Given that the bandwidth here in South Africa is so sadly lacking, I have refrained from doing what my less byte-challenged colleagues elsewhere do with gay abandon: yes, MicrobiologyBytes and virology blog, I speak of you!
However: given that a local newspaper saw fit to ask me about flu and other vaccines, and put up a podcast, I shall link to it from here. A little abridged – so you can’t tell what we are actually working on – but not too bad (my wife tells me).
From News24 this evening:
SA’s H1N1 deaths now 27
2009-09-01 17:03
Cape Town – The number of swine flu deaths in South Africa has risen to 27, and confirmed infections to 5 841, the National Institute for Communicable Diseases said on Tuesday.
“There is also ongoing and widespread community transmission,” it said in a statement.
Of the 27 fatal cases, 12 were pregnant women, five of whom had no identified underlying conditions.
The institute repeated its standard warning that people with depressed immunity, asthma, diabetes, or chronic lung, kidney and heart problems, or who were pregnant should seek early treatment with antivirals.
and on 26th August:
SA wants own H1N1 flu vaccine
2009-08-26 22:29
Cape Town – South Africa has no choice but to develop its own H1N1 flu vaccine, Health Minister Aaron Motsoaledi said on Wednesday, citing concerns treatment will not be available to poorer nations.
“South Africa has arrived at a situation where we have no option but to start developing our own vaccine capacity, not only for H1N1, but generally,” Motsoaledi told parliament.
“The disturbing feature about today’s world… has been expressed by the minister of health for Cambodia… who noted that the developed world, after producing the vaccine, may want to cover their own population first before thinking about the developing world,” Motsoaledi said.
Anyone remember reading that before, anywhere? Watch this space….
And after a very pleasant holiday, I come back to work to find…85 cases of confirmed pandemic H1N1 in South Africa!
Yes, it is true – at least, as far as the National Institute for Communicable Diseases (NICD) Director, Prof Barry Schoub, is concerned: he was featured yesterday on eTV News explaining how it was all going. And it is “mild” according to him: it looks the same as standard flu, although most cases so far are due to people bringing it into the country, without much community spread…yet.
In an article just published by the Independent Online (IOL), Kanina Foss says:
Swine flu cases will probably spike when schools reopen next week. Health officials will monitor schools, but are still advising that mild cases should be treated no differently from seasonal flu.
Only patients with serious symptoms – such as high fever, persistent vomiting, pain in the chest, or shortness of breath – should seek medical assistance. These are symptoms that people would seek medical assistance for anyway, says National Institute for Communicable Diseases (NICD) deputy director Lucille Blumberg.
The number of confirmed swine flu cases in South Africa is 75 [since modified, see above]. Once this number reaches 100, the NICD will stop counting. It will focus instead on severe cases and those at high risk because of compromised immune systems, such as HIV-positive people. The institute will also monitor schools. Counting cases was resource intensive, said the NICD on Monday, and served no more purpose than counting cases of seasonal flu. The overwhelming majority of cases worldwide had been mild, and had required no special treatment.
The World Health Organisation (WHO) has said the spread of the H1N1 virus is inevitable, and the NICD is expecting many more South Africans will be infected. It is unsure how the country’s high HIV prevalence will affect the severity of infections.
“It’s something we need to monitor very carefully,” said Blumberg.
The highest number of confirmed cases are in Gauteng (39), followed by the Eastern Cape (nine), and Western Cape (five).
Oh, and in my other persona, a post on AIDS denialism….
Yes, H1N1 “Mexico” flu is in South Africa: from the Mail & Guardian of 18th June.
H1N1 flu virus in the country, the Department of Health said on Thursday.
Spokesperson Fidel Hadebe said the results of laboratory tests confirmed the case in the early hours of Thursday. [after apparently having shown signs of fever in Atlanta! – Ed R]
Hadebe said the patient, a 12-year-old child, arrived in South Africa from the United States on Sunday.The child had flu-like symptoms and was admitted to a private hospital on Monday morning.“The patient was kept in isolation and discharged after a few days in hospital. He is well and recovering in isolation at home,” he said.
“All contacts have been followed up and given necessary advice and treatment.”
The case was dealt with in accordance with the World Health Organisation and the health department guidelines, Hadebe said.
More details were not immediately available.
