May 20, 2011
Analysis of 2007 H5N1 cases in Pakistan shows additional likely, possible cases
A look back at an H5N1 avian flu outbreak involving human-to-human transmission in Pakistan in 2007 found that, for every confirmed case, as many as four additional people may have been infected. Researchers examined records from all hospitals that treated patients who had suspected H5N1 influenza in the country's remote Northwest Frontier Province in late 2007. Using World Health Organization (WHO) criteria "slightly modified" for clinicians in resource-poor settings, they identified 4 confirmed, 7 likely, and 9 possible H5N1 cases. Of these 20, 8 (including the 4 confirmed cases) were listed as a cluster involving human-to-human transmission. The other 12 cases were not epidemiologically linked to the cluster. One of the 4 confirmed cases was asymptomatic. Of note, the WHO lists only 3 of these cases as confirmed. It appears the agency does not include the asymptomatic case in its global case count, which shows that this 2007 outbreak involved the only instance of confirmed human H5N1 cases in Pakistan.
May 19 Emerg Infect Dis report
Zombie mob crashes CDC preparedness blog
A lighthearted blog post on emergency planning featuring a zombie attack, designed by the US Centers for Disease Control and Prevention (CDC) to pitch the preparedness message to a younger, social-media-savvy audience , was so popular that it crashed some of the CDC's Web servers 2 days after it was posted, Reuters reported. The CDC's Dave Daigle, spokesman for its Office of Public Health Preparedness and Response, told Reuters that a typical CDC blog post averages between 1,000 and 3,000 hits, and that the previous top blog post had netted about 10,000 hits. However, he said by the end of May 18 when the servers crashed the zombie post had received about 60,000 hits. The blog post by Ali Kahn, MD, MPH, who leads the CDC's office of public health preparedness and response, uses a zombie apocalypse as an example of a public health disaster and leads readers through preparedness steps that can be used in other settings such as hurricanes or influenza pandemics. In popular movies and books, infectious diseases or exposure to radiation or chemical attacks reanimate dead people—zombies—who feed on other humans, especially their brains.
May 19 Reuters story
May 16 CDC blog post
Pandemic H1N1 depletes dendritic cells for weeks
Infection with pandemic 2009 H1N1 depletes the body of dendritic cells for weeks, according to a study published yesterday. Dendritic cells are immune cells that process antigen material and present it on the surface of other immune cells. Italian researchers collected blood samples from 13 patients hospitalized with pandemic 2009 H1N1–related pneumonia at admission and 1, 4, and 16 weeks later. In the acute phase of the disease, H1N1-infected patients had a significant depletion in both circulating myeloid and plasmacytoid dendritic cells. In addition, the number of plasmacytoid dendritic cells in the H1N1 patients remained lower than in healthy controls even after 16 weeks.
May 19 PLoS One study
Google search patterns can predict MRSA hospitalizations
Researchers have successfully used Google search patterns to conduct flu surveillance, and a new study suggests the same method could work for identifying trends in methicillin-resistant Staphylococcus aureus (MRSA) hospitalizations. The study, from researchers at the University of Colorado, Boulder, and the University of Chicago, was published yesterday in Emerging Infectious Diseases. Currently, there is no surveillance system for MRSA. First they used the Google Trends database to obtain information on all Google searches that contained the words "MRSA" or "staph." Then they used a quarterly hospital discharge database to calculate the proportion of hospitalizations that involved a diagnosis of MRSA. They found that news coverage didn't affect the relationship between search queries and hospitalizations, but they did find an association between Internet search activity and hospital discharge data: increasing incidence from 2004 to 2007, with signs of seasonal variation and no increase in 2008. They concluded that Internet surveillance of MRSA traffic could be useful, because there is no true standard for MRSA incidence.
May 19 Emerg Infect Dis abstract