Top Infectious Disease News of the Week—September 16, 2018

#5: Severe Varicella-Related Hospitalizations Occur in Vaccinated, But Mostly Unvaccinated Children

Severe hospitalized cases of varicella occur primarily in unvaccinated children, yet these cases are still reported in children in a 1-dose vaccination program, according to a study in the Journal of Infectious Diseases. Additionally, the investigators found that viral genotyping was important for monitoring disease caused by the Oka-vaccine strain in complex hospitalized cases.

“In an era of 1-dose varicella programs in Australia, continued strain surveillance is important: virus genotyping should especially be considered in children with VZV disease who have previously been vaccinated with varicella vaccine or who are immunocompromised,” the investigators, led by Helen Marshall, MD, wrote.

“Our results show varicella breakthrough disease due to waning immunity or primary vaccine failure was responsible for over a quarter of hospitalized cases, although over half of these cases were in immunocompromised children,” they added.

Read more about varicella-related hospitalizations.

#4: Enterovirus A71 Neurologic Disease Detected in 34 Children in Colorado

Enterovirus-A71 (EV-A71) is 1 of more than 100 non-polio enteroviruses. It was first identified in the United States in 1969 as a common cause of hand, foot, and mouth disease. In rare circumstances, EV-A71 can also cause severe neurologic diseases such as meningitis, encephalitis, and acute flaccid myelitis (AFM).

On May 10, 2018, the Colorado Department of Public Health and Environment (CDPHE) was notified of an influx of cases of meningitis and encephalitis in infants who also tested positive for EV-A71 at the Children’s Hospital Colorado (CHCO).

Surveillance data for the month of May showed a 2.75-fold increase in encephalitis as well as a 3-fold increase in enterovirus/rhinovirus compared with the 5-year average.

Read more about enterovirus A71.

#3: Potential Single Dose Influenza Treatment, With Caveats

Two classes of antivirals are approved for the prevention and treatment of influenza: adamantanes (amantadine and rimantadine) and neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir). However, because of high resistance rates (>99%), adamantanes are no longer recommended for prophylaxis or treatment of influenza A. For the 2017-2018 season, although the majority of circulating viruses were susceptible to the neuraminidase inhibitors, approximately 1% of the H1N1pdm09 viruses were resistant to oseltamivir and peramivir, but susceptible to zanamivir.

Baloxavir marboxil (baloxavir) is an investigational antiviral with a novel mechanism of action that targets the influenza polymerase complex. Baloxavir is a small-molecule prodrug of the selective polymerase acidic protein inhibitor S-033447 and has activity against influenzas A and B, including strains with neuraminidase inhibitor resistance. Results of a phase 2 dose-escalating study and a phase 3 placebo and active control trial were recently published.

Read more about baloixavir marboxil.

#2: Zimbabwe Declares State of Emergency Amid Cholera Outbreak

The Ministry of Health and Child Care of Zimbabwe has declared a state of emergency in the African nation as cholera infections are suspected in thousands of citizens.

The outbreak was first declared on September 6, 2018, in the capital city of Harare, according to the World Health Organization (WHO) Regional Office for Africa’s Weekly Bulletin on Outbreaks and Emergencies.

Harare is home to over 2 million individuals and epidemiological links to Harare have been confirmed in 5 additional provinces in Zimbabwe. The epicenter of the outbreak is in the Glenview suburb of the city which is an active trading area with a highly mobile population. The area is particularly vulnerable due to a lack of safely piped drinking water which has led to the use of borehole and wells.

Read more about the cholera outbreak in Zimbabwe.

#1: FDA Announces New Plan to Fight Antimicrobial Resistance

The US Food and Drug Administration (FDA) declared war on antimicrobial resistance (AMR) on September 14, announcing a comprehensive plan to combat arguably the biggest public health challenge facing the country.

By now, of course, everyone working within the field of infectious diseases knows the much-discussed figures provided by the US Centers for Disease Control and Prevention (CDC). Those numbers suggest that some 2 million Americans fall ill annually as a result of infections caused by antimicrobial-resistant pathogens; an estimated 23,000 of them die.

FDA commissioner Scott Gottlieb, MD, is hardly sanguine about reducing these numbers in the short-term, but he believes he and his colleagues within the FDA understand the best pathway forward.

“You’re all here today because you understand the importance of addressing antimicrobial resistance to maintain and advance the tools of modern medicine,” he told an audience gathered at the Pew Charitable Trusts in Washington, DC, for the agency’s announcement. “Not only for this generation, but for many generations to come. We can’t count on outracing drug resistance. But we can use stewardship and science to slow its pace and reduce its impact on human and animal health. To do so, we need an all-hands-on-deck approach to combating AMR in both human and veterinary settings. We need an all-of-the-above strategy.”

In presenting its 2019 Strategic Approach for Combating AMR, the FDA appears to be offering a 3-tiered strategy—one that starts with somewhat novel approaches for stimulating new antimicrobial development. Although Dr. Gottlieb lauded the accomplishments of “push”-style incentive programs such as the Generating New Antibiotics Now (GAIN) Act and the Limited Population Pathway for Antibacterial and Antifungal Drugs (LPAD) in generating new drug research and development, he noted that in spite of these efforts only 11 antibiotic products that are designed to address the most-threatening pathogens, as identified by the World Health Organization, are currently in clinical trials. He thus advocated for stronger “pull” incentives, including the creation of a new reimbursement model that would use milestone payments and subscription fees for new FDA-approved antibiotics with demonstrable clinical and social value—including those that tackle resistant pathogens.

Read more about the FDA’s plan to fight antimicrobial resistance.