Monday, August 29, 2011

On Chickenpox Worldwide

Chickenpox was once considered a rite of passage for most children, but since the establishment of routine vaccination programs, complications from the virus have seriously decreased. While the condition very seldom leads to secondary infections or other issues, it is highly contagious and can be problematic in some individuals. It is important that parents ensure their children receive vaccinations for chickenpox and other common childhood illnesses, and remain mindful when interacting with infected individuals.



In the 16th century, the varicella zoster virus (VZV), the virus that causes chickenpox was identified, but it was not until the end of the 19th century that physicians were able to reliably distinguish chickenpox from smallpox. VZV is a member of the herpes virus group, and like other herpes viruses, it has the capacity to persist in the body after the first infection as a latent infection and can reappear as shingles. Shingles, which manifests as a painful rash on one side of the body, occurs in approximately one in 10 adults. It is the result of re-activation of the VZV virus which persists as a latent infection in sensory nerve ganglia and can occur in any individual who has recovered from chickenpox, but it is most common in individuals over 60.

Spread through direct contact with the rash or droplets dispersed into the air by coughing or sneezing, chickenpox manifests as a red, itchy rash which first appears on the face, trunk, or scalp. The rash usually appears 10 to 21 days after infection, and may be accompanied by a fever, abdominal pain, headache, and a general feeling of unease and discomfort. If scratching the rash is not discouraged through the use of oatmeal or baking soda baths, the application of calamine lotion, or antihistamines, individuals may contract a bacterial infection of the skin. Other complications that can result from chickenpox include viral pneumonia, bleeding problems, and infection of the brain (encephalitis).

Before the introduction of a vaccine, approximately 10,600 people were hospitalized and 100 to 150 died as a result of chickenpox in the U.S. every year. Vaccination became routine practice in the U.S. in 1995, and there are now two live, attenuated VZV-containing vaccines available for use. Recent studies have shown that in children, two doses of the chickenpox vaccine is 98 percent effective in preventing infection, compared with 86 percent effectiveness for a single dose. Recommendations from the Centers for Disease Control and Prevention and the American Academy of Pediatrics indicate that children should receive their first shot at 12 to 15 months, and the second at four to six years to ensure the maximum benefit. While a reported 15 to 20 percent of vaccinated individuals do still become infected with chickenpox if they are exposed to it, their condition is significantly milder and lasts for a shorter period of time.

By increasing awareness about the importance of vaccination, it may be possible to further decrease rates of infection and complications associated with chickenpox. Vaccination against chickenpox and other childhood illnesses can not only protect the individual receiving the vaccination, but can help to protect individuals who may not be able to receive vaccinations due to health conditions by contributing to the herd immunity of their community



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Monday, August 15, 2011

On the Importance of Blood Donation

According to World Health Organization estimates, a country’s basic requirements for safe blood could be met if one percent of that nation’s population donated blood. The WHO reports that 65 percent of all blood donations are made in developed countries, home to just 25 percent of the world’s population, and in some regions access to safe blood is limited. By ensuring that individuals have an understanding of the blood donation process and the importance of donating, it may be possible to ensure that blood supplies are available able to meet the need.

Image by Deborah Ervin
Blood donation has advanced significantly since the first blood transfusion involving a human being was performed in 1667, however the need remains. A reported one in seven people entering a hospital needs blood, and just one pint of blood – the amount obtained during a standard donation procedure – can save up to three lives. Each year, nearly 5 million people in the United States receive life-saving blood transfusions. During surgery, following an accident, or due to a disease or medical condition, individuals may require whole blood or blood components. Whole blood is the most common type of blood donation, during which approximately a pint of blood is given and the blood is then separated into its components. Both platelets and plasma are collected using a process called apheresis, during which the donor is hooked up to a machine that collects the desired blood component and then returns the rest of the blood to the donor. A double red blood cell donation in which only the red blood cells are collected also utilizes apheresis.

