2018-12-18

[Science News] Are e-cigarettes a safe alternative to smoking? How e-cigarettes work?


[Science News] Are e-cigarettes a safe alternative to smoking?

What are e-cigarettes?
An e-cigarette is a long tube that usually resembles a cigarette, a cigar, a pipe, or a pen. Most are reusable, with replaceable and refillable cartridges, but some are disposable.

The first patent for a "smokeless, non-tobacco cigarette" was requested by Herbert A. Gilbert in 1963, but the current device did not appear until 2003.

The e-cigarette as we know it was invented by Hon Lik, a Chinese pharmacist, working for Golden Dragon Holdings, now known as Ruyan. The company started exporting into major markets in 2005 to 2006. There are now over 460 different brands on the market.

How they work?

Risks?
While e-cigarettes may help some people quit, there is growing evidence that vaping may be harmful in some cases, and more harmful than avoiding smoking altogether.

Here are 10 reasons why the authorities are concerned:

1. Most e-cigarettes contain nicotine, which is addictive and triggers changes in the adolescent brain. It is hazardous during pregnancy as it can affect fetal development.
2. The aerosol contains solvents, flavorings, and toxicants, which the Surgeon General describes as either "harmful" or "potentially harmful."
3. E-cigarettes expose the lungs to different substances. One of these is dicetyl, which can cause "popcorn lung," a severe and irreversible lung disease.
4. Potentially fatal poisoning has resulted from accidentally swallowing and from inhaling c-cigarette liquid.
5. People who seek to quit smoking will stop using conventional and medically monitored methods of doing so.
6. Those who use or who have used e-cigarettes are less likely to stop smoking altogether.
7. Teens who use e-cigarette products are more likely to start using regular tobacco as well.
8. Continued use of nicotine can make other drugs, such as cocaine, more pleasurable.
9. The flavorings, the marketing, and the concept that it is not harmful all tempt teenagers to start vaping. There is concern that this increases the chance that they will smoke conventional cigarettes later.
10. Second-hand smoking is not eliminated by vaping, as vaping releases carcinogenic emissions.

In addition, experimental use of vaping materials may put teens at higher risk.

The National Institute on Drug Abuse (NIDA) point to the practice of "dripping," which involves inhaling solutions that are dripped directly onto the heater coil, as one such risk practice. Reasons include "to produce a stronger throat hit."

News about this
Vaping among teens spikes, luring new generation of kids into tobacco use.
Originally published December 17, 2018 at 6:03 pm Updated December 17, 2018 at 6:32 pm By Karen Kaplan - Los Angeles Times (TNS)

From: https://www.seattletimes.com/nation-world/vaping-among-teens-spikes-luring-new-generation-of-kids-into-tobacco-use/

The proportion of U.S. high-school seniors who are vaping tobacco products nearly doubled in the past year, with more than 1 in 5 now saying they have vaped to get a hit of nicotine in the past 30 days, according to a new study.

The prevalence of nicotine vaping nearly doubled among 10th-graders as well, with nearly 1 in 6 using the electronic devices, researchers reported Monday in the New England Journal of Medicine.


The findings suggest that the total number of high-school students using tobacco surged by 1.3 million between 2017 and 2018. “This increase was driven solely by nicotine vaping,” the researchers wrote.

The figures are based on a nationwide survey of eighth-, 10th- and 12th-graders who participated in the Monitoring the Future study, which has tracked teen use of tobacco, alcohol, illicit drugs and other substances every year since 1975.


“The absolute increases in the prevalence of nicotine vaping among 12th-graders and 10th-graders are the largest ever recorded by Monitoring the Future in the 44 years that it has continuously tracked dozens of substances,” wrote a team led by Richard Miech, who leads the study at the University of Michigan’s Institute for Social Research.

When electronic cigarettes first took hold among U.S. teens nearly a decade ago, public-health experts fretted that the slick devices would lure a new generation of kids into tobacco use.

