Memorandum by Global Influenza Surveillance
Network
3. There are the WHO systems: GOARN, the
global influenza surveillance network and FluNet.
Many countries now have thermal scanners at
points of entry. For example UAE will scan entrants and give febrile
individuals a rapid diagnostic test (looking particularly for
malaria). Infected individuals will be offered treatment. It is
not clear what an infected individual's options will be for entry
thereafter.
Proper consideration of the role of migration
on the spread of infectious disease is needed. It is not sensible
to let considerations of political correctness stop us from detecting
and treating infected and infectious migrants. Both for their
own good and for the good of the societies they join.
4. HIV/AIDS depends on how good drug distribution
programmes are and how at-risk populations change their behaviour.
The emergence of highly transmissible multi-drug resistant strains
will also have a high impact.
Avian influenza (or any emergent influenza).
The acquisition of the ability to transmit easily amongst humans
is a process so poorly understood that it has to be treated as
stochastic. It is not the case that H5N1 avian influenza is the
only threat, a new pandemic strain might arise from a different
genetic background that currently does not infect humans.
TB The increase in XDR TB needs to be followed
very carefully to assess the global threat.
Malaria. Discussion of eradication is widespread.
The problem is financial, not anything else. The Global Fund has
dispersed 2.4 billion in the last five years with a reasonable
match to malaria prevalence. In terms of financing what is needed
to move towards eradication things are in a good position. If
The Gates Foundation follows up their apparent interest in eradication
with substantial funds it may become a possibility.
7. For malaria global warming is often cited
as a risk factor for extensions in the range of spread. This is
probably a red herring and drug resistance has been a much more
important risk. Now that a new family of drugs (the artemisinins)
is available prevalence is falling across Africa.
The thought that global warming would bring
malaria back to N Europe pre-supposes a complete breakdown in
the health infrastructure.
9. TB has always been hard to treat. The
drugs have to be taken for a long time, including long after the
patient feels well. Many countries use directly observed treatment
strategies (dots) in which health workers visit patients every
day to watch them take their medicine. This is costly in terms
of man power, but can be very effective.
10. The adverse effects of DDT were from
agricultural applications, not malaria control. For malaria control
you would perform residual spraying to the inside of a hut. Janet
Hemingway at the Liverpool School of Hygiene would know about
this.
12. Different answers for different pathogens
HIV drug resistance is not yet the major reason
for continued spread.
TB drug resistance is an important contributor
to continued spread.
Malaria drug resistance has been the most important
factor in the past. If drug resistance to the new family of drugs
arises it will have enormous impact. MMV the medicine for malaria
initiative considers this possibility and seeks out new drugs
for the pipeline. Again we are in a better position than five
to 10 years ago.
Avian influenza is not spreading amongst humans
yet. However, I think it is extremely likely that an avian influenza
that became capable of efficient human-to-human spread would very
rapidly acquire drug resistance which would then render useless
our proposed drug-based control strategies.
16. The 2005 IHRs allow WHO to "use"
unofficial sources although it states that it will "verify
with countries before taking any action". This is an important
step forward as it allows WHO to (at least partially) benefit
from internet based sources of information. I assume you know
about Promed www.promedmail.org.
However the IHRs are largely about sharing information and expertise.
It would be a mistake to rely on them to prevent the spread of
infection. We would just know about it sooner and be able to help
a source country with interventions. That could stop a pandemic
for some infections but almost certainly won't for something like
pandemic influenza.
18. We think there is a real threat from
Dengue. Bacterial infections of childhood and from food are an
important and growing threat to health. Our past vaccines have
mostly remained effective for a long time. Newer vaccines may
be much less durable (because of differences in the underlying
biology of the pathogens they protect against). It would be prudent
to be aware that vaccine resistance may become a public health
problem in the future.
February 2008
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