If hand sanitisers kill 99.99% of germs, then who are those 0.01% who survive? There are three major kinds of germs which remain active even when you have used your sanitiser.

Norovirus

Among them, is the norovirus that causes diarrhoea and vomiting outbreaks in places like cruise ships and schools. It is superior to many other viruses because it has a protein capsid, which is resistant to the effects of alcohol.

Norovirus is a group of viruses that causes common illnesses and is also very contagious. It is especially active in the colder month and comes back seasonally. The first norovirus outbreak occurred in Norwalk, Ohio, USA, in a school in 1968, this is where it gets it name from.

Enterococcus faecium

The next on the list is enterococcus faecium, and it lives in the gut. As per a 2024 study titled Enterococcus faecium: evolution, adaptation, pathogenesis and emerging therapeutics, published in Nature journal, it is a Gram-positive bacterium that is a core member of the intestinal microbiota of humans and animals and an opportunistic pathogen that causes life-threatening infections, particularly among hospitalized patients. It mutates in a way that it absorbs carbohydrates and forms a gooey, slime-like substance called the biofilm, which makes it resistant to alcohol.

Clostridium Difficile

Another one is clostridium difficile. This is responsible for causing horrendous diarrhoea and vomiting in hospitalised patients. It also has a remarkable ability to respond to environmental stressors including alcohol gel by going to sleep. It produces spores and allows all metabolic activity.

Clostridium difficile (C. diff) is a type of bacteria that can cause colitis, a serious inflammation of the colon. Infections from C. diff often start after you've been taking antibiotics. It can sometimes be life-threatening.

Why Do You Label Read 99.99%?

Apart from the germs and pathogens, another reason why your label reads that it kills 99.99% is to avoid any legal hassles. If someone uses a specific product and falls sick, then the person cannot sue the company as the company did not give a 100% safety guarantee against the germs.

A better way to be healthy is always to clean your hands with soap and water and wear gloves wherever is possible.

White sugar is widely known for its harmful effects on health. As a result, many people—especially those with Type 2 diabetes—turn to low- and no-calorie sweeteners such as aspartame, saccharin, and erythritol, believing they are a healthier alternative.

However, a new study published in Neurology, the medical journal of the American Academy of Neurology, has again suggested that higher consumption of certain artificial sweeteners may be associated with faster declines in memory and thinking skills over time.

The researchers stressed that the findings do not prove these sweeteners cause cognitive decline. Instead, they show an association, meaning other factors could also contribute to the observed pattern.

"Low- and no-calorie sweeteners are often seen as a healthy alternative to sugar. However, our findings suggest certain sweeteners may have negative effects on brain health over time," said study author Claudia Kimie Suemoto from the University of São Paulo, Brazil.

What Did the Study Find?

The study followed 12,772 adults in Brazil, with an average age of 52 years, for approximately eight years. Researchers examined the intake of seven commonly used low- and no-calorie sweeteners:

• Aspartame
• Saccharin
• Acesulfame K
• Erythritol
• Xylitol
• Sorbitol
• Tagatose

These sweeteners are commonly found in ultra-processed foods and beverages, including flavored water, soft drinks, energy drinks, yoghurt, desserts, and products marketed as low-calorie. Many are also sold separately for use in coffee, tea, cooking, and baking.

The researchers found that people with the highest total intake of sweeteners experienced a 62% faster decline in overall thinking and memory abilities than those with the lowest intake. This difference was estimated to be comparable to about 1.6 additional years of brain ageing.

Participants in the middle consumption group also showed a 35% faster decline, equivalent to approximately 1.3 additional years of ageing.

The association was especially strong among people with diabetes, who are more likely to use artificial sweeteners as sugar substitutes.

Stronger Link in Adults Under 60

Age also appeared to influence the findings. Among participants younger than 60, those who consumed the highest amounts of sweeteners experienced faster declines in verbal fluency and overall cognitive performance than those with the lowest intake.

