Experiencing daytime sleepiness is something that is usually perceived as a minor inconvenience, but for older adults, it could be an early warning sign of Dementia. This neurodegenerative disease leads to the progressive decline of brain cells. This eventually

affects memory, cognition, and personality, making everyday tasks more difficult. As one of the fastest-growing neurological disorders across the world, dementia poses a significant health threat to ageing populations.

Is Dementia Linked To Poor Sleep?

For this study, researchers followed 445 older adults (average age 76) over three years, aiming to determine whether poor sleep could increase the risk of mild cognitive impairment (MCI), which often leads to dementia. At the start, none of the participants had MCI, but by the end of the study, 36 individuals had developed the condition.

The researchers discovered that participants with poor sleep were more likely to develop MCI compared to those who slept well. However, when depression symptoms were taken into account, the link between poor sleep and MCI became less pronounced, suggesting that while sleep issues are a concern, mental health also plays a key role in dementia risk.

To assess sleep quality, the Pittsburgh Sleep Quality Index (PSQI) was used, evaluating factors such as sleep duration, disturbances, and daytime alertness. Among these, "daytime dysfunction"—defined as excessive sleepiness and low energy during the day—was most strongly associated with an increased risk of MCI. Those experiencing daytime dysfunction were more than three times as likely to develop MCI as those who didn’t report such symptoms.

There are many types of dementia:

Dementia is not a specific disease. According to the Centers for Disease Control and Prevention (CDC), it is an overall term that describes a decline in mental ability that interferes with daily life. People with dementia often have symptoms like trouble remembering, thinking, or making everyday decisions. These symptoms tend to get worse over time.

Alzheimer’s disease is the most common type of dementia, and it mostly affects the elderly. Each form of dementia has a different cause. Though dementia mostly affects older adults, it is not a part of normal ageing. An estimated 6.7 million older adults have Alzheimer's disease in the United States. That number is expected to double by 2060, as per data from the CDC.

In 2022, 3.8% of men and 4.2% women in US were diagnosed with dementia. The percentage of people increase with age from 1.7% for those aged 65-74 to 13.1% for those aged 85 and older. Alzheimer's accounts for 60 to 80% of all dementia cases and it is most prevalent in California, Florida, and Texas, as these states have the highest number of people.

The US Centers for Disease Control and Prevention (CDC) and the UK Health Security Agency (UKHSA) have issued travel health advisories warning travelers about the growing risks of mosquito-borne diseases, including chikungunya and yellow fever.

The CDC has issued a Level 2 Travel Health Notice for Costa Rica following a chikungunya outbreak, while UK health authorities have alerted travelers about rising imported chikungunya cases and yellow fever activity across multiple countries.

CDC Issues Level 2 Travel Health Notice

The CDC warned American travelers to "practice enhanced precautions" after Costa Rica reported a chikungunya outbreak.

On July 1, Costa Rica's Ministry of Health declared an active outbreak in the oceanside community of Playa Langosta in the western province of Guanacaste..

An epidemiological survey identified 45 suspected cases, of which four were laboratory confirmed, while 17 others were considered likely linked to the outbreak.

According to the US Embassy in Costa Rica, the cases include both Costa Rican nationals and foreign visitors. The embassy said local transmission means the virus is now circulating among the local mosquito population rather than being limited to infected travelers.

Costa Rica has reported 16 total cases this year, with the previous reported case dating back to 2017.

UKHSA Warns Over Rising Chikungunya Cases

The UK Health Security Agency issued a warning for holidaymakers travelling to affected regions as imported chikungunya cases continue to rise.

"Are you, or someone you know, heading off on a tropical trip? It's worth being aware of chikungunya, a mosquito-borne virus that can cause severe joint pain. Check out our blog post to learn how to stay protected," the UKHSA said in a post on X.

UKHSA reported 112 confirmed and probable chikungunya cases among travelers returning to England, Wales and Northern Ireland in 2024—almost one and a half times the number reported in 2023.

"Travel to India accounted for the majority of these cases, followed by travel to Pakistan and Brazil – all popular destinations for people travelling from the UK," the agency added.

Yellow Fever Alert Issued for Multiple Countries

The UK government-backed Travel Health Pro has also warned travelers about increasing yellow fever activity.

