Cutting out the noise: How horseshoe bats adapt their echolocation behavior in colonies

New research shows that when wild Greater Japanese Horseshoe bats are mixed with captive colonies, they gradually converge their echolocation call frequency to avoid interference.

Doshisha University

Facebook

XLinkedInWeChat
WhatsAppEmail

 

image: 

New research reveals that mixed wild- and captive-populations of the greater Japanese horseshoe bat (Rhinolophus nippon) display frequency convergence behaviors in a major echolocation frequency, thereby reducing acoustic interference from members of the same colony and improving species sensing.

view more 

Credit: Photo by Soshi Yoshida, used with permission

Imagine searching for a gemstone in a dark cave; you use a flashlight, looking for a rainbow-colored glint in the darkness. Now, imagine ten other people in the cave with you, using different colored flashlights at the same time. Suddenly, you can no longer tell which light is coming from your gemstone, which light is from another flashlight, or which light is coming from a reflection of another unknown object. That is what echolocation with multiple, overlapping frequencies would be like. But now, imagine if every person in the cave was using a flashlight in the same color. The glint from the gemstone would be much easier to see. A new study reveals that greater Japanese horseshoe bats use a similar strategy; they align their echolocation call frequencies within a colony to avoid interference and better ‘see’ their surroundings.

Bats are an ecologically important species, responsible for pest control, pollination, and seed dispersal. They use echolocation to ‘see,’ emitting ultrasonic sound waves that bounce back off objects and give them an idea of what, where, and how fast these objects are. Understanding bat echolocation is essential for revealing how animals perceive and navigate their environment. Moreover, the sophisticated sensing strategies of bats have inspired advances in bio-inspired sensing technologies and autonomous robotic systems. For example, sonar technologies are constantly being improved based on observations from echolocating species like bats.

Most bats use frequency-modulated (FM) acoustic pulses, i.e., they vary the frequency of single sound waves in their calls. However, some bat species, such as the greater Japanese horseshoe bat (Rhinolophus nippon) use unique pulses that include both FM components and constant-frequency (CF) components. The bats detect and identify prey through ‘glints’, periodic modulations in the amplitude and frequency of the reflected CF component of the echolocation call. Additionally, these bats have a special anatomic feature called the acoustic fovea that shows exceptional sensitivity to a narrow frequency band that is centered on the second harmonic CF component (CF2) of the echolocation pulse. CF-FM bats adjust the CF component of their echolocation calls to ensure that the CF2 component falls within the acoustic fovea to compensate for a phenomenon known as ‘Doppler shift,’ where the frequency recorded by a moving observer or emitted by an object in motion changes based on their speed and direction of motion.

Now, what happens when you mix a group of bats with overlapping CF2 frequency bands? This was the driving question behind a new study, published in Journal of Comparative Physiology A. The study, authored by Haruhito Matsumoto, Soshi Yoshida, and Shizuko Hiryu of Doshisha University, describes how, when wild greater Japanese horseshoe bats are mixed with captive colonies, they modify their CF calls in an unusual way. “Unlike some other echolocating bats that separate their call frequencies to avoid interference, these horseshoe bats appear to converge on a shared frequency. Building on our previous study showing that they use a ‘silent spectral window’ to detect Doppler-shifted echoes from fluttering prey, we propose that this convergence allows colony members to maintain and share that window,” explains Dr. Soshi Yoshida.

Elucidated in a previous work, ‘silent spectral window’ refers to a clutter-free band of frequencies above a given threshold that allows for more effective sensing of prey. Here, the horseshoe bats adjust their echolocation frequencies so that most background acoustic interference remains below the threshold. Since Doppler-shifted acoustic glints from fluttering prey occur within this clutter-free frequency band, the silent spectral window enables reliable detection of these prey signals.

For their study, the researchers captured wild horseshoe bats across 15 different time points and measured their CF2 frequencies. The bats were then introduced into a captive colony of the same species of bats, and their CF2 frequencies were measured again after a month. From 2008 to 2024, data was collected from wild and captive bats across 15 capture events to obtain information on convergence. Significantly, the researchers observed an asymmetric pattern to the convergence; lower-frequency individuals (typically, wild-caught bats) strongly shifted their frequencies upwards during convergence. When there were no initial differences in frequency between the wild group and the captive group, no such convergence occurred. “This observation was only possible because past and present laboratory members carefully recorded the calls of individual bats over many years. It highlights the scientific value of long-term data accumulated through sustained effort,” says Dr. Yoshida.

