People living with HIV who maintain low – but still detectible – levels of the virus and adhere to their antiretroviral regimen have almost zero risk of transmitting it to their sexual partners, according to an analysis published in The Lancet. The study’s findings will be presented at an official satellite session ahead of the 12th International AIDS Society Conference on HIV Science (IAS 2023).
Findings from the systematic review indicate the risk of sexual transmission of HIV is almost zero at viral loads of less than 1,000 copies of the virus per millilitre of blood-;also commonly referred to as having a suppressed viral load. The systematic review also confirms that people living with HIV who have an undetectable viral load (not detected by the test used) have zero risk of transmitting HIV to their sexual partners.
A new policy brief from the World Health Organization (WHO), published alongside the research paper, provides updated sexual transmission prevention and viral load testing guidance to policymakers, public health professionals, and people living with HIV based on this analysis. This guidance aims to further prevent the transmission of HIV and ultimately support global efforts to achieve undetectable viral loads through antiretroviral therapy for all people living with HIV and to prevent onward transmission to their sexual partner(s) and children.
Previous research has shown people living with HIV with viral loads below 200 copies/mL have zero risk of sexually transmitting the virus. However, until now, the risk of transmission at viral loads between 200 and 1000 copies/mL was less well defined.
The authors filled this knowledge gap by searching databases for all research studies published between January 2000 and November 2022 on sexual transmission of HIV at varying viral loads. In total, eight studies were included in the systematic review, providing data on 7,762 serodiscordant couples – in which one partner was living with HIV – across 25 countries.
These findings are important as they indicate that it is extremely rare for people who maintain low levels of HIV to transmit it to their sexual partners. Crucially, this conclusion can promote the expansion of alternative viral load testing modalities that are more feasible in resource-limited settings. Improving access to routine viral load testing could ultimately help people with HIV live healthier lives and reduce transmission of the virus.”
Laura Broyles, MD, Lead Author, Global Health Impact Group (Atlanta, USA)
Taking daily medicine to treat HIV – antiretroviral therapy, or ART – lowers the amount of the virus in the body which preserves immune function and reduces morbidity and mortality associated with the virus and helps reduce HIV progression. Without ART, people living with HIV can have a viral load of 30,000 to more than 500,000 copies/mL, depending on the stage of infection.
While using lab-based plasma sample methods provides the most sensitive viral load test results, such tests are not feasible in many parts of the world. However, the new findings support the greater use of simpler testing approaches, such as using dried blood spot samples, as they are effective at categorising viral loads for necessary clinical decision-making.
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Of the 323 sexual transmissions of HIV detected across all eight studies, only two involved a partner with a viral load of less than 1000 copies/mL. In both cases, the viral load test was performed at least 50 days before transmission, suggesting individuals’ viral load may have risen in the period following the test. In studies that provided the full range of viral loads in partners with HIV, at least 80% of transmissions involved viral loads greater than 10,000 copies/mL.
Co-author Dr Lara Vojnov, of WHO, said: “The ultimate goal of antiretroviral therapy for people living with HIV is to maintain undetectable viral loads, which will improve their own health and prevent transmission to their sexual partners and children. But these new findings are also significant as they indicate that the risk of sexual transmission of HIV at low viral loads is almost zero. This provides a powerful opportunity to help destigmatise HIV, promote the benefits of adhering to antiretroviral therapy, and support people living with HIV.”
The authors acknowledge some limitations to their study. Some of the data analysed were imprecise due to variations across the studies in the definitions of ‘low viral load’, and in the timing and frequency of viral load testing and patient follow-up. Today, HIV treatment is recommended for everyone living with HIV and very large sample sizes would be needed to develop more precise estimates given the extremely low number of transmissions.
Further, the findings do not apply to HIV transmission from mother to child, as the duration and intensity of exposure – during pregnancy, childbirth, and breastfeeding – is much higher. Differences also exist in the way the virus is passed from mother to child as compared with sexual transmission. Ensuring pregnant and breastfeeding women have undetectable viral loads throughout the entire exposure period is key to preventing new childhood HIV infections.
Writing in a linked Comment, co-authors Linda-Gail Bekker, Philip Smith, and Ntobeko A B Ntusi (who were not involved in the study) said, “Laura N Broyles and colleagues’ systematic review in The Lancet further supports the almost zero risk for sexual transmission of HIV at levels less than 1000 copies per mL…This evidence is relevant for at least three important reasons. First, it highlights the need for viral load testing scale-up in all settings where people are living with HIV and taking ART…Second, as pointed out by Broyles and colleagues, these data are probably the best that we will ever have. Standard of care now requires that individuals are offered life-saving ART regardless of viral load…Third, and most importantly, this study provides strong support for the global undetectable equals untransmittable (U=U) campaign. This campaign seeks to popularise the concept that individuals with undetectable viral loads are not infectious to sexual partners, thereby reducing stigma and improving quality of life.”
Journal reference:
Broyles, L. N., et al. (2023) The risk of sexual transmission of HIV in individuals with low-level HIV viraemia: a systematic review.The Lancet. doi.org/10.1016/S0140-6736(23)00877-2.
The Canadian government says it will donate up to 200,000 vaccine doses to fight the mpox outbreak in Congo and other African countries.
It says the donated doses of Imvamune will come from Canada’s existing supply and will not affect the country’s preparedness for mpox cases in this country.
