GENEVANews (Updated
December 13, 2009)
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WASHINGTON (Reuters) - An
HIV genetic stowaway that may have come from a related cat virus could help the
AIDS virus transmit and replicate in people,
Their finding, which has
implications for designing new drugs or a vaccine against the fatal and
incurable virus, may also shed light on how other viruses, such as swine flu,
spread from animals to people, experts said.
And it also may help
explain how an ancient virus came to cause the devastating 25-year-long pandemic
of AIDS.
Dr. Robert Bambara of the
University of Rochester Medical Center in
This little bit of genetic
material closely mimics a stretch of human RNA, they reported in the journal
Nature Structural and Molecular Biology.
"We not only found
the gene, but also a plausible explanation for why it is still there after
millions of generations: its presence makes HIV dramatically better at
reproducing inside of our cells," Bambara said in a statement.
"This suggests new
ways to shut down with drugs the ability of the virus to mass produce copies of
itself."
HIV is believed to have
jumped to humans from a close relative called simian immunodeficiency virus or
SIV, which infects chimpanzees.
"Feline
immunodeficiency virus (FIV), which infects cats, is thought to be the virus
from which SIV originated and therefore an ancestor of HIV," the
researchers wrote.
"HIV-related viruses
have been identified in sheep, goats, horse, cattle and cats, but only the cat
virus FIV seems to be a close relative of HIV and SIV."
The gene Bambara's team
found looks very much like human tRNALys, which HIV needs to replicate itself.
Like all viruses, HIV "lives" by infecting cells, hijacking their
machinery and turning them into factories that make copies of the virus.
"Determination of the
origin of the tRNA-like sequence should provide valuable clues about the
ancestry of HIV," the researchers wrote.
Studying this genetic
sequence more may help scientists understand how viruses jump from animals to
humans, added Matthew Portnoy of the National Institute of General medical
Sciences, one of the National Institutes of Health.
The study "has
broader implications beyond HIV research, and may impact the response to the
current H1N1 flu pandemic, where that virus has jumped multiple species and
picked up several parts of its genome from each of the many species it has
passed through," Portnoy said in a statement.
"Understanding the
mechanisms of these transfers enables researchers to better understand the
evolution of viruses, and hopefully to better predict their 'next move' as they
design vaccines and treatments," Portnoy said.
HIV now infects an estimated 33.4 million people, according to the United
Nations, and has killed 25 million. H1N1 swine flu is still spreading globally
and has infected tens of millions.
10 Dec 2009
Source: IRIN
WHO recently recommended
http://www.who.int/mediacentre/news/releases/2009/world_aids_20091130/en/index.html
no longer using stavudine because of its long-term, irreversible side-effects,
including a condition called lipodystrophy, which causes fat loss from the face,
buttocks and limbs. The health body advised countries to instead adopt
zidovudine (AZT) or tenofovir, both less toxic and equally effective ARVs.
The Kenyan government will
adopt WHO's recommendations, but officials say the switch will have to be slow
due to logistical and financial hurdles.
"We are going to
change [but] it will be gradual... we'll mobilize resources," National
AIDS/STI Control Programme Kenya head, Nicholas Muraguri, told journalists in
the capital, Nairobi, on 9 December.
Muraguri said the
government was already working on a new protocol for first-line ARVs based on
the new guidance, but current stavudine stocks would continue to be administered
until a new supply of alternatives was ordered and delivered.
"There are
limitations on how fast one can get drugs," he said. "The government
has to book early, we have to guarantee [payment] a year before and tell the
manufacturer we intend to put a certain number of people on tenofovir, for
example."
He noted that once the
government fully adopted the new guidelines, funding requirements for the drugs
would likely double to about US$162 million per year because both AZT and
tenofovir were more expensive than stavudine; currently, the government spends
about $267 per patient every year on drugs for the 300,000 people on ARVs.
A 2008 study http://journals.lww.com/jaids/Fulltext/2008/07010/Cost_and_Cost_Effectiveness_of_Switching_From.14.aspx
in
Muraguri urged people on
stavudine not to panic and default on their daily drug taking on account of
WHO's new guidelines, as this could lead to the development of resistance.
