Report: Flu, pneumonia top list of infectious disease causes in US
A research letter published today in JAMA said that although mortality from infectious diseases remains low in the United States, influenza and pneumonia account for nearly 40% of all infectious disease deaths. Those common illnesses, along with HIV, drug-resistant pathogens, and vector-borne diseases such as West Nile virus accounted for any spikes in infectious disease mortality from 1980 to 2014.
The investigators looked at infectious disease mortality trends from the past 34 years and compared them to earlier 20th century trends. From 1980 through 2014, infectious diseases composed 5.4% of deaths in the United States. Infectious disease mortality declined steadily in the United States between 1900 and 1950 (save the 1918 flu), but plateaued in the 1980s, most likely due to the introduction of HIV.
Though HIV deaths have now declined, drug-resistant pathogens are a novel threat. "Mortality due to vaccine-preventable diseases declined, whereas mortality due to pathogens with resistant strains remained stable," the authors concluded.
Nov 22 JAMA letter
H5N6 confirmed in Japanese zoo; novel clade and receptor binding
A report to the World Organization for Animal Health (OIE) today confirmed that H5N6 caused the deaths of two black swans housed in a Japanese zoo. The birds were found dead at a zoo in Akita on Nov 15 and 17.
In recent weeks, H5N6 and H5N8 have been appearing in waterfowl in Japan and South Korea, following regional migration patterns. Japan is a migratory home to many of the world's cranes and swans in the winter months.
Nov 22 OIE report
In other avian flu news, Dutch and US collaborators reported yesterday in Emerging Infectious Diseases (EID) that the emergence and intercontinental spread of the current H5N8/H5N2 virus clade 2.3.4.4 has been accompanied by a change in receptor-binding specificity, possibly making the virus more easily transmissible this season.
Also in EID yesterday was a letter detailing H5N8 from the same clade in Siberian waterfowl. In June 2016, researchers collected samples from 13 dead and 30 hunter-harvested wild aquatic birds around Uvs Lake (Tyva Republic) at the Russia-Mongolia border.
"Because numerous species of migratory shorebirds and waterfowl use the summer breeding grounds of Siberia, the identification of HPAIV [highly pathogenic avian influenza virus] infection in wild aquatic birds in this area signifies the potential for wide dissemination of these novel reassortant Group B H5N8 viruses during the 2016 fall migration," the authors write.
The emergence of novel H5 viruses resulted in the culling of more than 7 million turkeys and 42 million chickens in the United States in 2014-2015, and 13 human deaths from H5N6 in Asia during the same period. This year, the H5N6 clade first identified in Russia has already been reported in more than a dozen countries.
Nov 22 EID study
Nov 22 EID letter
Chemoprevention of malaria successful in older children
Current recommendation suggests that seasonal malaria chemoprevention (SMC) be given to children under the age of 5 during malaria season, but a study conducted in Senegal and published today in PLoS Medicine suggest that SMC is effective in reducing malarial episodes in children up to the age of 10.
In the study, children between the ages of 3 months and 10 years were given sulfadoxine-pyrimethamine plus amodiaquine each month during the transmission season over 3 years in central Senegal (2008-2010). A 60% reduction of malaria cases confirmed by a rapid diagnostic test and a reduction of 69% in the number of treatments for malaria (confirmed and unconfirmed) was observed in the children.
According to the study, estimates of the reduction in the prevalence of parasitemia at the end of the transmission season in SMC areas was 68% in 2008, 84% in 2009, and 30% in 2010. SMC costs about $0.50 per child per month
In an editorial about the study, epidemiologist Robert W. Snow, PhD, writes, "When SMC coverage is as high as 80% and insecticide-treated net (ITN) use is also high, these combined interventions will continue to change the epidemiology of parasite exposure and the clinical landscape."
Nov 22 PLoS Med study
Nov 22 PLoS Med editorial
