NIAID-Funded Study Traces Evolution of Malaria Drug Resistance in E. Africa – Emergence of Artemisinin Partial Resistance Mutations Found Across Uganda

Emerging resistance to common malaria treatments in Uganda could be connected to inconsistent use of measures to control mosquito populations, according to new findings published in the New England Journal of Medicine. The trend is worrisome, the NIAID-funded scientists state, because resistance mutations they tracked are taking root and spreading. Researchers at the University of California at San Francisco (UCSF), funded in part by NIAID’s International Centers of Excellence for Malaria Research program, led the international collaboration.

Malaria is one of the most common and serious infectious diseases. The World Health Organization (WHO) estimates that about half of the world’s population is at risk of getting malaria, which is caused primarily by Plasmodium falciparum parasites spread through the bites of female Anopheles mosquitos. In 2021, WHO estimated that about 247 million people contracted malaria in 85 countries; about 619,000 people died. About 95% of cases and deaths were in Africa.

For decades a combination of measures has resulted in effective malaria control in Africa: preventing malaria transmission with bed nets treated with insecticides; spraying insecticides indoors; treating malaria with artemisinin-based combination medicines; and preventing malaria with other drugs.

Artemisinins – originally extracted from the sweet wormwood plant, but also now available synthetically – rapidly eliminate malaria parasites from the bloodstream. They are used in combination with other longer-lasting drugs to effectively treat malaria. Beginning in 2008, however, studies in Southeast Asia identified poor results from artemisinins and eventually from artemisinin-based combination malaria treatments. Scientists soon found the primary reason – a protein (PfK13) in P. falciparum had developed mutations that made it partially resistant to artemisinins.

Since then, scientists in Africa have watched for the same mutations to emerge. The NEJM study identified five of these mutations, each of which may lead to partial resistance, that have emerged in different parts of Uganda. Their work used data from malaria cases and annual patient surveillance throughout Uganda between 2014 and 2022.

They found that two of the five key mutations appeared in far northern Uganda in 2016-17. The mutations then spread across much of northern Uganda and nearby regions, appearing in up to 54% of cases in one district. The other three key mutations emerged in western Uganda in about 2021-22, with prevalence up to 20% to 40% in different districts.

The study notes that in parts of Uganda where indoor spraying stopped between 2014 and 2018, cases of malaria quickly surged. Likewise, the emergence of any of the five key resistance mutations also surged, suggesting that the emergence was aided by malaria epidemics in populations where malaria had previously been well-controlled.

The researchers have different theories about how and why the mutations emerged. Their leading hypothesis, which they have targeted for more study, is that in populations with a low level of immunity to malaria, an epidemic increases the likelihood that resistance will emerge. “In northern Uganda,” the study states, “this scenario occurred after the withdrawal of effective malaria control, leading to high incidence of malaria in a population with relatively low antimalarial immunity.” They also suggest that fluctuating malaria transmission contributed to the emergence of drug resistance in southwestern Uganda. They emphasize the importance of maintaining malaria control interventions, with attention to malaria outbreaks, to decrease the likelihood of emergence or spread of drug resistance.

Others working on the project with UCSF include scientists from the Infectious Diseases Research Collaboration and Makerere University in Uganda; the University of Tubingen in Germany; Brown University in Rhode Island; and Dominican University of California.

Reference: 

M Conrad et al. Evolution of Partial Resistance to Artemisinins in Malaria Parasites in Uganda. New England Journal of Medicine DOI: 10.1056/NEJMoa2211803 (2023).

Viral hepatitis is an inflammatory liver disease caused by infection with any of the known hepatitis viruses—A, B, C, D, and E. Most of the global viral hepatitis burden is from hepatitis B and C, which affect 354 million people and result in 1.1 million deaths annually. The Centers for Disease Control and Prevention estimates that in 2020 there were 14,000 and 50,300 new acute infections of hepatitis B and C in the United States, respectively, while at least 880,000 people in the country were living with chronic (long-term) hepatitis B and 2.4 million people had chronic hepatitis C. About half of those with viral hepatitis are unaware of their infection. Chronic and persistent inflammation from the disease can lead to liver failure, cirrhosis, or liver cancer. Viral hepatitis affects all ages and there are pronounced inequities in disease outcomes in the United States. Hepatitis B and C disproportionately affect people living with HIV, and HIV increases the rate of complications and death in people with viral hepatitis.

