Adapting Nepal’s polio eradication programme

Abstract Problem Many countries have weak disease surveillance and immunization systems. The elimination of polio creates an opportunity to use staff and assets from the polio eradication programme to control other vaccine-preventable diseases and improve disease surveillance and immunization systems. Approach In 2003, the active surveillance system of Nepal’s polio eradication programme began to report on measles and neonatal tetanus cases. Japanese encephalitis and rubella cases were added to the surveillance system in 2004. Staff from the programme aided the development and implementation of government immunization policies, helped launch vaccination campaigns, and trained government staff in reporting practices and vaccine management. Local setting Nepal eliminated indigenous polio in 2000, and controlled outbreaks caused by polio importations between 2005 and 2010. Relevant changes In 2014, the surveillance activities had expanded to 299 sites, with active surveillance for measles, rubella and neonatal tetanus, including weekly visits from 15 surveillance medical officers. Sentinel surveillance for Japanese encephalitis consisted of 132 sites. Since 2002, staff from the eradication programme have helped to introduce six new vaccines and helped to secure funding from Gavi, the Vaccine Alliance. Staff have also assisted in responding to other health events in the country. Lesson learnt By expanding the activities of its polio eradication programme, Nepal has improved its surveillance and immunization systems and increased vaccination coverage of other vaccine-preventable diseases. Continued donor support, a close collaboration with the Expanded Programme on Immunization, and the retention of the polio eradication programme’s skilled workforce were important for this expansion.


Introduction
National immunization systems are important for reducing vaccine preventable diseases. 1 However, in many resourceconstrained countries, such systems need to be improved. This paper describes how Nepal's polio eradication programme expanded its work to aid efforts to control other vaccinediseases and improve Nepal's disease surveillance and immunization systems.

Local setting
Nepal eliminated indigenous polio in 2000 and controlled outbreaks caused by polio importations between 2005 and 2010. The country participated in the certification of wild poliovirus elimination in the World Health Organization (WHO) South-East Asia Region in 2014. 2 Nepal's polio eradication programme, created in 1998, is funded by the Global Polio Eradication Initiative and is affiliated with WHO's Nepal country office. The original aim of the programme was to conduct active surveillance for possible polio cases and to provide technical assistance and support on polio vaccination to the country's Expanded Programme on Immunization (EPI), which is the national immunization programme. In 2002, the polio eradication programme had 14 field-office based surveillance medical officers, who actively searched for people with acute flaccid paralysis (AFP), i.e. suspected polio cases. 3 The programme used these surveillance data to guide polio immunization activities, especially mass campaigns with oral poliovirus vaccine.
Nepal's EPI began as a pilot project in three districts in 1979, and by 1988 had expanded into a nationwide immunization system providing Bacillus Calmette-Guérin, diphtheriatetanus-pertussis, polio, tetanus and measles vaccines. 4,5 In 2000, EPI was obtaining information on vaccine-preventable disease cases, except polio, mainly from Nepal's health management information system. This information system collects reports of infectious disease cases from all government health facilities in Nepal, 4,5 but like many other passive surveillance systems, it has problems with underreporting, delayed reporting or incomplete reporting. 4,5 Lessons from the field Addressing vaccine-preventable diseases in Nepal Krishna P Paudel et al.
samples were collected and sent to the appropriate laboratories, and trained and motivated health workers regarding the identification, documentation, and reporting of new preventable disease cases. Blood samples were collected for measles confirmatory testing during investigations of suspected measles outbreaks. In 2004, the surveillance system expanded to include rubella, acute encephalitis syndrome and Japanese encephalitis. [5][6][7] Due to the similarity in clinical presentation between rubella and measles, surveillance for rubella began by testing for rubella immunoglobulin (Ig) M in blood samples from suspected measles cases that tested negative for measles IgM. 5 To detect acute encephalitis syndrome cases, a system of 45 sentinel medical facilities, located primarily in districts suspected to have the highest Japanese encephalitis risk, was established through a joint effort of the polio eradication programme, the Government of Nepal and several domestic and international laboratories and technical agencies. This sentinel system used the same database and reverse cold chain for shipping laboratory samples as the AFP surveillance system. Laboratory testing of blood or cerebrospinal fluid samples confirmed Japanese encephalitis cases. 6,7 Since 2002, the staff from the eradication programme have used their experience to help improve multiple aspects of EPI. They have provided continuous training and support to EPI staff on issues such as vaccine cold chain management, data management, and assessment of adverse events. They aided the development and implementation of policy guidelines. They have also assisted in supervising and monitoring routine immunization activities; assisted in microplanning to reach every district; enhanced research and grant writing capabilities; and piloted innovations, such as electronic immunization records and immunization training centres.

Relevant changes Surveillance
In 2014, the surveillance system activities had expanded to 299 sites, with active surveillance for measles, rubella and neonatal tetanus, including weekly visits from 15 surveillance medical officers. The sentinel system for acute encephalitis syndrome consisted of 132 sites. Information from the expanded surveillance has helped to guide the development and implementation of immunization policies. For example, in 2003, the surveillance system detected 1536 confirmed measles cases, which indicated the need of a vaccination campaign for people younger than 15 years ( Fig. 1). 5 EPI acted on this information and with the help of the eradication programme launched a measles vaccination campaign in 2004-2005. Following the campaign, 45 confirmed measles cases were identified in 2006. 5 In 2008, an increase in measles cases, a total of 394 confirmed cases, prompted a follow-up vaccination campaign in 2008, targeting children aged 9 months to 4 years. 8 The detection of additional measles cases in 2011, along with several years of data indicating a substantial burden of rubella, led to a combined measles-rubella vaccination campaign in 2012-2013 targeting all children between the ages of 9 months and 14 years. Afterwards, EPI introduced rubella vaccine into the country's routine immunization schedule. Subsequently, the numbers of confirmed measles and

Measles Rubella
Note: Confirmed measles and rubella cases are suspected measles cases (generalized maculopapular rash and fever plus one of the following: cough, coryza or conjunctivitis) with either laboratory confirmation through measles or rubella immunoglobulin M testing or an epidemiological link to a measles or rubella outbreak with a laboratory-confirmed case.
Lessons from the field Addressing vaccine-preventable diseases in Nepal Krishna P Paudel et al.
rubella cases have fallen, with only 19 measles and 37 rubella cases in 2013 and 2014 combined. However, further efforts are needed to achieve the goal of eliminating measles in Nepal. 8 In 2005, the data from the surveillance system confirmed the finding from the health management information system that Nepal had met the criteria for the elimination of neonatal tetanus (< 1 case of neonatal tetanus per 1000 live births in every district). 4 The surveillance system has continued to monitor for any increase in neonatal tetanus cases.
The data from the surveillance system also aided the planning of Nepal's first Japanese encephalitis vaccination campaign in 2006, by identifying the high-risk districts. 6 After the campaign, surveillance data demonstrated an 84% drop (from 864 to 141) in Japanese encephalitis cases in these districts. 7 By 2011, EPI had completed Japanese encephalitis vaccination campaigns in 31 high-and moderate-risk districts and they had introduced the vaccine into routine immunization in those districts. In 2016, EPI included nationwide Japanese encephalitis vaccination in the routine immunization schedule.

Immunization system strengthening
Since 2002, staff from the eradication programme have helped EPI to introduce hepatitis B vaccine (2003), Haemophilus influenzae type b vaccine (2009), inactivated polio vaccine (2014) and pneumococcal conjugate vaccine (2015), in addition to rubella vaccine and Japanese encephalitis vaccine. For example, for the introduction of inactivated polio vaccine, staff from both programmes worked together on an application for support from Gavi, the Vaccine Alliance. They planned together how to roll out the vaccine, develop training materials, and supervise and monitor the introduction of the vaccine. In 2014, Nepal became the first country, among those receiving support from Gavi, to introduce this vaccine. 9 They also planned, organized and executed the replacement of trivalent inactivated oral polio vaccine with bivalent inactivated vaccine on 17 April 2016. By monitoring the replacement, they could confirm by 11 May 2016 that all trivalent oral polio vaccine had been removed from the country's vaccine storage sites and health facilities providing immunizations.
The staff from the eradication programme have assisted in the development of the Comprehensive multiyear plan 2068-2072 (2011-2016) 10 and the national plan of action on intensification of routine immunization.
Between 2001 and 2015, the eradication programme's work contributed to the increase in vaccination coverage among Nepalese children aged 12-23 months. WHO and the United Nations Children's Fund estimated that the proportion of children who received three doses of diphtheria-pertussis-tetanus containing vaccine rose from 72% to 91% and the estimated proportion who received one dose of measles vaccine rose from 71% to 85%. 11 The staff from the eradication programme have also assisted in responding to other health events, such as dengue fever and cholera outbreaks and natural disasters. Following the major earthquake and subsequent aftershocks in April 2015, the staff assisted in monitoring for potential disease outbreaks, assessed damage to health facilities and helped identify needs for disaster relief. 12

Discussion
The polio eradication programme in Nepal has transitioned from focusing solely on polio to working on preventing other vaccine-preventable diseases. This transition has shown how staff and assets from an eradication programme can both strengthen a country's immunization system and reduce disease incidence (Box 1). Several factors contributed to this successful transition, including the eradication programme's ability to collaborate with EPI, international technical agencies and donors; the level of support received from donors for the expanded activities; and the eradication programme's well-trained, highly capable and motivated staff. Nepal's immunization system has benefited from external assistance. For example, Gavi has funded 60-70% of the costs of vaccine purchases in the country. The total vaccine cost in 2014 was approximately 6.5 million United States dollars. The immunization system has also been strengthened by the January 2016 enactment of the national immunization law that requires that the government allocate adequate funding for immunizations and establishes a fund for collecting national private sector donations for support of EPI. 13 Other countries have also enlisted their polio eradication programmes in their work on other diseases. For example, in 2007, Bangladesh and India initiated surveillance of Japanese encephalitis with the aid of polio surveillance officers. 14 In Nigeria, polio staff and their organizational experience were used to quickly end an outbreak of Ebola virus disease in 2014. 15 The possibility that polio may be eradicated in the next few years suggests that staff and assets currently funded by the Global Polio Eradication Initiative may increasingly become available in other areas. Countries should carefully manage the transition from polio eradication to other immunization and public health priorities to ensure that they effectively use valuable experience and assets from the Global Polio Eradication Initiative after the initiative ends. 16

Box 1. Summary of main lessons learnt
• Programmes created specifically to eliminate polio can successfully expand their efforts to strengthen immunization systems' abilities to address other vaccine preventable diseases. • Expanding polio surveillance systems to detect other vaccine-preventable diseases can effectively guide subsequent efforts to improve immunization systems. • The elimination of polio in a country provides an opportunity to transition polio eradication staff, assets and experiences to other projects.
Lessons from the field
Lessons from the field Addressing vaccine-preventable diseases in Nepal Krishna P Paudel et al.