June 2017
Emerging Infectious Diseases Journal
Highlights: Emerging Infectious Diseases, Vol. 23, No. 7, July 2017
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The articles of interest summarized below will appear in the July 2017 issue of Emerging Infectious Diseases, CDC’s monthly peer-reviewed public health journal. This issue will feature Emerging Viruses. The articles are embargoed until June 14, 2017, at 12 p.m. EDT.
1. Novel Retinal Lesion in Ebola Survivors, Sierra Leone, 2016, Paul J. Steptoe et al.
In West Africa, the largest outbreak of Ebola virus disease in history left just over 10,000 survivors; previous outbreaks left only dozens. The scale of this epidemic and its large number of survivors has facilitated research on the after-effects of Ebola (post-Ebola syndrome). It is known that the Ebola virus is capable of persisting in the eye even after recovery from the acute infection often causing severe inflammation and even cataracts in some survivors. However, little has been known about specific effects of the virus on the back of the eye and if cataract surgery is safe for survivors and surgeons.
In a recent study of the long-term effects of the Ebola virus on the eye, researchers working with Ebola survivors in Sierra Leone discovered a unique retinal scar specific to the disease. The location of the scars suggests that the virus can travel along the optic nerve to reach the eye. Fortunately, the scars appear to spare the central vision. Researchers also tested the eye fluid of two survivors with cataracts secondary to Ebola and found the virus had cleared from the eye fluid; this provides provisional evidence that cataract surgery can be attempted safely.
Contact: Paul J. Steptoe, University of Liverpool, Institute in the Park, Alder Hey Children’s Hospital, Eaton Rd, Liverpool, Merseyside, L12 2AP, United Kingdom; email: paul.steptoe@liverpool.ac.uk.
2. Phylogeography of Burkholderia pseudomallei Isolates, Western Hemisphere, Jay E. Gee et al.
Phylogeography is the study of relationships among living things and their location on Earth. In public health, phylogeography can be used to study the genetic relationships of bacteria and track the geographic origin of the illnesses they cause. One such illness is melioidosis, a severe and sometimes fatal disease caused by a bacterium called Burkholderia pseudomallei, which is mainly found in the soil and surface water in tropical regions. Melioidosis is often mistaken for other diseases at first, which can delay proper treatment and result in more severe illness. Although the full geographic distribution of B. pseudomallei is not known, previous studies indicated that the bacterium originated in Australia, moved to Southeast Asia, then to Africa and finally to the Western Hemisphere. To further characterize the bacterium within the Western Hemisphere, researchers recently studied a type of DNA variation, called a single-nucleotide polymorphism. For a melioidosis patient in the United States (where melioidosis is not common), this technique can be used to help determine where the infection was acquired (usually from travel to regions where melioidosis is common). This technique is particularly useful when the patient’s travel history is unknown or includes several potential source countries. As more examples of B. pseudomallei are collected from around the world and genetic data analyzed, the ability to identify the geographic origin of infections will continue to improve. An increased ability to determine probable sources of infection will allow public health authorities to more readily identify risks to people such as travelers and improve rapid diagnosis which will assist in administering proper treatment in a timely manner.
Contact: CDC Press Office, media@cdc.gov or 404-639-3286.
3. Measles Outbreak with Unique Virus Genotyping, Ontario, Canada, 2015, Shari Thomas et al.
Although measles has been eliminated in Canada and the United States, both countries continue to experience reintroductions of measles virus because of cases occurring in travelers from abroad. Researchers examined an unusual outbreak of measles that occurred in Ontario in early 2015. They noted that this outbreak consisted of cases with a unique strain of a genotype of the measles virus and that there was no known association among the primary case-patients (i.e., patients who did not contract measles from another case-patient). A total of 18 cases of measles were reported from 4 public health jurisdictions in the province during the outbreak period (January 25–March 23, 2015). Strikingly, none of those cases occurred in people who had recently traveled. Despite enhancements to case-patient interview methods and epidemiologic analyses, public health authorities never identified a source patient. However, the molecular epidemiologic analysis, which included extended sequencing, strongly suggested that all cases derived from a single importation of measles virus genotype D4. The use of timely genotype sequencing, rigorous epidemiologic investigation, and a better understanding of the gaps in surveillance are needed to ensure that Ontario’s measles elimination status is maintained.
Contact: Janet Wong, Public Health Ontario. janet.wong@oahpp.ca or 647-260-7709.
