Posts Tagged ‘Congo fever’

CCHFV in South Africa

1 February, 2013

I am indebted to the National Institute for Communicable Diseases (NICD) in Johannesburg for their very informative newsletter, from which I culled this.

I would also like to very sincerely congratulate Professor Barry Schoub, a long-time former Director of the NICD, on his  African Society for Laboratory Medicine (ASLM) Lifetime Achievement Award!  Very well deserved.

Crimean-Congo haemorrhagic fever

Two cases of Crimean-Congo haemorrhagic fever (CCHF)  acquired in South Africa have been laboratory confirmed  in January 2013.

On 1 January 2013, a 31-year-old male working as a  game warden on private game ranch near Jagersfontein  (Free State Province) presented with clinical features  suggestive of CCHF. The patient did not report any tick  bites or direct exposure to unprocessed meat or  slaughtering of animals. The Centre for Emerging and  Zoonotic Diseases of the NICD/NHLS confirmed infection  with CCHF virus by PCR and serology testing.

A second case of CCHF was laboratory confirmed on 12  January 2013 in a 44-year-old male hospitalised in  Bloemfontein, Free State Province. He had been on a  farm in Pomfret, North West Province (situated ±5 km  from the border with Botswana), where he was bitten by  a tick. Three days later he developed symptoms, and  presented with fever, rash, conjunctivitis and pharyngitis.  No laboratory-confirmed cases were identified in 2011- 2012.

Human CCHF cases have been reported annually  from South Africa since 1981, when it was first  recognised in the country; between 0 and 20 cases of  CCHF are diagnosed each year. Through nearly thirty  years of passive surveillance, a total of 187 cases has  been laboratory confirmed. Although cases have been  reported from all of the nine provinces, more than half of  the cases originate from the semi-arid areas of Northern  Cape Province (31.5% of cases) and Free State Province  (23% of cases).

CCHF infection is generally asymptomatic in many species  of wildlife (including antelope) and livestock animals  (including cattle, sheep, goats, hares and ostriches).  Humans  become  infected  sporadically  by  ticks,  particularly  Hyalomma ticks, which are both reservoirs  and vectors for CCHF virus. Other modes of transmission  include direct contact with blood/tissues of infected  animals, and in the case of healthcare workers, through  direct contact with the blood/tissue of infected patients;  nosocomial outbreaks are well described and have been  associated with high mortality rates. Disease may be  severe in people, with case-fatality rates reported as 3 –  30% across various studies.

Detailed information for healthcare workers regarding  CCHF can be found on the NICD website  http:// http://www.nicd.ac.za/ (see General Public FAQ, or Health Workers FAQs here).

Monkeypox vaccine?? We don’t need no monkeypox vaccine….

22 December, 2011

An in-press article in Vaccine that was tweeted by MicrobeTweets (well worth signing up to, BTW) has the intriguing title “Whither monkeypox vaccination?”

Now, some background to this: monkeypox virus is a rather nasty relative of smallpox (family Poxviridae; subfamily Chordopoxvirinae, genus Orthopoxvirus), meaning it is a large dsDNA virus (170-250 kb) with a complex structure.  The virus is endemic in remote forest areas in central Africa – principally in the Democratic Republic of the Congo – and naturally infects a number of animal species, including giant pouched rats (Cricetomys sp.), dormice (Graphiurus sp.) and African squirrels (Heliosciurus, Funisciurus), as well as laboratory monkeys, which is how it was isolated and got its name.

Monkeypox gets transmitted to humans by contact with infected animals: this includes by simple handling, as well as by exposure to meat and blood of butchered animals.  It causes a disease in humans that is very similar in appearance to smallpox, with a case fatality rate of 1-10%, but is apparently far less easily transmitted person-to-person.  It caused only sporadic and limited outbreaks in Africa and was of limited interest until an outbreak in the USA in 2003, which was linked to young prairie dogs kept in a pet store in close proximity to an infected Gambian pouched rat (Cricetomys gambianus) recently imported from West Africa. Seventy-three people were reportedly infected, among whom there were no fatalities.  The CDC recommends vaccination of people exposed to human or suspected animal cases with smallpox vaccine, as this protects animals from experimental lethal monkeypox challenge.

