Ebola Transmissibility

[JimO]

I thought it would be useful to post reports of transmission that might not conform to the current WHO definition. To start it off, here is the current information on ebola transmission from the WHO website.

Transmission

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.

Health-care workers have frequently been infected while treating patients with suspected or confirmed EVD. This has occurred through close contact with patients when infection control precautions are not strictly practiced.

http://www.who.int/mediacentre/factsheets/fs103/en/

 

[JimO]

Re: Ebola Transmissibility

:tiphat: alert

Ebola: Doctor's Death Sparks Fear, 70 Persons Quarantined in Port Harcourt

Onyebuchi Chukwu

Paul Obi
The death of a doctor in Port Harcourt over Ebola Virus Disease (EVD) which was unknown to many has sparked fears across the country.

This came as 70 persons have already been quarantined in Port Harcourt, Rivers State. Minister of Health, Prof. Onyebuchi Chukwu at a briefing in Abuja told journalists that the doctor who died in Port Harcourt had his blood sample tested positive after death. He also said that 70 persons have been placed under surveillance in Port Harcourt.

The minister explained that the wife of the doctor has also been quarantined alongside others believed to have had contact with the doctor and patient who he attended to.

Speaking of the patient, Chukwu said, "One of them is a primary contact of the index case (Mr. Patrick Sawyer). Even though presently he does not have EVD but further laboratory tests indicate that he had suffered EVD."

"This primary contact of Mr. Sawyer’s evaded our surveillance team in the last week of July 2014 and travelled out of Lagos to Port Harcourt where, as we now understand, he consulted with a doctor and was apparently treated for some symptoms. After four days, following a manhunt for him, he returned to Lagos by which time he was found to be without symptoms."

"This case would have been of no further interest since he had completed the 21 days of surveillance without any other issue, but for the fact that the doctor who treated him died last Friday, 22nd August, 2014."

http://www.flutrackers.com/forum/showthread.php?t=227005

 

[JimO]

Re: Ebola Transmissibility

:tiphat: Emily

http://www.telegraph.co.uk/health/11...ola-virus.html

Baby may have infected Briton with deadly Ebola virus

British nurse William Pooley may have contracted the deadly Ebola virus while playing with a baby whose mother had died in a treatment centre
...

Like other health workers, Mr Pooley initially took precautions handling the infant since his mother was diagnosed with the virus and later died. But he played with him freely after the baby tested negative for the disease, she said.

"Mr Pooley and some other nurses fell in love with the boy and would play with him in their free time," she said.

The child was tested again after he developed a fever and tested positive for Ebola the second time around.

He died on August 24 -- the same day that Mr Pooley was diagnosed.

It is not clear why the initial test result for the child came out negative, although experts say the virus can sometimes go undetected and recommend several tests.

Another nurse known to have played with him has also tested positive for the disease, the nurse supervisor added. ...

http://www.flutrackers.com/forum/showthread.php?p=544181#post544181

 

[sharon sanders]

Re: Ebola Transmissibility

Also please see:

Ebola - Possibly transmitted through droplets but not exactly airborne

http://www.flutrackers.com/forum/showthread.php?t=226958

 

[Shiloh]

Re: Ebola Transmissibility

Source: http://thenewsnigeria.com.ng/2014/08/28/how-ebola-virus-reached-east-of-nigeria/

How Ebola virus reached east of Nigeria
Aug 28 2014 - 4:43pm

...?This case would have been of no further interest since he had completed the 21 days of surveillance without any other issue, but for the fact that the doctor who treated him died last Friday, 22nd August, 2014.

?Following the report of this death by the doctor?s widow the next day, the case had been thoroughly investigated and laboratory analysis showed that this doctor died from EVD....

Does this mean that the 21 days quarantine is insufficient?

 

[Rocah]

Re: Ebola Transmissibility

Has there been any previous studies of Ebola outbreaks indicating asymptomatic carriers?

There is mounting anecdotal evidence that for some people at least the symptoms are significantly milder (diplomat in Nigeria) yet they are able to infect, and some maybe infectious before symptoms materialize (baby that maybe infected William Pooley - I very much doubt they would have played with the child if it had exhibited fever).

 

[JimO]

Re: Ebola Transmissibility

Koindu Town Chief Dies as Ebola Makes a U-turn in Kissi Teng

The Town of Koindu in the Kissi Teng Chiefdom Kailahun District, Chief Moses Foryoh who doubles as Bursar of the Kissi Bendu Secondary School, on Thursday 28th August 2014 died at the Kaiya Ebola Isolation Center in Koindu. The death of the chief has created panic and standstill in the Koindu Township and its environs according to sources. Relatives of the deceased told our reporters that he just collapsed last Wednesday and was taken to the isolation center for medical examinations.

