Ebola Deuxième Partie: vaccin

This is the second installment in the Ebola Hemorrhagic Fever (see part 1 here), since there seems to be a bit of misinformation circulating. This is merely a swift breakdown of current research and doesn't address political issues regarding it. It's also a quick breakdown on how exactly vaccinations work.

To quickly recap, Ebola Hemorrhagic Fever is currently causing devastation in Sierra Leone, Guinea, and Liberia. With a death toll of over a thousand and climbing, and treatment of U.S. doctors and missionaries (CNN), everyone is calling for a vaccination.

And a quick recap of how vaccinations work. The body protects itself from disease via the production of antibodies by the immune system that target foreign"antigens" (germs). The body remembers these antigens and gives a much faster response if there is a repeat infection. The immune system, however, can sometimes be too slow to respond to prevent sickness. That's where vaccines come in. Vaccinations are effective because they contain antigens that have been that have been killed or weakened to the point where they don't cause disease, but still allow antibodies to develop against them. This way if infection does occur, the body already has memory of it and can respond much faster so sickness doesn't occur.

There is a promising filovirus vaccine under development for Ebola Hemorrhagic Fever based on recombinant vesicular stomatitis virus. This type of vaccine has shown to be 100% effective against Marburg virus and 3 species of the Ebola virus in nonhuman primates. There are caveats, though; protection is only good for 28-35 days after a single injection, and this hasn't undergone human trials.

Correction from reliable sources is always appreciated.

Goodbye (to blogger)

Thank you all for your interest and support in making this blog go "viral". I hope you enjoyed reading about the dark (and gross) side of biology as much as I had writing it. But fear not (or do), things that go bump in your body will be bumping in another host. Stay tuned, stay healthy, and keep your hands clean and food thoroughly cooked.

Chiku-chiku-ngunya

Countries & territories where chikungunya
cases have been reported as of July 15th, 2014.
Does not include countries or territories with only imported cases.
Map courtesy of CDC

Since 2006, the U.S. has average 28 chikungunya (pronounced \chik-en-gun-ye) cases a year in travelers returning from countries where the disease is common, and the mosquito-borne virus was first identified in the Western Hemisphere seven months ago. But on July 17th, 2014, a man in Florida was the first to locally acquire hte disease in the continental U.S.

Transmission electron micrograph
of  numerous chikungunya virus
particles. Image courtesy of CDC

Chikungunya, a single-stranded RNA virus from the Togaviridae family, is transmitted via Aedes aegypti and Aedes albopictus mosquito bites in humans.  Most people infected with the chikungunya virus will develop symptoms-which are primarily fever and joint pain-three to seven days after being bitten by an infected mosquito.  Other symptoms include headache, muscle pain, joint swelling, or rash.  It's not often a fatal disease, but the symptoms can be severe and disabling. Most recover within a week, although the joint pain can last for months.  The highest risk groups are newborns, adults above the age of 65, and those with high blood pressure, diabetes, or heart disease.  The good news is once a person has been infected, they are likely protected from future infections.

Aedes aegypti & Aedes albopictus.  Courtesy of CDC

Courtesy of CDC

Courtesy of CDC

The course of chikungunya is unknown, but CDC officials believe it will behave like the dengue virus, where imported cases have resulted in sporadic local transmission but not widespread outbreak.  There is no vaccine or targeted treatment for the chikungunya virus. To preven infection, the use of A/C, window and door screens or mosquito bed netting, DEET/picaridin/IR3535/oil of lemon eukalyptus/para-menthane-diol products, and long-sleeved shirts and long pants.  It is also recommended to empty standing water from containers like flower pots and buckets to reduce the number of mosquitoes outside the home.  The CDC and the Florida Department of Health aremonitoring for additional cases and consulting the public on ways to prevent chikungunya from spreading.  

Anthrax-We are our own worst enemy

Figure courtesy of the CDC

Last week we talked about how vials of smallpox were found in a FDA laboratory, showing that even labs are guilty of having that old, over-crowded stockroom that's in every office complex. And here's another reminder that labs are as prone to human error and politics as any office-the CDC has released an after-action report regarding employees' exposure to anthrax. For those that are just tuning in, extracts and cultures of Bacillus anthracis (anthrax) in the Bratt BSL*-3 lab were sent to different laboratories on June 6th and June 12th with a potential for aerosolization.

