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April 11, 2010)
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Friday, April 9, 2010
A discovery about the way
HIV attacks the immune system could pave the way for the development of new
treatments, scientists said.
Researchers have
identified a new method in which the human immunodeficiency virus, which causes
Aids, is able to prevent tetherin - a protein found naturally in human cells -
from doing its job of blocking the invaders.
Previous studies have
shown how viral protein U (Vpu) helps the spread of HIV in cells by inducing
degradation of tetherin.
But a team based in
Dr Eric Cohen, lead author
of the study - published in PLoS Pathogens - said further examination of the
process could help scientists find new drugs.
He concluded:
"Further characterisation of this mechanism will improve our understanding
of host antiviral defences as well as provide new targets for the development of
novel anti-HIV drugs."
Dr Marc Oullette,
scientific director of the Canadian Institutes of Health Research's
"This is a very
important finding by Dr Cohen's research team."
The mechanism deployed by
Vpu to assist the spread of HIV identified in the study can be likened to police
officers not being able to attend an incident, according to Dr Adriano Boasso,
an immunologist at Imperial College London.
He said tetherin is
rendered "useless" if it is not able to get to the surface of the cell
to perform its barrier function against infection.
08 Apr 2010
[
The new vaccine protects
against Streptococcus pneumoniae which causes pneumonia and, when it invades the
bloodstream and brain, causes septicaemia and meningitis.
Adults in the
The new conjugate vaccine
was tested using nearly 500 HIV-infected adults who had recovered from a bout of
pneumococcal disease. Three quarters of the patients remained free from the
disease, according to the researchers at the Malawi-Liverpool-Wellcome Trust
Clinical Research Programme, based at the University of Malawi College of
Medicine.
The vaccine worked even
when the number of CD4 cells in a patient's blood — an indicator of immune
strength — was less than 200, the level that indicates AIDS.
Unlike the polysaccharide
vaccine the new conjugate vaccine contains a protein that helps the body's
immune system recognise the pneumococcus bacteria, said Neil French, of the
Liverpool School of Hygiene and Tropical Medicine, in the
"The general view on
the use of any vaccine in HIV is that low CD4 counts make the vaccine useless.
We've shown that conjugate technology overcomes the profound immune deficiency
at these low counts. This gives hope for the possible use of conjugate
technology in other vaccines targeting important HIV associated bacterial
infections, most notably non-typhoidal Salmonella," he said.
"If conjugate
vaccines are found to confer protection against invasive pneumococcal disease,
this will be a major breakthrough, to reduce the morbidity and mortality of HIV
infected persons from pneumococcal disease," said French.
Jeremiah Chakaya, a chest
specialist at the Kenya Medical Research Institute welcomed the vaccine but said
it will only be a breakthrough when the price — US$40 — is brought down.
"If the cost of the
conjugate vaccine is about US$40 per dose, then it is going to be very difficult
for most African governments to purchase it, and even if they do, then the
people who need it will have to buy it at a very high price. This would make the
vaccine a preserve of the few rich people in the countries."
09 Apr 2010
Guardian Technologies International, Inc. (OTCBB: GDTI) announced that it has
joined forces with two prominent industry leaders in laboratory solutions, Prior
Scientific and Olympus Soft Imaging , to create and accelerate the integration
of Guardian's Signature Mapping™ (SM TBDx™) diagnostic software into a
first-of-its-kind, fully automated sputum microscopy solution for the
computer-aided-detection of tuberculosis.
A Memorandum of Understanding (MOU) between Guardian, The Aurum Institute for
Health Research (Aurum), and the South African National Health Laboratory
Services (NHLS) established the objectives and product specifications to address
the diagnostic challenges faced in
SM TBDx's 92.86% accuracy in positive cases and 3.75% false positive field of
views, in the November 2009 clinical trials, far exceeded the NHLS program
objectives of 80% accuracy and no more than 20% false positives, as well as
industry norms of less than 70% accuracy.
SM TBDx's exceptional performance prompted a request by NHLS to additionally
address the growing challenge of sputum slide processing and diagnostic
throughput, an ever increasing challenge in
The fully integrated SM TBDx system to be delivered initially to
"For decades, the world has needed a more accurate, low cost, fast TB
diagnostic solution -- particularly one that can accurately diagnose early stage
TB and TB in HIV-positive patients -- in centralized laboratories and at the
point of care. Guardian's Signature Mapping TBDx is the answer," said Rich
Borrelli, VP of Business Development for Guardian's Health Division. "The
product offerings of the SM TBDx fully automated and manual retrofit systems
position Guardian to address the full range of diagnostic environments.