The new report vindicates their fears.

Makers of vaping devices say their products are intended for use by adults, particularly smokers who would like to cut back on regular cigarettes by switching to a less-toxic alternative.

Juul, the company that now dominates the market, says its mission is to create “a world where fewer people use cigarettes, and where people who smoke cigarettes have the tools to reduce or eliminate their consumption entirely, should they so desire.”


Unlike traditional cigarettes, which burn tobacco, e-cigarettes use a battery to heat a liquid that is inhaled in an aerosol form. That liquid usually contains nicotine along with a mixture of chemicals and flavorings. Juul’s starter pack includes “pods” with flavors like mango, mint and crème.

Other e-liquid flavors seemed to be squarely aimed at kids, with packages that resembled frosted cookies and sour candies.

The U.S. Food and Drug Administration (FDA) ordered online retailers to stop selling such products in September as part of a broad initiative to reduce teen vaping. At the time, FDA Commissioner Scott Gottlieb said vaping had produced an “epidemic of nicotine addiction” among America’s youth, with a prevalence that was “simply not tolerable.”

The Monitoring the Future researchers agreed that stronger action was needed to keep vaping devices beyond the reach of minors. Regulators will need to pay close attention to the fast-changing market and be ready to modify their policies if necessary, they said.

Miech applauded the FDA’s recent focus on kid-friendly flavors of vaping liquids. He also praised the agency for paying particular attention to Juul; the company’s devices have become so popular among middle- and high-school students that “juuling” is now synonymous with vaping.

The sharp increase in teen vaping was revealed in surveys completed by a nationally representative group of 13,850 students. The eighth-, 10th- and 12th-graders completed their questionnaires at school during a normal class period.


The 2014 edition of the Monitoring the Future study was the first to report that vaping had replaced smoking as the most popular way for teens to consume tobacco. Even as other forms of tobacco use declined among students, e-cigarettes continuously bucked that trend.

Still, the increase in the past year was striking.

Among 12th-graders, the proportion of students who said they had vaped a nicotine product in the 30 days before they took the survey soared from 11 percent in 2017 to 20.9 percent in 2018. Among 10th-graders, it jumped from 8.2 percent in 2017 to 16.1 percent in 2018, and among eighth-graders it rose from 3.5 percent last year to 6.1 percent this year.

The survey also asked about vaping of liquids that contained “just flavoring,” to track students who may have consumed nicotine without realizing it. When both categories of vaping were combined, the researchers found that 25 percent of high-school seniors, 20.3 percent of sophomores and 9.7 percent of eighth-graders used e-cigarettes in 2018.

The use of any kind of nicotine-containing product including traditional cigarettes, cigars and smokeless tobacco by 12th-graders grew from 23.7 percent in 2017 to 28.9 percent in 2018.

“This increase was driven solely by nicotine vaping, given that the use of each of the other six nicotine products declined,” the researchers wrote in the New England Journal of Medicine.


In other words, the rise of vaping has reversed recent progress in turning kids away from nicotine, Miech said. Researchers have found that high-school students who vape are much more likely to become cigarette smokers than their classmates who don’t vape.

“These results suggest that vaping is leading youth into nicotine use and nicotine addiction, not away from it,” Miech said in a statement.

Students’ growing attraction to vaping extended to marijuana, which increased by at least 50 percent across the board. In 2018, 7.5 percent of seniors, 7 percent of sophomores and 2.6 percent of eighth-graders said they had vaped marijuana in the past 30 days.

Use of other illicit drugs including cocaine, methamphetamine, heroin, ecstasy and hallucinogens did not change substantially in the past year, according to the survey results.

Although overall alcohol use didn’t change, high-school seniors were less likely to engage in binge drinking in 2018. The proportion of students who said they downed five or more drinks in a row at least once in the previous two weeks fell to 14 percent, from nearly 17 percent in 2017.