Figure courtesy of CDC

This is not the first time B. anthracis has been in the news. The bacteria is a serious infectious disease that can be found naturally in soil and commonly affects domestic and wild animals. It is rare in developed nations where veterinary public health programs vaccinate livestock against it. Those few who get sick from it are infected from breathing in the spores, eating food or drinking contaminated water, or from spores in a scrape on the skin. Other members of the Bacillus genus (and there are several) can be non-pathogenic or pathogenic, but are none are as virulent as anthrax.

Photomicrograph of Bacillus anthracis using Gram-stain technique
Image courtesy of CDC

The type of illness depends on the type of anthrax. Cutaneous anthrax causes a group of small blisters or bumps that may itch and/or a painless skin sore with a black center. Inhaled anthrax spores result in fever/chills, chest discomfort, shortness of breath, confusion or dizziness, cough, nausea/vomiting/stomach pains, headache, drenching sweats, extreme tiredness, and body aches. Gastrointestinal anthrax symptoms are fever/chills, swelling of neck or neck glands, sore throat, painful swallowing, hoarseness, bloody diarrhea, headache, face flush, red eyes, stomach pain, fainting, and swelling of the abdomen. Injected anthrax is similar to cutaneous, but quicker and harder to recognize and treat.

While the incident was unfortunate, none of the staff became ill from anthrax and it triggered the development of new safety protocols. And, of course, none of it escaped the CDC.

Figure Courtesy of CDC

*BioSafety Level: the application of precautions that reduce a laboratorian's risk of exposure to infectious microbes and limit work space contamination. There are four levels, and each has specific containment controls of biological agents based on infectivity, severity, transmissibility, and work conducted.

Big things come in small poxages

On July 1st, employees at a laboratory on the National Institutes of Health Bethesda campus found vials of smallpox from the 1950s while preparing for the lab's relocation to the FDA's main campus. This laboratory had been transferred from NIH to FDA in 1972, and the FDA has operated laboratories located on the NIH campus since then. The vials themselves have since been secured in the CDC's high-containment facility in Atlanta, and are currently undergoing testing for viability. Upon completion, if the samples are viable, they will be destroyed and, as per protocol, the World Health Organization has been invited to witness. Currently, there are two WHO-designated repositories for smallpox, the CDC and the State Research Centre of Virology and Biotechnology in Novosibirsk, Russia. The CDC's Division of Select Agents and Toxins is investigating the history of how these samples were originally prepared and stored in the FDA laboratory.

Gutstein Methyl Violet stain of smallpox skin lesion.
Viral particles stain light to dark violet
Image courtesy of CDC

Smallpox is a highly contagious and sometimes fatal infectious disease that has no specific treatment, only a vaccination. There are two forms of the virus, variola major (the most severe and most common) and variola minor, both of which are only hosted in humans. Variola major is divided into four types, ordinary (the most common), modified (occurring in those previously vaccinated), flat, and hemorrhagic (both rare and very severe). Variola major has on average a fatality rate of about 30%, but the last two are usually fatal.

Smallpox vs. chickenpox
rash distribution
Image courtesy of CDC

Direct and prolonged face-to-face contact is required to spread smallpox, but can be spread through direct contact with infected body fluids or contaminated objects. Symptoms begin with an onset of fever, malaise, head, and body aches with occasional vomiting. Small red spots on the tongue and mouth then emerge, spreading to the face and the rest of the body and lastly to the feet. This rash then becomes raised bumps filled with a thick, opaque fluid with a depression in the center. The bumps then become pustules-sharply raised, round and firm, which then begin to scab and eventually fall off, leaving pitted scars. The duration of the entire disease may be several week, but the person is most contagious for the week following the rash outbreak.

The disease is now eradicated thanks to a worldwide vaccination program. The last case in the U.S. was in 1949 and the last one globally was in Somalia in 1977. Routine vaccination was discontinued after smallpox's eradication.

Go Go Gonorrhoeae

Antibiotic resistance is nothing new in the world of health care. Most deaths related to antibiotic resistant bacteria are in health care settings, such as hospitals and nursing homes. However, there is an organism that is causing concern for those outside of these environments, and that is Neisseria gonorrhoeae (also known as "the clap").

