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last updated: Thu, 24 Jul 2014 19:03:01 GMT

 Thu, 24 Jul 2014 11:45:00 GMT Deadly MERS 'camel flu' may now be airborne

“Deadly Mers virus 'could now be airborne',” The Independent reports. The Middle East Respiratory Syndrome (MERS) virus, which has an estimated case fatality rate of 30%, has been detected in an air sample in a camel barn in Saudi Arabia. This raises the possibility the virus could be spread through the air in the same way as flu.

MERS emerged in 2012 and can be extremely serious, leading to severe breathing difficulties, kidney failure and death (though it appears some people may become unaffected carriers of the virus).

The World Health Organization (WHO) states that 837 laboratory-confirmed cases of infection have been reported since 2012, including at least 291 related deaths.

In 2013, evidence emerged that camels could be the main source of the virus (hence the nickname). 

The research behind the story highlights the case of a man and his camels living in Saudi Arabia. The man and some of his camels were infected with MERS, and the man sadly died as a result. 

On investigation, genetic fragments from the MERS virus were detected in an air sample from the barn housing the infected camels.

There is no concrete evidence that the man was infected through the air, and it should also be noted that he had direct contact with the camels. However, the possibility of airborne transmission has raised concerns. 

It is important to keep researching this new virus and tracking its spread, to gain a better understanding of how it is transmitted to people.

 

Where did the story come from?

The study was carried out by researchers from King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia, and was funded by the same institution.

The study was published in the American Society for Microbiology, a peer-reviewed science journal.

This whole journal is open-access, meaning that anyone can read the publications for free online, including this latest research.

The study highlights new research into the origins and possible transmission of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) – a new human virus that causes severe respiratory symptoms and kidney failure.

Since it was recognised, the WHO reports there have been 837 laboratory confirmed cases in humans, and at least 291 deaths.

The authors report that these have been in at least 17 countries in Asia, Africa, Europe and North America – most originated from countries in the Arabian Peninsula, including Saudi Arabia.

They say the virus has the ability to infect close contacts such as family members and healthcare workers, and that it causes the death of many of those affected. This means the virus is a potential global public health threat. A case death rate of just under 30% is unusually high for a respiratory virus, a statistic that has sparked concern.

The authors say the origin and transmission of MERS is not fully understood, but it seems humans could contract it through direct contact with infected camels. However, intermediate steps in this process have been suggested, as well as airborne transmission.

This latest research aimed to investigate whether MERS-CoV might be transmitted from camels to humans via the air.

 

What kind of research was this?

This was a laboratory analysis of air samples collected from a camel barn in Saudi Arabia.

The researchers knew of a man and some of his nine camels that had contracted exactly the same MERS virus (100% identical when tested in the lab), suggesting that the camels had infected the man. 

However, it was not clear whether the man contracted the virus from touching the camels or from breathing in air containing the virus originating from the camels.

 

What did the research involve?

The researchers tested the air from the barn where the infected camels were housed for traces of the MERS virus to see if, at least in theory, it was possible for the virus to be transmitted through the air.

The man became unwell on October 26 2013 and reported that four of his camels had suffered respiratory illness since October 19. He was admitted to an intensive care unit (ICU) on November 3 2013. Three air samples were collected from the camel barn on three consecutive days from November 7. All three samples were screened for the presence of the MERS virus genetic material, and the camels were tested for the MERS-CoV infection.

The man died on November 18 2013; his camels appear to have survived.

 

What were the basic results?

Only the first air sample tested positive for airborne MERS genetic material. The other two samples, collected in the next two days, were negative. The authors note that the first sample was collected on the same day as one of the nine camels also tested positive for the MERS infection, although four of the nine camels had been showing signs of respiratory illness for many weeks.

They confirmed that the genetic fragments from the air were 100% identical to fragments found in the infected man and the infected camel. This, they said, suggested that the genetic material in the air had originated from the infected camel.

The virus material from the air samples was not able to infect cells in the laboratory, indicating there may have been loss of viral infectivity from the air sample.

 

How did the researchers interpret the results?

