R A B I E S

Key facts

• Rabies occurs in more than 150 countries and territories.
• Worldwide, more than 55 000 people die of rabies every year.
• 40% of people who are bitten by suspect rabid animals are children under 15 years of age.
• Dogs are the source of 99% of human rabies deaths.
• Wound cleansing and immunization within a few hours after contact with a suspect rabid animal can prevent the onset of rabies and death.
• Every year, more than 15 million people worldwide receive a post-exposure preventive regimen to avert the disease – this is estimated to prevent 327 000 rabies deaths annually.

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Rabies is a zoonotic disease (a disease that is transmitted to humans from animals) that is caused by a virus. The disease infects domestic and wild animals, and is spread to people through close contact with infected saliva via bites or scratches.
Rabies is present on all continents with the exception of Antartica, but more than 95% of human deaths occur in Asia and Africa. Once symptoms of the disease develop, rabies is nearly always fatal.

Symptoms

The incubation period for rabies is typically 1–3 months, but may vary from <1 week to >1 year. The initial symptoms of rabies are fever and often pain or an unusual or unexplained tingling, pricking or burning sensation (paraesthesia) at the wound site.
As the virus spreads through the central nervous system, progressive, fatal inflammation of the brain and spinal cord develops.
Two forms of the disease can follow. People with furious rabies exhibit signs of hyperactivity, excited behaviour, hydrophobia and sometimes aerophobia. After a few days, death occurs by cardio-respiratory arrest.
Paralytic rabies accounts for about 30% of the total number of human cases. This form of rabies runs a less dramatic and usually longer course than the furious form. The muscles gradually become paralyzed, starting at the site of the bite or scratch. A coma slowly develops, and eventually death occurs. The paralytic form of rabies is often misdiagnosed, contributing to the underreporting of the disease.

Patient with rabies, 1959

Diagnosis

No tests are available to diagnose rabies infection in humans before the onset of clinical disease, and unless the rabies-specific signs of hydrophobia or aerophobia are present, the clinical diagnosis may be difficult. Post mortem, the standard diagnostic technique is to detect rabies virus antigen in brain tissue by fluorescent antibody test.

Transmission

People are infected through the skin following a bite or scratch by an infected animal. Dogs are the main host and transmitter of rabies. They are the source of infection in all of the estimated 55 000 human rabies deaths annually in Asia and Africa.
Bats are the source of most human rabies deaths in the United States of America and Canada. Bat rabies has also recently emerged as a public health threat in Australia, Latin America and western Europe. Human deaths following exposure to foxes, raccoons, skunks, jackals, mongooses and other wild carnivore host species are very rare.
Transmission can also occur when infectious material – usually saliva – comes into direct contact with human mucosa or fresh skin wounds. Human-to-human transmission by bite is theoretically possible but has never been confirmed.
Rarely, rabies may be contracted by inhalation of virus-containing aerosol or via transplantation of an infected organ. Ingestion of raw meat or other tissues from animals infected with rabies is not a source of human infection.

Treatment after exposure

Effective treatment soon (within a few days, but as soon as possible) after exposure to rabies can prevent the onset of symptoms and death.
Post-exposure prevention consists of local treatment of the wound, administration of rabies immunoglobulin (if indicated), and immediate vaccination.

Local treatment of the wound

Removing the rabies virus at the site of the infection by chemical or physical means is an effective means of protection. Therefore, prompt local treatment of all bite wounds and scratches that may be contaminated with rabies virus is important. Recommended first-aid procedures include immediate and thorough flushing and washing of the wound for a minimum of 15 minutes with soap and water, detergent, povidone iodine or other substances that kill the rabies virus.

Recommended treatment

The recommended post-exposure prophylaxis depends on the type of contact with the suspected rabid animal (see table).

Table: Recommended post-exposure prophylaxis for rabies infection
Category of exposure to suspect rabid animal	Post-exposure measures
Category I – touching or feeding animals, licks on intact skin (i.e. no exposure)	None
Category II – nibbling of uncovered skin, minor scratches or abrasions without bleeding	Immediate vaccination and local treatment of the wound
Category III – single or multiple transdermal bites or scratches, licks on broken skin; contamination of mucous membrane with saliva from licks, exposures to bats.	Immediate vaccination and administration of rabies immunoglobulin; local treatment of the wound

Other factors that should be taken into consideration when deciding whether to initiate post-exposure prevention include:

• the likelihood of the implicated animal being rabid
• the clinical features of the animal and its availability for observation and laboratory testing.