3D computer-generated image
of drug-resistant N. gonorrhoeae
Image courtesy of CDC

N. gonorrhoeae is one of several species of the genus Neisseria, which contains both normal flora and pathogens of humans and animals. N. gonorrhoeae is a common sexually transmitted disease that causes infection in the genitals, rectum, and throat, and can also be spread to an infant from an infected mother during childbirth. Symptoms of infection include a burning sensation when urinating, a yellow, green, or white discharge from the penis, and occasionally painful or swollen testicles. Most infected women are asymptomatic, and those that have symptoms are often mild and mistaken for a bladder or vaginal infection. All infected women are susceptible to serious complications, characterized by painful or burning sensation when urinating, increased vaginal discharge, and vaginal bleeding between menstrual cycles. Signs of symptomatic rectal infections are discharge, anal itching, soreness, bleeding, and painful bowel movements.

Figure Courtesy of CDC

N. gonorrhoeae is becoming a health concern because it has developed resistance to sulfonilamide, penicillin, tetracycline, and fluoroquinolone (ex. ciproflaxin) antibiotics. N. gonorrhoeae is readily able to develop resistance, which would complicate treatment, since there are few options left that are simple, well-studied, well-tolerated, and highly effective. The current recommended therapy is cephalosporin ceftriaxone plus either azithromycin or doxycycline. N. gonorrhoeae is under surveillance by the Gonococcal Isolate Surveillance Project (GISP), established in 1986.

Figure courtesy of CDC

Clinicians are asked to report any N. gonorrhoeae specimen that demonstrates decreased cephalosporin susceptibility and any cephalosporin treatment failure. Outside the U.S., ceftriaxone-resistant N. gonorrhoeae have already been reported in Japan and South Africa.

La Fièvre Hémorragique Ebola

One of the worst outbreaks of Ebola Hemorrhagic Fever (Ebola HF), a severe and often fatal disease in humans and other primates, is occurring in Guinea, Sierra Leone, and Liberia. Between the three, 338 fatal cases have occurred, with several more laboratory confirmation and reports in other districts.

Ebola Hemorrhagic Fever Distribution Map
Image Courtesy of CDC

Colorized Transmission Electron Micrograph
of Ebola Virus virion
Image courtesy of CDC

Ebola HF is a virus within the family Filoviridae, genus Ebolavirus. There are five subspecies of the Ebolavirus family, four of which cause disease in humans: Ebola virus (Zaire ebolavirus), Sudan virus (Sudan ebolavirus), Taï Forest Virus (Taï Forest ebolavirus, formerly, Côte d'Ivoire ebolavirus), and the Bundibugyo virus (Bundibugyo ebolavirus).

First discovered in the Democratic Republic of the Congo near the Ebola River in 1976, outbreaks have been sporadically occurring in endemic regions. The natural reservoir, or host, of ebolaviruses is still unknown, although native bats are strongly suspected due to the nature of similar viruses. Besides from the animal host, the virus can be transmitted between people by direct contact with the blood or secretions (i.e. urine, feces, saliva) of an infected person or exposure to contaminated objects. Those most often infected are families and friends that come in close contact while caring for the ill, or those in health care settings where appropriate protective equipment (masks, gloves, gowns, etc.) aren't worn and proper cleaning and disposal of medical instruments isn't performed.

Life Cycle of the Ebolavirus
Image courtesy of CDC

Symptoms of the virus may appear 2 to 21 days after exposure, although 8 to10 days is most common. Symptoms of those infected include fever, headache, joint and muscle aches, weakness, diarrhea, vomiting, stomach pain, and lack of appetite. Some may experience a rash, red eyes, hiccups, cough, sore throat, chest pain, difficulty breathing and swallowing, and bleeding inside and outside the body. The reasons behind why some get sick and are able to recover while others are not is not fully understood, although fatalities are usually in those who haven't developed a significant immune response to the virus at the time of death. Diagnosis of this disease is difficult because early symptoms of red eyes, skin rash, fever, and headache also occur in more common diseases, and treatment is supportive (balancing patients' fluids and electrolytes, maintaining oxygen status and blood pressure, and treating for any other complicating infections).

Ebola HF is unlikely to spread to nations outside of the African continent. The only reported instance of Ebola transmission in the US was Ebola-Reston virus (the fifth subspecies that doesn't cause disease in humans) from imported research monkeys in 1990, and it didn't result in clinically apparent disease.

