A recent trial published online in the Lancet has
shown that a new vaccine against Ebola virus is 100% effective in the
people it has been tested. It is being said that this may go down in
history as one of those hallmark public health efforts which will be
taught about in public health schools eternally.
The vaccine (rVSV-ZEBOV) was developed using an
attenuated vesicular stomatitis virus (VSV) which was engineered to
produce an Ebola protein. The Guinea trial – called ‘Ebola, ça suffit’
in French (‘Ebola, that’s enough’) – used a daring and pragmatic design,
which allowed the researchers to assess this vaccine in the midst of an
epidemic. They borrowed a strategy from the small pox vaccination
program of the 1970’s – the ring vaccination. The trial had two arms. In
the first, adults who had been in contact with confirmed cases of Ebola
were vaccinated within 10 days of exposure. In the second, the contacts
were vaccinated after 3 weeks of exposure. None of the 2014 adults
vaccinated within 10 days of contact with an Ebola patient developed the
disease while 16 people who were vaccinated after 3 weeks of contact
developed the disease. On the basis of these results, all contacts are
now being given an immediate vaccination. Guinea’s Ebola cases have
started reducing, and this vaccine offers a lot of hope that the
epidemic may soon end.
Why is this trial so important? Ring vaccination has
never been used in a formal vaccine trial design. If researchers had
used the standard garden variety of randomized control trial, they would
have to enrol many more people, and it would have taken lot more time to
demonstrate any statistically significant finding. This study not only
showed efficacy of a vaccine in a phase III trial, but also helped to
control an epidemic. (Nature news 31 July 2015)
Error of Judgment is not Medical Negligence
In a recent ruling, the National Consumer Disputes
Redressal Commission has made an important distinction between error of
judgment vis-a-vis medical negligence. The complainant charged a
doctor in New Delhi with medical negligence for diagnosing tuberculosis
when he was subsequently found to have lung cancer with metastasis. The
Commission noted that the patient was a heavy smoker and drug addict,
and had earlier received treatment for testicular tuberculosis. Advice
for investigations and biopsy of the lesion were not followed, and he
did not follow-up in the hospital for eight months. The Panel ruled that
it was the negligence of the patient for which the doctor is not
responsible. In the current atmosphere of distrust and litigation, this
is a sweet relief for beleaguered doctors. (The Hindu 21 July 2015)
Reducing Arsenic in Rice
The risk of arsenic poisoning is highest for people
whose staple diet is rice. Rice is grown in flooded paddy fields.
Arsenic occurs naturally in water and soil, and rice has a higher
propensity to take up arsenic. Conventionally rice is cooked in water
till all the water is soaked up and the arsenic gets bound to the rice.
Plant and soil scientists in Belfast (UK), decided to try a new method
to cook rice. They found that thoroughly rinsing the rice and cooking it
in excessive amounts of water which is progressively discarded helps to
reduce the arsenic in rice. They found using a ratio of 12 parts water
to one part rice reduces the arsenic by 57%. They then cooked rice in an
apparatus that continually condenses steam to produce a fresh supply of
distilled hot water, and in an ordinary coffee percolator with a filter,
which allows cooking water to drip out of the rice. Testing the rice
before and after cooking showed that coffee-pot percolation removed
about half the arsenic, and that the laboratory apparatus removed around
60-70%.
This finding may be particularly important for places
like Bangladesh where rice is a staple food and the water is naturally
high in arsenic. There parboiling is done on a commercial scale, and may
offer an opportunity to intervene and reduce arsenic levels. The
technique may also help to reduce arsenic in commercial baby foods which
use pre-cooked rice. (Nature news 22 July 2015)
For HIV, Treatment is Prevention!
Close on the heels of several large trials
documenting that early treatment is beneficial for patients with HIV,
the WHO is now working towards a recommendation that all patients with
HIV receive early treatment. One of the trials (HPTN 052) tested the
hypothesis that treating a patient early after diagnosis will reduce the
risk of transmission to his partner. In this study, there was an
impressive 96% reduction in transmission to the partner. This led to a
change in the protocol of the study where treatment was also offered to
the control group. In the 4-year follow-up analysis, the results are
still very significant with a 93% reduction in risk of transmission to
the partner. Another important trial (START) has shown that very early
treatment can reduce the risk of serious infection and death in patients
by 57%.
Early treatment appears to have benefits for the patient with HIV,
and also plays a key role in preventing transmission. The long time
dilemma about whether our focus should be treatment or prevention seems
to have ended. As it is very succinctly being put – treatment is
prevention. (Nature news 20 July 2015)