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Swine Flu Update: WHO Raises Pandemic Alert Level • EU Issues Travel Advisories for United States and Mexico • Additional Cases in NYC and Other Countries • Updated Guidance from CDC

By the Staff of the Center for Biosecurity | April 27, 2009 | 7:40 PM, EST

Today, the Director General (DG) of the World Health Organization (WHO) raised the influenza pandemic alert level from the current phase 3 to phase 4.1

This decision follows from advice given by the WHO’s Emergency Committee, which met this morning to consider "available data on confirmed outbreaks of A/H1N1 swine influenza in the United States of America, Mexico, and Canada . . . [and] reports of possible spread to additional countries.”

Based on the advice of the Committee:

  • The DG recommended that nations focus on measures to mitigate the spread of infection.

  • In light of widespread presence of the virus, the WHO has deemed that “containment of the outbreak is not feasible.”

  • The DG recommended against closing borders or restricting international travel. The WHO noted that it is “prudent for people who are ill to delay international travel and for people developing symptoms following international travel to seek medical attention.”

  • The DG said that “production of seasonal influenza vaccine should continue at this time, subject to re-evaluation as the situation evolves.”

EU Issues Travel Advisories for the United States and Mexico

On Monday, April 27, European Union (EU) Health Commissioner Androulla Vassiliou issued a travel advisory to the 27 EU member countries recommending that “non-essential” travel to affected parts of the U.S. and Mexico be suspended.2 According to Vassiliou, this is a travel advisory only and not a travel ban, and it is up to member countries to make their own determinations about whether to set travel and trade restrictions. The acting Director of the Centers for Disease Control and Prevention (CDC), Richard Besser, responded by commenting that EU travel recommendation is not warranted: "At this point I would not put a travel restriction or recommendation against coming to the United States,” said Besser.

Epidemiology Update: Additional Cases in NYC and Other Countries

In the U.S., a total of 40 cases have been confirmed. Today’s increase in case number comes after 20 additional cases were confirmed in New York City at the St. Francis Preparatory School. All U.S. cases continue to report only mild illness.3

Several updates have occurred since yesterday in the worldwide reports of suspected cases of swine flu:

  • New Zealand is now reporting 25 cases under suspicion.4

  • Spain has confirmed 1 of its 6 suspected cases.5

  • Australia’s 2 suspected cases have tested negative.6

  • France’s 4 suspected cases have tested negative.7

  • Italy has 1 case under suspicion.7

  • England has also ruled out swine flu in 1 suspected case.7

  • Scotland has confirmed 2 cases.2

  • Columbia has 12 suspected cases.4

  • Brazil has 1 suspected case.4

The European CDC states that among France, England, and Scotland, 12 cases are suspected, but enumeration is not provided.

Updated Guidance Documents from Centers for Disease Control and Prevention (CDC)

Yesterday, the CDC issued guidance for controlling the spread of swine flu in communities: Interim CDC Guidance for Nonpharmaceutical Community Mitigation in Response to Human Infections with Swine Influenza (H1N1) Virus. This document updates CDC’s Community Strategy for Pandemic Influenza Mitigation, which was issued in 2007.

Previous (2007) community mitigation guidance is based on an assessment of severity of illness in a given community. At this time, however, it is not possible to calculate the severity of the swine flu outbreak given currently available data. 

The CDC has issued additional swine flu guidance documents as well.


  1. World Health Organization. Statement by WHO Director-General Dr. Margaret Chan—Swine influenza. April 27, 2009. Accessed April 27, 2009

  2. Wools D. Swine flu prompts EU warning on travel to US. Associated Press. April 27, 2009. Accessed April 27, 2009.

  3. Investigation of New York City swine flu cluster continues; symptoms remain mild [news release]. New York, New York; New York City Department of Health and Mental Hygiene. April 27, 2009. Accessed April 27, 2009.

  4. European Centre for Disease Prevention and Control. Swine influenza (H1N1). April 27, 2009.
    . Accessed April 27, 2009.

  5. WHO raises pandemic alert level; more swine flu cases feared. CNN. April 27, 2009. Accessed April 27, 2009.

  6. Officials unleash drug arsenal as flu toll rises. Agence France Press. April 27, 2009.
    . Accessed April 27, 2009.

  7. Italy finds first suspected swine flu case. April 27, 2009. Accessed April 27, 2009.