Flu Scan for Aug 27, 2015

News brief

H5N1 hits more farms in Ivory Coast, Nigeria

Highly pathogenic H5N1 avian influenza stuck two more commercial farms in Ivory Coast and Nigeria, according to separate reports from the World Organization for Animal Health (OIE).

Ivory Coast's outbreak was detected at a farm housing broilers and layers in Aboisso state, on the country's southeastern coast. The outbreak began on Jul 17, and the virus killed 20,286 of 27,652 susceptible birds. The survivors were culled to control the spread of the virus. Health officials pinned the source of the outbreak on the introduction of new live animals.

Nigeria's latest outbreak began Aug 10, hitting layers and broilers at a farm in Gombe state, located in the east central part of the country. The report noted that ducks and pigeons were also kept at the farm. Of 1,000 at-risk birds, the virus killed 350. It's not clear if the site was depopulated, but other control steps included disinfection, quarantine, and control of poultry movements. So far the source of the virus hasn't been determined.

A handful of African countries have seen H5N1 resurgence in poultry after a several-year hiatus. Global health officials have called for increased resources and efforts to battle the outbreaks, one of several recent worldwide avian influenza patterns that pose threats to food supplies and human health.
Aug 25 OIE report on Ivory Coast outbreak
Aug 26 OIE report on Nigerian outbreak

 

H7N9 studies shed light on Chinese poultry patterns, gender differences

Two recent studies revealed more about H7N9 avian influenza patterns in China, one showing a link between virus contamination in poultry markets and human illnesses and one suggesting that women of childbearing age may be more vulnerable to the virus.

The poultry sampling study took place in Zhejiang province, one of the hardest hit during China's H7N9 outbreaks. The team from China published their findings yesterday in Public Library of Science (PLoS) One.

Between January 2013 and March 2014 researchers obtained and tested 6,740 samples from 751 poultry environment sites from 11 of the province's cities. They explored the relationship between positive samples and human illnesses, as well as seasonal and geographic patterns. The testing period covers the first two waves of H7N9 activity in China.

About 10% of the environmental samples were positive for H7N9, with peaks seen in the spring and winter. Prevalence decreased from north to southeast, similar to the distribution of human cases. Of the different poultry environments, live markets had the highest prevalence, with chopping board swabs showing the highest virus prevalence among the different sample types analyzed.

The prevalence of virus in the environment correlated with incidence of human cases (r2 = 0.498; P < 0.01); cities with higher H7N9 incidences had more H7N9 among samples and sampling sites.

Poultry market closures in late January 2014 led to decreased H7N9 environmental positives, declining from about 19% to nearly 7%, in line with a drop in human infections.
Aug 26 PLoS One abstract

In another recent study, a German and Chinese research team that analyzed human H7N9 cases found that women in their childbearing years seemed more likely to die from their illnesses; the authors' tests on mice with different flu strains also found that females were more severely affected, especially those infected with H7N9. They reported their findings in an Aug 25 early online edition of Vaccine.

The researchers' analysis of human cases included 535 lab-confirmed cases, of which 197 were fatal, compiled by the Chinese Center for Disease Control and Prevention as of Jan 25, 2015. Though more men were infected in the outbreak, females in their reproductive years were more likely to die from their illness (female-to-male ratio = 1.2), a pattern found in earlier studies.

The group's mouse studies found increased cytokine and chemokine response in female mice, which corresponded to disease severity. The researchers also found reduced thrombocyte and neutrophil responses in female mice.

In conclusion, they said more animal studies are needed to determine the factors that lead to more severe flu infections in females and that the study findings could help guide vaccine priorities when supplies are scarce.
Aug 25 Vaccine abstract

 

Oceania, Cuba, China still seeing flu activity, quiet elsewhere

Influenza activity through Aug 9 reported Aug 24 by the World Health Organization (WHO) shows cases in Australia and New Zealand still increasing in number, cases in temperate South America peaking, and cases in South Africa decreasing.

The strains predominating in Oceania are H3N2 and influenza B.

Cuba reported high levels of influenza-like illness and severe respiratory infections associated with the 2009 H1N1 strain and respiratory syncytial virus detections. Southern China still has a high but decreasing level of predominately H3N2 flu.

Northern Hemisphere countries are seeing low levels of activity, with some countries ceasing or reducing surveillance until the start of the next flu season. Other areas with decreasing or low activity include those in both Eastern and Western Africa, tropical Asia, and most of tropical Central America and the Caribbean.
Aug 24 WHO update

 

News Scan for Aug 27, 2015

News brief

India eliminates maternal and neonatal tetanus ahead of schedule

The World Health Organization (WHO) today announced that all of India's 675 districts have eliminated maternal and neonatal tetanus.

Maternal and neonatal tetanus cases in India have been reduced to less than one case per 1,000 live births ahead of the elimination target date set for December 2015.

