Today, 9 May 2015, WHO declares Liberia free of Ebola virus transmission. Forty-two days have passed since the last laboratory-confirmed case was buried on 28 March 2015. The outbreak of Ebola virus disease in Liberia is over.
This is a huge improvement and major achievement for the nation. However, the threat of Ebola still persists as some neighboring countries still have cases being reported:
While WHO is confident that Liberia has interrupted transmission, outbreaks persist in neighbouring Guinea and Sierra Leone, creating a high risk that infected people may cross into Liberia over the region’s exceptionally porous borders.
The government is fully aware of the need to remain on high alert and has the experience, capacity, and support from international partners to do so. WHO will maintain an enhanced staff presence in Liberia until the end of the year as the response transitions from outbreak control, to vigilance for imported cases, to the recovery of essential health services.
The Americas have led the way when it comes to eradicating diseases. It was the first region in the world to eradicate smallpox in 1971 and then polio in 1994. And the PAHO (Pan American Health Organization) already has its sights on another target.
However, elimination of this virus, or others, does not mean people should stop vaccinating. It demonstrates the importance and effectiveness of vaccination.
The eradication of rubella doesn’t mean we’ll never see the virus again in the U.S. People still bring it here from other countries. But it doesn’t spread far because so many Americans are vaccinated.
Despite the success of vaccines in eradicating these harmful and lethal diseases, there is still more to do!
“With rubella under our belt, now it’s time to roll up our sleeves and finish the job of eliminating measles as well,” Etienne (director of PAHO) said.
I guess PAHO should start in California, hahahaha (not really funny). Who said vaccines are ineffective??? And what did they base that lie on??
A great piece by NPR. UNC (woohoo Tarheels!) researcher Ralph Baric had been investigating MERS (Middle East Respiratory Virus) until a recent government moratorium halting that kind of research.
If this virus mutates so that it spreads easily through the air, millions could die. “It would go around the globe quickly, and this would result in high morbidity and mortality, disruption of the economy, and, in some cases, the collapse of governments,” says Baric.
That’s why researchers want to learn as much as they can about MERS. It’s a type of virus called a coronavirus, which is the special focus of Baric’s lab.
However, a recent decision from the Obama administration has decided to stop govt-funded research on this virus, and also on influenza and SARS.
The Obama administration was concerned about any research that could make the viruses more dangerous, so they wanted to stop and review studies to see if they could make these germs capable of causing more disease or spreading easily through the air.
“I don’t think it’s wise or appropriate for us to create large risks that don’t already exist,” saysDavid Relman, a microbiologist at Stanford University.
Ad for for Baric,
Asked if his lab is creating any new forms of these viruses that would be more dangerous for people, Baric replied: “Absolutely not. And we do more genetics in than probably anyone else in the world.”
He says he may not ultimately agree with whatever guidelines are put in place, but “if that’s what it takes to continue the research, then that’s what we’ll do. Ultimately we are responsive to the public.”
What do YOU think? Is this type of research too dangerous? Is the moratorium a good idea? Or is the government overstepping its bounds? Participate in the poll, and let us know!
The latest It’s Okay To Be Smart video from Joe Hanson gives the full story on EBOLA. This includes the history, the biology, the origins of Ebola and much much more! All of this knowledge is sure to fight FEAR-BOLA!
Don’t panic. If we arm ourselves with good science, there’s nothing we can’t handle.
This is a terrific scientific summary about ebola, viral levels, and infectivity! I have been waiting for this! Super psyched its from a student at PENN!!! Someone please send this to politicians, fear-mongerers, and anyone else suffering from FEAR-BOLA!
Why people without symptoms aren’t going to give you Ebola
Fear of Ebola has put many on high alert and there is increasing anxiety about the possibility of individuals with minimal exposure and no symptoms introducing the virus into communities – people such as Craig Spencer, the doctor who contracted Ebola while working in Guinea who then went bowling and rode the subway in New York before exhibiting symptoms.
Fear has kept people away from school and work, despite reassurances from the World Health Organisation (WHO) and the American Centers for Disease Control and Prevention (CDC) that someone with Ebola becomes contagious only once they develop symptoms.
In light of this, it is worthwhile explaining the data behind these assurances, which the WHO and CDC haven’t done, to make clear why we are so confident that people without symptoms can’t give you Ebola.
The Kikwit outbreak
There are five different known types of ebolavirus (the genus), including Zaire ebolavirus, which is behind the 2014 outbreak in West Africa. The best epidemiological data on Ebola virus (the disease) transmission comes from the 1995 outbreak in Kikwit, in the Democratic Republic of the Congo, which was caused by the same species as the current epidemic.
The Kikwit outbreak marked the first appearance of EBOV since its initial discovery in 1976, and a team from the CDC and WHO extensively studied what interactions, and when, led to EBOV transmission. The team followed 173 household members of 27 active cases until the end of the outbreak. They were able to identify who became sick and which interactions between sick people and their family members during the incubation period, early illness, and late illness were associated with transmission.
The biggest risk factors for becoming infected with Ebola virus, identified in the 1995 outbreak, and outbreaks in 1979 and a different species in 2000-2001, are direct physical contact with a sick person, primarily with bodily fluids such as blood, vomit, diarrhoea, and later in the disease, sweat and saliva. Ebola virus can survive outside the body for anywhere from hours to days, depending on the environmental conditions such as dampness and exposure to sunlight. Therefore, infection by contact with objects contaminated with bodily fluids is also theoretically possible, but is likely to be rare in practice.
