ECDC: RRA On Imported Monkeypox Cases From Nigeria

 
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Over the past several days we've learned a great deal more about the two imported cases of Monkeypox into the UK from Nigeria, and about the coordinated public health responses from the UK, Nigeria, and other EU nations.

Nigeria: CDC Monkeypox Update Epi Week 37

Eurosurveillance Rapid Comms: Two cases of Monkeypox imported to the UK

Report: UK PHE Imports Smallpox Vaccine For HCWs Caring For Monkeypox Cases

In the fall of 2017, Nigeria saw their first confirmed Monkeypox outbreak in nearly 40 years, resulting in more than 200 confirmed and suspected cases. While that outbreak was reportedly quelled in February, a small number of isolated cases have continued to be reported over the past 6 months.

Fortunately, the West African Monkeypox virus is considered to be less virulent, and less easily transmitted, than its Central African counterpart (cite).

Nevertheless, the importation of any infectious disease into a country where community immunity is believed very low, is a concern.  And the importation of two separate Monkeypox cases in a matter of a few days - when no cases had ever been seen in the UK before - quite unusual.

Hence the vigorous response from public health.

As reflected in the ECDC chart above, nearly 50,000 people arrive to EU countries from Nigeria each month, with the vast majority of those ending up in the UK.  Other African nations (Cameroon, DRC, Sierra Leone, Liberia & Central African Republic) where Monkeypox outbreaks have been reported provide nearly 400,000 annual EU visitors.

As we've seen with recently imported cases of MERS in South Korea and the UK, and with briefly quarantined flights in the United States (for flu), international air travel is a highly efficient way to spread any infectious disease (see JFK Quarantined Flight & Airport Screening For Infectious Diseases).

Although hyperbolic headlines in the tabloid press have badly overstated the current threat, the risk of seeing additional cases arrive - or even limited transmission to close contacts in the EU - is not zero. 

On Friday the ECDC published a Rapid Risk Assessment (RRA) on the UK's imported Monkeypox cases, excerpts from which I've posted below.  By all means, follow the link and download the full document.

RAPID RISK ASSESSMENT
Monkeypox cases in the UK imported by travellers returning from Nigeria, 2018
21 September 2018

(EXCERPTS)

Situation in the rest of West and Central Africa in 2018

Cameroon: On 30 April 2018, two suspected cases of monkeypox were reported to the Directorate of Control of Epidemic and Pandemic Diseases (DLMEP) by the Njikwa Health District in the Northwest Region of Cameroon bordering Nigeria. On 14 May 2018, one of the suspected cases tested positive for monkeypox virus by PCR. On 15 May 2018, an incident management system was set up at the National Emergency Operations Center. An investigative mission to the Northwest and Southwest Regions from 1 to 8 June 2018, found 21 new suspected cases without active lesions. As of 13 June 2018, a total of 36 suspected cases have been reported from both the Northwest and Southwest Regions [30].

Central African Republic: The outbreak was officially declared on 17 March 2018 in the sub-province of Ippy, Bambari district. Since the beginning of the outbreak, three districts have been affected, namely Bambari, Bangassou and Mbaïki districts. Cumulatively, 40 cases of monkeypox with one death (CFR 2.5%) have been reported from 2 March to 22 August 2018 in the country and 13 cases have been laboratory confirmed out of 23  samples tested. No new cases have been notified in the three districts after the end of the epidemic.

Democratic Republic of the Congo: From weeks 1 to 33, 2018, there have been 2 585 suspected cases of monkeypox, including 42 deaths (CFR 1.6%). Suspected cases have been detected in 14 provinces. Sankuru Province has had a remarkably high number of suspected cases in 2018.

Liberia: Since the beginning of 2018 and as of 19 August, four suspected cases have been reported from Sinoe, Rivercess, Nimba and Maryland Counties [31].

Sierra Leone: In April 2017, an isolated case of monkeypox was confirmed in Pujehun District, Sierra Leone. This is the third known occurrence of monkeypox in the country, with the first reported case in 1970 and the second in 2014 [32].

ECDC risk assessment for the EU

The notification of imported cases in Europe is not unexpected due to the circulation of monkeypox virus in West and Central Africa and the travel volume pattern observed from this region into the EU.

According to the International Air Transport Association (IATA) database, over half a million people travelled from Nigeria to the EU Member States in 2017. Among these travellers, the UK has the highest travel volume of passengers from Nigeria (59%), followed by Italy (9%), Germany (7%) and Ireland (6%). France, the Netherlands, Spain and Sweden account for less than 5% each. In total, these eight countries accounted for 93% of the travellers from Nigeria to the EU in 2017 (See Annex 1). In 2017, travellers came from other countries with reported monkeypox virus circulation to the EU Cameroon (215 658), DRC (97 380), Sierra Leone (40 023), Liberia (29 768) and Central African Republic (10 853).

The notification of two imported cases in a short period of time could indicate an enhanced circulation of monkeypox virus in West Africa in 2017 to 2018. This is supported by continuous reports of sporadic cases in Nigeria after the outbreak reported in late 2017 and the notification for the first time of an outbreak in southern Cameroon in 2018.

Risk of introduction and further spread within the EU/EEA

The risk of new introductions of monkeypox to Europe depends on the extent of the circulation of the virus in Nigeria and other countries in West and Central Africa. Cases continue to be reported from several countries, but present information indicates that the peak of the outbreak in Nigeria occurred in October 2017.

Overall, the likelihood of monkeypox importation to Europe remains very low, but new travel-related cases into EU/EEA countries cannot be excluded. Therefore, public health professionals should follow the development of the situation in West and Central Africa and maintain healthcare awareness about  the risk of occurrence of potential monkeypox cases among individuals travelling back from affected areas with compatible clinical presentation.

With regard to this event, due to the epidemiological link with Nigeria, the West African clade is expected to be the aetiological agent, pending genomic confirmation. The risk of spread in the EU/EEA is very low due to the moderate transmissibility of the disease reported to date, its distinctive clinical picture − although physicians should be aware of the similarities with and differences from varicella and other poxvirus infections in humans − the available laboratory capacity in Europe for rapid diagnostic and capacities for appropriate management of cases and their contacts in EU/EEA countries.

Risk of infection with regard to different settings for EU/EEA citizens

In the community, the risk of transmission is considered negligible.

The individual risk of infection through contact with a patient depends on the nature and duration of the contact. Close contacts (e.g. immediate neighbour on aircraft, family members with close contact), or persons who have provided care to patients, including HCWs whoo have not applied preventive measures, have a moderate risk for infection. Consequently, HCWs and others caring for patients should implement necessary precautionary measures to reduce the risk of infection.

(Continue . . . )

For a more detailed look at the Monkeypox virus in Africa, and a limited 2003 outbreak in the United States - you may wish to revisit this blog from last May.

MMWR: Emergence of Monkeypox — West and Central Africa, 1970–2017