Four major outbreaks of Enterovirus 71 infection in the world were traced respectively to Bulgaria in 1975, Hungary in 1978, Malaysia in 1997 and Taiwan in 1998.
Taiwans statistics covering the period from 1998 to 2005 indicated that children under five years of age were the most vulnerable to severe enterovirus infection. Mortality, in fact, was the highest in this age group. Seventy-eight deaths were reported in 1998, 41 deaths in 2000 and 58 deaths in 2001.
The case fatality rate was from 10.6% to 25.7%, according to the Department of Health. Enterovirus 71 mainly accounted for the severe cases of infection and illness, followed by coxsackievirus. Summer likewise saw the outbreak of the viral throat infection called herpangina and hand, foot and mouth disease in its full-blown version.
Increase in the cases of enterovirus infection was usually noted during the second half of March. This was observed to peak towards the end of May until mid-June. Another surge took place after school opened in October. Victims died of fulminant pulmonary edema within 2-3 days after onset of disease.
"A physician-based sentinel surveillance system for enterovirus has been put in place since 1998," said Dr. Chang-Hsun Chen, director of the second division at the Center for Disease Control under the Department of Health.
"More than 500 physicians in clinics and hospitals throughout the island help the center collect information on enterovirus incidence. The year-round incidence of enterovirus, whether rising or falling, is monitored through this network. If you look at the chart on infection prevalence, enterovirus has never completely disappeared."
He went on: "Twelve medical centers and big hospitals are also under contract to carry out enterovirus-related laboratory experiments. We need to keep tabs on the ratio of the enterovirus types or strains during outbreaks. Enterovirus 71 is our main concern."
Chen spoke of the possibility of a virus mutating to a form with increased virulence. The work of the sentinel surveillance system has to be coupled with awareness on the part of the health care workers.
Enterovirus 71 had circulated in Taiwan for at least 16 years before 1998. The year 1998 saw the biggest and most alarming enterovirus outbreak in Taiwan. A total of 405 severe cases were reported. Hand, foot and mouth disease was manifested in most cases in this particular year. Herpangina, however, dominated the enterovirus outbreaks in the other years.
The prevalence of enterovirus in Taiwan pointed to the susceptibility of children depending on their age. Babies under one year of age made up the biggest group, followed by children aged one to five. Enterovirus 71 emerged as the No.1 killer.
"Counties and cities now must deal with the question of whether to suspend classes for one to two weeks during enterovirus outbreaks," said Chen.
"Two cases of the highly contagious infection are enough to warrant such a decision. The class suspension period is decided via complete assessment, taking epidemic and social factors into consideration."
Chen reported that Malaysia, currently facing an enterovirus epidemic, has decided to close down 500 kindergartens.
The educational campaign to prevent the spread of enteroviruses of which there are 68 serotypes in Taiwan taps government and private resources. According to Chen, the MacDonalds fastfood chain, through its foundation, has been a partner of the government in the islandwide campaign on enterovirus prevention. Its entertaining skit goes around to promote handwashing. Health officials also put in an appearance on such occasions.
The general public has to be better informed about enterovirus and how it is transmitted in order to stop its spread. Information dissemination helps curb panic. A constant focus of the information campaign is the need to cultivate the habit of washing hands. This is a good way to prevent getting infected with enterovirus. Health and hygiene practices in everyday life go a long way in cutting down infection risk.
The information campaign also teaches the public to strengthen their immune system through healthy diet, exercise and enough sleep, according to Chen. Avoiding exposure to infection through contact is another point raised.
Seminars, lectures and occupational training of medical personnel organized by medical associations help raise the ability to diagnose infection as well as heighten professionalism, according to Chen.
Spreading knowledge about enterovirus prevention has the effect of lowering infection risk. This also leads to early diagnosis, treatment and recovery, bringing down altogether risks of complications and even death.
Enterovirus-related research is being encouraged. The development of a vaccine to prevent future enterovirus outbreak is being given push.
But as Chen put it, the time-consuming development process for eventual safe introduction of the vaccine into the market takes 10 years or longer. Training more people for such research will improve infection prevention as well as disease diagnosis and treatment.
Taiwan after shock of 1998 more ready to deal with virus
"Enterovirus comes and goes but who knows, one day the virus may just disappear," said Dr. Ping-Ing Lee, associate professor from the Department of Pediatrics at the National Taiwan University Hospital.
He went on: "Every year since 1998, more than 10 of the over 60 identified subtypes turned up although some were more predominant than others. In 1998, enterovirus 71 was the most common. Last year coxsackievirus B topped the list but with less cases of death reported."
He described the disease: "The illness caused by Enterovirus 71 lasted for about one week with the most critical period spanning three to four days. Statistics gathered in 1998 showed that 80 percent of cases who died after being brought to the hospital died within 24 hours.
Almost all were under five years of age. These children came from outside Taipei City and Kaohsiung City, suggesting a difference in lifestyles in urban and rural areas had some bearing on the prevalence in different places."
Adult infection
Lee, who wrote and published "The Enterovirus Shock" after 1998, warned adults to watch out for they could also get infected. He observed:
"Children were bombarded with reminders to wash their hands. What happened was that the adults who talked a lot about it were themselves not washing their hands as much as they should. They neglected the healthy habit, thinking they wont get sick. In fact, many adults were infected with enterovirus in 1998."
Lee cited the case of a grandfather who got the infection after taking care of his two grandchildren in 1998. He developed aseptic meningitis.
Lee remarked also that the large-scale handwashing campaign consequently brought down prevalence of infections caused by other highly contagious viruses, too.
Painful ulcers
Diagnosis of enterovirus was easily done through the vesicles, which burst into ulcers in the mouths, according to Lee. The painful sores were in the rear of the mouth and less in front in cases of herpangina.
