Jun 20, 2012
CDC says new test will speed detection of dengue cases
A new test developed by the Centers for Disease Control and Prevention (CDC) will speed the identification of dengue virus infections, improving surveillance and patient care, the CDC said in a press release today. The test, called the CDC DENV-1-4 Real Time RT PCR Assay, will help diagnose dengue within the first 7 days after symptoms appear, which is when most people are likely to seek treatment and the dengue virus is likely to be present in their blood, the agency said. The test, which has been approved by the Food and Drug Administration, can identify all four dengue virus types. The agency said the test is the first Food and Drug Administration–approved molecular assay that finds evidence of the virus itself. The other approved test detects an antibody to the virus, but it takes at least 4 days after illness onset for the antibody to appear, so cases can be missed. Jorge L. Munoz-Jordan, PhD, of the CDC's Dengue Branch said the need for the new test was high. "Patients will be diagnosed sooner than before, and public health laboratories will have a clearer picture of the true number of dengue cases," he said, adding that dengue is now a reportable disease in the United States. Officials said another advantage of the test is that it can be used with equipment that many public health labs already use to diagnose influenza. Test kits will be available Jul 2.
Jun 20 CDC press release
Study: Case definition, scoring system both fail at H1N1 diagnosis
Accurate clinical diagnosis of pandemic 2009 H1N1 flu (pH1N1) during the pandemic was difficult, and using a structured scoring system didn't help, Australian researchers concluded in a study yesterday in Influenza and Other Respiratory Viruses. The team assessed 818 patients who presented with influenza-like illness to three Melbourne hospitals and an affiliated clinic. All filled out a questionnaire on their symptoms, comorbidities, and risk factors. Of the 818 patients, 253 (31%) were tested after more than 3 days of symptoms, with 77 (30%) positive for pH1N1. The researchers then used logistic regression to test the accuracy of a case definition created by experts of the Communicable Diseases Network Australia and of a scoring system that used factors most strongly associated with outcome on multivariable analysis. Positive predictive values were low for both methods: 39% to 44% for the case definition and 38% to 58% or the scoring system. Negative predictive values were 83% to 84% and 73% to 94%, respectively. The authors recommend investing in rapid, sensitive diagnostic tests.
Jun 19 Influenza Other Respi Viruses abstract
Poll finds residents sometimes work while sick
In a small poll of resident physicians, more than half reported working while sick with flu-like symptoms, most commonly out of a sense of obligation to colleagues and patient care, according to a research letter published in the Archives of Internal Medicine. The anonymous survey of "presenteeism" targeted 150 residents who attended the 2010 annual meeting of the American College of Physicians' Illinois chapter. Participants were asked if they had worked while having flu-like symptoms in the preceding year and, if so, why. Seventy-seven respondents (51%) said they had worked while sick at least once, and 24 (16%) reported doing so at least three times. Fourteen (9%) residents acknowledged believing they had passed an illness to a patient. Second-year and female residents were more likely to report working sick than first-year and male residents, though the differences were not significant. Among those who worked when sick, the most common reasons were an obligation to colleagues (57%) and an obligation to patients (56%). "Resident presenteeism should be better identified and addressed by medical educators and residency leaders," the report says.
Jun 18 Arch Int Med research letter
Researchers find Google data correlate well with norovirus outbreaks
Tracking Google searches for gastroenteritis (GE)-related search terms correlated strongly with US national and regional norovirus surveillance data, a study in Clinical Infectious Diseases revealed. Researchers with the US Centers for Disease Control and Prevention (CDC) and Google Labs in Tel Aviv, Israel, analyzed monthly Google Internet query share (IQS) data from 30 states as well the entire US population from Jan 1, 2004, through Apr 30, 2010. They also collected weekly IQS data for the Boston metro area. They focused the search on GE-related terms. They correlated those data with norovirus outbreak surveillance data from the same 30 states and nationally (norovirus is the most common cause of GE in the country), as well as data on emergency department visits for GE in the Boston area. They found strong correlations at the national (R2 = 0.70), regional (R2 = 0.74), and local (R2 = 0.74) levels. The authors conclude, "IQS data may facilitate rapid identification of norovirus season onset, elevated peak activity, and potential emergence of novel strains."
Jun 19 Clin Infect Dis abstract