On this World Hepatitis Day, the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, shares a snapshot of its investments in basic (laboratory), preclinical (laboratory/animal), and clinical (human) research to improve screening, prevention and treatment for hepatitis B and C. Scientists in the Hepatic Pathogenesis and Structural Virology sections of NIAID’s Laboratory of Infectious Diseases conduct basic and translational research to better understand hepatitis B and C disease progression, clarify the role of hepatitis viruses in liver cancer, and inform discovery of new vaccines, medicine and technologies. Both NIAID’s Division of AIDS (DAIDS) and the Division of Microbiology and Infectious Disease (DMID) support scientific programs focused on hepatitis B and C research and curative strategies, reflecting the widespread impact of viral hepatitis and the urgent need for safe and effective interventions.

Finding a hepatitis B cure

Hepatitis B continues to cause disease and death even though a highly effective preventive vaccine has been available for decades. Some people with acute hepatitis B can naturally clear the infection. In others, chronic HBV requires lifelong treatment to suppress the virus. More research is need to identify novel therapeutic options and strategies to minimize the treatment burden and, ideally, identify a cure for hepatitis B. NIAID is supporting research on a variety of basic, translational and therapeutic science concepts designed to cure hepatitis B, including in people with HIV. DMID recently announced an initiative to develop new antiviral drugs that can eliminate hepatitis B genetic material from infected cells, and DAIDS is complementing that work with clinical studies of therapeutic agents and vaccines that will include evaluation of their safety and efficacy in people living with HIV.

Streamlining the hepatitis C response

In 2011, direct-acting antivirals (DAA) revolutionized hepatitis C therapy and have since been observed to cure 95% of cases. Despite DAA availability for more than a decade, only one in three people in the United States diagnosed with hepatitis C receive curative treatment. These circumstances underscore the importance of increasing access to and convenience of diagnosis and treatment, as well as the need for a preventive vaccine. Developing a hepatitis C vaccine is challenging because of the genetic diversity of hepatitis C circulating in the population, necessitating broadly reactive vaccine technology. DMID awarded multiple grants to advance new hepatitis C vaccine designs in 2021. To better enable people to know their hepatitis C status, NIAID and other NIH institutes are supporting discovery of improved point-of-care hepatitis C testing that could be used in community and healthcare settings alike, and eliminate the need to wait for laboratory-based diagnostics. They are also supporting development of self-testing technology that people can use to screen themselves. DAIDS will soon launch an initiative to develop long-acting DAAs that could reduce the number of doses required for a full course of therapy. A recent NIAID-supported study showed even with an existing 84-tablet DAA regimen, most people with hepatitis C experienced favorable treatment outcomes without in-person healthcare visits for the duration of treatment. These innovations in diagnostics and treatment strategies aim to enable a “single-encounter cure” wherein a person could learn their hepatitis C status and collect their treatment in one healthcare visit.

These research priorities are among the current efforts in NIAID’s 60-year pursuit of scientific advances to improve the health outcomes of people with viral hepatitis. For more information on US government research to help eliminate viral hepatitis, please visit:

• NIAID Diseases & Conditions: Hepatitis
• Trans-NIH Strategic Plan to Cure Hepatitis B
• Health and Human Services Viral Hepatitis National Strategic Plan

This blog is cross-posted from HIV.gov. 

On Tuesday at the International AIDS Society’s 12th Conference on HIV Science (IAS 2023), HIV.gov continued our conversations about research highlights, including a focus on the latest about HIV vaccines. We also heard an update from the NIH Office of AIDS Research.

NIH’s Carl Dieffenbach, Ph.D., Director of the Division of AIDS at the National Institute of Allergy and Infectious Diseases (NIAID), spoke with Louis Shackelford, M.P.H., about HIV vaccine studies being discussed at IAS 2023 and potential roles for broadly neutralizing antibodies (or bNAbs). Louis is the Acting Director for External Relations at the NIH-supported HIV Vaccine Trials Network (HVTN) and COVID-19 Prevention Network. Noting it is an exciting time in HIV vaccine research, Carl explained that scientists are exploring how to take what we have learned about bNAbs, which prevented acquisition of some HIV strains, and turn that into an HIV vaccine. In addition, Carl and Louis discussed how bNAbs are being studied for use in HIV treatment and even, possibly, a cure. View their conversation below:

Bill Kapogiannis, M.D., Acting Director of NIH’s Office of AIDS Research (OAR), spoke with Catey Laube, Section Chief for HIV, STIs, Allergy, Immunology, and Transplantation in NIAID’s Office of Communications and Government Relations. OAR coordinates the scientific, budgetary, legislative, and policy components of HIV/AIDS research across NIH’s institutes and centers. Bill discussed the importance of the results from the NIH-supported REPRIEVE trial presented yesterday at the conference. The global study found that statins, a class of cholesterol-lowering medications, may offset the elevated risk of cardiovascular disease experienced by people with HIV by more than a third, potentially preventing one in five major cardiovascular events (e.g., heart attack or stroke) or premature deaths in this population. He noted that these important findings have implications for clinical guidelines for the care of people with HIV. Bill also observed that the findings are relevant to two of OAR’s signature programs: HIV and Aging, since the study population was people with HIV ages 40-75, and HIV and Women, since the results were equally applicable to women. View their conversation below:

IAS 2023, convening in Brisbane, Australia, features the latest advances in basic, clinical, and operational HIV research and seeks to move science into policy and practice. The conference features seven plenary sessions, more than 60 symposia and oral abstract sessions, hundreds of poster sessions, and many satellite sessions featuring highly diverse and cutting-edge research. Many of the studies that are being presented have been conducted by or funded by federal partners, including NIH, CDC, PEPFAR, DoD, and others.

As is the custom in Australia, HIV.gov acknowledges the Jagera and Turrbal people as the Traditional Custodians of Meanjin (Brisbane), the land on which IAS 2023 is taking place. We pay our respects to Jagera and Turrbal elders past, present, and emerging.

Follow all of our conversations from IAS 2023 this week here on the blog as well as on on HIV.gov’s Facebook, Instagram, and Twitter, and on the LinkedIn account of the HHS Office of Infectious Disease and HIV/AIDS Policy.

This blog is cross-posted from HIV.gov.

During the first full day of sessions at the International AIDS Society’s 12th Conference on HIV Science (IAS 2023), HIV.gov shared conversations on important study findings about reducing cardiovascular disease among people with HIV and the latest developments with long-acting prevention and treatment options that could one day become safe and effective alternatives to daily oral pills.

NIH’s Carl Dieffenbach discussed findings presented today about the NIH-supported Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) trial, a global study that demonstrated a daily statin medication reduces the increased risk of cardiovascular disease experienced by people living with HIV. (Learn more in this NIH news release published today.) Dr. Dieffenbach is the Director of the Division of AIDS at NIH’s National Institute of Allergy and Infectious Diseases (NIAID). He spoke today with Molly Moon, M.S.W., Deputy Director of the NIH-supported Office of HIV/AIDS Network Coordination. They also discussed progress reported at IAS 2023 from several studies investigating long-acting HIV prevention and treatment options, including some that were presented in a plenary session that Carl chaired today. Carl summarized that long-acting options are moving toward better drugs with lower doses and longer durations. View their conversation below:

To learn more about what the results of the REPRIEVE trial mean, Molly also spoke with Steven Grinspoon, M.D., professor of medicine at Harvard University and chief of the metabolism unit at Massachusetts General Hospital, who led the REPRIEVE study. Steven highlighted that this global trial, involving participants in 12 countries, found that the use of the statin pitavastatin calcium reduced the risk of major adverse cardiovascular events—including heart attack, stroke, and cardiovascular death—among people with HIV by 35%. He added that the study found that the intervention was equally efficacious among men and women. Simultaneous to their presentation at IAS 2023, the REPRIEVE study findings were published in the New England Journal of Medicine.

IAS 2023, convening in Brisbane, Australia, features the latest advances in basic, clinical, and operational HIV research and seeks to move science into policy and practice. The conference features seven plenary sessions, more than 60 symposia and oral abstract sessions, hundreds of poster sessions, and many satellite sessions featuring highly diverse and cutting-edge research. Many of the studies that will be presented have been conducted by or funded by federal partners, including NIH, CDC, PEPFAR, DoD, and others.

As is the custom in Australia, HIV.gov acknowledges the Jagera and the Turrbal people as the Traditional Custodians of Meanjin (Brisbane), the land on which IAS 2023 is taking place. We pay our respects to Jagera and Turrbal elders past, present, and emerging.

Follow all of our conversations from IAS 2023 this week on HIV.gov’s Facebook, Instagram, and Twitter, and on the LinkedIn account of the HHS Office of Infectious Disease and HIV/AIDS Policy.