?He did not complain of any sickness, he fell down just after bath and as we rushed to help him the medical personnel advised us not to touch him and was taken to the isolation center? our source revealed.

more...

http://news.sl/drwebsite/publish/article_200526098.shtml

 

[Gemineye]

Re: Ebola Transmissibility

While the cause of death could very well be Ebola, it has not been confirmed. It could also be just about anything else, including a heart attack. We'll have to wait and see.

 

[Emily]

Re: Ebola Transmissibility

Has there been any previous studies of Ebola outbreaks indicating asymptomatic carriers?

There is mounting anecdotal evidence that for some people at least the symptoms are significantly milder (diplomat in Nigeria) yet they are able to infect, and some maybe infectious before symptoms materialize (baby that maybe infected William Pooley - I very much doubt they would have played with the child if it had exhibited fever).

Welcome, Rocah! I think there was a study done that indicated that there are asymptomatic infections, but these people who never show symptoms were believed to not shed virus.

I haven't seen an infectious pre-symptomatic window discussed in a study yet, but maybe someone else did. I wondered about that, too, regarding the suspected baby to nurses chain of transmission.

 

[Graupel]

Re: Ebola Transmissibility

The ECDC also says the probability of an infected person getting on a flight in the first place is low, given the small overall number of Ebola cases. Moreover, functional health systems should be able to prevent onward spread from any exported cases.

http://www.nature.com/news/largest-ever-ebola-outbreak-is-not-a-global-threat-1.15640

Staggering that a piece from 1 month ago is so out-of-date!

 

[mac68DC]

Re: Ebola Transmissibility

The ECDC also says the probability of an infected person getting on a flight in the first place is low, given the small overall number of Ebola cases. Moreover, functional health systems should be able to prevent onward spread from any exported cases.

http://www.nature.com/news/largest-ever-ebola-outbreak-is-not-a-global-threat-1.15640

Staggering that a piece from 1 month ago is so out-of-date!

I am going to quote a section here in case the article ever disappears.

" ...but that there is little chance of spread overseas. There is no reason to assume that an exported case ? be it to Lagos, a city of 17 million people, or any other place ? will spark new outbreaks, because Ebola is not highly contagious"... Declan Butler, 30 July 2014

 

[JimO]

Re: Ebola Transmissibility

Welcome Graupel!

It is amazing what has happened in a month. All the experts were saying this until the Sawyer case appeared. I wonder how long before they are forced to admit that people can be contagious while showing no obvious symptoms?

The ECDC also says the probability of an infected person getting on a flight in the first place is low, given the small overall number of Ebola cases. Moreover, functional health systems should be able to prevent onward spread from any exported cases.

http://www.nature.com/news/largest-ever-ebola-outbreak-is-not-a-global-threat-1.15640

Staggering that a piece from 1 month ago is so out-of-date!

 

[AnnaLisa]

Re: Ebola Transmissibility

I'm glad to hear some one else was thinking that too. I was getting concerned that perhaps I had some psychopathology.

 

[foxp3]

Re: Ebola Transmissibility

I asked about this last week and was really pleased to have got quite a few good replies from other members about asymptotic carriers, and the percentage of people whose incubation is longer than 21 days. etc. Link to that thread is below.

http://www.flutrackers.com/forum/showthread.php?p=543540

 

[Emily]

Re: Ebola Transmissibility

Interview with Nurse Monia Sayah of Doctors Without Borders:

<iframe src="http://www.pri.org/node/68061/embedded" height="76" width="320" ></iframe>

"You never know who's sick and who's not. People can hide their symptoms very well when they want to - especially when fear takes over. But as long as you take a 2 meter distance you're fine..." (They stay behind patients when they have to get closer, so if they cough the droplets are headed away from both the provider and the patient.)

http://www.pri.org/stories/2014-08-05/story-one-guinean-man-who-survived-ebola

Further along in the interview she says she has encountered "lots of survivors" and emphasizes that early treatment is helpful. Children and pregnant women are most at risk.

 

[foxp3]

Re: Ebola Transmissibility

Yet others claim the opposite......that few survive. Quote from Dr Dermott a UK doctor who just returned . She worked with Dr Kent Brantly and Nancy Writebol and took over the running of the unit after they were evacuated.

