat infection.

*A person has been exposed to strep during an epidemic of rheumatic fever.

The person has a personal or family history of rheumatic fever or other serious infections (such as toxic shock syndrome) and has been exposed to strep. In these cases, if there are no symptoms, a culture may be done first because it is more accurate than a rapid strep test.

In general, it is not necessary to test people who have been exposed to strep throat but do not have any symptoms.

What happens when the test is performed?
A cotton swab is rubbed against the back of your throat to gather a sample of mucus. This takes only a second or two and makes some people feel a brief gagging or choking sensation. The mucus sample is then tested for a protein that comes from the strep bacteria.


Risk factor.:-
There are no risks.

Anything to be done after the test?
Nothing

How long is it before the result of the test is known?
Results may be available in minutes to a few hours. Often the doctor will ask you to wait in the office until the result is back.

Results:-
Findings of a rapid strep test may include the following:

Normal
A normal or negative test means that strep bacteria may not be present.

Sometimes, negative results are wrong. This means that you may have a negative rapid strep test result and still have strep throat.
A throat culture may be done if the rapid strep test result is negative.

Abnormal
An abnormal or positive strep test means that strep bacteria are present.

Antibiotic treatment can be started.
A positive test result does not distinguish those people with an active strep infection from those who are carriers of strep bacteria but actually have a viral infection (rather than a bacterial one).
What To Think About:
The rapid strep test costs less than a throat culture and may diagnose strep throat quickly

Resources:
https://www.health.harvard.edu/diagnostic-tests/rapid-strep-test.htm
http://www.webmd.com/a-to-z-guides/rapid-strep-test-for-strep-throat
http://en.wikipedia.org/wiki/RADT

http://encarta.msn.com/media_461520073_761574409_-1_1/streptococcus_bacteria.html

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