No 46 - 2013

Polio in Syria

The current polio outbreak in Syria has attracted a good deal of press coverage and reflections as to whether the condition may spread with the flow of refugees from Syria into other countries within the region or to European countries, including Denmark. Polio was last detected in Syria in 1999.

At present, a total of 22 cases of acute flaccid paralysis (AFP) have been reported in children in the Deir al-Zour province in North-Eastern Syria, and the WHO has confirmed polio caused by wild poliovirus of type 1 in 13 of these children. Symptom onset in the most recent case occurred on 4 October.

As infection with polio virus only causes polio with paralysis in approx. 1/200 infectees, the finding of at least 13 polio cases therefore means that nearly 3,000 persons may have been infected and may therefore excrete virus in their stools for a 3-5-week period, the overwhelming majority of whom will not themselves experience any symptoms.

Genetic testing of the virus has demonstrated considerable similarity with a virus detected in wastewater in Egypt in December of 2012, which, in turn, seems to have originated from Pakistan. Wild poliovirus very similar to the current virus has also been found in wastewater in Israel, on the West Bank and in the Gaza Strip since February 2013, EPI-NEWS 38/12. Furthermore, the virus has been found in the stools of several fully vaccinated and symptom-free persons, but at present no polio cases have been detected in these areas.

Both the WHO and the ECDC (The European Centre for Disease Prevention and Control) have assessed that there is a considerable risk that polio may spread to other countries in the region as about one million Syrians have fled into these countries. Potentially, there is also a risk of spreading to the European countries which have received Syrian refugees.

In Syria and its neighbouring countries Lebanon and Turkey, large-scale vaccination campaigns are currently being implemented to protect all children and thereby stop the outbreak. These mass vaccinations comprise about 22 million children in the region and will continue for the coming 6-8 months depending on how the outbreak develops. In addition to the efforts made in Lebanon and Turkey, vaccination campaigns will also run in Jordan, Egypt and in the Palestinian territories.

In Denmark, the Danish Health and Medicines Authority has ensured registration of the locations where Syrian refugees to Denmark were received. Furthermore, the Authority has ensured that current guidelines on vaccination of Syrian - as well as any other - refugee children from polio endemic areas are being followed. Recommendations for revision of the Danish childhood vaccination programme for children arriving to Denmark are presented in EPI-NEWS 2/11.

Denmark has had an effective polio vaccination programme in place for nearly 60 years, and the population immunity is generally considered as being good. However, in view of the approx. 90% vaccination coverage observed in recent years for the first three IPV vaccinations, EPI-NEWS 21/13, at its latest meeting in the European Regional Certification Commission for Poliomyelitis Eradication held in late May 2013, the WHO downgraded Denmark from being a low-risk country to being an middle-risk country with regard to spreading of polio should the virus be introduced.

Despite the fact that the vaccination coverage is a minimum estimate, EPI-NEWS 20/12, it is important that even more children are vaccinated to keep polio from spreading in Denmark in the event that the virus is introduced into the country. Provided that political support may be gained for such an initiative, a system ensuring that parents are reminded that they should have their children vaccinated may hopefully contribute to an even higher coverage.

Globally, polio is closer to being eradicated than ever before, EPI-NEWS 34/12. In 2012, the number of polio cases detected was the lowest ever (223) compared with the approx. 350,000 cases recorded when the polio eradication campaign was initiated in 1988. Globally, 2013 had seen a total of 328 polio cases by 6 November; 116 in the three remaining endemic countries - Afghanistan, Pakistan and Nigeria - and 212 in non-endemic countries, primarily in Somalia (180 cases) due to an outbreak on the Horn of Africa which started in the beginning of this year.

In Denmark, intensified monitoring of enterovirus of which poliovirus forms part has been in place since 1998. The objective of the monitoring has been to demonstrate that Denmark is completely free of polio and to detect and confirm any suspicion of infection or import of poliovirus, EPI-NEWS 19-20/01. The monitoring is effected in close collaboration between doctors in general practice and at hospitals across Denmark on the one hand and epidemiologists from the Department of Infectious Disease Epidemiology and virologists from the national WHO Poliovirus Reference Laboratory at Statens Serum Institut on the other.

Laboratory monitoring efforts include very sensitive testing of samples for poliovirus DNA material and typing of such material (through PCR diagnostics and sequencing) and also virus culture in three cell lines and finally further virus characterisation. The laboratory reports its enterovirus monitoring data to the WHO on a weekly basis. No cases of wild polio virus have been detected in the approx. 21,000 samples tested since monitoring was initiated. Along with the rest of the WHO European Region, Denmark has been declared free of polio since 2002.
(P.H. Andersen, Department of Infectious Disease Epidemiology, T. K. Fischer, Virology Surveillance and Research)

Mumps virus still in circulation in Denmark

The mumps is caused by parotitis virus infection. Since the introduction of the MMR vaccine in 1987, the number of mumps (parotitis) cases in Denmark has dropped drastically. In the 2002-2012-period, an average 13 annual cases were notified.
In 2013, Statens Serum Institut (SSI) has recorded an increase in the number of notified/laboratory-confirmed mumps cases, EPI-NEWS 24/13. New cases are detected continually, and the SSI has knowledge of 47 laboratory-confirmed mumps cases in Denmark at present, which is the highest number seen since 1994. Of these cases, 41 have currently been notified.