Monitoring the Future is funded by the National Institute on Drug Abuse, which is part of the National Institutes of Health.

Karen Kaplan


2018-12-17

[Science News] Overactive immune system 'may trigger ME-like symptoms'


The immune system is a super complex army of more than two dozens different cells, organs and protein forces.

We explain how it keeps you alive and how different illnesses work.


Overactive immune system 'may trigger ME-like symptoms'
By Laurel Ives
BBC Health

An overactive immune system may help explain the cause of chronic fatigue syndrome, scientists from King's College London have suggested.

Many sufferers of CFS, or ME, say their condition began with a challenge to their immune system like an infection.

The scientists studied 55 patients with Hepatitis C who were given a drug that causes a similar response to a virus.

Eighteen of those patients had an overactive immune system and went on to develop CFS-like symptoms.

'It is a light in the fog'
Chronic fatigue syndrome is a long-term illness characterised by extreme tiredness.

Scientists from the Institute of Psychiatry, Psychology and Neuroscience at King's College recruited 55 patients who had hepatitis C. The standard treatment for hepatitis C is the drug interferon-alpha which challenges the immune system in the same way as a powerful infection.

The team measured fatigue and immune markers before, during and after treatment, tracking which people developed the persistent CFS-like illness.

In the 18 patients who developed CFS-like symptoms the team found a much stronger immune response to the medication. Significantly these patients also had an overactive immune system before the treatment started.

Lead researcher Dr Alice Russell from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) said:

"For the first time, we have shown that people who are prone to develop a CFS-like illness have an overactive immune system, both before and during a challenge to the immune system.

"Our findings suggest that people who have an exaggerated immune response to a trigger may be more at risk of developing CFS."

Senior researcher, Prof Carmine Pariante, added: "This is a light in the fog, a direction of travel. Although screening is a long way off, our results are the first step in identifying those at risk and catching the illness in its crucial early stages."

Article From: https://www.bbc.com/news/health-46570494



2018-12-13

Go back to the iMessage sticker because the WhatsApp sticker was still rejected in the App Store.


I had to go back to the iMessage sticker because the WhatsApp sticker was still rejected in the App Store.

I hope that WhatsApp and Apple will work together well, but it seems to have failed.
Revenue has dropped significantly because all My WhatsApp sticker sales that were registered have been stopped.



My wife made a decorative sticker in preparation for the upcoming Christmas.

Christmas Deco
https://itunes.apple.com/kr/app/christmas-deco/id1446446018?mt=8




I think i will have to make iMessage stickers mainly for the time being.

[Science News] Tips for meteor shower watcher.


Google doodle explains formation of Geminids meteor shower

TIMESOFINDIA.COM | Dec 13, 2018, 08.44 AM IST

NEW DELHI: Google has dedicated a doodle to a burst of Geminids meteor shower expected to dart across the sky tonight.

The doodle consists of a series of seven animated images explaining the phenomenon of Geminids meteor shower.

The Geminids meteor shower has been active all week but will peak tonight when 20 times more shooting stars than normal will be visible.

David Moore of Astronomy Ireland said: "Even city dwellers could see a shooting star every couple of minutes.

"Those in dark rural skies could see more than one every minute," he said.

The Geminids are meteor shower active every December, when Earth passes through a massive trail of dusty debris by 3200 Phaethon, "a weird, rocky object", according to NASA.

The meteor shower is a consequence of the dust and grit burning up as it enters the Earth's atmosphere.

Scientists are not sure of the very nature of Phaethon. Some believe it to be a near-Earth asteroid, while the others attribute it to an extinct comet, sometimes also called a rock comet.



Tips for meteor shower watcher

Find the darkest place in your area and give your eyes 30 minutes to adapt to the dark.

Avoid looking at your mobile phone as it is likely to tamper with your night vision.

Lie flat on your back and look straight up, taking as much sky as possible.


Soon, you shall be able to see the Geminids meteor shower.


