FDA expands outreach over produce safety rule
The US Food and Drug Administration (FDA) is reaching out to small- and medium-sized produce growers to address their questions about a proposed food safety rule issued in January, the agency said in a news release yesterday.
The proposed rule is aimed at preventing produce contamination in four areas—water, worker hygiene, materials put in soil, and animal presence among crops—as well as addressing conditions in packing houses. The FDA has received considerable feedback on parts of the rule, such as proposed water standards, which some growers view as too onerous.
"Engagement with stakeholders has been, and will continue to be, a priority for FDA, and the Agency is planning additional outreach, including targeted outreach on specific areas such as agricultural water that continue to generate questions," the agency said in the release.
As part of its outreach efforts, the FDA has made available a new interview with Michael Taylor, deputy commissioner for foods and veterinary medicine, and fact sheets on water standards, alternatives and variances to the rule, and produce that has been involved in disease outbreaks.
Comments on the proposed rule are due by Sep 16 and can be submitted on regulations.gov.
Jul 15 FDA news release
Jan 4 CIDRAP News story on release of produce rule
Study: T-705 looks like possible treatment for hantavirus infections
Studies in lab cultures and hamsters suggest that the broad-spectrum antiviral drug T-705 (favipiravir) may be a promising treatment for hantavirus pulmonary syndrome (HPS), a US-Japanese team of researchers reported yesterday in Antimicrobial Agents and Chemotherapy.
HPS, caused by rodent-borne hantaviruses, has a fatality rate of 30% to 50%. The researchers tested the drug against Andes virus and Sin Nombre virus (SNV), the predominant causes of HPS in South America and North America, respectively.
In cell culture testing, T-705 "potently inhibited" both viruses as evidenced by decreased detection of viral RNA and lower infectious titers, the report says.
The team ran several experiments in hamsters. In one of them, six groups of hamsters were dosed with Andes virus and then treated twice daily for 14 days with various doses of T-705, starting 1 day after infection. In another, treatment was delayed until 3, 4, 5, or 6 days after infection.
The researchers found that daily treatment at 50 or 100 milligrams per kilogram reduced the detection of viral RNA and antigen in tissue specimens and significantly improved survival rates. With delayed treatment, the drug was protective against HPS if treatment began before the onset of viremia.
There is no animal model for SNV infection, but the team tested T-705 in hamsters infected with a hamster-adapted strain of the virus. They reported that daily treatment significantly reduced the detection of SNV RNA and antigen in tissue specimens, "suggesting the compound would also be effective against HPS in North America."
Together, "these results suggest T-705 treatment is beneficial for post-exposure prophylaxis against HPS-causing viruses and should be considered for probable exposures," they conclude.
Jul 14 Antimicrob Agents Chemother abstract
Increase in Powassan encephalitis may be linked to deer tick virus
A 5-year study of black-legged ticks in the New York's Hudson River Valley supports the idea that an increase in Powassan encephalitis cases in recent years is linked to increases in deer tick virus (DTC), a strain of Powassan virus, according to a report yesterday in Parasites & Vectors.
Although rare, Powassan encephalitis cases have increased over the past 15 years, possibly because of the emergence of DTV, also known as lineage II Powassan virus, especially in the Hudson Valley, the report says. The disease has a case-fatality rate of 10% to 15%, says a press release from the Cary Institute of Ecosystem Studies in Millbrook, N.Y., which was involved in the research.
In the study, more than 13,500 ticks were collected and tested for DTV from 2007 to 2012. Nearly all of them were black-legged ticks, or Ixodes scapularis, which also carry Lyme disease bacteria.
Fifty-eight tick pools were positive for DTV or its RNA, the report says. Infection rates were higher in adult ticks collected east of the Hudson River, with estimates ranging from 0.2 to 6.0 infected ticks per 100 where DTV was present. Infected ticks were found on Virginia opossums, striped skunks, and raccoons.
"High infection rates were detected in counties where recent [Powassan] encephalitis cases have been identified, supporting the hypothesis that lineage II [Powassan virus], DTV, is responsible for these human infections," the report says.
The press release says that DTV transmission can occur in just 15 minutes—far faster than other tick-borne infections such as Lyme disease, anaplasmosis, and babesiosis—which leaves little time for removing ticks.
Jul 15 Parasit Vectors report
Jul 15 Cary Institute press release