In developing countries, the vaccination status of the suspected animal alone should not be considered when deciding whether to initiate prophylaxis or not.

Who is most at risk?

Dog rabies potentially threatens over 3.3 billion people in Asia and Africa. People most at risk live in rural areas where human vaccines and immunoglobulin are not readily available or accessible.
Poor people are at a higher risk, as the average cost of rabies post-exposure prophylaxis after contact with a suspected rabid animal is US$ 40 in Africa and US$ 49 in Asia, where the average daily income is about US$ 1–2 per person. In India, 20 000 rabies deaths (that is, about 2/100 000 population at risk) are estimated to occur annually; in Africa, the corresponding figure is 24 000 (about 4/100 000 population at risk).
Although all age groups are susceptible, rabies is most common in children aged under 15; on average 40 % of post-exposure prophylaxis regimens are given to children aged 5–14 years, and the majority are male.
Anyone in continual, frequent or increased danger of exposure to rabies virus – either by nature of their residence or occupation – is also at risk. Travellers with extensive outdoor exposure in rural high-risk areas where immediate access to appropriate medical care may be limited should be considered at risk regardless of duration of their stay. Children living in or visiting rabies-affected areas are at particular risk.

Prevention

Eliminating rabies in dogs

Rabies is a vaccine-preventable disease. The most cost-effective strategy for preventing rabies in people is by eliminating rabies in dogs through vaccination. Vaccination of animals (mostly dogs) has reduced the number of human (and animal) rabies cases in several countries, particularly in Latin America. However, recent increases in human rabies deaths in parts of Africa, Asia and Latin America suggest that rabies is re-emerging as a serious public health issue.
Preventing human rabies through control of domestic dog rabies is a realistic goal for large parts of Africa and Asia, and is justified financially by the future savings of discontinuing post-exposure prophylaxis for people.

Preventive immunization in people

Safe, effective vaccines also exist for human use. Pre-exposure immunization in people is recommended for travellers to high-risk areas in rabies-affected countries, and for people in certain high-risk occupations such as laboratory workers dealing with live rabies virus and other lyssaviruses, and veterinarians and animal handlers in rabies-affected areas. As children are at particular risk, their immunization could be considered if living in or visiting high risk areas.

source: http://www.who.int/mediacentre/factsheets/fs099/en/

Cell Phones Might Cause Brain Cance

Limited Evidence' Suggests Cell Phones 'Possibly Carcinogenic'

By Daniel J. DeNoon
WebMD Health News

Reviewed by Laura J. Martin, MD

May 31, 2011 -- The expert panel that evaluates cancer risks today said that cell phones might possibly cause brain cancer.

The announcement comes from the International Agency for Research on Cancer (IARC). Like the World Health Organization, the American Cancer Society relies on IARC for evaluation of cancer risks.

"After reviewing all the evidence available, the IARC working group classified radiofrequency electromagnetic fields as possibly carcinogenic to humans," panel chairman Jonathan Samet, MD, chair of preventive medicine at the USC Keck School of Medicine, said at a news teleconference. "We reached this conclusion based on a review of human evidence showing increased risk of glioma, a malignant type of brain cancer, in association with wireless phone use."

In finding cell phones to be "possibly carcinogenic," the IARC means that heavy cell phone use might -- or might not -- cause a specific form of brain cancer called glioma. The finding means that research is urgently needed to find out whether cell phones actually cause cancer, and how they might do it.

The IARC estimates that some 5 billion people worldwide have mobile phones. Lifetime exposure to the magnetic fields created by the phones -- particularly when they are held tightly against the head -- rapidly is increasing.

Children are at particular risk, not only because their skulls are thinner but also because their lifetime exposure to cell phones likely will be greater than the exposure of current adults.

Putting Possible Cancer Risk in Perspective

It's important to put the possible risk into context. Kurt Straif, MD, PhD, MPH, head of the IARC Monographs Program, notes that the IARC currently lists some 240 agents as "possibly carcinogenic," including dry cleaning fluid and some commonly used pesticides.