…
Last week, the World Health Organisation declared the outbreak a pandemic. – SapaLatest news on the global front from ProMED:
As of 07:00 GMT+2 today [22 Jun 2009], there have been a total of 52 160 cases with 231 deaths attributable to influenza A(H1N1) infection confirmed to WHO from 92 countries. New countries that have confirmed cases and reported to WHO since the last update (19 Jun 2009) include: Algeria, Bangladesh, Brunei Darussalam, Fiji and Slovenia.
In addition, according to newswires, new countries reporting cases since the release of the daily WHO summary include Antigua and Iran.
There are still newswires mentioning confirmation of 2 cases of H1N1 in Ethiopia, but official confirmation to WHO is still pending. In addition, there are newswires mentioning suspected cases in Cote d’Ivoire and the Democratic Republic of the Congo (Kinshasa), but until there is mention of laboratory confirmation, these should be viewed as suspected cases and not confirmed cases. – Mod.MPP
So it’s in Africa for sure, and probably quite widespread. In the Nature issue of the 11th June, Erika Check Hayden had this to say concerning the southern hemisphere flu season which is presently upon us:
People in poor nations already suffer from a higher incidence of conditions, such as malnutrition and HIV, that make them more vulnerable to the new virus. In addition, they are likely to be left out of the global scramble for a vaccine, which has already started as nations such as the United States and Britain rush to tie up vaccine contracts.
But perhaps the biggest global challenge is arriving now, as the Southern Hemisphere enters its flu season and swine flu threatens many of the least-ready countries. “In general, the developing countries are not prepared,” Oshitani says. The World Bank has released billions of dollars for preparedness in these regions, but many developing nations still do not have plans for dealing with a pandemic — and some that do have simply cut and pasted versions of plans from developed countries, which do not apply to poorer nations unable to afford vaccines and antivirals.
Which is nothing new to readers of this blog…but alarming all over again.
Good news – potentially – comes from the realms of vaccine pharming: at the Plant-Based Vaccines and Antibodies meeting in Verona recently, Marc-Andre D’Aoust of Medicago Inc and Vidadi Yusibov of Fraunhofer USA detailed how they had managed to produce pilot batches of several grams of purified pandemic H1N1 HA protein from plants, in less than a month from obtaining the sequence.
I know I’d eat the plant directly, if it’d keep the flu away – but that’s just me. Don’t try this at home…!
From ProMED this morning:
INFLUENZA A (H1N1) – WORLDWIDE (60): EGYPT (CAIRO)**************************************************
A ProMED-mail post
Date: Tue 9 Jun 2009
Source: Angola Press Agency (Angop) [in French, trans. Mod.FE, edited]The influenza A (H1N1) virus has been detected in 2 foreign students of the American University of Cairo while [another 140 students] have been placed in quarantine, as we learnt from the medical services and the establishment.
Police officers wearing masks were stationed in front of their university dormitory in the Zamaleck area between the 2 arms of the Nile. Nobody was allowed either to go in or to come out.
“Two students were confirmed positive for the H1N1 virus. Consequently, the residence was placed under quarantine for 24 hours,” a representative of the university declared, adding that a 3rd student who had fever, had been hospitalized for precautionary motives. All the students shall be subjected to a screening test.
The 1st Egyptian case of influenza A was detected last Tuesday [2 Jun 2009]. It is a 12-year-old American girl who arrived on holiday in Cairo. It is equally the 1st case detected in Africa.
Communicated by: ProMED-mail
[This is an update providing some details of the 1st case of influenza A (H1N1) in Egypt and Africa as a whole. Despite all the awareness of this novel virus raised in the last month in most countries in the world, it seems the disease is spreading steadily across the globe.
This new outbreak is particularly concerning as there is concurrent circulation of H5N1 virus in both human and poultry populations, increasing the pathways by which a highly transmissible and high mortality virus could evolve. [EPR: my bold]
ProMED-mail will be interested in the sequence of events following the detection of cases of influenza A (H1N1) in Egypt. – Mods.FE/PC]
And so it begins…. While a lot of people are eagerly watching the unfolding, essentially in real time, of what MUST be termed a pandemic whether the WHO wants to call it that or not, there is a very real human element to this unfolding phenomenon.
That is, a LOT of people in Africa and elsewhere in the developing world will get sick – and many may die, whether or not this is a “mild” flu. Declan Butler, writing in the 27th May online version of Nature, says this:
“With the influenza season over in the temperate Northern Hemisphere, and just getting under way on the other side of the world, scientists are watching the A(H1N1) swine flu virus to see where it goes next and whether it will reassort with other flu viruses, or mutate, to cause more severe disease or acquire resistance to antiviral drugs.
