Giuseppe
Emeritus
[Source: World Health Organization, full PDF document: (LINK). Edited.]
Influenza Update N? 198, 11 November 2013
Summary
(...)
Countries in the temperate zone of the northern hemisphere
North America
Overall influenza activity in North America remained at low levels throughout the region.
In Canada and the United States of America, influenza activity remained at interseasonal levels.
In Mexico influenza activity continued to be low after a period of two months (July ? August) with higher influenza activity, but ARI reports decreased slightly while pneumonia levels were similar to previous weeks.
Europe
Low levels of influenza activity in the WHO European Region continued, with only a few countries reporting sporadic influenza detections among samples from sentinel and non-sentinel sources. The number of hospitalizations due to severe acute respiratory infection (SARI) remained at an interseasonal level. None of the SARI cases tested so far was found positive for influenza virus.
Northern Africa and the Western and Central Asia region
Influenza activity was low in the Northern Africa and western and central Asia regions.
In Azerbaijan and Georgia, ILI activity increased since early September.
Sporadic influenza detections were reported in Azerbaijan, Israel and Pakistan.
Northern Asia
Influenza activity in the temperate region of Asia remained at interseasonal levels since late May.
In Mongolia, clinical respiratory illness activity began to increase since mid-August, but no influenza viruses were detected in this period.
(...)
Countries in the tropical zone
Tropical countries of the Americas/Central America and the Caribbean
Overall influenza activity in the Caribbbean and Central America was at low levels throughout the regions, however increased influenza B activity was noted in some countries.
Decreasing numbers of influenza A virus have been detected, but influenza transmission had largely come to an end in the last few weeks in these countries.
In Cuba, SARI-associated hospitalizations had increased as well as of influenza B virus detections, and in the Domonican Republic increased influenza B virus were reported as well.
In the remaining countries, co-circulation of influenza A(H3N2) and influenza B viruses were reported, and while RSV predominated among respiratory viruses in countries such as Costa Rica and El Salvador, low levels were reported overall.
(...)
In tropical South America, acute respiratory virus activity continued decreasing following a period of high influenza activity in July and August.
In Colombia, the proportions of outpatient visits, hospitalizations, and ICU admissions have shown a decreasing trend.
In Venezuela, ARI and pneumonia levels were reported within the expected values for the time of year.
In Ecuador the number of positive influenza samples steadily decreased since its influenza peak in August, and SARI activity continued a decreasing trend.
In the Plurinational State of Bolivia the proportion of SARI-related hospitalizations were reported as elevated compared to the data from the same period last year, especially in the eastern part of the country (Santa Cruz).
Brazil showed a continuing decline in the number of positive influenza samples since July.
Central African tropical region
Cote d?Ivoire, Ghana and Kenya reported influenza virus detections.
In Cote d?Ivoire influenza B and influenza A(H3N2) were the predominant viruses detected, but overall influenza activity had decreased.
Ghana reported primarily influenza A(H3N2) viruses but also cases of influenza B, and activity does not seem to present a clear peak over time.
Kenya reported low influenza activity comprised of influenza A(H1N1)pdm09, A(H3N2) and influenza B viruses.
(...)
Tropical Asia
Influenza transmission in southern Asia was low. Both influenza A(H1N1)pdm09 and A(H3N2) viruses were reported in this area.
A decrease in influenza transmission, the influenza associated hospital rates and ILI consultation rates was seen since early October in Hong Kong Special Administrative Region (SAR), China.
In the south of China, influenza activity decreased since early October.
Influenza A(H3N2) virus was the main virus subtype reported, but influenza A(H1N1)pdm09 and influenza B viruses were also detected.
(...)
Overall, influenza transmission in South East Asia remained at a moderate level.
Since early September, influenza activity increased in Lao People?s Democratic Republic, due to greater influenza A(H1N1)pdm09 and A(H3N2) transmission.
ILI activity decreased in Thailand since early September, but influenza detections were still at a slightly increased level.