The authors say the data suggests that, “camels may be a source of infectious MERS-CoV, which can be transmitted to humans within confined spaces” and that, “these results also suggest that air sampling might be a useful approach to investigate the role of the airborne transmission of MERS-CoV spread and shedding.”

They added that, “further studies are urgently needed to fully understand the role of camels in the transmission of MERS-CoV and whether airborne transmission plays a role in MERS-CoV spread, in order to implement control and prevention measures to prevent the transmission of this deadly virus.”

 

Conclusion

This genetic research found genetic fragments from the MERS virus in an air sample of a barn housing MERS-infected camels. This raises the possibility that the owner contracted the MERS virus from airborne transmission, rather than through direct contact, as had previously been assumed.

However, it is important to realise that, based on this research alone, there is no concrete evidence to suggest the transmission was airborne, only that it is a possibility to investigate further.

It was also unusual that the virus was only detected in one of the three air samples, taken 12 days after the onset of illness and four days after the man had been admitted to an ICU. There could be many explanations for this – such as ventilation in the barn. 

Either way, it highlights that more investigation is needed to establish whether the MERS virus, or at least some strains of it, is regularly airborne and how long it may stay airborne.

Research needs to establish how MERS infection is spread between camels and humans, and whether this can happen through the air. If it can, this makes the virus more likely to spread quicker and more widely, like other airborne diseases, such as flu. Research also needs to establish whether the MERS virus can remain infectious when on surfaces, which may be touched by people, providing further indirect infection routes.

This study is important because the MERS virus is new, so is not yet fully understood. It will be important to keep researching this virus and tracking its spread to better understand how it is transmitted to humans. This will, ultimately, help inform better prevention or control measures, thereby protecting people from this potentially fatal infection.

In the meantime, the WHO recommends strict control measures such as gloves, mask and eye protection for healthcare workers when caring for affected individuals. There are as yet no travel or trade restrictions, and no screening recommendations for entry into other countries.

Read the latest WHO Disease outbreak news here.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Deadly Mers virus 'could now be airborne', warn scientists in study on Saudi Arabian barn. The Independent, July 22 2014

Deadly MERS virus 'may be airborne', sparking fears it may spread quicker. Mail Online, July 23 2014

Links To Science

Azhar EI, Hashem AM, El-Kafraw SA, et al. Detection of the Middle East Respiratory Syndrome Coronavirus Genome in an Air Sample Originating from a Camel Barn Owned by an Infected Patient. mBio. Published online July 22 2014

 Thu, 24 Jul 2014 11:30:00 GMT Paracetamol 'doesn't work' for lower back pain

“Paracetamol used to treat acute lower back pain is no better than a dummy pill,” BBC News reports. A well-conducted trial casts doubts on the widespread recommendation that paracetamol is an effective treatment for lower back pain.

It reports on a randomised double-blind controlled trial of people with acute low back pain. All participants were told to remain active and avoid bed rest. They were split into three groups and asked to take regular medication and “as required” medication, if needed. This was either paracetamol or a placebo.

The average number of days to recovery for each group was between 16 and 17 days. Sustained recovery by 12 weeks was achieved by between 83% and 85% in all groups.

The severity of acute low back pain in this group was not sufficient to cause anyone to have time off work. This means the results of this study may not be applicable to people with more severe acute low back pain.

This was a well conducted study that would appear to suggest that the advice regarding paracetamol as a first-line treatment may need re-examining. However, as the authors themselves argue, it is too soon to start rewriting clinical guidelines for lower back pain based on this evidence alone.

 

Where did the story come from?

The study was carried out by researchers from the University of Sydney, University of New South Wales and University of Newcastle, all in Australia. It was funded by the National Health and Medical Research Council of Australia and GlaxoSmithKline Australia. 

The study was published in the peer-reviewed medical journal The Lancet.

It was widely covered in the UK media, and most of the coverage was fair and of a good quality, with several sources reporting comments from independent experts.

 

What kind of research was this?

This was a double-blind randomised controlled trial (RCT) looking at the effectiveness of paracetamol in improving recovery time from acute low back pain, compared to placebo.

