Low-dose CT chest scans could help detect pneumonia in at-risk patients while exposing them to only small amounts of radiation, a new study has found. The research, published in Radiology: Cardiothoracic Imaging, shows that ultra-low-dose scans can effectively detect pneumonia in patients with compromised immune systems, enabling doctors to treat the infection before it becomes life-threatening. According to the researchers, these scans expose patients to just 2% of the radiation dose used in a standard CT scan.

"This study paves the way for safer, AI-driven imaging that reduces radiation exposure while preserving diagnostic accuracy,” lead researcher Dr Maximiliano Klug, a radiologist with the Sheba Medical Center in Ramat Gan, Israel, said in a news release. He added that CT scans are the gold standard for detecting pneumonia but there are concerns regarding the risk posed by repeated exposure to radiation. There is a solution- ultra-low-dose CT scan. However, the problem is that these scans can be grainy and hard to read, researchers said.

Study Gives Solution To This

To overcome that, Klug's team developed an AI program that could help "de-noise" low-dose scans, making them sharper and easier to read. Between September 2020 and December 2022, 54 patients with compromised immune systems who had fevers underwent a pair of chest CT scans -- a normal dose scan and an ultra-low-dose scan. The AI program cleaned up the low-dose scan, and then both sets of images were given to a pair of radiologists for assessment. Radiologists had 100% accuracy in detecting pneumonia and other lung problems with the AI-cleaned low-dose scans, but 91% to 98% accuracy in examining the scans that hadn’t been improved through AI, results show.

"This pilot study identified infection with a fraction of the radiation dose," Klug said. "This approach could drive larger studies and ultimately reshape clinical guidelines, making denoised ultra-low dose CT the new standard for young immunocompromised patients.

How Can You Detect Pneumonia?

Pneumonia is a lung infection that causes the air sacs in the lungs to fill with fluid or pus and can be caused by bacteria, viruses, or fungi. The symptoms can range from milk to severe, which includes:

Coughing with or without cough

Fever

Chills

Trouble breathing

Chest pain, especially when breathing deeply or coughing

Sweating or chills

Rapid heart rate

Loss of appetite

Bluish skin, lips, and nails

Confusion.

How to detect Pneumonia in coughing newborns and toddlers?

Pneumonia can severely affect newborns and young children as their lungs are comparatively more sensitive. As per Dr Goyal, young children can cough for various reasons including seasonal infections and tonsillitis, which is very common in this age group. But if they look visibly irritable and have poor sleep patterns, then parents must reach out to an expert. "I am not saying that parents must visit a hospital but any local paediatrician would be able to detect pneumonia in your kid.

The US Centers for Disease Control and Prevention (CDC) has reported another norovirus outbreak aboard a Cruise ship that has sickened nearly 125 people.

So far this year, the CDC has reported seven outbreaks on cruise ships under its jurisdiction, five of which were caused by norovirus.

Nearly 125 People Fall Ill

The outbreak occurred aboard the Ruby Princess during a 20-day voyage along the west coast of North America.

According to the CDC, 102 passengers and 23 crew members reported gastrointestinal illness during the voyage.

The outbreak was first reported to the CDC's Vessel Sanitation Program on June 28.

The Ruby Princess was carrying more than 3,000 passengers and 1,144 crew members during the outbreak.

According to the CDC, Princess Cruises and the ship's crew implemented increased cleaning and disinfection procedures under the company's outbreak prevention and response plan.

Crew members also collected stool specimens from affected individuals for testing, isolated ill passengers and crew members, and consulted with the CDC's Vessel Sanitation Program.

What Is Norovirus?

Norovirus is a highly contagious virus that causes gastroenteritis, leading to inflammation of the stomach and intestines.

Speaking to HealthandMe, epidemiologist Dr. Amitav Banerjee, professor at DY Patil Vidyapeeth, Pune, described norovirus as “notorious because it spreads very fast.”

“It can spread through fomites like handles and knobs, and even a very low infectious dose—around 18 viral particles—can cause infection. So it spreads very fast,” he said.

He added that while many common disinfectants are ineffective against it, norovirus can be inactivated using bleach and chlorine-based cleaning agents.

Is The Norovirus Outbreak Of Concern?

Although outbreaks can look alarming, Dr. Banerjee emphasized that norovirus infections are generally self-limiting.

“In the ship, it can be managed with oral rehydration, and in severe cases, IV fluids can help prevent complications and mortality,” he said.

