Description of the AFP surveillance system in Sokoto state

The mode of operation of the Sokoto state AFP surveillance system is similar to the other 35 states and the Federal Capital Territory, and it is part of the broader AFP surveillance system in Nigeria (Fig. 1). In the surveillance system, an AFP case is defined as “Any child under 15 years of age with the acute (sudden) onset of weakness or floppiness of one or more limbs or any person of any age with paralytic illness in whom a clinician suspects poliomyelitis” [17].

Flow chart of AFP surveillance system. CIF - Case Investigation Form, DSNO - Disease Surveillance and Notification Officer, FMoH - Federal Ministry of Health, NPHCDA - National Primary Health Care Development Agency, NIO - National Immunization Officer, NPEC: National Polio Expert Review Committee, SE: State Epidemiologist, WHO SO - World Health Organization Surveillance Officer

The primary purpose of the AFP surveillance system in Sokoto state is to detect and document the presence or absence of WPV. The objectives of the AFP surveillance system in Sokoto state include:

To provide data-driven evidence that guides the advancement of strategies that lead to polio eradication.

To identify areas of cVDPV in Sokoto state.

To investigate all detected AFP cases and demonstrate the non-transmission of WPV in Sokoto state.

To assess the effect of Routine Immunization Activities (RIAs) and Supplementary Immunization Activities (SIAs) against polio.

The flow of data in the AFP surveillance in Sokoto state begins with the notification of every case by community informants (such as traditional bone setters) or the health facility focal persons to their respective LGA Disease Surveillance and Notification Officers (DSNOs). The DSNOs are responsible for ensuring that adequate stool samples are collected from suspected cases. They are also responsible for ensuring that the samples get to the national polio laboratory in Ibadan, Oyo state in optimal temperature accompanied with correctly filled AFP Case Investigation Forms (CIFs). The LGA DSNO is responsible for giving regular feedback to the reporting facilities, focal persons and communities.

The state epidemiologist and the state DSNO facilitate and oversee the activities of the LGA DSNO. The WHO cluster consultants assigned to different LGAs are responsible for verifying the suspected cases and conducting 60-day follow-up for all AFP cases. The state epidemiologist gives feedback to the LGAs and reports to the Nigeria Center for Disease Control (NCDC), National Primary Health Care Development Agency (NPHCDA), Federal Ministry of Health (FMoH); and the state DSNO gives feedback to the LGAs on laboratory results (Fig. ​(Fig.11).

The funding of the AFP surveillance System in Sokoto State is by the federal government, Sokoto state government, and LGAs with robust technical and financial support by development partners notably, WHO and Centers for Disease Control and Prevention (CDC) / Africa Field Epidemiology Network (AFENET). WHO sponsors the active case finding visits by DSNOs to AFP reporting sites. Additionally, the organization supports the DSNOs with transportation allowances to attend the monthly surveillance meetings at the states’ capital. CDC/AFENET provides technical and human resource support to all the LGAs to complement Government resources.