Some researchers are warning, however, that such changes might be more likely to occur not in the northern or southern temperate zones where flu is seasonal, but in the narrow, often-overlooked belt of tropical countries where flu circulates all year round.”
And later:
“Surveillance is not just academic; it is key to getting early warnings of events that call for swift adaptations of control strategies. Swine flu is currently sensitive to the antiviral drug oseltamivir (Tamiflu), for example, but seasonal H1N1 is resistant. Were the new virus to acquire resistance, that would render redundant the Tamiflu stockpiled by many nations as part of their pandemic plans.
Tropical countries may be pivotal in such changes. “Tropical zones are the black box of influenza,” says Antoine Flahault, dean of the French School of Public Health in Rennes and Paris. Tropical southeast Asian countries in particular are a hotbed of flu viruses, ranging from H9N2 in children in Hong Kong and China, to H6N1 in birds and, by far the most prevalent, H4N6 in ducks and other waterbirds. The threat of reassortments occurring in poor tropical countries is compounded by the fact that humans tend to live in close proximity with livestock. “If it reassorts, who knows what could result,” says Shortridge.”
What a pleasant prospect…! As for the sociopolitical side, the WHO is holding off declaring this to be Stage 6 of a pandemic – for who knows what reason, given that human-to-human sustained chains of transmission have been amply demonstrated outside of the place of origin.
Debora MacKenzie, writing in the 22nd May issue of New Scientist, says the following:
“The WHO rules for declaring different degrees of flu pandemic threat are based on epidemiology (how the virus is spreading) for good reasons. This is because any new flu virus to which most of the world has little immunity, and which spreads well enough person-to-person to escape its continent of origin, is very likely to go global, and to cause more sickness and death than flu usually does. That is the definition of a flu pandemic.
The virus’s ability to spread is what matters. H5N1 bird flu has travelled across Eurasia, mainly in birds, but it hasn’t spread readily in people, so it isn’t a pandemic.
The Mexican swine flu H1N1, however, has. When it spread across the Americas, the WHO followed its rules and declared it a level 5 situation; one down from a pandemic. When it starts spreading outside the Americas, through “community transmission” – meaning it crops up generally, not just in people who have visited Mexico or New York recently or their contacts – that means it’s got a foothold globally.
A flu that can do that is very unlikely to stop there. The WHO rules make that a full-blown level 6 pandemic.
And frankly, that is starting to happen. As I write, the number of confirmed cases in Japan (and that’s just people sick enough to see a doctor and get tested) has jumped by 35 in the past 24 hours, to nearly 300, mostly due to that perennial vector of flu, the gregarious teenager. The main cluster started without any known links to the Americas.
Meanwhile in Europe, countries are deliberately not testing cases that could be community acquired – almost as if someone doesn’t want to trigger level 6.”
I wonder why…. Global economic meltdown, possibly? We watch and wait. Meantime, the last word from New Scientist again – from an editorial in the June 6th issue:
Just do the swine flu tests
06 June 2009GREEK doctors and flu scientists are saying what New Scientist revealed two weeks ago: swine flu could be spreading round Europe undetected because people without known links to flu aren’t being tested (see “Europe should test more broadly for swine flu”).
Maybe countries worry that if they test, they’ll be forced to use precious antiviral medicines on a mild strain. Maybe they just want this virus to spread quietly, so people will become immune to its successors. Maybe a basic understanding of epidemiology is lacking, though that seems unlikely.
But we know one thing: the only item of faith you need in science is that it’s better to know than not to know. If Europe’s leaders want everyone’s trust – trust they will need if this virus really does go global – it should emulate Australia, and do the tests.”
Amen.
I am indebted to Ms Ngimezi Phiri – muli bwanji! – in the MCB2016F class, to whom I have just lectured Virology, for pointing this out – from Yahoo! News:
“Scientists identify new lethal virus in Africa
By MIKE STOBBE, AP Medical Writer – Thu May 28, 9:15 pm ETATLANTA – Scientists have identified a lethal new virus in Africa that causes bleeding like the dreaded Ebola virus. The so-called “Lujo” virus infected five people in Zambia and South Africa last fall. Four of them died, but a fifth survived, perhaps helped by a medicine recommended by the scientists.