During the Kikwit outbreak, 95 family members of the 27 cases had direct physical contact with someone who was actually sick, and 28 of these individuals became sick with Ebola themselves. Of the 78 family members who did not have direct physical contact with a sick person, none got Ebola. Among these 78 were family members who had extensive contact with infected individuals during the incubation period, including such close interactions such as touching and sharing a bed.
Virus levels in the blood
We also have data on virus levels in the blood that suggests people aren’t contagious before they are symptomatic. As the most infectious fluids are blood and vomit, the amount of virus in these fluids is a critical factor in whether an infected person can transmit the virus.
We understand this to be true in West Africa today as well. Our tests are extremely sensitive, and it’s clear that little virus is present in the blood when symptoms appear and even less during the incubation period, explaining why we aren’t able to diagnose people during this time.
Without these high levels of virus in the blood and other fluids, it is exceedingly unlikely that someone would be contagious.
To be fair, however, we never say never in biology and we can’t prove a negative, so no experiment could tell us that transmission during the incubation period is truly impossible. But what we do know is that it doesn’t seem to happen in past or current outbreaks and is biologically implausible. Rather than panic about getting Ebola from a seemingly uninfected neighbour, we should focus on isolating people at the first sign of symptoms so that when they do get sicker and become highly contagious, they aren’t in a position to infect anyone else.
In light of Dallas nurse Amber Vinson’s recent travel on a commercial airline with a mild fever before she was diagnosed (now Ebola-free), many people want to know whether individuals in the early stage of the disease – say with just a fever – are contagious. School districts and employers have been treating Pham’s fellow airline passengers as being at risk of disease and as potential transmitters, but should they be?
The answer is almost certainly no. Levels of virus in the blood increase rapidly following the onset of symptoms, but at this early stage people aren’t vomiting or bleeding, which would expose those around them to potentially infectious fluids, and onward transmission.
While it’s true that virus can be found in fluids such as saliva and sweat, this mostly occurs later in disease, when the individual would be hospitalised. During the 1995 outbreak having a conversation, sharing a meal and sharing a bed with people in the early stage of disease were not associated with becoming infected oneself.
Later in the disease this changes, but it seems clear that slightly sick people aren’t much of a risk to those around them. Anecdotally, we also now know that the family of Thomas Eric Duncan, the man who contracted Ebola in Liberia and was later cared for by Vinson and Nina Pham, remained healthy despite being in an apartment with him for the first several days of his illness.
Knowing this, we shouldn’t be barring people with no direct exposure from school, or work. It’s not “an abundance of caution” to do this, it’s harmful. Unless you sat next to the sick nurse on that plane, your exposure was almost zero. If you did, you’re still almost certainly fine. If you had contact with her before she was sick, you definitely are. Still, it’s natural to worry, which is why we need to stop the epidemic in West Africa, mostly for them, but also so we can stop worrying about Ebola virus here at home.
Stephen Goldstein does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.
A study published in mBio (shout out for OpenAccess!) found that rats in New York City are very, very, very ‘dirty.’ The authors (Shout out to Columbia!) analyzed the pathogens carried by 133 rats using high-throughput genetic sequencing, and discovered that NYC rats carry many bacteria and viruses that can cause human disease! Press release here.
We found that these rats are infected with bacterial pathogens known to cause acute or mild gastroenteritis in people, including atypical enteropathogenic Escherichia coli, Clostridium difficile, and Salmonella enterica, as well as infectious agents that have been associated with undifferentiated febrile illnesses, including Bartonella spp., Streptobacillus moniliformis, Leptospira interrogans, and Seoul hantavirus. We also identified a wide range of known and novel viruses from groups that contain important human pathogens, including sapoviruses, cardioviruses, kobuviruses, parechoviruses, rotaviruses, and hepaciviruses.
That’s not good. Now, I’ll only be thinking about all of these pathogens when I’m waiting on the subway platform and look down to see the most common NYC wildlife under the tracks. Guess we should all be paying a little more attention to the diseases that these rats are carrying around all over our city.
Our findings indicate that urban rats are reservoirs for a vast diversity of microbes that may affect human health and indicate a need for increased surveillance and awareness of the disease risks associated with urban rodent infestation.
For all of the curious minds like me, you have to ask yourself… where did they get these rats? and how did they catch them? First off, the rats were humanely euthanized after being trapped. Below are the methods from the paper describing the rat collection.
The preliminary nature of this study and the significant complexities involved in trapping rats indoors in NYC necessitated an approach of convenience sampling. An effort was made to target neighborhoods likely to be impacted by the presence of rats, specifically those with high rodent and human density or a high probability of rodent-human interaction. Five sites were selected in midtown and lower Manhattan, comprised of three high-density housing complexes, one very large indoor mixed-use public space (transportation, food service, retail, and commercial), and one small urban park in a densely populated area. The residential sites are on blocks of average density for Manhattan and below-average median income (64). The mixed-use public space is in a neighborhood notable for an exceptionally high daytime population size and density, and the park was chosen based both on its location (adjacent to the residential sites) and high block density.