In order to be eligible to donate blood an individual must be in good health, at least 17 years old, at least 110 pounds, and able to pass the physical and health history assessment. In addition, before accepting the full donation, the level of iron is tested in a small sample of blood. All donated blood and blood components are subjected to a number of tests to ensure that they are free of bloodborne diseases such as hepatitis, HIV, and syphilis. Blood is also tested to determine the blood type (A, B, AB, or O) and Rh factor (either positive or negative) to ensure that it will be provided to compatible donors. Anyone in need of blood can receive type O red blood cells, and individuals with type AB blood can receive any blood type – thus individuals with type O blood are called “universal donors” and those with type AB blood are “universal recipients.”

Despite the need to maintain an adequate blood supply and the simplicity and safety of the blood donation process, reports indicate that younger individuals say they are “too busy” or “too scared” to give blood, and one in five donors under 30 have stopped donating. An estimated 38 percent of the U.S. population is eligible to donate blood, less than 10 percent donate annually.

Though blood components can be stored – red blood cells for 42 hours refrigerated or up to 10 years frozen, platelets at room temperature for five days, and plasma for up to a year frozen – researchers continue to work to develop a viable synthetic alternative to donated blood. By encouraging people to donate blood and working to find a synthetic blood alternative, it may be possible to ensure that the available blood supply meets the need.

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Monday, August 1, 2011

Malnutrition Worldwide

Estimates indicate that 925 million people – more than one in every seven worldwide – are undernourished, and 98 percent live in the developing world. Malnutrition develops when the body does not have the correct amounts of certain key vitamins, minerals, and nutrients to maintain organ function and healthy tissues. In areas affected by drought or other natural disasters, food supplies may be extremely limited, and increases in the number of malnourished individuals may be seen. By exploring new farming techniques and working to ensure that aid is provided in the affected nations, it may be possible to reduce rates of malnutrition.



Two-thirds of malnourished individuals are concentrated in seven countries: Bangladesh, China, the Democratic Republic of Congo, Ethiopia, India, Indonesia, and Pakistan. Other nations, particularly those in regions affected by drought, are also facing massive food shortages and increasing rates of malnutrition. In the Horn of Africa, a reported 10 million people including children and people with disabilities have been affected by the recent drought in this region – the most severe drought in the area in the past 60 years, which has interrupted food production. UN reports show that those who currently do not have access to a reliable source of food include an estimated 3.2 million people in Ethiopia, 3.5 million in Kenya, 2.5 million in Somalia, 600,000 residents of north-eastern Uganda, and 120,000 individuals in Djibouti.

Children are at a particularly high risk of becoming malnourished. World Health Organization estimates indicate that malnutrition contributes to more than one-third of all child deaths worldwide and the United Nations Children’s Fund approximates that 480,000 children in Somalia, Kenya, and Ethiopia will be severely malnourished this year – a 50 percent increase over last year’s figure. Mark Bowden, the UN humanitarian coordinator for Somalia, notes that the nation is currently facing “the highest rate of malnutrition in the whole of Africa, [and] more than 30 percent of children are suffering from global acute malnutrition.” Many malnourished children can be treated through the administration of calorie-dense, nutrient-rich foods including Ready-to-use Therapeutic Food (RUTF). Though RUTF is still not available in some regions, it based on peanut butter and dried skimmed milk and provides sufficient nutrient intake for complete recovery from malnutrition, and can be stored for three to four months without refrigeration, even at tropical temperatures.

According to UN reports, world food production will need to increase by up to 100 percent by 2050 in order to sustain 9 billion people, the expected global population. In addition to utilizing sustainable farming techniques, some experts have suggested the introduction of “super wheat” – a crop that is more resistant to some types of fungus that can destroy crops. Further exploration of crop options and sustainable farming techniques could help to expand the food supply and help to reduce global rates of malnutrition.

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Monday, July 18, 2011

Medical Uses of Venom

Though the bites and stings of snakes and other creatures can be deadly, researchers have identified compounds and proteins in the venom of some species with potential medical applications. Treatments to slow the growth of some forms of cancer, alleviate chronic pain, and slow the progression of Alzheimer’s disease are in development, and experts are working to identify other possible applications for venoms and animal-derived toxins.



