Introduction

In 2010, polio outbreaks occurred in countries in Central Asia that had had no previous outbreaks (e.g., Tajikistan, Kazakhstan, and the Russian Republic) [1]. Korea has no report of patients infected with wild poliovirus since 1984 [2], but the possibility of outbreak due to imported cases has prompted establishment of the National Action Plan (NAP) for response to poliomyelitis importation [3]. Since then, there was an outbreak in the province in China which borders Pakistan in 2011 [4]. Concerns about imported poliomyelitis and the response plan in Korea has led to the 2010 NAP being reconsidered. As a result, more concrete and systematic contents are necessary to enhance the 2010 NAP.

The revision of the 2010 NAP with consideration of foreign cases was arranged and discussed by the Polio National Certificate Committee (NCC). This paper aims to introduce the NAP revision process with this background.

Process of the Revision of the NAP

The 2010 NAP cannot be evaluated and revised based on performance with real patients, therefore we have selected the items for revision through literature reviews, field health workers comments, and experts’ advice. In this revision we aim to provide specific guidelines to each agency and agent for systematic responses on a case-by-case basis in the event of an epidemic in Korea. The revision was discussed and confirmed by the first polio NCC.

Results

3.1. 2010 NAP evaluation

The 2010 NAP is composed of five category: surveillance, investigation, risk assessment, outbreak response, and evaluation/documentation. Outbreak response, the key domain, is divided and described into six subgroups and includes the work sheet to characterize the patient’s epidemiology and trace the contacts.

The 2010 NAP includes a basic principle for management of infectious disease epidemics and the laboratory diagnosis, duration of isolation, classification of the contacts, and immunization proposed on a medical basis. Furthermore, it includes the advisory committee’s review and risk of communication to consider the impact one patient might make when there has been no case in Korea since 1984.

However, management and surveillance could be fortified by patient phase but it is not suggested because we do not have a specific standard between suspected and confirmed patients. Also, the level of management of the contacts should change by intensity of contact. We intended to minimize possible overreactions in cases of low transmission. Outbreak response should be simultaneous and comprehensive by related agencies, and it is necessary to provide comprehensive reactions by agency countermeasures for prompt and systematic responses (Table 1).

3.2. Major revision

3.2.1.

3.2.1. Countermeasures by patient phase

Polio case is a significant matter in public health and society, so that an active rapid containment strategy in the early stage is necessary, but over-countermeasures in the low transmission stage should be minimized. In this regard, patients are classified into suspected and confirmed cases and major countermeasures are structured in the key components of response, patient management, contact management, and surveillance fortification.

The suspected cases are treated under isolation while the stool test is being examined. The contacts are vaccinated and undergo hygiene education and the area is placed under intensive surveillance. If the suspected case is identified as a confirmed case, then he/she should undergo the isolated treatment and the stool test every week for loss of infectivity. The contacts are isolated, tests are taken for confirmation with additional vaccination, and the intensive surveillance area is expanded to the whole nation (Table 2).

3.2.2.

3.2.2. Role of agency

If a case is reported, the major response agencies are classified into treatment, field response, central coordination, and expert committee. The necessary countermeasures are determined by patient phase. Significant matters in the public health perspective require the expert committee’s approval (Table 3).

3.2.3.

3.2.3. Criteria of classification and management of the contacts

The situation and intensity to contact a patient varies. The 2010 NAP only classified contacts on a general level (”household”, “healthcare workers (HCW)”, ”public”), with no consideration of other situations and the intensity of contact.

In the revised 2012 NAP, ”toilet contact” was added, which considers those who shared the same toilet with the patient in the infectious period. Among HCW contacts, the person who contacts the patient with personal protective equipment belongs to public contact. Due to the high possibility of importation, passengers in the same airplane or ship are included in the contact classification.

Intensity of contact occurs in the descending order of: household contact, toilet contact, HCW contact, and pubic contact. The highest risk contacts (household contacts) are quarantine in the home and perform confirmation tests and immunization. The next highest risk contacts (toilet contact and HCW contact) are to take a confirmation test and immunization without quarantine. Finally, those who have had public contact receive immunization only (Table 4).

3.2.4.

3.2.4. Immunization

According to the 2010 NAP, contacts with a complete polio immunization history do not need to have additional immunization. Although literature review does not provide evidence of immunization being able to prevent disease after exposure to poliovirus [5], it has been reported that one-time polio vaccination for the immunized person boosts the immunization reaction and reduces the virus discharge from the intestine and pharynx of infected people [6]. Furthermore, in Australia, one time immunization was given to the contact regardless of past history when an imported polio case occurred in 2007 based on this report [7]. The 2012 NAP added one IPV (Inactivated Polio Vaccine) immunization to all contacts of the suspected case. If a person was vaccinated less than 1 month previously, he/she is exempt from one-time immunization, because the minimum immunization interval for the polio vaccine is 1 month. In the confirmed stage, the contacts should be given the necessary additional immunization (Table 5).

Discussion

Korea has not witnessed a patient infected with poliovirus since 1984, so it might be thought that poliomyelitis is an eliminated disease in Korea, but as in China [4] and Australia [6], it is a feasible scenario to have an incidence caused by an imported case and for this to turn out to be an outbreak.

Hence the Korea Centers Disease Control and Prevention made an NAP for imported polio in 2010, which was revised and systemized in 2012. The revised 2012 NAP has classified the suspect cases and confirmed cases, provides roles and countermeasures by agencies, and has provided specific classification and management items for contacts, so that the field workers can easily utilize the guidelines.

In the future, to enhance the ability of the field workers with these guidelines, we will continue to provide on-the-job education to them, and conduct research into polio immunity to provide evidence, which in turn may necessitate another revision.

References

• 1. World Health Organization Country Office Tajikistan, WHO Regional Office for Europe, European Centre for Disease Prevention and Control. Outbreak of poliomyelitis in Tajikistan in 2010: risk for importation and impact on polio surveillance in Europe? Euro Surveill 2010;15(17). pii = 19558Available from:http://www.eurosurveillance.org.
• 2. Korea Centers for Disease Control and Prevention. National infectious disease surveillance [Internet]. Available from:http://www.cdc.go.kr. 2011.
• 3. Song KM, Choe YJ, Cho H, et al. National Action Plan for response to poliovirus importation. Public Health Res Perspect 2011;2(1). 65−71.Article
• 4. Global Alert and Response (GAR). Wild poliovirus confirmed in China [Internet]. World Health Organization; Available from:http://www.who.int/csr/don/2011_09_01/en/index.html. 2011.
• 5. Australian Government Department of Health and Ageing. An acute flaccid paralysis and poliomyelitis response plan for Australia. Canberra (Australia): 2008.
• 6. Poliomyelitis prevention in the United States. Updated recommendations of the Advisory Committee on Immunization Practices. Morbid Mortal Wkly Rep MMWR 2000;49(RR-5). 1−22.PubMed
• 7. Carnie JA, Lester R, Moran R, et al. Public health response to imported case of poliomyelitis, Australia. Emerg Infect Dis [serial on the Internet] Available from:http://wwwnc.cdc.gov/eid/article/15/11/09-0027.htm. 2009 11.

Figure & Data

References

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