WHO update on Zika Virus – Focus on neurological disorders

whoCheck out the latest on Zika virus from the World Health Organization – including new information on the potential association of Zika with neurological disorders. WHO has called for intensified research into these associations. See the link for the full report.

The second meeting of the Emergency Committee (EC) convened by the Director-General under the International Health Regulations (2005) (IHR 2005) regarding clusters of microcephaly cases and other neurological disorders in some areas affected by Zika virus was held by teleconference on 8 March 2016, from 13:00 to 16:45 Central European Time.

The WHO Secretariat briefed the Committee on action in implementing the Temporary Recommendations issued by the Director-General on 1 February 2016, and on clusters of microcephaly and Guillain-Barré Syndrome (GBS) that have had a temporal association with Zika virus transmission. The Committee was provided with additional data from observational, comparative and experimental studies on the possible causal association between Zika virus infection, microcephaly and GBS.

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10 things to know about Zika virus

The threat of Zika: Q&A

WHO says Zika virus is strongly suspected of causing birth defects and may infect 3-4 million people in the Americas.

Tarek Bazley | 31 Jan 2016 14:15 GMT

The Zika virus (yellow) is strongly suspected of causing birth defects. [Science Photo Library]

What is Zika virus?

Zika virus is a mosquito-transmitted infection related to dengue, yellow fever and West Nile virus.

Symptoms are mild and include fever, rash, joint pain and conjunctivitis (red eyes).

Just one in five people infected becomes ill. Hospitalisation is uncommon and deaths are rare.

How does it spread?

Zika is primarily spread through the bite of an infected Aedes species of mosquito.

Pregnant women can also pass the virus to their babies during pregnancy but how and when this happens is unclear.

Those infected can pass the virus on through a mosquito bite for about seven days after infection.

There are no reports of transmission through breastfeeding, but in a few cases the virus has been reported to have been passed on through blood transfusion and sexual contact.

Where is Zika?

The latest outbreak is in 23 countries in the Carribean, Central America, South America, Mexico and Puerto Rico.

Past outbreaks have been in Gabon, Egypt, Nigeria, Senegal, Sierra Leone, Côte d’Ivoire, the Central African Republic, Cambodia, Micronesia, Malaysia, Pakistan, India, Thailand, Philippines, and Indonesia.

How did Zika get to Brazil?

Nothing has been proven but Zika may have been brought to Brazil by participants of the Va’a World Sprint Canoeing World Championships, held in August 2014.

Athletes came from French Polynesia, New Caledonia, the Cook Islands and Easter Island.

It has also been suggested that Zika was brought by Asian tourists attending the 2014 FIFA World Cup, raising concerns that the Olympics, starting in Rio de Janeiro on August 5, will result in further spread of the virus.

How is Zika diagnosed?

A blood or tissue sample from the first week in the infection must be sent to an advanced laboratory.

The virus can be detected through sophisticated molecular testing that seeks out the active virus, which lasts in the body for about a week.

Research is being done to develop a rapid test which could look for antibodies after a patient has recovered from the virus, making it possible to test for immunity.

How is Zika treated?

There is no vaccine or specific medicine currently available and treatment is normally focused on relieving the symptoms.

Can a vaccine be developed?

In theory a vaccine is possible but development testing and trials for human vaccines normally take years and cost hundreds of millions of dollars.

A number of companies, including Inovio, Hawaii Biotech, GSK and Sanofi are developing or considering working on a vaccine.

Last year Sanofi received approval for the world’s first dengue vaccine.

Dengue is closely related to Zika but Sanofi is cautious about whether it could be adapted.

“There are too many unknowns about Zika to reliably judge the ability to research and develop a vaccine effectively at this time,” it said in a statement.

What is microcephaly and how is it linked?

Microcephaly is a birth defect characterised by incomplete brain development and an unusually small head.

It is a life-long condition with no cure or standard of treatment, and is linked with conditions such as seizures, developmental delays and intellectual problems.

Microcephaly is normally uncommon. In the US, there are typically between two and 12 cases per 10,000 newborns.

The condition is being reported in the worst Zika-affected areas in Brazil at dramatically higher rates: 100 cases for every 10,000, or 1 percent of births.

