News Scan for Nov 09, 2017

News brief

Snapshot of H7N9 patients highlights importance of early antivirals

A retrospective review of confirmed H7N9 avian influenza infections from China's Guangdong province to learn more about the demographics, disease severity, and treatment found that early oseltamivir treatment was linked to fewer intensive care unit (ICU) admissions and deaths. A research team from the Guangdong Province Center for Disease Control and Prevention reported their findings yesterday in the International Journal of Infectious Diseases.

Guangdong province, which produces 10% of China's domestic poultry, had no human H7N9 cases during the country's first wave of H7N9 activity in 2013, but was hard hit during the next four waves.

For the study, researchers looked at medical records of 256 cases that were confirmed from August 2013 through March 2017. Among the group, 100 (39%) died, and 168 (66%) were admitted to the ICU.

The most common early symptoms were fever, cough, and fatigue. Consistent with earlier studies, H7N9 illness was more common in male, elderly, retired, and peasant-class people, as well as in those with frequent exposure to live poultry.

About 40% of patients receive glucocorticoids for treatment, which is not recommended by World Health Organization guidelines. The authors said this finding suggests standard treatment protocols need to be beefed up in the province.

Oseltamivir was administered to 83% of the patients, with others receiving zanamivir or peramivir, and some receiving more than one antiviral drug. Time from symptom onset to treatment was about 5 days for oseltamivir, a shorter interval than for the other two drugs.

Earlier H7N9 confirmation and treatment with oseltamivir was linked to reduced risk of ICU admission, and earlier treatment with oseltamivir or zanamivir was associated with a lower risk of death.

The team concluded that driving down the risk of H7N9 should include targeting high-risk populations—especially men and elderly people—with preventive measures and ensuring that patients receive early antiviral treatment.
Nov 8 Int J Infect Dis study


Japan, Taiwan report new avian flu outbreaks

In the latest avian flu outbreak developments, Japan has detected highly pathogenic H5N6 in a mute swan found dead near a lake and Taiwan has reported another highly pathogenic H5N2 outbreak in poultry, this time at a duck farm.

Japan reported H5N6 in wild birds, then poultry, for the first time last fall. The strain has been linked to 17 human infections, often fatal and all in China. News of the latest detection came in a report today from Japan's agriculture ministry, which was translated and posted by Avian Flu Diary (AFD), an infectious disease news blog. According to the report, two mute swans have been recovered from Shinji Lake in Shimane prefecture, and one has tested positive for H5N6; tests on the second bird have so far revealed influenza A.

Elsewhere, Taiwan yesterday reported another in a long string of H5N2 outbreaks that have affected the island's poultry sector since early 2015. According to a report from the World Organization for Animal Health (OIE), the outbreak began on Nov 1, killing 2,565 of 6,250 susceptible ducks at a farm in Yunlin County on the west side of the island. The surviving birds were culled to control the spread of the virus.
Nov 9 AFD post
Nov 8 OIE report on H5N2 in Taiwan


CDC data show steady drop in meningococcal disease after vaccine intro

Meningococcal disease in the United States has declined steadily in the past 20 years, with reductions of serogroups contained in the MenACWY vaccine suggesting a benefit of immunization, researchers from the Centers for Disease Control and Prevention (CDC) reported yesterday in Clinical Infectious Diseases.

The MenACWY meningococcal conjugate vaccine was recommended in 2005 for routine use in children and teens aged 11 to 18 years. The CDC investigators looked at data in the decade before and after that step, from 1996 through 2015.

During that time, 7,924 cases of meningococcal disease were reported to the National Notifiable Diseases Surveillance System (NNDSS), the CDC's national database, and 15% of them proved fatal. Among cases with serogroup information, group B was most common (35.8% of cases), followed by Y (28.5%), C (22.8%), and W (6.8%).

After MenACWY introduction, the incidence of meningococcal disease declined from 0.40 cases per 100,000 population in 2006 to 0.12 cases per 100,000 population in 2015, a drop of 70%. The incidence of serogroups B, C, and Y all declined over the study period, while the incidence of A, W, and other strains stayed relatively stable.

