Over the weekend, the World Health Organization released a disease outbreak report on the events surrounding the death of a Russian infectious disease researcher earlier this month, highlighting that Russia has yet to report a confirmed cause of death. With that “key uncertainty,” the United Nations health agency said it remains impossible to assess the risk of the event or whether the public health measures Russia took were adequate to prevent spread of the unknown disease.
The WHO reported that, so far, it has seen no evidence of ongoing transmission of the mystery disease. “However, confidence in the assessment remains limited by the absence of a confirmed etiological diagnosis, and the remaining uncertainty regarding the source and mode of exposure,” the agency wrote in its report.
The agency laid out the order of events as information trickled out from Russian authorities, noting that it only became aware of the death via media reports on October 2. The WHO subsequently made contact with Russian authorities and requested information on October 3, 6, 7, and 8.
Limited information released
Early media reports indicated that the lab worker had become ill on September 29, possibly following an incident at the lab, the Irkutsk Antiplague Research Institute (APRI) of Siberia and the Far East. Some early reports suggested that the researcher—who was identified by media as 28-year-old Darya Shipilova—died of the plague after breaking a test tube.
On October 2, the Irkutsk branch of Russian health agency Rospotrebnadzor (RPN) said in a statement that a “special sanitary-epidemiological expert commission” had already met over a suspected case of a high-threat pathogen. Sanitary and epidemic control measures were put in place, including identifying, monitoring, and testing all contacts. At the time, RPN said that all contacts had tested negative for high-threat pathogens.
On October 6, Russia’s National Focal Point for the International Health Regulations (NFP) first responded to the WHO’s information requests, saying that no case of plague had been recorded in Irkutsk Oblast. The NFP confirmed that an APRI lab worker had died from a severe case of pneumonia after developing symptoms compatible with an acute respiratory viral infection. The worker was tested for a number of high-threat pathogens, but all the tests had come back negative. Doctors categorized the cause of death as being from pneumonia of undetermined etiology.
The NFP also reiterated information from RPN about the public health measures taken and that people in contact with the lab worker all tested negative for high-threat pathogens. The NFP added that the widest range of possible contacts were identified and tested in accordance with Russia’s public health laws.
Uncertain risk
In follow-up responses, the NFP gave more details about testing and some results that weren’t concerning. It said authorities conducted 5,500 laboratory tests on contacts. They tested for a range of pathogens, including influenza, SARS-CoV-2, other respiratory infections, and bacterial infections, including plague and Streptococcus. Among the contacts, they identified two cases of COVID-19, three cases of rhinovirus, and one case of Haemophilus spp., a common bacteria group that includes those that can cause respiratory infections and pneumonia. They also found a few opportunistic infections.
As of October 9, Russian authorities told WHO that they had not detected any high-threat pathogens in the laboratory’s research portfolio in any of the contacts, and they were no longer being monitored. The monitoring period was set for seven days for all the contacts.
Authorities also added that the worker who died was not infected with plague bacteria, Yersinia pestis, and the worker had been vaccinated against the infection due to the occupational hazard. They added that no lab biosafety or biosecurity incident had occurred at APRI, and the deceased worker had not traveled outside the region within the two weeks before becoming ill.
Reviewing all the information coming out of Russia, the WHO was largely at a loss as to what happened and what risk the event posed, concluding: “A key uncertainty for this event is the absence of a confirmed diagnosis in the deceased laboratory worker.” Without the cause of death, the agency can’t “independently assess whether the duration of the reported monitoring period for contacts was sufficient to exclude all plausible causes of the fatal illness.” They also aren’t ruling out the possibility of a laboratory-associated exposure.
