Quarantine to Cohorting: The Evolving Toolkits of Biosecurity

INTRODUCTION

An unprecedented situation arose during the COVID-19 pandemic. The administration advised measures such as hand hygiene, social distancing, announcing the closure of schools, banning international travel, and establishing containment zones and quarantine centers. There was growing public disbelief about the effectiveness of quarantine policies.¹ These scenes unfolded in every country during the COVID-19 pandemic of 2019–2022. Quarantine, a term probably forgotten for years—resurfaced in public memory.

Scientifically, quarantine is defined as restricting the movement and separating organisms that may be exposed to a contagious disease to escape the period of infectivity.² Organisms include humans, plants, and animals. Quarantine is sometimes imposed for individuals exposed to an infectious agent who do not have treatment for the disease or who do not accept the compulsory treatment protocol.³ The recent history of worldwide transmission of new pathogens such as Severe Acute Respiratory Syndrome (SARS), Avian Influenza, Ebola, and most recently, COVID-19 has proven that humans are still struggling against pathogens, making quarantine an important public health tool.⁴ The lack of specific vaccines and drugs against COVID-19 increased the need for general ancient preventive measures like quarantine. Effective quarantine was supported by good public awareness and ground-level health surveillance.⁵ Another term, “isolation,” also came into the picture during COVID-19, is applied to those already known to be infected.⁶ Both quarantine and isolation are two parts of the broader toolkits of biosecurity.²

Quarantine has been used in various fields of animal and environmental sciences, such as human health, agriculture, veterinary sciences, forestry, and biodiversity conservation.⁶ It serves as an effective method of preventing both zoonosis and reverse zoonosis. With the evolving concept of “One Health”, plant and animal health are considered equally important to human health. Several countries, including India, have guidelines for plant quarantine to inspect imported agricultural products and prevent the entry of exotic plant species and pests into the country.⁷ Animal quarantine to prevent the spread of rabies remains active in several countries, such as New Zealand and Ireland. The United Kingdom had enforced strict universal quarantine regulations from 1897 to 2012 to prevent the reimportation of rabies, which has an internationally recognized incubation period requiring a quarantine length of 6 months.¹

HISTORY OF QUARANTINE

The word “quarantine” was first mentioned in the Oxford English Dictionary in 1663. The term traces its roots in the Italian word “quarantena” (quarantine of ships), which was derived from the Italian word “Quaranta” (forty), originated from the Latin word “quadraginta.”⁸ In the 14^th century, the spread of the Bubonic plague, also known as the Black Death, with a high case fatality rate, wiped out one-third of the European population, and began the practice of mass isolation.⁹ It was believed that any disease exposure would manifest clinically within 40 days and any symptoms appearing after that period were unlikely to be acute or dangerous.⁸ Venice became the first port in Europe with a documented quarantine practice in 1374, requiring all sailors quarantine practice to stay in quarantine on their ships for 40 days. “Lazaretto” or quarantine stations later established started on islands in Venice in 1403, where all sea arrivals were quarantined. “Lazaretto” is an Italian word depicting a place of confinement for persons with leprosy, meaning “Lepers’ House.” This concept of quarantine later spread to other countries in Western Europe.¹⁰ In the early 17^th century, the incidence of plague decreased, but other diseases such as cholera and yellow fever began to spread. Quarantine laws were gradually extended to address these emerging threats.¹¹ These diseases gradually spread from Western Europe to the new settlements in North America, i.e., the United States.

The utility and scientific basis of quarantine were questioned in parts of Europe and America, as there were no clear and shared definitions regarding the length of quarantine. At times, quarantine was enforced as a repressive measure with a political motive, especially in the colonies of America.¹² In 1710, the Quarantine Act was passed in England, which included a provision for the death penalty for individuals who violated the quarantine norm of 40 days for humans and goods that were suspected or known to have contact with plague. From the public health perspective, the dilemma was the lack of uniformity in quarantine policies across countries.¹¹ In 1834, France proposed an inter-nation meeting to develop globally standardized quarantine norms. However, the First International Sanitary Conference was not held until 1851, in Paris.¹³

Yellow fever peaked in the second half of the 19^th century, prompting the US government to pass a federal quarantine legislation in 1878. In 1893, an agreement was established between the United States and Europe regarding the international reporting of diseases.

