Ebola as an STD in Urban Environments.

[mac68DC]

I was brainstorming about the implications of Ebola now spreading in more urban environments. (other than sheer population density). One thing I am curious about is the increased possibility that the reproductive ratio of the virus could be influenced by men who have survived Ebola. There is the possibility that they can pass it to their partners as an STD. It has been shown that the virus has the potential to be passed on sexually after a man has survived a case of Ebola.

Given that the death rate of this strain is significantly lower than other occurrences, and given that young adults in an urban environments tend to have a more robust night life than rural ones - I am wondering if this could now be a serious issue whereas in the past, it probably wasn't.

One of the problems I see is that this circumvents the tendency of the virus to "burn out" due to the higher survival rate (relatively) and the ability to pass on the virus for a much longer period of time (3+ months) than a symptomatic person (about 10 days max). Not to mention that a person who has survived Ebola has no visual indicators.

While you would think that someone who survived Ebola would not knowingly pass it on, I am betting there are many who just don't know they can pass it on. Some who survive Ebola might not even know they had Ebola. There are strong indications that there are many people surviving Ebola outside of the supervision of medical institutions.

This might hurt contact tracing and containment as well. It will be a pain if an area is cleared only to have a transmission occur months later.

I wonder if there are metrics that could be warning signs that this is happening - perhaps in the gender ratios of those getting Ebola.

I had a hard time finding studies on this. Would really appreciate it if anyone has some links to some.

 

[mac68DC]

Re: Ebola as an STD in Urban Environments.

A good study from the Journal Of Infections Diseases.

http://jid.oxfordjournals.org/content/196/Supplement_2/S142.full

..."The isolation of EBOV from semen 40 days after the onset of illness underscores the risk of sexual transmission of the filoviruses during convalescence. Zaire EBOV has been detected in the semen of convalescent patients by virus isolation (82 days) and RT-PCR (91 days) after disease onset [5, 14]. Marburg virus has also been isolated from the semen and linked conclusively to sexual transmission 13 weeks into convalescence"...

 

[JJackson]

Re: Ebola as an STD in Urban Environments.

I trust that someone will also look at sex industry workers.

In the effected areas it is common for lorry drivers to travel away from home for long periods and, where in the West may may have motorway services, they either sleep in the cab or at a 'comfort station' which provide cheap food/drink, a basic bed and a local 'hostess' - if desired.

I have been watching the footage of trucks queuing up at closed boarders and wonder what else may be accumulating there.

 

[sharon sanders]

Re: Ebola as an STD in Urban Environments.

I am not aware of any studies that have established a direct link between ebola positive semen and actual transmission resulting in a test positive infection. I think it is too early in this outbreak to establish this connection because many other routes for infection are available. It is impossible at this point to rule those other routes out.

However, it is entirely possible ebola infection via semen is occurring.

At this point male to female cases are roughly 25% to 75%, respectively. This ratio may be explained by the fact that more women cook bush meat than men, women are poorer and less likely to seek early treatment, women have increased exposure to ebola contacts because they are more likely to be caregivers, and/or sexual transmission.

I think we simply do not know how many of the current cases are due to sexual transmission. I think a very conservative approach must be taken. I think all people in the affected countries should assume anyone may be a carrier of the ebola virus and all people should employ the most disease prevention techniques available to them.

Sadly - for the poorest of the poor, the lack of running water and sanitation makes even routine washing of hands a luxury.

Ideally, all people would have access to clean water, sanitation, hand gel stations, condoms, disposable gloves and masks, among other things.

 

[mac68DC]

Re: Ebola as an STD in Urban Environments.

...At this point male to female cases are roughly 25% to 75%, respectively. ...

I went looking for some sort of baseline for prior rural outbreaks and found this link (THE EPIDEMIOLOGY OF EBOLA HAEMORRHAGIC FEVER IN ZAIRE, 1976) with great breakouts (AGE AND SEX DISTRIBUTION OF CASES, ZAIRE, 1976):

http://www.itg.be/internet/ebola/ebola-24.htm

"...All ages and both sexes were affected. Females predominated, mainly in the age groups 5-14 and 15-29 (Table 1)..."

So it seems the ratio discrepancy was occurring even in rural areas, which would reinforce what you posted.

 

[mac68DC]

Re: Ebola as an STD in Urban Environments.

...While you would think that someone who survived Ebola would not knowingly pass it on....

Well, actually, I should qualify my statement that I made in the OP. I suppose someone would knowingly pass it on if they were some sort of fanatic/terrorist or mentally ill person. (well I guess those categories are not mutually exclusive).

For the first few days, it would be very hard to catch a person using this as a delivery system. They would probably target some small local segment of a country's sex worker industry . No idea how effective it would actually be though. My guess is probably not very.

 

[Donners]

Re: Ebola as an STD in Urban Environments.