The authors concluded, "Declines in meningococcal disease incidence in the United States have been observed among all age groups and predominant serogroups (B, C, and Y). Reductions in the incidence of meningococcal disease due to serogroups A, C, W, and Y among adolescents suggest an impact of the MenACWY vaccine program in this age group."
Nov 8 Clin Infect Dis study

Stewardship / Resistance Scan for Nov 09, 2017

News brief

Increased sepsis risk found in patients previously treated with antibiotics

A significant increase in cases of severe sepsis and septic shock within 90 days of hospital discharge was observed among patients exposed to antibiotics during their previous hospital stay, researchers with the Centers for Disease Control and Prevention reported today in Clinical Infectious Diseases.

For the study, the researchers obtained hospital discharge and drug use data from a large database that contains billing records from more than 500 US hospitals. They included hospital admissions for all patients discharged during two periods: January 2007 through September 2010 and January 2011 through September 2014. The purpose was to examine the association between the use of certain antibiotics during the initial hospital stay and the risk of post-discharge sepsis, using a multivariable logistic regression model that controlled for potential confounding factors. The antibiotics were categorized into high-risk, low-risk, and control categories, based on association with clinically important microbiome disruption.

Among 516 hospitals, the researchers randomly selected more than 12 million patients who had a hospital stay during the study period and identified 21,247 (0.17%) who had severe sepsis or septic shock during within 90 days of their index stay. Among patients with exposure to a high-risk antibiotic agent—including third- and fourth-generation cephalosporins, fluoroquinolones, licnosamides, beta-lactam/beta-lactamase inhibitor combinations, oral vancomycin, and carbapenems—during the index stay, the proportion of patients with severe sepsis post-discharge was 0.3%, compared with 0.1% of patients with no antibiotic exposure.

In the multivariable logistics regression model, exposure to a high-risk antibiotic was associated with a 65% increased risk of severe sepsis within 90 days of discharge (odds ratio [OR], 1.65). Exposure to low-risk and control antibiotics were not as strongly associated with severe sepsis (OR, 1.07 and OR, 1.22, respectively). Patients exposed to four or more antibiotic classes or more than 14 days of antibiotic therapy had over twice the risk of severe sepsis (OR, 2.23 and OR, 2.17, respectively).

The authors say the findings support the hypothesis that microbiota disruption is associated with an increased risk of severe sepsis post-hospital discharge. They also argue that the study makes a case for increased antibiotic stewardship, given that 30% to 50% of antibiotic use in hospitals is estimated to be inappropriate. "This study builds on a growing evidence base suggesting that increased stewardship efforts in hospitals may not only prevent antimicrobial resistance, CDI [Clostridium difficile infection] and other adverse effects, but also reduce other unwanted outcomes potentially related to disruption of the microbiota, including sepsis," they write.
Nov 9 Clin Infect Dis study


Study finds no MCR genes in Shiga toxin–producing E coli in California

Molecular screening of 1,000 Shiga toxin–producing Escherichia coli (STEC) isolates from an agricultural region in California detected no colistin resistance genes, investigators from the US Department of Agriculture reported yesterday in PLoS One.

The STEC isolates were recovered from livestock, wildlife, produce, and other environmental sources in California's central coast from 2006 through 2014. They included STEC O157 and non-O157. STEC is recognized as the leading cause of foodborne illness outbreaks in the United States.

The investigators screened the isolates for the presence of MCR-1 and MCR-2, the plasmid-mediated colistin-resistance genes that were first identified in Chinese pigs in 2016 and since then have spread around the world. Recent studies have found the presence of MCR-1 in some STEC isolates.

The results obtained via polymerase chain reaction (PCR) testing showed that all 1,000 STEC isolates were negative for MCR genes, a finding that suggests "a very low probability" that MCR genes are prevalent in STEC recovered from the region. The authors say the findings also indicate a lower prevalence of transferable colistin resistance in the United States when compared with other countries, especially those where colistin use in food-producing animals has been uncontrolled.
Nov 8 PLoS One study

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