Furthermore, SM TBDx's advanced image analysis integrated with automation
positions Guardian to immediately address the worldwide crisis in TB
detection."
The enhanced requirement of NHLS for the fully automated diagnostic solution
delayed the Phase 2 (final) clinical trial in
Guardian is currently in negotiations for the sale and deployment of the initial
three systems in
The fully automated slide management and detection system has major implications
for TB programs in heavily burdened countries like
To further penetrate the world TB diagnostic market, Guardian's SM TBDx product
offerings will be expanded to provide diagnostic solutions at large centralized
laboratories or hospitals (fully automated system), smaller local laboratories
in rural areas (retrofit system), and mobile labs to provide 100% screening of
the population in the most remote of areas.
VIEWPOINT
Dr Marika Davies
Medicolegal adviser, Medical Protection Society (MPS)
If a patient presents with
a sexually transmitted disease, how far do you go to protect their partner?
In this week's Scrubbing
Up, medico-legal expert Marika Davies explores the problems that might arise
from having a couple as patients.
Recent media coverage of
the illicit affairs of celebrities such as Mark Owen, John Terry and Tiger Woods
has focused extensively on the impact on those involved, but there can also be a
knock-on effect for those in whom the cheating partner may confide.
Patients involved in
extra-marital affairs often turn to their GPs for help with problems such as
sexually transmitted infections (STIs), unwanted pregnancies, or simply because
they see them as a confidante.
Doctors are bound by a
strict duty of confidentiality, as set out by their regulatory body, the General
Medical Council (GMC), but this can put them in a very difficult position,
especially if they are also responsible for the care of the partner who is being
cheated on.
For example, what if a
patient has an STI that he has contracted through an illicit affair, about which
his wife is unaware? She may be at risk, so does the GP have an obligation to
inform her?
The GMC states that
patients have a right to expect that information about them will be held in
confidence by their doctors.
Keeping confidences
Only in exceptional
circumstances can a doctor consider breaching this duty, for example where a
failure to disclose the information could lead to a risk of serious harm to
others.
It is clearly in the
public interest for patients to be able to seek confidential medical advice and
treatment, particularly in cases of communicable diseases.
“ One GP practice found
themselves in difficulties when they received a laboratory result showing that a
patient had tested positive for chlamydia. ”
Referring your patient to
a sexual health clinic for further treatment is the best course of action, as
the clinic will be able to carry out contact tracing and ensure that those who
may be at risk can be treated.
Although the clinic will
not disclose the identity of the patient, it may lead to difficulties for the
family doctor who is confronted by an irate partner wanting to know why they
have been contacted by the sexual health clinic. In one case a woman found an
appointment card for the clinic in her husband's pockets.
She demanded that her GP
tell her why her husband had been referred there, and put her under a great deal
of pressure to provide an explanation.
The GP handled the
situation well, and advised the wife that she could not tell her anything about
her husband without his consent. She also suggested to the wife that she should
attend the sexual health clinic for a check-up herself. Care needed
One GP practice found
themselves in difficulties when they received a laboratory result showing that a
patient had tested positive for chlamydia.
The receptionist left a
message on the patient's home telephone number informing her that a prescription
was waiting for her at the practice.
Unfortunately, her husband
picked up the message, came to the practice and was handed the prescription
along with an information leaflet on chlamydia that the GP had helpfully
attached to the prescription.
There was a clear breach
of the wife's confidentiality - the practice apologised and carefully reviewed
its procedures.
“ Doctors may be
uncomfortable knowing about the extra-marital activities of their patients, but
confidentiality is a key part of the doctor-patient relationship ”
Another doctor contacted
the MPS for advice about a patient who had been diagnosed HIV positive, and who
was adamant in his refusal to inform his wife, despite the doctor's best efforts
to persuade him to do so.
Under the particular
circumstances of this case, and in compliance with GMC guidelines, the doctor
considered it necessary to breach his patient's confidentiality and inform the
wife, in order to protect her from a risk of serious harm.
Doctors must be vigilant
even many years down the line, as the duty of confidentiality continues even
after a patient has died. A GP recently sought advice from MPS as she had been
contacted by a patient asking to see his deceased wife's medical records.
Reviewing the records, the GP noticed that the patient had had a termination of
pregnancy 30 years ago, next to which it was documented that her husband was
unaware. The doctor was advised by MPS that she should not disclose information
that the patient would have expected would be kept confidential.
