The Outbreak Brief

Deep in the tropical forests of Central and South America and parts of the Caribbean, a mosquito can deliver more than just an irritating bite. Mayaro virus is a relatively overlooked mosquito-borne infection that can begin with fever, headache, rash, and intense muscle and joint pain. For some people, however, the illness does not simply disappear when the fever breaks. Joint pain can persist for weeks or even months, turning a seemingly short infection into a prolonged struggle. Because Mayaro can resemble other mosquito-borne diseases, including dengue and chikungunya, recognizing travel and mosquito exposure history and using appropriate laboratory testing are important for diagnosis. There is currently no widely available vaccine or specific antiviral treatment, making prevention the strongest defense. In this episode of Outbreak Brief, we enter the forests where Mayaro circulates, explore how the virus moves from mosquitoes to humans, and examine why this lesser-known infection deserves greater attention as mosquito-borne diseases continue to expand their reach.

What if a puddle, a muddy field, or floodwater could carry a bacterium capable of causing life-threatening disease? Leptospirosis is a global zoonotic infection caused by Leptospira bacteria, often entering the human body through broken skin or mucous membranes after contact with water or soil contaminated by infected animal urine. For many people, it begins like an ordinary flu, with fever, headache, chills, and severe muscle aches. But in some cases, the infection takes a dangerous turn, damaging the kidneys and liver and causing Weil’s disease, or even triggering severe pulmonary hemorrhage. From agricultural workers and military personnel to people exposed to floods and tropical environments, those who encounter contaminated water or soil can face increased risk. The good news is that leptospirosis can be treated, and recognizing the infection early is critical. In this episode of Outbreak Brief, we uncover how this stealthy bacterium moves from animals and the environment into humans, why severe disease can develop so quickly, and how exposure prevention, protective equipment, and timely antibiotic treatment can help stop a potentially deadly infection.

For years, stomach ulcers were blamed on stress, spicy food, or an overly acidic diet. But deep inside the stomach, another culprit was quietly at work. Helicobacter pylori, or H. pylori, is a bacterium capable of surviving in the harsh acidic environment of the stomach, where it can establish a persistent infection and trigger chronic inflammation. Many people carry it without ever knowing, yet in others, the infection can damage the stomach lining, leading to peptic ulcers and increasing the long-term risk of gastric cancer. Today, H. pylori can be detected through breath, stool, blood, or endoscopic testing, and eradication requires carefully selected antibiotic combinations along with acid-suppressing medications. But this is more than a story about ulcers. It is a story about a remarkably adapted microorganism, a hidden infection affecting millions, and a bacterium that changed what medicine understands about the human stomach.

In this episode of Outbreak Brief, we step into the warm, damp environments where tinea pedis, better known as athlete’s foot, thrives. Caused primarily by dermatophyte fungi, this remarkably common infection can spread through direct contact and contaminated surfaces in places such as locker rooms, swimming pools, and shared showers. What may begin as mild itching, scaling, or peeling skin can become persistent and, in vulnerable individuals, lead to secondary bacterial infections and cellulitis. We explore how athlete’s foot develops, why certain people are more susceptible, how clinicians diagnose and treat the infection, and why simple measures such as keeping feet dry, wearing breathable footwear, and practicing good hygiene can make a significant difference. On Outbreak Brief, we uncover the science behind an everyday infection and why preventing its return can be just as important as treating it.

In this episode of Outbreak Brief, we explore anaplasmosis, a potentially serious tick-borne disease caused by the bacterium Anaplasma phagocytophilum. Primarily transmitted by infected blacklegged ticks, the disease is most common in the Northeast and Upper Midwest of the United States and often begins with symptoms that resemble the flu, including fever, chills, headache, and muscle aches. While many patients recover with prompt treatment, delayed diagnosis can allow the infection to progress to severe complications, including organ failure and, in rare cases, death. We examine how anaplasmosis spreads, why early recognition is so important, and why doxycycline remains the treatment of choice when the disease is suspected. We also explore practical strategies for preventing tick bites and protecting yourself after spending time outdoors.