The upward shift displayed by lower-frequency individuals supports the idea that convergence is a strategy employed by horseshoe bats to share a silent spectral window above the CF2 frequency. Essentially, when lower-frequency bats received their echolocation bounce backs from prey (i.e., glints), they were in the same range as the higher-frequency calls of other bats in the colony. By shifting their frequencies higher, the lower-frequency bats could avoid that conflict. At the same time, the higher-frequency bats already enjoyed a clear window for their glints and so had less of a driving force to adjust their calls.

Overlap in echolocation frequency is a major challenge to sensing in same-species colonies of bats, but research on acoustic interference in mixed populations of same-species bats is scarce. This study helps fill that gap and provides new insight into how bats interact at an individual level and achieve high-sensory performance in echolocation.

---

Profile

About Soshi Yoshida from Doshisha University, Japan
Dr. Soshi Yoshida received his Doctor of Engineering degree from the Graduate School of Life and Medical Sciences at Doshisha University, Japan, in March 2026 and is currently affiliated with the American Museum of Natural History as a JSPS Overseas Research Fellow. His research focuses on bat echolocation, bioacoustics, sensory ecology, and neuroethology, especially how bats use Doppler-shifted sounds for navigation and prey detection. In recognition of his contributions, he received the prestigious JSPS Overseas Research Fellowship, awarded by the Japan Society for the Promotion of Science.

About Shizuko Hiryu from Doshisha University
Shizuko Hiryu is a Professor in the Department of Biomedical Engineering, Faculty of Life and Medical Sciences at Doshisha University, and Director of the Acoustic Navigation Research Center.
Her research interests include ultrasonic engineering, bat bioacoustics, and sensing technologies. She has published extensively in these fields, with a particular focus on bat echolocation and acoustic simulation.
In recognition of her pioneering research on bat echolocation and bioacoustics, she has received numerous awards, including the Young Scientists' Prize from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) and the JSPS Prize from the Japan Society for the Promotion of Science (JSPS).

---

Journal

Journal of Comparative Physiology A

DOI

10.1007/s00359-026-01821-5 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Greater Japanese horseshoe bats (Rhinolophus nippon) gradually converge their echolocation call frequency to colony members

 

Birds’ flying ‘V’ formation saves energy with flatter flaps, new research shows

Brown University

Facebook

XLinkedInWeChatBlueskyMessageWhatsAppEmail

PROVIDENCE, R.I. [Brown University] — Scientists have known for years that birds like geese and ibises get an aerodynamic advantage from flying in a “V” formation. Now, researchers from Brown University have provided new insights into the nature of that advantage. 

In a study published in Proceedings of the National Academy of Sciences, Brown researchers Olivia Pomerenk and Kenny Breuer developed an aerodynamic model that simulates the forces at play when one flapping bird — specifically a northern bald ibis — follows another behind and off to the side, the classic V formation sweet spot. The model showed that birds in that position experience an 11% reduction in the mechanical power needed for flight. Those savings are driven largely by a reduction in the vertical distance of their wing flaps. 

“The big change we see in this position is in the amplitude of flapping,” said Pomerenk, a postdoctoral researcher in Brown’s School of Engineering. “At least for this specific bird species, we're looking at an amplitude that is something like 70% of what it would be if the bird were flying alone. That’s a pretty dramatic change.”

Breuer, a professor of engineering and of ecology, evolution and organismal biology at Brown, has long been interested in animal flight. His lab at Brown, which is equipped with a custom-made wind tunnel festooned with high-speed cameras, has made numerous discoveries about the flight dynamics of both bats and birds. Experiments done with starlings in the wind tunnel a few years ago helped to confirm that the V formation does help trailing birds save energy — reducing the energetic cost of flight by 25% in wind tunnel flights. 

The energetic benefit is likely linked in some way to wingtip vortices, tiny horizontal tornadoes that spin off the tips of each wing. The airflow from those vortices creates an area of aerodynamic “downwash” directly behind the bird, and an area of “upwash” off to the side. That upwash zone, Breuer and Pomerenk say, is the likely source of the aerodynamic advantage, but exactly how it translates into less work for a bird was a mystery. That’s what this new model attempts to reveal.  

