The investigation into the recently reported illnesses and deaths in Cambodia concluded that a severe form of hand, foot and mouth disease (HFMD) associated with enterovirus 71 (EV-71) was the cause in majority of the cases reported to the Ministry of Health (MoH).
Based on the investigation, a total of 78 cases were identified (including the 62 cases with 61 deaths reported by Kantha Bopha Hospital, the rest came from other hospitals). Of the 78 cases, 61 fitted the criteria used, which were children <12 years of age with fever and neurological and respiratory symptoms within 7 days of onset. Of the cases reviewed, 54 had died.
The number of cases and deaths will mostly likely change in the coming days as the government, with support from WHO, has enhanced its surveillance for neuro-respiratory syndrome, a key syndrome observed among patients with severe HFMD caused by EV-71.
The investigation included a thorough review of the hospital records of the patients from Kantha Bhopa as well as other hospitals, laboratory tests, active follow-up with the affected families by the local Rapid Response Teams (RRT) as well as evaluation of the data from national surveillance system.
Samples from a total of 31 patients were obtained and tested for a number of pathogens by Institut Pasteur du Cambodge. Of these, majority tested positive for enterovirus 71 (EV-71) which causes HFMD. A small proportion of samples also tested positive for other pathogens including Haemophilus Influenzae type B, dengue and Streptococcus suis. It was not possible to test all the patients as some of them died before appropriate samples could be taken.
The investigation revealed that most of the cases were under 3 years old. Majority of them suffered from chronic conditions and malnutrition.The cases were from 14 different provinces and many of them were given steroids at some point during their illness. Out of the 61 patients that fitted the case investigation criteria, 48 were found to have been given steroids. Steroid use has been shown to worsen the condition of patients with EV-71.
(The 14 provinces with severe HFMD cases are: Kampong Cham, Kampong Speu, Prey Veng, Phnom Penh, Takeo, Kandal, Kampong Chhanang, Kampot, Kratie, Svey Rieng, Kampong Thom, Mondolkiri, Pursat and Battambang)
This is the first time that EV71 was identified in a lab in Cambodia. HFMD was seen in Cambodia before.
Travel advice and border control
WHO is not recommending travel restrictions related to this event in Cambodia. Returning travelers who become ill should contact their health care provider as per regular practice.
IHR and notification of this event
The Ministry of Health (MoH) notified WHO about this event through the International Health Regulations (IHR) notification mechanism as it met the criteria for notification of any event where the underlying agent or disease or mode of transmission is not formally identified. WHO was notified about this on 1 July and communicated it to IHR national focal points (NFP) via the Event Information Site (EIS). WHO is obliged to share information with other Member States once we receive notification of this nature.
Under the IHR (2005), notification is based on the assessment by the country, of an event within their territory that may constitute a public health emergency of international concern. These include:
- Events, irrespective of their origin or source, including those caused by biological (of infectious or non-infectious nature) chemical agents or radio nuclear materials;
- Events where the underlying agent, disease or mode of transmission is new, newly- discovered or as yet unknown at the time of notification;
- Events involving transmission or potential transmission through persons, vectors, cargo or goods (including food products) and environmental dispersion;
- Events that carry potential future impact on public health and require immediate action to reduce the consequences;
- Events arising outside of their known usual occurrence patterns.
During the investigation, WHO and MoH referred to it as an unknown disease or undiagnosed syndrome and considered many possibilities for the causes of the illnesses and deaths.
We have no information about this. What we know at this time is that there has been no report of hospital transmission – no neighbouring patients or health care worker have similar signs or symptoms.
The government, with support from WHO, has its enhanced its surveillance for neuro-respiratory syndrome for the next 4 weeks (starting first week of July). The enhanced surveillance is intended to detect both severe and mild cases and done in health centers throughout the country. Sentinel surveillance for severe cases will also start in a number of provincial and national hospitals. (As part of the enhanced surveillance, sporadic cases will be reported. This is normal. But NOT all cases reported will be EV-71 and final confirmations will be done by lab tests.)
Training for all health staff, begins on Monday by experts from China.
Health centres will report cases of HFMD to the MOH on a weekly basis. The Ministry of Health, with technical support from WHO and other partners is developing risk communication messages for health centers nationwide and preventive messages for the general population. Information, Education and Communication materials will also be developed and distributed to all health centers in the country.
In addition, MoH with support from its partners, is following up laboratory testing to identify which subgenotype of EV71. The government is also developing guidelines and training courses for management of patients with mild and severe forms of HFMD. The MoH is also working on campaigns to raise awareness on prevention, identification and care of children with HFMD.
What is HFMD
HFMD is a common infectious disease of infants and children. It is not a new disease in Cambodia and is seen in many countries across the world. Nearly all patients recover in 7-10 days without medical treatment and complications are uncommon.
HFMD is different from Foot-and-Mouth Disease (FMD) which affects cattle. HFMD is not transmitted to or from pets or other animals.
HFMD is caused by enteroviruses, most commonly by coxsackievirus which usually results in mild and self-limiting disease. HFMD can also be caused by enterovirus 71 (EV-71), some of which can cause serious complications and lead to death.
Early signs of HFMD infection
The disease usually begins with a fever, poor appetite, malaise, and sore throat. Skin rash develops over 1-2 days with red spots, some with blisters on the palm, hands, soles of feet, and sometimes on buttocks or genitalia.
Treatment of children with HFMD
There is no specific treatment for HFMD. Patients should drink lots of water and may require treatment according to their symptoms to reduce fever and pain from ulcers.
Prevention of HFMD
Good hygiene practice can prevent HFMD. Frequent washing of hands with soap and water, especially after touching any blister or sore, before preparing food and eating, before feeding young infants, after using toilets and after cleaning children.