It’s not clear how the first person became infected, but the bug comes from a family of viruses found in rodents, said Dr. Ian Lipkin, a Columbia University epidemiologist involved in the discovery.
“This one is really, really aggressive” he said of the virus.
A paper on the virus by Lipkin and his collaborators was published online Thursday on in PLoS Pathogens.”
Of course, regular readers of this blog will be familiar with the Zambian arenavirus discovered under tragic circumstances last October, and covered here as follows:
Now the agent has a name – albeit an unfortunate victim of political compromise; they are calling it “Lujo” after Lusaka (where it came from, sort of) and Johannesburg, where nearly everyone who got it was treated.
The (relatively) rapid characterisation of the virus owes a lot to modern technology: in the words of the authors (MCB3019F take note – this is serious viromics…):
“RNA extracts from two post-mortem liver biopsies (cases 2 and 3) and one serum sample (case 2) were independently submitted for unbiased high-throughput pyrosequencing. The libraries yielded between 87,500 and 106,500 sequence reads. Alignment of unique singleton and assembled contiguous sequences to the GenBank database … using the Basic Local Alignment Search Tool (blastn and blastx; …) indicated coverage of approximately 5.6 kilobases (kb) of sequence distributed along arenavirus genome scaffolds: 2 kb of S segment sequence in two fragments, and 3.6 kb of L segment sequence in 7 fragments (Figure 2) [see here for depiction of arenavirus genome]. The majority of arenavirus sequences were obtained from serum rather than tissue, potentially reflecting lower levels of competing cellular RNA in random amplification reactions.”
Sequence data was used to allow primer synthesis for cDNA PCR to fill in gaps, and the whole genome is now available. It is a novel arenavirus, with all genome segments giving the same sort of phylogenetic tree topology, which shows the virus to be near the root of Old World arenaviruses.
The authors conclude:
“To our knowledge is LUJV the first hemorrhagic fever-associated arenavirus from Africa identified in the past 3 decades. It is also the first such virus originating south of the equator (Figure 1). The International Committee on the Taxonomy of Viruses (ICTV) defines species within the Arenavirus genus based on association with a specific host, geographic distribution, potential to cause human disease, antigenic cross reactivity, and protein sequence similarity to other species. By these criteria, given the novelty of its presence in southern Africa, capacity to cause hemorrhagic fever, and its genetic distinction, LUJV appears to be a new species.”
Ex Africa, semper aliquid novi(rus)…B-)
Fro ProMED Mail today:
“To summarize the current situation, as of 6:00 AM GMT on 18 May 2009 there have been a total of 8829 cases and 74 deaths of influenza A (H1N1) infection officially reported to WHO coming from 40 countries, up from 8480 confirmed cases and 72 deaths from 39 countries yesterday (17 May 2009). Chile is the new country confirming cases through the WHO summary report. As of 18:00 GMT-4, there have been a total of 9372 cases and 79 deaths reported worldwide, with 14 countries in the Americas reporting cases. According to newswires, there has been the 1st confirmed case in Greece with a history of travel to the USA prior to onset. Newswires continue to demonstrate significant increases in confirmed cases in Japan during the past 24 hours.The USA has officially reported 5123 laboratory confirmed cases coming from 48 states (compared with 4714 cases from 47 states on 15 May 2009), and 5 deaths (all in individuals with pre-existing illnesses). Canada has reported 496 cases from 10 provinces with 1 death in an individual with pre-existing illness, unchanged from the 496 cases and one death reported from 10 provinces/territories on 15 May 2009.
For a map of reported confirmed cases, worldwide, as of 06:00 GMT 18 May 2009, see here”
– Mod.MPP
So it is NOT going away…and has a case fatality rate, from these numbers, of 0.84%. This is significantly higher than the ~0.2% quoted for annual flu epidemics – which, if they kill ~400 000 people per annum, must infect ~200 million people.
Meaning if this flu infects the same number of people, >1.6 million people may die, over and ABOVE the normal toll.
28th April 2009:
It just HAD to happen.
There was the world’s attention, focussed on H5N1 bird flu from Asia as The Next Big One – including doom and gloom pronouncements from right here (and here) – and of course, another flu comes from another source, in another location entirely. You can, however, as previously highlighted here in ViroBlogy, use Google “Flu Trends” to track it – and now Google Maps too (thanks, Vernon!).