A major question is whether the upwash generates extra lift for the birds, or extra thrust. 

“If I'm a flying bird, I have two problems to solve,” Pomerenk said. “I have to generate lift so I can counter gravity, and I have to generate thrust so I can fly forward. Those two problems both require energy to solve, but they might be affected differently by flying in another bird’s wake.” 

Prior research has either oversimplified the problem or overcomplicated it, Pomerenk says. The simplest models treat birds much like fixed-wing aircraft. That eliminates the dynamics introduced by flapping, which are of obvious importance to bird flight. But the more complicated models and real-world experiments are problematic too, often burying important dynamics in a jumble of complexity.

The researchers’ new model breaks the problem down to the essentials. Using prior experimental research on northern bald ibises, Pomerenk and Breuer carefully modeled the wake produced by a single flapping bird, then added a second bird flying in that wake. Because the lead bird is flapping its wings, its wake undulates vertically with each flap. To capture the effects of that undulation on the trailing bird, the model breaks the action down into a series of snapshots over time. 

“If I press freeze on the world, we’re left with a wake that’s in a certain position and a follower's wings in a certain position,” Pomerenk explained. “There are a bunch of fluid dynamics theorems that you can apply in sequence to arrive at the forces on the trailing bird at that moment in time.”

By adding those snapshots up, the model zeros in on the effects of the undulating wake. The work showed that a lead bird’s wake reduces the need for a trailing bird to generate thrust. That enables the bird to reduce the amplitude of its flaps, which in turn saves energy. All of the model findings are consistent with experimental observations but add a much-needed explanation for how exactly a leading bird’s wake translates into an easier ride for a trailing bird. 

That explanation could be applied beyond avian flight.

“There are also implications for engineered systems,” Breuer said. “All of this can also be applied to understanding how to best operate swarms of drones used in agriculture or firefighting, for example.”

Pomerenk says she’s hopeful that the model of two-bird interaction can eventually be incorporated into a larger model of avian flight that includes social and behavioral dynamics. In that way, the work could prove an important step in understanding the formations and murmurations that have long fascinated birdwatchers and scientists alike.

The research was supported by the U.S. Office of Naval Research (N00014-21-1-2816) and the U.S. National Science Foundation (IOS-1930924).

---

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2606668123 

Article Title

A minimal wake–vortex model explains formation flight of flapping birds

Article Publication Date

21-Jul-2026

 

COVID-19 vaccine boosters may help protect against future animal coronaviruses

First exposure to SARS-CoV-2 ‘locks in’ our immune response

University of Cambridge

Facebook

XLinkedIn
MessageWhatsAppEmail

COVID-19 vaccine boosters not only protect against SARS‑CoV‑2 – the virus behind the most recent pandemic – but may also help protect against some future coronaviruses that risk spreading from animals to humans, Cambridge researchers have shown.

In a related study, the team has shown that an individual’s first exposure to SARS‑CoV‑2 ‘locks in’ their immune response, impeding their ability to respond to future variants, even when vaccinated.

When an individual is infected with a virus, the immune system produces antibodies that will recognise the virus if it re-enters the body and prevent infection taking hold again. Vaccination works on the same principle.

A team led by scientists in the Gupta and Rihn laboratories at the Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), University of Cambridge, asked whether the vaccines currently given against COVID-19 might also protect us against future coronaviruses that risk ‘spilling over’ from animals to humans.

In findings published today in the journal npj Vaccines, the team studied blood samples from older UK adults (average age around 69) who had received four COVID‑19 vaccine doses, including a recent bivalent booster that included both the original Wuhan strain and the Omicron variant.

They tested how well antibodies in these blood samples could neutralise different Omicron variants of SARS‑CoV‑2. They also tested the antibodies to see if they could neutralise the SARS‑CoV‑1 virus – responsible for the 2003 SARS outbreak – and a range of closely-related coronaviruses (known as ‘sarbecoviruses’) found in bats and pangolins, some of which are considered potential threats for future outbreaks.

As expected, antibodies worked less well against newer Omicron variants than against the original Wuhan strain, showing how the virus has evolved to escape the immune response. The antibodies were poor at neutralising SARS‑CoV‑1, which is genetically more distant.