While the IARC doesn't make recommendations to consumers, Straif noted that there are precautions people can take.

"Some of the highest exposures come from using mobile phones for voice calls. If you text, or use hands-free devices, you lower exposure by at least [10-fold]," Straif said at the news conference. "So this is left to consumers to consider whether this level of evidence is enough for them to take such precautions."

Otis W. Brawley, MD, chief medical officer for the American Cancer Society, notes that the IARC is a highly credible group. But Brawley echoes Straif's advice: People who are worried can reduce their risk.

"On the other hand, if someone is of the opinion that the absence of strong scientific evidence on the harms of cell phone use is reassuring, they may take different actions, and it would be hard to criticize that," Brawley says in a news release.

John Walls, vice president for public affairs at CTIA, the trade group representing the wireless communications industry, notes that the IARC findings do not mean cell phones cause cancer -- and that the limited evidence on which the findings are based are far from conclusive.

"Based on previous assessments of the scientific evidence, the Federal Communications Commission has concluded that '[t]here's no scientific evidence that proves that wireless phone usage can lead to cancer.' The Food and Drug Administration has also stated that '[t]he weight of scientific evidence has not linked cell phones with any health problems,'" Walls notes in a news release.

Samet and colleagues will publish a summary of their findings in the July 1 issue ofThe Lancet, which is still in press.

SOURCES: IARC, news teleconference, May 31, 2011American Cancer Society, news release.News release, CTIA-The Wireless Association.International Agency for Research on Cancer web site.News release, International Agency for Research on Cancer.Jonathan Samet, MD, chair of preventive medicine, USC Keck School of Medicine.Kurt Straif, MD, PhD, MPH, head, International Agency for Research on Cancer Monographs Program. ©2011 WebMD, LLC. All Rights Reserved.

The Common Cold

The common cold

The common cold is arguably the most common illness in humans. According to the U.S. Centers for Disease Control and Prevention (CDC), it is also one of the most common causes of work and school absenteeism, with up to 22 million school days lost each year in the U.S. As the most frequently occurring illness in the world, it is also a leading cause of doctor visits.

What causes the common cold, and how is it spread?

Colds are caused by viral infections. Over 200 different viruses can cause cold symptoms of varying severity. Viruses that cause colds are spread from person to person through tiny droplets of mucus that enter the air from the nasal passages of infected persons and are inhaled by others. Colds can also be spread by touching surfaces that have been contaminated by contact with infected persons and then touching your mouth, nose, or eyes.

While it is impossible to completely prevent the spread of colds, there are steps you can take to reduce your and your family's chances of becoming infected with a virus that causes colds.

1. Wash your hands often.

This is probably the single best measure to prevent transmission of colds. Especially after shopping, going to the gym, or spending time in public places, hand washing is critical. Frequent hand washing can destroy viruses that you have acquired from touching surfaces used by other people. You can also carry a small tube of hand sanitizer or sanitizing hand wipes when visiting public places. Teach your children the importance of hand washing too.

2. Avoid touching your face.

Most importantly, avoid touching the nose, mouth, and eye areas if you are around someone with a cold or have been touching surfaces in a public area.

3. Don't smoke

Cigarette smoke can irritate the airways and increase susceptibility to colds and other infections. Even exposure to passive smoke can make you (or your children) more vulnerable to colds.

4. Use disposable items if a family member is infected.

Disposable cups can be thrown away after each use and prevent accidental spread of the virus from sharing of cups or glasses. This is particularly important if you have young children who may try to drink from others' cups.

5. Keep household surfaces clean.

Door knobs, drawer pulls, keyboards, light switches, telephones, remote controls, countertops, and sinks can all harbor viruses for hours after their use by an infected person. Wipe these surfaces frequently with soap and water or a disinfectant solution.

6. Wash toys

If your child has a cold, wash his or her toys as well when you are cleaning household surfaces and commonly-used items.

7. Use paper towels

Use paper towels in the kitchen and bathroom for hand washing. Germs can live for several hours on cloth towels. Alternatively, have separate towels for each family member and provide a clean one for guests.

8. Throw tissues away after use

Used tissues are sources of virus that can contaminate any surface where they are left.