An RCT is the best type of study design to find out whether healthcare treatments are effective.

The authors say that low back pain is a leading cause of disability worldwide and that guidelines on the topic universally recommend paracetamol as a first-line treatment.

This is despite the surprising fact that there is no high-quality evidence to support this recommendation.

The only other RCT the authors could find on the use of paracetamol compared with no active treatment in treating low back pain involved just 46 people.

 

What did the research involve?

The researchers recruited people with acute low back pain from 235 primary care centres across Australia. Patients had to be suffering a new episode of acute lower back pain (defined as shorter than six weeks duration and preceded by one month of no pain), with or without leg pain. The pain had to be of at least moderate intensity as measured by a validated scale.

People suspected of having serious spinal diseases such as cancer or fracture, or who were already regularly using painkillers, or who had had spinal surgery in the previous six months were excluded from the trial.

The trial had a “double dummy” design, which is a method of keeping participants and researchers “blind” to the treatment allocated, when two treatments cannot be made identical; in this case, there is a clear difference between taking paracetamol regularly and taking it as needed.

Participants were asked to take two tablets three times per day from a sealed “regular” box of pre-prepared medication, and had access to a sealed “as required” box for additional pain relief.

From this box, they could take one or two tablets up to four times per day. They were randomised by computer to one of three treatment groups:

  • a “regular” box of paracetamol – (the equivalent of 3,990 mg daily) and a placebo “as required” box
  • a “regular” placebo box and “as required” paracetamol box  (maximum of 4,000 mg daily)
  • placebo pills in both boxes

Neither patients, researchers, doctors nor other staff knew to which group patients were allocated.

All patients received advice about keeping active, avoiding bed rest and reassurance about their back pain and were followed up at one, two, four and 12 weeks. They were asked to continue the medicine until they recovered, or for four weeks, whichever occurred first. “Rescue” medication – two day's supply of a painkiller called naproxen – was available for those with continuing severe pain assessed after one week.

Participants recorded pain scores into a daily pain and drug diary until they recovered or for four weeks, whichever was sooner. This was transcribed into a case report either by telephone interview or directly into an online database.

Researchers looked at the time until the participants recovered from pain, measured in days. Recovery was defined as the first day of 0 or 1 pain intensity as measured on a 0-10 pain scale, for seven consecutive days.

Using various validated scales, they also looked at

  • pain intensity
  • disability (assessed using a validated scale from 0 to 24)
  • function
  • global rating of symptom change
  • sleep quality 
  • quality of life
  • feelings of depression

They also monitored participants’ adherence to treatment, satisfaction with treatment, use of other drugs and absence from work.

They analysed the results using standard statistical methods.

 

What were the basic results?

There were 1,652 people in the trial and the mean level of pain intensity at the start of the trial was 6.3 out of 10.

The researchers found that there was no significant difference in the number of days to recovery between the three groups.

The average time to recovery from back pain was

  • 17 days (95% Confidence interval [CI] 14 to 19) in people taking paracetamol regularly
  • 17 days (95% CI 15 to 20) in those taking paracetamol as needed
  • 16 days (95% CI 14 to 20) in the placebo group

By 12 weeks, sustained recovery had occurred in 85% of participants in the regular group, 83% in the as required group and 84% in the placebo group.

Adherence to the regular tablets was initially high in all three groups, with median tablets consumed 5.4 out of the maximum of 6. This reduced in all three groups over the first four weeks to 1.6 in the regular group, 0.6 in the as required group and 1.2 in the placebo group. As required medication was only taken by any participant during the first week, with a mean average of 1.9 tablets per day in each group.

Rescue use of the non-steroidal medication, naproxen was only taken by up to 1% of participants during the first two weeks.

The number of participants reporting adverse events was similar between the groups (18.5% in the regular group, 18.7% in the as-needed group and 18.5% in the placebo group)

None of the participants were absent from work during the study period.

Between 72% and 76% of participants were satisfied with the treatment received, and around 30% of participants used other health services, such as physiotherapy.

Paracetamol had no statistically significant effect on short-term pain levels, disability, function, sleep quality or quality of life.

