On Measles Worldwide

May 23, 2011

The World Health Organization reports that in 2008, there were 164,000 measles deaths globally, more that 95 percent of which were in low-income countries with weak health infrastructures. This rate equates to nearly 450 a day or 18 per hour. In recent years, targeted vaccination campaigns have greatly reduced the number of measles deaths each year, though in developing nations with weak health infrastructures complications or deaths related to measles infection are still not uncommon. By increasing awareness about the importance of vaccination and making vaccines available in regions where they are needed, the virus that causes measles could be eradicated.

Measles, also called rubeola, is a common and preventable childhood disease, also sometimes seen in individuals with compromised immune systems. Most frequently, infection is marked by a fever lasting a couple of days, followed by a cough, runny nose, and conjunctivitis.  Soon after, patients exhibit a rash on the face and upper neck, spreading down the back and trunk to the arms and legs. Reports indicate that 30 percent of people infected with measles will experience complications, ranging from ear infections to pneumonia. Further, one in every 1,000 people will develop inflammation of the brain. If left untreated, the complications associated with measles infection can be life threatening. In regions without widespread access to medical care, an estimated five percent of children die of measles-related causes.

According to William Schaffner, an infectious disease expert at Vanderbilt University School of Medicine, the measles virus infects more than 80 percent of unvaccinated people exposed to it. Though the transmission of endemic measles was declared eliminated in the U.S. in 2000, the disease remains common in other regions and can be imported by travelers. Reports from the Centers for Disease Control and Prevention (CDC) indicate that during 2008, nearly 90 percent of measles cases in the U.S. were either acquired abroad or linked to imported cases. While a safe and cost-effective vaccine is available, more than 20 million people are affected by measles each year and the majority live in developing nations and/or countries with low per capita incomes and weak health infrastructures.

Though measles outbreaks continue to be problematic in some developing regions, the World Health Organization reports that between 2000 and 2007, 576 million children were vaccinated against measles, resulting in a 74 percent decrease in measles-related deaths worldwide. By increasing awareness about the importance of vaccinations and ensuring that vaccines for measles are available, rates of infection, complications due to infection, and death could be even further reduced.

Click here to discuss this and other health topics in the iCons in Medicine Forums

Advertisements

West Nile Virus

August 23, 2010

West Nile virus (WNV) is an infection transmitted to humans and animals by mosquitoes which have fed on infected birds. According to the Centers for Disease Control and Prevention (CDC), between 1999 and 2008, 28,961 confirmed and probable cases of WNV were reported. Though 80 percent of individuals infected with WNV show no symptoms, approximately one in 150 develop severe illness with symptoms including high fever, vision loss, and paralysis. Though there is no vaccine or cure for WNV, it is important for individuals to have an understanding of how best to protect themselves from infection.

First identified in Uganda in 1937, WNV occurs when Culex pipiens mosquitoes feed on infected birds, which serve as vectors for the virus, and then pass the virus on to humans. WNV cannot be passed from one individual to another through close personal contact, and the primary method of transmission is through the bite of an infected mosquito. Mild infections (West Nile fever) are seen in approximately 20 percent of individuals, and are marked by symptoms including fever, headache, and body aches. Individuals with severe infections (severe West Nile disease) may experience inflammation of the brain (encephalitis) or of the brain and surrounding membranes (meningoencephalitis), and three to 15 percent of WNV infections result in death. According to CDC statistics, in 2009 there were a total of 663 cases of WNV in the United States, and 30 of these resulted in death.

The CDC indicates that WNV is an established seasonal epidemic in North America, beginning in the summer and continuing into the fall. In addition to documented cases in the United States, both sporadic cases and major outbreaks of encephalitis related to WNV have been reported in Africa, West Asia, Australia, Europe, and the Middle East. Recent reports have documented outbreaks in Greece and British Columbia, Canada; as well as in New York, Pennsylvania, and northwestern Indiana.

Like malaria, dengue, and other mosquito-borne illness, rates of WNV infection increase during periods of warm weather when mosquito populations are most active. Torrential rains in early summer and persistent high humidity in many regions of the United States have created the ideal breeding climate for mosquitoes. Experts recommend taking preventative measures to avoid infection including the “5 D’s”:

  • Dusk and Dawn – avoid being outdoors during these periods which are when mosquitoes are most active
  • Dress – wear clothing that limits exposed skin
  • DEET – use repellents containing DEET (picaridin and oil of lemon eucalyptus are other repellant options)
  • Drainage – eliminate areas of standing water in which mosquitoes lay eggs.

