Tuesday, December 12, 2017

Taiwan CDC: Late Season Surge In EV-D68 Cases


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), and over the past couple of years, to EV-D68.
Among the more serious presentations of NPEV infection is Acute flaccid myelitis (AFM) - a rare polio-like illness that affects a person’s nervous system (specifically the spinal cord) - and is characterized by sudden weakness in one or more arms or legs, along with loss of muscle tone and decreased or absent reflexes.
In August of 2014 the United States saw a large increase in AFM cases tentatively linked to EV-D68, a relatively rare non-polio enterovirus that caused a nationwide outbreak of mild to moderate respiratory illness, mostly among children and teenagers (see Kansas City Outbreak Identified As HEV 68).

While a circumstantial case has been made over the past couple of years (see EID Journal Enterovirus D68 Infection in Children with Acute Flaccid Myelitis, Colorado, USA, 2014), no definitive causal link to EV-D68 has been established. Some AFM cases have tested positive for EV-D68, while others have not (cite)
Similar outbreaks have occurred around the world, with PAHO issuing an epidemiological  alert a little over a month ago after a cluster of AFM cases were reported in Argentina concurrent to an outbreak of EV-D68.
Although Taiwan's NPEV season has passed its peak, their CDC today is reporting on an increase in EV-D68 cases - including a couple of serious cases involving limb weakness. 
Parents and child care providers urged to stay vigilant for enterovirus infection as Taiwan CDC confirms 2 new cases of enterovirus D68 infection with severe complications ( 2017-12-12 )

Although the enterovirus epidemic has passed its peak, the number of enterovirus D68 infection cases has continued to increase and the majority of the infected individuals are children aged below 5. Moreover, the primary symptoms of enterovirus D68 infection are fever, runny nose and cough and infected individuals rarely develop typical symptoms of enterovirus infection such as herpangina and hand, foot, and mouth disease. Therefore, the public is urged to remain vigilant of the health of the children and infants in their family and ensure a child receives immediate medical attention if he/she develops symptoms such as acute limb weakness.

Last week, the Taiwan Centers for Disease Control (Taiwan CDC) confirmed 2 new cases of enterovirus D68 infection with severe complications respectively in a 4-year-old boy and a 9-year-old girl who reside in central Taiwan. Both of them developed symptoms, including fever, runny nose, fever, and upper/lower limb weakness on one side of the body in late November. Infection with enterovirus D68 was confirmed in both cases by the Taiwan CDC laboratory. As of now, the cases are still hospitalized for treatment.
 A cumulative total of 15 cases of enterovirus D68 infection have been confirmed in Taiwan thus far this year. Among them, 4 were found to be cases of enterovirus infection with severe complications after case review. In light of the recent increase in the number of cases of enterovirus D68 infection, Taiwan CDC would be convening an expert meeting on December 13 to discuss relevant control strategies and response measures that reinforce surveillance in order to reduce the risk of transmission among children.
Thus far this year, 13 cases of enterovirus infection with severe complications, including 1 death, respectively caused by enterovirus D68 (4 cases), CA 6 (3 cases), CB3 (2 cases), echovirus 5 (2 cases), CA 2 (1 case), and enterovirus 71 (1 case) have been confirmed. 

In terms of international outbreaks, a nationwide outbreak of enterovirus D68 infection occurred in the United States during August 2014 and January 2015 and a cumulative total of 1,153 cases of cases with a significant number of severe cases were confirmed during that outbreak. Canada and Argentina respectively isolated enterovirus D68 in 2014 and 2016, and only a few sporadic cases developed severe complications. Over 15 countries in Europe isolated enterovirus D68 during 2010 and 2016. Among those countries, Germany, the United Kingdom, France, Italy, the Netherlands, Portugal, Norway and Sweden reported sporadic cases that developed severe complications. Countries in Southeast Asia observed an increase in the number of acute respiratory infection cases caused by enterovirus 68 during 2005 and 2014 and all of them were mild cases. Japan confirmed 258 mild cases of enterovirus D68 infection and 9 severe cases in 2015.
Enterovirus D68 infection is transmitted through the fecal-oral route, respiratory droplets and direct contact. The primary symptoms include, fever, runny nose, and cough. A few infected individuals may develop complications such as pneumonia, encephalitis and limb weakness. Currently, there is no effective vaccine to prevent or drug to treat the infection. Hence, the public is urged to practice good personal hygiene, wash hands with soap and water properly and frequently. If a child in the family develops limb weakness, please ensure the child receive medical assistance as soon as possible. 

The most effective ways to ward off enterovirus D68 and other enteroviruses are to practice good hand hygiene and cough etiquette, avoid visiting crowded public places, and rest at home when sick. 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).

Last modified at 2017-12-12

Complicating matters slightly, reports of seasonal flu are on the rise in Taiwan (see CDC statement Domestic flu epidemic rise, reminding people to enhance personal protection ), which may make early diagnosis of NPEVs more challenging.

Some earlier blogs on EV-D68 and other NPEVs include:
MMWR: Cluster of Acute Flaccid Myelitis in Five Pediatric Patients - Arizona, 2016
CDC Acute Flaccid Myelitis Update - January 2017

EID Journal Upsurge In EV-D68 In The Netherlands, 2016

Taiwan CDC: 1st Case Of EV-D68 With Acute Flaccid Paralysis 

ECDC: Rapid Risk Assessment On Recent Enterovirus Outbreaks In Europe


No comments: