Oral killed cholera vaccine shown 53% effective in real-life use
A large study in Bangladesh of oral killed whole-cell cholera vaccine found that it cut disease rates in half, even with moderate coverage, according to a report yesterday in The Lancet.
Bangladeshi and US researchers analyzed data on 267,270 participants; 94,675 received two doses of Shanchol vaccine (made by Shantha Biotechnics-Sanofi), 92,539 received the vaccine and made cholera-avoiding behavioral changes, and 80,056 received no intervention. Vaccine coverage was 65% in the vaccination-only group and 66% in the vaccination-plus-behavioral-change group.
For those who received two doses of the vaccine, total effectiveness was 53% in the vaccination-only group and 58% in the vaccination-plus-behavioral-change group at 2-year follow-up. The team also noted 37% overall protection against severely dehydrating cholera in the vaccine group and 45% overall protection against that form in the vaccine-plus-behavior-change group.
The authors conclude, "Our results show that even with moderate coverage, the incidence of severely dehydrating cholera was reduced by oral cholera vaccination in the study population, irrespective of vaccination status, when vaccine was administered via routine government services in a densely populated urban setting."
UK experts in an accompanying commentary wrote that although oral cholera vaccination has been shown effective in previous trials, the new study "showing its feasibility and effectiveness under real-life conditions, is a welcome step towards vaccine deployment in endemic settings."
The study was funded by the Bill & Melinda Gates Foundation.
Jul 9 Lancet abstract
Jul 9 Lancet commentary
May 29, 2014, CIDRAP News story "Study: Cholera vaccine worked well during outbreak"
Oct 18, 2013, CIDRAP News story "Cholera vaccine yields 5-year protection, finds acceptance"
Review of West Nile virus studies finds long-term effects common
Studies of West Nile virus cases suggest that muscle weakness, fatigue, pain, and cognitive effects persist in many patients for months or years, according to a systematic review published this week in The Lancet Infectious Diseases.
Researchers from Toronto found 67 studies that met their criteria, including 30 that looked at West Nile neuroinvasive disease (WNND) only, 4 that examined only West Nile fever (WNF), 30 that covered both forms of the disease, and 3 in which the diagnosis was unknown or not reported.
The most common lingering physical effects, reported in 24 studies, were muscle weakness, fatigue, and myalgia, the report says. For example, muscle weakness persisted in 7% to 73% of patients with WNND for 3 to 18 months, 12% to 24% of those with WNF for 1 to 6 months, and 7% to 73% of those in combined studies for 1 month to 8 years.
Similarly, fatigue was reported in 48% to 75% of WNND patients for 8 to 18 months, in 48% of WNF patients for 30 days, and in 20% to 84% of patients in combined studies for 1 month to 8 years. The percentages were somewhat lower for lingering myalgia, for example, 19% to 49% of WNND patients (6 to 12 months).
The most common cognitive or psychological sequelae, reported in 19 studies, were memory loss (in up to 59% of patients), depression (up to 41%), and difficulty concentrating (up to 48%). Problems with activities of daily living were common.
The authors said the studies involved a wide variety of methods, and more than half of those that reported sequelae relied exclusively on subjective assessments. "Therefore, opportunities exist for more robust primary studies," they concluded.
Jul 7 Lancet Infect Dis abstract
White House denies Iowa request for avian flu disaster declaration
The Obama administration has turned down Iowa Gov. Terry Branstad's request for a federal disaster declaration in response to the avian influenza outbreaks in the state, the Associated Press (AP) reported yesterday.
Branstad had asked for a major disaster declaration for the four counties hit hardest by the virus, the story said. The request was rejected in a letter dated Jul 7, which said the damage was "not of such severity and magnitude" that the state couldn't handle it.
Branstad spokesman Jimmy Centers told the AP that the administration was gathering information to assess whether an appeal of the decision would be effective. The state has lost more than 31.5 million birds to the virus and precautionary culling of flocks.
Jul 8 AP story
Beef slaughterhouse kill steps reduce Salmonella, E coli, FSIS says
Food safety measures at beef slaughter plants seem to be reducing levels of Salmonella and Escherichia coli on carcasses, Food Safety News reported today, citing federal data.
The US Department of Agriculture's Food Safety and Inspection Service (FSIS) last week released data from the first 6 months of surveys meant to establish baseline levels of the two pathogens on beef and veal carcasses. They showed drops in both Salmonella and E coli levels after interventions.
The FSIS found 24.5% of beef carcasses were contaminated with Salmonella immediately after slaughter and hide removal, but this dropped to 3.9% after a kill step such as a hot water or lactic acid wash. E coli O157:H7 prevalence dropped from 1.6% to 1.1% after the kill step, and non-O157:H7 E coli rates dropped from 8.4% to 1.8%, according to FSIS data.
"These results suggest that the interventions are reducing the pathogens on the beef and veal carcasses," the FSIS said. It plans to release an official report in 6 months, after a year of surveying.
Jul 9 Food Safety News story
Jul 2 FSIS update