Research from Brazil has suggested there is a correlation between the location and timing of this Zika outbreak and the increase in cases of microcephaly, but there is currently no proof that the virus causes the birth defect.

However, Zika virus has been found in the amniotic fluid of pregnant women with the virus and in the placentas and brains of miscarried fetuses with microcephaly. The World Health Organisation’s Director-General Dr Margaret Chan says a causal link is “strongly suspected”.

Why was the potential link between Zika and birth defects not previously observed?

In areas where Zika has been active for decades, such as Central Africa and Asia, most people are infected early in life, so the risk of infection during pregnancy is small.

The population in the Americas has not had exposure to the virus until now.

This means more women are now being exposed to the virus for the first time during pregnancy, possibly increasing the risk of birth defects.

This is why public health officials are telling women to avoid getting pregnant, at least until they have had the virus, or Zika has been brought under control.

Can GM mosquitos stop the virus?

British biotech company Oxitec has produced genetically modified Aedes aegyptimosquitoes by introduing two genes into its DNA.

One of them makes its eggs glow under UV light, helping with identification.

The other causes ithe mosquito’s offspring to die.

Oxitec says that by releasing the GM mosquitos into infected areas populations of Aedes aegypti can be reduced by more than 80 percent, thereby reducing transmission of Zika.

Oxitec says there is no way the mosquitos’ modified DNA can transfer into humans or other mammals and insects, but public fears over genetic modification mean the technique is controversial.

Source: Al Jazeera

Processed meats linked to cancer – study from WHO #NoMoreBacon

Credit: Flickr /CC BY-SA 2.0

You’ve probably seen today’s headlines, about the fact that processed meat has been classified as a ‘definite’ cause of cancer. And red meat is a ‘probable’ cause.

The decision – coordinated by a respected international body – has been so highly anticipated by the media that speculation about the announcement has been building since last week.

But a link between certain types of meat and some forms of cancer – notably bowel cancer – isn’t ‘new’ news – the evidence has been building for decades, and is supported by a lot of careful research.

Nevertheless, today’s announcement is significant. It comes from the International Agency for Research on Cancer (IARC) – a group of international experts who scrutinise the overall evidence – in this case more than 800 studies – on how likely certain things are to cause cancer. Their decisions carry a lot of clout, especially with governments and regulators.

But what does the finding – published here in the Lancet Oncology – mean in practice? How much meat is it sensible to eat? And how many cases of cancer are linked to meat consumption?

In this post, we’ll look at what IARC’s classification actually means, how red and processed meat affect cancer risk, and the likely size of this effect.

But before we move on, let’s be clear: yes, a prolonged high-meat diet isn’t terribly good for you. But a steak, bacon sandwich or sausage bap a few times a week probably isn’t much to worry about. And overall the risks are much lower than for other things linked to cancer – such as smoking.

What are ‘red’ and ‘processed’ meat?

First, let’s clear up some definitions.

‘Red’ meat is (as you might expect), any meat that’s a dark red colour before it’s cooked –  this obviously means meats like  beef and lamb, but also includes pork.

‘Processed’ meat is meat that’s not sold fresh, but instead has been cured, salted, smoked, or otherwise preserved in some way (so things like bacon, sausages, hot dogs, ham, salami, and pepperoni). But this doesn’t include fresh burgers or mince.

Both of these types of meat are distinct from ‘white’ meats, like fresh chicken or turkey, and fish (neither of which appear to increase your risk of cancer).

The evidence so far…

There’s now a large body of evidence that bowel cancer is more common among people who eat the most red and processed meat. As this evidence has steadily built up, we’ve blogged about itseveral times – and it’s covered on the NHS Choices website and by the World Cancer Research Fund (WCRF).

(There’s also growing evidence for a possible link to both stomach and pancreatic cancers, but this seems to be less clear cut than the link to bowel cancer.)

The most convincing overview of the evidence of a link to bowel cancer comes from a 2011 analysis by researchers at the WCRF, who combined the results of a number of previous studies, to try to get a clear sense of the overall picture.

They were able to group the data according to those who ate the most red and processed meat and those who ate the least. A key finding from the WCRF analysis is that red meat and processed meat aren’t equally harmful: processed meat is more strongly linked to bowel cancer than red meat.

The results showed that those who ate the most processed meat had around a 17 per cent higherrisk of developing bowel cancer, compared to those who ate the least.

