Do Crew Isolation Policies for AGE Need to Change?

Image of a man holding toilet paper, with the words, Do Crew Isolation Policies for AGE Need to Change.

The isolation of individuals infected with a communicable disease—our previous article “How Murphy’s Law Can Help Prevent Disease Outbreaks” addresses the terminology—is a critical component of illness prevention and control strategies both on board and ashore. The International Health Regulations (2005)define isolation as the “separation of ill or contaminated persons or affected baggage, containers, conveyances, goods or postal parcels from others in such a manner as to prevent the spread of infection or contamination.”

Initially ratified by the World Health Assembly in 1969 and last revised in 2005, the International Health Regulations (IHR) are an apparatus of international law that is legally-binding in 196 countries, including all World Health OrganizationMember States. The IHR establishes requirements for the detection of, and response to, public health risks, and provide a global legal framework for the inspection of maritime vessels and the issuance of ship sanitation certificates.

During the COVID-19 pandemic, maritime guidelines issued by health authorities such as the U.S.Centers for Disease Control and Prevention (CDC) and theEU HEALTHY GATEWAYS Joint Action program, required cruise lines to isolate passengers and crew infected with the SARS-CoV-2 virus in a dedicated isolation ward or single-occupancy cabin. Although the terms “quarantine” and “isolation” were sometimes used interchangeably by the general public during the pandemic, the intent behind separating sick individuals was clear: a person infected with the virus shouldn’t be accommodated with someone who was not.

One might anticipate that a similar approach could be applied to other highly contagious diseases, such as norovirus or influenza (flu). If so, existing cruise line isolation policies may come as a surprise.

What Are the Cruise Industry Guidelines for Isolation?

The CDC’s Vessel Sanitation Program (VSP) 2018 Operations Manual—applicable to all cruise vessels with a foreign itinerary calling U.S. ports and carrying 13 or more passengers—provides a clear definition of isolation:

“The separation of persons who have a specific infectious illness from those who are healthy and the restriction of ill persons’ movement to stop the spread of that illness. For VSP’s purposes, isolation for passengers with AGE symptoms is advised and isolation for crew with AGE symptoms is required.”

VSP 2018 Operations Manual

The Vessel Sanitation Program is designed to assist the cruise industry in “fulfilling its responsibility for developing and implementing comprehensive sanitation programs to minimize the risk for acute gastroenteritis”. Acute gastroenteritis (AGE) covers a wide range of illnesses, including those caused by:

Food employees—crew who directly handle food, food equipment and utensils, linens, or food-contact surfaces—are required by the guidelines to be isolated until 48 hours after symptom resolution; non-food employees (and passengers) should be isolated until symptom-free for a minimum of 24 hours. Symptoms of AGE include diarrhea, vomiting, abdominal cramps, headache, muscle aches, and fever.

Based on the U.S. FDA Food Code and the WHO Guide to Ship Sanitation, the VSP Operations Manual has been a significant force in shaping global cruise ship health regulations. Most equivalent regional guidelines have adopted similar definitions and policies for the isolation of AGE-symptomatic passengers and crew.

How Cruise Lines Isolate Sick Crew

Numerous cruise lines do not routinely isolate crew infected with an acute gastroenteritis illness in a single-occupancy cabin. Unlike Senior Officers and the majority of Junior Officers, who have private living quarters, most crew members are assigned to shared cabins, often residing with at least one other person. The majority of crew accommodation is found below the vessel’s water line, on the lowest decks of the ship, with many crew also sharing bathroom facilities with the occupants of an adjoining cabin.

While disease surveillance requirements for cabinmates and close contacts of symptomatic individuals are in place to mitigate the spread of communicable diseases on board, consider an example of a crew member infected with AGE. The predominant symptoms of acute gastroenteritis are typically diarrhea, vomiting and stomach cramps. As one can imagine, sharing a cabin and bathroom facilities with a person evacuating the contents of their stomach through the body’s two main “exit offices” is an uncomfortable situation for all concerned.

Norovirus is a highly contagious disease capable of rapid propagation in a closed environment like a cruise ship. Its primary mode of transmission is the fecal-oral pathway, spreading directly from person-to-person through direct contact or via indirect transference routes: inanimate objects such as doorknobs and elevator buttons soiled through improper hand washing practices, or the consumption of contaminated food or water.

During an AGE outbreak, several modes of transmission usually occur almost simultaneously, making the cause of an outbreak difficult to determine. For instance, initial food-borne transmission is often followed by secondary person-to-person transmission. Sick individuals can shed billions of viral particles in their stool and vomit, with virus shedding typically beginning with the onset of symptoms. It is estimated that as few as 10-100 viral particles may be sufficient to infect an individual: comparable quantities are also projected for viruses like SARS-CoV-2 and influenza.