California Cough

A new epidemic has been sweeping across the pacific coast, and it's not a new disease. More than 800 new cases of Bordetella pertussis, or "whooping cough" have been reported in the last two weeks, and as of June 10th, there have been 3458 cases of pertussis reported to California Department of Public Health in 2014, more than in all of 2013. (Source: CDPH)

Gram-stained photomicrograph of
Bordetella pertussis bacteria
Image courtesy of CDC

Bordetella pertussis is a respiratory illness that starts with cold-like symptoms including a runny nose and possible mild cough or fever. After 1-2 weeks, severe and distinct coughing fits develop and can last for more than 10 weeks, causing vomiting and fatigue.  In infants, the disease can manifest in apnea, or a pause in breathing pattern.  It's also particularly dangerous for babies, with about half of infected infants needing hospitalization. The pertussis bacterium attaches to small hair-like extnesions called celia which line the upper respiratory symptoms.  It releases toxins that damage the cilia and cause inflammation.  It is a very contagious human disease that is spread by droplet transmission.  No vaccine is 100% effective, so during community circulation the infected should be avoided.

The epidemic isn't all due to an anti-vaccination movement.  Pertussis is actually cyclical, with peaks every 3-5 years.  Over the past 20-30 years. peaks have been getting higher and overall case counts rising, due to a viaretiy of factors including increased awareness, improved diagnostic tests, better reporting, more circulation of hte bacteria, and waning immunity. Also, the vaccine used in the US, the acellular pertussis vaccine (DTaP), which has fewer possible side effects, does not protect as long as the whole cell vaccine (DTP).

Even though this epidemic is not directly caused by anti-vaccination tendencies, vaccines are absolutely critical not only to protect against several dangerous and potentially fatal diseases but to protect those that are unable to receive them, such as those that are allergic to components in the vaccine delivery system, the immunocompromised, infants below vaccination age, and the elderly whose vaccines may have worn off with time.

Oh Noro!

"Food poisoning." "Stomach flu." The go-to reason for calling in "sick". Unfortunately, there are those that really should call out of work that aren't. Norovirus is the #1 leading cause of disease outbreaks from contaminated food in the U.S., 70% of which is caused by infected food workers.

Not all food poisoning is caused by norovirus (other germs and chemicals share the honor), and it's not related to the Haemophilus influenza (the long name for the flu). It does cause the inflammation of the stomach and intestines (acute gastroenteritis), leading to stomach pain, nausea, non-bloody, watery diarrhea, and acute-onset vomiting lasting for 24-72 hours. Some people present with a low-grade fever, headaches, and myalgias (body aches), and dehydration is the most common complication. It can be caught again and again, and can be serious for young children and older adults.

Transmission electron micrograph of norovirus virions
Image courtesy of CDC

Noroviruses, previously called Norwalk-like viruses, are a group of non-enveloped, single-stranded RNA viruses of the family Calciviridae. Three of the six currently recognized norovirus genogroups, GI, GII, and GIV, infect humans. The most common type causing infection since 2002 is the variants of the GII.4 genotype. The virus is shed through feces once symptoms begin, and continue to do so for 2 weeks or more after recovery (although this does not necessary mean they are contagious).

Norovirus can be spread by contact with an infected person, touching contaminated surfaces, or eating or drinking contaminated foods or water. It has a tendency to spread quickly in closed places like daycare centers, nursing homes, schools, and cruise ships. It is a hardy virus, able to stay on food at freezing temperatures and on kitchen surfaces and utensils for up to two weeks.  It's also resistant to many common disinfectants and hand sanitizers, and only requires 18 viral particles to make you sick.



There is currently no medicine that can treat norovirus, but is manageable with plenty of liquids (not cafffinated or alcoholic beverages) to replace fluid lost from vomiting and diarrhea.  It is preventable through sanitation techniques for both the general public and food service employees, outlined in the infographic below.

To and Fro and In-between (or Ew! I don't want to touch it!)

This is the second installment of the series "To and Fro and In-between" covering getting sick while traveling in an airplane.  Last week's installment was getting sick through breathing the same air as that coughing passenger.  This week is about what you can catch through touch, or direct contact transmission.

Kiril Vaglenov of Auburn University recently presented to the the American Society of Microbiology his research regarding the lifespan of certain bacteria on airplane cabin surfaces.  He and his colleagues tested the ability of two pathogens, MRSA (methicillin-resistant Staphylococcus aureus) and E. coli 0157:H7 (Escherichia coli) on common surfaces in airplanes.  Materials for the armrest, plastic tray table, metal toilet button, window shades, seat pocket cloth, and leather were inoculated with the bacteria and exposed to typical airline conditions.  MRSA lasted 168 hours on the seat-back pocket while E. coli O157:H7 survived 96 hours on the armrest material.  Current cleaning practices of aircraft according to the World Health Organization include cleaning the aircraft interior as time permits, with priority given to litter and dry waste removal and cleaning of the toilet compartments and galleys.

