January 3, 2013
Polio free does not mean paralysis free
N. GOPAL RAJ
There
is no room for complacency that India has eliminated this crippling disease as
Uttar Pradesh and Bihar have recorded a high incidence of a condition
symptomatic of it
Identifying
children who suddenly display muscle weakness, often not moving one or more of
their limbs as a result, forms the cornerstone of polio surveillance. Such
children could have “acute flaccid paralysis” (AFP) that is symptomatic of
polio, a disease caused by a virus. But AFP can also arise for other reasons,
including infection by non-polio pathogens.
No child in India
has been diagnosed with polio for nearly two years now and all the indications
are that the virus responsible for it is no longer circulating here. However,
the country’s polio surveillance system has indicated a sharp increase during
recent years in the number of non-polio AFP cases.
Alarming
data
Data published by
the World Health Organisation show that close to 8,000 non-polio AFP cases were
identified in India during 2003. They went up to over 12,000 the following
year, more than 26,000 in 2005 and crossed 40,000 by 2007. In 2011, there were
more than 60,000 non-polio AFP cases.
A good polio
surveillance system ought to pick up all AFP cases among children so that they
can be screened for poliovirus infection. On average, only about one child out
of every 200 children carrying the poliovirus develops AFP. Such cases must be
identified so that appropriate immunisation measures can be undertaken.
India’s polio
surveillance shows that the country is polio-free. But it also indicates that
the country now has the world’s highest rate of non-polio AFP cases. According
to data published in WHO’s Weekly Epidemiological Record, India’s annualised non-polio AFP rate for 2011
stood at 15.06 per one lakh children below 15 years of age, compared to a
global rate that year of 5.48.
Moreover, most of
the country’s non-polio AFP cases occur in just two States — Bihar and Uttar
Pradesh. They accounted for about 61 per cent of the 53,000-odd non-polio AFP
cases identified in the country in 2012, according to data from WHO’s National
Polio Surveillance Project. As a result, the two States have far higher
annualised non-polio AFP rates than other States — around 34 for Bihar and
about 23 for Uttar Pradesh. The rate for the country as a whole is slightly
over 12.
“The increased
non-polio AFP rate is due to increased reporting of AFP cases due to deliberate
efforts of the programme to increase the sensitivity of the surveillance system
since 2004,” according to the WHO Country Office for India. In a written
response provided to this correspondent, the health body said these efforts
were more intense and closely monitored in the traditionally polio-endemic
states of Bihar and U.P., resulting in even higher rates of reporting of AFP
cases in those States.
In 2004, a number
of steps were initiated to strengthen surveillance in order to accurately and
more rapidly detect all polio cases in the country, it said. Those measures
included expanding the definition of AFP; increasing the number of AFP
reporting sites; increasing the number of active surveillance visits; and more
training for health professionals on what constituted an AFP case.
Since then, the
number of AFP cases that were reported and investigated continued to increase,
it noted. This was not due to an increase in the incidence of a specific
disease that might cause these symptoms. Rather, it was the direct result of
surveillance activities for AFP cases being strengthened.
The programme in
India had taken a much broader interpretation of what would qualify as an AFP
case than other countries have. Although facial paralysis would not be part of
a standard definition of AFP, it was included in that definition for India.
Other similar examples were diseases like meningo-encephalitis, Bells palsy,
post-diphtheria polyneuritis and spinal muscular atrophy. Data had shown that
broadening the case definition led to the detection of some polio cases that
would have otherwise been missed, the WHO Country Office noted.
Moreover, in the
remaining polio-endemic countries of Nigeria, Pakistan and Afghanistan too,
efforts to strengthen polio surveillance were resulting in increased non-polio
AFP cases being reported, it added.
The high non-polio
AFP rates in the country ought to be a “red flag”, remarked T. Jacob John, a
leading virologist who was with Christian Medical College, Vellore, and is
known for his work on polio eradication.
With heightened
polio surveillance, sick children with suspected paralysis or possible
neurological maladies were being identified and tested by the polio
surveillance system, he remarked. However, the neurological disorders given by
the WHO Country Office as examples of the expanded definition of AFP were
likely to account for only a small part of the increase in non-polio AFP cases
being seen in India.