In Viet Nam, a decrease was seen in the number of influenza positive ILI samples and the number of positive influenza samples since early-October.
Cambodia reported an increase in influenza activity since mid-September, mainly due to increased influenza B transmission.
(...)
Countries in the temperate zone of the southern hemisphere
Temperate countries of South America
In the temperate countries of South America, ARI activity was reported at expected levels for the time of year, with the exception of high ILI activity in Paraguay. Co-circulation of influenza A(H3N2) and influenza B viruses was reported in most countries.
RSV and parainfluenza continued to be the most common respiratory virus detected in Chile, although respiratory virus activity persisted with its decreasing trend.
In Paraguay, the ILI consultation rate was higher than expected for the time of year, but the rate had decreased from levels in previous weeks.
In Uruguay the proportion of SARI-associated hospitalizations remained at low levels.
(...)
Temperate countries of Southern Africa
After a peak in influenza activity in South Africa due to influenza A(H1N1)pmd09 in June, a small second peak continued to be observed in the last few weeks due to influenza A(H3N2) and influenza B circulation. While influenza cases reported were primarily influenza B, the South African influenza season appears to be over.
(...)
Oceania, Melanesia and Polynesia
Overall, in Australia, New Zealand and the Pacific Islands influenza activity decreased. In Australia and New Zealand, all indicators showed a downward trend indicating that the end of the season is near.
(...)
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 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? 198, 11 November 2013
Summary
- Although in many European countries influenza-like illness activity started to increase, influenza detections in the northern hemisphere temperate zones remained low.
- Influenza transmission in southern Asia was low.
- In Hong Kong Special Administrative Region, China, and in the south of China influenza detections decreased.
- In South East Asia, influenza activity decreased in Thailand and Viet Nam, but increased in Cambodia and Lao People?s Democratic Republic.
- In this area, co-circulation of influenza A(H1N1)pdm09, influenza A(H3N2) and influenza B virus was reported.
- In the Caribbean region of Central America and tropical South America countries, reported cases of influenza A infection remained at low levels among most Caribbean islands and Central American countries, with increased reports of influenza B in certain countries.
- Respiratory syncytial virus (RSV) continued to predominate in certain countries, but the RSV activity largely remained within expected seasonal levels.
- Influenza activity peaked in the temperate countries of South America and in South Africa in late June.
- Temperate South American countries reported cases of A(H1N1)pdm09 A (H3N2) and influenza B, and acute respiratory activity remained low.
- In Australia and New Zealand, numbers of influenza viruses detected and rates of influenza-like illness decreased.
- Co-circulation of influenza A(H1N1)pdm09, A(H3N2) and B viruses was reported in both countries.
(...)
Countries in the temperate zone of the northern hemisphere
North America
Overall influenza activity in North America remained at low levels throughout the region.
In Canada and the United States of America, influenza activity remained at interseasonal levels.
In Mexico influenza activity continued to be low after a period of two months (July ? August) with higher influenza activity, but ARI reports decreased slightly while pneumonia levels were similar to previous weeks.
Europe
Low levels of influenza activity in the WHO European Region continued, with only a few countries reporting sporadic influenza detections among samples from sentinel and non-sentinel sources. The number of hospitalizations due to severe acute respiratory infection (SARI) remained at an interseasonal level. None of the SARI cases tested so far was found positive for influenza virus.
Northern Africa and the Western and Central Asia region
Influenza activity was low in the Northern Africa and western and central Asia regions.
In Azerbaijan and Georgia, ILI activity increased since early September.
Sporadic influenza detections were reported in Azerbaijan, Israel and Pakistan.
Northern Asia
Influenza activity in the temperate region of Asia remained at interseasonal levels since late May.
In Mongolia, clinical respiratory illness activity began to increase since mid-August, but no influenza viruses were detected in this period.
(...)
Countries in the tropical zone
Tropical countries of the Americas/Central America and the Caribbean
Overall influenza activity in the Caribbbean and Central America was at low levels throughout the regions, however increased influenza B activity was noted in some countries.
