CDC reports 96 new chikungunya cases, 584 total
The number of travel-related US chikungunya cases has grown to 580, an increase of 96 in the past week, the Centers for Disease Control and Prevention (CDC) said today in its weekly update. The number of locally acquired cases stayed at 4, for 584 total US cases.
Forty-two states and the District of Columbia have reported cases, two more states than a week ago. The locally acquired cases were all in Florida, which has confirmed 24% of all cases (138). The second-most affected state is New York, with 96 cases.
Travel to the Caribbean region, which has had at least 576,000 cases in an outbreak that began last December, accounts for 572 of the 580 cases, the CDC said. The rest of the patients picked up the virus in the Pacific (5 cases) or Asia (3).
From 2006 through 2013, the United States averaged only 28 reported chikungunya cases a year, the agency said.
The number of cases in Puerto Rico and the US Virgin Islands stayed the same, with Puerto Rico reporting 201 locally transmitted cases and 16 travel-related ones and the Virgin Islands reporting 2 cases in each category.
Aug 13 CDC update
Vietnam reports 2 outbreaks of new H5N6 avian flu strain in poultry
Outbreaks of a new strain of highly pathogenic avian flu—H5N6—have been reported in poultry in two areas of Vietnam, according to a report yesterday from the World Organization for Animal Health (OIE). The outbreaks occurred in April and June of this year, but testing to determine the specific strain of H5 delayed reporting.
The smaller, April outbreak occurred in Trang Dinh district, Lang Son province, in the far north of the country. It sickened 40 birds of an 80-bird flock; 15 died and the remaining 65 were destroyed.
The second outbreak, in June, caused clinical disease in 950 of a 1,900-bird flock in Ky Anh district of Ha Tinh province in the central part of the country. No poultry deaths from the disease were reported, but all in the flock were destroyed.
The report gives the apparent morbidity rate as 50%; no mortality or case-fatality rates are reported because of missing information, it says. "This is a new strain detected from outbreak surveillance activities," the OIE report says.
Control measures undertaken in addition to stamping out include movement control within the country, screening, and disinfection of the affected premises. Testing of poultry in surrounding flocks showed no infection.
Aug 12 OIE report
IV peramivir failed to hasten flu relief in randomized trial
The intravenous (IV) influenza drug peramivir, which was used on an emergency basis during the 2009 flu pandemic, did not significantly speed up the relief of symptoms in a randomized controlled trial, according to a report yesterday in Clinical Infectious Diseases.
Peramivir, a neuraminidase inhibitor made by BioCryst Pharmaceuticals, is intended for use in patients who can't take an oral or inhaled flu drug. It is not approved in the United States, but it is licensed in Japan, where it is marketed as Rapiacta, and in South Korea.
In the trial, patients who were hospitalized with suspected flu were randomly assigned to receive a 5-day course of treatment with IV peramivir (600 milligrams once daily) or a placebo. All the patients also all received the hospital's standard care for their illness.
Flu was confirmed in 338 of 405 enrolled patients, the report says. The subgroup used for the primary efficacy analysis consisted of 121 patients who did not receive another neuraminidase inhibitor as part of standard care.
For the peramivir group, the median time to resolution of symptoms was 42.5 hours (95% confidence interval [CI], 34.0-57.9), versus 49.5 hours (95% CI, 40.0-61.9) for the placebo group, a nonsignificant difference (P = .973).
The peramivir group showed greater reductions in viral shedding than the placebo group did, but this difference too was nonsignificant, the report states. Adverse events and lab abnormalities were similar in both groups.
Although peramivir was generally safe and well-tolerated, "the study was terminated for futility following a pre-planned interim analysis," the report says, adding, "This study highlights the challenges in designing studies to evaluate influenza antiviral agents in a hospitalized setting."
Aug 12 Clin Infect Dis abstract
Related Nov 9, 2012, CIDRAP News story
BioCryst information on peramivir
Flu activity rising in some Southern Hemisphere countries
Flu activity in the Southern Hemisphere continued to increase, especially in Australia and New Zealand, but also in South Africa and some parts of South America, the World Health Organization (WHO) said in an Aug 11 update.
The 2009 H1N1 virus is responsible for most of the activity in Australia and New Zealand, but the most commonly detected flu virus in South America and South Africa was H3N2.
In general, flulike illness activity in South America is at expected levels, but increases are occurring in some areas, such as Bolivia. The WHO said flu may have peaked in some parts of the region, such as Chile and Argentina. Some South American countries are also reporting brisk respiratory syncytial virus (RSV) activity.
The Southern Hemisphere's flu season typically runs from May through October.
In Africa and most parts of Asia, flu activity remained low, except for some activity occurring in southern China, where the H3N2 strain is dominant.
Globally, the most commonly detected flu strain is H3N2, followed by 2009 H1N1.
Aug 11 WHO flu update