Giuseppe
Emeritus
[Source: World Health Organization, full PDF document: (LINK). Edited.]
Influenza Update N? 203, 27 January 2014
Summary
The WHO GISRS laboratories tested more than 81 261 specimens.
24 494 were positive for influenza viruses, of which 22 425 (91.6%) were typed as influenza A and 2069 (8.4%) as influenza B.
Of the sub-typed influenza A viruses, 11 033 (80.5%) were influenza A(H1N1)pdm09 and 2669 (19.5%) were influenza A(H3N2).
Of the characterized B viruses, 220 (84%) belonged to the B-Yamagata lineage and 42 (16%) to the B-Victoria lineage.
For updates on human infections with avian influenza A(H7N9) virus see the WHO website http://www.who.int/influenza/human_animal_interface/influenza_h7n9/
(...)
Countries in the temperate zone of the northern hemisphere
North America
In North America, influenza activity remained high with A(H1N1)pdm09 the predominant virus detected. This differs from the 2012-2013 season when A(H3N2) was predominant.
Canada continued to experience increased influenza activity. Canadian surveillance data from laboratory detections, hospitalizations, and antiviral prescriptions show a larger proportion of cases among 20-64 year olds compared to those >65, which is a change from the 2012-2013 season. Over 90% of laboratory detections this season have been A(H1N1)pdm09, compared to 10% in 2012-13.
In the United States of America (USA), influenza activity remained high. In the second week of January the proportion of outpatient visits for influenza-like illness (ILI), was 3.6%, which is above the national baseline of 2.0%.
Most regions reported widespread geographic spread of influenza, and ILI activity was high in several southern and south western states.
The proportion of deaths attributed to pneumonia and influenza (P&I) was above the epidemic threshold, and ten paediatric deaths were attributed to influenza.
The proportion of ICU admissions for influenza was 19.4% of those hospitalized compared to 15.7%, 16.6% and 18% in previous seasons.
Of the tested specimens in the USA, influenza A was the predominant virus, and A(H1N1)pdm09 was the subtype detected most frequently.
(...)
Europe
In the European region, influenza activity increased in the beginning fo January compared to recent weeks, which may indicate the beginning of the influenza season.
Influenza A(H1N1)pdm09 and A(H3N2) viruses circulated throughout the region with variability in predominance among different countries. Consultation rates for ILI and acute respiratory infection (ARI) remained at low levels in most countries.
Increasing numbers of hospitalised laboratory-confirmed and fatal influenza cases have been reported in the last few weeks in western European countries.
Bulgaria, Greece, Portugal and Spain reported medium intensity of influenza and Portugal, Spain and the United Kingdom reported geographically widespread activity.
Of the specimens reported to WHO EURO, influenza A viruses remained predominant, accounting for 95% of tested samples. Of the subtyped A influenza viruses, 45% were A(H1N1)pdm09 and 55% A(H3N2).
(...)
Northern Africa and the Western and Central Asia region
In Central and Western Asia, increased influenza A(H3N2) activity was reported from Islamic Republic of Iran and Turkey in beginning of January.
Egypt experienced an increase in A(H1N1)pdm09 activity, and Turkey experienced increases of A(H3N2) activity. Influenza activity remained low in the remainder of the region.
Eastern Asia
In the Asian region in the beginning of January, A(H1N1)pdm09 viruses were the predominant subtype detected with increased influenza activity reported in China, Japan and the Republic of Korea .
In China, the influenza activity in both the south and north remained at high levels and was still increasing. The dominant subtypes of influenza viruses detected were A(H3N2) and A(H1N1)pdm09 in south China, and A(H1N1)pdm09 in north China.
In the Republic of Korea, the proportion of patients who visited sentinel physicians for ILI remained was at 27.3% which is above the national baseline of 12.1%.
Countries in the tropical zone
Tropical countries of the Americas/Central America and the Caribbean
Overall influenza activity in the Caribbean, Central America and tropical areas of South America was at low levels.
Central African tropical region
In the African region, influenza activity was generally low. A(H3N2) and influenza B viruses co-circulated in Ethiopia and Ghana while influenza B was detected in low numbers in West Africa.
Tropical Asia
Influenza activity among South-East Asia countries was generally low. In the Pacific Islands, overall there was a decrease in or low ILI activity.
Only the Federated States of Micronesia has reported sustained ILI levels for the past several weeks.
Countries in the temperate zone of the southern hemisphere
In the Southern Hemisphere ILI activity remained relatively low, with low level circulation of influenza A(H1N1)pdm09, A(H3N2)and influenza B.
(...)
Source of data
The Global Influenza Programme monitors influenza activity worldwide and publishes an update every two weeks.
The updates are based on available epidemiological and virological data sources, including FluNet (reported by the WHO Global Influenza Surveillance and Response System) and influenza reports from WHO Regional Offices and Member States. Completeness can vary among updates due to availability and quality of data available at the time when the update is developed.
Link to web pages
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Influenza Update N? 203, 27 January 2014
Summary
- In North America influenza activity remained high in recent weeks with A(H1N1)pdm09 predominant.
- In Europe, a slight increase in influenza activity has been observed, which may indicate the start of the influenza season.
- In China influenza activity continued to increase with influenza (H1N1)pdm09, A(H3N2) and influenza B co-circulating.
- In the southern hemisphere influenza activity remained low.