The Vaccine paper makes the point that the potential for monkeypox virus (MPX) to fill the disease niche recently vacated by smallpox was evaluated in the 1970s – and discounted, largely because human-to-human spread was inefficient enough for outbreaks not be self-sustaining – thus, although smallpox vaccine protected against MPX, the WHO thought there was insufficient justification to continue vaccination.

Now, however, the incidence of the virus in humans

“…appears to have markedly increased. In addition to diminished vaccine-induced orthopoxvirus immunity, there have been profound social and demographic changes that have increased human MPX exposures and the likelihood of severe disease. Recurrent civil war and subsequent economic decline have forced rural residents to flee deep into the rain forests for extended periods of time, disrupted traditional village life and increased dependence on hunting for sustenance, thus increasing exposure to animal reservoirs of MPX.”

So, in other words, people are getting a whole lot more exposure to sick animals.  Increasingly, by eating them.  The paper goes on to say:

“Although orthopoxviruses are relatively genetically stable MPX has diverged into two clades with different levels of virulence. As incidence rises, each new MPX infection provides an opportunity for viral evolution or adaptation that may result in a more virulent or contagious variant capable of sustained person-to-person transmission. These new circumstances merit a re-evaluation of the need for immunizing against MPX”.

So – that should be relatively simple, surely?  I mean, South Africa alone has millions of doses of smallpox vaccine safely frozen away from the 1970s?  Not so fast….

“However, in an era where the threat of smallpox is not imminent and there are conditions such as AIDS, tissue transplantation, and therapies for cancer and autoimmunity that cause immunodeficiency, the adverse events associated with live vaccinia are no longer considered acceptable for the general population.”

The paper goes on to mention how all sorts of supposedly safe new smallpox vaccines have been deposited into biodefence stockpiles, based on animal testing.

And there it is again – that word “biodefence”, in the context of human vaccines – implying that there is a “biothreat” to counter.  Specifically, in this case, the spectre of weaponised smallpox.

The authors go on to make reasonable statements about surveilling for monkeypox in central Africa, and vaccinating people at risk, and say that treatment options should also be investigated given that clinical diagnosis is relatively easy.

They also close with this:

“If immunization studies in developing countries are contemplated to support the licensure of orthopoxvirus vaccines for industrialized countries or for military purposes, then provisions from those countries or organizations should be secured to distribute successful products in endemic regions where the products were tested.” [my emphases]

I should hope so.  I should really, really hope so – because then one country’s biodefence interests could end up benefitting quite a few others, who are the ones who really need the product.  Now, while you’re busy with that, what about vaccines for Rift Valley fever, Crimean-Congo haemorrhagic fever and Chikungunya – which are actually far more serious a problem, in a much bigger geographical area?

 

Deadly Zambian fever: deja vu all over again

7 October, 2008

The news media are presently fascinated by the appearance of what looks like a new and nasty virus from my old home country, Zambia: see a link to The Times article of 7th October for the official word.

Which is “Don’t Panic”, written in large, friendly letters across the face of the newspaper….

From The Times article by Sashni Pather:

Disease transmitted via bodily fluids

THE deputy director of the National Institute for Communicable Diseases has assured the public that there is no need to panic, despite the fact that four people have been killed by an unknown, highly contagious virus.

Doctor Lucille Blumberg, who also heads up the NICD’s epidemiology unit and consults to its special pathogens unit, referred to the death of Cecilia van Deventer, 36, as an “isolated case” and said test results were not yet available.

…A paramedic, Hannes Els, 33, who treated the critically ill Van Deventer in Zambia, and brought her to the Morningside Medi-Clinic in Sandton on September 12, died last Thursday after being infected with the highly contagious disease.

On Sunday a nurse and a cleaner, who had possibly been exposed to the disease, died.

Blumberg said: “The cause of death of the cleaner is still being investigated. We are busy conducting tests on all four deceased. The cleaner might not have been killed as a result of the virus.

“This is an isolated case. There have been no other reported cases in Lusaka, Zambia. “”

OK, so no obvious panic there, then – but disturbing echoes of another incident from 1996, when a Gabonese doctor was medevacced in to South Africa, and passed on an Ebola virus infection to a theatre nurse, Marilyn Lahana.  He recovered, and she died – and there was close to panic in the land, as chronicled here.  And here we are again….  Incidentally, anyone who wants to see how the first Ebola outbreaks of the electronic age unfolded can see a day-by-day history here, on my original Ebola pages.  Still accessible, to my surprise!