In addition, dead birds, particularly crows, which display signs of illness should be reported to authorities for proper disposal. As health officials continue to track outbreaks of WNV, individuals can take appropriate measures to limit their risk of infection and keep their community healthy.

Discuss this and other public health topics in the iCons in Medicine Forums


The Flu Vaccine

October 12, 2009

As new cases and concerns about seasonal flu and swine flu (H1N1) continue to spread worldwide, two vaccines have recently been made available. Both the nasal spray vaccine and injectable vaccine for seasonal flu have proven effective for specific portions of the population, however distribution is still slow. For the H1N1 (swine flu) virus, The Baltimore Sun reports, availability is still an issue and many areas have not yet received enough doses to meet the demand. While many in the developed world do not yet have access to the H1N1 vaccine, Dr. Bernadine Healy notes that the problem is even greater in the developing world. To help these nations fight the pandemic, the United States has agreed to donate 10 percent of its vaccination supply to the World Health Organization (WHO) – eight other nations will make similar donations.

Fantastic Image by Deborah Ervin

Inoculating individuals for both viruses is complicated by the time frame in which the vaccinations can occur. If one chooses nasal spray for both seasonal and swine flu, they must wait four weeks between doses, while if one is injected for one virus and uses nasal spray for the other, they can be administered together. Discovery Health reports that doctors recommend annual flu shots to lessen the chances of becoming ill. Individuals as young as six months can be inoculated, according to the Centers for Disease Control and Prevention (CDC) and side effects are reported to be minor. Because the virus used to make the seasonal flu vaccine is dead, it is not possible to contract flu from a flu shot, however one may expect a low-grade fever 8 to 24 hours following injection, a swollen or tender area around the injection site, a slight headache or chills within 24 hours.

The seasonal flu shot is an inactivated vaccine, and contains three influenza viruses – one A(H3N2) virus, one regular seasonal A(H1N1) virus (which differs from the 2009 H1N1 virus), and one B virus. The viruses used change annually based on international surveillance which track infection trends and scientists estimations about which strains will circulate during the year. In contrast to the flu shot, the nasal-spray flu vaccine contains a weakened but still living flu virus, sometimes called LAIV (live attenuated influenza vaccine). These nasal mists are approved for use in healthy individuals ages two to 49 who are not pregnant. In addition to nasal sprays, Discovery Health reports that researchers at Stanford University and the University of Alabama at Birmingham have been working with naked DNA in an effort to develop a vaccine that could be delivered via shampoo or dermal patch.

Three recent large-scale studies, including a study led by Dr. Arnold S. Monto of the University of Michigan, indicate that while the seasonal flu shot is more effective for adults and safe for women who are pregnant, the intranasal vaccine (nasal spray) is more effective at preventing flu in children. These studies showed 35 to 53 percent fewer cases of flu in children who were given the nasal spray vaccine than those who received injected vaccines. The Los Angeles Times reports that injectable vaccines prevent roughly 50 percent more seasonal flu in healthy adults than the nasal spray vaccines.

Due to the relative newness of the H1N1 vaccine, health authorities have implemented a number of tracking measures to ensure its safety. The Associated Press reports that Harvard Medical School scientists are working to link insurance databases covering 50 million people with vaccination registries to allow them to determine if people visit a doctor after being vaccination as well as the reason for the visit. Johns Hopkins University and the CDC are also working to ensure that any side effects are noted and addressed quickly. These efforts include emailing individuals who have been vaccinated recently to see how they are feeling (Johns Hopkins), and preparing take-home cards asking vaccine recipients to report any side effects to the nation’s Vaccine Adverse Event Reporting system (CDC). These measures are being undertaken as in the Internet-age, the Associated Press notes, one person updating their Facebook status to say that they got a flu shot and feel sick could cause a wave of similar reports.

Discuss This and Other Vaccination Matters in the iCons in Medicine Forums

Associated Press on the Nasal Spray Flu VaccineThe New York Times on CDC Side Effect Tracking Measures