Dramatic decline in new cases of orphanhood in Uganda driven by HIV treatment and prevention programs

Columbia University's Mailman School of Public Health

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The scale-up of HIV treatment and prevention programs has led to remarkable declines in orphanhood rates in Rakai, Uganda, according to a new study at Columbia University Mailman School of Public Health. Antiretroviral therapy (ART) availability has been the primary driver of these improvements, underscoring the critical importance of sustained investment in HIV programs. Findings from the study, " Incidence and prevalence of orphanhood in Rakai, Uganda: a population-based cohort study, 1995–2022" are published in The Lancet Global Health.  

 Using data from the Rakai Community Cohort Study (RCCS), one of the largest community cohort studies in sub-Saharan Africa, the research tracked 92,441 children and adolescents under age 18 years in 28 continuously surveyed communities from 1995 to 2022 to advance understanding of orphanhood trends in the context of evolving HIV programs.  

Between 2003–04 and 2020–22, orphanhood prevalence in Rakai declined dramatically from 21.5 percent to just 6.3 percent —a reduction of approximately 70 percent. Orphanhood incidence (new cases of becoming an orphan) showed an even greater decline.

The steepest declines occurred after ART became fully available (2015–22), compared to periods of partial availability (2004–14) and pre-ART era (1995–2003). The proportion of new orphanhood cases attributed to maternal HIV status plummeted from 67 percent in 2004 to just 11 percent in 2022. For parental HIV status, attribution declined from 71 percent to 12 percent over the same period. 

"The scale-up of antiretroviral therapy in Uganda has clearly played a leading role in the observed declines in orphanhood incidence, demonstrating the life-saving impact of comprehensive HIV treatment programs and treatment as prevention," said Aleya Khalifa, PhD, postdoctoral research scientist in the Department of Population and Family Health, and co-lead author "Importantly, these programs have not just extended the lives of parents living with HIV but have also protected children from the devastating social and health consequences of losing their parents," added Debbie Malden, DPhil and epidemiologist in the Columbia Population Research Center, and a co-lead author.

These findings provide compelling evidence for the effectiveness of widespread ART availability and the power of treatment as prevention in reducing orphanhood in sub-Saharan Africa, according to the authors. However, they emphasize that despite these gains, a considerable burden of orphanhood persists, particularly among adolescents. The study recommends that public health policies should ensure sustained investment in HIV treatment and prevention programs, improve accessibility of ART services, and adapt programming to address the ongoing vulnerability of children at risk of orphanhood. 

The Rakai Community Cohort Study was a collaborative research project among researchers at Columbia University Mailman School of Public Health, the Rakai Health Sciences Program, Imperial College London, The Alan Turing Institute, Johns Hopkins University, Makerere University, City University of New York, University of Oxford, and the Uganda Virus Research Institute.

Co-authors are John Santelli, Philip Kreniske Columbia University Mailman School of Public Health; Oliver Ratmann, Yu Chen, Imperial College London, London, and Johns Hopkins University;  Oliver Ratmann, Susan Hillis, The Alan Turing Institute, London; M. Kate Grabowski, School of Medicine, Johns Hopkins University, College of Health Sciences, Makerere University, Uganda; Larry  W. Chang, Rakai Health Sciences Program, Uganda and College of Health Sciences, Makerere University, Uganda;  A.F. Nalugoda, G. Kigozi, T. Lutalo, N. K .Sewankambo A Ndyanabo MSc, F Makumbi PhD, D Serwadda, R Ssekubugu, A. Ssettuba, H. Nakawooya, College of Health Sciences, Makerere University, Uganda, N. K. Sewankambo, F. Makumbi, CUNY Graduate School of Public Health and Health Policy; P. Kreniske, Makerere University School of Public Health, Uganda; F. Makumbi, D. Serwadda, The Global Reference Group for Children Affected by Crisis, University of Oxford; and S Hillis, Uganda Virus Research Institute, Entebbe, Uganda.

The study was supported by the National Institute of Allergy and Infectious Diseases, National Institute of Child Health and Development, Gates Foundation, National Institute of Mental Health, and National Institutes of Health Fogarty International Center.

Columbia University Mailman School of Public Health

Founded in 1922, the Columbia University Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Columbia Mailman School is the third largest recipient of NIH grants among schools of public health. Its nearly 300 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change and health, and public health preparedness. It is a leader in public health education with more than 1,300 graduate students from 55 nations pursuing a variety of master’s and doctoral degree programs. The Columbia Mailman School is also home to numerous world-renowned research centers, including ICAP and the Center for Infection and Immunity. For more information, please visit www.mailman.columbia.edu.