Of the 60-100 patients she treated during her time there, just three survived.
"It felt like we were sitting on a time bomb which was slowly exploding under us and there was nothing we could do," said Dr MacDermott

http://www.independent.co.uk/news/u...-for-three-weeks-returns-to-work-9694867.html

 

[Emily]

Re: Ebola Transmissibility

I suppose there could be many reasons one facility would have more apparent success than another. These two facilities were in different countries managed by different NGO's. The patients may have been coming in sicker to the SIM facility to begin with and the facility may have been stressed by the loss of providers by the time Dr. Dermott got there.

One thing a couple of patients credit as having helped them is simply being strongly encouraged to eat during a period of no appetite and stomach pain.

 

[foxp3]

Re: Ebola Transmissibility

That makes sense as being able to absorb any nutrients from the food would help restore the electrolyte balance, where as water alone won't address this. As long as the patients intestines can still work enough for transfer to occur. R ead somewhere on this forum that they are seeing a lot of cardiac problems in patients, which is probably caused by electrolytes not being in the right concentration. The poor patients can't even get routine bloods done in most of the clinics, so the doctors are having to treat by guess. Not seen any IVs on the patients either, and not even iisotonic, hypotonic available according to front line workers. Basic care.

You raise an excellent point about variability in mortality rates between countries. Wonder if they have produced any statistics on this, or perhaps such statistics would be unreliable at this point due to ongoing case numbers, and poor records. If they could target the poor performing ones, then they could turn the public image of death houses into healing hospitals, encouraging more people to seek help earlier on.

Proper analysis and epidemiology studies may come after.....if there is an after.

 

[mac68DC]

Re: Ebola Transmissibility

Early immune responses accompanying human asymptomatic Ebola infections

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1906073/

"ABSTRACT
In a recent study we identified certain asymptomatic individuals infected by Ebola virus (EBOV) who mounted specific IgG and early and strong inflammatory responses. Here, we further characterized the primary immune response to EBOV during the course of asymptomatic infection in humans....Recently, we identified several individuals with documented close contact with symptomatic EHF patients who nonetheless remained asymptomatic and mounted IgM and IgG responses to the NP and VP40 EBOV proteins [14]. These asymptomatic individuals were infected by EBOV at a low level over several days. This first description of asymptomatic replicative Ebola infection raised questions about the mechanism of protection. As symptomatic and asymptomatic subjects were infected by the same viral strain (as suggested by partial genotyping), the protective mechanism may have involved the transient and high circulating levels of proinflammatory cytokines (IL-1β, TNFα, IL-6, MCP and, MIP-1α/β) observed in asymptomatics early during the infection (5–7 days after the first putative infectious contact)....In a previous study we demonstrated that humans could be infected with Ebola virus without developing symptoms. These asymptomatic individuals produced specific IgM and IgG, starting between 2 and 3 weeks after initial exposure to infected body materials and reaching only moderate levels one month later. We also showed that they mounted a strong inflammatory response early in the infectious process characterized by high levels of IL-1β, TNFα, IL-6, MCP, MIP-1α and MIP-1β...."

 

[foxp3]

Re: Ebola Transmissibility

Bam Bam posted this article in the thread I linked to, it was very interesting . So basically I summerised the paper at the time ( correct me if wrong) to mean that a combination of 2 outbreaks in Gabon in 1996. 119 patients with clinical symptoms, and 24 cases of proven seroconversion but asymptomatic infection. (These individuals did not have prior immunity to Ebola as they initially produced IgM then few weeks later IgG). So infection in non immune induviduals need not produce disease. Paper concluded early immunological events determine outcome, i.e. fatal vs recovery vs asymptomatic. Better outcomes were linked to early strong inflammatory responses including cytokines IL-1, IL-6 and TNFalpha. ( high IL-6 must have produced some raises in temperature abet yransient), Also monocytes and macrophage attracting chemokines. They kept viral load low in initial stages.

I guess genotype and co existing conditions, and parasite load ( which will mop up chemokines via their decoy receptors so not allowing initial strong response), will all polarise the initial immune response. Route of antigen exposure may also play a role.
Quote from paper: These asymptomatic individuals were infected by EBOV at a low level over several days. Wonder how they quantified their daily exposure, that bit of article seems a bit strange.

As I previously said the article does not really address if asymptomatic patients can pass the virus on, however the fact they could not detect virus in their serum, and only in WBC after 2 round of PCR gives the impression they must have had very low viral levels.

Mac68dc do you think asymptomatic patients can be carriers because I don't have a clue.

Fp