News

1. WHO-EURO – Situation update in the European Region: overview of influenza surveillance data week 40/2009 to week 07/2010

On 11 March 2010, the World Health Organization, Regional Office for Europe (WHO-EURO) announced the publication on its website of the latest overview of the EuroFlu data. This information is accessible at http://www.euro.who.int/influenza/AH1N1/20100309_1. It has been published in English but a Russian translation will be available shortly, the organization announced.

2. WHO Guidelines for Pharmacological Management of Pandemic (H1N1) 2009 Influenza and other Influenza Viruses

On 10 March 2010 the World Health Organization (WHO) published a revision of its antiviral guidelines, formally titled ‘WHO Guidelines for Pharmacological Management of Pandemic (H1N1) 2009 Influenza and other Influenza Viruses’, that replaces the previous set published back in August 2009.
Key changes to the guidelines are:

• Simplification of recommendations as pandemic influenza virus has become the predominant influenza virus worldwide;
• Specific guidance for the treatment of young children from birth, including guidance on dose and formulation;
• Additional guidance for treatment or chemoprophylaxis of patients with severe immunosuppression;
• Consideration of a wider range of investigational, regional or adjunctive treatments;
• Specific contraindications for some medicines.

These guidelines consist of two parts, one containing recommendations and one including the review of evidence.

Click below to read the guidelines: http://www.who.int/csr/resources/publications/swineflu/h1n1_use_antivirals_20090820/en/index.html

3. WHO Weekly situation update on the 2009 Influenza A(H1N1) Pandemic

The latest situation update from WHO with regards to the 2009 influenza  A(H1N1) Pandemic was released on the 5 March 2010 and can be found in this link:  http://www.who.int/csr/disease/swineflu/updates/en/index.html

In brief, WHO reports that outside of Europe the most active areas of pandemic transmission are currently observed in parts of Southeast Asia; influenza type B is increasingly reported in Asia. Respiratory tract infections in the north western area of Pakistan and Afghanistan are reportedly increasing. Whether this increased activity is due to circulation of influenza is not known. In Sub-Saharan Africa, several West African countries are increasingly reporting pandemic influenza cases, though surveillance data from the area is quite limited. Data from the rest of Africa suggests that influenza activity in most countries is low and transmission continues to be sporadic.

4. FDA Issues Final Guidance to Boost Development of Cell-based Viral Vaccines

The U.S. Food and Drug Administration this week issued final guidance to help manufacturers who are developing safe and effective cell-based viral vaccines to address emerging and pandemic threats. This document, titled ‘Guidance for Industry: Characterization and Qualification of Cell Substrates and Other Biological Materials Used in the Production of Viral Vaccines for Infectious Disease Indications,’ will aid manufacturers who wish to use new cell substrates for vaccine production, such as for influenza vaccines. In addition, it outlines the best practices using current and emerging science to safely expand the types of cells that may be used to produce vaccines.

Selected Scientific Publications

EPIDEMIOLOGY

Epidemiology of patients with severe symptoms of 2009 pandemic influenza A(H1N1):
Pandemic 2009 Influenza A(H1N1) in Argentina: A Study of 337 Patients on Mechanical Ventilation
Estenssoro E, Ríos FG, Apezteguía C, et al.
Am J Respir Crit Care Med. 2010 Mar 4. [Epub ahead of print]

This is a description of the severity of the disease in patients with confirmed, probable and suspected viral pneumonia caused by 2009 pandemic influenza A(H1N1) admitted to 35 intensive care units with acute respiratory failure requiring mechanical ventilation in Argentina, between June 3 and September 7, 2009. This  is a cohort study including 337 consecutive adult patients. Data were collected in a form posted on the website of the ‘Argentinian Society of Intensive Care’. Patients with 2009 pandemic influenza A(H1N1) infection requiring mechanical ventilation were mostly middle-aged adults, often with co-morbidities, and frequently developed severe ARDS and multi-organ failure requiring advanced organ support. Case-fatality rate was accordingly high.

VIROLOGY

Pre-pandemic oseltamivir resistance and clinical effectiveness of oseltamivir and zanamivir:
A two-year survey of the oseltamivir-resistant influenza A(H1N1) virus in Yamagata, Japan and the clinical effectiveness of oseltamivir and zanamivir
Matsuzaki Y, Mizuta K, Aoki Y, et al.
Virol Journal 2010 Mar 5;7(1):53

The aim of this study was to determine the rate of oseltamivir resistance among influenza A(H1N1) virus isolates from Yamagata, Japan, to compare the virological characteristics between isolates from the 2007-2008 and 2008-2009 seasons, and to evaluate the clinical effectiveness of oseltamivir.  Oseltamivir resistance, determined by detecting the H275Y mutation in the neuraminidase (NA) gene, was observed in 2.5% (2 of 79) and 100% (77 of 77) of isolates from the 2007-2008 and 2008-2009 seasons, respectively. A phylogenetic analysis revealed that two oseltamivir-resistant viruses isolated in the 2007-2008 season were closely related to other oseltamivir-susceptible viruses in Yamagata but were different from oseltamivir-resistant viruses isolated in Europe and North America in the 2007-2008 season.  In conclusion, oseltamivir-resistant A(H1N1) isolates from Yamagata in the 2007-2008 season might have acquired resistance through the use of oseltamivir, and the 2008-2009 oseltamivir-resistant isolates might have been introduced into Japan and circulated throughout the country.

PUBLIC HEALTH POLICY

Estimated impact of school closures in Hong Kong, China during pandemic 2009:
School closure and mitigation of pandemic (H1N1) 2009, Hong Kong
Wu JT, Cowling BJ, Lau EHY, Ip DKM, Ho L-M, Tsang T, et al.
Emerg Infect Dis [serial on the Internet]; 2010 March [date cited]

In Hong Kong, kindergartens and primary schools were closed as soon as local transmission of 2009 pandemic influenza A(H1N1) was identified in June. In contrast, secondary schools remained open until the traditional holidays starting in July. The authors used data from case and laboratory reporting and a simple age-structured susceptible-infectious-recovered transmission model to interpret age-specific reporting data. The three age classes were less than 13 years, 13 to 19 years and more than 19 years. The authors noted that children <13 years of age seemed to be relatively unaffected in Hong Kong during the school closure period and that this implied that primary school and kindergartn closures were effective in preventing infections in the younger age groups. Furthermore, assuming that children are responsible for up to half of all community transmission the authors concluded that protection of younger children had substantial indirect benefits. They found that the estimated reproductive number declined from 1.5 during the kindergarten and primary school closures to 1.1 during the summer vacation suggesting that an even greater drop in attack rates would result from sustained school closures. The closure of secondary schools for the summer vacation was associated with substantially lower transmission across age groups a decline in the estimated observed reproductive number of 1.5 during the kindergarten and primary school closures to 1.1 during the period when all schools were closed. The authors conclude that in this pandemic a much more substantial drop in attack rates would result from sustained school closures.