Posts Tagged ‘Lusaka’

Down, Lujo!

4 June, 2009

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 ET

ATLANTA – 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-)