Flu life cycle
So what do we know? On the 27th of April, the Mexican government admitted to some 150 deaths, and over 1600 people apparently infected, in an epidemic caused by an Influenza A H1N1 virus that appeared to be a reassortant of viruses from pigs, birds and humans. The virus has been dubbed “swine flu”; however, there is doubt as to whether it has been shown to even infect pigs, let alone been found in them, and it probably ought to be known as “Mexico Flu”. There is the problem, of course, that apparently parts of the virus – and the N1 gene in particular – are of Eurasian swine flu origin, so exactly where it comes from may be forever obscure.
As for current expert knowledge, the Centers for Disease Control and Prevention (CDC) and the World Health Organisation (WHO) have set up dedicated pages to track the potential pandemic – because that is what they are calling it.
The WHO has, as of the 27th April,
“…raised the level of influenza pandemic alert from the current phase 3 to phase 4.
Swine Flu: Understanding the WHO’s Global Pandemic-Alert Levels – Health Blog – WSJ via kwout
The change to a higher phase of pandemic alert indicates that the likelihood of a pandemic has increased, but not that a pandemic is inevitable.
As further information becomes available, WHO may decide to either revert to phase 3 or raise the level of alert to another phase.
This decision was based primarily on epidemiological data demonstrating human-to-human transmission and the ability of the virus to cause community-level outbreaks.
Given the widespread presence of the virus, the Director-General considered that containment of the outbreak is not feasible. The current focus should be on mitigation measures.”
All of which begs the questions: what IS it, and how BAD is it?? We know that by the 28th April, the virus had been confirmed in the USA (>40 cases), Spain, Canada, and according the the BBC, the UK, Brazil and New Zealand as well.
While financial markets are panicking , airlines are cancelling flights, and people in Mexico appear to be dying, people infected in the USA seem only to be getting ill, and then recovering.
The bad news is that the virus haemagglutinin – the H1 – is probably only distantly related to that of the currently circulating human variant, so the flu vaccines on release right now will be of only limited efficacy.
The good news – especially for Roche and GlaxoSmithKline – is that the antivirals Tamiflu and Relenza seem to work against the virus.
29th April 2009
The virus continues to spread: according to the WHO site,
“As of 19:15 GMT, 28 April 2009, seven countries have officially reported cases of swine influenza A/H1N1 infection. The United States Government has reported 64 laboratory confirmed human cases, with no deaths. Mexico has reported 26 confirmed human cases of infection including seven deaths. The following countries have reported laboratory confirmed cases with no deaths – Canada (6), New Zealand (3), the United Kingdom (2), Israel (2) and Spain (2).
….
WHO advises no restriction of regular travel or closure of borders. It is considered prudent for people who are ill to delay international travel and for people developing symptoms following international travel to seek medical attention, in line with guidance from national authorities.“There is also no risk of infection from this virus from consumption of well-cooked pork and pork products. Individuals are advised to wash hands thoroughly with soap and water on a regular basis and should seek medical attention if they develop any symptoms of influenza-like illness.
Of course, there is also the inevitable hype – and some humour (thanks, Suhail!):
With a byline reminiscent of the “Ebola Preston” which was coined to satirise the hype generated around the 1995 Ebola hype, we have
30th April 2009:
…so of course, I talk to a journalist; and of course, I shouldn’t have…! For an otherwise good article about pandemic preparedness in Africa [ignore the bit about no drug stockpile in South Africa, because apparently we have some], see here. South Africans: look at info on influenza at the National Institute for Communicable Diseases (NICD) in Johannesburg.
The WHO yesterday raised the level of influenza pandemic alert from the current phase 4 to phase 5. We owe the WHO Director-General, Dr Margaret Chan, for these comments:
“On the positive side, the world is better prepared for an influenza pandemic than at any time in history.
Preparedness measures undertaken because of the threat from H5N1 avian influenza were an investment, and we are now benefitting from this investment.
For the first time in history, we can track the evolution of a pandemic in real-time.”
From the BBC today:
In Mexico, the epicentre of the outbreak, the number of confirmed cases rose to 97 – up from 26 on Wednesday….
- The Netherlands confirms its first case of swine flu, in a three-year-old boy recently returned from Mexico. Cases have also been confirmed in Switzerland, Costa Rica and Peru
- The number of confirmed cases in the US rose to 109 in 11 states
- Japan reported its first suspected case of swine flu
- China’s health minister says that the country’s scientists have developed a “sensitive and fast” test for spotting swine flu in conjunction with US scientists and the WHO. The country has recorded no incidence of the flu yet.