With the passage of time, the meteor shower will increase, hitting a rate of about 100 per hour around 2 am.


Unfortunately, those in cities, including suburbs, are unlikely to witness this spectacular marvel due to pollution and excess of lights.


Dark and clear skies are necessary to observe the Geminids meteor shower.

2018-12-10

[Science News] Groundbreaking study examines effects of screen time on kids


[Science News] Groundbreaking study examines effects of screen time on kids
From: https://www.cbsnews.com/news/groundbreaking-study-examines-effects-of-screen-time-on-kids-60-minutes/

If you have kids and wonder if all that time they spend on their smartphones endlessly scrolling, snapping and texting is affecting their brains, you might want to put down your own phone and pay attention. The federal government, through the National Institutes of Health, has launched the most ambitious study of adolescent brain development ever attempted. In part, scientists are trying to understand what no one currently does: how all that screen time impacts the physical structure of your kids' brains, as well as their emotional development and mental health.

At 21 sites across the country scientists have begun interviewing nine and ten-year-olds and scanning their brains. They'll follow more than 11,000 kids for a decade, and spend $300 million doing it. Dr. Gaya Dowling of the National Institutes of Health gave us a glimpse of what they've learned so far.
Dr. Gaya Dowling: The focus when we first started talking about doing this study was tobacco, marijuana, all drugs the screen time component really came into play because we were wondering what is the impact? I mean, clearly kids spend so much time on screens.
The first wave of data from brain scans of 4,500 participants is in and it has Dr. Dowling of the NIH and other scientists intrigued.
The MRI's found significant differences in the brains of some kids who use smartphones, tablets, and video games more than seven hours a day.

"We're sort of in the midst of a natural kind of uncontrolled experiment on the next generation of children."

Dr. Gaya Dowling: What we can say is that this is what the brains look like of kids who spend a lot of time on screens. And it's not just one pattern.
Anderson Cooper: That's fascinating.
Dr. Gaya Dowling: It's very fascinating.
The colors show differences in the nine and ten-year-olds' brains. The red color represents premature thinning of the cortex. That's the wrinkly outermost layer of the brain that processes information from the five senses.
Anderson Cooper: What is a thinning of the cortex mean?
Dr. Gaya Dowling: That's typically thought to be a maturational process. So what we would expect to see later is happening a little bit earlier.
Anderson Cooper: Should parents be concerned by that?
Dr. Gaya Dowling: We don't know if it's being caused by the screen time. We don't know yet if it's a bad thing. It won't be until we follow them over time that we will see if there are outcomes that are associated with the differences that we're seeing in this single snapshot.
The interviews and data from the NIH study have already revealed something else: kids who spend more than two hours a day on screens got lower scores on thinking and language tests.
Anderson Cooper: When the study is complete, is it possible that a researcher will be able to say whether or not screen time is actually addictive?
Dr. Gaya Dowling: We hope so. We'll be able to see not only how much time are they spending, how they perceive it impacting them, but also what are some of the outcomes. And that will get at the question of whether there's addiction or not.
Anderson Cooper: When will you have the answers that you're searching for?
Dr. Gaya Dowling: Some questions we'll be able to answer in a few years. But some of the really interesting questions about these long-term outcomes, we're gonna have to wait awhile because they need to happen.
That delay leaves researchers who study technology's impact on very small children anxious.
Dr. Dimitri Christakis: In many ways, the concern that investigators like I have is that we're sort of in the midst of a natural kind of uncontrolled experiment on the next generation of children.
Dr. Dimitri Christakis at Seattle Children's Hospital was the lead author of the American Academy of Pediatrics' most recent guidelines for screen time. They now recommend parents, "avoid digital media use, except video chatting, in children younger than 18 to 24 months."

Get the Smartphone out of the kids.
The American Academy of Pediatrics (AAP) and the Canadian Society of Pediatrics should not be exposed to electronic appliances from 0 to 2 years old, The 18-year-old announced that exposure should be limited to two hours a day. (AAP 2001/13, CPS 2010)
The following ten studies support this claim. Information on the results of the studies mentioned is listed in the zone's Fact Sheet on the zonein.ca site.