According to John Perez, director of the National Toxins Research Center at Texas A&M University-Kingsville, “Snakes use venom to alter biological functions, and that’s what medicine does too.” The venom of some snakes has been found to have antibacterial applications, as well as slowing cell growth, increasing nerve stimulation, and affecting blood thinning and clotting. Preliminary research has shown that a compound found in the venom of some snakes may be able to inhibit cancer cell migration and slow the growth of tumor cells. Moreover, the anti-clotting proteins that contribute to the lethalness of a snake’s bite have been studied for their possible application as medications for high blood pressure and anti-clotting drugs.

In addition to snake venoms, toxins from a number of other animals have also been found to have medical applications. The saliva of the Gila monster is being studied as a possible drug for the treatment of type 2 diabetes, and proteins which can inhibit or stimulate the growth of blood vessels have been identified within the venom of several amphibians. Naturally occurring and synthesized venom from cone snails are being examined as new treatments for pain, epilepsy, and incontinence. As is the case also in snakes, experts note that there are more than 500 species of cone snail, and that each is able to produce more than 100 unique toxins, all of which could have beneficial medical applications.

Toxins from a number of arachnids and insects have also been examined. Historically bee venom has been used to treat a number of ailments, and in recent years bee venom therapy (BVT) or apitherapy has been touted as a treatment for arthritis, chronic pain, migraines, and multiple sclerosis. Compounds found in scorpion venom which disrupt the growth and spread of invasive tumors have been investigated for possible applications in treating brain cancer. Venoms from spiders have also been studied and research is ongoing to determine if they could be utilized to prevent arterial fibrillation after a heart attack, to regulate and control blood pressure, or to treat erectile dysfunction.

With additional research, it may be possible to identify new treatments for cancer or even HIV/AIDS among the compounds in venoms and toxins. By working to better understand the wealth of resources of the world’s biodiversity, it may be possible to improve global health.

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Monday, July 4, 2011

HIV/AIDS Progress

In the 30 years since it was first identified, the global response to AIDS has achieved significant results. More people than ever before have access to treatment, allowing them to manage their condition, and according to the United Nations rates of new HIV infections are falling by nearly 25 percent. In spite of these successes, it is important that efforts continue to ensure that progress is made towards further improving treatment options and outcomes.



Since 1981, a reported 25 million people worldwide have died from AIDS and an additional 34 million are infected with HIV. According to a recent United Nations report, in the 33 worst-affected countries, the rate of new HIV infections fell by 25 percent between 2001 and 2009, and in India and South Africa, the countries with the largest populations of individuals living with HIV, new infections fell by 50 percent and 35 percent, respectively. According to Michel SidibĂ©, Executive Director of UNAIDS, through the use of antiretroviral therapy (ART), “AIDS has moved from what was effectively a death sentence to a chronic disease…Antiretroviral therapy is a bigger game-changer than ever before – it not only stops people from dying, but also prevents the transmission of HIV to women, men and children.”

A decade ago, half of the population of several nations in southern Africa were expected to die of AIDS-related causes, but as ART has become more widely available, the death rate is dropping. An estimated 6.6 million people in low- and middle-income countries were receiving ART at the end of 2010 – a nearly 22-fold increase since 2001. In spite of this increase, reports indicate that there are 16 million people worldwide living with HIV/AIDS who could benefit from these medications but many do not receive them. Even in the United States and other developed nations, individuals living with HIV/AIDS are frequently put on long waiting lists to gain access to these life-saving drugs as the supply is not able to meet the demand for them.

While expanded access to ART can help to improve the lives of individuals with HIV/AIDS and help to prevent new infection, a major gap in treatment still exists. Access to treatment for children is significantly lower than for adults, and only 28 percent of all eligible children were receiving treatment in 2009, compared with 36 percent for people of all ages. In addition, while the rate of new HIV infections globally has declined, the total number of individuals with HIV remains high and certain groups, including women of reproductive age, remain at increased risk of infection. By ensuring that antiretroviral medications and education and treatment programs are widely available, it may be possible to further decrease the number of new HIV/AIDS infections worldwide as researchers continue to work to track the spread of the disease and find a cure.