Dr. Banerjee also clarified that, unlike diseases with pandemic potential, norovirus outbreaks—while explosive in nature—do not typically pose a long-term global threat.

"Norovirus is a stomach infection contracted through the consumption of contaminated food or water or through contact with an infected individual. The infection is highly contagious, but not life-threatening, and is manageable with proper care and hydration," Dr Suresh Kumar D, Senior Specialist - Infectious Diseases, Apollo Speciality Hospitals, Vanagaram, Chennai, told HealthandMe.

Who Is Most at Risk? What Are The Key Symptoms

Dr. Banerjee noted that extreme age groups, especially very young infants and the elderly, are at higher risk due to dehydration from diarrheal illness. However, deaths remain rare when proper care is provided.

Norovirus illnesses usually last between two and three days. Symptoms usually begin suddenly within 12 to 48 hours of exposure and may include:

• Nausea
• Vomiting
• Watery diarrhea
• Stomach cramps
• Low-grade fever
• Headache and body aches
• Fatigue

What You Can Do To Stop Its Spread

Because of how fast viruses spread, experts highly recommend preventive actions such as:

• Wash your hands frequently with soap and warm water, especially after using the toilet or before preparing food.
• Avoid visiting hospitals or care homes if experiencing symptoms.
• Stay home for at least 48 hours after symptoms subside to prevent spreading the virus.

Health officials in Australia have confirmed two more suspected cases of H5 bird flu in migratory birds in Western Australia and New South Wales.

The latest detections take the total number of cases to five in Australia, which is no longer H5-free. The first two cases were reported in Western Australia. The third case of avian influenza was recorded in a giant petrel found at Knights Beach on the Fleurieu Peninsula.

H5 Detected in New South Wales

ABC News reported that samples taken from a giant petrel near Hawks Nest on the NSW Mid North Coast tested positive for the influenza strain in preliminary testing.

NSW Agricultural Minister Tara Moriarty said the bird was wild and had flown in from "other parts of the world" after being identified by a member of the public who noticed it was ill.

"We don't know yet if it is the worst strain of the virus," she said.

Samples from the bird at NSW's Bennetts Beach have been sent to the national testing laboratory in Geelong to determine the strain after being assessed by veterinarians and testing positive for H5 at an agricultural institute in Sydney's Camden.

"We expect to have the results of that at some point tomorrow," Moriarty said.

The NSW Government said it marks the first wild migratory seabird in the state to return a suspected positive result.

Also read: Australia Reports H5 Bird Flu In Second State; Can It Spread to Humans?

H5 Confirmed in Perth

Authorities in Western Australia confirmed H5 in a dead giant petrel found near Mullaloo in Perth's north. It is the first time the infection has been detected in the Perth metropolitan area.

The other WA cases were detected at Quindalup, about 250 kilometres south of Perth, and at Esperance, about 700 kilometes south-east of Perth in the Great Southern region.

Does H5 Have Pandemic Potential?

The NSW Government said that, at this stage, bird flu has not been detected in commercial poultry flocks, captive birds or any other birds in NSW. There is no evidence of mass mortality in wildlife or spread to other animals.

"This strain of avian influenza has had significant impacts overseas, causing widespread mortality in poultry, wild birds and some mammals," it said, urging the public to remain vigilant and report any sick or dead poultry, wild birds or wildlife.

Read More: Australia’s H5N1 Detection Marks End Of Last Virus-Free Continent

Professor of Immunology at Murdoch University Cassandra Berry said the detection of the H5 subtype in Australia "doesn't necessarily mean that the next pandemic has started", newsGP reported.

"Contraction of H5N1 influenza in humans usually requires close contact with sick or dying birds. So, it is cautionary to be alert and stay away from distressed birds," she said.

"Although human-to-human transmission has occurred in other countries, it is rare. Bird-to-human transmission has been associated with a high fatality (~60%). There have been nearly 1,000 cases of human H5N1 infection reported over the last three decades, since H5N1 jumped the species barrier in 1997," the expert said.

GPs Urged to Stay Alert

The Royal Australian College of General Practitioners (RACGP) has urged GPs across Australia to "remain on alert and vigilant of their patients."

The cases mark the first time this H5 subtype (H5N1 clade 2.3.4.4b) has been detected in animals in Australia.

Globally, the subtype has caused mass mortality in poultry, wild birds and sea mammals.