Elimination can be attributed to programs that directly addressed maternal vaccination and unhygienic obstetric care, especially among impoverished or isolated populations. India's Mission Indradhanush provided tetanus immunization campaigns directed at children and pregnant women, while the National Rural Health Mission and Janani Suraksha Yojana promoted in-facility perinatal and birthing care.

The WHO said that, given the prevalence of tetanus in the environment, vaccination and hygiene campaigns will require ongoing collaboration between government and community health entities in order to prevent future cases.
Aug 27 WHO press release

 

WHO announces global water sanitation plan to target tropical diseases

The WHO today announced a plan to integrate water sanitation programs with four public health interventions to reduce the global burden of neglected tropical diseases (NTDs) by 2020.

NTDs such as leprosy, trachoma, and schistosomiasis affect more than 1 million people and cause more than 500,000 deaths each year. The WHO plan proposes integrating improved water and sanitation programs with interventions that provide preventive NTD chemotherapy, innovative and intensified disease management, vector control, and veterinary public health.

The global strategy focuses on strengthening the evidence base for water and sanitation improvement in impoverished communities, improving collaborations between governments and local health workers, and addressing the role of poverty and inequality in access to water and risk of disease.

Given that 660 million people lack access to clean water sources and 2.5 billion do not have adequate sanitation, addressing contaminated water's role in disease is expected to lead toward significant progress in eliminating or eradicating 16 of 17 targeted NTDs.
Aug 27 WHO strategy

 

Companies asked to contribute samples to federal food pathogen network

A new approach to finding the source of foodborne disease outbreaks that involves a network of state and federal labs mapping out the entire DNA sequences of various strains of food pathogens and a public database housing the information is "radically transforming" investigations, and food companies are being asked to help, said a Reuters story yesterday. The system aims to considerably shorten the time it takes to get contaminated foods out of circulation and thus lessen the burden of foodborne diseases.

The network is being constructed by the US Food and Drug Administration (FDA); the database, known as GenomeTrakr and housed at the National Institutes of Health (NIH), not only stores the sequences of strains from patients ill with such diseases as Salmonella and Listeria but also contains pathogens identified during routine FDA inspections at food plants.

The FDA is asking food manufacturers to voluntarily contribute samples from their facilities to the database as well, although "convincing companies to offer up potentially incriminating evidence has been a hard sell," says the story.

Since GenomeTrakr's inception in 2012, 25,000 genomes have been added to the database. In 2013, the first year the system was used to experiment with Listeria sequences, 19 clusters of illness were identified and 4 outbreaks solved. This compares with identification of 14 clusters and solution of 1 outbreak the previous year using the older method of comparing pulsed-field gel electrophoresis (PFGE) results from ill patients.

David Acheson, MD, a former official at the FDA and the US Department of Agriculture (USDA), compared the two methods to witnessing a hit-and-run accident, saying "While PFGE might identify the vehicle as a brown Toyota Corolla, whole genome sequencing provides the license number and even the vehicle identification number," according to the story.

The Centers for Disease Control and Prevention and the USDA have "signed on" to the program.
Aug 27 Reuters story

 

Pediatric pneumococcal vaccination has protective effect on adults

Pneumococcal vaccine coverage in children protects adults from invasive pneumococcal disease (IPD) at a local level, according to a study yesterday in the Journal of Infectious Diseases.

Researchers from the Yale School of Public Health and the Connecticut Department of Public Health analyzed ZIP code–level data on pediatric immunization with at least three or four doses of pneumococcal conjugate vaccine 7 (PCV7) from Connecticut's state immunization registry. Data were compared with ZIP code–level incidence of IPD in Connecticut between 1998 and 2009 and US Census data on race, income level, and population density at the local level.

Between 1998 and 2009, Connecticut reported 5,838 cases of IPD, 2,313 of which were caused by PCV7 serotypes. People aged 40 to 64 years accounted for 1,947 of all IPD cases, and 2,375 cases occurred in people 65 years of age and older.

Connecticut's immunization registry contains data on 176,923 children. By 2009, 95% of them had received three doses of PCV7, and 88% had received four doses (three doses plus booster).

After PCV7 was introduced in 2000, IPD rates declined each year by an average of 63% in children under 5 years of age, 36% in adults 40 to 64, and 37% in people 65 and older. By 2008, fewer than 8% of IPD cases in adults 40 years and older were caused by the seven serotypes covered by the vaccine.

ZIP codes with a higher proportion of children who did not receive the fourth dose of PCV7 had a higher proportion of adult IPD cases caused by PCV7 serotypes. When a gap of ten percentage points was observed between children who received the third and fourth doses, the odds of an adult case of IPD caused by a PCV7 serotype increased by 54.3% (95% confidence interval, 20.2%-98.2%).

The ZIP codes with a lower pediatric uptake of the booster dose were also significantly more likely to have a higher population density and a higher proportion of Hispanic and/or Black residents and children under 5 years of age.

The investigators noted that their results may not translate to effects of the PCV13 vaccine, which the United States began using instead of PCV7 in 2010.
Aug 26 J Infect Dis study

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