Swine reassortant suggests 2009 H1N1 virus could cause more trouble
Scientists have found a hybrid influenza virus in swine that combines elements of the pandemic 2009 H1N1 virus and a Eurasian swine flu virus, suggesting that continued circulation of the pandemic virus in pigs could lead to novel viruses with the ability to infect humans, according to a report published yesterday in the Journal of Virology. The detection of the pandemic virus in pigs prompted a flu virus surveillance program for pigs at slaughterhouses in southern China, according to the report by Chinese and American researchers. More than 50% of the pigs tested were found to be seropositive for one or more H1 flu viruses. Among 36 isolates detected, one group had surface genes from a Eurasian avian-like H1N1 virus and internal genes from the 2009 H1N1 strain. Experiments showed that the virus could spread among pigs and from pigs to ferrets, and it could grow in human lung tissue in a laboratory. Also, ferrets that were immunized against the 2009 H1N1 virus had only partial protection against the reassortant strain. The authors say the continuing prevalence 2009 H1N1 virus in pigs "could lead to the genesis of novel swine reassortant viruses with the potential to infect humans."
Aug 17 J Virol abstract
Study suggests pandemic flu virus could emerge directly from poultry
A genetic analysis of avian and human influenza viruses associated with the H7N7 avian flu outbreak in the Netherlands in 2003 suggests that flu viruses capable of causing a pandemic can emerge directly from poultry without passing through an intermediate host, says another report published yesterday by the Journal of Virology. The 2003 H7N7 outbreak prompted the culling of 28 million birds and led to more than 80 human cases and one death, according to previous reports. To map the acquisition of human adaptation markers, Dutch researchers conducted a comprehensive analysis of both avian and human H7N7 viruses isolated during the outbreak. They found amino acid variations in the hemagglutinin, neuraminidase, and PB2 genes in isolates from 45 human cases. In examining poultry isolates, they found that about 50% of the variation in each gene was already present in poultry. They concluded that virus variants with two particular mammalian host determinants had spread from farm to farm. "This implies that HPAI viruses with pandemic potential can emerge directly from poultry," the authors write. They recommend monitoring for human adaptation markers on both avian and human viruses during avian flu outbreaks.
Aug 17 J Virol abstract
Reported legionellosis incidence nearly tripled in a decade
The nationally notifiable disease legionellosis, comprising Legionnaires disease (LD) and the milder Pontiac fever, has grown in crude incidence in the United States from 0.39 cases in 2000 to 1.15 in 2009 (an increase of 192%) and in age-adjusted incidence from .0.40 to 1.08 (170% increase), according to an article in tomorrow's Morbidity and Mortality Weekly Report (MMWR). The disease is among those reportable through the National Notifiable Disease Surveillance System (NNDSS); reporting through the Supplemental Legionnaires Disease Surveillance System (SLDSS), which collects information on more variables than the NNDSS as well as on travel-related outbreaks, is also encouraged. The total number of cases reported through NNDSS by the 50 states and the District of Columbia over the 10-year period was 22,418; the annual number of cases grew from 1,110 in 2000 to 3,522 in 2009. LD accounted for the large majority of cases. The report says that because NNDSS is a passive surveillance system, the actual incidence is probably higher. Reasons for the increased incidence will be assessed through the Active Bacterial Core surveillance (ABCs) system, to which legionellosis was added in January 2011.
Aug 19 MMWR article
Death toll grows in Cameroon cholera outbreak
A cholera outbreak in Cameroon has killed about 500 people this month and has sickened about 13,000 so far this year, CNN reported yesterday. The hardest hit area is the country's Far North region, where the disease is primarily striking children under age 5 and women. Gervais Ondobo Andze, director of disease control for Cameroon's health ministry, told reporters that 9 of the country's 10 regions are affected by the disease. He is advising residents to avoid getting their water from rivers, which can be contaminated. Sanitary inspectors have said few citizens have toilets in their homes. The semi-arid region has an uneven supply of potable water, and many residents rely on wells and streams for drinking and cooking. In other cholera developments, the international aid organization Oxfam said today that it is airlifting 47 tons of supplies into Somalia's capital, Mogadishu, to help fight a cholera outbreak hitting that city, as well as to camps housing refugees who have fled drought, famine, and civil war. Supplies include water tanks and pipes to set up water supplies, soap, and cans for people to carry and store water. The group said the aid is intended to reach over 120,000 people.
Aug 17 CNN story
Aug 18 Oxfam press release