Surprisingly, the antibodies were much better at neutralising two sarbecoviruses closely related to SARS‑CoV‑2 – one from bats and one from pangolins – than they were at neutralising the original Wuhan strain itself, even though these two viruses have never infected humans. Several of the bat and pangolin viruses tested have the ability to enter human cells and are genetically close enough to SARS‑CoV‑2 to raise concern about future spillovers.

Grace West from CITIID, the study’s joint first author, said: “We’d expect the COVID vaccine to offer protection against today’s variants, but we were surprised to find that it also provides protection against some animal coronaviruses with future pandemic potential.”

Rebecca Morse, also a joint first author from CITIID, said: “We may already have a head start when it comes to protecting against certain future outbreaks. Boosters could reduce both severity and spread if spillover were to occur, buying us vital time while we develop a more targeted vaccine. This will be particularly important for older and vulnerable populations, who are usually hardest hit in new pandemics.”

The researchers say their findings could inform next‑generation vaccine design. Vaccines that target parts of the coronavirus spike protein common to multiple viruses could protect against related viruses. The spike protein is a key element of the virus that the immune system recognises.

The research was funded by Wellcome and the Medical Research Council, with additional support from the Hong Kong Jockey Club, National Institute for Health and Care Research (NIHR) Cambridge Biomedical Research Centre and Addenbrooke’s Charitable Trust.

Why ‘first impressions’ matter when it comes to COVID-19 immunity

In a second study, Professor Ravindra Gupta and colleagues showed how your first encounter with COVID-19 – either through infection or vaccination – leaves a lasting immune ‘fingerprint’ that shapes how you respond to new variants for years, with important implications for vaccine design and pandemic preparedness.

Early on in the pandemic, relatively low reported case numbers in many African countries led to the perception that these countries had experienced limited exposure to SARS-CoV-2. But when the team analysed blood samples from unvaccinated adults in Nigeria in early 2023, they found that this was not the case – most individuals had already been exposed to the virus, often more than once, despite many never having been diagnosed or reporting illness.

This presented the team with a rare opportunity to understand how immunity builds up when infection comes first, rather than vaccination. Their findings are published in the journal iScience.

Using two independent cohorts sampled in 2023 while Omicron was circulating, the team found that immune responses were still dominated by earlier strains of the virus, even after subsequent infection with Omicron. This reflects a phenomenon known as ‘immune imprinting’, where the first exposure to the virus – whether through infection or vaccination – largely determines how the immune system will respond in future. Even after vaccination against or infection by subsequent variants, the immune system still responds as if the virus had not changed since that first exposure, increasing the chances that the virus will ‘escape’ the immune response.

First author Dr Adam Abdullahi from CITIID, Cambridge, and the Institute of Human Virology, Abuja, Nigeria, said: “The immune system doesn’t reset with each new variant. Instead, it builds on its first encounter, and that memory continues to influence how it responds to new variants. It’s like how, when we have a negative encounter with someone the first time we meet, this first impression can be hard to shake and informs how we deal with them each time we meet.”

To investigate this further, the team removed antibodies targeting earlier strains from the blood samples. With these antibodies removed, the blood was much less able to neutralise either the earlier variants of COVID-19 or Omicron, confirming that responses to newer variants were largely built on pre-existing immune memory.

Although vaccination increased overall antibody levels, it appeared to amplify existing immune memory, boosting responses shaped by earlier infections rather than generating strong new responses to variants such as Omicron. Even after further exposure to Omicron, antibody responses rarely became stronger against this variant than against the original virus.

In other words, immune responses, established during early infection, can persist over time, constraining the body’s ability to mount new responses to new variants, even after vaccination or re-exposure.

This suggests that in populations with high levels of prior infection, vaccine performance is partly determined by the sequence of exposures individuals have experienced, including whether infection occurred before vaccination, and which variants were encountered first. The findings may help explain why new variants keep spreading, even in populations with high prior exposure

Ravindra Gupta, The Hong Kong Jockey Club Professor of Global Health at CITIID, University of Cambridge, said: “Vaccines are still extremely important as they help reduce the severity of infection, so it’s important to get your boosters if you are vulnerable. But our findings help explain why we see different patterns of immunity across the world. The pandemic did not unfold uniformly, and our vaccination strategies need to reflect that reality.