E. coli O157:H7
Image courtesy of CDC

E. coli is a large and diverse group of bacteria.  Most strains are harmless, and some even live in human and animal intestinal tracts.  However, the O157:H7 strain is considered pathogenic because it produces a toxin called Shiga, causing stomach cramps diarrhea that is often bloody, vomiting, and possible low grade fever.  It is transmitted through contaminated water or food, and is the strand that is most common in North America during E. coli "outbreaks" of infections.

MRSA bacteria
Image courtesy of CDC

MRSA stands for methicillin resistant Staphyloccous aureus, a type of staph bacteria that is resistant to several antibiotics.  MRSA can cause skin and other infections, as well as severe problems in healthcare settings such as bloodstream infections, pneumonia, and surgical site infections.  It is spread though direct contact with an infected wound or sharing personal items that have touched skin.  Infection risk can be increased by certain activities or places that include crowding, skin-to-skin contact, and shared equipment or supplies. Symptoms begin as a bump or infect area that might be red, swollen, painful, warm to the touch, full of pus or other drainage, and may be accompanied by a fever.  Two in every 100 people are MRSA colonizers, meaning they carry it as part of their natural bacteria.

Further research into direct contact transmission on airplanes is going to involve testing other human pathogens including those that cause tuberculosis, as well as exploration of effective cleaning and disinfection strategies.  Different surfaces that have antimicrobial properties will be tested to see if they will reduce the persistence of pathogenic bacteria in the cabin.

Until more is known about what can spread by just touching the armrest, avoid touching your face during the flight and wash your hands before eating (and don't eat the food that fell on the tray table).

Source: American Society for Microbiology

To and Fro and In-between (or Help! I'm afraid to breathe!)

Besides diseases in other countries, every traveler has another fear-being trapped in an aircraft cabin for several hours with the passenger that can't stop coughing. Every year over 1 billion people travel by commercial airways from all over the world, and this number is expected to double over the next 20 years.  But how likely are you to get sick from that passenger who didn't change their flight (or at least their seat next to you)?

Droplet transmission.
Image courtesy of the CDC.

The answer is a complex one because there are multiple ways to get infected. One method of infection (and the one everyone worries about on flights) is droplet or airborne transmission.  This occurs by inhaling small particles containing infectious agents that remain infective over time and distance. 

Surprisingly, the risk of infection on an airplane via this route is lower than you might think.  All commercial aircrafts (and a few modified older planes) recirculate 10-50% of the air in the cabin and mix in the air from outside.  The recirculated air passes through a series of filters 20-30 times per hour.  In newer-model airplanes, high-efficiency particulate air (HEPA) filters capture 99.9% of particles 0.1-0.3 um in diameter.  Also, the air isn't forced up and down the length of the airplane, but rather flows transversely across the plane in limited bands (saving you from that coughing passenger several rows ahead).  

Seating diagram for passengers
exposed to measles, rubella, or TB.
Image courtesy of the CDC.

If the sick passenger is sitting next to you, the risk is about the same as sitting next to any other ill person (the odds of infection

change depending on what is making the person sick).  The good news is that there is protocol in place should the disease they carry be of public health concern.   Flight contact investigations are performed for infectious tuberculosis (TB), measles, rubella (German measles), pertussis (whooping cough), and meningococcal disease (meningitis).  CDC protocols are in place to identify passengers who may have been exposed.  Exposed passengers will be contacted by their state and local health departments or ministries of health to inform them about their exposure and what to do.

So take a deep breath, relax, and enjoy the flight (and try not to think to hard about what you might be touching...)

Dengue World Cup

Endemic Regions of Dengue Fever  
Image courtesy of the CDC

Dengue fever infects approximately 400 million people annually and is a leading cause of illness and death in the tropics and subtropics.  It was first documented in the 1950s in

Aedes aegypti mosquito, a dengue virus vector.
Image courtesy of the CDC

the Philippines and Thailand and remained there until 1981, when large numbers of Dengue Hemorrhagic Fever were reported in the Caribbean and Latin America, including Puerto Rico, the U.S. Virgin Islands, U.S.-affiliated Pacific Islands and the British Virgin Islands. Yet only recently has it begun making headlines, thanks to the 2014 FIFA World Cup in Brazil.  