That wonderful institution that is ProMED - who were the first people to break hard news of the Kikwit Ebola outbreak back in 1995, came to the attention of the serious medical reporting world as a result – has a slightly different view of the whole thing – and some interesting details not in the general news story.  In this morning’s digest:

UNDIAGNOSED FATALITIES – SOUTH AFRICA ex ZAMBIA (02)
***********************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the International Society for Infectious Diseases
<http://www.isid.org>

[1]
Date: Mon 6 Oct 2008
Source: South African Broadcasting Corporation News online [edited]
<http://www.sabcnews.com/south_africa/health/0,2172,177844,00.htm>

A 4th person with viral haemorragic fever (VHF) symptoms has died. The virus has already claimed the lives of a Zambian national and 2 other people at the Morningside Clinic in Johannesburg. The woman was a cleaner at the clinic.

The National Health Department has issued an alert in Gauteng following these deaths. Unconfirmed tests indicate they may have died of [a] fatal viral haemorragic fever. An Outbreak Response and Tracking Team has been set up to contain any further spread. The department’s Zanele Mngadi says investigations are still underway into the cause of the deaths.

Mngadi confirmed the death of the 4th person, who was admitted at the Leratong hospital last night [5 Oct 2008]. The patient, who showed symptoms of VHF, was transferred to the Charlotte Maxeke Johannesburg
Academic Hospital, where she died. The health department says there is no need for South Africans to panic. The department’s Frew Denson says the fever is highly contagious but is only transmitted through body fluids.

It is reported that the virus can kill a person within 72 hours. VHF is an extremely infectious and life-threatening disease caused by [several different] viruses, including Ebola virus. The death rate [in the case of Ebola virus] can be as high as 90 percent. Symptoms vary but include fever, vomiting, diarrhea and bleeding.

Communicated by:
Rabelani Daswa <rabedaswa@gmail.com>

******
[2]
Date: Mon 6 Oct 2008
From: Amy Cantlay <inka@iwayafrica.com>

I have just read the posting (Undiagnosed fatalities – South Africa ex Zambia: RFI 20081005.3139) on your site, and it appears to be rather misleading. The chronological order of events (as I can gather) is as follows (None of this information has yet been confirmed.):

4 Sep 2008 – Index Case – female South African, (living in Zambia for many years) begins to suffer from flu-like symptoms.

9 Sep 2008 – She is slowly deteriorating. She sees multiple doctors in Lusaka.

11 Sep 2008 – She is admitted to hospital and deteriorates over night.

12 Sep 2008 – Paramedic is called in to evacuate her to South Africa.  He does the transfer, along with another Dr assisting.

13 Sep 2008 – Index Case dies.

14 Sep 2008 Paramedic starts to develop flu-like symptoms.

14-27 Sep 2008 – Paramedic slowly deteriorates.

27 Sep 2008 – Paramedic is diagnosed as very sick and medivaced [sic] to South Africa. Nurse who treated Index case begins to get flu-like symptoms.

30 Sep 2008 – Paramedic dies.

1 Oct 2008 – Nurse who treated Index Case is admitted to hospital.

5 Oct 2008 – Nurse who treated Index Case dies.

The information that I can gather is the following:

1. Incubation period is as little as 2 days (paramedic), but as long as 14 days (nurse).

2. Disease course is generally 4-7 days of flu-like illness with patient only becoming critically ill in 2nd week of disease.

3. Further information is that Index Case reportedly had an eschar on one of her feet, thought to be from a tick-bite. She had also been in contact with horses from Congo in the weeks preceding her illness. Transmission is hypothesized to be by 2 means: tick-borne 1st (which may have brought the disease into the human population from the animal population) followed by direct contact with bodily fluids (resulting in human to human transmission).

4. It appears further hospital staff are now critically ill in Zambia, though this has not been confirmed.

5. If the incubation period is as long as 2 weeks, then we should still be closely watching all “contact-cases” for any signs of the disease. Those in contact with the Index case should be in the clear by now, while those in contact with the paramedic and the nurse (as well as any hospital staff who are currently sick) are still at high risk. One should probably work on a 21-day incubation period/quarantine period to be safe.