No
clear picture
Unfortunately, the
cases of children with non-polio AFP were not being monitored by either the
polio eradication programme or the larger state health care system. As a
result, there was no clear picture of what was causing the AFP, the kind of
diseases these children displayed, or how many of them were seriously affected,
he pointed out.
A range of
non-polio pathogens could produce AFP, said Dr. John. With many such pathogens,
the paralysis they caused would often disappear in a short period of time.
However, others were capable of causing quite serious diseases, disability and
even death.
Two teams of Indian
scientists recently studied the sorts of enteroviruses found in children with
non-polio AFP. Enteroviruses are a diverse group, most of which replicate in
the alimentary tract. The poliovirus is part of this group. Several non-polio
enteroviruses have been associated with a range of acute and chronic human
diseases, including polio-like paralysis.
In a study
published in 2009, a team at the Sanjay Gandhi Postgraduate Institute of
Medical Sciences in Lucknow tested over 46,000 stool samples from children with
AFP in U.P., Bihar and other northern States between 2004 and 2007. In the
other study, C. Durga Rao of the Indian Institute of Science, Bangalore, and
his colleagues looked for enteroviruses in stool samples collected from more
than 2,700 children with non-polio AFP in Kerala, Karnataka and Uttar Pradesh
between 2007 and 2009.
Enteroviruses
Both groups found
that only about 30 per cent of the non-polio AFP cases were associated with
enteroviruses. These viruses could therefore only partially explain the
non-polio AFP cases being detected.
In a paper
published early last year in the Indian
Journal of Medical Ethics, Neetu Vashisht
and Jacob Puliyel of the St. Stephens Hospital, Delhi, gave another perspective
on the issue. Children in Bihar and U.P. have received more doses of oral polio
vaccine than elsewhere in the country. The oral vaccine, it was found, became
less efficacious in the face of gut infections and diarrhoea that were widely
prevalent in those States.
In their paper, Dr.
Vashisht and Dr. Puliyel analysed the non-polio AFP rates across all States
over 10 years up to 2010, and found that the rate “increased in proportion to
the number of polio vaccine doses received in each area.” In 2012, the number
of doses of oral vaccine given to children in Bihar and U.P. had come down and,
for the first time, there was a decrease in the non-polio AFP cases in those
States, Dr. Puliyel told this correspondent.
There was need for
“a critical appraisal to find the factors contributing to the increase in
non-polio AFP with increase in OPV [oral polio vaccine] doses — perhaps looking
at the influence of strain shifts of entero-pathogens induced by the vaccine,”
said Dr. Vashisht and Dr. Puliyel in the paper.
The non-polio AFP
rate was not correlated with the number of oral vaccine doses that were
administered, countered the WHO Country Office in its response. The largest
number of oral vaccine doses given in India was in 2004, which had the lowest
non-polio AFP rate in the last eight years. Moreover, although the number of
oral vaccine doses given in the country had shown a continuous decline since
2007, the non-polio AFP rate had increased during the same period. In Bihar and
U.P. too, there were similar trends of reduced oral vaccine doses and rising
AFP rates during 2007-2011.
“The ICMR [Indian
Council of Medical Research] is leading the investigations into non-polio
causes of AFP,” the WHO Country Office stated.
I wish very happy new year to all of readers. We
have won a crusade like polio. But there is another enemy have appeared like
AFP. We should also aware of this challenging disease. And government should
take a serious step to eradicate it. As we surmount polio, we also surmount
AFP.
from: AMIT KUMAR SHUKLA
Posted
on: Jan 3, 2013 at 15:43 IST
This is an
eye-opener. Though India has been declare polio-free, we do
want any other epidemic out there to hurt out children. Non-Polio AFP
seems to be the next epidemic, if left unchecked. There is an urgent
need to find the root causes behind AFP and eliminate them. We should
not let AFP become the next Polio type disease.
want any other epidemic out there to hurt out children. Non-Polio AFP
seems to be the next epidemic, if left unchecked. There is an urgent
need to find the root causes behind AFP and eliminate them. We should
not let AFP become the next Polio type disease.
from: Manas
Posted
on: Jan 3, 2013 at 14:38 IST
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