Dengue fever has 4 virus types (DENV 1, 2, 3, and 4) and is spread by the Aedes mosquito in high population areas when rainfall is optimal for breeding.  It is a bloodborne virus, so transmission can also occur through exposure to infected blood, organs, and tissues, as well as through vertical transmission (mother-to-neonate).  Dengue hemorrhagic fever is a more severe form of dengue fever, and risk factors include having a previous infection, being younger than 12, female, or Caucasian. 

Dengue fever may cause high fever, severe headache, eye pain, joint pain, muscle and/or bone pain, rash, mild bleeding in the nose or gums, petechiae, easy bruising and/or a low white blood cell count.  Warning signs to watch for 3-7 days after fever temperature declines include severe abdominal pain or persistent vomiting, red spots or patches on the skin, bleeding from the nose or gums, vomiting blood, black stools, drowsiness or irritability, pale, cold, clammy skin, or difficulty breathing.  The signs and symptoms of DHF are consistent with dengue fever, including the fever decline.  In DHF, this decline marks the beginning of a 24-48 hour period where capillaries become excessively permeable, causing ascites and pleural effusions.  Without prompt, appropriate treatment, symptoms can progress to circulatory system failure and shock, and possibly death.

Currently, there is no vaccination or specific medication for treatment of dengue fever or dengue hemorrhagic fever.  Symptoms are manageable with analgesic pain relievers (ex. acetaminophen and paracetamol), rest, plenty of fluids to prevent dehydration, and consulting a physician.  DHF can be effectively treated with fluid replacement therapy with an early clinical diagnosis (this generally requires hospitalization).

There is good news on the horizon.  Sanofi Pasteur, a multinational pharmaceutical company, is

in Phase 3 clinical trials of the CYD dengue vaccine. The purpose of the study is to assess the efficacy of the CYD dengue vaccine after 3 vaccinations at 0, 6, and 12 months in preventing symptomatic virologically-confirmed dnegue cases, regardless of the severity, due to any of the four virus types in children aged 2 to 14 years.  It is difficult to determine at this time when this vaccine would be available to the public.  For more information, please visit www.clinicaltrials.gov 

Prevention

To prevent dengue fever when present in endemic regions, eliminate containers that hold water in and around the home to prevent breeding. Wear mosquito repellent indoors and outside (the higher the DEET content, the better) at all times and long sleeves and pants.  Windows and door screens should be secure and without holes, and use air conditioning where possible.

For a more technical review: Dengue Detection

A New Respiratory Tract Infection

MERS-CoV particles under negative stain electron microscopy
Virions contain club-like projections emanating from
 membrane. Image courtesy of CDC

    

Human serum antibodies react with MERS infected  Vero cells,
indicating infection.  Image courtesy of CDC

There's a new kid on the block among respiratory tract infections, and it goes by MERS, or Middle East Respiratory Syndrome, first confirmed in Saudi Arabia in 2012.  Symptoms of infection include fever, cough, and shortness of breath, all signs of severe acute respiratory illness.  Its mortality rate is greater than 30% for those infected. 

This syndrome is caused by a coronavirus called MERS-CoV.  Coronaviruses, named for their crown-like morphology.  They are common viruses and usually cause mild to moderate upper-respiratory tract infections. There are three main subgroups and a recently-assigned new sub group, alpha, beta, gamma, and delta, respectively. 

 The ones that affect humans are alpha 229E and NL63, and beta OC473, HKU1, and SARS-CoV (responsible for severe acute respiratory syndrome prior to 2004).  Typical symptoms of non-SARS coronaviruses are coughing, runny nose, sore throat, and fever.  It may also cause lower-respiratory tract infections in the elderly and immunocompromised

Why is this virus important? Because like SARS, it has left its origin country and infected two U.S. patients that had traveled to Saudi Arabia--one on May 2nd, 2014 and a second one May 11th, 2014.  The first patient has made a full recovery and the second is currently hospitalized but recovering. Don’t panic--at this time there is a low risk to the general American public at this time and those that had contact with the two infected are being contacted.  

For more information, please visit: CDC.gov

For a more technical review of this topic: MERS-CoV Interim Guidelines

Update 5/15/15: healthcare workers exposed to the MERS patients have been sent home for 14 days after two showed flu-like symptoms. Neither are confirmed MERS patients as of now. 

Resource: CNN.com