Your Health – CDC Updates and Awareness
CDC Updates – Jump to:
- Influenza Activity Dec 2013
- Salmonella Heidelberg
- Serogroup B Meningococcal Disease Outbreak at UCSB
- Learn about Communicable Illness and Pandemic Planning – Not if, but when
FROM THE CDC
Avian Influenza A (H7N9) Virus
Human infections with a new avian influenza A (H7N9) virus were first reported in China in March 2013. Most of these infections are believed to result from exposure to infected poultry or contaminated environments, as H7N9 viruses have also been found in poultry in China. While some mild illnesses in human H7N9 cases have been seen, most patients have had severe respiratory illness, with about one-third resulting in death. No evidence of sustained person-to-person spread of H7N9 has been found, though some evidence points to limited person-to-person spread in rare circumstances. No cases of H7N9 outside of China have been reported. The new H7N9 virus has not been detected in people or birds in the United States.
It’s likely that sporadic cases of H7N9 associated with poultry exposure will continue to occur in China. Cases associated with poultry exposure also may be detected in neighboring countries. It’s also possible that H7N9 may be detected in the United States at some point, possibly in a traveler returning from an affected area. Most concerning about this situation is the pandemic potential of this virus. Influenza viruses constantly change and it’s possible that this virus could gain the ability to spread easily and sustainably among people, triggering a global outbreak of disease (pandemic). CDC is following this situation closely and coordinating with domestic and international partners. CDC takes routine preparedness actions whenever a new virus with pandemic potential is identified, including developing a candidate vaccine virus to make a vaccine in case vaccine is needed. Those preparedness measures continue. CDC also has issued guidance to clinicians and public health authorities in the United States, as well as provided information for people traveling to China. CDC will provide updated information as it becomes available.
During the spring of 2013, the World Health Organization (WHO) reported 132 human H7N9 infections, with 44 deaths. Most cases had illness onset during the month of April. Beginning in May, new reports of human H7N9 infection in China became less frequent. From June to the end of September 2013, WHO reported three new H7N9 infections in China; one had illness onset in April, and one resulted in death. The decrease in H7N9 cases over the summer likely resulted from a combination of control measures taken by Chinese authorities – like closing live bird markets – and the change in weather. Studies indicate that avian influenza viruses, like seasonal influenza viruses, have a seasonal pattern: they circulate at higher levels in cold weather and at lower levels in warm weather.
More recently, the frequency of reports of human infection with H7N9 has increased; since the beginning of October, WHO and China have reported more new H7N9 cases in China per month relative to the summer months, including two cases reported by Hong Kong Special Administrative Region of People’s Republic of China in early December. These recent cases coincide with the arrival of cooler weather in China and are not unexpected. Some of the cases reported had poultry exposure and lived in areas where H7N9 had been found previously. Although epidemiological investigations are ongoing for some of the more recent cases, currently no evidence has been found that indicates sustained human-to-human transmission is occurring.
During September 29–December 7, 2013, approximately 140 World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System collaborating laboratories in the United States tested 61,261 respiratory specimens for influenza viruses; 4,183 (6.8%) were positive (Go to CDC Figure 1). Of these, 3,819 (91.3%) were influenza A viruses, and 364 (8.7%) were influenza B viruses. Of the 3,819 influenza A viruses, 1,998 (52.3%) were subtyped; 198 (10%) of these were influenza A (H3) viruses, and 1,800 (90%) were influenza A (H1N1)pdm09 (pH1N1) viruses. Since September 29, 2013, influenza-positive tests have been reported from 48 states, the District of Columbia, and Puerto Rico, representing all 10 U.S. Department of Health and Human Services (HHS) regions.§ Thus far, influenza A viruses have predominated nationally and in all 10 HHS regions. Read the Full Report
The University of California, Santa Barbara (UCSB) is experiencing an outbreak of serogroup B meningococcal disease, with four confirmed cases reported during November 2013. The Santa Barbara County Public Health Department (SBCPHD), the California Department of Public Health (CDPH), UCSB officials, and the Centers for Disease Control and Prevention (CDC) have been working closely together to monitor and respond to this outbreak and determine the best course of action to protect students’ health.
CDC is working under the assumption that the vaccine will be needed at UCSB, and taking steps to make it available if that is the case. However, most outbreaks of serogroup B meningococcal disease stop at 3 or 4 cases. Although we cannot predict how the UCSB outbreak will develop over the coming weeks and months, we are hopeful that the outbreak has concluded.