‘17 per cent’ sounds like a fairly big number – but this is a ‘relative’ risk, so let’s put it into perspective, and convert it to absolute numbers. Remember these are all ball-park figures – everyone’s risk will be different as there are many different factors at play.

We know that, out of every 1000 people in the UK, about 61 will develop bowel cancer at some point in their lives. Those who eat the lowest amount of processed meat are likely to have a lower lifetime risk than the rest of the population (about 56 cases per 1000 low meat-eaters).

If this is correct, the WCRF’s analysis suggests that, among 1000 people who eat the most processed meat, you’d expect 66 to develop bowel cancer at some point in their lives – 10 more than the group who eat the least processed meat.

How does red and processed meat cause cancer?

Researchers are still trying to pin down exactly how red and processed meat cause cells to become cancerous, but the main culprits seem to be certain chemicals found in the meat itself.

In red meat, the problems seem to start when a chemical called haem – part of the red pigment in the blood, haemoglobin – is broken down in our gut to from a family of chemicals called N-nitroso compounds. These have been found to damage the cells that line the bowel, so other cells in the bowel lining have to replicate more in order to heal. And it’s this ‘extra’ replication that can increase the chance of errors developing in the cells’ DNA – the first step on the road to cancer.

On top of this, processed red meats contain chemicals that generate N-nitroso compounds in the gut, such as nitrite preservatives.

Cooking meat at high temperatures, such as grilling or barbequing, can also create chemicals in the meat that may increase the risk of cancer. These chemicals are generally produced in higher levels in red and processed meat compared to other meats.

But there are other theories too – some research has suggested that the iron in red meat could play a role, while others suggest the bacteria in the gut might play a supporting role too.

So despite what you may hear, it isn’t about the quality of the meat, or whether it’s from the local butcher or your supermarket. The evidence so far suggests that it’s probably the processing of the meat, or chemicals naturally present within it, that increases cancer risk.

What does this decision from IARC mean?

Whatever the underlying mechanism, there’s now sufficient evidence for IARC to rule that  processed meat ‘definitely’ causes cancer, and that red meat ‘probably’ causes cancer. But to really understand what this means (and doesn’t mean), you need to know a bit about IARC’s categories.

When IARC assesses the evidence on a particular cancer risk, it assigns it to one of several groups, which – as the graphic below shows – represent how confident they are that it causes cancer in people.

151026-IARC-Meat-rating-UPDATE2

Processed meat has been classified as a ‘definite’ cause of cancer (or Group 1 carcinogen) – the same group that includes smoking and alcohol. And red meat is a ‘probable’ cause of cancer (or a Group 2a carcinogen) – the same group as shift work. While this may sound alarming, it’s important to remember that these groups show how confident IARC is that red and processed meat cause cancer, not how much cancer they cause.

When we covered a previous IARC decision on diesel emissions, Professor David Phillips, one of our experts in the causes of cancer, summed it up beautifully:

IARC does ‘hazard identification’, not ‘risk assessment’. That sounds quite technical, but what it means is that IARC isn’t in the business of telling us how potent something is in causing cancer – only whether it does so or not.

To take an analogy, think of banana skins. They definitely can cause accidents – but in practice this doesn’t happen very often (unless you work in a banana factory). And the sort of harm you can come to from slipping on a banana skin isn’t generally as severe as, say, being in a car accident.

But under a hazard identification system like IARC’s, ‘banana skins’ and ‘cars’ would come under the same category – they both definitely do cause accidents.

– Professor David Phillips

To put things in perspective, let’s look at how red and processed meat stack up against smoking:

151026-Tobacco-vs-Meat-UPDATE

In 2011, scientists estimated that around 3 in every hundred cancers in the UK were due to eating too much red and processed meat (that’s around 8,800 cases every year). This compares against 64,500 cases every year caused by smoking (or 19 per cent of all cancers).

So what does this mean for mealtimes?

Does red and processed meat still have a place in a healthy diet?

None of this means that a single meat-based meal is ‘bad for you’. What it does mean is that regularly eating large amounts of red and processed meat, over a long period of time, is probably not the best approach if you’re aiming to live a long and healthy life. Meat is fine in moderation – it’s a good source of some nutrients such as protein, iron and zinc. It’s just about being sensible, and not eating too much, too often.