Researchers did not observe the same association among participants aged 60 years and older. The study found that aspartame, saccharin, acesulfame K, erythritol, sorbitol, and xylitol were associated with faster declines in overall cognition, particularly memory. Tagatose was the only sweetener not linked to cognitive decline.

"While we found links to cognitive decline for middle-aged people both with and without diabetes, people with diabetes are more likely to use artificial sweeteners as sugar substitutes," Suemoto said. "More research is needed to confirm our findings and to investigate if other refined sugar alternatives, such as applesauce, honey, maple syrup or coconut sugar, may be effective alternatives."

Are There Any Limitations?

The researchers also acknowledged several limitations in study :

• It did not evaluate every artificial sweetener currently used in foods and beverages, so the findings cannot be applied to all sugar substitutes.
• Dietary intake was self-reported, meaning participants may have inaccurately remembered or estimated what they consumed.
• The study was observational, meaning it identified an association but cannot establish that artificial sweeteners directly caused cognitive decline.

Brain disorders are becoming one of India's fastest-growing public health challenges, said health experts ahead of Brain Day on July 22.

The experts highlighted that an ageing population, rising lifestyle diseases and limited access to specialist care are contributing to an increasing burden of conditions such as stroke, epilepsy, Parkinson's disease, dementia and multiple sclerosis.

Access Gap Delays Diagnosis, Treatment

Dr. Madhukar Bhardwaj, Director & Head of Department, Neurology, Aakash Healthcare, said neurological disorders have become one of India's most urgent healthcare concerns.

"Neurological disorders are no longer a concern of a small section of the population—they are one of the most pressing emerging healthcare challenges of our time. In a country as vast and diverse as India, with a rapidly ageing population, this is a matter of urgency. What makes the situation even more worrying is the lack of equitable access to care," he said.

According to the World Health Organization's Global Status Report on Neurological Disorders (2025), India faces a severe shortage of neurologists, with the neurologist-to-patient ratio nearly 80 times worse than in high-income countries, leaving specialist care concentrated in major cities.

Stroke Increasingly Affects Younger Adults

Experts also highlighted a worrying shift in disease patterns, with strokes increasingly affecting younger people. Dr. Bhardwaj said strokes, once considered a disease of older adults, are now being seen more frequently among people in their 30s and 40s, underscoring the need for greater awareness and prevention.

Lifestyle Diseases Driving Brain Disorders

Doctors identified uncontrolled hypertension, diabetes, obesity, smoking, chronic stress, physical inactivity and poor sleep as major contributors to the rising burden of neurological diseases.

Dr. Rajas Deshpande, Consultant and Head of Neurology, Jupiter Hospital, Pune, said many neurological conditions share common lifestyle-related risk factors.

"Controlling hypertension, diabetes, obesity, smoking and physical inactivity can significantly reduce the risk of stroke and vascular dementia. Prevention deserves as much attention as treatment because many neurological disorders share common modifiable risk factors," he said.

Early Diagnosis Can Improve Outcomes

Dr. Bhardwaj stressed that many neurological disorders progress silently, making early diagnosis critical.

"Whether it is stroke, epilepsy, Parkinson's disease or memory disorders, early diagnosis can significantly improve outcomes. Unfortunately, many patients seek specialist care only after the disease has advanced, either because symptoms are ignored or because neurological services are not easily accessible. Greater public awareness and timely referrals are essential," he said.

Brain Health Linked to Women's Reproductive Health

Experts also emphasized that brain health extends beyond cognition. Dr. Hrishikesh Pai, Consultant Gynecologist & IVF Specialist, Lilavati Hospital Mumbai and Fortis Hospitals Delhi & Chandigarh, said the brain plays a central role in regulating women's reproductive health.

"Brain health plays a critical role in women's reproductive health. The hypothalamus and pituitary gland in the brain regulate the hormonal signals that control menstruation, ovulation, and pregnancy," he said.

