May 2021

Emerging Infectious Diseases Journal

Highlights: Emerging Infectious Diseases, Vol. 27, No. 5, May 2021

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The articles of interest summarized below will appear in the May 2021 issue of Emerging Infectious Diseases, CDC’s monthly peer-reviewed public health journal. This issue will feature Emerging Viruses. The articles are embargoed until April 14, 2021, at 12 p.m. EDT.

1.    Global Trends in Norovirus Genotype Distribution among Children with Acute Gastroenteritis, Jennifer L. Cannon et al.

Noroviruses are a leading cause of acute gastroenteritis among adults and children worldwide. The burden is highest among children younger than 5 years of age, who are most at risk for severe illness, prolonged symptoms, and infection with multiple strains, contributing to community transmission and outbreaks among all age groups. Thus, young children in this age group would probably benefit most from norovirus vaccines and are a critical group for evaluating future vaccine effectiveness. During 2016–2020, NoroSurv, a global pediatric norovirus surveillance network that monitors strains affecting young children, detected 22 different norovirus genotypes reflecting the high diversity among noroviruses.  Surveillance data captured in NoroSurv allow monitoring trends in norovirus strains associated with childhood acute gastroenteritis throughout the world on a near real-time basis, supporting the development of pediatric norovirus vaccines.

Contact: CDC Media Relations, phone: (404) 639-3286 or email:

2.   Case Series of Laboratory-Associated Zika Virus Disease, United States, 2016–2019, Susan L. Hills et al.

The use of Zika virus in laboratory research and diagnostic testing increased considerably after Zika virus began spreading through the Americas in 2015, increasing the risk for potential Zika virus exposure of laboratory workers and biomedical researchers. During 2016–2019, a total of 4 cases of laboratory-acquired Zika virus infection were reported in the United States, including 2 associated with needlestick injuries and 2 in which the means of exposure was undetermined. Although Zika virus transmission has declined substantially in recent years, research using Zika virus is ongoing. Exposure and infection are occupational risks for laboratory and biomedical research workers who work with live virus. Establishing and implementing appropriate policies and procedures, providing adequate training, making available and ensuring proper use of personal protective equipment and other safety equipment, and confirming that facilities are suitable for the type of work being conducted are all required to reduce the risk for Zika virus exposure and disease among laboratory personnel.

Contact: CDC Media Relations, phone: (404) 639-3286 or email:

3.    Coordinated Response to Imported Vaccine-Derived Poliovirus Infection, Barcelona, Spain, 2019–2020, Dolores Álamo-Junquera et al.

Although the oral polio vaccine (OPV) chosen for the global polio eradication initiative (GPEI) is safe for people with functioning immune systems, OPV and other live vaccines are not recommended for people with immune deficiencies, who are susceptible to vaccine-associated paralytic polio infection and can pose a risk to other persons, potentially jeopardizing the success of polio-eradication efforts. In 2016, the transition to using inactivated polio vaccine instead of OPV for routine childhood vaccination, proposed by the GPEI, was begun. In May 2019, public health officials in Barcelona, Spain, were notified about a poliovirus infection in an asymptomatic person with an immune deficiency. The infection was detected through ongoing nonpolio enterovirus surveillance at a hospital in Barcelona. Born in Pakistan, the 26-year-old patient had lived in Barcelona since 2010 and had been vaccinated as a child in Pakistan with what was probably OPV. The subsequent investigation brought together all the healthcare professionals involved in the patient’s follow-up. Like wild polioviruses, OPV-derived polioviruses are excreted through the gastrointestinal tract, and because persons with immunodeficiency-related vaccine-derived poliovirus infection can maintain prolonged excretions while remaining asymptomatic, community exposure was a concern. Contact tracing extended beyond family members and included work contacts at a restaurant where the patient worked as a cook as well as healthcare personnel and other patients at the hospital. A total of 59 persons who were potentially exposed were vaccinated with inactivated poliovirus vaccine as a result. The case-patient was treated with the antiviral drug pocapavir, which is being considered for use in poliovirus-excreting patients with immune deficiencies on a compassionate-use basis. In certified polio-free countries like Spain, disease surveillance guidelines must address asymptomatic poliovirus carriers and the need for screening people who have immune deficiencies.

Contact: Communications Officer of the Agencia de Salut Pública de Barcelona, Beatriz Román (, and Epidemiology Director, Cristina Rius (



Page last reviewed: April 12, 2021