A new study reveals the genetic identity of human immunodeficiency virus (HIV), the version responsible for sexual transmission, in unprecedented detail.
The finding provides important clues in the ongoing search for an effective HIV/AIDS vaccine, said researchers at the University of Alabama at Birmingham (UAB). The UAB team found that among billions of HIV variants only a few lead to sexual transmission.
Earlier studies have shown that a ‘bottleneck’ effect occurs where few versions of the virus lead to infection while many variants are present in the blood. The UAB study is the first to use genetic analysis and mathematical modeling to identify precisely those viruses responsible for HIV transmission.
On the 25th anniversary of the first scientific article linking a retrovirus to AIDS, Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases, reflects on his experience treating and studying HIV/AIDS for the past quarter century.
Outlining the peaks and valleys of the scientific community’s journey so far, Dr. Fauci writes, “…we must learn from our mis-steps, build on our successes in treatment and prevention, and renew our commitment to developing the truly transforming tools that will one day put this scourge behind us.”
From the outset, AIDS was clearly more menacing than any other novel disease Dr. Fauci and his colleagues had previously encountered, he writes. The period when clinicians lacked the ability to diagnose and treat AIDS was the bleakest of his career. The discovery that HIV causes AIDS stimulated a burst of progress in both the clinic and the laboratory. But the 1987 debut of the first effective drug against HIV, zidovudine (AZT), generated excessive optimism, Dr. Fauci reflects, as the virus quickly and predictably developed drug resistance.
Red colobus monkeys in a park in western Uganda have been exposed to an unknown orthopoxvirus, a pathogen related to the viruses that cause smallpox, monkeypox and cowpox. Most of the monkeys screened harbor antibodies to a virus that is similar – but not identical – to known orthopoxviruses.
The study was begun in 2006 when Colin Chapman, a researcher at McGill University, invited Goldberg to collaborate on a health assessment of two groups of red colobus monkeys in Kibale National Park, in western Uganda.
Chapman, also an associate scientist with the Wildlife Conservation Society, had spent two decades studying the behavior and ecology of the monkeys. He wanted to broaden the study to include an analysis of the pathogens they carried. Wildlife veterinarians from the Wildlife Conservation Society helped collect the samples, and a team from Oregon Health and Science University, led by Mark Slifka, conducted immunological analyses to characterize the virus.
Researchers from Washington University in St. Louis and the Israeli Institute of Technology (Technion) in Haifa have developed a technique called expected mutual information (EMI)to detect the ancestry of disease genes in hybrid, or mixed, human populations.
EMI determines how a set of DNA markers is likely to show the ancestral origin of locations on each chromosome. The team constructed an algorithm for the technique that selects panels of DNA markers that render the best picture of ancestral origin of disease genes. They then tested the algorithm to show that it is more powerful and accurate than standard algorithms that currently select for markers.
Scrapie can be transmitted to lambs through milk, according to new research published in BMC Veterinary Research. The study provides important information on the transmission of this prion-associated disease and the control of scrapie in affected flocks. Scrapie is a fatal neurodegenerative disease of sheep and goats.
Clinical signs include itchiness, head tremor, wool loss and skin lesions as well as changes in behaviour and gait.
Timm Konold and colleagues from the Veterinary Laboratories Agency in Weybridge, UK, investigated the transmission of scrapie by feeding milk from scrapie-affected ewes to lambs that are genetically susceptible to contracting scrapie. The researchers were looking for the presence of the prion protein, PrPd, which is associated with the disease.
The exchange of genetic material between two closely related strains of the influenza A virus may have caused the 1947 and 1951 human flu epidemics, according to biologists.
The findings could help explain why some strains cause major pandemics and others lead to seasonal epidemics. Until now, it was believed that while reassortment – when human influenza viruses swap genes with influenza viruses that infect birds – causes severe pandemics, such as the ‘Spanish’ flu of 1918, the ‘Asian’ flu of 1957, and the ‘Hong Kong’ flu of 1968, while viral mutation leads to regular influenza epidemics.
But it has been a mystery why there are sometimes very severe epidemics – like the ones in 1947 and 1951 – that look and act like pandemics, even though no human-bird viral reassortment event occurred.
A team of researchers at the University of Alberta, including a scientist at the University of Pennsylvania, have discovered a gene that is able to block HIV, and thought to in turn prevent the onset of AIDS.
Dr. Stephen Barr, a researcher in the Department of Medical Microbiology & Immunology at the U of A, says his team identified a human gene called TRIM22 that can block HIV infection in a cell culture by preventing the assembly of the virus.
Barr says “interestingly, when we prevent cells from turning on TRIM22, the normal interferon response (a natural defense produced by our cells to fight infection by viruses such as HIV) is useless at blocking HIV infection.
Deadly emerging diseases have risen steeply across the world and an international research team has provided the first scientific evidence mapping the outbreaks’ main sources.
New diseases originating from wild animals in poor nations are the greatest threat to humans and;
Expansion of humans into shrinking pockets of biodiversity and resulting contacts with wildlife are the reason.
Meanwhile, richer nations are nursing other outbreaks, including multidrug-resistant pathogen strains, through overuse of antibiotics, centralized food processing and other technologies.
Zoonotic pathogens passed from wildlife to people, from lowest occurrence (green) to highest (red).
In the work "Tractado contra el mal serpentino" written in 1510 and published in 1539, Ruy Diaz de Isla refers to have cured, during the travel of return in Europe, many members of the shipment of Columbus, affections from certain luetic manifestations and thinks the new disease was imported from Hispaniola (Haiti).
Bartolomè de Las Casas had conceived the same opinion. In the "Historia de Las Indias" he wrote as between the Conquistadores the idea of the "bestiality" of the wild Americans was prevalent and the disease would have been known already previously in the New World.
Moreover the most modern historiography places the accent on the instrumentalization of this idea to the ends of the colonial enslavement. The aborigines: lustful, inferiors, "homuncoli" (De Oviedo), naturally needy of being converted and to receive, therefore, with the faith also the slavery.
A University of Alberta study recommends that workers on pig farms be monitored as part of influenza pandemic preparedness, after a child on a communal farm in Canada was diagnosed with swine flu in 2006.
Though the seven-month-old boy made a full recovery, health researchers were concerned because of evidence that the virus spread to other members of the multi-family community, who, fortunately, all demonstrated mild or no apparent illness. It has been known for a long time that avian and swine strains of flu can spread to humans, with avian strains appearing to be more dangerous than swine strains; as of late 2007, the avian flu had killed 194 people in 321 cases reported worldwide.