READ: Hantavirus Outbreak Linked To Luxury Cruise Ship Over, Says WHO

The Federal Government and the Australian Centre for Disease Control (CDC) have also updated their advice, while confirming that "the risk to human health remains low."

"Bird flu in people is rare and often mild but can cause severe disease or death. Spread from person-to-person is very rare," the CDC said.

"There have been no human cases of bird flu caused by influenza A virus subtype H5N1 clade 2.3.4.4b in Australia."

RACGP President Dr Michael Wright said it is important that GPs remain vigilant. "Now the virus has arrived, it needs to be put on GPs' radar," he told newsGP. "If you see someone potentially who has been handling these birds, particularly in WA, we need to be on alert."

Symptoms of H5 Bird Flu in Humans

According to the CDC, while some infected people have no symptoms, others may experience:

• Fever
• Cough
• Sore throat
• Runny nose
• Conjunctivitis
• Muscle aches and pains
• Headache
• Fatigue
• Gastrointestinal symptoms

Symptoms can range from mild to severe and usually begin one to 10 days after infection.

People can become infected by breathing in contaminated dust or air, or by touching an infected animal, its body fluids, or contaminated surfaces and then touching their eyes, nose or mouth.

The World Health Organization (WHO) has officially declared the hantavirus outbreak linked to the MV Hondius luxury cruise ship over after the last person being monitored completed quarantine without developing the disease.

Speaking at a media briefing on July 2, WHO Director-General Tedros Adhanom Ghebreyesus said the final person under observation tested negative after completing the recommended 42-day quarantine period for hantavirus exposure.

The individual has since returned home, and no additional infections have been detected since May 25.

"Today, the final contact of a person exposed to #hantavirus on the cruise ship MV Hondius completed their quarantine period, tested negative and returned home. No further cases have been reported since the 25th of May. Therefore, the WHO considers the hantavirus outbreak over," the WHO chief wrote on social media platform X.

The rat-borne virus outbreak infected 13 people and claimed three lives. It was caused by the Andes strain of hantavirus, which carries a risk of human-to-human transmission. There is currently no specific antiviral treatment or vaccine for the virus.

The Dutch-flagged ship departed from Ushuaia, Argentina, on April 1, visiting remote islands in the South Atlantic Ocean, including Tristan da Cunha, before heading to Tenerife in Spain's Canary Islands, where the remaining passengers were evacuated.

Also read: Can Hantavirus Spread Through Semen And Breast Milk? What Experts Say

Over 650 Contacts Traced Across 33 Countries

In an earlier post on X, Dr. Tedros said more than 650 contacts were identified and monitored by health authorities across 33 countries and territories.

"All but 54 contacts have completed their period of quarantine, and the remaining contacts are scheduled to complete their quarantine period by July 2," he told a press conference at WHO headquarters in Geneva.

"If no further cases are reported by then, WHO will consider the outbreak to be over," he added.

The WHO chief said the agency will continue efforts to better understand both the outbreak and the virus.

The UN health agency is working with partners who collected environmental samples from the ship and is coordinating a study among those exposed to better understand how the disease develops.

"We are also working on having a sample of the virus shared with the WHO BioHub in Switzerland," he said.

"This will be important for developing diagnostics, therapeutics, and vaccines for future outbreaks."

CDC Ends US Response

Meanwhile, the US Centers for Disease Control and Prevention (CDC) officially ended its hantavirus outbreak response on June 24.

The agency said none of the 18 Americans who were aboard the cruise ship became ill during the outbreak or the subsequent 42-day incubation period.

"The successful conclusion of this response demonstrates the strength of a coordinated response to infectious disease threats that occur outside of our borders," said CDC Acting Director Jay Bhattacharya in a statement.

"I am grateful for the world-class team at CDC, whose dedication and swift action helped identify potential exposures, provide clear guidance, and protect the American people. As a result, we prevented any new cases from arising in the US."

What Is Hantavirus?

According to the WHO, hantaviruses are zoonotic viruses that naturally infect rodents and are occasionally transmitted to humans.

Globally, an estimated 100,000 to 200,000 hantavirus infections occur each year, with the majority reported in Asia, particularly China. Most cases are sporadic or occur in small clusters linked to contact with infected rodents.

In humans, hantavirus infection can cause severe disease and may be fatal, although the clinical presentation varies depending on the virus strain and geographic region.

How Does Hantavirus Spread?

Hantavirus is primarily spread through contact with infected rodents, including exposure to:

• Urine
• Droppings
• Saliva
• Less commonly, scratches or bites from infected rodents.