Flu Scan for Mar 18, 2015

News brief

Low-pathogenic H7N3 virus found in California turkey flock

A low-pathogenic avian influenza (LPAI) virus of the H7N3 subtype has hit a commercial turkey farm in California's Central Valley, causing only mild illness in the birds, according to the US Department of Agriculture (USDA).

The virus was found on a farm housing 61,000 18-week-old turkeys in Merced County, which is southeast of San Francisco, the USDA said in a report filed with the World Organization for Animal Health (OIE) yesterday.

H7N3 is a different strain from the highly pathogenic H5N2 and H5N8 viruses that have surfaced in wild birds, backyard poultry flocks, and some commercial poultry farms in the West and Midwest in recent weeks and months. LPAI H7 strains have the potential to mutate into highly pathogenic forms.

The virus was identified after turkeys on the California farm showed coughing and a slight increase in deaths, the USDA reported. Partial sequencing of the virus's hemagglutinin and neuraminidase components (the "H" and "N" in the strain name) indicated the virus is a North American LPAI strain. The numbers of infected and dead turkeys were not reported.

The farm has been quarantined, and surveillance and testing on 10 other epidemiologically linked farms have not revealed any signs of the virus, the USDA said. The report did not mention any plans to euthanize the turkeys.

A highly pathogenic H7N3 virus caused widespread poultry outbreaks in Mexico in 2012 and 2013, but CIDRAP News files don't show any LPAI H7N3 outbreaks in the United States in the last few years. A low-pathogenic H7N3 virus was found in wild swans in Rhode Island in 2008.
Mar 17 OIE report
August 2008 CIDRAP News story on H7N3 in swans

 

Researchers take broader approach to flu vaccine effectiveness

Canadian researchers who used surveillance that linked genotypic, phenotypic, and epidemiologic measures to assess flu vaccine effectiveness (VE) in the 2013-14 season found that VE corresponded to antigenically conserved 2009 H1N1 and well-matched influenza B viruses.

As noted yesterday in the Journal of Infectious Diseases, the authors analyzed data on 663 lab-confirmed flu cases and 1,037 controls. Among the cases, 415 (63%) tested positive for 2009 H1N1, 15 (2%) for H3N2, 191(29%) for B/Yamagata lineage, and 6 (1%) for B/Victoria lineage.

VE for the 2009 H1N1 strain, which was well matched with the vaccine strain, was 71%. Likewise, B/Yamagata VE was 73% overall, but it was 63% for clade-mismatched strains, compared with 88% for clade-matched strains.

The authors concluded, "VE corresponded with antigenically-conserved A(H1N1)pdm09 and lineage-matched B/Yamagata viruses with clade-level variation. Surveillance linking genotypic, phenotypic and epidemiologic measures of vaccine-virus relatedness and effectiveness could better inform predictions of vaccine performance and reformulation."
Mar 17 J Infect Dis abstract

 

Intervention tool has little effect on HCW flu vaccination rates

A tool developed by experts to increase rates of flu vaccination in healthcare workers (HCWs) had little impact in Canadian hospitals, a study yesterday in PLoS One found.

Canadian researchers randomly assigned 26 healthcare organizations in six provinces equally to implement a guide for hospital program planners or to conduct vaccination programs as usual (the controls). The guide was developed after expert consultation and review of multiple studies. Nine of the sites (35%) were acute-care hospitals, 5 (19%) were longer-term care facilities, and 12 (46%) were mixed or were regional health authorities.

The median rates of flu immunization among HCWs for the intervention group were 43%, 44%, and 51% at three study points, respectively, which were the baseline year (2008-09) and 2010-11 and 2011-12. That compares with 62%, 57%, and 55%, respectively, in the control group.

No significant differences were observed between the groups at the three points in time. The intervention group, however, saw an increase in the median vaccination rate from the baseline year to 2011-12 that was statistically significantly different from the decrease in the control group over that time.