It marked an important turning point in the standardization of quarantine measures. Till the discovery of streptomycin in 1947, diseases like tuberculosis (TB) led to both direct and indirect quarantine on a large scale.⁶

In 1907, twenty countries joined to establish an International Office of Public Health. The office issued quarantine rules for different types of travelers in 1928. The organization was later replaced by the World Health Organization (WHO), which changed the terminology of “quarantining diseases” to “diseases under international health laws” and “diseases under surveillance”.¹² With the development of molecular biology and immunology in the 20^th century, there was a race to develop vaccines and antibiotics against transmissible diseases. This led to a decline in the importance of quarantine as a method of disease control. Several quarantine centers around the globe were gradually closed.⁸ The necessity of quarantine again resurged during SARS in 2003, avian flu of 2008, Ebola of 2014, and gained major importance during the COVID-19 pandemic. These emerging diseases led to the restoration of quarantine centers and the establishment of new centers in countries that had never previously experienced the “Black Death.”

FRAMING OF QUARANTINE IN MODERN PUBLIC HEALTH

The WHO adopted the International Health Regulations (IHR) in 1969, initially covering only six diseases. Major revisions in IHR were made by the World Health Assembly in 1993, prompted by increased international travel resulting from improved connectivity and greater human mobility for various purposes.

The most recent revision in IHR was done in 2005 and came into effect in 2007.¹⁴ The IHR also defines the criteria for determining whether a specific event qualifies as a “public health emergency of international concern.” It monitors international health threats, reports them in a timely manner, prepares for and responds to disease outbreaks and health emergencies, and facilitates cooperation among countries for disease surveillance.¹⁵ The recent revisions address contemporary concerns regarding health measures related to quarantine and isolation, ensuring they are implemented within an appropriate guideline.⁵ In the United States, the Centers for Disease Control and Prevention (CDC), previously known as the National Communicable Disease Center, was established in the 1960s, developed quarantine guidelines periodically, and was equipped with several quarantine centers.⁵

QUARANTINE: AN ETHICAL DILEMMA

When the anticipated benefits to society, such as preventing or limiting infectious diseases, outweigh the expected costs, including moral considerations, quarantine and isolation can be considered justified and ethically necessary. A comparison of the ethical aspects of quarantine and isolation reveals that quarantine presents greater ethical challenges in two ways. First, individuals who may not be infected are nonetheless confined as part of the process. Second, quarantine can lead to situations where uninfected individuals, who have not been in contact with the infectious person, are forced to remain in proximity to those who are infected, thereby increasing their risk of contracting the disease.¹⁵

When soldiers or the police are deployed to ensure citizens’ compliance, quarantine becomes mandatory. Compulsion is commonly used in public health when public health concerns pose a security risk to a nation.¹⁶ It is important to consider the anticipated health, security, and economic benefits of quarantine and vaccination compared to any potential drawbacks, as well as any ethical implications of enforcement. It is ethically acceptable to enforce quarantine as a public health measure, even if it involves some level of compulsion. This is especially true when the overall expected benefits of mandatory public health measures outweigh those of alternative approaches.¹⁵ The duty of easy rescue states that there is a moral obligation to give up something if the importance of this sacrifice is minor compared to the significance of the good that will be achieved, rather than when the cost is low in absolute terms.¹⁷ Therefore, mandatory public health actions such as quarantine are morally justified. The use of compulsion in public health must meet three conditions: (1) Compulsory public health measures should aim to prevent or contain significant harm; (2) More lenient measures to prevent or contain infectious diseases should be preferred over more restrictive ones; and (3) The public health measure imposed should be proportionate to the threat to public health.¹⁵