The first case was detected in February, in March six cases were found, in April seven, and in May a total of 11 cases were detected. In the course of the summer, only few cases were detected, but in September four cases were found and in October seven cases were detected, indicating that mumps virus continues to circulate in Denmark. The cases are spread across Denmark, but with a clear predominance of cases in the Capital Region of Denmark as 24 (59%) of the 41 cases were recorded in this region.

Since the introduction of the MMR vaccine, the age of the persons affected by the disease has generally increased, and the days when mumps could exclusively be considered a childhood disease are over. This also applies to the current cases among whom 34 of 47 are older than 20 years of age. The risk of complications increases with increasing age. Among the 41 notified cases, five (12%) had orchitis and one (2.5%) had serous meningitis in connection with the condition. Vaccination status is available for 36 persons, 15 (42%) of whom had reportedly received one mumps vaccination and five (14%) of whom had received two vaccinations.

The best prevention against the mumps is MMR vaccination, which forms part of the childhood vaccination programme. The mumps component of the vaccine, however, is not quite as immunogenic as its two other components, as only approx. 85% form protecting antibodies after a single vaccination. Nevertheless, high vaccination coverage will lead to good population immunity. Internationally, outbreaks have been described even among well-vaccinated population groups, and it should be expected that the share of vaccinated individuals may be relatively high during an outbreak in an area in which the majority of the population have been vaccinated. Taking measles as an example, a good description of this paradox is available on the ECDC's website (page 7-8).

Physicians are still encouraged to pay particular attention to the diagnosis in children and younger adults who present with symptoms that are compatible with mumps. Suspicion may be confirmed by blood sample testing for IgG and IgM antibodies, but the diagnosis is established though PCR detection of parotitis virus in a throat swab, nasopharyngeal secretion and/or urine (or blood). All samples testing positive for parotitis virus are sent free of charge to Virology Surveillance and Research at the SSI, which is responsible for national monitoring, including typing and sequencing of parotitis virus.

Mumps is individually notifiable on Form 1515. The condition is notifiable by clinical diagnosis and concurrent detection of virus and/or specific antibodies.
(L.K. Knudsen, P.H. Andersen, Department of Infectious Disease Epidemiology, J. Fonager, F.N. Engsig, T.K. Fischer, Virology Surveillance and Research)

Adverse reactions associated with MMR vaccination

Following a public tender, as from week 25 the SSI changed its 2013 MMR vaccine to the MMR VaxPro®, EPI-NEWS 24/13. In the period following the introduction of the new vaccine, the SSI has received a number of reports from physicians reporting that the vaccinated child reacts with discomfort and crying at/after the injection. MMR VaxPro® has previously been used in the childhood vaccination programme up to 2008, and its adverse reaction profile is comparable to that of Priorix®, which was disbursed in the 2008-2013 period, EPI-NEWS 38/08.

According to the approved summary of product characteristics for MMR VaxPro®, it is injected either intramuscularly (IM) or subcutaneously (SC). The preferred injection sites are the anterolateral area of the thigh in younger children and the deltoid area in older children, adolescents and adults. However, the vaccine should be administered subcutaneously in patients with thrombocytopenia or any coagulation disorder.

In a pre-marketing clinical trial, the MMR VaxPro® was administered either intramuscularly or subcutaneously. The general safety profile of either administration route was comparable, although injection-site reactions were less frequent in the IM group (15.8%) than in the SC group (25.8%).

The most common adverse post-marketing reactions reported in association with MMR VaxPro® are fever (38.5 °C or above) and reactions at the injection site, including pain, swelling and erythema, which occur in ≥ 1/10 of vaccinees. Brief burning and stinging at the injection site were reported at an unknown frequency.

Based on the reported adverse reaction profile, MMR VaxPro® should therefore be given intramuscularly unless another mode of administration is required, as mentioned above.
(The Consultancy Team, Department of Infectious Disease Epidemiology)

European Antibiotic Awareness Day and national Danish antibiotic campaign

18 November 2013 will see the celebration of the sixth European Antibiotic Awareness Day; a joint European initiative which counts the participation of 43 countries, see www.ecdc.europa.eu.

The European Antibiotic Awareness Day is an annual event designed to increase awareness of the appropriate use of antibiotics. In connection with the day, this year will see the launching of a national Danish antibiotic campaign to increase awareness of the correct use of antibiotics in Denmark. One of the campaign's target groups is general practice patients, and the campaign comprises material in the form of the poster "Many infections will pass spontaneously without antibiotics" and the website www.antibiotikaellerej.dk.

This year's campaign also comprises banners at netdoktor.dk and apoteket.dk, video clips shown on flat screen monitors at pharmacies and ads, among others in the Danish magazine "Sundhed" (Danish for "Health").

The campaign is financed by means from the Danish Antibiotics Council and implemented as a cooperative activity counting the Danish Ministry of Health, the Danish Medical Association, the Danish Health and Medicines Authority and Statens Serum Institut.
(L. Skjøt-Rasmussen, R. Skov, Microbiology and Infection Control, B. Jørgensen, Digital Communications)

Link to previous issues of EPI-NEWS

13 November 2013