 

How did the researchers interpret the results?

The researchers say their findings suggest that paracetamol taken regularly or as needed does not affect recovery time compared with placebo in patients with acute low back pain.

“Simple analgesics such as paracetamol might not be of primary importance in the management of acute lower back pain”, said lead author Dr Christopher Williams from the University of Sydney in Australia, in an accompanying press release. “The results suggest we need to reconsider the universal recommendation to provide paracetamol as a first-line treatment for low-back pain, although understanding why paracetamol works for other pain states but not low-back pain would help direct future treatments.”

The researchers also say that recovery time in the trial was faster on average than in similar trials and say this could be because the advice and reassurance provided is more effective than drugs for acute low back pain.

 

Conclusion

This was a well-designed double-blind RCT to assess the effectiveness of paracetamol for acute low back pain.

Attempts were made to account for any confounding factors and there was good follow-up, with analysis provided for 97% of participants.

However, as the authors point out, this study had some limitations – for example, those taking part did not typically take the full recommended dose of paracetamol; and also, some used other treatments during the study period. It is also interesting to note that the severity of acute low back pain people were experiencing was not sufficient to cause anyone to have time off work. And very few required additional “as required” medication and only up to 1% took any of the non-steroidal anti-inflammatory medication, naproxen.

This suggests the results of this study might not be applicable to people with more severe acute low back pain, who may not respond to a placebo treatment in the same way.

Overall, however, this was a well-designed trial and the results are likely to be reliable. Why paracetamol may help with other types of moderate or severe pain – such as tooth extraction – but possibly not with low back pain, is uncertain.

As the authors say, further research is required on the effectiveness of paracetamol for low back pain before any changes are considered to existing guidelines.

Back pain is common and can be distressing, but in most cases it is not serious and usually gets better within 12 weeks. Encouragingly, sustained recovery was achieved by between 83% and 85% of the study participants which supports current advice to keep active and carry on with daily activities if you have acute back pain. Other treatments include hot and cold compression packs, manual therapy and exercise.

Paracetamol is safe when taken at the correct dose, but you should always check whether other medicines you are taking contain paracetamol. This way you can make sure that you do not accidentally exceed the maximum daily dose.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Paracetamol for low back pain 'no better than placebo'. BBC News, July 24 2014

Paracetamol does not help lower back pain, study finds. The Guardian, July 24 2014

Paracetamol 'fails to ease low back pain’. The Daily Telegraph, July 24 2014

Paracetamol 'has no effect on back pain': Research casts doubt on most popular GP remedy. Daily Mail, July 24 2014

Paracetamol 'no better than a placebo' for lower back pain scientists claim. Daily Mirror, July 24 2014

Paracetamol cannot help back pain, say scientists. The Times, July 24 2014

Paracetamol is useless for easing back pain, say experts. Daily Express, July 24 2014

Links To Science

Williams CM, Maher CG, Latimer J, et al. Efficacy of paracetamol for acute low-back pain: a double-blind, randomised controlled trial. The Lancet. Published online July 24 2014

 Wed, 23 Jul 2014 15:19:00 GMT Sleep deprivation may affect memory

The Mail Online states that “just one bad night’s sleep can have a dramatic effect on your memory – even leading to false memories”.

Though the results of this small experimental study involving US students are interesting, they're far from dramatic.

Researchers were interested in investigating whether sleep deprivation has an effect on a person’s susceptibility to false memories, which are surprisingly common.

In one famous study, many people claimed to have seen Bugs Bunny when visiting Disneyland as a child. This is plainly untrue, as Bugs Bunny is a Warner Brothers character.

In the first part of the experiment, people who self-reported having less than five hours sleep the night before the test were more likely to report seeing non-existent footage of the 9/11 plane crash in Pennsylvania.

People were then shown photos of two staged thefts, then given false written descriptions of it and questioned about what they had seen in the photos. In this test, there was no difference between people self-reporting sleep deprivation or not on recall.

In the second experiment, they took a separate group of students and then either let them sleep for a night or kept them awake, then saw how they performed on the same “misinformation” task. In this test, there was a mixed pattern of results, which does not give a clear picture of how, or if, sleep deprivation may be associated with false memories.

