The recent detection of poliovirus in places where it hasn’t been found for years has demonstrated the need for improved eradication efforts by governments and partners across the globe. Eradicating a disease isn’t easy, particularly in areas with limited capacity for surveillance, early detection, and response. Improving the delay involves rethinking the approach.
In Zambia, there are no reported polio cases, however, there were three positive environmental samples collected last year, with the most recent one in December 2022. The circulating vaccine-derived poliovirus type 2 (cVDPV2) is thought to have spread from an ongoing outbreak in the neighboring Democratic Republic of Congo.
The Centre for Infectious Disease Research in Zambia (CIDRZ) is an independent, local, non-governmental health organization that has been an active government partner through the Ministry of Health (MoH) and other Ministries since 2001. CIDRZ, under the Primary Care – Health Systems Strengthening department, remain confident that they are making progress in achieving the goal of a polio-free Zambia. There are several reasons for this optimism.
CIDRZ has been working in collaboration with the Zambia National Public Institute (ZNPHI), MoH’s Expanded Program on Immunization (EPI), the World Health Organization (WHO), and other partners in implementing the Polio Laboratory Sample Transport program country-wide, primarily across six out of 10 provinces. The program aims to improve polio lab samples’ quality and timeliness with technical assistance from VillageReach. CIDRZ started implementation in November 2022 after conducting a national assessment of the polio specimen referral system (SRS) with VillageReach earlier in 2022.
The story of Copperbelt province
Copperbelt province is one of the provinces where improvement has been noted following implementation. The area has already recorded over 100% of the expected annual non-polio Acute Flaccid Paralysis (AFP) rate in the first and second quarters of 2023 (meaning that more samples are being collected from children and tested, which is a positive trend); and improved the polio environmental surveillance (ES) sample condition from 50% in November 2022 to 100% in April – May 2023. This relates to the sample quantity, temperature and time in transit.
To supplement AFP surveillance and increase the sensitivity of the surveillance system, the Copperbelt provincial health office’s surveillance officer Albert Mweemba said that environmental surveillance was introduced in 2018 to detect the transmission of poliovirus in areas undetected by AFP surveillance.
The Copperbelt provincial health office received support from CIDRZ to implement environmental and AFP surveillance activities in all districts and all sentinel sites within the province. To this end, CIDRZ has supported the transportation of AFP and ES samples to the University Teaching Hospital (UTH) virology laboratory in Lusaka; purchased specimen carriers for transportation; and purchased thermometers and other supplies to ensure cold chain (sample temperature) and infection prevention for staff (gloves, disinfectant, soap, face masks and shields). They have also supported training for district surveillance officers (DSOs) and stool runners (which they engaged in each district) on sample collection, transportation and cold chain.
Improving the quality of environmental surveillance samples
“The conditions under which samples are transported play a critical role in maintaining sample quality. At project inception, it was noted that ES sites did not have the recommended specimen carriers for transporting samples. As such, ordinary (domestic) cooler boxes were used to store samples during collection and transportation from the collection site to the laboratory,” Mr. Mweemba explains.
The March 2023 data review showed a decline in the condition of ES samples on arrival at the laboratory to 61% (from 100% recorded in January – February 2023); six out of the seven bad samples were from the Copperbelt province. A drop in performance for the same indicator was also recorded in December 2022 due to cold chain temperatures not being maintained between +2 and +8oC for some ES samples.
A follow-up with the supervisors revealed that the samples were not transported in the recommended specimen carriers and that the reverse cold chain was not maintained during transportation.
CIDRZ thus funded on-site mentorship with officers who collect ES samples to address the bottlenecks that led to the failure to maintain the cold chain. CIDRZ and the Government are now exploring the use of Remote Temperature Monitoring (RTM) devices to be piloted in June. Through the project, CIDRZ has also procured and distributed specimen carriers and thermometers for each of Zambia’s 11 approved sewer sites (6 in Copperbelt, 4 in Lusaka, and 1 in the Eastern province). Mweemba says: “This was done to ensure that samples were being transported in recommended specimen carriers that helps to maintain the reverse cold chain, preserve the quality and maintain the safety of the sample.”
Tackling the problem from all angles
The ES samples were previously being couriered by public bus transport, unaccompanied, which sometimes compromised sample quality due to delayed collection at the bus terminal upon arrival.
The ES sites further reported that before project inception, they experienced inconsistency in the availability of sample collection and packaging materials; and delayed reimbursement of transport costs and allowances. This led to non-adherence to the ES sample collection schedules across the sites. However, CIDRZ has been providing timely (immediate) reimbursements for ES sample collectors and transporters, and now samples are accompanied by an officer during transportation and delivery at the laboratory.
Furthermore, according to the provincial surveillance officer, the frequency of sample collection has increased in seven ES sites, from once monthly to twice; the country is considering increasing the number of ES sites from 11 to 17 by the end of 2023. Mweemba also recommends expanding ES sites to all provincial centers, especially in provinces close to the borders with countries that have recorded polio outbreaks. He believes this will assist in timely monitoring and detecting poliovirus in the country.
Looking ahead, Mweemba observes that all this momentum is driven by the power of collaboration when the government, partners, and communities unite around the shared goal of improving polio surveillance in the country.
Additionally, he observes that the deployment and use of remote temperature devices would assist the transporter in monitoring the sample temperature within the specimen carrier at any location and time. Apart from that, he recommends strengthening knowledge transfer among healthcare workers through training, mentorships, and technical support services (TSS) activities at all levels to improve the quality of samples submitted for testing and overall poliovirus detection in the country. He recommends that the project continues supporting the district surveillance officers with monthly talk time for sending short messaging service (SMS) of AFP results to health facility staff to strengthen results dissemination and feedback at health facility levels.