Ebola Outbreak Updates: Virus Caused by New Strain, a Look Inside an Isolation Ward, and How the Virus Spreads

The Ebola virus that has killed more than 120 people so far this year in West Africa is a new strain, scientists say.

This is evidence that the disease did not spread from outbreaks in other regions of the country.

Dr. Stephan Gunther of the Bernhard Nocht Institute for Tropical Medicine in Hamburg, Germany, and his international team of researchers studied the genetics of the virus. Their  findings were reported online Wednesday in the New England Journal of Medicine.

The researchers said the novel strain probably evolved locally and circulated for months before being recognized.

The suspected first case of this outbreak was a 2-year-old child who died on December 6, 2013.

Ebola virus carries a fatality rate of 30 to 90%, depending on the strain. This particular outbreak caused death in 86% of confirmed cases (12 out of 14 patients died).

Here are some key findings from the study:

• The epidemiologic links between the cases suggest a single introduction of the virus into the human population, which seems to have occurred in early December 2013 or perhaps before.
• The assumed animal source of the outbreak has not yet been identified (but is possibly fruit bats).
• The length of exposure appears to have allowed many transmission chains, which led to an increased number of cases.
• Initial cases presented with fever, vomiting, and severe diarrhea. Hemorrhage, a common symptom of Ebola viruses that can help with early diagnosis, was not documented in early cases (although it may have developed later in those patients).
• The case fatality rate was 86% among the early confirmed cases and 71% among clinically suspected cases, which is consistent with the case fatality rates observed in previous Ebola virus disease outbreaks.

The World Health Organization (WHO) is providing daily updates on the outbreak. This report is from this morning:

In Guinea:

As of 18:00 on 16 April, the Ministry of Health (MOH) of Guinea has reported a cumulative total of 197 clinical cases of Ebola Virus Disease (EVD), including 122 deaths. To date, 101 cases have been laboratory confirmed, including 56 deaths, 43 cases (33 deaths) meet the probable case definition for EVD and 53 cases (33 deaths) are classified as suspected cases. Twenty-four (24) health-care workers (HCW) have been affected with 13 deaths.

A total of 36 patients are currently in isolation.

Numbers of cases and contacts remain subject to change due to consolidation of cases, contact and laboratory data, enhanced surveillance and contact tracing activities and the continuing laboratory investigations.

In Liberia:

As of 16 April the Ministry of Health and Social Welfare (MOHSW) of Liberia has reported a cumulative total of 27 clinical cases of EVD, including 13 deaths attributed to EVD. One new suspected case reported yesterday from Nimba County has been laboratory confirmed as a case of Lassa fever. Two patients remain hospitalised and 33 contacts remain under medical observation.

As of April 15, the health ministry in Guinea expressed optimism that the outbreak is almost under control because the death rate is slowing. Rafi Diallo, a spokesman for Guinea’s health ministry, said the new cases being monitored were all people who had been in contact with those who had fallen ill but were not themselves unwell.

“Once we no longer have any new cases … we can say that it is totally under control,” Diallo said.

Earlier this month, the WHO said the outbreak, which is one of the most challenging it has ever faced, would take two to four months to contain.

Dr. Sanjay Gupta visited an Ebola isolation ward in Guinea. Here is his report, from CNN:

The WHO explains how Ebola viruses are transmitted:

Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals. In Africa, infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest.

Ebola then spreads in the community through human-to-human transmission, with infection resulting from direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and indirect contact with environments contaminated with such fluids. Burial ceremonies in which mourners have direct contact with the body of the deceased person can also play a role in the transmission of Ebola. Men who have recovered from the disease can still transmit the virus through their semen for up to 7 weeks after recovery from illness.

The incubation period – the period of time from infection to presence of symptoms – can be between 2 – 21 days. The virus can be spread anytime during that period.

Spread of Ebola viruses via airborne particles has not been documented in among humans in “real world” settings, but that doesn’t mean it could never happen: Ebola viruses have been shown to have the ability to spread that way in research conditions. The Ebola-Reston subtype of the virus appeared in a primate research facility in Virginia, where it appears that transmission of Ebola from monkey to monkey occurred through the air. Ebola-Reston can infect humans, but does not cause illness in them.

So, what are the odds that the deadly pathogen could make its way to the United States?

The Wrap asked Dr. Gupta that very question, and here’s what he said:

In certain outbreaks it kills 9 out of 10 people infected. It does make people nervous — I think what’s particularly worrisome about this is that it has always been in remote African forests, and we didn’t worry about it spreading because the grim reality is that it would kill people so fast that it wouldn’t spread. The problem now is that it is in Conakry [capital of Guinea], which is a city of 2 million and has an international airport and the possibility of someone getting on a plane who has been exposed but not developed any symptoms, that’s a real concern. It’s not likely to happen, but it has been keeping people up at night.

SurvivalBlog.com has compiled information on implications of an Ebola outbreak and prepping tips in the article Ebola for Beginners.

To date, the deadly Ebola virus has not reached the United States, but to believe that it never could is naive. It certainly can’t hurt to be prepared in case that day comes.

For more information on Ebola viruses, watch this fascinating and informative NOVA documentary, Ebola: The Plague Fighters: