The Problem with Ignoring Infectious Disease in Chronic Health

By Molly Cavanaugh, July 2025

Robert F Kennedy Jr, RFK, was sworn in as the 26^th Secretary of the U.S. Department of Health and Human Services on February 13, 2025 (1 ). Since his appointment, RFK has launched his program “Make America Healthy Again” with a focus on chronic diseases such as autoimmune diseases, cancer, and mental illness . The White House claims that too much money has been spent on infectious disease when we can solve chronic diseases with alternative methods (2). Chronic disease is indeed a huge issue in the US. As of 2022, chronic disease accounted for 90% of health care costs and impacting 6 in 10 Americans (3). Wanting a healthier America and to combat chronic disease is a noble goal, but our problems cannot be solved simply through diet and exercise.  In fact, infectious diseases, including viruses, often play a role in chronic diseases. Here, I will go through a few examples of how viruses are involved in autoimmune diseases, cancer, and mental health.

Autoimmune Diseases:

Autoimmune diseases occur when the body does not recognize part of itself, such as a cell type or tissue, as being self, and marks it as foreign. Essentially, the body is tricked into attacking itself. Viruses have long been linked to autoimmune disorders (4) . Viruses linked to autoimmune diseases include Coxsackie B virus, rotavirus, influenza A, herpesviruses, rubella, and measles (5). Autoimmune diseases linked to viruses include autoimmune myocarditis, multiple sclerosis, rheumatoid arthritis, lupus, and diabetes (6). Because of the myriads of diseases and viruses involved, the links between autoimmune diseases and viruses are still being explored.

Diabetes Type 1 is an autoimmune disease in which pancreatic beta cells, which produce the insulin needed for food processing, are attacked by the immune system, limiting the ability to naturally produce insulin (7). As of 2021, there are 1.7 million Americans living with diabetes type 1, including 4 out of every 1000 children (8). Diabetes Type 1 has a genetic component that makes people with certain genes more likely to develop diabetes. The trigger for developing diabetes is not solely genetic and depends on external stimuli (9). While science has yet to prove directly that viruses can trigger diabetes, there is strong evidence leading to that conclusion.

For example, viruses like Coxsackie B virus, which are a type of enteroviruses that target beta cells and cause diarrhea symptoms, have been found at a much higher rate in diabetic people as opposed to non-diabetic people. In 1997, a study of 12 healthy adults and 12 diabetic adults found Coxsackie B virus in 5/12 diabetic adults but 0/12 healthy adults (10). Coxsackie B virus are also known to directly target and kill beta cells (11). Finally, Coxsackie B virus interacts with the immune system and can alter the host’s response, which can lead to the destruction of pancreatic beta cells (12). Coxsackie B virus is theorized to induce diabetes in genetically susceptible people through several pathways (13). These include the virus mimicking beta cell proteins (tricking the body into thinking that the virus is beta cells and convincing the immune system to invade and attack the real beta cells), causing immune activation throughout the body that leads to inflammation (the immune cells in this case would invade to stop the virus and then damage the beta cells too), or by killing the pancreatic beta cells themselves (14).

Another example of an autoimmune disease influenced by a virus is multiple sclerosis (MS). MS is an inflammatory, demyelinating disease which impacts the brain and central nervous system (15). In MS, part of the neurons, which are responsible for sending information throughout the brain, are damaged as the immune system attacks the protective layer of fat called the myelin sheath. The damage to the neurons results in slowing of information and disabilities (16). Epstein-Barr Virus, EBV, infects 9 in 10 people throughout their life and is known for causing mono, the kissing disease, which can lead to chronic exhaustion and autoimmune problems (17). While EBV used to be known as a relatively harmless virus, recent studies have found a substantial link between EBV and MS. The US military ran a 20 year longitudinal study (tracking the same group of people over an extended period of time) in which it studied the link between EBV and MS. This study found that those infected with EBV are 32x more likely to develop MS than those who are not (18). This study also importantly did not find this same association with any other virus. While this study did not show that MS is caused by EBV, it provides the strongest evidence thus far that it is.

Cancer:

Cancer is the uncontrolled growth of abnormal cells (19). This is often due to dysregulation in the cell cycle. This dysregulation can be caused by several different factors, including viruses called oncoviruses. The most famous example of a cancer causing virus known to dysregulate the cell cycle is human papillomavirus, HPV (20). This is a double-stranded DNA virus which causes over 95% of all cervical cancers (21). 37,800 people in the US are diagnosed with cancer caused by an HPV infection each year (22). While HPV most frequently is known to cause cervical cancer, it can cause many cancer types in both men and women ranging from oropharyngeal cancer to penile cancer (23). There is a highly effective vaccine against HPV that should be given before puberty to protect teens into adulthood. Cervical cancer rates drop from an average of 8.4 cases per 1000 women to 3.2 cases per 1000 women when comparing unvaccinated to vaccinated women (24).

HPV is not the only virus which can cause cancer. Human cytomegalovirus, CMV, is a double stranded DNA virus which infects 1 in 3 children by age 5 and around 50% of US adults by age 40 (25). Infections typically resemble a mild cold, if they are noticed by the human host at all. After the initial infection, CMV says latent, hiding in the cells of the host and can reemerge later in life to cause issues, most importantly, cancer. CMV has been strongly associated with various types of cancer including breast cancer and colorectal cancer for several decades (26). Like diabetes, while there is a genetic link associated with many types of cancer, there can also be outside pressures like CMV involved in the development of cancer. One way that CMV can induce cancer is that CMV encodes proteins that have a specific job- to prevent apoptosis (27). Apoptosis, a way that the body naturally kills unwanted or mutated cells, is a cellular defense against cancer. Typically when a cell behaves in a way that it should not, like during cancer when there is uncontrolled growth, those cells would be marked for death by apoptosis (28). However, CMV prevents apoptosis, leading to the uncontrolled division and replication of cells: cancer.

There are other molecular mechanisms by which CMV may be contributing to cancer by silencing host defense genes and changing the normal cell cycle. Research is still being conducted to uncover the direct paths in which CMV can induce cancer, and how we can prevent CMV infections. What is clear, is that there is a strong correlation between CMV and cancer. In fact, between 90%-100% of breast, colon, prostate and ovarian cancer patients are found to have CMV proteins (29). Does this mean that CMV caused all of those cancers? No, but it is absolutely a risk factor that cannot be ignored. We know that smoking can cause cancer, so we prevent this risk factor to prevent cancer. If we can prevent CMV infections, we can prevent cancer.

There have been 8 virus groups linked to cancer: HPVs, Epstein-Barr virus, hepatitis B, hepatitis C, human immunodeficiency virus, Human herpes virus 8 or Kaposi’s sarcoma herpesvirus, Human T-lymphotrophic virus-1, and Merkel cell polyomavirus (30). HPV, Epstein-Barr virus, and Merkel cell polyomavirus all infect between 70-100% of the adult population, meaning that almost every adult in the US has a virus which is considered to be a risk factor for developing cancer (31, 32, 33). It is estimated that between 15-20% of all cancers are triggered by an infection by a virus (34). Each year, as of 2021, there are 1.9 million new cancer cases in the US and nearly 610,000 deaths (35). Using the estimated amount of cancer caused by virus, up to 91,000 American lives could be saved yearly by preventing cancer causing viruses, not to mention the 285,000 cancer cases that could be prevented entirely.

Mental health: 

Human Immunodeficiency Virus, HIV, infects 39.9 million people across the world as of 2023, with 1.3 million new infections in the same year (36). There are an estimated 1.2 million Americans living with HIV as of 2022 (37). HIV is a single stranded RNA retrovirus which currently has no cure but does have an effective medication, anti-retroviral therapy (ART), which can suppress HIV replication and symptoms (38). ART has been ground-breaking as it allows people living with HIV to live normal lives and not spread HIV even to sexual partners. That said, around 50% of people living with HIV, equating to 600,000 Americans, who are on ART still have neurological symptoms (39). This is known as HIV associated neurocognitive disorder (HAND) and symptoms include both depression and dementia. While the exact mechanisms that cause the virus to impact mental health are being explored, it is known that HIV causes inflammation of the brain and damage to various cells in the brain by activating the immune system (40). HIV is not the only virus that impacts mental health. In fact, it has long been theorized that viruses are the link for many mental health conditions (41).

There is also evidence linking herpes simplex virus 1, HSV-1, to Alzheimer’s disease. HSV-1 is increasingly common, as of 2020 it infects 64% of the world’s population under 50 (42). HSV-1 is the main cause of oral herpes while occasionally causing genital herpes as well. HSV-1 is spread through skin to skin contact and is most often spread during childhood. While the initial infection may resemble a cold or flu, the virus then stays hidden and pops up in the form of cold sores in moments of stress or due to other triggers. Alzheimer’s disease is marked with distressing symptoms including severe memory issues and shrinking of brain tissue (43). The changes within the brain of people living with Alzheimer’s disease has been well characterized as an accumulation of tau, a protein which is involved in the structure of cells and fibers in the brain, and beta-amyloids, a byproduct of the amyloid precursor protein which has functions in keeping the brain functioning properly.  (44,45). In simple terms, these proteins—normally present in healthy brains— are not properly cleared in Alzheimer’s disease. As they accumulate, they disrupt brain function, leading to neuron death and eventually causing the brain to shrink.

How can HSV-1, which frequently presents as cold sores, be related to the accumulation of harmful proteins in the brain that lead to Alzheimer’s disease? HSV-1 was first linked to Alzheimer’s disease in the 1990s when HSV-1 was discovered in the brain of people who died of Alzheimer’s disease (46). HSV-1 was found to be associated with higher rates of a protein called APOE-ε4, which is a known risk factor for developing Alzheimer’s disease. Today, one theory around how HSV-1 plays into Alzheimer’s disease deals with a special type of genes called transposons. Transposons are sections of DNA that can move around in the genome to turn genes on and off (47). It is important that genes can be turned on and off to respond to the environment and stressors. For example, when the body is digesting food, the gene for insulin must be turned on but when the body is not digesting food insulin must be turned off or you will get sick (48). HSV-1 has been shown to be associated with dysregulation in transposon elements. This dysregulation can lead to an increase in inflammation and genes turning on or off incorrectly. Finally, HSV-1 is shown to increase both beta-amyloids and tau, hallmarks of Alzheimer’s disease. (49, 50).

There are 6.9 million Americans living with Alzheimer’s disease (51). If 64% of them have HSV-1, then 4.4 million Americans have both Alzheimer’s disease and HSV-1. While the link between HSV-1 and Alzheimer’s disease is still being explored, there is strong evidence to conclude that HSV-1 is involved, at least sometimes, in Alzheimer’s disease. We must explore this connection further to determine how we can target HSV-1 and what we can do to prevent future cases of Alzheimer’s disease. What other viruses have an impact on mental health? These studies are still underway, if the grants have not been canceled, and the data is of critical importance. 

The link between viruses and chronic health is clear, but many of the ways that viruses influence these chronic diseases are still under investigation. RFK Jr is right to work towards a healthier America, but cutting funding across the board for infectious disease will lead to worse health outcomes across the board. Other health factors such as exercise and quality of food absolutely play a role in both infectious and chronic disease. That said, infectious disease also plays a role that cannot be ignored. How do we focus on chronic disease without first considering how infectious disease plays into chronic disease? If we stop vaccinating against HPV, cancer rates will rise and autism levels will remain unchanged. If we stop funding HSV-1 research, we may lose a chance to prevent Alzheimer’s disease later in life. Health is too complicated to separate into distinct groups like infectious vs chronic. We must continue to fund health research and see the connections as science unravels them.