November 2020

Emerging Infectious Diseases Journal

Highlights: Emerging Infectious Diseases, Vol. 26, No. 11, November 2020

Important Note: Not all articles that EID publishes represent work done at CDC or by CDC staff. In your stories, please clarify whether a study was conducted by CDC (“a CDC study”) or by another institution (“a study published by CDC in the EID journal”). Opinions expressed by authors contributing to EID do not necessarily reflect the opinions of CDC or the institutions with which the authors are affiliated. EID requests that, when possible, you include a live link to the actual journal article in your stories. Once the embargo lifts, this month’s articles will be found in the Ahead of Print section of the EID website at

The articles of interest summarized below will appear in the October 2020 issue of Emerging Infectious Diseases, CDC’s monthly peer-reviewed public health journal. This issue will feature Emerging Viruses. The articles are embargoed until October 14, 2020, at 12 p.m. EDT.

1.     Preventing Vector-Borne Transmission of Zika Virus Infection During Pregnancy, Puerto Rico, USA, 2016–2017, K. Kortsmit et al.

Zika virus is spread by the bite of infected Aedes species mosquitoes (Ae. aegypti and Ae. albopictus). For pregnant women who are infected, Zika virus may cause serious birth defects in their newborn infants. During an outbreak of Zika virus infection in Puerto Rico during 2016–2017, the U.S. CDC and the Puerto Rico Department of Health published guidelines on how to prevent infection. These guidelines include recommendations that pregnant women prevent mosquito bites by wearing protective clothing (such as long-sleeved shirts and long pants) and using insect repellent. To determine whether pregnant women were counseled to follow these guidelines, researchers surveyed women in Puerto Rico who had recently given birth. Most women reported receiving provider counseling about these practices during prenatal care visits, and provider counseling was associated with using insect repellent but not wearing protective clothing. The most common reason given for not wearing protective clothing during pregnancy was because it was too hot. Findings from this study may apply to other diseases spread by mosquitoes, such as dengue, chikungunya, and malaria.

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

2.   High Dengue Burden and Circulation of 4 Virus Serotypes among Children with Undifferentiated Fever, Kenya, 2014–2017, M. M. Shah et al.

Dengue is a disease that can cause mild symptoms, such as fever, or it can be severe and fatal. There are four types (also known as serotypes) of the virus, which is spread by mosquitoes. In Kenya, dengue is a common cause of fever in children. To learn how often dengue (as opposed to other diseases such as malaria) is the cause of fever in children and which dengue types are responsible, during 2014–2017, researchers tested blood samples of 1,022 children in Kenya who were ill with fever. They found that a surprisingly high proportion of these children (41.9%) were infected with dengue virus, and among the samples, they detected all four types of the virus. Genetic testing of the viruses indicated that some strains were not typically found in Africa, which indicates that the infecting viruses may have been imported by people traveling to Africa from other continents. Because of wrong diagnoses, many of these children may have received antimalarial drugs or antibiotics, which can lead to unnecessary side effects or antibiotic resistance. Specific testing for dengue that can be performed in outpatient settings is needed but not yet available. Meanwhile, dengue activity will probably continue to spread in Africa because of rapidly changing land use, climate change, urbanization, increased human travel, and international trade.

Contact: Melisa M. Shah, Stanford University, phone: 478-972-7367 or email:

3.     Nowcasting (Short-Term Forecasting) of Influenza Epidemics in Local Settings, Sweden, 2008–2019, Armin Spreco et al.

Public health officials and healthcare providers who have reliable forecasts of when and where an influenza outbreak will occur can launch timely public health communication campaigns and implement rapid resource allocation in healthcare settings (for example, making sure hospitals have enough beds and intensive care units ready for a sudden surge in influenza patients). Different types of methods for forecasting influenza have been developed and applied to support public health responses, but the public health community has not always used them, possibly because national public health policies for responding to infectious disease outbreaks often assign the responsibility for healthcare resource allocation to local health authorities (i.e., county and municipality governments). The timing of the spread of influenza can differ substantially between these jurisdictions within nations and states. Consequently, a need exists for influenza forecasting that accounts for the policy-making responsibilities of local governments and is more timely and relevant for public health decision-makers at the local level. Researchers from Sweden and CDC conducted a 10-year evaluation of a local influenza nowcasting (short-term forecasting) method in three urban counties in Sweden, each with their own independent public health administrations, by using routine health information system data. They nowcasted when seasonal and pandemic influenza outbreaks would start, when they would peak, and how intense the peaks would be. The seasonal influenza nowcasting method performed satisfactorily in all three urban counties as far as predicting the start and peak of an influenza outbreak. Predictions of the local peak intensity were satisfactory in two of the study counties, but they were poorer in one county, possibly because results were skewed by population mixing with a neighboring metropolitan area. The local nowcasting method can assist local healthcare planning during epidemics, giving them lead time to allocate resources so that all patients in the healthcare system can receive adequate care.

Contact: Toomas Timpka, Center for Health Services Development, Region Östergötland, Linköping, Sweden; email: or phone: +4613282798



Page last reviewed: October 13, 2020