- The WHO says it will now call the virus influenza A (H1N1).
And first prize for over-reaction of the year:
On Wednesday, Egypt began a mass slaughter of its pigs – even though the WHO says the virus was now being transmitted from human to human [and there is no evidence it was ever transmitted between pigs].
A fascinating new post from Science Daily – for which, thanks Vaibhav Bhardwaj – raises again the problem of just exactly what is (and what is not) a virus?
The article in question describes a fascinating three-way interaction between a virus, a parasitic wasp, and a caterpillar – with a virus which happens to be part of the germline of the wasp, gets injected into the caterpillar as a free genome, and modifies its immune system so as to tolerate the wasp’s eggs.
From the article:
“Researchers have known for about 40 years that some species of parasitoid wasps inject these viruses, known as polydnaviruses, into the body cavities of caterpillars at the same time that they lay their eggs in the caterpillars. Because these “virus-like particles” have become an integral part of the wasp genome, some researchers have suggested they should no longer be considered viruses.”
Funny thing: that hasn’t stopped the International Committee on Taxonomy of Viruses (ICTV) from recognising as viruses agents such as Petunia vein clearing virus, a pararetrovirus (=DNA retrovirus) with an activatable integrated form, Banana streak virus, which is present in and activatable from the genomes of most Musa species, or even two whole families of retrovirus-like retrotransposable elements in the Pseudoviridae and the Metaviridae.
So there is ample precedent for things that integrate into host genomes, that are also viruses – including, among vertebrates, where activatable endogenous retroviruses are the subject of much study – including a finding that prions may activate endogenous retroviruses in the human brain.
And what of polydnaviruses (family Polydnaviridae)? Well, fascinating and unique beasts, these: the two genera so far described – Bracovirus and Ichnovirus – contain viruses which have a variable number of circular double-stranded DNA components, with components ranging in size from 2 to >31 kbp, for a total genome size between 150 – 250 kbp. Both sets of viruses occur as integrated proviruses in the genomes of endoparasitic hymenopteran wasps, replicate by amplification of the host DNA, followed by excision of episomal genomes by site-specific recombination, and only produce particles by budding from (ichnoviruses) or lysis of (bracoviruses) calyx cells in the oviducts of female wasps during pupal-adult transition. Moreover, the viruses in the two groups may well not be evolutionarily linked to one another, given that there is no antigenic or genome similarity, and the particles formed by the two groups are very different: ichnoviruses make ellipsoidal particles with double membranes containing one nucleocapsid; bracoviruses make single-enveloped particles containing one or more cylindrical nucleocapsids. The latter may derive from nudiviruses, which appear to have contributed very substantially to wasp survival.
From another Science Daily article:
“What this means… is that nudiviruses infected wasps a few million years ago and that, over time, the viral DNA fully integrated into the wasp genome. As it currently stands, the wasps need the virus to survive, because the virus helps the insects lay eggs in caterpillars. The virus also needs the wasp to survive, because the virus can only replicate in the wasp’s ovaries. The virus cannot replicate inside the caterpillar, because all of its replication machinery is inside the wasp.”
Particles are injected along with eggs into larvae of lepidopteran hosts; the DNA gets into secondary host cells and is expressed, but does not replicate -and this expression leads to some quite profound phsiological changes, many of which are responsible for successful parasitism. The association between wasp and virus has been termed an “obligate mutualistic symbiosis”, and appears to have evolved over more than 70 million years. It does nothing for the lepidopterans, however….
But nothing in this association would lead me to doubt their nature as viruses. Viruses now dependent on a particular host, maybe, but there now appears to be a continuum in the virus life experience, from massive bigger-than-cell-genome mimiviruses, through parasitic viruses to tiny circoviruses – and including agents that have become irretrievably integrated into the genomes of other hosts, yet still have a partially independent existence, like pseudoviruses – and polydnaviruses.
Viruses are wonderful…B-)
OK, time’s up…and we have – a 50% winner!! Clayton, you got 1 and 4 spot-on; Dorian, you got 1 and 4 generically correct. Answers are:
See now, that wasn’t so hard, was it?
And the prize is…Clayton, you get to write a guest blog on the virus(es) of your choice!! And we have ways and means of finding you, so I would do it if I were you…B-)
Thanks all (well, both) of you for entering; I will do this more often.
ViroBlogy 