Finally, spare a thought
for those doctors who are responsible for the care of celebrities in the media
spotlight, and who may come under intense pressure from the press or others to
disclose confidential information.
Intimate details of the
private lives of these patients may be splashed across the front pages, but they
are still owed the same duty of confidentiality by their doctors.
Doctors may be uncomfortable knowing about the extra-marital activities of their patients, but confidentiality is a key part of the doctor-patient relationship and is essential in ensuring that the public's trust in doctors will be maintained.
18 Mar 2010
Based on encouraging results from pre-clinical research, Bionor Immuno AS today
announced intentions to take the therapeutic and potentially preventative
HIV-vaccine candidate Vacc-C5 into a Phase I/II clinical trial. The research
results indicate that Vacc-C5 may induce a protective antibody response in HIV
patients similar to that found in patients with slow or non-progressing disease.
"The very slow or non-progressing HIV infection observed in a small
minority of patients, often referred to as 'controllers' because of their
ability to live symptom-free with HIV, has been the subject of academic interest
for years. The discovery of these antibodies in such patients could lead to a
significant shift in the approach to treating HIV. The results have been
presented to the Company's Clinical Advisory Board and with very encouraging
feedback," said Birger Sřrensen, CEO of Bionor Immuno.
Vacc-C5 is the second vaccine in Bionor's pipeline. Vacc-4x, acting by a
different mechanism (cell mediated immunity), has undergone a multi-centre
placebo-controlled Phase IIB trial with 134 HIV-patients who have temporarily
stopped taking daily ART. Results from the study are expected in October 2010.
Researchers Discover Vacc-C5 after Studying Immune Response of HIV Controllers
From research on blood donated by patients with a slow or non-progressing HIV
disease, the Company has identified a specific part of the virus, C5, which is
believed to induce hyper-activation of the immune system. Researchers believe
that the antibodies to C5 are likely to be protective and cause a slow disease
progression. Using its proprietary platform technology, the Company has
developed Vacc-C5, which is designed to induce a similar antibody response to
the one discovered in patients with slow disease progression. Vacc-C5 has passed
pre-clinical research tests showing that it has the potential to induce the
desired antibodies.
Disease progression from HIV to AIDS is triggered by the hyper-activation of the
immune system. This hyper-activation overwhelms the immune system and gradually
causes a collapse in the immune system, leading to AIDS. Researchers hope that
Vacc-C5 will have the ability to stop or greatly slow this progression.
The antibodies induced by Vacc-C5 are expected to be beneficial at all stages of
HIV disease and can be used for both treatment and prevention. Vacc-C5 works by
halting the hyper-activation of the immune system, producing a dual effect; i)
slowing down or halting the disease progression and ii) significantly reducing
the production of the virus. These properties, in combination with the
properties of the Company's most advanced vaccine candidate, Vacc-4x, may form a
potent preventative HIV vaccine.
Clinical Trial Program Strategy
As part of the preparations for a Phase I/II clinical trial to be initiated in
Q2, 2011, the Company will carry out routine toxicity tests, to ensure the
safety of the Vacc-C5 components. The toxicology program is planned to be
completed by early 2011.
Following the decision to move Vacc-C5 forward towards clinical testing the
Company has placed an order with Bachem for the production of
pharmaceutical-grade vaccine components to be used in the upcoming trial.
The HIV-market
In 2008 the United Nations estimated 33.4 million people are living with HIV
globally, of which 2.14 million have access to highly effective treatment. The
latter have access to antiretroviral therapy at a cost of between US$12,000 to
$15,000 per year, per patient. Data monitor estimates the value of
antiretroviral sales in the seven major markets (
Source
Bionor Immuno
18 Mar 2010
While The Canadian Lung Association commends the federal government's recent
commitment to international tuberculosis (TB) control, it urges the government
to continue working with provincial and territorial partners to reduce alarming
rates of TB among Inuit, First Nations and Métis.
In January, the federal government announced $100 million in funding to fight
this deadly yet preventable disease internationally. The federal funding will be
distributed through the Canadian International Development Agency (CIDA) to TB
REACH, an international initiative managed by the Stop TB Partnership.
TB REACH will encourage the development and application of innovative,
ground-breaking and efficient techniques, interventions, and activities to
increase TB case detection, reduce transmission and help prevent the emergence
of drug-resistant forms of TB.