 

Where did the story come from?

The study was carried out by researchers from the University of California and Michigan State University, in the US. No sources of financial support are reported, and the authors declare no conflicts of interest.

The study was published in the peer-reviewed scientific journal Psychological Science.

The Mail Online and The Daily Telegraph’s reporting on the study overstates its findings. The Mail makes claims of a “dramatic effect on your memory”, while the Telegraph argues that the false memories related to sleep deprivation could cause relationship problems.

Neither news site noted the limitations of this experimental scenario and the fact that only a few of the results were statistically significant. This makes the relationship far from convincing.

 

What kind of research was this?

This was an experimental study designed to investigate whether sleep deprivation has an effect on a person’s susceptibility to false memories.

The researchers say that memories are not “recorded” in the brain, but are reconstructed from multiple sources, meaning they can be changed following exposure to altered information after the event or other suggestive influences.

People can sometimes have completely false memories, recalling clear and vivid experiences that never happened – imagined events are sometimes confused with actual memories.

The researchers say that many studies have explored what factors could be behind false memories, but sleep deprivation has not yet been explored. This is what they aimed to investigate.

The study was conducted in two parts. The first experiment tested whether self-reported sleep deprivation the night before was associated with false memories of a news event and false memories in a task giving misleading information (a “misinformation task”).

In the second experiment, people were deprived of sleep to see what effect this had on their performance in the misinformation task.

 

What did the research involve?

Experiment 1

A total of 193 university students were recruited (average age 20, 76% women). They were asked to keep a sleep diary every morning for a week, detailing the time they went to bed, how long it took them to fall asleep, when they woke, when they got out of bed and how many times they woke up during the night.

They then took part in the first experiment, where they completed a questionnaire on the plane crash in Shanksville, Pennsylvania, during the September 11 2001 tragedy.

This crash was never captured on video, but the participants were asked to answer “yes” or “no” to the question of whether they had seen “video footage of the plane crashing, taken by one of the witnesses on the ground”. Following this questionnaire, they were then interviewed about it, where the interviewers again repeatedly suggested that footage of this crash was widely available.

In the misinformation task, they were shown two sets of 50 photographs – one set showing a man breaking into a parked car, and the other showing a woman encountering a thief who steals her wallet. Around 40 minutes later they then read two textural descriptions of each photo set. Each description contained three false statements of the event shown, embedded within the correct information. A further 20 minutes later they were then asked multiple choice questions relating to what they had seen in the photos.  

Experiment 2

In the second experiment, they experimentally manipulated the amount of sleep in a separate group of 104 university students (average 19 years, 54% women) who took part in the misinformation test. All were reported to regularly sleep at least six hours a night. 

The study used a two-by-two design so that the influence of two different things could be examined – sleep deprivation or normal sleep – and the timing that certain parts of the test were completed, morning or evening.

In the evening, all participants completed validated mood and sleep questionnaires. 

Participants were then split into two.

One group was assigned to sleep deprivation or normal sleep and then completed all parts of the misinformation task at 9am.

This means that those participants assigned to the sleep deprivation arm of this experiment would perform all parts of the task while sleep deprived.

The other group was assigned to sleep deprivation or normal sleep and then shown the two series of photographs in the evening before sleep (or not). This means that the photos were seen by all participants when they were not sleep deprived. Then at 9am they completed the remaining two parts of the misinformation task – being shown the misleading text descriptions about the photos and then completing the multiple choice questions.

Those who were assigned to sleep were allowed to sleep for eight hours, from midnight to 8am. Those assigned to stay awake were not allowed to sleep and were kept awake by watching films, playing games, using computers, eating snacks and again completing the sleep and mood questionnaires every two hours.

 

What were the basic results?

Experiment 1

Participants reported an average of 6.8 hours of sleep, and 28 participants (15%) reported five hours or less of sleep the night before the study. They coded these 28 participants as having restricted sleep, and compared their results with the remaining 165 participants (85%).

When completing questionnaires about the plane crash, the restricted sleep group was more likely to answer "yes" when asked if they had seen footage of the plane crash.

