This report provides an update to the international situation as of May 21, 2010. The World Health Organization (WHO) continues to report updated 2009 H1N1 flu-associated laboratory-confirmed cases and deaths on its Web page.

During week 19 ( May 9 - 15, 2010), influenza activity decreased in the U.S. 14 (0.9%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories and reported to CDC/Influenza Division were positive for influenza.

This document provides guidance to help prevent and control the spread of influenza (flu), including 2009 H1N1 flu, among campers and camp staff during the 2010 summer camp season. This guidance updates the earlier camp guidance on "novel influenza A (H1N1 flu) virus" that was issued on June 14, 2009.

During week 18 ( May 2 - 8, 2010), influenza activity decreased in the U.S.26 (1.5%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories and reported to CDC/Influenza Division were positive for influenza.

This report provides an update to the international situation as of May 14, 2010. The World Health Organization (WHO) continues to report updated 2009 H1N1 flu-associated laboratory-confirmed cases and deaths on its Web page.

CDC is updating the Interim Guidance on Infection Control Measures for 2009 H1N1 Influenza in Healthcare Settings, Including Protection of Healthcare Personnel. Circumstances have changed significantly with respect to availability of a safe and effective vaccine, and in terms of what we know about the health impact of the novel H1N1 influenza strain. The guidance is being updated to reflect newer information.

During week 16 (April 18-24, 2010), influenza activity decreased in the U.S.16 (1.2%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories and reported to CDC/Influenza Division were positive for influenza.

This report provides an update to the international situation as of April 23, 2010. The World Health Organization (WHO) continues to report updated 2009 H1N1 flu-associated laboratory-confirmed cases and deaths on its Web page.

During week 15 (April 11-17, 2010), influenza activity decreased in the U.S. 37 (2.1%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories and reported to CDC/Influenza Division were positive for influenza.

This document provides updated information on pregnancy as a risk factor for serious 2009 H1N1-related complications based on findings from a recent study.

CDC has again updated its estimates of the total number of 2009 H1N1 cases, hospitalizations and deaths in the United States since April, 2009. The new estimates incorporate an additional four weeks of flu data from the previous estimates released on March 12, 2010.

This report provides an update to the international situation as of April 16, 2010. The World Health Organization (WHO) continues to report updated 2009 H1N1 flu-associated laboratory-confirmed cases and deaths on its Web page.

As of April 16, 2010, the Aggregate Hospitalizations and Deaths Reporting Activity (AHDRA) has concluded for the 2009-2010 flu season. The AHDRA surveillance system was created specifically in response to the 2009 H1N1 pandemic, and the system will be maintained for quick implementation in the event of another flu pandemic. CDC will continue to track hospitalizations and deaths through its traditional seasonal flu surveillance systems during the 2010-2011 season. Pneumonia and influenza-related deaths in adults and children will be tracked through the 122 Cities Mortality Reporting System. Laboratory confirmed, flu-related deaths in children will continue to be tracked through the Influenza-associated Pediatric Mortality Surveillance system. Laboratory confirmed, flu-related hospitalizations in adults and children will be tracked through the Emerging Infections Program (EIP).

Morbidity and Mortality Weekly Report (MMWR) April 16, 2010 / 59(14);423-430

This report provides an update to the international situation as of April 9, 2010. The World Health Organization (WHO) continues to report updated 2009 H1N1 flu-associated laboratory-confirmed cases and deaths on its Web page.

During week 13 (March 28-April 3, 2010), influenza activity decreased slightly in the U.S. 105 (3.7%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories and reported to CDC/Influenza Division were positive for influenza.

Flu activity in the United States declined slightly from last week and is low nationally; however, some states in the Southeast continue to report regional activity, according to the March 28-April 3, 2010 FluView. Most flu continues to be 2009 H1N1. Flu activity, caused by either 2009 H1N1 or seasonal flu viruses, may rise and fall, but is expected to continue for weeks in the U.S. Internationally, 2009 H1N1 flu is still circulating, including in the Southern Hemisphere, which is about to enter its flu season. For more information, please see the international situation update.

If you provide care for a person with a disability either at home or in a community-based setting, read the 5 Things Caregivers of People with Disabilities Need to Know about the Flu

If you are a person with a disability, read the 5 Things People with Disabilities Need to know about the Flu.

Morbidity and Mortality Weekly Report (MMWR) April 2, 2010 / 59(12); 363-368