H7N9 sampling study finds temporary benefits for market closures
Temporary poultry market closures can drop environmental levels of H7N9 and other avian flu viruses, but after stalls reopen, contamination quickly returns to preclosure levels, Chinese researchers reported yesterday in Emerging Infectious Diseases.
The study took place in Guangzhou, the largest city in southern China's Guangdong province, during the second wave of human illnesses.
In response to rising numbers of human infections in the city in the first months of 2014, officials ordered a 2-week closure of live-poultry markets from Feb 15 to Feb 28. The markets were cleaned and disinfected at the start of the closure, and the team collected environmental samples from different areas of the markets before, during, and after the closure. Samples were tested by real-time reverse transcription polymerase chain reaction (rT-PCR) and culture.
During the closure period, H7N9 RNA detections fell by 79% and isolation decreased by 92%. The investigators also found that viable virus could still be cultured from wastewater about 2 days after poultry market closure. Chopping boards, often located at the front of the stalls, had the highest contamination rates of any other sampling site in the markets.
Investigators found, however, that virus returned to preclosure levels when the markets opened again, a rebound that requires further investigation, they wrote. The group added that, given little support for permanent poultry market closures, health officials could consider more ways to minimize risks to humans, including putting a screen between customers and the chopping board or redesigning stalls to limit transmission to humans.
Sep 3 Emerg Infect Dis study
Variant H3N2 case reported in Michigan
Variant H3N2 influenza (H3N2v) has been detected in a Michigan resident who was hospitalized in June with an infection and has now recovered, the US Centers for Disease Control and Prevention (CDC) reported today in its weekly flu update.
An investigation into the case found no human-to-human spread of the virus, and the patient had close contact with pigs in the week before illness onset.
The case is the second involving H3N2v this year. On July 24 the CDC reported a case from Minnesota, which also involved a patient who had contact with swine the week before symptoms began. That patient was also hospitalized, and no other infections were detected in contacts.
The virus was first detected in humans in 2011 and spiked to 306 cases the following summer, much of them linked to swine exhibit exposure.Cases have declined rapidly since then, however, with sporadic detections of H3N2v as well as H1N1v.
Sep 4 CDC FluView
Jul 24 CIDRAP News scan "H3N2v case reported in Minnesota"
CDC study notes risk factors for MRSA after hospital discharge
Colonization of resistant bacteria and discharge to a nursing home are among the risk factors for developing methicillin-resistant Staphylococcus aureus (MRSA) after discharge after hospitalization for acute care, according to a study yesterday in Clinical Infectious Diseases.
A team led by CDC researchers analyzed data on 194 patients who developed MRSA after hospital discharge from Feb 1, 2011, to Mar 31, 2013, and 388 matched controls. The median time between discharge and positive MRSA culture was 23 days, with a range of 1 to 83 days.
They found these factors independently associated with post-discharge MRSA: MRSA colonization, discharge to a nursing home, presence of a chronic wound, and discharge with a central venous catheter (CVC) or a non-CVC invasive device.
The authors concluded, "Prevention efforts should target patients with MRSA colonization or those with invasive devices or chronic wounds at hospital discharge. In addition, MRSA prevention efforts in nursing homes are warranted."
Sep 3 Clin Infect Dis abstract