The personal impact of quarantine and isolation can be significant even when its moral weight is minimal. The loss and suffering—such as stigmatization and loss of livelihoods are considerably greater than the moral importance of the harm prevented.¹⁵ During the Ebola epidemic, the WHO, in partnership with the Ministry of Health in Liberia, a country in West Africa, found that many quarantined families did not receive food supplies. They also found that communication between quarantined individuals and their families was impossible. This highlights that while the personal impact was substantial, there was also a significant moral cost associated with preventing the disease from spreading.¹⁷

The history of quarantine includes the stigmatization of individuals, families, or entire communities. Notable examples involve the Jewish population in Venice during the bubonic plague, Mexicans during the swine flu of 2007, and the Chinese during the SARS and COVID-19 outbreaks.¹ The impacts of quarantine have been studied extensively during the SARS and COVID-19 outbreaks. Social isolation can contribute to negative mental issues such as anxiety and stress. During crises like pandemics, when people need greater physical and emotional support, quarantine removes one of our coping mechanisms.¹⁸ Utilizing electronic media or the telephone for social interaction, engaging in enjoyable activities, and accessing essential, accurate, and timely information are all crucial in reducing anxiety and depression.¹ Like other health interventions, quarantine has its implementation limitations. Both scientific and general communities must remain aware of these constraints at institutional and societal levels. The legal and ethical boundaries of quarantine became increasingly apparent in the 1980s with the emergence of Acquired Immuno-Deficiency Syndrome (AIDS).¹⁹

COHORTING: THE EVOLVING BIOSECURITY TOOL

In the 21^st century, the world has witnessed the persistent emergence and re-emergence of various diseases. Many newly arising infectious diseases, such as Monkeypox and Nipah, spread through person-to-person transmission.^20,21 There has also been a rise in healthcare-associated infections in recent times. Although the overall number of hospital admissions remains low, approximately half of the patients admitted to Intensive Care Units (ICUs) are infected with nosocomial organisms.²² The number of organisms resistant to multiple antimicrobials, known as Multi Drug-Resistant Organisms (MDROs), is increasing and causing severe nosocomial and community-acquired infections. The misuse of antibiotics is rising, particularly in developing countries, and inappropriate clinical practice are contributing to an increased risk of disease spread. This has led to the emergence of new outbreaks caused by MDROs, for which there are no effective treatments or preventive strategies—thereby elevating the threat to public health.²³ These infections significantly increase medical costs, mortality and morbidity, and poorer patient outcomes.²⁴

Infection can be transmitted to other patients or the environment through direct and indirect contact. Direct contact refers to the transfer of pathogens from one infected person to another without involving a contaminated intermediate object or person (e.g. from the caregiver to the patient or vice versa). Indirect transmission involves the spread of pathogens via a contaminated object or person.²⁵ Instances of hospital-acquired infections being transferred from staff to patients, such as outbreaks of Pseudomonas aeruginosa among neonates, have been reported.²⁶ Overcrowding and patient proximity are driven by the extensive movement of patients, attendants, and staff between wards, operation theatres, and intensive care units (ICUs). The risk of direct transmission of infection increases with the high number of patients in each ward.²⁷ Strong evidence of patient-to-patient transmission of infection has been demonstrated through microbiological and genotypic analysis of various causative pathogens associated with outbreaks.¹⁰ The transmission risk can be minimized using tools of biological protection, such as isolation and cohorting. The newer method of cohorting has been cited in various literature, although no national or global organization has officially endorsed it.²⁸

