News (Updated
December 12, 2010)
[Home]
[Previous
news]
Dec 8 2010
By Kate Kelland
LONDON (Reuters) - The
World Health Organization (WHO) gave its backing on Wednesday to a new molecular
test for tuberculosis made by Cepheid which can rapidly diagnose TB, one of the
world's biggest killer diseases.
The Geneva-based WHO said
in a statement it was endorsing the test because it could
"revolutionize" TB care and control by accurately diagnosing patients
in about 100 minutes, compared to current tests that can take up to three months
to give results.
Cepheid said it would
offer a 75 percent price discount for poorer nations on the tests and the table
top computer system used to analyze them, meaning the tests will cost $16.86 and
the machine will cost around $17,000.
The firm's chief executive
John Bishop told Reuters this preferential price would be granted to 116 low and
middle-income countries where TB is endemic, and prices would be discounted
further as the volume of demand rises in coming years.
The test, called Xpert MTB/RIF,
was developed by Cepheid and the Foundation for Innovative and New Diagnostics
(FIND), a non-profit group funded by the Bill & Melinda Gates Foundation,
the European Union and national donors. It detects many TB cases missed by
current technology, which is more than a century old.
"There has been a
strong commitment to remove any obstacles, including financial barriers, that
could prevent the successful roll-out of this new technology," said Giorgio
Roscigno, FIND's chief executive. "For the first time in TB control, we are
enabling access to state-of-the-art technology simultaneously in low, middle and
high income countries."
GROWING GLOBAL PROBLEM
TB hits mostly poor people
in developing regions such as sub-Saharan Africa,
It is among the world's
top 10 leading causes of death. The WHO estimates that 9.4 million people
developed active TB in 2009 and the disease killed 1.7 million in that year. The
emergence of drug-resistant and extensively drug-resistant forms of TB is also a
growing global problem.
Many countries still rely
largely on sputum smear microscopy for testing for TB, a diagnostic method
developed more than 100 years ago. The new Xpert MTB/RIF is a
"while-you-wait" test that can be used outside of conventional
laboratories by general health workers and does not require a specialist
operator.
In a study published in
September, researchers said that when used on 1,730 patients with suspected TB
and suspected drug-resistant TB, the Xpert test successfully identified 98
percent of all cases.
It also identified 98
percent of patients with a form of TB resistant to rifampin, or rifampicin --
one of the most powerful TB drugs -- and achieved these results in less than two
hours.
The WHO said
implementation of this test could result in a three-fold increase in the
diagnosis of patients with drug-resistant TB and a doubling in the number of
HIV-associated TB cases diagnosed in areas with high rates of TB and HIV.
Mario Raviglione, director
of the WHO's Stop TB department said the test represented "a major
milestone" for TB care.
The Xpert system, which
Cepheid expects to sell to wealthy nations too at full price, can also be used
to diagnose a number of other illnesses, including flu, leukemia, sexually
transmitted infections, and the so-called "superbug" MRSA.
Dec 7 2010
In a study of more than
1,800 men from the
Over the study period, 5
percent of the 1,365 uncircumcised men became HIV-positive, as did 4 percent of
the 457 circumcised men, according to findings published in the journal AIDS.
All of the men in the
study reported having sex with other men and were considered to be at increased
risk of HIV infection because they were already infected with the genital herpes
virus (herpes simplex type 2), which can make people more susceptible to HIV.
Male circumcision is far
more common in the
The researchers did find
some hints that circumcision could be protective among men who primarily had
insertive sex with other men. Among men who said they'd had insertive sex with
their last three male partners at least 60 percent of the time, circumcision was
linked to a 69 percent lower HIV risk.
That difference, however,
was not statistically significant, which means the finding could be due to
chance.
Taken together, the
results "indicate no overall protective benefit from male
circumcision" when it comes to male-to-male HIV transmission, write the
researchers, led by Dr. Jorge Sanchez of the research organization Impacta Peru,
in Lima.
They add that studies
should continue to look at whether circumcision affects HIV risk from insertive
sex and do so in larger, more diverse study groups.
In general, the
researchers write, public-health messages for gay and bisexual men should
"reinforce the importance of condom use for HIV prevention."
The findings may help
inform debate over whether circumcision could stand as a weapon against HIV
transmission among men who have sex with men.
In 2005 and 2006, three
clinical trials in
The World Health
Organization now recommends medically supervised circumcision as one way to
lower men's risk of HIV in countries where heterosexual transmission is common.
But the public-health
value of circumcision in other countries, including the
Circumcision is thought to
lower the heterosexual transmission of HIV and other sexually transmitted
diseases through several mechanisms. One is by reducing the amount of mucosal
tissue exposed during sex, which limits the viruses' access to the body cells
they target. Another theory is that the thickened skin that forms around the
circumcision scar helps block the viruses' entry.
One reason circumcision
might have little effect on homosexual HIV transmission is that it would have no
impact on the risk from receptive anal sex. Experts have also pointed out that
in wealthier countries, many HIV-positive people are on powerful anti-viral
drugs that reduce the risk of transmission, and any added effect of circumcision
might be small.
Currently, the
SOURCE: link.reuters.com/qaz88q
AIDS, online November 19, 2010.
GeoVax is developing two
vaccine components: a recombinant DNA-vectored vaccine and a recombinant MVA-vectored
vaccine. Both produce non-infectious virus-like particles in the body of a
vaccine recipient. These non-infectious particles are designed to
"train" the immune system of the vaccinated person to recognize HIV
should the vaccinated person be exposed to the real virus. Both the DNA and MVA
vaccines induce humoral (antibody) and cellular (cytotoxic T cell) responses.
Antibodies have the potential to block virus before it infects cells. The
cytotoxic T cells have the potential to recognize and kill virus-infected cells.
The vaccine is designed to control clade B HIV infections. Clade B HIV is found
in North, Central and parts of South America,
"I like the
simplicity of using the MVA-vectored vaccine alone because it is a regimen that
could easily be taken forward for the world. The data from our Phase 1 clinical
trial and recent preclinical data obtained using a non-human primate model
support the use of this simplified vaccine regimen," said Harriet Robinson,
the GeoVax Chief Scientific Officer.
The expanded Phase 2a
trial is sponsored by the National Institute of Allergy and Infectious Diseases,
part of the US National Institutes of Health, and is conducted by the HIV
Vaccine Trials Network (HVTN). The HVTN is the largest worldwide clinical trials
network dedicated to the development and testing of HIV/AIDS vaccines. The trial
bears the same HVTN 205 designation as the original Phase 2a trial.