Since the beginning of 2026, 95 confirmed yellow fever cases have been reported globally.

Confirmed cases have been reported in:

• Bolivia
• Brazil
• Colombia
• Ecuador
• Peru
• Venezuela
• Burkina Faso
• Central African Republic
• Cameroon

What Is Chikungunya?

Chikungunya is a mosquito-borne viral disease transmitted primarily by Aedes aegypti and Aedes albopictus mosquitoes, the same mosquitoes that spread dengue fever.

Symptoms usually appear three to seven days after an infected mosquito bite and include:

• Sudden fever
• Severe joint pain
• Headache
• Nausea
• Fatigue
• Rash (in about half of cases)

Unlike dengue, chikungunya can leave lingering effects, with joint pain and fatigue lasting for weeks, months or even years.

People at higher risk of severe illness include:

• Newborns
• Older adults
• People with hypertension
• People with diabetes
• People with heart disease

The mosquitoes responsible for spreading chikungunya commonly breed in stagnant water found in overhead tanks, coolers and unused containers.

What Is Yellow Fever?

Yellow fever is a viral disease transmitted through the bite of infected mosquitoes. The infection can be severe and may become fatal in some cases if not managed appropriately. Vaccination is recommended before travelling to certain affected regions.

Initial Symptoms

• Fever
• Chills
• Severe headache
• Back pain
• General body aches
• Nausea
• Vomiting
• Fatigue
• Weakness

Severe Symptoms

• High fever
• Yellowing of the skin or eyes (jaundice)
• Bleeding
• Shock
• Organ failure

The US Food and Drug Administration (FDA) has identified a new Cyclospora outbreak, which is not related to ongoing outbreaks in the country causing watery diarrhea and hospitalizations among thousands.

The agency said the outbreak has sickened 72 people and is linked to an unspecified product. The FDA said the source has "not yet been identified."

The announcement comes as the US continues to report one of its largest cyclospora outbreaks. According to the US Centers for Disease Control and Prevention (CDC), there have been 4,173 laboratory-confirmed and domestically acquired cases of cyclosporiasis across 41 states since May 1.

A total of 308 people with confirmed infections have been hospitalized, but no deaths have been reported.

The CDC also reported 767 travel-associated cases during the same period, resulting in 33 hospitalizations and no deaths. These cases were linked to contaminated food or water consumed outside the US.

Lettuce-Linked Outbreak In 5 states

According to the Michigan Department of Health and Human Services, a Cyclospora outbreak linked to iceberg lettuce distributed by Taylor Farms has sickened 7,664 people across Indiana, Kentucky, Michigan, Ohio and West Virginia, with 160 hospitalizations.

Michigan has reported about 7,000 cases, while Ohio has recorded nearly 3,500 cases, according to the Toledo-Lucas County Health Department.

“I want to stress that our investigation continues, including into other potential sources and commodities for other clusters of illness,” said Kyle Diamantas, acting FDA commissioner. Meanwhile, Health and Human Services Secretary Robert F. Kennedy Jr. this week said the outbreak is “under control.”

Why Is It So Difficult To Find the Source?

Also read: Cyclospora Parasite Outbreak: Why You Should Avoid Packaged Salads and Go For Loose Greens

According to experts, Cyclospora infection caused by the parasite Cyclospora cayetanensis is much harder to trace than common foodborne bacteria such as E. coli and Salmonella.

Investigators typically use DNA fingerprinting to connect bacterial infections to contaminated food through laboratory networks such as PulseNet. However, this method is much less effective for Cyclospora because the parasite has a more complex genetic makeup, making it difficult to link infections to a single food item or supplier.

Dr. Max Teplitski, former head of the Division of Food Safety at the US Department of Agriculture and now chief science officer at the International Fresh Produce Association, said the parasite remains one of the most difficult foodborne pathogens to investigate, contributing to delays in identifying the outbreak source, CNN reported.

