Bacterial vaginosis (BV) during pregnancy
A Surprising Infectious Disease Link To Gene Hackman's Death
The mystery surrounding the tragic death of actor Gene Hackman and his wife was solved this week when officials announced that his wife died of a rare infectious disease and Hackman of complications from Alzheimer's disease and heart disease. But did you know that his death may also be linked to an infectious disease?
What happened to Gene Hackman and his wife?From media reports, the famous actor had been suffering from Alzheimer's. As is common in people with advanced dementia, he had withdrawn from public life and required intensive home support. On February 26, both he and his wife were found dead. An intensive, highly public investigation followed.
The conclusion of the investigation: Hackman's wife likely died on February 11, 2025, of an infection unique to the desert southwest, Hantavirus.
Hantavirus is similar to the well-known (and feared) Ebola virus. It is a viral hemorrhagic fever that first causes flu-like symptoms; it makes blood vessels leaky and leads to death from pneumonia and other organ failure. Unlike Ebola, hantavirus is primarily acquired from contact with the physical environment (specifically, contact with rodent feces or urine) and is not transmitted person-to-person.
The official report states that Hackman died of heart disease about seven days after his wife. I do not have any direct knowledge of this case, but this sounds to me more like a heart attack was the final mechanism of death. The underlying cause of his death was advanced dementia from Alzheimer's, which required full-time care. Once that care ceased, he died, with the final event being a heart attack.
Can Gene Hackman's Death Be Linked to an Infection?
Alzheimer's remains a critical area of research because we lack accurate diagnostic tests, effective monitoring tools, or highly effective treatments. The most important pathway to tests and treatments is understanding why people develop Alzheimer's.
Increasingly, researchers believe that infectious diseases may be a cause or contributor. Emerging research suggests that different types of infections lead to inflammation in the brain and or immune responses that lead to dementia.
Below, I describe two of the leading theories.
Source: NIH/National Institute on Aging
Neuroinflammation and infectionsInfections by viruses (herpes simplex virus 1, varicella zoster virus) and by bacteria that cause gum disease have been linked to inflammation in the brain.
One hallmark of Alzheimer's is a fragment of proteins known as Amyloid-beta (Aβ). These fragments clump into plaques that damage neurons and blood vessels in the brain. The theory is that Aβ and another damaging protein called Tau are byproducts of the immune system fighting these infections. Alzheimer's may be an unintended consequence of the body's attempt to fight off viruses and bacteria.
Adding to this is the possibility that a genetic variant (the APOE ε4 allele) may make people more susceptible to herpes simplex virus-1 (the virus that causes cold sores), which may increase Alzheimer's risk.
Lifetime Impact of InfectionsAnother possibility is that repeated infections over a lifetime lead to cumulative brain damage, increasing the risk of AD or other forms of dementia.
In one study involving hundreds of thousands of people from Finland and the UK, researchers found that severe infections requiring hospital treatment were associated with a long-term increased risk of dementia, including vascular dementia and Alzheimer's.
Another study in Denmark analyzed data from 1.4 million people over 40 years to evaluate the association between recurrent severe infections and dementia. They found a clear dose-response relationship: the more episodes of severe infection you have in your lifetime, the higher your risk of developing dementia.
We do not know the exact reasons why this happens. Researchers hypothesize that infections trigger inflammatory cascades that can cross the blood-brain barrier, particularly when recurring frequently.
What does this mean for your health?Prompt treatment of infections and certain vaccines may help protect against the development of Alzheimer's and other forms of dementia. In a future blog post, I'll discuss how this affects the decision to get the shingles vaccine.
There are many reasons to stay up-to-date on your vaccines, especially with measles resurging, and to seek prompt medical attention for symptoms of severe infection. And, as we learn more about the death of Hackman and his wife, keeping your brain healthy may be one additional reason.
Scientists Track Pneumonia-causing Bacteria As They Infect The Blood Stream
Bacteremia, or blood poisoning, occurs when bacteria overcome the body's immune defenses.
Bacteremia can worsen into sepsis, a condition that accounts for more than 1 in 3 hospital deaths per year.
