November 2021

Emerging Infectious Diseases Journal

Highlights: Emerging Infectious Diseases, Vol. 27, No. 11, November 2021

The articles of interest summarized below will appear in the November 2021 issue of Emerging Infectious Diseases, CDC’s monthly peer-reviewed public health journal. This issue will feature respiratory infections. The articles are embargoed until October 13, 2021, at noon Eastern time.

Important Note: Most articles that EID publishes do not represent work done at CDC or by CDC staff. In your stories, please use our suggested language to clarify whether a study was conducted by CDC (“a CDC study”) or by another institution (“a study published by ____ 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.

Please link directly to the actual journal article in your stories. Once the embargo lifts, this month’s articles will be found in the Early Release section of the EID website.

EID is publishing many articles on the COVID-19 pandemic. Because we publish those articles on an expedited track, and we have no embargo on their content, we do not include them in these monthly press notices. You may wish to subscribe to receive email notifications when EID publishes expedited articles as well as other types of articles.

Note that the most recent EID COVID-19 papers are at the top of the journal’s home page and also included in the Coronavirus Spotlight.

1. Ehrlichiosis and Anaplasmosis among Transfusion and Transplant Recipients in the United States, Sanjida J. Mowla et al.

The organisms that cause ehrlichiosis and anaplasmosis are known to be transmitted by ticks, but they can also be transmitted by transfused blood or transplanted organs. Early detection and treatment of these infections in people receiving blood transfusions or organ transplants can prevent severe illness and death. Since 2000, the risk to transfusion and transplant recipients has increased substantially. However, because these infections remain relatively rare and symptoms (such as fever) are common to other illnesses, their diagnosis and treatment in recipients might be missed. A literature review of ehrlichiosis and anaplasmosis cases among transfusion and solid organ transplant recipients identified 132 cases during 1997–2020, of which 12 were confirmed to be transmitted by transfusion and 8 by solid organ transplant. An additional 13 cases were likely donor-derived from solid organ transplant based on time of infection, but confirmatory evidence is not available. The remaining 99 cases developed illness more than a year following solid organ transplant and are unlikely to have resulted from transplanted organs. Routine laboratory screening of organ donors does not yet include testing for Ehrlichia and Anaplasma species. However, as prevalence of tickborne disease infections rises, additional interventions to reduce risk such as laboratory screenings are needed to enhance blood and organ safety. In addition, clinicians should closely monitor blood and solid organ recipients during follow-up and consider Ehrlichia and Anaplasma as potential causes of signs or symptoms of infection.

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

2. Acute Chagas Disease Manifesting as Orbital Cellulitis, Texas, USA, F. Parker Hudson et al.

Infection with the Trypanosoma cruzi parasite, or Chagas disease, is common in Latin America. An estimated >300,000 cases of chronic Chagas disease in the United States exist among immigrants, most of whom acquired infection through vector-borne transmission from insects of the triatomine subfamily (conenose bugs or kissing bugs) before traveling from a Chagas disease–endemic area. However, local cases of vector-borne Chagas transmission to humans in the United States is very rare (a 2009 study identified only 7 acute cases since 1955). Most people with acute Chagas have no symptoms, but some may have symptoms, including what is known as Romaña’s sign, a painless inflammation around the eyes attributed to triatomine feces deposited or inadvertently rubbed into the eyes. Researchers evaluated a recent case of locally-acquired, vector-borne, acute Chagas disease in a patient in central Texas who exhibited Romaña’s sign, which doctors initially mistook for orbital cellulitis (a bacterial infection of the eye). The patient had persistent ocular symptoms and fever despite receiving broad-spectrum antibiotics and an extensive diagnostic workup. Next-generation genetic sequencing was extremely useful for finally identifying the cause, and the patient’s condition resolved rapidly once he was prescribed an appropriate anti-parasitic drug. Physicians in the United States should be aware of the risk for vector-borne transmission of Chagas in and around residential areas, particularly in southern areas such as Texas. Prompt recognition and treatment of acute Chagas disease can lead to cure and prevent unnecessary hospitalizations as well as illness and death associated with chronic Chagas disease.

Contact: Shahreen Abedin, Director Media Relations, Dell Medical School UT Austin,

3. Encephalitis and Death in Wild Mammals at a Rehabilitation Center after Infection with Highly Pathogenic Avian Influenza A(H5N8) Virus, United Kingdom, Tobias Floyd et al.

In late 2020, a disease outbreak caused the deaths of swans, seals, and a fox at a wildlife rehabilitation center in the United Kingdom. Five swans died after onset of highly pathogenic avian influenza virus infection while they were in captivity, soon after which 3 seals and a fox also succumbed. Researchers later determined that avian-origin influenza A virus subtype H5N8 was the cause, that the swans were most likely the source of infection for the fox and seals, and that virus transmission probably occurred by transfer onto physical objects (fomite transmission) or through the air (aerosol transmission). Live virus isolated from the swans, seals, and the fox showed a single genetic change, and this change may have been the potential adaptive mutation that enabled the avian virus to “spill over” and infect the mammalian species at the facility. A question that remains is why infection with an H5N8 isolate of avian influenza, which is pathogenic for birds, caused death  in mammals in this incident. Although genetic analyses indicated no increased risk for human infection with the H5N8 viruses in this outbreak and no human influenza-like illness was reported in the weeks after the event, this episode demonstrates how these viruses can have unexpected and severe health risks for mammals. A “spillover” event like this one, in which a virus spreads from a typical host species into an atypical host species, is something for veterinary authorities to consider during disease outbreaks and highlights the importance of wildlife disease surveillance that uses interdisciplinary and collaborative approaches.

Contact: APHA Press office:


Page last reviewed: October 13, 2021