1. For rapid brain development
2. Causes developmental delay
3. Rapidly increasing obesity
4. Sleep deprivation
5. Increase in mental illness rate
6. Increased aggression
7. Digital Dementia
8. Electronic device poisoning
9. Serious electromagnetic wave exposure
10. For a sustainable future

2018-12-07

[Science News] What gas was used in Schindler's List Gas Chamber scene.


[Science News] What gas was used in Schindler's List Gas Chamber scene.

Schindler's List is a 1993 American epic historical period drama film directed and co-produced by Steven Spielberg and written by Steven Zaillian. It is based on the novel Schindler's Ark by Australian novelist Thomas Keneally. The film follows Oskar Schindler, a Sudeten German businessman, who saved the lives of more than a thousand mostly Polish-Jewish refugees from the Holocaust by employing them in his factories during World War II. It stars Liam Neeson as Schindler, Ralph Fiennes as SS officer Amon Göth, and Ben Kingsley as Schindler's Jewish accountant Itzhak Stern.

Ideas for a film about the Schindlerjuden (Schindler Jews) were proposed as early as 1963. Poldek Pfefferberg, one of the Schindlerjuden, made it his life's mission to tell the story of Schindler. Spielberg became interested in the story when executive Sidney Sheinberg sent him a book review of Schindler's Ark. Universal Pictures bought the rights to the novel, but Spielberg, unsure if he was ready to make a film about the Holocaust, tried to pass the project to several other directors before finally deciding to direct the film himself.

Principal photography took place in Kraków, Poland, over the course of 72 days in 1993. Spielberg shot the film in black and white and approached it as a documentary. Cinematographer Janusz Kamiński wanted to give the film a sense of timelessness. John Williams composed the score, and violinist Itzhak Perlman performs the film's main theme.

Schindler's List premiered on November 30, 1993, in Washington, D.C. and it was released on December 15, 1993, in the United States. Often listed among the greatest films ever made, it was also a box office success, earning $321.2 million worldwide on a $22 million budget. It was the recipient of seven Academy Awards (out of twelve nominations), including Best Picture, Best Director, Best Adapted Screenplay, and Best Original Score, as well as numerous other awards (including seven BAFTAs and three Golden Globes). In 2007, the American Film Institute ranked the film 8th on its list of the 100 best American films of all time. The Library of Congress selected it for preservation in the National Film Registry in 2004.




-What is Zyklon B and Carbon monoxide

Zyklon B
From Wikipedia, the free encyclopedia
Zyklon B (German: [tsyˈkloːn ˈbeː] (About this soundlisten); translated Cyclone B) was the trade name of a cyanide-based pesticide invented in Germany in the early 1920s. It consisted of hydrogen cyanide (prussic acid), as well as a cautionary eye irritant and one of several adsorbents such as diatomaceous earth. The product is infamous for its use by Nazi Germany during the Holocaust to murder approximately one million people in gas chambers installed at Auschwitz-Birkenau, Majdanek, and other extermination camps.



Hydrogen cyanide, a poisonous gas that interferes with cellular respiration, was first used as a pesticide in California in the 1880s. Research at Degesch of Germany led to the development of Zyklon (later known as Zyklon A), a pesticide which released hydrogen cyanide upon exposure to water and heat. It was banned after a similar product was used by Germany as a chemical weapon in World War I. In 1922, Degesch was purchased by Degussa, where a team of chemists that included Walter Heerdt [de] and Bruno Tesch developed a method of packaging hydrogen cyanide in sealed canisters along with a cautionary eye irritant and one of several adsorbents such as diatomaceous earth. The new product was also named Zyklon, but it became known as Zyklon B to distinguish it from the earlier version. Uses included delousing clothing and disinfesting ships, warehouses, and trains.

