Category Archives: bacteria

Things to Know about Norovirus

bacteria, , ,

220px-Norovirus_4

The known viruses in the genus are all considered to be the variant strains of a single species called Norwalk virus. The viruses are transmitted by fecally contaminated food or water; by person-to-person contact; and via aerosolization of the virus and subsequent contamination of surfaces. Noroviruses are the most common cause of viral gastroenteritis in humans, and affect people of all ages.

Norovirus infection is characterized by nausea, forceful vomiting, watery diarrhea, and abdominal pain, and in some cases, loss of taste. General lethargy, weakness, muscle aches, headache, coughs, and low-grade fever may occur. The disease is usually self-limiting, and severe illness is rare. The virus affects around 267 million people and causes over 200,000 deaths each year; these deaths are usually in less developed countries and in the very young, elderly and immuno-suppressed.

Norovirus is rapidly inactivated by either sufficient heating or by chlorine-based disinfectants, but the virus is less susceptible to alcohols and detergents, as it does not have a lipid envelope.

Recently, (12/4/2013), Norovirus was inked to Rio and other Hotels in Las Vegas. Based on the results of positive laboratory testing, the Southern Nevada Health District has confirmed the illnesses it is currently investigating among a group of attendees of the National Youth Football Championship event as norovirus.

The health district is stressing the importance of practicing appropriate hygiene to limit the spread of norovirus. People who are sick should stay home from work or school until 72 hours after their symptoms have ended.

Norovirus is a self-limiting illness and symptoms resolve after a few days. The most serious complication can be dehydration, especially in children or older adults. It is important that people who are sick with norovirus, or any other gastrointestinal illness, stay home from work or school and avoid contact with other people.

Noroviruses are transmitted directly from person to person and indirectly via contaminated water and food. They are extremely contagious, and fewer than twenty virus particles can cause an infection (some research suggests as few as five). Transmission occurs through ingesting contaminated food and water and by person-to-person spread. Transmission can be aerosolized when those stricken with the illness vomit, and can be aerosolized by a toilet flush when vomit or diarrhea is present; infection can follow eating food or breathing air near an episode of vomiting, even if cleaned up. The viruses continue to be shed after symptoms have subsided and shedding can still be detected many weeks after infection.

Vomiting, in particular, transmits infection effectively. In one incident, a person who vomited spread infection right across a restaurant, suggesting that many unexplained cases of food poisoning may have their source in vomit. 126 people were dining at six tables in December 1998; one woman vomited. Staff quickly cleaned up, and people continued eating. Three days later others started falling ill; 52 people reported a range of symptoms, from fever and nausea to vomiting and diarrhea. The cause was not immediately identified. Researchers plotted the seating arrangement: more than 90% of the people at the same table as the sick woman later reported becoming ill. There was a direct correlation between the risk of infection of people at other tables and how close they were to the sick woman. More than 70% of the diners at an adjacent table fell ill; at a table on the other side of the restaurant, the rate was still 25%. The outbreak was attributed to a Norwalk-like virus (norovirus). Other cases of transmission by vomit were later identified.

Zombie Bacteria and Why We are in Trouble

bacteria, , , ,

bacteria

Humanity is engaged in an epic battle against fast-adapting and merciless predators. Not zombies, but by deadly pathogenic bacteria that have gained resistance to antibiotics.

Humans have co-existed with bacteria throughout our history. They live in our bodies from birth to death. It’s estimated that up to three percent of a typical human’s body mass is made up of symbiotic bacteria, which assist us with bodily functions like digesting food.

Most bacteria in the human body are kept in check by the body’s immune system. But bacteria are constantly evolving to survive and reproduce. Either the immune system successfully adapts to new threats, or the body risks being overrun. Sometimes the immune system will fail to respond allowing the bacteria to kill the host.

Before antibiotics were widely available, any accident, injury, or medical procedure that allowed pathogenic bacteria into the body was potentially deadly. One in nine skin infections was fatal. One in three cases of pneumonia led to death. Invasive surgeries including caesarean sections left the patient open to killer infections. Insect bites, burns, and blood transfusions frequently became a source of infection.

The discovery of the first antibiotic, penicillin, by Alexander Fleming in 1928 remains one of the high points in medical history. Antibiotics kill bacteria, which meant wounds were no longer death sentences.

One breeding ground for antibiotic-resistant bacteria is in farm animals. Low doses of antibiotics have been used since the 1950s to enhance growth. In the U.S., over 80 percent of all antibiotics are now used on farm animals. But low doses encourage resistance. Recent studies show that antibiotic-resistant bacteria have been found widely in farm animals.

The Centers for Disease Control and Prevention recently warned that drug-resistant bacteria kill at least 23,000 people annually in the U.S, and cost the health care system $20 billion per year.

However, pharmaceutical companies are not eager to produce new antibiotics. There are far more profitable drugs for pharmaceutical companies to throw money at, since antibiotics are usually single-serve drugs for humans, not long-term treatments.

Developing antibiotics is still expensive, and the antibiotics that we do have are still being over-prescribed for humans and doled out in sub-clinical doses to farm animals — both of which gives bacteria opportunities to develop resistance.

Microbes inhabit just about every part of the human body, living on the skin, in the gut, and up the nose. Sometimes they cause sickness, but most of the time, microorganisms live in harmony with their human hosts, providing vital functions essential for human survival.