10. Control stress

Studies have shown that people experiencing emotional stress have weakened immune systems and are more likely to catch a cold than their calmer counterparts.

9. Maintain a healthy lifestyle

While there isn't direct evidence to show that eating well or exercising can prevent colds, maintenance of a healthy lifestyle, with adequate sleep, good nutrition, and physical exercise can help ensure that your immune system is in good condition and ready to fight infection if it occurs.

source:http://www.emedicinehealth.com/slideshow_common_cold/article_em.htm

OSTEOPOROSIS

Osteoporosis is a disease characterized by low bone mass and loss of bone tissue that may lead to weak and fragile bones. If you have osteoporosis, you have an increased risk for fractured bones (broken bones).

Does Osteoporosis Only Affect the Elderly?

Osteoporosis has often been thought to be a condition that frail elderly women develop. However, the damage from osteoporosis begins much earlier in life. Because peak bone density is reached at approximately 25 years of age, it is important to build strong bones by that age, so that the bones will remain strong later in life. Adequate calcium intake and exercise are essential for building strong bones.

What Are the Symptoms of Osteoporosis?

Normal bone is composed of protein, collagen, and calcium, all of which give bone its strength. Bones that are affected by osteoporosis can break (fracture) with relatively minor injury that normally would not cause a bone to fracture.

The osteoporosis condition can be present without any symptoms for decades. Therefore, patients may not be aware of their osteoporosis until they suffer a painful fracture. Symptoms depend on the location of the fracture. 

Osteoporosis Symptoms: Fractures of the Spine

Fractures of the spine (vertebra) can cause severe "band-like" pain that radiates around from the back to the side of the body. Over the years, repeated spine fractures can cause chronic lower back pain as well as loss of height or curving of the spine, which gives the individual a hunched-back appearance of the upper back, referred to as a "dowager hump.

Osteoporosis Symptoms: Stress Fracture

A fracture that occurs during the course of normal activity is called a minimal trauma fracture or stress fracture. For example, some patients with osteoporosis develop stress fractures of the feet while walking or stepping off a curb.

Osteoporosis Symptoms: Hip Fracture

Hip fractures typically occur as a result of a fall. With osteoporosis, hip fractures can occur as a result of trivial accidents. Hip fractures may also be difficult to heal after surgical repair because of poor bone quality

What Are the Consequences of Osteoporosis?

Osteoporosis bone fractures are responsible for considerable pain, decreased quality of life, lost workdays, and disability. Up to 30% of patients suffering a hip fracture will require long-term nursing-home care. Some 20% of women with a hip fracture will die in the subsequent year as an indirect result of the fracture. In addition, once a person has experienced a spine fracture due to osteoporosis, he or she is at very high risk of suffering another such fracture in the near future (next few years).

What Factors Determine Bone Strength?

Bone mass (bone density) is the amount of bone present in the skeletal structure. Generally, the higher the bone density, the stronger the bones. Bone density is greatly influenced by genetic factors and can be affected by environmental factors and medications. For example, men have a higher bone density than women. African Americans have a higher bone density than Caucasian or Asian Americans. Normally, bone density accumulates during childhood and reaches a peak by around 25 years of age. Bone density is then maintained for about 10 years. After age 35, both men and women will normally lose 0.3%-0.5% of their bone density per year as part of the aging process

Menopause, Estrogen, and Osteoporosis

Estrogen is important in maintaining bone density in women. When estrogen levels drop after menopause, bone loss accelerates. During the first five to 10 years after menopause, women can suffer up to 2%-4% loss of bone density per year! This can result in the loss of up to 25%-30% of their bone density during that time period. Accelerated bone loss after menopause is a major cause of osteoporosis in women.

What Are the Risk Factors for Developing Osteoporosis? (continued)

• malabsorption (nutrients in the bowels are not properly absorbed)
• low estrogen levels
• chemotherapy
• loss of the menstrual period (amenorrhea)
• chronic inflammation
• immobility, such as after a stroke or any condition that interferes with walking
• hyperthyroidism (excessive thyroid hormone)
• hyperparathyroidism (excessive parathyroid hormone production causes too much calcium to be removed from the bone)
• vitamin D deficiency (vitamin D helps the body absorb calcium)
• certain medications can cause osteoporosis such as long-term use of heparin (a blood thinner), antiseizure medications phenytoin (Dilantin) and phenobarbital, and long-term use of oral corticosteroids (such as prednisone)

How Is Osteoporosis Diagnosed?

