mosquitoes

Zika, the new health threat, is a virus spread by mosquitoes which burst onto the scene in 2016.

It causes only a mild illness and 80% of patients have no symptoms at all but it seems to be associated with disorders of the nervous system, particularly microcephaly in developing foetuses, a condition in which babies are born with small and poorly functioning brains which usually causes mental retardation.

Twenty one countries in the Caribbean, North and South America, including  Florida have been affected and women have been advised not get pregnant in some of these. It has spread on a massive scale in the Americas, where transmission was first detected in Brazil in May 2015. Large numbers of the mosquitoes which carry the virus and a lack of any natural immunity in the population is thought to be helping the infection to spread rapidly.

It was first discovered over 60 yrs ago in Africa but the link between microcephaly and infection was not noticed. This could be because health surveillance is very poor in these countries or because the majority of the population have had an infection in childhood. As a result, by the time girls get pregnant they have already developed resistance to the virus.

junior doctors strike no 2

Junior doctors in England took industrial action for the first time in 40 years.Over 76 per cent of junior doctors voted in the ballot, with 99.4 per cent voting yes. The medical profession overwhelmingly supported their juniors covering their work and joined them on the picket line. The Government declared that changes in the junior doctor contract came about because of statistics that showed increased mortality at the weekend. The Government sought to:

1) Extend “plain time”, the hours in which a trainee doctor receives standard pay, from 7am-7pm Monday to Friday to 7am-10pm every day except Sunday, though he later offered to make it 7pm on a Saturday. This is in order to create the seven day NHS   [normal working for throughout the week] without spending more .

2) To remove the obligation to work to the European Working Time Directive which limits the hours doctors can work. While there is some evidence that patients admitted at the weekend are more likely to die within 30 days, this is a complex issue which is has never been directly linked to junior doctor staff numbers.

Weekend mortality is bound to be greater because only emergency cases are admitted not routine cases. When this is taken to account the ‘weekend effect’ is much diminished and most doctors and experts believe that is is mainly due to a lack of access to investigations such as scans and consultant supervision. Stretching the existing workforce around 7 days may create more gaps during the week days and worsen patient services then.

genetic engineering

On a more positive note 2016 was the year when gene editing started to hold out exciting possiblities. CRISPR-Cas9 is a gene editing technique that uses the Cas9 protein and a strand of RNA to make breaks in strands of DNA.

Then new genetic code is then placed inside the breaks. This can allow the genetic code to be rewritten. It is powerful and reliable, quick and very cheap. CRISPR-Cas 9 “components” can be bought for $30.  Possible applications are numerous, this is why Science Magazine declared the technique its ‘Breakthrough of the Year!’ Researchers at Duke University in the US used CRISPR-Cas9 to delete DNA in mice that was preventing cells from producing a protein essential for muscle function. This causes a human equivalent disease called Duchenne’s Muscular Dystrophy. A virus was used to deliver DNA alterations into the cells of mice.When they injected the therapy directly into the legs of adult mice, it resulted in improved muscle strength. When they injected it into the bloodstream – tests showed improvements in muscles responsible for heart and lung function.

Earlier this year, a group in China announced it was the first to successfully edit the genome of a human embryo. The breakthrough at Sun Yat-sen University in Guangdong showed the errors in DNA that led to a blood disorder, beta thalassaemia, could be corrected in embryos. Gene editing has been used to make mosquitoes resistant to the malaria parasite which they transmit to humans and to make pig organs genetically similar to human organs.

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