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Journal

The Lancet Global Health

Article Title

Incidence and prevalence of orphanhood in Rakai, Uganda: a population-based cohort study, 1995–2022

 

Higher intake of food preservatives linked to increased cancer risk

Findings may have important public health implications given the ubiquitous use of these additives, say researchers

BMJ Group

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Higher intake of food preservatives, widely used in industrially processed foods and beverages to extend shelf-life, is associated with a modestly increased risk of cancer, finds a study from France published by The BMJ today.

 

While further research is needed to better understand these links, the researchers say these new data call for the re-evaluation of regulations governing the use of these additives by the food industry to improve consumer protection.

 

Preservatives are substances added to packaged foods to extend shelf life. Some experimental studies have shown that certain preservatives can damage cells and DNA, but firm evidence linking preservatives to cancer risk remains scarce.

 

To address this, researchers set out to examine the association between exposure to preservative food additives and risk of cancer in adults, using detailed dietary and health data from 2009 to 2023.

 

Their findings are based on 105,260 participants aged 15 years and older (average age 42 years; 79% women) enrolled in the NutriNet-Santé cohort study who were free of cancer and completed regular 24 hour brand-specific dietary records over an average 7.5 year period. Health questionnaires and official medical and death records were then used to track cancer cases up to 31 December 2023.

 

A total of 17 individual preservatives were analysed including citric acid, lecithins, total sulfites, ascorbic acid, sodium nitrite, potassium sorbate, sodium erythorbate, sodium ascorbate, potassium metabisulfite, and potassium nitrate.

 

Preservatives were grouped into non-antioxidants (which inhibit microbial growth or slow chemical changes that lead to spoilage) and antioxidants (which delay or prevent food deteriorating by removing or limiting oxygen levels in packaging).

 

During the follow-up period, 4,226 participants received a diagnosis of cancer, comprising 1,208 breast, 508 prostate, 352 colorectal, and 2,158 other cancers.

 

Of the 17 individually studied preservatives, 11 were not associated with cancer incidence, and no link was found between total preservatives and cancer incidence.

 

However, higher intakes of several preservatives (mostly non-antioxidants including potassium sorbate, potassium metabisulfite, sodium nitrite, potassium nitrate, and acetic acid) were associated with higher risk of cancers compared with non-consumers or lower consumers.

 

For example, total sorbates, specifically potassium sorbate, was associated with a 14% increased risk of overall cancer and a 26% increased risk of breast cancer, while total sulfites were associated with a 12% increased risk of overall cancer.

 

Sodium nitrite was associated with a 32% increased risk of prostate cancer, while potassium nitrate was associated with an increased risk of overall cancer (13%) and breast cancer (22%).

 

Total acetates were associated with an increased risk of overall cancer (15%) and breast cancer (25%), while acetic acid was associated with a 12% increased risk of overall cancer.

 

Among antioxidant preservatives, only total erythorbates and specific sodium erythorbate were found to be associated with higher incidence of cancer.

 

While more studies are needed to better understand these potential risks, the researchers note that several of these compounds can alter immune and inflammatory pathways, possibly triggering the development of cancer.

 

This is an observational study, so no firm conclusions can be drawn about cause and effect, and the researchers can’t rule out the possibility that other unmeasured factors may have influenced their results.

 

However, they say this was a large study based on detailed dietary records linked to food databases over 14 years and results are consistent with existing experimental data suggesting adverse cancer related effects of several of these compounds.

 

As such, they conclude: “This study brings new insights for the future re-evaluation of the safety of these food additives by health agencies, considering the balance between benefit and risk for food preservation and cancer.”

 

In the meantime, they call on manufacturers to limit the use of unnecessary preservatives, and support recommendations for consumers to favour freshly made, minimally processed foods.

 

From a policy perspective, preservatives offer clear benefits by extending shelf life and lowering food costs, which can be particularly important for populations with lower incomes, point out US researchers in a linked editorial.

However, they say the widespread and often insufficiently monitored use of these additives, with uncertainties of their long term health effects, call for a more balanced approach.

Findings from NutriNet-Santé may prompt regulatory agencies to revisit existing policies, such as setting stricter limits on use, requiring clearer labeling, and mandating disclosure of additive contents, while collaborative global monitoring initiatives, similar to those implemented for trans fatty acids and sodium, could also support evidence based risk assessments and guide reformulation by the food industry, they write.

“At the individual level, public health guidance is already more definitive about the reduction of processed meat and alcohol intake, offering actionable steps even as evidence on the carcinogenic effects of preservatives is evolving,” they conclude.

