It takes more than a town crier reading a scroll to shut down a polio outbreak in any country.
Rather, multidisciplinary teams of experts are needed to analyze data at the national level from polio eradication programs, often more than once.
They examine evidence, crunch numbers to analyze information, and interview health workers, polio teams, and high-level authorities, among other activities, before reaching a conclusion.
The recent poliovirus outbreak in Sudan The outbreak of circulating vaccine-derived poliovirus (cVDPV) type 2 in Sudan began with importation of the virus from neighboring Chad. Confirmed in August 2020, the outbreak affected and paralyzed 58 children in 42 districts in 15 states.
Additionally, 14 sewage samples in Khartoum tested positive for cVDPV2, indicating circulation there.
Mounting a robust response to the outbreak, Sudan carried out 2 high-quality national campaigns to administer monovalent oral polio vaccine type 2 (mOPV2) to children in all 18 states and 184 localities in November 2020 and January 2021.
Who Makes the Decisions On October 7, 2021, a virtual technical assessment mission began the process of testing for poliovirus freedom throughout Sudan.
Members of the assessment group shared recommendations with the Sudanese polio eradication team to scale up their efforts across the country.
Then, from July 24 to August 1, 2022, an official outbreak response assessment team undertook a second phase of this detailed task, visiting Khartoum and 6 of Sudan’s 18 states as part of their work.
Both review teams were composed of experts from WHO and the United Nations Children’s Fund (UNICEF) with skills and experience in global public health, epidemiology and biostatistics, surveillance, vaccine management, and communication.
They worked closely with the Sudanese Federal Ministry of Health, with ministry staff at the state level, and with health workers at ground level.
Attention to polio surveillance In particular, a review of the surveillance system is important to close any outbreak of disease.
Based on this, the evaluation team analyzed the functionality and sensitivity of the polio surveillance system in Sudan to ensure that no case of polio was missed.
They noted that Sudan’s acute flaccid paralysis (AFP) surveillance indicators meet the required indicators, and that the 14 environmental monitoring sites across Sudan are collecting and testing samples regularly and in accordance with international protocols.
Following standard protocols, the team in Sudan collects stool samples from both healthy children and children with AFP.
A review of the data showed that all samples collected since December 18, 2020, the date of paralysis onset of the last child affected by the outbreak, were processed like clockwork in the laboratory in Sudan, were reported as poliovirus negative.
and they registered.
Speaking about the role of surveillance in this process, Dr. Hamid Jafari, WHO Director for Polio Eradication in the Eastern Mediterranean Region, said: “The program must be extremely diligent and careful before declaring that a The outbreak is over.
The most important element driving that decision is the quality of surveillance — the country’s ability to detect any remaining circulating poliovirus.”
Holistic summary of all technical work The technical mission also reviewed the core functions of Sudan’s laboratories, the country’s preparedness mechanisms for poliovirus events or outbreaks, data on population immunity and childhood immunization, and vaccine management protocol.
After this extensive work, the outbreak team concluded that the spread of cVDPV2 had stopped and the outbreak was over.
“The credits go to public health officers and immunization staff on the ground.
A rapid and well-planned response improved immunity among children and contained this outbreak in the first few months after the declaration.
Even though this outbreak is over, we have received enough recommendations to maintain sensitive AFP surveillance, ensure better preparedness and response, improve essential immunization coverage, and strengthen cross-border coordination,” said Dr. Ni’ma Saeed Abid, WHO Representative.
Briefing the Government of Sudan and its partners, the mission reiterated that Sudan remains at high risk of poliovirus and that the current robust level of functionality and preparedness must be maintained to rapidly detect and respond to any future emergence or importation of poliovirus.