"[Stavudine] works
and is effective... only 20 to 30 percent of patients develop
side-effects," he said.
Patients concerned
HIV-positive activist
Bethwel Nyangweso, who has been on a stavudine-based regimen for the past seven
years, expressed concern about WHO's new warnings.
"When I learnt of the
WHO guidelines I was irritated, but the doctor assured me there was no cause for
alarm," he said. "One of my fears is switching to AZT, which is
anaemia-causing; to me this is more serious than lipodystrophy," Nyangweso
said.
But for Grace Wairimu,
lipodystrophy was very serious; put on a stavudine-based regimen three years
ago, she developed side-effects such as a bloated abdomen and thinning buttocks.
"I wondered what was
happening... and my doctor switched me to zidovudine in place of stavudine,"
she said.
However, her new regimen
continues to give her problems. "I still have more and worse
side-effects... I am numb in the legs and hands, experience nausea and loss of
balance at times; I was better off with the stavudine," she added.
According to James Batuka,
HIV treatment team leader for USAID in
Dec 8, 2009
GENEVA
"With 87 percent of
treated patients being cured, the 85 percent global target was exceeded for the
first time," said the UN health agency, explaining that the latest data
related to treatment dated to 2007 as a delay of six months is required to
verify if a patient has indeed been cured.
The WHO also warned that
the current pace of progress was "far from sufficient" to meet the
target of eliminating the contagious disease.
Some 9.8 million TB cases
were recorded in 2008. About 1.8 million people died in the year from the
disease, including half a million deaths associated with HIV.
Drug resistant strains of
the TB bacteria are also infecting 500,000 people a year, but only 6,000 were
receiving treatment according to WHO standards in 2008.
Mario Raviglione, who
heads the WHO's Stop TB department, pointed to a two billion dollar shortfall in
funding and warned many more could miss out on the needed treatment.
"Without help to fill the two billion dollar funding gap for TB care and control in 2010, the most vulnerable people will continue to miss the benefits so many others have seen," he said.
Dec 7 2009
By Tan Ee Lyn
CANCUN, Mexico (Reuters) -
In Uganda, health experts are getting laboratories ready and preparing villagers
in two districts for a large clinical trial to test the world's first
experimental tuberculosis vaccine in nearly a century.
For Anne Wajja, a doctor
who heads TB vaccine studies in
"New TB drugs and
vaccines will be important, they will change the lives of ordinary people, it is
definitely important to have a new vaccine," said Wajja, who spoke at a
conference on lung health in
Over a thousand scientists
and researchers were gathered in
One of the oldest diseases
known to mankind, TB afflicts mostly the poor in developing places such as
sub-Saharan Africa,
For decades, it was
forgotten by richer and scientifically more advanced nations until people
infected with HIV started falling ill and dying from TB because of the damage
done to their immune systems by AIDS.
"It was only in the
80s and 90s when TB resurged in the west and north that everyone woke up and the
U.S. Congress asked 'this (TB) exists?'
TB Alliance is a
U.S.-based non-profit scientific group that pulls together partners to develop
new drugs to fight TB.
"So there is renewed
attention to the problem, and awakening and rebuilding again after many years of
lying fallow," Ginsberg said in an interview.
HOPES IN THE PIPELINE
Although TB has plagued
humankind for thousands of years, there is only one vaccine -- the Bacille
Calmette-Guerin (BCG) developed around 1920 -- which isn't very good.
It gives only some measure
of protection to young children and none at all to adults.
With the exception of
rifabutin, there has been no new drug for TB for more than 40 years.
Currently, patients need
to take a combination of four drugs daily for six to nine months and compliance
is poor, leading often to drug resistance. These patients then become harder to
treat because there are only very few second-line drugs.
One in every two patients
with the worst form of drug resistant TB dies.
There are now nine
experimental vaccines in clinical trials and experts in the field are confident
that the world will see a new and better vaccine by 2016.
