Study: Test can determine whether respiratory infection is viral or bacterial
A team led by Duke University researchers has developed a gene-detecting test that could help physicians determine whether an acute respiratory infection (ARI) is caused by a virus or a bacterium, which could reduce antibiotic overprescribing, according to a study yesterday in Science Translational Medicine.
The investigators used host gene expression classifiers—or gene signatures—which reflect which of a patient's genes are turned on or off, to indicate whether the person's body is combatting an infection from a virus, bacterium, or both. They analyzed blood samples from 273 people with ARI or a noninfectious illness, as well as 44 healthy controls using their testing technique.
They found that the overall accuracy of the test was 87%, which was more accurate than a procalcitonin test (78%) and three published tests, which reported 78% to 83% accuracy.
"We use a lot of information to make a diagnosis, but there's not an efficient or highly accurate way to determine whether the infection is bacterial or viral," said lead author Ephraim L. Tsalik, MD, PhD, assistant professor of medicine at Duke, in a university press release. "There are risks to excess antibiotic use, both to the patient and to public health."
In US outpatient settings, about 73% of patients with respiratory illness caused by viral infection are mistakenly prescribed antibiotics, according to information provided to journalists by the American Association for the Advancement of Science, which publishes the journal.
"The ideal scenario, should this test ultimately be approved for broad use, is you would go to the doctor's office and receive your results by the time you meet with your provider," said senior author Christopher W. Woods, MD, professor of medicine and associate director of Duke's genomics center. "We are working to develop a test that could be run in most clinical labs on existing equipment."
Jan 20 Sci Transl Med study
Jan 20 Duke University press release
Report notes high-risk region in Hawaii's dengue outbreak
With the number of dengue fever cases on the Big Island of Hawaii now surpassing 200, researchers from the Hawaii Department of Health (HDOH) today detailed 107 cases from last fall, when the outbreak began, noting a high-risk region south of Kona, according to their report in Morbidity and Mortality Weekly Report (MMWR).
Via two medical advisories and a call for cases on Epi-X, the secure epidemic information exchange sponsored by the US Centers for Disease Control and Prevention, HDOH was able to identify 107 lab-confirmed dengue cases on the Big Island with illness-onset dates ranging from Sep 11 to Nov 18, 2015.
Of those patients, 15 (14%) were hospitalized, but none died. Sixty-two (58%) were female, and patients' median age was 29 years, with a range of 0 to 80 years. Exposure information suggested at least one area of concern for contracting the mosquito-borne disease south of Kona, but patients recalled mosquito bites in other parts of the island, as well. At least 12 patients were never in an area south of Kona during their likely period of infection, 3 to 10 days before symptom onset.
"Staff persons from HDOH Vector Control are conducting assessments across Hawaii Island to identify possible areas of mosquito activity, and public outreach and education on mosquito avoidance and reduction are ongoing," the authors wrote.
The outbreak now totals 224 cases, according to an HDOH update yesterday. The agency considers all of the patients to be no longer contagious, as their illnesses began from Sep 11, 2015, to Jan 8. Of the confirmed cases, 22 are visitors to Hawaii and 202 are residents. The update notes several areas on the island where risk is increased, including the high-risk zone noted in the MMWR report.
Jan 22 MMWR report
Jan 20 HDOH update
Cote d'Ivoire, India report H5N1 outbreaks in poultry
Cote d'Ivoire on Jan 19 reported 12 outbreaks of H5N1 avian flu in chickens that happened last year, while yesterday India reported the virus on a state-owned poultry farm, veterinary officials noted in separate reports to the World Organization for Animal Health (OIE).
The Cote d'Ivoire outbreaks involve flocks ranging from 160 to 1,500 birds. Eleven of the outbreaks began in July and August 2015, while the other started in November. They were all clustered in the southern city of Abidjan, which is on the Atlantic coast.
In total 119 birds became sick with the virus and 85 died out of 7,660 chickens. Of the remaining birds, only 111 were destroyed or slaughtered. Typically, response efforts to outbreaks of highly pathogenic avian flu involve euthanizing all surviving poultry to prevent the disease from spreading.
The outbreak in India began on Jan 9 in Tripura state, which is in the country's farthest eastern reach and sits to the east of Bangladesh. On a farm of 11,348 poultry, 1,760 were killed by the H5N1 virus and 5,263 others were culled.
Jan 19 OIE report on Cote d'Ivoire
Jan 20 OIE report on India