A routine X-ray can suggest osteoporosis of the bone, which appears much thinner and lighter than normal bones. Unfortunately, by the time X-rays can detect osteoporosis, at least 30% of the bone has already been lost. In addition, X-rays are not accurate indicators of bone density. The appearance of the bone on the X-ray is often affected by variations in the degree of exposure of the X-ray film.

The National Osteoporosis Foundation, the American Medical Association, and other major medical organizations are recommending a dual energy X-ray absorptiometry scan (DEXA or DXA) for diagnosing osteoporosis. The test measures bone density in the hip and the spine, takes only five to 15 minutes to perform, uses very little radiation (less than one-tenth to one-hundredth the amount used on a standard chest X-ray), and is quite precise.

Who should have bone density testing?

The National Osteoporosis Foundation guidelines state that there are several groups of people who should consider DXA testing:

• all postmenopausal women below age 65 who have risk factors for osteoporosis;
• all women aged 65 and older;
• postmenopausal women with fractures, although this is not mandatory because treatment may well be started regardless of bone density;
• women with one of the many medical conditions associated with osteoporosis; and
• women whose decision to use medication might be aided by bone density testing.

How Are Bone Density Results Measured?

Upon completion of a DXA scan, the bone density of the patient is then compared to the average peak bone density of young adults of same sex and race. This score is called the "T score," and it expresses the bone density in terms of the number of standard deviations (SD) below peak young adult bone mass.

• Osteoporosis is defined as a bone density T score of -2.5 SD or below.
• Osteopenia (between normal and osteoporosis) is defined as a bone density T score between -1 and -2.5 SD. all women aged 65 and older;

How Is Osteoporosis Treated and Prevented?

The goal of osteoporosis treatment is the prevention of bone fractures by stopping bone loss and by increasing bone density and strength. Although early detection and timely treatment of osteoporosis can substantially decrease the risk of future fracture, none of the available treatments for osteoporosis are complete cures. In other words, it is difficult to completely rebuild bone that has been weakened by osteoporosis.

Prevention and Treatment: Exercise

Exercise has a wide variety of beneficial health effects. However, exercise does not bring about substantial increases in bone density. The benefit of exercise for osteoporosis has mostly to do with decreasing the risk of falls, probably because balance is improved and/or muscle strength is increased. Research has not yet precisely determined what type or duration of exercise is best for osteoporosis. Nevertheless, most doctors recommend weight-bearing exercise, such as walking, preferably daily.

A Word of Caution About Exercise

It is important to avoid exercises that can injure already weakened bones. In patients over 40 and those with heart disease, obesity, diabetes mellitus, and high blood pressure, exercise should be prescribed and monitored by their doctors. Finally, extreme levels of exercise (such as marathon running) may not be healthy for the bones. Marathon running in young women that leads to weight loss and loss of menstrual periods can actually cause osteoporosis.

Prevention and Treatment: Quit Smoking and Curtail Alcohol

Smoking one pack of cigarettes per day throughout adult life can itself lead to loss of 5%-10% of bone mass. Smoking cigarettes decreases estrogen levels and can lead to bone loss in women before menopause. Smoking cigarettes can also lead to earlier menopause.

Data on the effect of regular consumption of alcohol and caffeine on osteoporosis is not as clear as with exercise and cigarettes. In fact, research regarding alcohol and caffeine as risk factors for osteoporosis shows widely varying results and is controversial. Certainly, these effects are not as powerful as other factors. Nonetheless, moderation of both alcohol and caffeine is prudent.

Prevention and Treatment: Calcium Supplements

Building strong and healthy bones requires an adequate dietary intake of calcium and exercise beginning in childhood and adolescence for both sexes. Importantly, once osteoporosis is present, a high dietary calcium intake or taking calcium supplements alone is not sufficient in treating osteoporosis and should not be viewed as an alternative to or substituted for more potent prescription osteoporosis medications. In the first several years after menopause, rapid bone loss can occur even if calcium supplements are taken.