Are AGE Outbreaks Common on Cruise Ships?

Real-time information on cruise ship gastroenteritis outbreaks is not readily available to the public. With the exception of those taking place on cruise vessels sailing in U.S. waters—as published on the VSP’s website—most outbreaks only become common knowledge when they receive media coverage. VSP generally post cruise ship outbreak information when all the following criteria is fulfilled:

  • On ships under VSP jurisdiction.
  • On ships carrying 100 or more passengers.
  • On voyages from 3-21 days long.
  • On voyages where 3% or more of passengers or crew report symptoms of gastrointestinal illness to the ship’s medical staff.

Norovirus is the leading cause of gastroenteritis outbreaks on board. At the time of this writing, 17 AGE outbreaks have been documented on cruise vessels overseen by the VSP since the onset of 2023, with norovirus identified as the responsible pathogen in 16 instances, accounting for 94% of all outbreaks. Over the period extending from 2010 to 2023, norovirus was the causative agent in 113 (79.5%) of the 142 reported outbreaks.

There are an estimated 300-plus ocean-worthy cruise vessels currently in operation worldwide, with approximately 36 million passengers anticipated to embark on a vacation at sea this year. While the United States is a major destination for cruise lines, cruise ships operate worldwide. In addition, it is a well-known industry secret that public health standards on cruise ships are generally higher when sailing in U.S. waters. This is largely attributed to the unannounced inspections conducted by VSP officers to verify ships are operating and maintaining appropriate standards in accordance with the VSP Operations Manual guidelines.

Consequently, obtaining an accurate understanding of the frequency and prevalence of AGE outbreaks on cruise ships is challenging. Norovirus alone is responsible for an estimated 685 million gastroenteritis cases worldwide each year, about 20% of all diarrhea cases. It is certainly not a cruise ship “problem,” as media reports often convey; however, individual cases of acute gastroenteritis illness occur as frequently on board as they do ashore.

Are Changes to Crew Isolation Policies Feasible?

When it comes to accommodation options, cruise ships are no different than any other land-based holiday destination: there are a finite number of cabins or staterooms available. Over the years, shifts in global maritime regulations and consumer demand have influenced cabin availability, particularly on older, smaller cruise ships. Revised standards for nautical and engineering watchkeeping, along with improved entertainment offerings, have necessitated the reassignment of crew members to staterooms previously designated for passengers.

Such changes have consequences for revenue, and financial sustainability is unquestionably the primary indicator of success in business. Success is not solely determined by financial gain: guest satisfaction, environmental sustainability, and crew turnover rates are equally important critical Key Performance Indicators (KPIs) for cruise lines. However, without profitability, the lifespan of any business is limited.

Cruise line isolation policies for AGE are very much an outliner. Almost all other communicable diseases—such as varicella (chickenpox) or measles—treated by on board medical staff, result in the strict isolation of the crew member infected. In comparison with the aforementioned diseases, AGE-induced cases usually present with mild symptoms and tend to resolve on their own within a few days. However, the definition of, and reason for, isolation is not exclusively dependent on the severity of symptoms.

The absence of clear regulatory requirements is likely a contributing factor in the difference of approach. In respect of public health, maritime guidelines often rely on vague terminology such as “adequate health measures.” Additionally, the prevalence of “guidelines” as opposed to enforceable regulations presents a further complication.

World Health Day, observed annually on April 7th, serves as a call to action to protect health as a basic human right and to advocate for reforms that support this mission. The theme for World Health Day 2024 is My Health, My Right. Providing crew with the means to recover with dignity and not be unduly exposed to disease-causing pathogens is an essential human right in contemporary society.

Accepting there will always be certain accommodation limitations on a cruise ship, especially during widespread outbreaks, should not impede change. A collective response to the COVID-19 pandemic has clearly demonstrated that with the right determination—where there’s a will, there’s a way—obstacles can be overcome.

To ensure a level playing field across the cruise industry, improvement in individual cruise line AGE isolation policies needs to stem from changes in maritime health regulations. As Socrates, the Greek philosopher and founder of Western philosophy, remarked, “The secret of change is to focus all of your energy, not on fighting the old, but on building the new.” Perhaps on the next occasion when the International Health Regulations or the VSP Operation Manual guidelines are revised, clearer requirements for the isolation of crew on board maritime vessels might be considered.