A CABI sales colleague now in Argentina reported on June 30th that meetings had
been cancelled, ministers were resigning and hospitals & schools faced closure,
all through the fear of the novel H1N1 influenza pandemic the entire world is
now experiencing.
The Argentine Post points out that Argentina is now entering its winter, and that
the “number of cases stand at 1587 and deaths at 26 (June 26)”. For June 29,
the WHO states that laboratory confirmed cumulative cases and deaths are 1488
and 23, so I think the writer of the Post piece added cumulative numbers to the
newly reported ones for June 26.
Be that as it may, the WHO figures put Argentina 7th in global rank of number of
cases (USA and Mexico are 1 and 2) and 3rd in number of deaths (Colombia and
Mexico are 1 and 2). Experts tell us that influenza is a virus that prefers the
winter season in temperate regions… though it must be a considerably warmer winter
in Argentina compared to the UK.
There are other figures in the Argentine Post piece – death rates calculated for
Argentina, Chile and Mexico but they forgot to convert their figures correctly
to get %. By my calculations, the true figure for death rate in Argentina is
1.6% (not 0.016%!), which means it is experiencing a similar death rate from
this strain of flu to that of Mexico (1.4%). Only Colombia (2.7%) outdoes these
two countries for death rate from this flu strain, though it has less than a
hundred confirmed cases.
No wonder a health minister in Argentina, faced with figures like this and the
general belief that the case numbers were actually far worse, resigned…
Why are Argentina, Chile & Colombia so hard hit? Its worth considering how they
fare with seasonal influenza. According to PAHO, in 1999, the death rate for
children under 5 years from pneumonia and influenza was 3.6% (Argentina), 1.3%
(Chile) and 10.8% (Colombia). This compares to 1.4% for the USA in 1999. All
three countries run vaccination campaigns for infants and the elderly, but
Colombia only introduced theirs in 2005.
You can see from these figures that Colombians are in general more
susceptible to influenza…whether this is due to lack of access to healthcare or genetics (viral or human), I cannot say.
AS of July 2 2009, the Argentine government is in full disease prevention mode.
All pregnant women are being given 2 weeks leave from work immediately, free
treatment is offered for those with symptoms whatever their insurance status,
TV programs are educating the public in how to hand-wash correctly, make
face masks, and how to greet people without hugs and handshakes…use a formal
Japanese style bow!
Here in the UK, its serious enough to issue advice to schools to pass onto parents
but there is no panic.
The advice includes to sneeze into paper tissues, discard immediately, then wash
your hands …BUT meanwhile all these possibly infected tissues will be sitting
in the communal bins in offices, on the street or festering away in the
fortnightly recyclable waste bin…or should used tissues not be recycled? How long does this type of envelope virus
remain viable? I have an answer..it depends on absolute humidity and on the presence of nasal mucus. Influenza viruses, in the presence of nasal mucus, can survive for up to 48 hours on banknotes (!)(1): other studies suggest only 6-8 hours on metal surfaces and just 15 minutes on a tissue but I believe these tested pure viral cultures. Having the mucus there prolonged survival in a third of samples to 48 hours. Low absolute humidity favours both survival and transmission(2)…which is why flu outbreaks occur in winter.
Will dustmen start wearing facemasks? What about all those trees fated to end up as
paper tissues? Is there a bin which comes with disinfectant spray which treats
the tissues on a regular basis? Those of us who have worked in laboratories,
remember the bins of diluted bleach or disinfectant on hand to disinfect used
pipettes, but health & safety out in the normal world dictates it will have
to be more sophisticated than that.
Lets enter the world of Global Health and see what we can find out about influenza outbreaks in Latin America and some answers to how the individual can reduce transmission (apart from staying at home).
References
- Survival of influenza virus on
banknotes. Thomas Y. et al. Applied and Environmental
Microbiology (2008), 74, 10, 3002-3007 - Absolute
humidity modulates influenza survival, transmission, and seasonality. Shamani J. & Kohnb, M. PNAS (2009)early
edition DOI: 10.1073/pnas.0806852106 - Epidemiological study of influenza
virus infections in young adult outpatients from Buenos Aires, Argentina SantamarĂa, C. et al. J. Influenza and other
Respiratory Viruses 2008 Vol. 2 No. 4 pp. 131-134 - School closure to reduce
influenza transmission. Koonin, L.. M. & Cetron, M. S. ,Emerging
Infectious Diseases (2009), 15, 1, 137-138, correspondence (links to
Global Health, subscribers only)