“Early infection leaves a lasting imprint on the immune system, and in this context, we need to look at designing vaccines that work across different immune histories to help prepare for future pandemics.”

Professor Alash’le Abimiku from the Institute of Human Virology, Nigeria, joint lead author, said: “Understanding how populations were exposed to the virus is essential for designing effective vaccination strategies, particularly in settings where infection occurred before vaccine rollout. Future vaccines may need to be designed so they don’t just ‘replay’ the immune system’s past experiences, but instead actively train it to recognise and respond well to new variants.”

Imprinting may also explain why the COVID vaccine offers greater protection against some sarbecoviruses than it does later variants of SARS-CoV-2, such as Omicron, as reported in the npj Vaccines study.

The original vaccine, like an infection during early COVID-19 waves, caused imprinting of our antibodies against the Wuhan strain, and as the virus mutated over time, the immune system would be increasingly less likely to recognise it. However, some of the bat and pangolin coronaviruses have spike proteins that are more similar to that of the Wuhan strain of SARS-CoV-2 than the spike proteins of Omicron and subsequent variants.

Professor Gupta, who leads The HKJC Global Health Institute, added: “This work was only possible because of close collaboration between Nigerian institutions and international partners, each bringing its own expertise. These partnerships are critical to ensuring that globally relevant evidence is generated from, and directly benefits, populations most affected by emerging infectious diseases.”

The research was funded by The Hong Kong Jockey Club Global Health Institute, Harding Distinguished Postgraduate Scholars Program and European Research Council, with additional support from the NIHR Cambridge Biomedical Research Centre.

Reference

1. West, GE, & Morse, RB, et al. COVID-19 vaccination induces cross-neutralisation of sarbecoviruses related to SARS-CoV-2. npj Vaccines; 1 July 2026; DOI: 10.1038/s41541-026-01469-x
2. Abdullahi, A,  Morse, RB, & Cheng, TKM, et al. SARS-CoV-2 Omicron infection reveals imprinted 1 antibody responses in the absence of vaccination. iScience; 28 April 2026; DOI: 10.1016/j.isci.2026.115910

---

Journal

npj Vaccines

DOI

10.1038/s41541-026-01469-x 

Method of Research

Observational study

Subject of Research

Cells

Article Title

COVID-19 vaccination induces cross-neutralisation of sarbecoviruses related to SARS-CoV-2

Article Publication Date

1-Jul-2026

 

11-year-old boy dies from rabies in Canada after waking up to a bat on his face

Copyright AP photo

By Nathan Rennolds

Published on 02/07/2026 - EURONEWS

Rabies is a rare but deadly infection usually spread by a bite or scratch from an infected animal. It is almost always fatal after the onset of symptoms, although vaccination and early treatment can help to prevent it.

An 11-year-old boy died from rabies in Canada after he woke up to find a bat "on his nose and mouth," according to a report in the Canadian Medical Association Journal.

The boy died in hospital in Ontario after developing severe symptoms including bulbar palsy, a neurological condition affecting the nerves controlling muscles used for speaking, swallowing, and breathing.

His family said that around 19 days before the onset of initial symptoms, he had been staying in a cottage in northern Ontario, where he had been awoken by a bat on his face.

The child swatted the bat away and the father caught it and released it. The boy is said to have had no visible lesions from the incident and "his parents did not consider that the bat had behaved erratically". They therefore decided not to seek medical advice.

The boy later began experiencing facial numbness and swelling and was taken to a local urgent care clinic, where he was prescribed antiviral medication for suspected Bell's palsy - temporary weakness or lack of movement usually affecting one side of the face.

He then had consecutive visits to hospital after he began vomiting and developed pain while swallowing, receiving an initial diagnosis of severe herpes gingivostomatitis, an oral infection that can cause painful sores.

But the child's condition began to deteriorate. He developed a fever of 39.1°C, as well as difficulty swallowing, confusion, hallucinations, hypersalivation and neurological conditions. He was intubated and taken to a paediatric intensive care unit while medical staff consulted with the infectious diseases service.

"When we saw the patient in the PICU, we strongly suspected rabies, given the bat exposure and typical neurologic features," doctors said. Tests confirmed rabies on the boy's fourth day in hospital.