"This funding will continue to position
TB remains a massive global public-health problem, with nearly 9 million new
cases each year, according to the Stop TB Partnership, an international network
of organizations whose goal is to eliminate TB. The number of
multi-drug-resistant tuberculosis (MDR-TB) cases has reached record levels,
according to the World Health Organization.
In 2008, people born outside of
"With TB, there are no borders," says Ms. Borquez. "While
In
According to 2008 figures from the Public Health Agency of Canada, Canadian-born
non-Aboriginal and Canadian-born Aboriginal cases made up 13% and 21% of all
reported cases, respectively.
However, the TB rate in the Canadian-born Aboriginal group continues to be the
highest of the three - almost six times greater than the overall Canadian rate.
For Inuit, the rate of TB is 32 times the national average and 185 times the
average for Canadian-born non-Aboriginals, the group with the lowest case rate.
"It is simply not acceptable that rates of tuberculosis among First
Nations, Inuit and Métis people in
"We need to ensure that our strategy for combating this disease also
focuses on such social determinants as poverty and housing. We look forward to
partnering with the federal government to ensure that the domestic fight against
TB is diverse in scope and aggressive in effort to eradicate this formidable
disease."
The international slogan for 2010 World Tuberculosis Day is "On the move
against tuberculosis." World TB Day is held every year on March 24th to
mark the discovery of the cause of the disease.
The Canadian Lung Association is the secretariat for and a founding member of
StopTB
Source
The Canadian Lung Association
18 Mar 2010
New research conducted by the scientific director for VGTI Florida and his
colleagues at the
The study, published in the journal Nature Medicine, describes the pivotal role
of two molecules, PD-1 and IL-10, in impairing the function of disease-fighting
T-cells known as CD4 T-cells - a phenomenon that weakens the body's immune
system.
Specifically, the researchers found that when HIV invades the body, bacterial
products are released from the gut and white blood cells respond by releasing a
protein on the surface of the cell called PD-1. Heightened levels of PD-1 lead
to the activation of a gene that produces another protein called IL-10. Both of
these proteins (PD-1 and IL-10) are known to appear at increased levels during
HIV infection.
"We are the first to show that these two molecules work together to shut
down the function of CD4 T-cells in HIV patients. This in turn, may lead to
paralysis of the immune system and an accelerated disease progression,"
said Dr. Rafick-Pierre Sékaly, scientific director of VGTI Florida, a professor
at the
"Our results suggest that it is important to block both IL-10 and PD-1
interactions to restore the immune response during HIV infection," said Dr.
Sékaly. "We believe that immunotherapies that target PD-1 and IL-10 should
be part of the arsenal used to restore immune function in HIV-infected
subjects."
About the study
The article "PD-1 Induced IL-10 Production by Monocytes Impairs CD4 T-Cell
Activation during HIV Infection," published in Nature, was authored by
Elias A. Said, Franck P. Dupuy, Lydie Trautmann, Yuwei Zhang, Yu Shi, Mohamed
El-Far, Brenna J. Hill, Alessandra Noto, Petronela Ancuta, Yoav Peretz, Simone
G. Fonseca, Julien Van Grevenynghe, Mohamed R. Boulassel, Julie Bruneau, Naglaa
H. Shoukry, Jean-Pierre Routy, Daniel C. Douek, Elias K. Haddad, and Rafick P.
Sekaly.
Source
VGTI
Michael Carter, Thursday,
April 08, 2010
Just over one-quarter of
patients taking modern antiretroviral therapy experienced virological failure
during a follow-up period of eight years,
“When considered against the background of a likely lifelong need for
antiretroviral therapy, these levels of resistance emergence are of some
concern,” comment the investigators.
Taking antiretroviral treatment can significantly improve the health and life
expectancy of patients with HIV. Such treatment is lifelong, and to obtain the
most benefit from anti-HIV drugs it is necessary to maintain suppression of the
virus. Increases in viral load can lead to the emergence of drug-resistant
strains of HIV.
The long-term rate of resistance, and the extent to which this differs according
to treatment combination, are crucial factors for understanding the long-term
efficacy of HIV treatment.
As both are uncertain,
All the patients took antiretroviral therapy that consisted of two nucleoside
reverse transcriptase inhibitors (NRTIs), plus either a ritonavir-boosted
protease inhibitor or a non-nucleoside reverse transcriptase inhibitor (NNRTI).
Virological failure was defined as two consecutive viral load measurements above
400 copies/ml six months after starting treatment. Tests were performed for four
types of resistance: TAMs, 1841V NRTI resistance, and resistance to protease
inhibitors or NNRTIs.