So how much is a ‘sensible’ amount of meat? This is a much trickier question to answer. The evidence so far doesn’t point to a particular amount that’s, in terms of cancer risk, likely to be ‘too much’. All we can say is that on the whole, the risk is lower the less you eat. Based on a  range of health considerations, the Government advises people who eat more than 90g (cooked weight) of red and/or processed meat a day should cut down to 70g or less.

But what do these portions actually look like?

151026-Too-much-meat-UPDATE

So if you’re someone who has a very meaty diet, and you’re worried about cancer, you may want to think about cutting down. That doesn’t mean you need to start stocking up on tofu, unless you want to, it just means trying to eat smaller and fewer portions (by adding in more vegetables, beans and pulses – remember the eatwell plate?), or choosing chicken or fish instead. As we said above, there’s no strong evidence linking fresh white meats such as chicken, turkey, or fish to any types of cancer.

So our advice on diet stays the same: eat plenty of fibre, fruit and vegetables; cut back on red and processed meat, and salt; and limit your alcohol intake. It might sound boring but it’s true: healthy living is all about moderation.

Except for smoking: that’s always bad for you.

World Immunization Week 2015 #GetVaccinated

Progress towards global vaccination targets for 2015 is far off-track with 1 in 5 children still missing out on routine life-saving immunizations that could avert 1.5 million deaths each year from preventable diseases. In the lead-up to World Immunization Week 2015 (24–30 April), WHO is calling for renewed efforts to get progress back on course. Read more.

We’ve discussed the importance of vaccination about a billion times on this blog.  World Immunization Week brings to light how important vaccination is for global health!

#Ebola update: First increase in ebola cases in 2015 in all 3 heavily impacted countries

whograph

Despite the recent good news out of West Africa showing weeks of decreases in Ebola case incidences, last week showed increases in ebola cases in Guinea, Liberia, and Sierra Leone (graph above modified from WHO situation report showing cases from Guinea, recent case count tallies below from CDC). More info and graphs from the other affected countries can be found at CDC, WHO. A news article from Reuters here.

cdc1

The recent increases in ebola cases are a reminder that the outbreak is still ongoing, and that trials for ebola treatments and vaccines are still as important as ever!

#Ebola Update: Outbreak may be subsiding – BUT after 21759 cases – 8668 deaths

popsci

This terrific popsci.com article highlights the role that international intervention played in slowing and reversing the West African Ebola outbreak. First off, lets not downplay the horribleness of the outbreak:

The havoc that Ebola is wreaking in West Africa cannot be understated. With a total of 21,200 people infected since March 2014, the disease is shredding the social fabric of Guinea, Sierra Leone, and Liberia, leaving 8,400 dead. People live in fear, afraid to shake others’ hands. Survivors are shunned, and those suspected of carrying the disease are being physically assaulted in some regions.

Scientific models showed late last summer that the Ebola outbreak could result in over a million cases without a strong international effort to curb it. Many governments and aid organizations did step up, and were likely responsible for proving the scientific models wrong… Colin Brown (who studies infectious diseases at King’s College London) puts it perfectly:

The models showed what could happen if there was a lack of international effort. We really don’t know what would have happened if the world hadn’t stepped up.

While the outbreak seems to be subsiding, the article also highlights the need for people and governments to not be complacent… not surprisingly.

Graphs showing the awesome downward trend of cases and deaths can be found in the article, or in the WHO situation reports here. Shout out to my cousin Jason, who shared this article with me!

The #Ebola Outbreak Continues in West Africa! New Case Counts and the safety trial for Merck-NewLink’s vaccine restarts

graph

Despite the dissipated interest by most media outlets in the US, the outbreak of Ebola in West Africa continues. The CDC and WHO have updated Ebola case counts for the West African countries impacted most by the outbreak. The number of deaths now exceeds 8,000.

201315A clinical trial testing the safety of an Ebola vaccine has had to undergo a change in dose. The trial in Geneva, is testing a vaccine made by Merck-NewLink, and was halted in early December.

The clinical trial of an Ebola vaccine developed by Merck and NewLink resumed on Monday at a lower dose after a pause to assess complaints of joint pains in some volunteers, the University of Geneva hospital said.

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