tetano
Editor, Senior Moderator
Bull World Health Organ. 2014 May 1;92(5):318-30. doi: 10.2471/BLT.13.124412. Epub 2014 Feb 24.
Influenza seasonality and vaccination timing in tropical and subtropical areas of southern and south-eastern Asia.
Saha S1, Chadha M2, Al Mamun A3, Rahman M4, Sturm-Ramirez K3, Chittaganpitch M5, Pattamadilok S5, Olsen SJ6, Sampurno OD7, Setiawaty V7, Pangesti KN7, Samaan G8, Archkhawongs S9, Vongphrachanh P9, Phonekeo D9, Corwin A10, Touch S11, Buchy P12, Chea N13, Kitsutani P14, Mai le Q15, Thiem VD15, Lin R16, Low C16, Kheong CC17, Ismail N18, Yusof MA19, Tandoc A 3rd20, Roque V Jr21, Mishra A2, Moen AC22, Widdowson MA22, Partridge J23, Lal RB3.
Author information
Abstract
in English, Arabic, Chinese, French, Russian, Spanish
OBJECTIVE:
To characterize influenza seasonality and identify the best time of the year for vaccination against influenza in tropical and subtropical countries of southern and south-eastern Asia that lie north of the equator.
METHODS:
Weekly influenza surveillance data for 2006 to 2011 were obtained from Bangladesh, Cambodia, India, Indonesia, the Lao People's Democratic Republic, Malaysia, the Philippines, Singapore, Thailand and Viet Nam. Weekly rates of influenza activity were based on the percentage of all nasopharyngeal samples collected during the year that tested positive for influenza virus or viral nucleic acid on any given week. Monthly positivity rates were then calculated to define annual peaks of influenza activity in each country and across countries.
FINDINGS:
Influenza activity peaked between June/July and October in seven countries, three of which showed a second peak in December to February. Countries closer to the equator had year-round circulation without discrete peaks. Viral types and subtypes varied from year to year but not across countries in a given year. The cumulative proportion of specimens that tested positive from June to November was > 60% in Bangladesh, Cambodia, India, the Lao People's Democratic Republic, the Philippines, Thailand and Viet Nam. Thus, these tropical and subtropical countries exhibited earlier influenza activity peaks than temperate climate countries north of the equator.
CONCLUSION:
Most southern and south-eastern Asian countries lying north of the equator should consider vaccinating against influenza from April to June; countries near the equator without a distinct peak in influenza activity can base vaccination timing on local factors.
PMID:
24839321
[PubMed - in process]
http://www.ncbi.nlm.nih.gov/pubmed/24839321
Influenza seasonality and vaccination timing in tropical and subtropical areas of southern and south-eastern Asia.
Saha S1, Chadha M2, Al Mamun A3, Rahman M4, Sturm-Ramirez K3, Chittaganpitch M5, Pattamadilok S5, Olsen SJ6, Sampurno OD7, Setiawaty V7, Pangesti KN7, Samaan G8, Archkhawongs S9, Vongphrachanh P9, Phonekeo D9, Corwin A10, Touch S11, Buchy P12, Chea N13, Kitsutani P14, Mai le Q15, Thiem VD15, Lin R16, Low C16, Kheong CC17, Ismail N18, Yusof MA19, Tandoc A 3rd20, Roque V Jr21, Mishra A2, Moen AC22, Widdowson MA22, Partridge J23, Lal RB3.
Author information
Abstract
in English, Arabic, Chinese, French, Russian, Spanish
OBJECTIVE:
To characterize influenza seasonality and identify the best time of the year for vaccination against influenza in tropical and subtropical countries of southern and south-eastern Asia that lie north of the equator.
METHODS:
Weekly influenza surveillance data for 2006 to 2011 were obtained from Bangladesh, Cambodia, India, Indonesia, the Lao People's Democratic Republic, Malaysia, the Philippines, Singapore, Thailand and Viet Nam. Weekly rates of influenza activity were based on the percentage of all nasopharyngeal samples collected during the year that tested positive for influenza virus or viral nucleic acid on any given week. Monthly positivity rates were then calculated to define annual peaks of influenza activity in each country and across countries.
FINDINGS:
Influenza activity peaked between June/July and October in seven countries, three of which showed a second peak in December to February. Countries closer to the equator had year-round circulation without discrete peaks. Viral types and subtypes varied from year to year but not across countries in a given year. The cumulative proportion of specimens that tested positive from June to November was > 60% in Bangladesh, Cambodia, India, the Lao People's Democratic Republic, the Philippines, Thailand and Viet Nam. Thus, these tropical and subtropical countries exhibited earlier influenza activity peaks than temperate climate countries north of the equator.
CONCLUSION:
Most southern and south-eastern Asian countries lying north of the equator should consider vaccinating against influenza from April to June; countries near the equator without a distinct peak in influenza activity can base vaccination timing on local factors.
PMID:
24839321
[PubMed - in process]
http://www.ncbi.nlm.nih.gov/pubmed/24839321