Stopping an outbreak: hantavirus on the MV Hondius

Although an estimated two-thirds of international travelers will develop a travel-related illness, most fevers and respiratory symptoms have self-limiting causes. A notable exception was an outbreak of severe acute respiratory illness that afflicted 13 passengers and crew members (including the ship’s doctor) on the expedition cruise ship MV Hondius and caused three deaths. The first passenger to die most likely acquired the infection from a rodent in Argentina, where the MV Hondius departed on April 1, 2026. Reverse transcriptase polymerase chain reaction (RT-PCR) testing confirmed that the contagious illness was hantavirus cardiopulmonary syndrome caused by the Andes virus, which had previously shown person-to-person transmissibility in crowded social settings.

A 2002 American Family Physician article called hantavirus infection “a zebra worth knowing” because, although it is rare (fewer than 900 cases have been reported in the United States since 2023), prompt diagnosis in persons with early symptoms can be lifesaving. Outside of the Andes virus, hantavirus is acquired by exposure to saliva, urine, or feces of infected rodents, such as the deer mouse in the United States.

After an incubation period of up to several weeks, patients in the prodromal phase of the illness develop fever and myalgias, lasting 3 to 5 days. Characteristic laboratory findings include thrombocytopenia, left-shifted leukocytosis, circulating immunoblasts, and hemoconcentration. The cardiopulmonary phase is heralded by the acute onset of hypotension, pulmonary edema, tachypnea, and progressive hypoxia, usually requiring mechanical ventilation within 24 hours. No specific treatment is available. Despite supportive care, the case fatality rate of hantavirus cardiopulmonary syndrome approaches 40%.

On May 18, 2026, the Centers for Disease Control and Prevention issued a health alert for US clinicians and health departments about when to consider testing patients for hantavirus infection. It is thought that transmission of Andes virus occurs only in the symptomatic phases; therefore, at least 65 US passengers and others with possible Andes virus exposures are being monitored at home by state health departments or in the 20-bed National Quarantine Unit at the University of Nebraska Medical Center, though many of the latter are being forcibly prevented from going home.

Despite a superficial resemblance to the early days of the COVID-19 pandemic—a fatal respiratory illness spread rapidly on a cruise ship while political leaders and public health authorities assert that the risk to the general public is low—Andes virus will not become the next pandemic. (After being cleaned and disinfected, the MV Hondius resumed passenger operations on June 13, 2026.) However, the outbreak response highlighted gaps in global public health preparedness that have widened since the United States withdrew from the World Health Organization (WHO) in early 2026. A fatal outbreak on an oceangoing vessel is an international problem by definition, but efforts by various countries to contain it have been halting and inconsistent. In a JAMA commentary, Dr. Attila Hertelendy and colleagues asserted:

The principal vulnerability exposed by the Hondius outbreak lies not in sustained [viral] transmission, but in delayed recognition, fragmented authority, and inconsistent public health implementation across jurisdictions. … WHO can coordinate information sharing, issue technical guidance, and recommend public health measures, but it cannot compel states to permit disembarkation, harmonize quarantine protocols, or share responsibility for exposed travelers.

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This post first appeared on the AFP Community Blog.

When emotions matter more than evidence: preventing deaths from firearms

In 2019, after another of the horrific mass shooting events that most Americans have become numb to but are far less common in other developed countries, I was asked to participate in a panel presentation on "Gun Violence as a Public Health Issue" at the Family Medicine Education Consortium's annual meeting. I worked hard to make my presentation as non-ideological as possible, mustering slide after slide of statistics showing the rise in firearm-related injuries and deaths since the turn of the century from many peer-reviewed studies. I acknowledged, though, that as with many other public health issues, no number of facts and figures would be completely persuasive. Gun violence is an issue where emotions matter more than evidence. For many, firearm ownership ensures freedom from tyranny, and government restrictions on purchasing guns, however reasonable, represent threats to personal liberty.

The following year, homicides and suicides from firearms surpassed motor vehicle accidents as the leading cause of death in children and adolescents for the first time, and an updated analysis found that the firearm-related death rate in this group increased by 3.9% from 2020 to 2023. For perspective, in 2023, guns killed 4455 children, while Covid-19 infections accounted for 125 children's deaths in 2023 and 547 deaths at the pandemic's peak in 2021. This is why it is as essential for physicians to provide counseling on firearm injury prevention during well-child visits as counseling regarding Covid-19 and other recommended vaccines.

A recent cross-sectional study in JAMA Network Open examined associations between state firearm laws and firearm-related suicides from 1976 to 2024. The investigators focused on 6 types of laws involving handgun permits, waiting periods for firearm purchases, concealed carry licenses, minimum age requirements, extreme risk protection orders, and permits for gun dealers. They found that states that required handgun permits, waiting periods, and/or concealed carry licenses had lower firearm suicide rates, and states with all 3 laws had 25% lower rates than states with none.

Compared to these legislative interventions, individual clinicians have less to offer. The U.S. Preventive Services Task Force found insufficient evidence that screening adults for suicide risk prevents suicides, and it isn't certain that counseling gun owners about safe storage practices (using trigger locks, gun safes, storing ammunition separately) makes a difference, either.

As for gun homicides, public health interventions aimed at resolving conflicts without resorting to violence have shown positive results in Baltimore, Maryland, where gun violence is treated as a contagious disease and "violence interrupters" work diligently to defuse small disputes before they involve firearms. Critically, preventing violence also involves recognizing and addressing its structural causes:

Baltimore’s first comprehensive violence prevention plan takes public safety beyond police, prosecution, and prison by working closely with community groups to focus on prevention and support for those most affected by the violence. ... Community organizations, some partially funded by the Mayor’s Office, connect people to education and life coaching. They help get documents like IDs, birth certificates, and Social Security cards, and they help expunge criminal records, making it easier to get jobs. They pay energy bills and fill gas tanks; they offer emergency relocation, financial stipends, transitional employment support, drug treatment—even helping people to reconnect with their families.

Lancaster Medical Heritage Museum's Object of the Month: Ether Mask

I serve on the Board of Directors of the Lancaster Medical Heritage Museum, and we have inaugurated an "Object of the Month" feature to highlight interesting items from the museum's collections. Here is the one for June.

Before modern anesthesia machines, surgeons relied on devices like this historic ether mask to safely administer anesthetics during surgery.

Used from the late 19th century through the mid-20th century, ether masks allowed physicians to administer ether or chloroform through inhalation by dripping the liquid onto layers of gauze stretched across a metal frame. As the anesthetic evaporated, patients inhaled the vapor, allowing surgeons to perform increasingly complex procedures.

Prior to the development of ether masks, anesthesia was often administered using simple cloth cones or towels soaked in ether, methods that were far less controlled and could cause irritation or burns.

This month’s featured object highlights the evolution of anesthesia and the dramatic changes it brought to medicine and surgery. Ether and chloroform were widely used during the Civil War, World Wars I and II, and the Korean War, transforming battlefield and hospital care alike.

You can see this historic ether mask on display at the museum.

Research provided by Dr. Stephen Olin.