The U.S.-based non-profit
Aeras Global TB Vaccine Foundation, which is working on four of the nine
vaccines, hopes to launch a product that will not only prevent TB infection in
all age groups, but also stop the TB bacteria from becoming active in people
infected with HIV.
"We think that
eventually we could prevent enough people from having the disease and acquiring
(the bacteria) that the transmission rate will be so low that the disease will
go away," said Aeras president Jerald Sadoff, a medical doctor.
TB Alliance is involved in
developing three of the eight experimental drugs in clinical trials, one of
which is moxifloxacin, which it hopes will be ready in five years.
"We are very hopeful
that moxifloxacin will be able to shorten treatment from six months to four
months," Ginsberg said.
Researchers are
considering using some of these experimental drugs in combination to prevent
drug resistance.
"We think some of
these novel combinations can bring treatment down to about three months because
they are completely new," Ginsberg said, adding that these new regimens can
be used for all TB patients, including those with drug resistant TB.
(Editing by Sandra Maler)
07 Dec 2009
Source: IRIN
Writing in the December
issue of the International Journal of STD (Sexually Transmitted Diseases) and
AIDS (IJSA), they argue that political expediency has motivated African
governments and international donor agencies to deliberately downplay the extent
of blood-borne infections because it has been easier to blame individuals and
their sexual practices than to take responsibility for ensuring safer
healthcare.
One study of HIV-positive
Swazi children aged between 2 and 12, which relied on data from the 2006-2007
Swaziland Demographic and Health Survey, found that one in five of the children
had HIV-negative mothers.
Discounting the
possibility that child sexual abuse could account for such a significant share
of paediatric infections, the authors suggested that contaminated needles used
to administer vaccinations and injections were to blame.
This argument was
supported by evidence from a Kenyan study, which found that HIV-infected
children with HIV-negative mothers had experienced more potential blood
exposures during malaria treatment, dental surgery and vaccinations than their
uninfected siblings.
The study has caused an
outcry in
Another study in the
journal published by the British Association of Sexual Health and HIV, found
that clients at voluntary HIV counselling and testing centres run by the
Writing about unsafe
medical injections in
They cite recent reports
indicating widespread lapses in infection control in public dental clinics, and
maternal and paediatric wards, and note that more than a quarter of individuals
detected in a 2005 national HIV prevalence survey as "recently infected
with HIV" said they had not been sexually active in the past 12 months.
The authors noted that if
a similar result had been found in a developed country, it would not have been
dismissed as respondents lying about their sexual histories, and would have
prompted further investigation.
Sexual transmission
over-stated
Commenting on the studies,
Moritz Hunsmann, a research scholar at the Paris Graduate School of Social
Sciences, wrote that "sexual behaviour is only part of the story, and
definitely an insufficient explanation for the dynamics of the epidemic spread
of HIV in sub-Saharan
He conceded that sexual
intercourse was probably the main mode of HIV transmission in sub-Saharan
Africa, and that strategies targeting behaviour change should play an important
role in prevention policies, but argued that the "fixation" on sexual
transmission was obscuring the need for improved blood screening and
sterilization of health equipment, while ensuring that public health authorities
were not held accountable.
Hunsmann asserted that
there were political incentives for keeping the extent of blood-borne HIV
infections "off the public agenda". "No doubt, African leaders
don't want their people to die from AIDS. But to what extent are those currently
in power willing to accept fundamental changes in the allocation of political
and economic resources in order to effectively address the epidemic's structural
drivers?"
Prof David Gisselquist, an
independent health and economics consultant, went even further in his paper on
double standards - one for rich countries and another for poor - in HIV research
ethics, healthcare safety and scientific studies. He alleged that
"withholding evidence pointing to ... [hospital acquired] HIV transmission
in
Dr Francois Venter,
president of the Southern African HIV Clinicians Society, was unimpressed.
"There are lots of alternative explanations [for sub-Saharan
Venter pointed out that
unsafe needle practices did not explain, for example, why relatively wealthy
countries like