"The patient’s hospital course was complicated by autonomic dysfunction, ventilator-associated pneumonia, and progressive neurologic decline," per the journal entry. "By day 5 of admission, his brain stem reflexes were absent. Life-sustaining therapies were withdrawn on day 17 of admission, and he died peacefully with his family at his bedside".

Rabies is a rare but deadly infection usually spread by a bite or scratch from an infected animal.

It is almost always fatal after the onset of symptoms, although vaccination and early treatment can help to prevent it.

According to the US's Centers for Disease Control and Prevention, there are a number of "unusual" behaviours that can indicate rabies in bats. It says people should watch out for bats that are active during the day, that are found in unusual places such as inside a home or on the ground, that are unable to fly or are easy to approach, or that have "made contact with you".

Fauci Summoned To Testify Before Powerful Senate Committee In July

SENATOR RAND PAUL PERSECUTES THE HERO OF COVID

Dr. Anthony Fauci. Official White House photo by Tia Dufour/Wikimedia Commons


June 24, 2026
 The Center Square
By Thérèse Boudreaux

(The Center Square) – The Republican head of a powerful U.S. Senate committee has subpoenaed Dr. Anthony Fauci, demanding the former chief medical advisor testify before lawmakers about his response to the COVID-19 pandemic.

“For six months, I have been negotiating with Anthony Fauci’s lawyers over a date to testify before my Homeland Security Committee. He finally agreed to appear this month. Then he backed out. So I subpoenaed him,” Senate Homeland Security and Government Affairs Committee Chairman Rand Paul, R-Ky., posted on social media Tuesday. “He will testify in July.”

In a separate post, Paul outlined some of the questions he intends to ask Fauci, who headed the nation’s pandemic response.

“Did Dr. Fauci fund gain-of-function research while telling Congress he didn’t? Why were records destroyed? And why did he need a presidential pardon? The American people deserve answers, and I am going to make sure they get them during our hearing next month,” Paul said.

Fauci, who received a preemptive pardon from former President Joe Biden, has faced criticism over his handling of the pandemic response.

Paul and other Republicans have accused Fauci of covering up the true origins of the virus after a National Institutes of Health official revealed in 2024 that U.S. taxpayer dollars had indeed funded what many would term “gain of function” research at the Wuhan Institute of Virology in the area where the virus was first discovered.

The admission contradicted Fauci’s assertion to Congress in 2021, under oath, that the “NIH has not ever and does not now fund gain-of-function research in the Wuhan Institute of Virology,” a statement Republicans considered intentionally misleading.

Paul’s subpoena Monday came just days after former Director of National Intelligence Tulsi Gabbard declassified hundreds of documents, which she claims “expose Fauci’s direct role in influencing and manipulating IC assessments on COVID-19.”

Among other records, Gabbard declassified the U.S. taxpayer-funded research on coronaviruses, which analyzed the risks of coronavirus spreading from bats to humans, that NIH had admitted to funding. The controversy-ridden nonprofit EcoHealth Alliance conducted those studies, some of which dated back to 2014.

During the pandemic, Fauci repeatedly discouraged the idea that the virus originated from a lab.

But the other documents Gabbard declassified, which largely consist of email exchanges between federal health and IC officials, fall short of proving that he “worked with politicized career leadership in the Intelligence Community (IC) to suppress the truth about his actions” and the lab leak theory.

The declassified information shows Fauci was included in the communications between federal health agencies and the Intelligence Community, both involved with pandemic research and response and both attempting to clear up conflicting information.

Per the emails, Fauci often advised IC officials – who specifically asked health officials for advice and clarification on how to interpret virus-related research and other theories – and recommended they consult certain health experts for additional information. He also provided his opinion that the virus was zoonotic in origin when asked.

Most health officials in the emails, whose names were largely redacted, emphasized caution related to assertions that the virus was created in a lab.

One email written by an IC official read “Hi team – Is anyone looking at the open source report that a Chinese virologist claims to have proof that COVID-19 was made in a Wuhan lab? We’re getting questions from our leadership and I figured those with more technical expertise probably have already evaluated this report.”


A recipient – presumably from the NIH, but both the name and office of the respondent are redacted – informed the IC official that the study in question had numerous errors and was published by a pair of nonprofit groups, which had never before released any medical research, linked to political strategist Steve Bannon.