How To Prevent Cyclospora Infection

Read More: Cyclospora Parasite Spreads to More US States: Foods to Avoid Right Now

The CDC recommends the following steps to reduce the risk of infection:

• Wash your hands thoroughly with soap and water before and after handling fresh produce.
• Rinse fruits and vegetables under running water before eating, cutting or cooking them.
• Do not rewash produce labeled "prewashed."
• Scrub firm produce, such as melons and cucumbers, with a clean produce brush.
• Cut away bruised or damaged portions before eating.
• Refrigerate cut, peeled or cooked fruits and vegetables within two hours.

Cyclospora spreads through food or water contaminated with human feces and is not transmitted directly from person to person.

Dr. Darien Sutton, an emergency medicine physician and ABC News medical correspondent, emphasized that alcohol-based hand sanitizers are ineffective against the parasite. "This type of parasite doesn't easily go away with alcohol-based hand sanitizer. So, good old handwashing is really key here," Sutton said.

A relentless heatwave is sweeping across parts of Europe, Asia, and Africa, pushing temperatures to dangerous levels and triggering widespread disruptions.

While France and Japan are battling scorching conditions and issuing health alerts, extreme heat in parts of Africa has reportedly killed camels, highlighting the growing human, environmental, and economic toll of intensifying climate extremes.

In addition, countries including Spain, Italy, Greece, Portugal and Germany are also battling extreme heat and wildfire threats, while climate change is worsening wildfire risks in the US and Canada.

France Records Excess Deaths

A deadly heatwave in France in late June led to 5,764 excess deaths, according to updated data released by the country's public health agency.

The revised analysis found that 21,674 people died between June 17 and July 2, compared with the 15,910 deaths normally expected during the same period—a 36% increase in mortality.

Also read: World Brain Day: Climate Change Is Not Just Harming The Planet, It Could Also Be Affecting Your Brain

Japan Heatwave Leaves 14 Dead

Japan is also grappling with extreme temperatures. More than 450 people were taken to hospitals for heat-related illnesses in a single day in Tokyo—the highest daily figure since records began 16 years ago, emergency services said.

The update comes as the country endures a heatwave that has killed at least 14 people over the past week.

UK Issues Heat Health Alerts

The UK has issued yellow heat health alerts across central and southern England, with temperatures forecast to reach 30°C (86°F).

The UK Health Security Agency (UKHSA) warned that the heat is expected to cause minor impacts on health and social care services while increasing risks for vulnerable people. The alerts remain in effect through Sunday as parts of the country continue to experience prolonged dry weather and drought conditions.

Read More: Europe Heatwave Causes 10,000 Excess Deaths; England, Wales Record 2,700 More Fatalities

Camels Struggle To Survive Extreme Heat

Camels, long regarded as the "ships of the desert," are also struggling with extreme heat in Africa.

The BBC reported that camel shepherds in Ethiopia's Afar region have observed blisters on camels' feet, watery eyes, and skin burns caused by scorching sand.

Research from Somalia found drought-related camel mortality affected nearly 46% of camel-owning households, while another study from Algeria reported a significant rise in camel deaths during summer heatwaves.

Scientists say prolonged heat and drought cause stress, dehydration, disease, and reduce access to water and vegetation essential for camel survival.

Europe Continues to Break Heat Records

According to the Copernicus Climate Change Service (C3S), June 2026 was the hottest June ever recorded for western Europe and the second warmest globally.

The World Meteorological Organization (WMO) said the heat has continued into July, fuelling wildfires in France and the Iberian Peninsula. Spain's Fabra Observatory recorded 40.5°C on July 8, the highest temperature in more than a century of observations.

"Heatwaves like this are what we expect to see in a changing climate," said John Kennedy, head of climate information at WMO.

"In the 50 years since the historic heatwave in 1976, Europe as a whole has warmed by around two degrees. It's one of the fastest warming continents and extremes of temperature have increased too."

Why Heatwaves Are So Dangerous

Heat is often called the "silent killer," with an estimated 489,000 heat-related deaths each year between 2000 and 2019.

"Prolonged exposure over several days, particularly when temperatures remain high at night, means the body enters each new day already stressed," said Lachlan McIver, Health Advisor at the WHO-WMO Climate and Health Joint Office.

According to scientists, climate change is driving increasingly severe heatwaves. A recent study by the Potsdam Institute for Climate Impact Research found that warming ocean waters account for 50–64% of the increase in land heatwaves globally.