Unfortunately, surveys have shown that the average woman in the United States consumes less than 500 milligrams of calcium per day in her diet, less than the recommended amounts. Additional calcium can be obtained by drinking more milk and eating more yogurt or cottage cheese or by taking calcium supplement tablets as well from calcium-fortified foods, such as orange juice.

Prevention and Treatment: Vitamin D

An adequate calcium intake and adequate body stores of vitamin D are important foundations for maintaining bone density and strength. Unfortunately, vitamin D deficiency is quite common in the United States. Vitamin D is important in several respects:

• vitamin D helps the absorption of calcium from the intestines;
• a lack of vitamin D causes calcium-depleted bone (osteomalacia), which further weakens the bones and increases the risk of fractures; and
• vitamin D, along with adequate calcium (1,200 mg of elemental calcium), has been shown in some studies to increase bone density and decrease fractures in older postmenopausal but not in premenopausal or perimenopausal women.

The Food and Nutrition Board of the Institute of Medicine has recommended the following as an as adequate vitamin D intake:

• 200 IU daily for men and women 19 to 50 years old;
• 400 IU daily for men and women 51 to 70 years old; and
• IU daily for men and women 71 years and older.

Good sources of vitamin D include natural sunlight, fortified milk, cheese, butter/margarine, cereal, and fish.

Prevention and Treatment: Menopausal Hormone Therapy

Menopausal hormone therapy (previously referred to as hormone replacement therapy or HRT) has been shown to prevent bone loss, increase bone density, and prevent bone fractures. Estrogen is available orally (Premarin, Estrace, Estratest, and others) or as a skin patch (Estraderm, Vivelle, and others). Estrogen is also available in combination with progesterone as pills and patches. Progesterone is routinely given along with estrogen to prevent uterine cancer that might result from estrogen use alone. Women who have had a hysterectomy (surgical removal of the uterus) may take estrogen alone. Due to adverse effects of menopausal hormone therapy, such as increased risks of heart attack, stroke, blood clots in the veins, and breast cancer; menopausal hormone therapy is no longer recommended for long-term use but rather short-term use to relieve menopausal hot flashes. Every woman should have an individualized discussion regarding estrogen replacement with her doctor.

Prevention and Treatment: Medications

Currently, the most effective medications for osteoporosis that are approved by the FDA are anti-resorptive agents, which prevent bone breakdown. Antiresorptive medications inhibit bone removal (resorption), thus tipping the balance in favor of bone rebuilding and increasing bone density. Menopausal estrogen hormone therapy is one example of an antiresorptive agent. Others include alendronate (Fosamax), risedronate (Actonel), raloxifene (Evista), ibandronate (Boniva), calcitonin (Calcimar), and zoledronate (Reclast).

Selective estrogen receptor modulators (SERMs) are a class of drugs that work like estrogen in some tissues. The SERMs are developed to reap the benefits of estrogen while avoiding the potential side effects of estrogen. Examples include tamoxifen and Raloxifene (Evista).

Prevention of Hip Fractures

The FDA has approved hip-protector garments for the prevention of hip fractures in unstable elderly people with known osteoporosis. Brand names available include Hipsaver and Safehip. These can be helpful for selected patients who are in the nursing-home environment, although the real extent of protection against hip fractures that is gained with use of hip protectors is a matter of current controversy.

Osteoporosis At A Glance

• Osteoporosis is a condition of increased susceptibility to fracture due to fragile bone.
• Osteoporosis weakens bone and increases risk of bone fracture.
• Bone mass (bone density) decreases after age 35 years and decreases more rapidly in women after menopause.
• Key risk factors for osteoporosis include genetic factors, lack of exercise, lack of calcium and vitamin D, personal history of fracture as an adult, rheumatoid arthritis, cigarette smoking, excessive alcohol consumption, low body weight, and family history of osteoporosis.
• Patients with osteoporosis have no symptoms until bone fractures occur.
• Diagnosis can be suggested by X-rays and confirmed by using tests to measure bone density.
• Treatments for osteoporosis, in addition to prescription osteoporosis medications, include stopping use of alcohol and cigarettes, and assuring adequate exercise, calcium, and vitamin D.

Reference:http://www.emedicinehealth.com/slideshow_osteoporosis_pictures/article_em.htm