- In countries of tropical areas variable influenza activity was reported.
The WHO GISRS laboratories tested more than 81 261 specimens.
24 494 were positive for influenza viruses, of which 22 425 (91.6%) were typed as influenza A and 2069 (8.4%) as influenza B.
Of the sub-typed influenza A viruses, 11 033 (80.5%) were influenza A(H1N1)pdm09 and 2669 (19.5%) were influenza A(H3N2).
Of the characterized B viruses, 220 (84%) belonged to the B-Yamagata lineage and 42 (16%) to the B-Victoria lineage.
For updates on human infections with avian influenza A(H7N9) virus see the WHO website http://www.who.int/influenza/human_animal_interface/influenza_h7n9/
(...)
Countries in the temperate zone of the northern hemisphere
North America
In North America, influenza activity remained high with A(H1N1)pdm09 the predominant virus detected. This differs from the 2012-2013 season when A(H3N2) was predominant.
Canada continued to experience increased influenza activity. Canadian surveillance data from laboratory detections, hospitalizations, and antiviral prescriptions show a larger proportion of cases among 20-64 year olds compared to those >65, which is a change from the 2012-2013 season. Over 90% of laboratory detections this season have been A(H1N1)pdm09, compared to 10% in 2012-13.
In the United States of America (USA), influenza activity remained high. In the second week of January the proportion of outpatient visits for influenza-like illness (ILI), was 3.6%, which is above the national baseline of 2.0%.
Most regions reported widespread geographic spread of influenza, and ILI activity was high in several southern and south western states.
The proportion of deaths attributed to pneumonia and influenza (P&I) was above the epidemic threshold, and ten paediatric deaths were attributed to influenza.
The proportion of ICU admissions for influenza was 19.4% of those hospitalized compared to 15.7%, 16.6% and 18% in previous seasons.
Of the tested specimens in the USA, influenza A was the predominant virus, and A(H1N1)pdm09 was the subtype detected most frequently.
(...)
Europe
In the European region, influenza activity increased in the beginning fo January compared to recent weeks, which may indicate the beginning of the influenza season.
Influenza A(H1N1)pdm09 and A(H3N2) viruses circulated throughout the region with variability in predominance among different countries. Consultation rates for ILI and acute respiratory infection (ARI) remained at low levels in most countries.
Increasing numbers of hospitalised laboratory-confirmed and fatal influenza cases have been reported in the last few weeks in western European countries.
Bulgaria, Greece, Portugal and Spain reported medium intensity of influenza and Portugal, Spain and the United Kingdom reported geographically widespread activity.
Of the specimens reported to WHO EURO, influenza A viruses remained predominant, accounting for 95% of tested samples. Of the subtyped A influenza viruses, 45% were A(H1N1)pdm09 and 55% A(H3N2).
(...)
Northern Africa and the Western and Central Asia region
In Central and Western Asia, increased influenza A(H3N2) activity was reported from Islamic Republic of Iran and Turkey in beginning of January.
Egypt experienced an increase in A(H1N1)pdm09 activity, and Turkey experienced increases of A(H3N2) activity. Influenza activity remained low in the remainder of the region.
Eastern Asia
In the Asian region in the beginning of January, A(H1N1)pdm09 viruses were the predominant subtype detected with increased influenza activity reported in China, Japan and the Republic of Korea .
In China, the influenza activity in both the south and north remained at high levels and was still increasing. The dominant subtypes of influenza viruses detected were A(H3N2) and A(H1N1)pdm09 in south China, and A(H1N1)pdm09 in north China.
In the Republic of Korea, the proportion of patients who visited sentinel physicians for ILI remained was at 27.3% which is above the national baseline of 12.1%.
Countries in the tropical zone
Tropical countries of the Americas/Central America and the Caribbean
Overall influenza activity in the Caribbean, Central America and tropical areas of South America was at low levels.
Central African tropical region
In the African region, influenza activity was generally low. A(H3N2) and influenza B viruses co-circulated in Ethiopia and Ghana while influenza B was detected in low numbers in West Africa.
Tropical Asia
Influenza activity among South-East Asia countries was generally low. In the Pacific Islands, overall there was a decrease in or low ILI activity.
Only the Federated States of Micronesia has reported sustained ILI levels for the past several weeks.
Countries in the temperate zone of the southern hemisphere
In the Southern Hemisphere ILI activity remained relatively low, with low level circulation of influenza A(H1N1)pdm09, A(H3N2)and influenza B.
(...)
Source of data
The Global Influenza Programme monitors influenza activity worldwide and publishes an update every two weeks.
The updates are based on available epidemiological and virological data sources, including FluNet (reported by the WHO Global Influenza Surveillance and Response System) and influenza reports from WHO Regional Offices and Member States. Completeness can vary among updates due to availability and quality of data available at the time when the update is developed.
Link to web pages
- Influenza reports from WHO Regional Offices:
- Epidemiological Influenza updates: http://www.who.int/influenza/surveillance_monitoring/updates/latest_update_GIP_surveillance
- Epidemiological Influenza updates archives 2012: http://www.who.int/influenza/surveillance_monitoring/updates/GIP_surveillance_2012_archives
- Virological surveillance updates : http://www.who.int/influenza/gisrs_laboratory/updates/summaryreport
- Virological surveillance updates archives : http://www.who.int/influenza/gisrs_laboratory/updates/
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