under the microscope
under the microscope
By Priya Dhagat , MS , MLS ( ASCP ) CM , CIC
Coxsackievirus Conundrum : Common in Children , Complex in Adults
We are all too familiar with the numerous of viruses circulating during the fall season – SARS-CoV-2 , influenza , RSV , rhinoviruses , and many more . Alongside those viruses is also coxsackievirus which is a common pathogen known to cause hand-foot-and-mouth disease ( HFMD ). In the Unites States , most cases occur in the summer and though the fall season . In fact , just last month Duke University reported a large unprecedented outbreak of HFMD , with more than 60 cases within four weeks . In Massachusetts , Holyoke Public Schools reported an outbreak of 14 cases .
Coxsackieviruses are nonenveloped RNA viruses belonging to the enterovirus genus of the Picornaviridae family . Coxsackieviruses are divided into two groups based on their pathogenicity : Group A and Group B . Group A coxsackieviruses primarily infect the skin and mucous membranes , leading to variety of signs and symptoms including painful red blisters in the throat and on the tongue , gums , inside of the cheeks , the palms of hands , and soles of the feet . Group B coxsackieviruses tend to infect the heart , pleura , pancreas , and liver , causing myocarditis , pericarditis , and hepatitis . At least 23 serotypes of Group A and 6 serotypes of Group B are recognized . Coxsackievirus A16 is the most common cause of HFMD in the United States . Other coxsackievirus serotypes can also cause HFMD , such as coxsackievirus A6 .
Transmission occurs by direct contact with saliva , respiratory secretions , vesicle fluid , or stool of an infected person as well as by direct contact with contaminated surfaces and objects , such as shared toys or eating utensils .
Viral replication occurs in the upper respiratory tract ( primarily in the tonsils ) and the gastrointestinal tract . Based on the serotype and corresponding tissue-specific tropism , infection may spread to the central nervous system , skeletal muscles , myocardium , skin , and liver , leading to viremia and development of symptoms after an incubation period of about three to six days . Initial symptoms begin with fever , malaise , sore throat and may lead to the eruption of the characteristic painful vesicles in the mouth and on the hands and feet . The viral load is high between three and seven days of infection . Illness is usually self-limited with recovery within seven to ten days .
According to the Centers for Disease Control and Prevention ( CDC ), people with HFMD are most contagious during the first week that they are sick and can sometimes spread the virus to others for days or weeks even after symptoms go away . Coxsackieviruses can be detected in the stool for about six weeks after infection and from the oropharynx for about four weeks after infection . Since coxsackieviruses are non-enveloped viruses , they are more resistant to environmental stressors such as desiccation and temperature or humidity changes and may stay viable on hard and nonporous surfaces for up to two weeks in favorable conditions .
HFMD is more common in children , especially in daycare and elementary school settings , compared to adults who likely have cross-immunity from other common enteroviruses or immunologic memory from childhood infections . Although HFMD in adults is rare , incidence has been increasing in recent years with adult patients presenting with atypical clinical presentations : high fever , varied distribution of lesions , marked skin involvement , and a longer course of the disease . Considering fever with rash is a common symptom combination for a variety of infections ( such as chickenpox , mpox , rickettsiosis , and syphilis as described in this article ) as well as non-infectious causes , understanding clinical history and epidemiological context must be assessed especially in adult patients .
Diagnosis for HFMD is usually clinical , but unfamiliarity with the disease presentation or clinical variability can lead to difficulties in diagnosis . For instance , in May 2022 an outbreak of a febrile rash with red blisters , joint pain and swelling , vomiting and diarrhea in over 100 young children in India was dubbed the “ Tomato Flu ”, making headlines as a potential new virus . Turns out , it was likely Coxsackievirus A16 based on viral sequencing results . Reverse transcription PCR ( RT-PCR ) assays may be used as confirmatory testing for atypical or severe cases using vesicle fluid , throat swabs , or stool specimens .
Just like the respiratory viruses we are all too familiar with , infection prevention for coxsackieviruses is no different . Hand washing , avoiding touching eyes and mouth , and cleaning and disinfecting commonly touched surfaces in environments where transmission may occur is are vital . In healthcare settings , standard precautions should be followed and contact precautions for diapered or incontinent children for duration of illness and to control institutional outbreaks .
Click here to read about atypical clinical presentations of HFMD in three adults caused by Coxsackievirus B .
Click here to read more about the 2022 outbreak in children in India , which highlights the clinical variably of the disease .
Priya Dhagat , MS , MLS ( ASCP ) CM , CIC , is an infection preventionist and the associate director of the system-wide Special Pathogens Program within the Department of Emergency Management at New York City Health + Hospitals , overseeing special pathogen preparedness and response efforts across New York City Health + Hospitals frontline healthcare facilities . Additionally , she supports and offers subject matter expertise for infection prevention topics for the National Emerging Special Pathogens Training and Education Center ( NETEC ).
8 november 2023 • www . healthcarehygienemagazine . com