In early 1942, Zyklon B emerged as the preferred killing tool of Nazi Germany for use in extermination camps during the Holocaust. Around a million people were killed using this method, mostly at Auschwitz. Tesch was executed in 1946 for knowingly selling the product to the SS for use on humans. Hydrogen cyanide is now rarely used as a pesticide, but still has industrial applications. Firms in several countries continue to produce Zyklon B under alternative brand names, including Detia-Degesch, the successor to Degesch, who renamed the product Cyanosil in 1974.



Carbon monoxide
From Wikipedia, the free encyclopedia

Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is slightly less dense than air. It is toxic to animals that use hemoglobin as an oxygen carrier (both invertebrate and vertebrate, including humans) when encountered in concentrations above about 35 ppm, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal biological functions. In the atmosphere, it is spatially variable and short lived, having a role in the formation of ground-level ozone.



Carbon monoxide consists of one carbon atom and one oxygen atom, connected by a triple bond that consists of two covalent bonds as well as one dative covalent bond. It is the simplest oxocarbon and is isoelectronic with other triply-bonded diatomic molecules having ten valence electrons, including the cyanide anion, the nitrosonium cation and molecular nitrogen. In coordination complexes the carbon monoxide ligand is called carbonyl.

Toxicity
Main article: Carbon monoxide poisoning
Carbon monoxide poisoning is the most common type of fatal air poisoning in many countries. Carbon monoxide is colorless, odorless, and tasteless, but highly toxic. It combines with hemoglobin to produce carboxyhemoglobin, which usurps the space in hemoglobin that normally carries oxygen, but is ineffective for delivering oxygen to bodily tissues. Concentrations as low as 667 ppm may cause up to 50% of the body's hemoglobin to convert to carboxyhemoglobin. A level of 50% carboxyhemoglobin may result in seizure, coma, and fatality. In the United States, the OSHA limits long-term workplace exposure levels above 50 ppm.

The most common symptoms of carbon monoxide poisoning may resemble other types of poisonings and infections, including symptoms such as headache, nausea, vomiting, dizziness, fatigue, and a feeling of weakness. Affected families often believe they are victims of food poisoning. Infants may be irritable and feed poorly. Neurological signs include confusion, disorientation, visual disturbance, syncope (fainting), and seizures.

Some descriptions of carbon monoxide poisoning include retinal hemorrhages, and an abnormal cherry-red blood hue. In most clinical diagnoses these signs are seldom noticed. One difficulty with the usefulness of this cherry-red effect is that it corrects, or masks, what would otherwise be an unhealthy appearance, since the chief effect of removing deoxygenated hemoglobin is to make an asphyxiated person appear more normal, or a dead person appear more lifelike, similar to the effect of red colorants in embalming fluid. The "false" or unphysiologic red-coloring effect in anoxic CO-poisoned tissue is related to the meat-coloring commercial use of carbon monoxide, discussed below.

Carbon monoxide also binds to other molecules such as myoglobin and mitochondrial cytochrome oxidase. Exposures to carbon monoxide may cause significant damage to the heart and central nervous system, especially to the globus pallidus, often with long-term chronic pathological conditions. Carbon monoxide may have severe adverse effects on the fetus of a pregnant woman.

2018-12-06

[Science News] Disneyland cooling tower was likely source of all 22 Legionnaires' cases, official testifies-What is Legionnaires' disease?


[Science News] Disneyland cooling tower was likely source of all 22 Legionnaires' cases, official testifies-What is Legionnaires' disease?