In this episode of Outbreak Brief, we explore mumps, a highly contagious viral infection best known for causing painful swelling of the salivary glands—but capable of affecting far more than the face and jaw. Spread primarily through respiratory droplets and saliva, the virus can move quickly through households, schools, universities, and other close-contact communities, with symptoms often appearing weeks after exposure. Although most people recover without lasting problems, mumps can occasionally lead to serious complications, including meningitis, hearing loss, and inflammation of the reproductive organs. We examine how the virus spreads, how clinicians confirm infection, why isolation and public health surveillance remain important during outbreaks, and how the MMR vaccine has dramatically reduced the global burden of this once-common disease. Join Outbreak Brief as we uncover the science behind mumps and the continuing challenge of controlling outbreaks in highly connected communities.

In this episode of Outbreak Brief, we explore rubella, also known as German measles, a highly contagious viral infection that is often mild in children and adults but can become devastating when it occurs during pregnancy. Although infection may cause only a low-grade fever, rash, and swollen lymph nodes, exposure during early pregnancy can result in congenital rubella syndrome (CRS), causing permanent complications such as hearing loss, congenital heart defects, vision problems, and neurological impairment. We examine how rubella spreads, how laboratory testing confirms infection and immunity, and why vaccination remains the most powerful tool for prevention. Beyond the individual patient, rubella highlights the importance of maintaining high immunization coverage and protecting pregnant individuals and their unborn children through effective public health surveillance and global vaccination programs.

In this episode of Outbreak Brief, we uncover the hidden world of hookworm—a neglected tropical disease caused primarily by Ancylostoma duodenale and Necator americanus. The infection begins in an unexpected place: contaminated soil, where microscopic larvae can penetrate bare skin before traveling through the body and eventually reaching the small intestine, where adult worms attach to the intestinal lining and feed on blood. Although many infections produce few noticeable symptoms, chronic infection can lead to iron-deficiency anemia, protein loss, fatigue, and impaired growth and development in children. We explore the remarkable lifecycle of these parasites, how clinicians diagnose infection through stool testing and molecular methods, and how treatment with antiparasitic medications can eliminate the worms. Most importantly, we examine how sanitation, proper footwear, health education, and global control programs can break the cycle of transmission and protect communities from this persistent tropical disease.

In this episode of Outbreak Brief, we take a closer look at seasonal influenza one of the world's most persistent and underestimated respiratory viruses. Although many people recover within a week, influenza continues to cause millions of severe illnesses and hundreds of thousands of deaths globally each year, placing young children, older adults, pregnant individuals, and those with chronic medical conditions at the greatest risk. We explore how influenza viruses evolve from season to season, why annual vaccination remains our strongest defense, and how antiviral medications can reduce severe outcomes when started early. We also examine the serious complications that can follow influenza infection, including pneumonia and secondary bacterial infections such as MRSA, and discuss the vital role of global surveillance, infection prevention, and public health preparedness in reducing the impact of this recurring viral threat. Join Outbreak Brief as we uncover the science behind the virus that returns every year and why staying one step ahead remains essential.

In this episode of Outbreak Brief, we investigate vancomycin-resistant Enterococcus (VRE), one of the most formidable healthcare-associated pathogens threatening modern medicine. Once considered a relatively harmless intestinal bacterium, Enterococcus has evolved resistance to vancomycin one of the antibiotics traditionally reserved for difficult infections—transforming it into a dangerous superbug capable of causing bloodstream infections, surgical site infections, urinary tract infections, and life-threatening sepsis. VRE poses its greatest threat to critically ill patients, particularly those in intensive care units, individuals with weakened immune systems, and patients requiring invasive medical devices. We explore how antibiotic resistance develops, why VRE spread accelerated during the COVID-19 pandemic in many healthcare settings, the challenges clinicians face in treating multidrug-resistant infections, and the infection prevention strategies that hospitals rely on to stop transmission. Join Outbreak Brief as we uncover the science, clinical impact, and ongoing battle against one of healthcare's most persistent antimicrobial resistance threats.