Oct 28, 2010
Mutation commonly linked to severe pandemic H1N1 disease
A study published today found the D222E mutation in the pandemic H1N1 2009 influenza virus to be more commonly associated with severe as well as mild cases of pandemic H1N1 2009 flu than the D222G mutation. Researchers studied hemagglutinin sequences of pandemic H1N1 viruses in 169 Italian patients, focusing on amino acid changes at position 222 because previous studies have suggested they may be linked to more severe disease. They found the D222G substitution in 3 of 52 (5.8%) severe cases and in 1 of 117 (0.9%) mild cases. In contrast, they found the D222E mutation in 20 of 52 (38.5%) severe cases and 37 of 117 (31.6%) mild cases. In addition, a cluster of D222E viruses among school children confirmed human-to-human transmission of that variant.
Oct 28 Eurosurveillance study
Adjuvanted H1N1 vaccine induced rapid immune response in study
A monovalent 2009 H1N1 vaccine containing an oil-in-water adjuvant generated a fast immune response when given to Norwegian healthcare workers during the pandemic, according to a report published online by Vaccine. The vaccine contained 3.75 micrograms of hemagglutinin along with adjuvant, AS03, made by GlaxoSmithKline, and was administered to 207 healthcare workers. Using hemagglutination inhibition assays, the researchers found high rates of protective antibodies in the vaccinees a week after vaccination, and this increased to 98% by 2 to 3 weeks after vaccination. The immune response persisted for at least 3 months in 84% to 92% of the participants. The vaccine was safe and well-tolerated, though the incidence of adverse events was higher than with other H1N1 and seasonal flu vaccines, as 97% of the vaccinees reported mild-to-moderate adverse reactions.
Oct 27 Vaccine abstract
Haiti's cholera toll continues to rise
Cholera cases in Haiti are still climbing and health officials are intensifying efforts to manage the outbreak, Dr John Andrus, deputy director of the Pan American Health Organization (PAHO) said yesterday. According to yesterday's PAHO situation report, Haiti's health ministry has received reports of 4,722 cases and 303 deaths, an increase of 953 cases and 19 deaths. Cases have been identified in Central and West departments, and authorities are investigating suspected cases in North, Northwest, and Northeast departments. Andrus said case counts likely underestimate the true cholera burden. He detailed a new health ministry response strategy that involves strengthening primary care centers to treat mild cases and establishing cholera treatment centers for severe cases. Oral rehydration salts are being distributed to families, and healthcare workers are going to rural and densely populated areas to look for sick people and provide initial rehydration treatment. He said it's difficult to pinpoint the source of the outbreak, even after lab officials compare outbreak isolates with those from other countries.
Oct 27 PAHO press release
Oct 27 PAHO situation report
Meanwhile, United Nations (UN) officials are investigating whether waste trickling from a peacekeeping base in Mirebalais housing Nepalese soldiers played a role in contaminating a waterway with cholera, the Canadian Press (CP) reported yesterday. A UN official confirmed that tests from the base on Oct 22 were negative and that officials were taking more samples to confirm the findings.
Ebola studies detail fatality rate, human vaccine trial
A detailed report on a 2007 outbreak in Uganda's Bundibugyo district involving a novel Ebola strain confirmed that the case-fatality rate (CFR) was lower than seen with the two other strains that cause human illness, researchers from the US Centers for Disease Control and Prevention (CDC) and Uganda reported yesterday in Emerging Infectious Diseases (EID). They noted that CFRs in outbreaks of Zaire and Sudan Ebola strains usually range from 50% to 90%, but the 2007 outbreak involving what is now known as the Bundibugyo strain had a 40% CFR (17 of 43 cases). Like the other two strains that are human threats, the Bundibugyo strain was more lethal in people who were older. Despite the lower CFR, researchers warned that the new strain is a serious public health concern and showed sustained person-to-person transmission
Oct 27 EID report
In other Ebola developments, a phase 1 clinical trial of a recombinant adenovirus Ebola vaccine showed that a single injection is safe and effective, according to a study in Vaccine. The adenovirus vaccine encodes the envelope glycoprotein from Zaire and Sudan Ebola virus species. Thirty-one adults received one of two doses of the vaccine or a placebo. It elicited both Ebola-specific antibody and T-cell responses.
Oct 27 Vaccine abstract
Two more pathogens tied to Minnesota raw-milk farm
Disease surveillance has revealed human cases of Campylobacter jejuni, a bacterium, and Cryptosporidium parvum, a parasite, traced to a Minnesota raw-milk farm that was tied to an Escherichia coli outbreak earlier this year, according to the Minnesota Department of Health (MDH). Epidemiologists have confirmed three cases of Campylobacter infection and four cases of Cryptosporidium infection, according to an MDH news release today. When MDH investigators queried the patients, they all reported consuming raw milk. Those who specified a source named the Hartmann dairy farm in Sibley County, according to the release. Lab tests confirmed that the Campylobacter and Cryptosporidium in "most of the ill people" were genetically identical to organisms found in animal and environmental samples taken on the Hartmann farm in the summer. The farm was implicated as the source of an outbreak of E coli O157:H7 infections in May and June. In response, the Minnesota Department of Agriculture ordered the owner to stop selling milk until he addressed the unsanitary conditions on his farm.
Oct 28 MDH news release