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Monday, June 20, 2011

On MRSA Infections Worldwide

Methicillin-resistant Staphylococcus aureus (MRSA) infection has become increasingly common in recent years, due in large part to overuse of antibiotics. According to a 2007 report in Emerging Infectious Diseases, a publication of the Centers for Disease Control and Prevention (CDC), the average number of MRSA infections doubled nationwide between 1999 and 2005 – from 127,000 to 278,000. During the same period, the number of annual deaths from MRSA infection increased from 11,000 to more than 17,000. By increasing awareness about the risk factors associated with and steps that can be taken to avoid MRSA infection, it may be possible to reduce or eliminate its spread.



MRSA infection is caused by a strain of Staphylococcus (staph) bacteria that has become resistant to the antibiotics commonly used to treat staph infections, which include methicillin and penicillin. Generally, MRSA is spread through skin-to-skin contact, openings in the skin (cuts or abrasions), contact with contaminated surfaces, crowded living conditions, or poor hygiene. MRSA frequently manifests first on the skin as a reddish rash with lesions resembling pimples which may begin to drain pus, or lead to cellulitis, abscesses, and impetigo. In addition, the initial skin infection can spread to almost any other organ in the body, resulting in more serious symptoms and potential complications.

Designations are made between types of MRSA infection based on the location where the infection took place. Hospital-acquired MRSA (also called health-care-acquired, HA-MRSA, or HMRSA) remains one of the most common types of infection. Individuals who are hospitalized, those with invasive medical devices such as catheters, and those residing in nursing homes are at an increased risk of acquiring HA-MRSA. Community-acquired MRSA (CA-MRSA or CMRSA) is another common type of infection, and is seen most frequently in individuals participating in contact sports or those living in crowded or unsanitary conditions. While the average adult death rate among individuals with MRSA is estimated at five percent of infected patients, individuals with HA-MRSA are at an increased risk of experiencing complications including organ damage.

Dr. Marc Siegel, an associated professor of medicine at New York University, and others recommend an evaluation of the overuse of antibiotics by humans as well as in livestock as a means of eradicating MRSA and reducing drug resistance in other strains of bacteria. In addition, experts note the importance of good hygiene practices including washing hands frequently, keeping wounds covered with bandages until they have healed, and washing soiled clothes and sheets in hot water can help to prevent the spread of MRSA. The timely diagnosis of individuals infected with MRSA achieved through an analysis of a skin sample helps to better ensure not only treatment for the individual, but also a decreased risk of infecting others.

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Monday, June 6, 2011

On Non-Communicable Diseases

In 2008, non-communicable diseases (NCDs) accounted for 63 percent of all deaths worldwide. According the World Health Organization’s (WHO) recent Global Status Report on Non-communicable Diseases, without an intervention, NCDs are “projected to kill 52 million people annually by 2030." By informing the public about their risk, encouraging them to make healthy lifestyle changes, and improving treatment for individuals with NCDs, it may help to reduce the incidence of these diseases globally.



NCDs, which include diabetes and cancer, are defined as chronic conditions or diseases which do not result from an acute infectious process. The Centers for Disease Control and Prevention (CDC) report that half of all deaths in the U.S. each year are due to heart disease, cancer, or stroke. In addition to the incidence of NCDs in developed nations, a reported 80 percent of the 36.1 million NCD-associated deaths in 2008 occurred in developing nations. While NCDs can present a burden for any nation’s healthcare infrastructure, Dr. Margaret Chan, WHO Director General, notes that “for some countries it is no exaggeration to describe the situation as an impending disaster.”

Reports indicate that cardiovascular diseases account for the majority of NCD-related deaths, or 17 million annually, followed by cancer (7.6 million annually), respiratory disease (4.2 million annually), and diabetes (1.3 million annually). These four groups of diseases account for nearly 80 percent of all NCD deaths, and share four common risk factors: tobacco use, inadequate physical activity, harmful alcohol use, and poor diet. Almost six million people die as a result of tobacco use each year, and 2.5 million die from alcohol-related causes. In addition, lack of exercise and poor diet contribute to obesity, increasing individual’s risk of heart disease, stroke, and diabetes.

To lessen the impact that NCDs have on global health, the WHO has suggested that a number of measures be taken, including banning smoking in public places and promoting public awareness about the importance of diet and exercise. Encouraging individuals to make healthy lifestyle choices and providing them with information about how to improve their health, it may be possible to reduce the number of NCD-related deaths worldwide.



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