A new type of Ebola fever in Uganda might be less deadly than others — but that’s not necessarily good news.
The World Health Organisation (WHO) said last week that an ongoing Ebola outbreak in Uganda was caused by a new subtype, the fifth to be detected since the virus was first identified in 1976 in Sudan and the Congo. While information about the outbreak was still limited, it appeared to be killing fewer of its victims than other strains typically do.
Dr Tom Ksiazek, chief of the special pathogens branch at the United States’s Centres for Disease Control and Prevention (CDC), said on Wednesday it was premature to conclude whether the new Ebola strain was milder.
If it were, its victims could be less contagious, Ksiazek said.
A less lethal version of Ebola, though, might spread unnoticed and be confused with other diseases, making it ”a more difficult challenge”, said Asiya Odugleh-Kolev, a WHO communications expert who has worked on numerous Ebola outbreaks.
Ending previous Ebola outbreaks in Africa has largely depended on Odugleh-Kolev’s specialty: teaching people to spot the disease early and to reduce behaviour that could spread it. She said people might not take a less dangerous form of Ebola seriously, or fail to take the proper precautions because they think they have measles or some other disease.
The new type of Ebola has so far killed at least 18 people in Uganda. On Tuesday, officials at Uganda’s Ministry of Health said there were 75 suspected cases in Bundibugyo district in western Uganda.
Typically, Ebola kills between 50% and 90% of the people it infects.
Two teams of international experts, including infection-control doctors, have been sent by the CDC and the WHO to help local officials contain the virus.
Ugandan officials report that some health workers have fled the outbreak’s epicentre in fear and that there is a staff shortage.
Ebola causes fever, intense weakness, muscle pain and other symptoms. In severe cases, the virus damages the kidneys and liver, and patients may bleed internally and externally. Ebola is usually spread by close contact with an infected patient, or by contact with the secretions of an infected patient.
In Uganda, the WHO said the classic Ebola symptoms were not always present, and that in the current outbreak, there were more reports of vomiting than usual. That slowed diagnosis, according to Ugandan health authorities who said that the outbreak might have begun in August.
The Ebola viruses from Uganda examined so far appear to be up to 25% different genetically from previously known Ebola strains.
Ksiazek was unsure whether this difference might be significant for patients and doctors. ”What we know from previous Ebola outbreaks is still going to apply,” he said. ”We now have to figure out if the mortality might be any different.”
Doctors also worry that the presence of other diseases in Uganda could complicate the effort to contain Ebola. Because the symptoms for diseases such as malaria and typhoid are sometimes similar to those for Ebola, doctors and nurses will need to be careful not to mix Ebola patients with other patients, which could spread the virus in healthcare centres.
The last outbreak of Ebola in Uganda occurred in October 2000 when 173 people died and 426 people were infected in the north of the country. — Sapa-AP