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Journal

The BMJ

DOI

10.1136/bmj-2025-084917 

Method of Research

Observational study

Subject of Research

People

Article Title

Intake of food additive preservatives and incidence of cancer: results from the NutriNet-Santé prospective cohort

Article Publication Date

7-Jan-2026

COI Statement

All authors have completed the ICMJE uniform disclosure form at https://www.icmje.org/disclosure-of-interest/ and declare: support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme, French National Cancer Institute, French Ministry of Health, IdEx Université de Paris, and a Bettencourt-Schueller Foundation research prize 2021; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

Mass General Brigham–developed cholera vaccine completes phase 1 trial

Clinical trial shows promising results for PanChol, a single-dose oral vaccine aimed at the up to 4 million annual cholera cases worldwide

Brigham and Women's Hospital

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Clinical trial shows promising results for PanChol, a single-dose oral vaccine aimed at the up to 4 million annual cholera cases worldwide

A team of scientists and physicians at Mass General Brigham has developed a single-dose oral cholera vaccine and tested it in a phase 1 clinical trial, with results published in The Lancet Infectious Diseases.

“The devastating cholera outbreak in Haiti in 2010 triggered my desire to create a new oral live-attenuated cholera vaccine,” said co–senior author Matthew K. Waldor, MD, PhD, a principal investigator in the Division of Infectious Diseases in the Mass General Brigham Department of Medicine. “Existing vaccines made from inactivated bacteria require multiple doses and are not that efficacious, particularly in young children, the population most at risk of dying from cholera. Our research on the cholera pathogen suggested ways to make improved vaccines. We hope our vaccine will be deployed where it is most needed to save lives—in places where cholera is endemic and during outbreaks.”

Up to 4 million cholera cases and 143,000 related deaths occur annually, with approximately 1.3 billion people at risk of disease, which is caused by ingestion of Vibrio cholerae bacteria in tainted water or food. These bacteria produce toxins that cause severe vomiting and diarrhea.

Waldor and his colleagues derived their new vaccine, called PanChol, from a weakened version of the Vibrio cholerae strain that is currently responsible for most global cholera cases. The group added certain characteristics to make the live vaccine safe and prevent it from regaining the ability to produce toxins and cause disease.

 In the 57-participant phase 1 trial, individuals received increasing doses of PanChol to identify the most effective dose. Based on these findings, additional participants were randomly assigned to receive either one oral dose of PanChol or one oral dose of placebo.

As the most important goal of a phase 1 trial is to ensure safety, Waldor and his collaborators were pleased to observe that adverse events were typically mild and transient. Whole-genome sequencing of PanChol isolated from vaccinated participants’ stool samples confirmed the vaccine’s genomic stability, which is needed to ensure its safety. PanChol shedding, a marker for vaccine replication in the intestine, was detectable across vaccine doses, and 100% of people who were vaccinated mounted strong immune responses against Vibrio cholerae antigens two weeks after vaccination.

"This work represents a significant step forward in our efforts to combat a devastating disease and shows what can be accomplished at MGB given the depth of our scientific talent,” said co–senior author Lindsey Baden, MD, vice president of clinical research at Mass General Brigham. “This achievement is a testament to the collaborative spirit among research scientists and clinical trial experts at Mass General Brigham who share a commitment to improving the lives of patients both here and globally.”

An important next step in PanChol development is to test the vaccine in places where cholera is endemic. To that end, an additional phase I trial of PanChol will be begin in Lusaka, Zambia sometime in early 2026.

Authorship: In addition to Waldor, Mass General Brigham authors include Deborah R Leitner (co-first author), Stephen R Walsh (co-first author), Masataka Suzuki, Michaël Desjardins, Alisse Hannaford, Amy C Sherman, Hannah Levine, Lena Carr, Elliot Hammerness, Akina Osaki, Emily Sullivan, Bryan Wang, George I Balazs, Jun Bai Park Chang, Damien M Slater, Nirajan Puri, Carole J Kuehl, Jason B Harris, Steven Piantadosi, and Lindsey R Baden (co-last author). An additional author includes Wilbur H Chen.

 

Disclosures: Waldor is an inventor on a patent related to PanChol. Additional author disclosures can be found in the paper.