I am not aware of any studies that have established a direct link between ebola positive semen and actual transmission resulting in a test positive infection.

The closest I'm aware of is with Marburg, where the wife of a man who recovered from Marburg in 1967 was infected over twelve weeks after his recovery.

It's referred to in Jens Kuhn's epic tome Filoviruses at page 66; unfortunately I can't find an online link for it.

 

[mac68DC]

Re: Ebola as an STD in Urban Environments.

Why I think this was not a big problem in the past:

• Most infected were women.
• If the woman was infected, most likely those close to her were infected through traditional ways and these people became immune if they survived.
• If the man was infected, most likely those close to him were infected through traditional ways and these people became immune if they survived.
• There were much fewer male survivors due to quantity infected and mortality rate of past outbreaks.

Why I think this will become a huge problem in this outbreak:

• People are less cooperative and forthcoming as it is - let alone an STD angle.
• Higher rate of survival.
• Critical mass of males who have survived Ebola and are not tracked.
• The potential to engage with new partners that have not had Ebola yet.
• Once traditional containment has run its course, STD version will constantly undo all of it - over and over.

Because of the numbers and population densities involved, I really feel like Ebola can survive as an STD once its non-STD transmission has been minimized. (but of course it restarts the traditional transmission).

This will also have a propensity to create relatively weaker forms (but still deadly) mutations of the virus, which perversely is even worse than a stronger one, as it can go underground much easier.

 

[mac68DC]

Re: Ebola as an STD in Urban Environments.

Another important epidemiologic feature of Ebola virus VHF is that the testis is often involved in the infection... and that viral shedding in semen may continue for weeks. Prevention of sexual transmission...is, therefore important.

Arboviruses and Viral
Hemorrhagic Fevers (VHF)
file:///C:/TextFiles/arbovirus_y_fiebres_hemorragicas.pdf

 

[mac68DC]

Re: Ebola as an STD in Urban Environments.

Perhaps there is even a chance of sexually passing on Ebola without ever showing symptoms of Ebola.


Human asymptomatic Ebola infection and strong inflammatory response
http://www.thelancet.com/journals/la...405-3/fulltext

"Ebola virus is one of the most virulent pathogens, killing a very high proportion of patients within 5—7 days. Two outbreaks of fulminating haemorrhagic fever occurred in northern Gabon in 1996, with a 70% case-fatality rate. During both outbreaks we identified some individuals in direct contact with sick patients who never developed symptoms. We aimed to determine whether these individuals were indeed infected with Ebola virus, and how they maintained asymptomatic status.
...
These findings show that some individuals were infected with the virus without developing symptoms. Results from previous outbreaks had only indicated that such an asymptomatic infection was possible.
...
Although it is possible that some individuals mount a local cellular mechanism that inhibits replication, or that the infectious dose in these individuals was so small that even a modest inflammatory response could clear virus, this response may be involved in some way in the rapid control of virus and absence of symptoms. The public-health impact of Ebola infection needs also to be reassessed in light of these new findings. The risk of transmission via blood products donated by such individuals or via semen should be taken into consideration in public-health policy since infectious filovirus have already been found in semen from symptomatic patients 2—3 months after symptoms"

 

[kondor]

Re: Ebola as an STD in Urban Environments.

mac68DC, I believe you are correct to highlight the problem with transmission as an STD.

edit

There is, in my mind at least, a real worry that a sex worker who has not yet started showing signs of infection might be able to pass on the virus. And even if there is only a small window of time for this to happen I believe the amount of people they sleep with allow the virus to leap into strangers.

It is all too easy for those of us outside of these circles to be ignorant of them, and hope that people signing up to the "do not eat bush meat" and "do not touch sick people" will be enough to stop the spread. But I wonder if some messages will need to be added to those in order to reduce the chances of STD spreading of this virus.

 

[Gert van der Hoek]

Re: Ebola as an STD in Urban Environments.

Ian Mackay wrote a blog on this subject:

Ebola virus in semen is the real deal....

The World Health Organization (WHO) Ebola virus disease factsheet notes that ebolaviruses may be transmitted via the semen of a male who is getting over an ebolavirus infection, for a period of 7-weeks (~49-days).[1]

The European fact sheet for health professionals and a Public Health Agency of Canada Pathogen Safety Data Sheet both note the 7-week figure, the latter also adds a 61-day figure.[2,3]

The United States Army Medical Research Institute of Infectious Diseases (USAMRIID) Medical Managements of Biological Casualties Handbook (7th edition) notes a 3-month (~80-days) period, during which one should probably avoid sexual relations so as not to deliver virus directly to a mucosal surface.[4]

Semen is therefore listed as one of the body fluids from which Ebola virus disease may be contracted.

Read more, including a list of relevant researchpapers.

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