Cohorting refers to as the grouping of patients as a precautionary measure. The term “cohort” is used in epidemiology to mean “a group of people who share a common feature or aspect of behavior.”²⁹ The US federal government-run CDC has emphasized providing additional attention to ICU patients infected with MDROs through various preventive measures.³⁰ Cohorting involves both patients and healthcare staff and has been successfully implemented during outbreaks of Methicillin-Resistant Staphylococcus aureus (MRSA), and Vancomycin-Resistant Enterococci (VRE) in the Western world.¹⁰ In cohorting, all infected patients are admitted to a single dedicated hospital ward or ICU.³¹ Cohorting patients in a single unit has proven effective in controlling disease spread in various situations, such as managing an outbreak of neonatal ICU-acquired infection caused by Acinetobacter, creating a distinct hospital ward to manage the VRE outbreak, and assigning dedicated nursing staff to a single unit for patients affected by carbapenem-resistant Klebsiella pneumoniae.^27-29 If a private ward or ICU is unavailable, it is feasible to designate a separate zone within the unit or ICU for cohorting. This approach has been proven effective in various settings.¹⁰ Assigning a dedicated team of healthcare professionals to these units or cohort zones for cohorting can help limit transmission to non-infected patients.²⁸

Healthcare facilities can employ various sustainable methods to control the increasing number of infections due to MDROs, such as assigning dedicated staff to infectious disease units, promoting the use of disposable equipment whenever feasible, and conducting regular screenings of all personnel.¹⁰ Cohorting may prove as one of the effective modes of achieving infection control, especially in the case of emerging concerns of MDROs. The last guidelines of the CDC regarding the management of MDRO infection were back in 2006. The guidelines include implementing changes to the system to ensure timely and effective communication, ensuring the proper number and placement of hand washing sinks and dispensers for alcohol-based hand rubs; adjusting staff deployment to match the required level of care; and ensuring that recommended infection control practices are followed.²³

ISSUES IN IMPLEMENTATION OF COHORTING

Neither isolation nor cohorting is feasible in the Indian setting due to the structural design of wards and ICUs. This limits the use of such disease prevention strategies as recommended in the literature.³² In low and middle-income countries where hospital infrastructure is inadequate and ICU availability is limited, the implementing cohorting remains a significant challenge.³¹

Standard isolation and quarantine guidelines are published periodically by health agencies and the government, depending on the disease in question. India recently introduced the guidelines for ICU admission and discharge; however, no guidelines exist for establishing distinct isolated ICUs for infected or suspected cases to control outbreaks or prevent the spread of infections, especially MDROs.³³ Cohorting patients based solely on suspicion is also considered medically unethical, similar to quarantine practices. Therefore, cohorting of patients and staff for infectious diseases should only occur after microbiological confirmation or positive culture results.

FUTURE OF COHORTING IN INDIA

Cohorting of MDRO-infected patients is not limited to hospital settings for controlling disease spread, but it can also be applied in the community settings for diseases like TB, where preventing further transmission is essential. TB remains a significant public health concern in India. The health system has launched various programs over the years, beginning from independence. A major current challenge is the increasing prevalence of Multi Drug Resistant TB (MDR-TB). Several studies have attempted to analyse the effectiveness of isolation and quarantine practices in TB.^34,35 We propose implementing cohorting strategies at the community level to prevent the mode of spread and reservoir (MSR) of multidrug-resistant and Extremely Drug Resistant TB (XDR-TB). The infected person can be placed in a private room in a public health facility. In a country like India, it is often impractical to allocate private rooms to every patient. Therefore, patients with similar drug resistance patterns may be cohorted in the same room. Cohorting should not apply to patients dependent on healthcare providers or family members for medical care and daily living activities. Any healthcare personnel caring for patients undergoing treatment for MDR-TB should be thoroughly trained in hand hygiene and the proper use of personal protective equipment (PPE). Such facilities may be designated as “Long-term care Facility for TB.”

CONCLUSION

Quarantine, initially used to control the spread of TB in the early 20th century, showed positive outcomes in various countries. Public health experts and epidemiologists have continued to explore the reintroduction of quarantine as a public health measure to control TB. Similarly, cohorting may serve as an alternative public health strategy to help eliminate TB. Cohorting, along with the concept of “Long-term Care Facility for TB,” could be an effective public health tool to limit the spread of infection—potentially as successful as quarantine was in breaking the chain of infectious diseases during the 14^th to 15^th centuries.