Minister of Health Mark Holland says the donation “will help to protect those in the most affected regions of Africa and will help prevent further spread of the virus.”
Dr. Madhukar Pai, Canada research chair in epidemiology and global health, says although the donation is welcome, it is a very small portion of the estimated 10 million vaccine doses needed to control the outbreak.
Vaccine donations from wealthier countries have only recently started arriving in Africa, almost a month after the World Health Organization declared the mpox outbreak a public health emergency of international concern.
A few days after the declaration in August, Global Affairs Canada announced a contribution of $1 million for mpox surveillance, diagnostic tools, research and community awareness in Africa.
On Thursday, the Africa Centres for Disease Control and Prevention said mpox is still on the rise and that testing rates are “insufficient” across the continent.
Jason Kindrachuk, Canada research chair in emerging viruses at the University of Manitoba, said donating vaccines, in addition to supporting surveillance and diagnostic tests, is “massively important.”
But Kindrachuk, who has worked on the ground in Congo during the epidemic, also said that the international response to the mpox outbreak is “better late than never (but) better never late.”
“It would have been fantastic for us globally to not be in this position by having provided doses a much, much longer time prior than when we are,” he said, noting that the outbreak of clade I mpox in Congo started in early 2023.
Clade II mpox, endemic in regions of West Africa, came to the world’s attention even earlier — in 2022 — as that strain of virus spread to other countries, including Canada.
Two doses are recommended for mpox vaccination, so the donation may only benefit 100,000 people, Pai said.
Pai questioned whether Canada is contributing enough, as the federal government hasn’t said what percentage of its mpox vaccine stockpile it is donating.
“Small donations are simply not going to help end this crisis. We need to show greater solidarity and support,” he said in an email.
“That is the biggest lesson from the COVID-19 pandemic — our collective safety is tied with that of other nations.”
This report by The Canadian Press was first published Sept. 13, 2024.
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
HALIFAX – The Nova Scotia government says it could be months before it reveals how many people are on the wait-list for a family doctor.
The head of the province’s health authority told reporters Wednesday that the government won’t release updated data until the 160,000 people who were on the wait-list in June are contacted to verify whether they still need primary care.
Karen Oldfield said Nova Scotia Health is working on validating the primary care wait-list data before posting new numbers, and that work may take a matter of months. The most recent public wait-list figures are from June 1, when 160,234 people, or about 16 per cent of the population, were on it.
“It’s going to take time to make 160,000 calls,” Oldfield said. “We are not talking weeks, we are talking months.”
The interim CEO and president of Nova Scotia Health said people on the list are being asked where they live, whether they still need a family doctor, and to give an update on their health.
A spokesperson with the province’s Health Department says the government and its health authority are “working hard” to turn the wait-list registry into a useful tool, adding that the data will be shared once it is validated.
Nova Scotia’s NDP are calling on Premier Tim Houston to immediately release statistics on how many people are looking for a family doctor. On Tuesday, the NDP introduced a bill that would require the health minister to make the number public every month.
“It is unacceptable for the list to be more than three months out of date,” NDP Leader Claudia Chender said Tuesday.
Chender said releasing this data regularly is vital so Nova Scotians can track the government’s progress on its main 2021 campaign promise: fixing health care.
The number of people in need of a family doctor has more than doubled between the 2021 summer election campaign and June 2024. Since September 2021 about 300 doctors have been added to the provincial health system, the Health Department said.
“We’ll know if Tim Houston is keeping his 2021 election promise to fix health care when Nova Scotians are attached to primary care,” Chender said.
This report by The Canadian Press was first published Sept. 11, 2024.
ST. JOHN’S, N.L. – Newfoundland and Labrador‘s chief medical officer is monitoring the rise of whooping cough infections across the province as cases of the highly contagious disease continue to grow across Canada.
Dr. Janice Fitzgerald says that so far this year, the province has recorded 230 confirmed cases of the vaccine-preventable respiratory tract infection, also known as pertussis.
Late last month, Quebec reported more than 11,000 cases during the same time period, while Ontario counted 470 cases, well above the five-year average of 98. In Quebec, the majority of patients are between the ages of 10 and 14.
Meanwhile, New Brunswick has declared a whooping cough outbreak across the province. A total of 141 cases were reported by last month, exceeding the five-year average of 34.
The disease can lead to severe complications among vulnerable populations including infants, who are at the highest risk of suffering from complications like pneumonia and seizures. Symptoms may start with a runny nose, mild fever and cough, then progress to severe coughing accompanied by a distinctive “whooping” sound during inhalation.
“The public, especially pregnant people and those in close contact with infants, are encouraged to be aware of symptoms related to pertussis and to ensure vaccinations are up to date,” Newfoundland and Labrador’s Health Department said in a statement.
Whooping cough can be treated with antibiotics, but vaccination is the most effective way to control the spread of the disease. As a result, the province has expanded immunization efforts this school year. While booster doses are already offered in Grade 9, the vaccine is now being offered to Grade 8 students as well.
Public health officials say whooping cough is a cyclical disease that increases every two to five or six years.
Meanwhile, New Brunswick’s acting chief medical officer of health expects the current case count to get worse before tapering off.
A rise in whooping cough cases has also been reported in the United States and elsewhere. The Pan American Health Organization issued an alert in July encouraging countries to ramp up their surveillance and vaccination coverage.
This report by The Canadian Press was first published Sept. 10, 2024.