However, in the follow-up interviews, they were no more likely than the normal sleep group to falsely say they had seen the crash.

On the misinformation task, there was no significant difference between the restricted sleep and normal sleep groups.

Experiment 2

The researchers found no main effect of the timing of the misinformation task alone, when comparing all people who completed all three parts of the task (photos, text descriptions and questions) in the morning, with those who had been shown the photos the night before instead. The researchers found they had no difference in their recall.

Similarly, there was no main effect of sleep deprivation alone. There was a trend for memory scores to be lower in the sleep deprived group compared to the sleep group, but the differences fell short of statistical significance.

There was some interaction between sleep and time of test, however. When people did all parts of the test in the morning, those who were sleep deprived were more likely to have falsely reported on the multiple choices questions something that didn’t happen in the photos.

However, when people were shown the photos the night before sleep/no sleep, there was no difference in false memories between the sleep deprived and sleep groups.

As expected, when given the mood and sleep questions in the morning, people who were sleep deprived were more sleepy and had poorer mood than those who had slept.

 

How did the researchers interpret the results?

On the first experiment, the researchers say the findings “tentatively suggest” that restricted sleep is related to memory suggestibility. On the second, they say that the sleep-deprived group was more likely to have false memories compared to the rested group, but only when participants were sleep deprived for all three stages of the misinformation task (i.e. all parts completed in the morning).

 

Conclusion

This experimental study is thought to be one of the first that has investigated how sleep deprivation may be associated with false memories.

In the first part of the experiment, self-reported restricted sleep the night before the test was associated with false questionnaire reports of seeing footage of the 9/11 plane crash in Pennsylvania (which doesn’t exist). However, people with restricted sleep weren’t more likely to give false reports when subsequently directly interviewed about it.

In these people, self-reported restricted sleep was not associated with poorer performance on the misinformation task.

In the second experiment, where they took a separate group of people and manipulated their sleep, there was some evidence that people who were not allowed to sleep were more likely to have false recall of the photos, but only if all parts of the test were performed in the morning (i.e. when people were sleep deprived). If they were shown the photos the night before instead (when not sleep deprived), on completing the task in the morning, there was no difference between sleep deprived and sleep groups.

Therefore, overall, the mixed pattern of significant and non-significant results does not give a very clear picture. There are also further important limitations, including:

  • The small, specific groups tested – there were only two separate groups of 193 and 104 young, US university students. Other groups could give very different results.
  • In the first test, the definition of sleep deprivation was self-reporting five hours or less of sleep the night before the test. This is likely to include many inaccuracies, including that people may not be able to give a very reliable indication of their sleep quality and quantity in the sleep diary questions used. Previous research has found that people often under-estimate the amount of sleep they get.
  • There were also only 28 people in this “sleep deprived” group, making them a small group to compare against.
  • Similarly, preventing a group of people from sleeping at all during one night does not give a very reliable proxy for sleep deprivation in the real life situation, e.g. a pattern of poor sleep quality and quantity persisting over a much longer time period.
  • The tests used – asking people whether they have seen footage of the 9/11 plane crash in Pennsylvania, and giving them a test where they are shown photos of two incidents, then given incorrect descriptions of them – is also only a very restricted experimental test. They cannot reliably test how sleep deprivation may be associated with the recall of the wealth of our daily and lifetime experiences.
  • Also, if there is an association between sleep deprivation and false memories, the study is not able to take into account the various confounding factors (e.g. psychological, health-related and lifestyle) that may be associated with this.

Overall, any association between false memories and sleep is likely to be complex and influenced by many factors. This single experimental study does not provide very clear evidence of a definite link.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Lack of sleep implants 'false' memories in brain. The Daily Telegraph, July 22 2014

Feeling forgetful? Just ONE bad night's sleep can have a dramatic effect on your memory - and even lead to false memories, researchers warn. Mail Online, July 22 2014

Links To Science

Frenda SK, Patihis L, Loftus E, et al. Sleep Deprivation and False Memories. Psychological Medicine. Published online July 16 2014


 

 
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