He added that chronic stress, neurological disorders, pituitary diseases and certain medications can disrupt hormonal balance, leading to irregular menstrual cycles, infertility and pregnancy-related complications.

As wildfire smoke continues to affect communities across North America and Europe, fertility experts are recommending people undergoing vitro fertilization (IVF) to pay attention to an overlooked factor before embryo implant: air quality.

A new study suggests that exposure to unhealthy levels of air pollution, particularly from wildfire smoke, could significantly reduce the chances of a successful pregnancy after IVF.

Researchers, therefore, recommend discussing the timing of embryo transfer with a fertility specialist when air quality deteriorates.

Wildfire Smoke May Interfere With Embryo Implantation

The study, published in the journal Human Fertility, indicates that air pollution may affect reproductive health.

Between June and July 2023, researchers from Northwell Fertility in New York examined 190 fresh and frozen embryo transfers, when smoke from massive Canadian wildfires caused hazardous air quality across the northeastern United States.

They then compared the rate of successful pregnancies based on the Air Quality Index (AQI) on the day of embryo transfer.

Clinical pregnancy rates were approximately 62% on days with good air quality and 65% on days with moderate air quality.

But when the AQI rose above 100, a level considered unhealthy for sensitive groups; the pregnancy rate dropped to just 27%.

Although only 11 embryo transfers took place on days with unhealthy air quality, the researchers say the findings raise concerns about whether temporary exposure to wildfire smoke could affect one of the most critical stages of IVF.

Also read: Miles Apart, But Planning A Family Together: The Fertility Reality Of Long-Distance Marriages In India

How Can Air Pollution Affect Fertility And IVF Success Chances?

IVF embryos are created and stored in strictly controlled laboratories, meaning they are protected from polluted air and other contaminants in the environment.

Instead of damaging the embryo, researchers believe that wildfire smoke can affect the woman's body by increasing inflammation and oxidative stress. This could create a less favourable environment for the embryo to implant in the uterus.

Air pollution contaminant, PM2.5, a fine particulate matter, is one of the main pollutants in wildfire smoke. It is minute enough to enter the lungs, bloodstream, and trigger inflammatory responses throughout the body.

Previous studies have already indicated that PM2.5 exposure could cause pregnancy complications and harm fertility.

Dr. Randi Goldman, Program Director at Northwell Fertility and co-author of the study, said the research suggests patients and physicians should consider environmental conditions when planning embryo transfer.

Also read: Global Female Infertility Could Affect 80 Million Women Aged 35+ by 2036: Lancet Study

"The embryo is safely protected inside the laboratory. The effect we're seeing is more likely related to how air pollution influences the body before and after embryo transfer rather than the embryo itself," Goldman said.

She opines that patients experiencing severe wildfire smoke or hazardous air quality should discuss whether delaying embryo transfer by a few days could improve the chances of success.

"Patients invest enormous emotional, physical and financial resources into IVF. Delaying treatment is difficult, but when air quality reaches unhealthy levels, it may be worth discussing timing with your fertility specialist," Goldman said.

Expert-Recommended Tips To Improve IVF Success

Adopt a Fertility-Boosting Lifestyle: Eat a balanced diet, exercise daily, and enjoy a healthy BMI. Reduce alcohol intake, do not smoke, and avoid recreational drugs.

Take Key Supplements: Folic acid, CoQ10, and vitamin D can improve egg quality and overall fertility.

Stress Management Is Key: Elevated cortisol levels can affect reproductive hormones. Practice mindfulness, yoga, or acupuncture.

Sleep Well: Aim for at least 7–8 hours of restful sleep to support hormonal balance.

Address Underlying Health Conditions: Conditions such as PCOS, thyroid issues, and endometriosis can interfere with fertility outcomes if left unmanaged.

Start Early, If Possible: The earlier IVF is initiated—especially for women over 35—the better the chances.