Flu Scan for Oct 05, 2015

News brief

Flu vaccine tied to lower rates of flu-related pneumonia

The seasonal flu vaccine might cut the risk of contracting flu-associated pneumonia acquired in the community by more than half, a study today in the Journal of the American Medical Association (JAMA) found.

A team of US researchers, including some from the Centers for Disease Control and Prevention, analyzed data on patients ages 6 months and older from the Etiology of Pneumonia in the Community (EPIC) study, which was a prospective observational multicenter study of hospitalizations for community-acquired pneumonia conducted from January 2010 through June 2012 at four US sites.

They noted that 2,767 patients hospitalized for pneumonia were eligible for the study, of which 162 (5.9%) had lab-confirmed influenza. They found that 28 of 162 cases (17%) with flu-associated pneumonia and 766 of 2,605 controls (29%) with pneumonia but not flu had received flu vaccination.

The adjusted odds ratio of prior influenza vaccination between cases and controls was 0.43 (95% confidence interval [CI], 0.28-0.68), for an estimated vaccine effectiveness against flu-related pneumonia of 56.7% (95% CI, 31.9%-72.5%).
Oct 5 JAMA study
Oct 5 JAMA press release

Avian flu in Taiwan, Vietnam affects more than 10,000 poultry

Four outbreaks of H5N2 avian flu have hit poultry in Taiwan, while Vietnam reports a new H5N6 event, the latest in a string of outbreaks related to that strain, according to separate reports posted by the World Organization for Animal Health (OIE) late last week.

The Taiwanese outbreaks affected four poultry holdings totaling 10,062 birds, official reported in an Oct 2 OIE report. After 515 birds became sick and 455 died, H5N2 was confirmed in the flocks and the surviving poultry were euthanized to prevent further disease spread.

The affected premises were a 20-chicken flock on a farm in Changhua County, a 1,555-goose flock in Yunlin County, and duck farms of 1,784 and 6,703 birds in Yunlin County. The chicken outbreak began Aug 28, and the other three started in early September. The ducks tested positive as a result of enhanced surveillance after the goose outbreak was confirmed.

Taiwan has battled a host of avian flu outbreaks this year caused by the H5N2 and H5N8 strains, most recently about a month ago. Yunlin has been one of the hardest-hit counties.
Oct 2 OIE report on Taiwan

In Vietnam, the fairly new H5N6 variant killed 800 of 1,800 birds in a backyard flock in Lao Cai province in the extreme north, near the country's border with China. The remaining 1,000 poultry were destroyed.

The outbreak began on Oct 1, and response measures such as disinfection and enhanced surveillance have been implemented, according to an Oct 3 OIE report. Vietnam reported in August 2014 that the H5N6 strain affecting poultry in the country is novel.
Oct 3 OIE report on Vietnam

News Scan for Oct 05, 2015

News brief

WHO committee continues Ebola emergency, temporary measures

An emergency committee established to advise the World Health Organization (WHO) on Ebola outbreak response steps met for the seventh time last week and today announced that ongoing transmission and other factors still meet the threshold for a public health emergency of international concern (PHEIC) as defined by the International Health Regulations. The panel also said temporary measures to control the disease should remain in place.

The committee met by teleconference on Oct 1 and electronically on Oct 2 and 3, hearing from representatives from all three West African outbreak countries. Since the group's last meeting in early July Liberia has been declared free of Ebola for the second time, and the number of weekly cases reported from Guinea and Sierra Leone has stayed below 10.

Though each country has taken enhanced control steps, two active transmission chains—one in Guinea and one in Sierra Leone—continue to spark sporadic cases. The committee also noted that some cases aren't identified until sick people have died in the community and some case-patients' contacts continue to move into areas that have been free of the disease, posing an ongoing risk. Also, the group added that transmission related to survivors continues to be a threat, with more information needed on viral persistence.

The experts raised concerns about the fact that 34 countries still have travel or trade restrictions in place that work against response and recovery efforts. Though some easing of restrictions have been seen, a number of international airlines still haven't resumed flights to the affected countries.

Emergency committees typically meet to reassess the situation every 3 months or as needed based on new developments.
Oct 5 WHO emergency committee statement

New malaria drug found promising in clinical trial

A single dose of an experimental malaria drug called artefenomel (OZ439) appears to be effective and safe in adults from Thailand infected with Plasmodium falciparum or P vivax malaria, according to the findings of a phase 2 clinical trial.

The trial is the drug's first in patients with malaria. An international research team led by Switzerland-based Medicines for Malaria Venture, the nonprofit public-private group developing the drug, published its findings yesterday in The Lancet Infectious Diseases.

Artemisinin-based combination therapy is currently the gold standard against the disease, but resistance in P falciparum is a concern, and standard treatment involves a 3-day course. Artefenomel is a synthetic peroxide that inhibits asexual erythrocytic P falciparum stages. The study took place between October 2010 and May 2012 at two sites in Thailand. It involved 82 adults, with about 20 in each dosage group: 200 mg, 400 mg, 800 mg, and 1,200 mg.

Researchers found that artefenomel cleared parasite blood levels rapidly for both malaria types and that its long half-life makes it a possible candidate for use in combination treatment with other drugs. Adverse effects were mild and reversible, with the most frequently reported effect an asymptomatic increase in plasma creatine phosphokinase concentration. Based on a genetic analysis of the malaria parasites in the study, artefenomel-mediated clearance wasn't greatly affected by mutations related to artemisinin resistance.

The authors concluded that the drug may have potential for a single-dose cure when combined with other drugs, adding that combination-therapy trials are already under way or being planned.

An accompanying commentary by Philip Rosenthal, MD, an infectious disease specialist at the University of California San Francisco, wrote that artefenomel isn't the perfect antimalarial drug, because of its similarity to artemisinins, but its long half-life does offer single-dose possibilities, which is an advance. He also noted the drug may be equally effective against wild-type and artemisinin-resistant parasites, another benefit.
Oct 4 Lancet Infect Dis abstract
Oct 4 Lancet Infect Dis commentary

PAHO reports almost 4,500 new chikungunya cases

The chikungunya outbreak in the Caribbean and the Americas grew by 4,472 cases, to 1,739,354 overall cases, the Pan American Health Organization (PAHO) said in an update late last week.

The week before, the agency reported 12,694 new cases after noting increases of 4,857 and 3,085 cases in the previous two weekly reports. The outbreak total includes 592,585 cases in 2015, PAHO said in an Oct 2 update. The number of outbreak-related deaths stayed the same, at 62 for the year.

Most of the new cases were reported by Brazil, which hadn't reported in 4 weeks. The country has 2,791 new cases, bringing its total to 11,562 cases for the year. Colombia, which had consistently reported the most cases for months, had 1,630 new cases last week, bringing its 2015 total to 335,134. As with past weeks, many countries have not provided a chikungunya update in weeks.

The outbreak began in December 2013 with the detection of the Americas' first locally acquired cases on St. Martin in the Caribbean.
Oct 2 PAHO update