Several people who came into contact with a woman who died of pneumonia of unknown etiology in Russia’s Irkutsk Region have tested positive for COVID-19 and rhinovirus, the country’s sanitary watchdog said.“Laboratory tests have confirmed two COVID-19 and two rhinovirus infection cases,” Rospotrebnadzor said, adding that no other infectious disease pathogens were detected among the contacts, according to Russia’s TASS news agency.The development comes amid reports that the woman, a researcher at an anti-plague institute in Siberia, may have been exposed to Yersinia pestis, the bacterium that causes plague. Russian authorities have not confirmed plague as the cause of her illness or death.What Happened in Russia?The researcher was identified by Russian reports as 28-year-old Darya Shipilova, who worked at the Irkutsk Anti-Plague Research Institute.Russian media initially reported that Shipilova had broken a test tube containing plague bacteria in late September, subsequently developed severe pneumonia and died.However, Rospotrebnadzor said her diagnosis was “pneumonia of unknown etiology.” Expanded testing did not identify microorganisms associated with her professional activities.The World Health Organization said Shipilova died of severe pneumonia overnight into October 2 and that the cause of death had not been confirmed, The CBS News Report said.Nearly 200 people who may have had contact with her have reportedly been placed under medical observation.Rospotrebnadzor said the sanitary and epidemiological situation in Irkutsk and Shelekhov remained stable and that special measures had been implemented following her death.Kremlin spokesman Dmitry Peskov stressed that Rospotrebnadzor was the lead agency with expertise in the matter and urged Russians to follow information from its “highly qualified professionals”, media reports said.Trump Offers US HelpUS President Donald Trump has offered to help Russia after a laboratory worker died following an illness at an anti-plague research institute in Siberia, amid reports of a suspected pneumonic plague case.Russian authorities, however, have said the situation is under control and have not confirmed plague.“We’ll help,” Trump told reporters at the White House. “Everybody who has that kind of a problem, we’ll always help”.Describing the plague as a “rough disease,” Trump said he had not spoken to Russian officials about the case but that the US would do what it could to help.“That’s a disease we used to be able to control,” Trump said, adding that “somehow those microbes have gotten stronger and stronger, they’re like an army.”“They called it pneumonia, and pneumonia, you know, years ago, you could treat pneumonia easier. The microbes and the germs have gotten stronger disproportionately. But we’ll help them, we’ll help them,” Trump said.US, EU Monitor SituationThe US State Department said it was monitoring the reports with the CDC and other agencies.CDC officials said plague is a known and treatable disease, with antibiotics particularly effective when treatment begins early. Secretary of State Marco Rubio said the situation was “not cause for alarm” but warranted continued monitoring.The European Commission said it was “monitoring very closely” the reports and was in contact with the European Centre for Disease Prevention and Control.WHO Says Public Risk Is LowThe World Health Organization said testing was underway and the cause of death had not been confirmed.The WHO said it was in contact with Russian authorities and had offered support if needed. Based on available information, it assessed the risk to the general public as low.What Is Pneumonic Plague?Plague is caused by Yersinia pestis, a bacterium generally found in small mammals and their fleas.The same bacterium caused the Black Death, which swept across Europe in the 14th century and killed an estimated 25 million to 50 million people.Plague can occur in several forms. Bubonic plague primarily affects the lymph nodes, while pneumonic plague affects the lungs and is the form most capable of spreading directly between people.Pneumonic plague can become rapidly life-threatening without treatment but is treatable with antibiotics when diagnosed and treated promptly.