Some of the health officials acknowledged that coronaviruses were likely studied in the WIV lab. They also confirmed that a lab analysis found that “all of the necessary conditions for an accidental release of a laboratory-modified coronavirus — specifically a coronavirus adapted to recognize human cell receptors” were present at the WIV in 2019.

However, they pointed out to IC officials that the authors of the report determined the findings “place equal weight on the hypothesis” of an accidental lab leak versus the virus emerging naturally in Wuhan.

“I’ve been tracking this pretty closely in the literature, and would advise to set a very high threshold for any GOF [gain of function] interpretation as an origin of SAR COV-2,” a health official whose name is redacted said. “Not saying it is impossible, but I think Occam’s razor is the best guidance here. […] To be honest – I cannot imagine the Chinese NOT doing this type of research, but an escaped P3+/P4 LAI would be extraordinary.”

While the origins of the virus still remain under debate, the White House has officially endorsed the lab leak theory.

 

Looking at the data since 1976: low risk of global spread of Ebola disease

Most effective strategy to reduce exportation of cases: local, community-based case management, infection prevention and control at the outbreak source

European Centre for Disease Prevention and Control (ECDC)

Facebook

XLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

Since 1976, the authors idnetified 28 confirmed Ebola disease cases outside Africa: 25 primary imported cases and three secondary cases infected by another patient in the United States (US) or Europe. 

view more 

Credit: Eurosurveillance

In previous Ebola disease outbreaks in Africa as well as the current outbreak of Ebola disease caused by Bundibugyo virus in the Democratic Republic of the Congo, immediate neighbouring countries are most affected when it comes to cross-border spread. As decision-makers outside Africa may be considering border and travel policies to interrupt pathways for international transmission, van Zandvoort et al. identified and analysed all known Ebola disease cases outside Africa to assess the risk of undetected Orthoebolavirus transmission outside Africa and to put it into context with possible border and travel policies. [1]

The authors searched for all laboratory-confirmed Ebola disease cases that presented outside of Africa since 1976 to date across scientific articles, public health bulletins and news reports including cases due to Bundibugyo, Ebola and Sudan virus outside Africa with exposure in Africa and subsequent travel outside the continent, as well as cases with exposure outside Africa.

Two types of exported cases: medical evacuation and latent
In total, the search yielded 28 identified confirmed Ebola disease cases outside Africa during the period 1976 to May 2026 with 25 primary imported cases and three secondary cases infected by another patient in the United States (US) or Europe.

The analysis distinguishes between two types of primary exported cases. On the one hand the analysis included people who were medically evacuated, i.e. securely transported by air ambulance for treatment outside Africa following a confirmed infection. On the other hand, latent cases were defined as people who developed symptoms during or after their return from the outbreak region on a commercial flight. While the first group represents a known risk with the possibility to mitigate transmission risk with strict measures, the second group requires diagnosis and isolation.

Most of the identified cases (27) occurred during the 2014–16 Ebola virus epidemic in Western Africa and one during the ongoing 2026 Bundibugyo virus outbreak. The authors detected four latent cases, all of which were exported during the 2014–16 Ebola disease epidemic. These four cases were among 300,000 travellers who underwent screening at the time. However, all four were asymptomatic (and hence undetectable) at the point of both exit screening and entry screening. Three were returning healthcare workers responding to the epidemic and one had helped a pregnant person obtaining medical assistance.
 

Low overall risk of exportation
Based on these data, according to van Zandvoort et al., the crude overall risk since the year 2000 was 0.17 Ebola disease cases outside Africa per 1,000 reported cases in Africa (excluding medically evacuated cases). The authors conclude “our results suggest overall that the risk of case exportations is low and could be substantially mitigated by infection prevention measures at the outbreak source and among outbreak response workers, in concert with enhanced travel screening and monitoring for returning response workers, as recommended in WHO border and travel guidance for the current outbreak.

The authors thus have the view that “as exit screening in an outbreak-affected country aims to reduce case importations in other countries, it is a shared international responsibility. This may be best supported by strengthening local capacity for such screening.”

