Ebola resurfaces in Uganda--history and analyses of Ugandan Ebola

Uganda just can't catch a break. They've recently been hit with nodding disease, a mysterious syndrome where children repeatedly nod their heads and undergo serious seizures, typically leading to death. Now they're in the grips of another Ebola outbreak. This will be the fourth time the country has suffered through Ebola since 2000, when the virus was first found in the country:

The first occurred in August of 2000; the first case died in Gulu on the 17th of September. Despite an investigation, doctors were unable to determine where or how she had contracted the disease. Her death was followed by the deaths of her husband, two children, and several other family members. This was reported to the Ministry of Health in October of that year, near the peak of the epidemic. An investigation and intervention to control the disease followed, and the epidemic was declared to be over in January of 2001. A total of 425 patients from 3 villages (Gulu, Masindi, and Mbarara) across Uganda were identified based on symptoms and/or laboratory data. 224 of them died, with a resulting mortality rate of 53%; an eerie echo of the 1976 Ebola outbreak in Sudan. Indeed, sequence analysis showed the infecting strain to be the Sudan subtype of Ebola; the first time this type had surfaced since the 1979 outbreak in Sudan. It is hypothesized that Sudanese rebels, who carried out regular attacks around Gulu, may have accidentally introduced the virus in some manner, though this has not been confirmed.

Ebola returned to Uganda in August of 2007, causing 149 illnesses and 37 deaths until the outbreak was declared over in February of 2008. This mortality (36%) was significantly lower than most Ebola outbreaks. Interestingly, when scientists tested this virus, it also reacted strangely with their assays. Therefore, they determined the entire molecular sequence of the virus, and found that it was a whole new strain of Ebola, which they named Ebola Bundibugyo.

The third outbreak occurred just last year, as a single case in a 12-year-old girl, who died of the infection. I've not been able to find any follow-up identifying the 2011 strain, but Uganda has been hit previously by both the Sudan and the novel Bundibugyo strains of Ebola, and the current outbreak has been identified once again as Ebola Sudan.

In the current outbreak, which began in the Kibaale district in western-central Uganda, at least 20 have been affected and 14 have died. As of today, an additional six cases are suspected but not yet confirmed, and it appears to be affecting more than one village in the district. One death has also occurred at Mulago hospital in the capital of Kampala. The individual who died was reported to be:

... a health worker who "had attended to the dead at Kagadi hospital" in Kibale, Health Minister Christine Ondoa told reporters.

She is believed to have travelled independently to Kampala -- possibly on public transport -- after her three-month old baby died, Ondoa added.

Reports also note that other health care workers are in quarantine as a precaution. In Africa, Ebola has really been able to spread in previous outbreaks for two reasons: breakdowns in barrier nursing within hospitals (not wearing gloves/gowns; reusing needles; lack of handwashing/sanitation, etc.) and ritual funeral practices within villages, which put many family members in contact with the virus as they assist with cleansing the victim. Indeed, it appears that 9 of the deaths in this outbreak have come from a single family, so it's quite possible many were sickened using this type of practice. However, now that Ebola has been confirmed and people are aware of this, stricter controls over these practices can be implemented, and health care workers are being urged to report any cases that may be Ebola to authorities.

Kampala is a city of a bit over a million people on Lake Victoria, southeast of the Kibaale district. The 2011 case originated from Luwero district, due east of the Kibaale district and north of Kampala. The 2000 outbreak occurred in the Gulu district in the north of the country, and the 2007 outbreak in the Bundibugyo district, in the west and neighboring Kibaale. It would seem that Ebola reservoirs (likely fruit bats) could very well be spread across Uganda's central region, occasionally spilling over into the human populations and igniting these outbreaks. One story notes that "The site where most of the cases occurred are close to Kibale forest where there are a lot of monkeys and birdlife," and while bats are not explicitly mentioned, they presumably would also be present. Non-human primates have also been implicated in previous outbreaks of Ebola as an amplifying species.

The reporting of the current outbreak was delayed, as patients didn't have any noticeable bleeding--rather, diarrhea and vomiting were the main reported symptoms. However, while many reports I've seen are characterizing hemorrhagic symptoms as "typical," these aren't seen in all patients, and indeed the diarrhea, vomiting, and even hiccups are common symptoms of Ebola infection. As such, Uganda has been playing a bit of catch-up, but has certainly learned since the first (and worst) outbreak in 2000. Hopefully this one will end fairly quickly.

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Wouldn't a less virulent strain of Ebola be bad news? So far the outbreaks have been devastatingly intense, wiping out village rapidly but without much spread as the sick are too ill to travel. A 20% mortality Ebola hitting the slums of Kampala sounds like the recipe for a horrible epidemic.

Well, Bundibugyo mortality was only 36% in its outbreak, and of course the Reston strain is 0% in humans. And even of those who lived in the Bundibugyo outbreak, they still were pretty damn sick--they just recovered. So it's really the morbidity (how sick people get) rather than the mortality (death) that makes the difference, and I've not seen great stats on how morbidity/course of disease differs between the African Ebola strains.

Point of correction, Kampala is a capital city situated in Central Uganda, on Lake Victoria, with a population of at least two million people. The person died in the National Referral Hospital Mulago, and this is a real scare because of the number of patients and medical staff who could have been in contact with the deceased.

By Nada Andersen (not verified) on 30 Jul 2012 #permalink

Thanks--looking around, I see it cited anywhere from a bit over a million up to 2.5 million. The CIA factbook put it at 1.5M in 2009 (source) so that's where the number came from.

@Tara C.Smith
am I dreaming or you are talking about mortality saying ...was ONLY 36%...
It's about human dying and not laboratory survival rate experiment.
Respect please

It's relative. 36% is much better than the 85 or 90% mortality we see with the Zaire strain of Ebola, or even the 50-60% we typically see with the Sudan strain. In any case, I didn't say "only 36%," I simply quoted the final rate for that particular outbreak. I'm well aware these are human lives lost, including children in many cases, and that every outbreak is tragic.

Thank you for making it clear. it gathers basic knowledge one need on Ebola. I'm just wondering if the outbreak could not have any relation with rebels fighting in the region (in DRC though, but it's close to Kibaale).
Thanks again.

Epidemiological report is factual,comparison of vital statistics is for planning purpose and we must adhere to.Nothing curative for Ebola apart from preventive measures.South Sudan is preparing for the killer through quarantine measures as for the areas with Uganda.

By LUBANG DAVID L… (not verified) on 08 Aug 2012 #permalink

i personally lost repents as result of Ebola out break in Uganda Kikyo parish Ngamba sub county. lack of laboratory to test out break of new diseases in rural area lead to spread Ebola and killed many people at Kikyo health cent re 4.it to time to known the disease not until samples were taken to south Africa for test.for more information about Ebola Bundibugyo conduct me.

By kalemire milton (not verified) on 09 Jan 2015 #permalink