Researchers found, for example, that nearly everyone routinely carries pathogens, microorganisms known to cause illnesses. In healthy individuals, however, pathogens cause no disease; they simply coexist with their host and the rest of the human microbiome, the collection of all microorganisms living in the human body.

This is wild. I read it several times, and it still says the same thing. “It appears that bacteria can pinch hit for each other. It matters whether the metabolic function is present, not which microbial species provides it.” Things in nature with no brains are amazingly smart.

Clostridium Perfringens Blamed in School Illnesses

bacteria, , ,

800px-Clostridium_perfringens

Clostridium perfringens (pər-frĭn’jənz), is a bacterium common among food-borne illness and tends to thrive in conditions that are slightly above room temperature. The spore-forming bacterium can also grow when foods are not properly cooled or are held at room temperature too long.

The dozens of Portland sixth-graders wracked with cramps, vomiting and diarrhea at an outdoor school excursion fell sick from a tainted batch of chuck roast, egg noodles and sour cream, the Multnomah County Health Department said Monday.

Health inspectors concluded that Clostridium perfringens was behind the mysterious illness that tormented 60 Portland Public School students at the Sandy River Outdoor School on Oct. 8 and rattled scores of parents.

C. perfringens is ever present in nature and can be found as a normal component of decaying vegetation, marine sediment, the intestinal tract of humans and other vertebrates, insects, and soil.

The gases form bubbles in muscle (crepitus) and the characteristic smell in decomposing tissue, whether vegetable, animal, or human.

The action of C. perfringens on dead bodies is known to mortuary workers as tissue gas and can be halted only by embalming.

Another recently reported case shows how this usually happens. A lady made a pot of chili which she served to her family. The pot was to big to fit in the refrigerator, so she left it out on the counter. The next night she reheated it and served it to her family. In three hours they were all in the hospital, including the dog which ate the leftovers.

Here’s the thing. The reheating (even at the proper temperature of 160 degrees), may have reduced the C. perfringens to safe levels, but the toxins produced by it as it enjoyed a very favorable growing environment, could no be removed even at 500 degrees.

Vibrio Vulnificus a Serious Sea Water Threat

bacteria, ,

vibrio

ST. PETERSBURG, Fla. Patty Konietzky thought the small purple lesion on her husband’s ankle was a spider bite. But when the lesion quickly spread across his body she knew something wasn’t right. After a trip to the hospital and a day and a half later, Konietzky’s 59-year-old husband was dead.

The diagnosis: vibrio vulnificus, an infection caused by a bacterium found in warm salt water. It’s in the same family of bacterium that causes cholera. So far this year, 31 people across Florida have been infected by the severe strain of vibrio, and 10 have died.

In Mobile, Ala., this week health department officials said two men with underlying health conditions were diagnosed with vibrio vulnificus in recent weeks. One of the men died in September and the other is hospitalized. Both men were tending to crab traps when they came into contact with seawater.

State health officials say there are two ways to contract the disease: by eating raw, tainted shellfish – usually oysters – or when an open wound comes in contact with bacteria in warm seawater.

While such occurrences could potentially concern officials in states with hundreds of miles of coastline and economies largely dependent on ocean-related tourism, experts say the bacteria is nothing most people should worry about. Vibrio bacteria exist normally in salt water and generally only affect people with compromised immune systems, they say. Symptoms include vomiting, diarrhea and abdominal pain. If the bacteria get into the bloodstream, they provoke symptoms including fever and chills, decreased blood pressure and blistering skin wounds.

But there’s no need to stop swimming in the Gulf of Mexico, says Diane Holm, a spokeswoman for the state health department in Lee County, which has had a handful of cases that included one fatality this year.

“This is nothing abnormal,” she said. “We don’t believe there is any greater risk for someone to swim in the Gulf today than there was yesterday or 10 years ago.”

There have been reports this year in Gulf states of other waterborne illnesses, but they are rare. In fresh water, the Naegleria fowleri amoeba usually feeds on bacteria in the sediment of warm lakes and rivers. If it gets high up in the nose, it can get into the brain. Cases have been reported in Louisiana, Arkansas and in Florida, including the August death of a boy in the southwestern part of the state who contracted the amoeba while knee boarding in a water-filled ditch.

Dr. James Oliver, a professor of biology at the University of North Carolina in Charlotte, has studied vibrio vulnificus for decades. He said that while Florida has the most cases of vibrio infection due to the warm ocean water that surrounds the state, the bacteria is found worldwide, generally in estuaries and near the coast.

“It’s normal flora in the water,” he said. “It belongs there.”

The vast majority of people who are exposed to the bacteria don’t get sick, he said. A few people become ill but recover. Only a fraction of people are violently ill and fewer still die; Oliver said many of those people ingest tainted, raw shellfish.

Oliver and Florida Department of Health officials say people shouldn’t be afraid of going into Florida’s waters, but that those with suppressed immune systems, such as people who have cancer, diabetes or cirrhosis of the liver, should be aware of the potential hazards of vibrio vulnificus, especially if they have an open wound.

Holm said nine people died from vibrio vulnificus in Florida in 2012, and 13 in 2011, so this year’s statistics aren’t alarming. What’s different, she said, was that victims’ families are speaking to the news media about the danger.