The authors also noted that the intervention group reported that making the changes recommended in the flu vaccination guide required substantial organizational changes.
Mar 17 PLoS One study

News Scan for Mar 18, 2015

News brief

CDC: Despite warning, drug for tick-borne disease doesn't harm kids' teeth

Concern over a potential for causing dental staining often prevents doctors from using the best drug to treat Rocky Mountain spotted fever (RMSF) in young children. But a new study suggests that this concern is groundless, says the Centers for Disease Control and Prevention (CDC).

The agency said doxycycline, the most effective antibiotic for RMSF, carries a label warning about a risk of tooth staining in children less than 8 years old. Children are five times more likely than adults to die of tick-borne diseases like RMSF, the CDC noted.

To test the concern about doxycycline-linked dental staining, researchers from the CDC and the Indian Health Service examined the medical records and teeth of more than 250 children who lived on an American Indian reservation with high rates of RMSF. Their study was reported yesterday in the Journal of Pediatrics.

Dentists inspected the permanent teeth of 58 children who had received doxycycline for suspected RMSF before their 8th birthday and 250 who had not, without knowing which children had received the drug, according to the journal article. They found no "tetracycline-like staining" in any of the children's teeth and no significant difference in tooth shade or enamel.

Since 1970, all tetracycline-class antibiotics have carried a warning label about a risk of dental staining in young children, the CDC said. The warning was based on studies of children who received older tetracyclines.

The agency said that for RMSF, doctors must prescribe treatment early, before they have lab confirmation of the infection.

Jennifer McQuiston, DVM, MS, a CDC epidemiologist and a coauthor of the study, said the findings show clearly that the concern about dental effects "shouldn't be a reason to avoid this life-saving drug. Changing the drug's label may encourage physicians to use doxycycline earlier to treat suspected RMSF in children, which will help save lives."
Mar 17 CDC press release
Mar 17 J Pediatr report

 

Four killed, one injured in Pakistani polio vaccination campaigns

Three health workers administering oral polio vaccine to children in Pakistan and a police officer have been killed, plus another worker injured, according to media sources today.

A story in Karachi-based The News International reports the death of two women and a guard working in Danna, in the Mansehra district in the northeastern part of the country, during the second of a 3-day polio vaccination campaign in the area. An unidentified gunman attacked them and has not yet been apprehended.

Government officials condemned the violence, and other members of the "Ladies Health Workers Association" vowed to continue their work after a 3-day period of mourning.

In a separate attack in Bajaur, which lies in the Federally Administered Tribal Areas of northwestern Pakistan, a gunman killed one member of a vaccination team and injured another, who was rushed to the hospital, says a story in Pakistan Today. A Taliban group took responsibility for the attack.

Militants who consider the vaccination efforts to be acts of espionage from the West have killed 76 health team members and security personnel since December 2012, says the Pakistan Today article. Polio remains endemic in only three countries—Afghanistan, Nigeria, and Pakistan—with the latter seeing more than 300 cases last year, the highest in 14 years.
Mar 18 News International story
Mar 18 Pakistan Today story

 

Uganda home to typhoid fever outbreak of nearly 2,000 cases

An outbreak of typhoid fever in Uganda has reached 1,940 cases as of Mar 5, according to a statement yesterday from the World Health Organization (WHO).

Cases began in downtown Kampala City early this year and have since spread to all parts of the city and its outskirts. Young men aged 20 to 39 years are most affected, and most case-patients are casual laborers or in the business sector, including food/juice vendors and cooks, says the notice.

The main sources of infection identified to date are contaminated drinking water and juices, the WHO said. Salmonella Typhi and Salmonella Paratyphi group A bacteria have been identified in laboratory testing. Symptoms of typhoid fever can include fever, headache, malaise, constipation, diarrhea, spots on the chest, and an enlarged spleen and liver; paratyphoid is similar but typically follows a more benign course.

A task force in Uganda, with support from the WHO and other organizations, has improved surveillance and implemented control measures, including provision of safe water.
Mar 17 WHO report

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