Decreasing numbers of influenza A virus have been detected, but influenza transmission had largely come to an end in the last few weeks in these countries.
In Cuba, SARI-associated hospitalizations had increased as well as of influenza B virus detections, and in the Domonican Republic increased influenza B virus were reported as well.
In the remaining countries, co-circulation of influenza A(H3N2) and influenza B viruses were reported, and while RSV predominated among respiratory viruses in countries such as Costa Rica and El Salvador, low levels were reported overall.
(...)
In tropical South America, acute respiratory virus activity continued decreasing following a period of high influenza activity in July and August.
In Colombia, the proportions of outpatient visits, hospitalizations, and ICU admissions have shown a decreasing trend.
In Venezuela, ARI and pneumonia levels were reported within the expected values for the time of year.
In Ecuador the number of positive influenza samples steadily decreased since its influenza peak in August, and SARI activity continued a decreasing trend.
In the Plurinational State of Bolivia the proportion of SARI-related hospitalizations were reported as elevated compared to the data from the same period last year, especially in the eastern part of the country (Santa Cruz).
Brazil showed a continuing decline in the number of positive influenza samples since July.
Central African tropical region
Cote d?Ivoire, Ghana and Kenya reported influenza virus detections.
In Cote d?Ivoire influenza B and influenza A(H3N2) were the predominant viruses detected, but overall influenza activity had decreased.
Ghana reported primarily influenza A(H3N2) viruses but also cases of influenza B, and activity does not seem to present a clear peak over time.
Kenya reported low influenza activity comprised of influenza A(H1N1)pdm09, A(H3N2) and influenza B viruses.
(...)
Tropical Asia
Influenza transmission in southern Asia was low. Both influenza A(H1N1)pdm09 and A(H3N2) viruses were reported in this area.
A decrease in influenza transmission, the influenza associated hospital rates and ILI consultation rates was seen since early October in Hong Kong Special Administrative Region (SAR), China.
In the south of China, influenza activity decreased since early October.
Influenza A(H3N2) virus was the main virus subtype reported, but influenza A(H1N1)pdm09 and influenza B viruses were also detected.
(...)
Overall, influenza transmission in South East Asia remained at a moderate level.
Since early September, influenza activity increased in Lao People?s Democratic Republic, due to greater influenza A(H1N1)pdm09 and A(H3N2) transmission.
ILI activity decreased in Thailand since early September, but influenza detections were still at a slightly increased level.
In Viet Nam, a decrease was seen in the number of influenza positive ILI samples and the number of positive influenza samples since early-October.
Cambodia reported an increase in influenza activity since mid-September, mainly due to increased influenza B transmission.
(...)
Countries in the temperate zone of the southern hemisphere
Temperate countries of South America
In the temperate countries of South America, ARI activity was reported at expected levels for the time of year, with the exception of high ILI activity in Paraguay. Co-circulation of influenza A(H3N2) and influenza B viruses was reported in most countries.
RSV and parainfluenza continued to be the most common respiratory virus detected in Chile, although respiratory virus activity persisted with its decreasing trend.
In Paraguay, the ILI consultation rate was higher than expected for the time of year, but the rate had decreased from levels in previous weeks.
In Uruguay the proportion of SARI-associated hospitalizations remained at low levels.
(...)
Temperate countries of Southern Africa
After a peak in influenza activity in South Africa due to influenza A(H1N1)pmd09 in June, a small second peak continued to be observed in the last few weeks due to influenza A(H3N2) and influenza B circulation. While influenza cases reported were primarily influenza B, the South African influenza season appears to be over.
(...)
Oceania, Melanesia and Polynesia
Overall, in Australia, New Zealand and the Pacific Islands influenza activity decreased. In Australia and New Zealand, all indicators showed a downward trend indicating that the end of the season is near.
(...)
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 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
- 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/en/index.html
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