A new year with no measles cases
by Pieter JM Van Maaren
The year 2012 ends on a positive note for Cambodia. The country is moving closer to the nationwide elimination of measles with the National Immunization Program reporting zero cases for a full 12 months as of December 2012. This is a dramatic reduction from 2011 when over 700 cases of measles in children were reported and 2008 when there were over 1 800 cases. The last laboratory confirmed case of measles was reported from Kampong Speu Province in November 2011.
This news is indeed encouraging. By all accounts it indicates that at the start of 2013, Cambodia is on the path of becoming a measles-free country together with every other country in the Western Pacific Region. In 2003, the World Health Organization's Regional Office for the Western Pacific (WHO/WPRO) nominated 2012 as the target date for measles elimination, defined as the absence of transmission of endemic measles virus.
Measles is one of the most infectious viruses known to humans. It can cause serious illness and complications, particularly in infants and children, including pneumonia, diarrhoea and blindness. Cambodia's gains towards achieving measles elimination is due to intensified nationwide vaccination efforts to ensure the termination of wild virus circulation and improving disease surveillance systems.
As with other countries that have declared elimination of measles, Cambodia's national elimination plan includes a high two-dose measles immunization coverage and a disease surveillance system capable of a rapid response to potential measles outbreaks.
Cambodia’s measles control efforts started in 1986 with the introduction of the first dose of measles vaccine for all infants at nine months of age, sparking the first step to a dramatic change. Progressive higher coverage with the first dose was accelerated with nationwide measles immunization campaigns in 2001–2003, 2007 and 2011 conducted by the National Immunization Program. These nationwide immunization campaigns received support from the Royal Government's contributions, Cambodia's health partners led by the World Health Organization, United Nations Children’s Fund (UNICEF), Australian Agency for Internal Development (AusAID), Japan International Cooperation Agency (JICA) and Latter Day Saints Charities, and the Second Health Sector Support Project (HSSP2) pool fund partners.
From 2012, the National Immunization Program introduced a new 18 months dose of measles vaccine to further strengthen efforts to ensure the highest protection against measles. All children under two years of age will now receive two doses of measles vaccine, the first at nine months of age, the second at 18 months. Countries providing two opportunities for measles vaccination have experienced dramatic declines in the number of cases and even greater reductions in the number of deaths.
Without doubt, the close involvement of Cambodia's health partners, civil society, community leaders, health centre staff and village health volunteers under the umbrella of leadership provided by the Ministry of Health was vital for the success of the measles immunization campaigns. This multi-sectoral involvement is important in identifying and vaccinating infants and children in high risk communities who often miss their routine dose of measles vaccine. The close collaboration and effective integration of the expanded immunization program with the health system also ensured all infants and children in these communities received full vaccination.
Overall, Cambodia's measles elimination efforts have borne fruit due to the experiences of the 1990’s when the country got rid of polio forever. Cambodia's polio eradication measures included both national immunization days and an intensive house-to-house immunization campaign. The efforts paid off and the last case of wild poliovirus in Cambodia was in March 1997, which was also the last case in the Western Pacific Region.
The good grass root level planning, commitment of health workers, efficient vaccine delivery in mass immunization campaigns, good social mobilization, public support and strong political will now provide a strong platform for the Ministry of Health to introduce additional vaccines, such as the rubella vaccine in 2013.
Rubella, a disease caused by the rubella virus, can cause congenital rubella syndrome (CRS) in the newly born. CRS is the main reason a vaccine for rubella was developed. Many mothers who contract rubella within the first critical trimester either have a miscarriage or a still born baby. If the baby survives the infection, it can be born with severe heart disorders, blindness, deafness, or other life threatening organ disorders.
Relying on Cambodia's strengths of polio eradication and successful measles elimination efforts, the start of a rubella mass immunization campaign in the later part of 2013 will be the most pragmatic approach to control rubella and eliminate CRS in the shortest possible time.
It is indeed a tremendous achievement to be able to say that Cambodia is free from measles. The challenge now is for Cambodia to maintain its achievement of having no measles cases for another two years, so that the country can be certified by the World Health Organization as having eliminated measles. This will now require a strong focus on routine immunization activities and ensuring especially that they reach the most marginalized communities, namely the urban and rural poor, ethnic and minority populations, with two doses of measles vaccine before every child’s 2nd birthday.
High levels of vaccination would continue to be needed in order to prevent reintroduction of the virus from other areas and vaccination can only be ceased when measles is eradicated with the interruption of measles transmission globally.
Nonetheless, Cambodia is on the right track and the World Health Organization is confident that the country will be certified measles-free by 2014.
Dr. Pieter JM Van Maaren is the World Health Organization’s Representative in Cambodia.