ProMED-mail |

Published Date: 2010-06-05 23:50:00
Subject: PRO/AH/EDR> Influenza pandemic (H1N1) (39): WHO update 103
Archive Number: 20100605.1867

INFLUENZA PANDEMIC (H1N1) (39): WORLD HEALTH ORGANISATION UPDATE 103
********************************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>

Date: Fri 4 Jun 2010
Source: World Health Organisation (WHO), CSR, Disease Outbreak News [edited]
<http://www.who.int/csr/don/2010_06_04/en/index.html>

Influenza pandemic (H1N1) 2009 - update 103
-------------------------------------------
As of Sun 30 May 2010, worldwide more than 214 countries and overseas
territories or communities have reported laboratory confirmed cases
of pandemic influenza H1N1 2009, including more than 18 138 deaths.
The WHO is actively monitoring the progress of the pandemic through
frequent consultations with the WHO Regional Offices and Member
States and through monitoring of multiple sources of information.

Situation update:
-----------------
Active but declining transmission of pandemic influenza virus
continued to be detected in parts of the Caribbean and Southeast
Asia. In the countries of temperate southern hemisphere there is no
evidence yet to suggest that the winter influenza season has begun,
however there has been limited localized pandemic influenza virus
transmission in Chile. In the rest of the world, overall pandemic
influenza virus transmission remains low. Seasonal influenza B
viruses are currently the predominant type of influenza virus
circulating globally, although at low levels. Of note, during the
later part of May 2010, low but significant levels of predominantly
seasonal influenza H3N2 viruses have been detected in several
countries of East Africa.

In the tropical zone of the Americas, the most active areas of
pandemic influenza virus transmission continue to be in parts of the
Caribbean. In Cuba, pandemic influenza virus transmission has begun
to decline after plateauing since mid-April 2010. In both Costa Rica
and Columbia, there has been persistence of low level circulation of
pandemic influenza virus since the beginning of 2010. Sporadic
detections of pandemic and other seasonal influenza viruses,
particularly type B, have been reported from several countries in the
region during May 2010. Other respiratory viruses, for example RSV
[respiratory syncytial virus], are known to be circulating to varying
extents in different countries across the region.

In Asia, the most active areas of pandemic influenza virus
transmission currently are in parts of South and Southeast Asia,
particularly in Singapore and Malaysia, and to a lesser extent in
Bangladesh. In Singapore, during the last week of May 2010, levels of
ARI [acute respiratory infections] fell below the epidemic threshold
and the proportion of respiratory samples testing positive for
pandemic influenza fell from 39 percent to 29 percent. In Malaysia
and Bangladesh, the numbers of new cases reported per week have been
relative stable for the past 6 and 3 weeks, respectively, suggesting
stable persistence of low level pandemic virus circulation during the
past month in these areas. Very low levels of pandemic influenza
virus also continue to circulate in parts of western and southern
India, and in parts of Thailand. Sporadic detections of pandemic
influenza virus have been reported in many countries across the
region during the past month. In East Asia, overall influenza ac!
tivity remains low, however, seasonal influenza B viruses continue to
circulate at low and declining levels across the region.

In Sub-Saharan Africa, active but declining levels of pandemic
influenza virus transmission continue to be detected in parts of West
Africa, most notably in Ghana. During the most recent reporting week,
15 percent of all respiratory samples tested positive for pandemic
influenza virus in Ghana. Sporadic detections of seasonal influenza B
continue to be reported in central Africa. Of note, low but
significant numbers of seasonal H3N2 viruses were recently detected
in Kenya (6 of 57 respiratory samples tested) and Tanzania (13 of 25
respiratory samples tested) during the most recent reporting week.

Overall, in the temperate regions of the northern and southern
hemisphere, pandemic influenza viruses have been detected only
sporadically during the past month. In the temperate southern
hemisphere, Chile is the only country to recently report a small
number of pandemic influenza cases in a few areas of the country
suggesting that overall transmission is currently limited. Other
respiratory viruses, most notably RSV, are known to be circulating in
Chile, Paraguay, and Argentina. There have been no recent detections
of pandemic influenza virus in South Africa. In New Zealand and
Australia, overall levels of ILI [influenza-like illness] remain low;
only sporadic detections of seasonal and pandemic influenza viruses
have been recently reported in Australia.

The Global Influenza Surveillance Network (GISN) continues monitoring
the global circulation of influenza viruses, including pandemic,
seasonal and other influenza viruses infecting, or with the potential
to infect, humans including seasonal influenza. For more information
on virological surveillance and antiviral resistance please see the
weekly virology update (Virological surveillance data
<http://www.who.int/csr/disease/swineflu/laboratory4_06_2010/en/index.html>)
and the Weekly update on oseltamivir resistance to pandemic influenza
A (H1N1) 2009 viruses.

As of Wed 2 Jun 2010, for this reporting week (26 May to 02 Jun
2010), 2 additional cases of oseltamivir resistant pandemic influenza
A (H1N1) 2009 viruses have been reported. This brings the cumulative
total to 2921 so far. All but one* of these have the H275Y
substitution and are assumed to remain sensitive to zanamivir. (See
the Weekly update on oseltamivir resistance to pandemic influenza A
(H1N1) 2009 viruses at
<http://www.who.int/csr/disease/swineflu/oseltamivirresistant20100604.pdf>.

* The WHO Euro region report a case of pandemic A(H1N1) 2009 virus
that developed in an immunocompromised child with reduced
susceptibility to zanamivir and oseltamivir due to an amino-acid
mutation at position 223 in the neuraminidase. The clinical
implications of this A(H1N1) 2009 variant are being assessed and a
publication is expected. The report is available at:
<http://www.euroflu.org/cgi-files/bulletin_v2.cgi>.

Case count
----------
The countries and overseas territories/communities that have newly
reported their 1st pandemic (H1N1) 2009 confirmed cases since the
last web update (No. 102): none.

The countries and overseas territories/communities that have newly
reported their 1st deaths among pandemic (H1N1) 2009 confirmed cases
since the last web update (No. 102): none.

Region / Deaths*
----------------
WHO Regional Office for Africa (AFRO) / 168
WHO Regional Office for the Americas (AMRO) / At least 8410
WHO Regional Office for the Eastern Mediterranean(EMRO) / 1019
WHO Regional Office for Europe (EURO) / At least 4878
WHO Regional Office for South-East Asia (SEARO) / 1825
WHO Regional Office for the Western Pacific (WPRO) / 1837
Total* / At least 18138

* The reported number of fatal cases is an under representation of
the actual numbers as many deaths are never tested or recognized as
influenza related.

Since the last update on 23 May 2010 the number of fatalities has
increased by at least 24.

--
Communicated by:
ProMED-mail Rapporteur Marianne Hopp

[Active but declining transmission of pandemic influenza virus
continued to be detected in parts of the Caribbean and Southeast
Asia. In the countries of temperate southern hemisphere there is no
evidence yet to suggest that the winter influenza season has begun.
In the rest of the world, overall pandemic influenza virus
transmission remains low. Seasonal influenza B viruses are currently
the predominant type of influenza virus circulating globally,
although at low levels.

A map of influenza activity and virus subtypes is accessible at:
<http://www.who.int/csr/disease/swineflu/FluTransmissionZones_2010_06_04.png>.
The displayed data reflect the most recent data reported to FluNet
(<http://gamapserver.who.int/GlobalAtlas/home.asp>), WHO regional
offices or on Ministry of health websites in the last 2 weeks. The
full text of the WHO update should be consulted for other relevant
links. - Mod.CP]

See Also