Yet people are routinely exposed to and fight off bacteria from the environment without this deadly series of events occurring.
Scientists are trying to figure out exactly how bacteria spread throughout the body to cause systemic infection in the hopes of eventually stopping this process in its tracks.
Michael Bachman, M.D., Ph.D., clinical associate professor of pathology and microbiology and immunology at U-M Medical School and former postdoc Caitlyn Holmes, Ph.D., have tried to solve this mystery, focusing on gram negative bacteria like Klebsiella pneumoniae, a common source of pneumonia-initiated bacteremia.
In previous work, they determined that bacteria spread in three phases: infection of an initial site, such as the lungs; entrance into the bloodstream; and finally, replication and avoidance of filtration by the liver and spleen.
Traditionally, analyzing a bacterial infection is done by culturing tissue and counting the number of resulting bacteria.
"Experimentally, we can measure the first phase pretty easily in terms of how the bacteria infect the lungs and we can measure the third phase pretty easily in terms of how the bacteria survive in these blood-filtering organs and whether they replicate or not. But that transition out of the lungs and into the bloodstream has traditionally been difficult to measure," said Bachman.
Using an innovative barcoding-style system developed with colleagues at Harvard University, Bachman, Holmes and their team were able to label bacteria with short snippets of DNA in mouse models and use computer analysis to track the movement of K. Pneumoniae throughout the body.
They expected that the bacteria would replicate in the lungs until such a point that their clones overwhelmed the lung's defenses, spilling out into the blood stream, says Bachman.
And while they did see this type of spread -- which they called metastatic dissemination -- there was evidence of another type as well.
Unexpectedly, "about half of the mice had the metastatic pattern, and the other half contained bacteria that escaped on their own into the bloodstream without the need to replicate to large numbers first," Bachman explained about this second mode, which they called direct dissemination.
Overall, metastatic pathway correlated with a stronger infection than the direct route.
Furthermore, over time, infection progressed to more of the metastatic pattern.
"We need to understand the biology of each of these routes in order to figure out the best treatments," said Bachman.
"There's a mantra in infectious disease that is to find and treat the source to stop the bacteremia."
Uncovering the existence of the direct route may mean that bacteria are setting up low level reservoirs in other parts of the body that could be better targeted to treat blood infections.
Additionally, Holmes created mutations in both the K. Pneumoniae and mice that affected the mode of dissemination hinting that the interaction between the bacteria and the host's immune system may determine the outcome of the infection.
"The project began with a very basic question -- how does bacteria leave the lungs -- that we have now provided some insight into, closing a significant gap in our knowledge," said Holmes.
What Do Skin Infections Look Like?
A skin infection occurs when parasites, fungi, or germs such as bacteria penetrate the skin and spread. This can cause pain, swelling, and skin color changes.
Skin infections are different from rashes. A rash is an area of swollen or irritated skin. While rashes can be symptoms of some skin infections, a person with a rash does not necessarily have an infection.
There are four types of skin infections:
Some skin infections require medical treatment. People can manage others with over-the-counter (OTC) solutions or home remedies. Read on to learn more about common skin infections.
This common bacterial skin infection occurs when bacteria infect the deep layers of skin and nearby tissues.
According to the American Academy of Dermatology, doctors diagnose 14.5 million cases of cellulitis in the United States each year.
Cellulitis can lead to serious complications, and receiving early treatment is important.
Symptoms
Cellulitis causes the affected area to swell and change color. On lighter skin, cellulitis may appear red or pink, while on darker skin tones, it may appear purple, brown, or darker than the surrounding area.
Other skin changes may not be well-defined, and it may be difficult to tell where they end. The area will likely be hard and warm to the touch.
Cellulitis can develop anywhere on the body. In children, it commonly affects the face, and in adults, it often appears on the lower legs.
Treatment
Early treatment is key to a successful outcome. If a person does not receive treatment, cellulitis can lead to blood infections and damage the immune system.
The standard treatment is oral antibiotics. Some people may need to take this medication intravenously.
A person should also rest, elevate the affected area, and cover the area to aid healing.
Warts are noncancerous skin growths that occur when a virus infects the top layer of skin.
Warts are transmissible. A person can get them by touching a wart directly or coming into contact with something the wart has touched.
Symptoms
The exact appearance of a wart may depend on the type a person has. Below are some examples:
Treatment
Around 2 in 3 warts will go away by themselves within two years. However, some warts may grow or spread to other areas without treatment.
Treatments for warts may include:
The most suitable treatment may vary depending on the type of wart.
The herpes simplex virus type 1 (HSV-1) is responsible for causing a herpes gladiatorum infection on the skin.
According to the World Health Organization, around 64% or 3.8 billion people worldwide under 50 years old have HSV-1 infection.
Though a person can treat an outbreak of herpes, the virus always remains, which means symptoms can return at any time. The virus is also highly infectious, and a person can transmit it any time it is active, even if no symptoms are present.
Symptoms
When herpes gladiatorum flares, it can cause:
Treatment
Doctors may prescribe antiviral medications to manage a person's symptoms. The following types may help to reduce the severity and duration of symptoms:
A yeast infection develops when a fungus grows out of control. Yeast infections can occur across the body, particularly in areas where the skin folds on itself, such as the armpits, groin, and between the fingers.
Yeast infections are also common in other areas that trap moisture, such as the vagina and mouth.
Symptoms
Symptoms of a yeast infection include the formation of a rash and localized itchiness. Some yeast infections can cause blisters or pustules.
Yeast infections appear differently in different areas of the body. For example, a diaper rash that results from a yeast infection may appear as areas of chafed, differently colored skin and not feature any blisters.
Treatment
A person may be able to treat a yeast infection with OTC antifungal creams and ointments. Some yeast infections on the skin may require prescription medication and creams.
Anyone with a yeast infection on the skin should keep the area as clean and dry as possible while the infection resolves.
Lice are tiny insects that live in hair and cause a parasitic infection of the scalp. They exist worldwide and can affect anyone. Contrary to popular belief, lice can live in any type of hair, regardless of how often a person washes it.
Lice spread easily, especially in crowded conditions such as schools and nursing homes. Though a nuisance, lice do not cause serious health issues.
Symptoms
As with many other skin infections, itchiness is the most common symptom of lice. It can take 4 to 6 weeks for the itchiness to start. Even after treatment, several weeks may pass before this feeling goes away.
A person may be able to see lice in their hair. Nits, or eggs, are small and attach at the base of hairs. People may initially confuse nits with dandruff.
When the eggs hatch, the lice are called nymphs. In this stage, a person may notice small, fast-moving mites on their scalp. Adult lice are about the size of sesame seeds and are light gray or tan.
Treatment
A person can treat lice at home but should speak with a healthcare professional before doing so.
Treatment typically involves combing the lice and their eggs out of the hair and applying medication that kills the lice and their eggs.
Scabies is another parasitic skin infection. When a person has scabies, mites burrow into the upper layer of skin to lay their eggs, causing infection and irritation.
Scabies spreads through prolonged skin-to-skin contact. People living in crowded conditions, such as nursing homes, are most likely to experience outbreaks.
Symptoms
Scabies causes a pimple-like rash that may contain small blisters and areas of scaling. These rashes may appear red or pink on light skin and brown or black on darker skin.
People with scabies may notice burrows in the skin, and small sores and scales. These skin complaints may cause irritation and feel itchy.
Rashes from scabies can appear nearly anywhere on the body. Some of the most common sites include the:
Treatment
Scabies treatment involves medications called scabicides. These kill adult mites, and some also kill the eggs. Tested and approved scabicides are only available on prescription.
Since scabies can spread quickly within households and other indoor settings, close contacts of a person with scabies may also require medication.
Since many skin infections are easy to contract, people should use caution in public areas.
For example, wearing shoes in public bathrooms and showers can help prevent athlete's foot, which is a common fungal infection. Avoiding physical contact with people who have scabies or an active herpes infection can help prevent exposure.
People with skin infections should take precautions and avoid physical contact until symptoms are gone or their doctor clears them to do so.
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