6. Chances are this is a new virus (or new subtype of virus) in the [family _Filoviridae_]. The only 2 known viruses in this group are Ebola and Marburg. It looks as though [the infection] may have entered Zambia from the Democratic Republic of the Congo (DRC) through a tick (carried on a horse), but again this cannot be confirmed.

This comment assumes that labs in South Africa have already tested all known VHFs. It is unlikely to be pneumonic plague, as this would have been discovered in South Africa; however, it is still a possibility that this [putative] viral disease has been in the Southern Province of Zambia (and that the 4 reported cases seen there were not diagnosed or wrongly called pneumonic plague).

7. The important steps in control are 1. effective quarantine of sick patients, and 2. monitoring of all “in-contact” cases, with quarantine as soon as any signs of flu or fever are noted. The government should also ideally make a statement to calm the panic and prevent people from fleeing the capital (potentially carrying the disease countrywide). This disease only spreads to people who are in very close contact with sick individuals. Those family members who are potentially incubating the disease should be encouraged to stay
around Lusaka, so that signs can be picked up quickly and treatment issued rapidly….[section on use of ribavirin - effective only against Lassa fever - edited out].

Communicated by:
Dr Amy Cantlay BVSc.MRCVS <inka@iwayafrica.com>
Veterinarian
Mkushi, Zambia

[ProMED-mail thanks Dr. Cantlay for her commentary, which contributes some interesting detail. At this point, it would not be useful to speculate further on the identity of the infectious agent responsible for the deaths of the 4 Zambian patients. No doubt a firm diagnosis will be available shortly from a South African reference laboratory. Several different viruses cause viral hemorrhagic fever. Of these, Ebola, Marburg, Lassa or Crimean-Congo hemorrhagic fever viruses have not been recorded in Zambia up to the present. A comprehensive account of these and other viruses responsible for hemorrhagic fevers can be found at the US CDC website: <http://www.cdc.gov/ncidod/diseases/virlfvr/virlfvr.htm>.

So: an unknown fever-causing agent, possibly associated with a tick bite in the index case, but which seems definitely to be transmitted quite efficiently via exposure to (presumably) body fluids, in a hospital setting…which does not appear to be known strains / types of Marburg or Ebola viruses, or Crimean-Congo haemorrhagic fever virus.

Loose in Johannesburg…part of a greater conurbation housing some 9 million people….

Should we be worried??

And the answer would be – NO.

If Ebola didn’t spread out of Kikwit in 1995 – a city of 500 000+ with no decent infrastructure to speak of – even to get as far as Kinshasa, then why should it spread in Johannesburg, or even Lusaka, where the infrastructure is MUCH more sophisticated?

I will leave this with a couple of quotes from posts I compiled on Ebola back in August 1995 from the fondly-remembered virology group at bio.net:

“To: virology@net.bio.net
From: ED@molbiol.uct.ac.za (“Ed Rybicki”)
Subject: Re: The Ebola virus – the end of the civilized world
Date: 18 Aug 1995 05:53:07 -0700

I would say you – and many others – are being unnecessarily
frightened by a concerted media campaign designed at selling lurid
books and films.  Listen – for a change – to what experts tell you,
and react accordingly.

That is, RELAX!!!!!”

And:

“To: virology@net.bio.net
From: york@mbcrr.harvard.edu (Ian A. York)
Subject: Re: Ebola: the greatest threat, continued

In article <99792FA2E69@ida.ruc.dk>,  wrote:
>
>Ebola is another ballgame. There is no way to protect effectively
>against this disease, and we have seen at mutation of this virus, Ebola
>Reston, that evidently was airborn (luckily it only affects monkeys).


Ebola has killed less than 400 people in the past decade.  By contrast, typhoid fever kills over 600,000 people per year; measles kills 1,000,000 (one million) people per year.  If you think Ebola has the potential tokill anywhere near that many, you don’t understand the virus.  The Ebola outbreak in Kikwit *was* the worst-case scenario; *everything* went wrong.  300 deaths.  Not trivial.  But a tiny fraction of the real killers. 

Lobby and try to get measles vaccine in Africa, if you want to do some good.  So don’t waste your time worrying about Ebola.”

Amen to that!  Pity we have to keep revisiting The Threat From Darkest Africa – maybe we can sell the rest of the world some vaccines against them sometime soon…B-)


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