Non-polio Enteroviruses (NPEV's) - of which there are literally dozens - typically spread in the summer and early fall, and generally produce mild or asymptomatic infections, mostly in children under the age of 10.
Symptomatic cases can range from a mild fever or a runny nose - to HFMD (Hand Foot Mouth Disease) - a generally mild childhood disease characterized by blisters on the hand, feet, and mouth.
In North America HFMD is usually caused by the Coxsackie A16 virus, or less commonly, the Coxsackie A10 virus. In recent years, we’ve also seen the emergence of the Coxsackie A6 virus (see MMWR: Coxsackievirus A6 Notes From The Field) which has been associated with more severe illness.
But for several decades - particularly in Asian and Western Pacific nations - we've monitored yearly NPEV epidemics of a much more serious nature, with the most severe illness linked to Human Enterovirus 71 (EV-71).
Earlier this year we saw an unusual European outbreak of EV-71 (see ECDC Rapid Risk Assessment Of EV-71 Outbreak In Spain), and two years ago the United States was hit by a rare outbreak of EV-D68, which resulted in scores of serious neurological complications in children.
All of which makes enterovirus outbreaks increasingly on our radar.
Today Taiwan's CDC is reporting a sharp rise in enterovirus activity, exceeding the epidemic threshold for the second week in a row.
First their announcement, then I'll return with a bit more.
As enterovirus activity continues to increase, public urged to practice frequent hand washing with soap and water and watch for prodromal signs of complications of enterovirus infection in children( 2016-11-01 )
The Taiwan Centers for Disease Control (Taiwan CDC) announced that enterovirus activity in Taiwan has recently continued to increase. Since the beginning of this semester, enterovirus activity has been higher than the epidemic threshold for two consecutive weeks. Nevertheless, not many new severe cases have been reported. According to the surveillance data compiled by Taiwan CDC, during October 23 and 29, 2016, the number of visits to outpatient services and ER for enterovirus infection in the nation was 13,143, which is 18.3% up from that reported during the previous week (11,109). Currently, coxsackie A virus is the dominant strain circulating in the community. Thus far this year, as of October 31, 151 sporadic cases of EV71 infection, including 129 mild cases, 1 suspected severe case, and 21 severe cases, have been confirmed.
The new severe case of enterovirus infection confirmed last week in a 6-year-old child who resides in northern Taiwan was caused by CA 4. Beginning October 8, the case subsequently developed symptoms, including fever, herpangina, muscle twitching, and leg weakness. The case was hospitalized and reported to the health authority by the hospital. Due to timely diagnosis and treatment, as of now, the case has recovered and been discharged from the hospital. So far this year, a cumulative total of 26 severe cases of enterovirus infection, including 21 caused by EV 71, 2 caused by CA 4 and 1 caused by CA 5, 1 caused by CA 6, and 1 caused by CB 3, and 1 died.
According to the epidemiological investigation, several students attending the same kindergarten with the case have recently become infected with enterovirus and classes have been suspended. Therefore, it might be possible that the case had become infected at the kindergarten. In addition, the case’s brother who resides in the same household had also sought medical attention after developing herpangina and was diagnosed with enterovirus infection. The other family members have not developed enterovirus symptoms. Taiwan CDC once again reminds that enterovirus is highly contagious, especially in crowded places such as households and child care facilities. Childcare facilities are urged to clean and disinfect the environment and toys and objects children play with regularly and educate children the importance of cleanliness in maintaining health in order to prevent disease transmission. Adults who return home from work are advised to change clothes and wash hands with soap and water before coming into contact with children. Additionally, please make sure children wash their hands with soap and water thoroughly when returning home and before having their meals in order to prevent infection.
Taiwan CDC reminds that when a child in a household is diagnosed with enterovirus infection, parents and child caregivers are urged to refrain the sick child from close contact with other children to prevent further spread of the disease and watch for the development of prodromal symptoms of severe enterovirus infection in the sick child such as drowsiness, disturbed consciousness, inactivity, flaccid paralysis, myoclonic jerk, continuous vomiting, tachypnea, and tachycardia to ensure timely treatment. For more information, please visit the Taiwan CDC website at http://www.cdc.gov.tw or call the toll-free Communicable Disease Reporting and Consultation Hotline, 1922 (or 0800-001922).
While rare, one of the most serious complications of enterovirus infection is AFM, or Acute Flaccid Myelitis.
Acute flaccid myelitis (AFM) is a rare illness that affects a person’s nervous system, specifically the spinal cord. AFM may be due to a variety of causes, including viral infection.
AFM is a subset of conditions that fall under a broader `umbrella' of syndromes called Acute Flaccid paralysis (AFP), which may include myelitis, peripheral neuropathy, myopathy, Guillain-Barré syndrome (GBS), toxic neuropathy, and other muscle disorders.
As I wrote last month, the CDC is Investigating an Increase In AFM In The United States, and although the cause it not yet known, enteroviruses are on the suspect list.
We should get an update from the CDC in the next week or so - including AFM case counts for September - on their AFM Surveillance page. When that happens I'll update this blog.