The sores could be in front and at the back in cases of hand, foot and mouth disease. These vesicles were also seen in the hands and feet. He said that such outbreaks were not to be confused with itchy chicken pox blisters, which were distributed mainly in the chest or trunk of the body.
Lee singled out dehydration as a most common complication of the hospitalized cases. He elaborated: "First to be noticed was the considerable decrease in urine. The child, too, cried without shedding tears. Lips were parched."
High fever was a symptom, indicating the body was building up its immune system, according to Lee. As for sores in the mouth, the number could be as high as 50 or more. These were different from the fungal infection called thrush.
Enterovirus 71 was the most dangerous, according to Lee. Coxsackievirus B was not as deadly. Lee remembered patients complaining about chest pain. He found them to have epidemic pleurodynia. Some cases died of heart failure from myocarditis.
Hemorrhagic conjunctivitis has not been seen for more than 10 years, according to Lee. Eye symptoms were not common in the outbreaks since 1998.
Supportive care was found to be very important during the critical period. Lee, in fact, announced that none of his patients with Enterovirus 71 died. He warned though that a patient could end up ventilator-dependent. The brain-affected case could also suffer permanent movement problems.
Need for information
After the enterovirus outbreak in 1998, there was a scramble for information about the infection caused especially by Enterovirus 71. Specialists in different fields of medical practice were compared to the blind men groping and drawing different conclusions about the shape of an elephant in the classic tale.
Some studies were focused on the heart, others on the lungs and the heart, and still others on the brain. A complete picture was clearly lacking, according to Lee.
Health workers tried with great difficulty to convince the families of the cases who died to allow autopsy to take place to help further the cause of medical research.
Legislation on highly contagious diseases finally had to be amended to oblige families to agree to a request for autopsy on their loved ones so that studies could be carried out to prevent the spread of a highly contagious disease, pointed out Lee.
"Whenever our pediatricians travel abroad to attend international conferences, they are often asked about our 1998 experience," said Lee.
"We have earned the highest respect for our scientific investigations and researches on enterovirus, which were in some way spurred by public panic which the media helped sow through alarming headlines at the height of the epidemic."
Prevention Tips
There are many strains of enterovirus. Infection does not rule out future recurrence. Until now, no vaccine against enterovirus (except poliovirus) has been developed. Transmission takes place through the mouth, droplets and contact. Its spread is not easy to check.
The public must take note of the following prevention tips:
1. Children under three years of age have a higher risk of developing aseptic or viral meningitis, poliovirus or pleurisy after catching the disease.
2. Improve personal immune system. Pay attention to nutrition. Take up sports. Get enough sleep.
3. Emphasize personal hygiene. Know the right way to wash hands. Protect self from infection and avoid passing on infection to babies and toddlers with low immunity through contact.
4. Pay attention to the sanitation of surroundings: Make sure that the environment is always clean and that the ventilation system works.
5. Avoid direct contact with those with enterovirus: Stay away from crowded public places. Avoid contact with enterovirus patients, their families or classmates.
6. When there is suspicion of infection due to appearance of certain symptoms, consult a doctor.
What to do when a family member is found to have the illness
Families of those suffering from enterovirus must pay attention to the following:
1. Carefully dispose of and clean up secretions like saliva, sputum and nasal mucus as well as stool of the infected person. Once done, wash hands thoroughly.
2. Increase intake of fluids. Children infected with enterovirus should stay home and avoid passing on the infection to classmates.
3. The second family member to be infected with the disease is very likely to be a more serious case than the first one because of his/her exposure to more germs (virus).
4. As soon as the patient shows the following symptoms, he or she should quickly seek medical attention:
a.) Drowsiness, confusion, lethargy, as well as loss of strength on hands and feet, all suggesting that the tissues covering the brain and spinal cord are affected, are symptoms appearing on the second to the fourth day.
b.) Fits or convulsions.
c.) Nausea and vomiting.
d.) Fever, sluggishness, irritability or fretfulness, disorientation, drowsiness, neck stiffness, muscle numbness, clonic jerks, breathlessness, general malaise, as well as fast and irregular heartbeats.
5. Those with infection should avoid contact with pregnant mothers, newborn babies and children especially those under three years of age.
Cooperation expected of nursery and day-care center personnel:
1. Parents should be provided information on the prevention and treatment of enterovirus. The teaching staff needs an understanding of the enterovirus infection process. Such knowledge should be passed on through the parents of the children, during visits with the families of the children, through the school diary for keeping in touch with the families and through simple information handouts.
2. Clean toilets and sinks for washing hands should be provided. Clean running water and soap bars or liquid soap should be available. Cultivate in the toddlers and children the good habit of washing hands. Each classroom should be kept clean and well-ventilated. The number of students should be limited to avoid creating a crowded space.
3. Do not allow furry toys. Playthings should regularly be disinfected, washed and dried.
4. Cleaners should wear masks and gloves when carrying out washing and disinfecting chores especially in the toilet area. Once they are done with the cleaning, they should remove the masks and gloves, taking care not to bring them in contact with objects to avoid contamination.
5. When changing the diapers of babies and toddlers, remember to wash hands thoroughly before and after. Dispose of the soiled diapers properly.
6. Monitor closely the health conditions of the children. Investigate absences. If children show certain symptoms, contact the parents. Dont ignore suspicions of enterovirus infection.
7. Children suspected of having enterovirus should be watched closely. Attention should be paid to their individual health habits. Their close contact with other children should be prevented. Consultation with medical doctors should be suggested. Communication with parents should continue for the purpose of convincing them to keep their children at home for at least one week or until fever has completely disappeared.