6 infectious diseases that could pose a threat in 2025

“The COVID-19 crisis may have passed, but a harsh lesson remains: the world is woefully unprepared for the next pandemic,” warned António Guterres, UN Secretary-General, on the International Day of Epidemic Preparedness, December 27, 2024. While the global focus has largely shifted away from pandemic preparedness, emerging threats and resurgent infections continue to pose serious risks.
Declining childhood vaccination rates, rising exemptions from school vaccine requirements, and the ongoing spread of misinformation have created conditions that allow infectious diseases to take hold once again. The appointment of Robert F. Kennedy Jr. as the head of the U.S. The Health and Human Services Department has also raised concerns, given his history of promoting vaccine skepticism. As a result, public health officials are closely monitoring several infectious diseases that could become major threats in 2025.
Here are six infectious diseases to keep an eye on this year:

H5N1 bird flu, also known as avian influenza, is a highly pathogenic virus that primarily affects birds but can also infect humans and other animals. According to the Centers for Disease Control and Prevention (CDC), the virus is known for causing severe disease and high mortality rates in poultry. It spreads among wild aquatic birds and can infect domestic poultry, leading to significant outbreaks. Human infections are rare but can occur through direct contact with infected birds or contaminated environments.

As of February 2025, the Centers for Disease Control and Prevention (CDC) has confirmed 64 human cases of bird flu in the U.S., including the country's first "severe" case in a Louisiana patient who was hospitalized and later died. While the CDC maintains that the overall public health risk remains low, there is ongoing surveillance to monitor the situation. Importantly, there have been no confirmed cases of human-to-human transmission in the U.S.
Dr. Robert H. Hopkins, Jr., medical director of the National Foundation for Infectious Diseases (NFID), reassures the public, stating, "Stay alert, but do not panic. The risk to the public is currently low, and there are steps everyone can take to help protect their own health and prevent the spread of disease."
Measles is another major concern, particularly due to the decline in vaccination rates. This highly contagious viral disease spreads through respiratory droplets and can cause high fever, red eyes, runny nose, and a distinct rash. With a decrease in vaccination rates, Measles saw a global spike.

As of February 28, 2025, the CDC has reported 164 measles cases across nine states, including Alaska, California, and Texas. Three outbreaks have been recorded this year, with 93% of cases linked to these clusters. In comparison, 2024 saw 16 outbreaks, with 69% of cases being outbreak-related. There also has been 1 reported death in 2025 due to the disease.

The World Health Organization (WHO) describes polio as a highly infectious virus that attacks the nervous system, potentially causing paralysis within hours. It spreads primarily through contaminated food or water and multiplies in the intestines. Early symptoms include fever, fatigue, headaches, vomiting, neck stiffness, and limb pain. While there is no cure, the polio vaccine—given multiple times—offers lifelong protection.
Despite the proven effectiveness of the vaccine, RFK Jr. has falsely suggested that polio vaccines caused cancer in his generation, claiming they led to more deaths than polio itself. Meanwhile, President-elect Donald Trump has voiced strong support for the vaccine, emphasizing the need to maintain access.

While there have been no new reports of Polio breaking out in the US, it is still endemic in countries like Pakistan and Afghanistan. Pakistan, just this year, has already reported 6 cases of Polio, while Afghanistan also reported one in February.

Mpox, previously known as monkeypox, is a viral illness caused by the monkeypox virus, which belongs to the same family as the smallpox virus. There are two main strains, or "clades," of the virus: clade I and clade II, with subclades Ia and Ib in clade I, and subclades IIa and IIb in clade II. In 2022–2023, a global outbreak was primarily caused by the clade IIb strain.The disease is still a concern, especially with recent outbreaks in the Democratic Republic of the Congo and other countries, driven by clades Ia and Ib.
In the United States, the first case of clade Ib mpox was confirmed in California in November 2024. This case followed the patient’s travel to an affected area.

While there is no specific treatment for mpox, early care is crucial to manage symptoms such as the painful rash, prevent complications, and provide supportive care. Vaccination is the best way to prevent the infection (pre-exposure prophylaxis), and it’s particularly recommended for those at high risk, especially during outbreaks.
In August 2024, the World Health Organization (WHO) declared the mpox outbreak a public health emergency of international concern, underscoring the importance of continued vigilance and prevention efforts.

At least 60 people have died, and over 1,000 have fallen ill in Congo’s Équateur Province due to a mysterious illness, according to the latest WHO report issued on February 27. The illness is marked by symptoms such as fever, headache, chills, sweating, stiff neck, muscle and joint pain, body aches, runny or bleeding nose, cough, vomiting, and diarrhea.

At a news conference in London on February 28, Dr. Michael Ryan, WHO’s director of emergencies, suggested that the outbreak was more likely caused by poisoning rather than an infectious disease like malaria, which had been speculated by experts at the African Centres for Disease Control and Prevention. He noted that the rapid onset of symptoms and fatalities pointed to a toxic event, possibly linked to a biological cause such as meningitis or chemical exposure, with a “very strong level of suspicion” directed at a contaminated water source. More information on the situation is awaited.

As per the National Institute of Neurological Disorders and Stroke, Guillain-Barré syndrome (GBS) is a rare neurological disorder in which the immune system mistakenly attacks the peripheral nervous system—the network of nerves that transmits signals between the brain, spinal cord, and the rest of the body. The condition can progress rapidly, leading to muscle weakness or, in severe cases, paralysis that may require assisted breathing.
Symptoms vary in intensity, with some individuals experiencing only mild weakness while others face significant impairment. Additional symptoms can include difficulty with eye movement and vision, trouble swallowing, speaking, or chewing, tingling sensations in the hands and feet, severe pain (especially at night), coordination issues, abnormal heart rate or blood pressure, and digestive or bladder control problems. While the disease is rare, as per the CDC, each year, an estimated 3,000 to 6,000 people develop GBS in the US.

Since early January, Pune(India) has reported 160 cases of Guillain-Barré Syndrome (GBS), with five suspected deaths. Currently, 48 patients are in intensive care, 21 are on ventilators, and 38 have been discharged, according to official figures. As per the BBC, the outbreak is linked to Campylobacter jejuni, a common foodborne pathogen and a leading global cause of GBS. Similar outbreaks have been reported worldwide, including Peru, which saw over 200 suspected cases and at least four deaths in early 2023, prompting a national health emergency. Two-thirds of those cases were also linked to Campylobacter jejuni.