The study included patients who had started antiretroviral therapy after 1997,
and individuals were followed for eight years.
Most (82%) of patients started therapy with a regimen that included an NNRTI.
Tests performed before the initiation of treatment showed that 4% of individuals
had transmitted resistance to protease inhibitors or NNRTIs.
After eight years, 28% of patients had experienced virological failure, and 17%
of patients had some form of drug-resistant virus.
However, the risk of resistance differed between classes of antiretrovirals.
Treatment failure was significantly more likely to lead to resistance for
patients taking an NNRTI than a boosted-protease inhibitor (p < 0.001). This
finding remained unaltered when the investigators restricted their analysis to
patients who were taking recommended NRTIs.
Older age (p < 0.001) and female sex (p = 0.004) were both associated with a
lower risk of resistance.
By contrast, patients who started HIV treatment when their CD4 cell count was
below 200 cells/mm3 had an increased risk of resistance compared to individuals
who started treatment when their CD4 cell count was above the now-recommended
treatment initiation threshold of 350 cells/mm3 (p < 0.001).
In addition, a higher viral load at the time HIV treatment was started was also
associated with an increased risk of resistance. Individuals with a viral load
above 100,000 copies/ml were significantly more likely to develop resistance
than those with a viral load of 10,000 copies/ml or below (p = 0.03).
Patients who took efavirenz (Sustiva) were less likely to develop resistance (p
< 0.001) than those taking nevirapine (Viramune).
The investigators then restricted their analysis to the 33% of patients who had
had a genotypic resistance test before starting HIV treatment.
Resistance was detected in 11% of these patients. Virological failure occured in
22% of patients, and 14% developed resistance. Once again, the risk of
resistance differed between drug classes, and was detected in 15% of those
taking an NNRTI compared to 6% of individuals who received a boosted protease
inhibitor (p = 0.009). Other significant risk factors were the same as those
identified in the main analysis.
“In patients starting currently recommended first-line regimens in routine
clinical practice, the rates of virological failure and of resistance detection
are appreciable”, conclude the investigators, “the rates are lower for those
who started combination antiretroviral therapy with a ritonavir-boosted protease
inhibitor.”
An accompanying editorial praises the quality of the study, noting that it
“provides an important description of ‘where we are now’”. However, the
author suggests that the results should be interpreted with caveats, especially
as many of the NRTI pairs taken by patients in the study are no longer used in
routine HIV care.
Reference
Harrigan RP. HIV drug resistance over the long haul. Clin Infect Dis 50:
1286-87, 2010.
April 9, 2010 |
CBC News
Signals sent by the
attachment of HIV particles (shown as circles with spikes) result in barrier
cells (the rectangles) manufacturing inflammatory proteins (in red) that are
destructive to the cells' normally tight junctions, which create a protective
barrier. (Varun Anipindi/McMaster University)
HIV infects women by
weakening a cell barrier in the reproductive tract that normally keeps viruses
out, Canadian researchers have discovered.
HIV breaks down the tight
bonds between epithelial cells, which usually form a protective layer that
prevents viruses from infecting other cells.
This disintegration of the
epithelial cell barrier that lines the reproductive tract is what allows HIV to
be transmitted during intercourse, the researchers reported in this week's issue
of the journal PloS Pathogens.
Until now, scientists
thought HIV might enter the reproductive tract through a small tear. The new
findings suggest the response of epithelial cells to the virus itself might be
to blame.
Inflammatory
proteins made by the cells exposed to HIV weaken the tight junctions between
epithelial cells, making the barrier leaky and allowing HIV to get inside the
body and infect target cells. (Varun Anipindi/McMaster University)
"The important
implication here is that many of the preventative measures right now are focused
on preventing HIV from multiplying in the target cells that are in the tissue or
in the blood," said lead researcher Charu Kaushic, an associate professor
in the Centre for Gene Therapeutics at McMaster University in Hamilton.
"But our study
actually implies that that may be too late, because if the virus can get in, it
will eventually find target cells."
The findings suggest
scientists need to think of ways to stop HIV from attaching to the epithelial
cells themselves.
Unlike previous studies
that were based on cell lines from tumours that were manipulated, Kaushic's team
used uterine tissue taken from women who had hysterectomies, with their consent.
The epithelial cells were grown under conditions similar to those in the body,
which makes the results more reliable.
Weak barrier
Epithelial cells lining
the reproductive tract are designed to keep out infections.
But the researchers found
when HIV attached to epithelial cells, some of the inflammatory proteins made by
the cells became self-destructive. Instead of acting as a protective barrier,
the epithelial cells became leaky, allowing the virus to enter, Kaushic said.