A cooling tower at Disneyland was the likely source for all 22 cases in a Legionnaires’ disease outbreak last year near the theme park, an Orange County health official testified Tuesday.
Most of those who fell ill visited the park in the fall of 2017. Disneyland has denied it was the source, pointing to three infected people who had been in Anaheim but not at Disneyland. One of them died.
Dr. Matthew Zahn, medical director for epidemiology at the Orange County Health Care Agency, told an appeals board judge at the California Occupational Safety and Health Administration that those three people were in nursing homes in Anaheim. He said health workers visited the nursing homes and determined there were no likely sources of the Legionella bacteria there.
Tests around the time of the outbreak showed high levels of Legionella bacteria in two of Disneyland’s cooling towers, which likely spread contaminated droplets to people in the park, Zahn said. The medical director said he concluded the three nursing home patients were probably sickened by Disneyland as well, because water infected with Legionella bacteria “can spread two to four miles.”

Zahn pointed out that cooling towers — part of an air-conditioning system that releases mist — are the most common source of Legionnaires’ outbreaks.
Disneyland cooling tower #4 had very high levels of Legionella bacteria when people began to fall sick, Zahn said. Once it was sanitized, Legionnaires’ infections appeared to cease, he added.
“Most likely those cases were related to a common exposure,” Zahn said. “Cooling tower #4 was the most likely source of exposure.”
The health agency has never formally identified a cause of the outbreak. Upon questioning by Disneyland’s lawyers, Zahn said he could not be 100% certain that Disneyland was the source of all of the cases without additional testing.
He also said the county’s environmental health workers could not identify a source of the outbreak when they examined the park’s water sources in October last year.
“They did not find an obvious — on their pass through — source,” Zahn said.


Legionnaires' disease

From Wikipedia, the free encyclopedia
Jump to navigationJump to search
Legionnaires' disease
SynonymsLegionellosis,[1] legion fever
Legionella pneumophila 01.jpg
Transmission electron microscopy image of L. pneumophila, responsible for over 90% of Legionnaires' disease cases[2]
SpecialtyInfectious diseasepulmonology
SymptomsCough, shortness of breathfevermuscle pains, headaches[3]
Usual onset2–10 days after exposure[3]
CausesBacteria of the Legionella type (spread by contaminated mist)[4][5]
Risk factorsOlder age, history of smoking, chronic lung diseasepoor immune function[6]
Diagnostic methodUrinary antigen testsputum culture[7]
PreventionGood maintenance of water systems[8]
TreatmentAntibiotics[9]
Prognosis10% risk of death[9]
Frequency~13,000 severe cases a year (US)[10]
Legionnaires' disease, also known as legionellosis, is a form of atypical pneumonia caused by any type of Legionella bacteria.[4]Signs and symptoms include cough, shortness of breath, high fevermuscle pains, and headaches.[3] Nausea, vomiting, and diarrhea may also occur.[1] This often begins 2-10 days after exposure.[3]
The bacterium is found naturally in fresh water.[5] It can contaminate hot water tanks, hot tubs, and cooling towers of large air conditioners.[5] It is usually spread by breathing in mist that contains the bacteria.[5] It can also occur when contaminated water is aspirated.[5] It typically does not spread directly between people, and most people who are exposed do not become infected.[5]Risk factors for infection include older age, a history of smoking, chronic lung disease, and poor immune function.[6] Those with severe pneumonia and those with pneumonia and a recent travel history should be tested for the disease.[11] Diagnosis is by a urinary antigen test and sputum culture.[7]
No vaccine is available.[8] Prevention depends on good maintenance of water systems.[8] Treatment of Legionnaires' disease is with antibiotics.[9] Recommended agents include fluoroquinolonesazithromycin, or doxycycline.[12] Hospitalization is often required.[11] About 10% of those who are infected die.[9]
The number of cases that occur globally is not known.[1] Legionnaires' disease is the cause of an estimated 2-9% of pneumonia cases that are acquired outside of hospital.[1] An estimated 8,000 to 18,000 cases a year in the United States require hospitalization.[10] Outbreaks of disease account for a minority of cases.[1][13] While it can occur any time of the year, it is more common in the summer and fall.[10] The disease is named after the outbreak where it was first identified, at a 1976 American Legion convention in Philadelphia.[14]