 

----Ends----

References/notes to editors:
[1] van Zandvoort Kevin, Procter Simon R, Azam James, Sherratt Katharine, Davies Nicholas G. The risk of global Ebola virus spread is low: epidemiology of Ebola disease cases outside Africa, 1976 to May 2026. Euro Surveill. 2026;31(24):pii=2600508. Available from: https://doi.org/10.2807/1560-7917.ES.2026.31.24.2600508

[2] Ebola disease is caused by viruses belonging to the genus Orthoebolavirus, Filoviridae family. There are four orthoebolaviruses that can cause disease in humans. See more: https://www.ecdc.europa.eu/en/ebola-disease

[3] Ebola disease outbreak in the Democratic Republic of the Congo and Uganda, ECDC outbreak page. Available from: https://www.ecdc.europa.eu/en/ebola-outbreak-democratic-republic-congo-and-uganda

---

Journal

Eurosurveillance

DOI

10.2807/1560-7917.ES.2026.31.24.2600508 

Method of Research

Data/statistical analysis

Article Title

The risk of global Ebola virus spread is low: epidemiology of Ebola disease cases outside Africa, 1976 to May 2026

Article Publication Date

18-Jun-2026

Hantavirus and Ebola virus disease: 10 things to know

Canadian Medical Association Journal

WeChat
WhatsAppEmail

Two deadly infectious diseases, Ebola  https://www.cmaj.ca/lookup/doi/10.1503/cmaj.260834 and hantavirus https://www.cmaj.ca/lookup/doi/10.1503/cmaj.260789, have made headlines in recent weeks as they pose serious threats to public health. They both require rigorous infection and prevention control (IPAC) practices and often present with similar early symptoms.

Two succinct articles in CMAJ (Canadian Medical Association Journal) provide information about each disease for clinicians.

Hantavirus:

1. A nationally notifiable disease in Canada — In Canada, 4 to 5 cases are confirmed every year and must be reported. These are usually acquired from rodents in agricultural settings in Manitoba, Saskatchewan, Alberta, and British Columbia. The Andes strain is unique as it can be transmitted from person to person.
2. Causes 2 clinical symptoms — Strains in the Americas, which include the Andes virus featured recently in the news, cause hantavirus cardiopulmonary syndrome. The European and Asian strains cause hemorrhagic fever and kidney dysfunction. Both forms take about 2 to 4 weeks to incubate, and symptoms include fever, headache, muscle aches, and abdominal pain.
3. Serology and polymerase chain reaction (PCR) tests are diagnostic — The National Microbiology Laboratory in Winnipeg performs these tests.
4. Supportive treatment — As there is no specific antiviral treatment or vaccine for hantavirus, treatment is supportive to help alleviate symptoms.
5. IPAC protocols are essential — Patients with suspected Andes strain infection must be isolated with airborne, droplet, and contact precautions, with infectious diseases experts involved and public health notified.

Ebola virus disease:

1. Sporadic outbreaks have occurred in Central and West Africa since 1976 — There are 3 main viruses that can infect humans, and evidence suggests they come from fruit bats. Ebola virus is spread via person-to-person contact through bodily fluids like vomit, sperm, diarrhea, and blood, as well as by touching infected surfaces or objects. The current outbreak in the Democratic Republic of Congo is Bundibugyo ebolavirus, with a fatality rate of 30% to 50%.
2. Fewer than 50% of patients have hemorrhagic symptoms — Symptoms include fever of 38°C or higher, fatigue, muscle pain, and gastrointestinal distress. Incubation is 2 to 21 days, and diagnosis is made with PCR testing.
3. People with potential symptoms and exposure risk should be tested — People who have travelled to countries with Ebola virus disease or who have been in close contact with infected people or bats, primates, or game from the affected areas should be tested.
4. Stringent IPAC must be used for suspected cases — Health Canada has a detailed process for screening, assessment, and IPAC precautions, which must include a fit-tested N95 respirator, face shield, gloves, and fluid-impermeable gear for full protection.
5. Important advances in prevention and management of the disease have been made — Vaccines to prevent Zaire ebolavirus are very effective, and 2 antivirals can reduce mortality from 50% to 35%. However, there are no current vaccines or medications to prevent or treat Bundibugyo ebolavirus, for which supportive care is the main approach.

---

Journal

Canadian Medical Association Journal

DOI

10.1503/cmaj.260834 

Method of Research

Literature review

Subject of Research

People

Article Title

Hantavirus”and “Ebola virus disease

Article Publication Date

22-Jun-2026