The same process occurs in
epithelial cells regardless of where they are found, which means the findings
should also apply to anal intercourse, though this wasn't tested.
Repeated laboratory tests
confirmed that when HIV was put on epithelial cells, their electrical resistance
went down, the researchers found.
Scientists could
potentially develop molecules to coat the areas of the cell where the virus
attaches or otherwise stop the leakiness and thereby prevent the virus from
getting past the epithelial layer.
In the meantime, "the
message is still the same: that you have to be responsible for your reproductive
health," Kaushic advised
"The bottom line is,
this study sort of says, 'Well, we really shouldn't be allowing the virus to
attach.' If you're using condoms, that's one simple way to prevent the virus
from ever getting into contact with the lining."
The research was conducted
in collaboration with researchers in the department of molecular genetics at the
The research was funded by
the Ontario HIV Treatment Network and the Canadian Institutes of Health
Research.
Not a single
mother-to-child HIV transmission occurred in
“No women in this study treated according to national guidelines transmitted
HIV to her children”, comment the investigators.
Antiretroviral treatment during pregnancy and labour, an appropriately managed
delivery, infant prophylaxis, and the avoidance of breastfeeding can reduce the
risk of mother-to-child HIV transmission to below 1%.
Danish investigators performed a retrospective study, which monitored the
characteristics of HIV-positive pregnant women, their treatment and care, and
the rate of mother-to-child transmission. The researchers analysed data from
1994 to 2008.
A total of 210 women were included in the study. They had a total of 255
pregnancies, giving birth to 258 infants. The annual number of births increasd
from seven in 1994 to 39 in 2006.
The majority (51%) of women were African. Before 1999, only 8% of women were
aware that they were HIV-positive before their pregnancy. However, this
increased to 80% between 2000 and 2008.
A total of eight women (eight before 1999) were diagnosed so late that their HIV
was not detected until delivery or after.
In the period after 2000, two-thirds of pregnancies were planned, a third with
the assistance of an HIV physician. Fertility treatment was provided to 14% of
women.
Overall 50% of women took antiretroviral drugs before pregnancy. The proportion
increased as HIV treatment improved, from just 11% before 1999 to 58% after
2000.
HIV treatment was started during the first 14 weeks of pregnancy by 18% of
women. Once again, a temporal trend was detected, the proportion increasing from
6% before 1999 to 19% in the period 2000 to 2008.
Antiretroviral therapy was started in the third trimester by 8%, and 7% never
received any anti-HIV drugs. The main reason for this was very late diagnosis,
but a small number of women refused treatment.
After 2000, nearly all women received triple-drug therapy, the preferred
regimens being AZT and 3TC with either lopinavir/ritonavir or nevirapine.
An intravenous dose of AZT during labour was provided to 91% of women. The main
factor associated with this treatment not being provided was late diagnosis.
Median CD4 cell count at the time of delivery was 444 cells/mm3. CD4 cell counts
were higher amongst women who started treatment before the fourteenth week of
pregnancy than those who initiated therapy later (p < 0.05).
Viral load was below 40 copies/ml at the time of delivery in 81% of women. Women
who had started therapy before week 14 of pregnancy were significantly more
likely to have a viral load of this level than those who started therapy later
(87% vs 71%, p = 0.02).
Only 5% of women had a viral load above 1000 copies/ml – the threshold
associated with a significant risk of transmission – at the time of delivery.
Before 2000, 84% of infants were delivered by caesarean section. However,
between 2007 and 2008, 46% of women opted for a planned vaginal delivery.
A total of six infants were infected with HIV, providing an overall rate of
2.4%. This fell from 10% before 1999 to 0.5% in the period 2000 to 2008.
Five of the HIV-infected babies were delivered vaginally. None of the mothers
received antiretroviral therapy.
In addition, four of the women were diagnosed so late that it was not possible
to provide them with a dose of AZT during delivery.
One women who was unaware of her HIV infection until after delivery started
breastfeeding.
“Mother-to-child transmission decreased from 10.4% in 1994-1999 to 0.5% in
2000-2008. In each case, the mother was diagnosed with HIV either during or
shortly after delivery and none received antiretroviral therapy”, comment the
investigators.
They add that there was only one case of vertical transmission in the period
after 2000 and “no woman treated according to national guidelines transmitted
HIV to her child.”
Reference
von Linstow ML et al. Prevention of mother-to-child transmission of HIV in