Funding: This study is supported by a Wellcome Trust grant (218443/Z/19/Z) to Waldor and Baden. Waldor is supported by US National Institutes of Health (NIH) grant RO1AI042347-29 and the Howard Hughes Medical Institute. Baden is supported by US National Institute of Allergy and Infectious Diseases (NIAID) grant 5-UM1-AI-069412-19 and the Harvard Clinical and Translational Science Center (1UL1TR002541-01). Hannaford is supported by NIH T32 grant AI007061. Sherman is supported by NIH grant 1K23AI185318–01A1. Harris is supported by NIAID grant R01AI179917.

Paper cited: Leitner DR et al. “Safety and immunogenicity of PanChol, a single-dose live-attenuated oral cholera vaccine: results from a phase 1a, double-blind, randomised, placebo-controlled trial” Lancet Infectious Diseases DOI: 10.1016/S1473-3099(25)00682-6

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About Mass General Brigham

Mass General Brigham is an integrated academic health care system, uniting great minds to solve the hardest problems in medicine for our communities and the world. Mass General Brigham connects a full continuum of care across a system of academic medical centers, community and specialty hospitals, a health insurance plan, physician networks, community health centers, home care, and long-term care services. Mass General Brigham is a nonprofit organization committed to patient care, research, teaching, and service to the community. In addition, Mass General Brigham is one of the nation’s leading biomedical research organizations with several Harvard Medical School teaching hospitals. For more information, please visit massgeneralbrigham.org.

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Journal

The Lancet Infectious Diseases

DOI

10.1016/S1473-3099(25)00682-6 

Method of Research

Randomized controlled/clinical trial

Subject of Research

People

Article Title

Safety and immunogenicity of PanChol, a single-dose live-attenuated oral cholera vaccine: results from a phase 1a, double-blind, randomised, placebo-controlled trial

Article Publication Date

7-Jan-2026

COI Statement

Waldor is an inventor on a patent related to PanChol. Additional author disclosures can be found in the paper.

 

Dogs’ dinners can have greater climate impact than owners’

University of Edinburgh

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Dogs fed on premium, meat-rich pet food can have a bigger dietary carbon pawprint than their owners, according to the largest study into dog food’s climate impact.

In particular, wet, raw and meat-rich products are associated with substantially higher greenhouse gas emissions than dry dog food.

Overall, the production of ingredients used in UK dog food is estimated to contribute around one per cent of the country’s total greenhouse gas emissions.

The findings highlight the need for greater transparency and better labelling of dog food ingredients to help consumers make informed choices, as pet ownership continues to rise, experts say.

Scientists from the Universities of Edinburgh and Exeter used ingredient and nutrient labelling information to calculate the carbon footprint of almost 1000 commercially available dog foods, based on emissions generated during the production of ingredients. Their sample included a selection of dry, wet and raw foods, including plant-based and grain-free options.

Producing enough food of the types fed in the UK for all dogs worldwide could generate greenhouse gas emissions equivalent to over half of those from burning jet fuel in commercial flights each year, experts estimate.

The analysis also reveals striking differences in the environmental impact of commercial dog foods, with the highest impact foods responsible for up to 65 times more emissions than the lowest rating options.

Using large amounts of prime meat – which could otherwise be eaten by humans – pushes up emissions, whilst the use of nutritious carcass parts that are in low demand helps limit environmental impact.

Dry food, not marketed as grain-free, tended to have a lower environmental impact than wet, raw or grain-free options.

Dog owners who want to reduce environmental impacts but not change food type should check the label description of meat cuts used in the food, aiming for a lower content of prime meat, experts say.

An increase in the use of plant-based dog foods is also likely to reduce emissions. However, the research team caution that only a small number of plant-based foods were available to test for this study.

The study, funded by the Biotechnology and Biological Sci­ences Research Council (BBSRC), is published in the Journal of Cleaner Production: https://doi.org/10.1016/j.jclepro.2025.147277 [URL will become active after embargo lifts].

The study’s principal investigator, John Harvey, from the University of Edinburgh’s Royal (Dick) School of Veterinary Studies said: “As a veterinary surgeon working on environmental sustainability, I regularly see owners torn between ideals of dogs as meat‑eating ‘wolves’ and their wish to reduce environmental harm. Our research shows just how large and variable the climate impact of dog food really is. It’s important for owners to know that choosing grain-free, wet or raw foods can result in higher impacts compared to standard dry kibble foods. The pet food industry should make sure meat cuts used are of the types not typically eaten by humans, and that labelling is clear. These steps can help us have healthy, well-fed dogs with a smaller pawprint on the planet.”

For further information, please contact: Jess Conway, Press and PR Office, jess.conway@ed.ac.uk

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Journal

Journal of Cleaner Production

DOI

10.1016/j.jclepro.2025.147277