Evaluation of the Acute flaccid paralysis surveillance indicators in Zambia from 2015-2021: a retrospective analysis.

BACKGROUND: The resurgence of poliovirus infection in previously polio free regions and countries calls for renewed commitment to the global polio eradication efforts including strengthening of Acute Flaccid Paralysis (AFP) surveillance systems. Zambia is one of the countries substantially at risk for the importation of poliovirus infection from neighbouring countries including Malawi, Mozambique, and Democratic Republic of the Congo (DRC). This study describes a seven-year AFP surveillance, assesses the surveillance indicators, and highlights areas for improvement. METHODS: We conducted retrospective analysis of the routinely collected AFP surveillance data from January 2015 to December 2022. The AFP surveillance indicators performance was assessed using the World Health Organisation's recommended minimum AFP surveillance indicators performance. RESULTS: Cumulatively, a total of 1715 AFP cases were reported over the study period. More than half, 891 (52%) of reported cases were aged < 5 years with 917 (53.5%) of males. More than half, 1186 (69.2%) had fever at onset, 718 (41.9%) had asymmetric paralysis and 1164 (67.9%) had their paralysis progressed within 3 days of onset. The non-polio AFP rate ranges from 3.4 to 6.4 per 100,000 children < 15 years old and stool adequacy ranging from 70.9% to 90.2% indicating sensitive surveillance with late detection of cases. The percentage of cases with early stool collection, timely transportation was above the World Health Organisation (WHO) minimum of 80% but with declining proportion of stools arriving in the laboratory in optimal condition. Completeness of 60-days follow-up evaluation was suboptimal ranging from 0.9% to 28.2%. CONCLUSION: The AFP surveillance system in Zambia is doing well. However, additional efforts are needed to improve early detection of cases; stool sample collection, transportation and monitoring to ensure arrival in good condition in the laboratory; and improve 60-days follow-up evaluation for evidenced-based classification of inadequate AFP cases and proper care.

Evaluating the impact of COVID-19 on routine childhood immunizations coverage in Zambia.

There are growing concerns about the comeback of vaccine-preventable diseases. Epidemics exert shocks which affect other health performance indicators such as routine immunizations. Early model forecasts indicate decreased use of immunization services, which puts children at greater risk. Concerns about an increase in morbidity and mortality for illnesses other than COVID-19, particularly in children missing routine vaccinations, are of public health interest. In this study, we evaluate COVID-19 effects on the uptake of routine immunization in Zambia.This was an interrupted time series study. National data on routine immunization coverage between January 2017 and December 2022 were analyzed. Interrupted time series analysis was performed to quantify changes in immunization utilization. To determine if changes in the underlying patterns of utilization of immunization service were correlated with the commencement of COVID-19, seasonally adjusted segmented Poisson regression model was utilised.Utilization of health services was similar with historical levels prior to the first case of COVID-19. There was a significant drop in immunization coverage for measles dose two (RR, 0.59; 95% CI: 0.43-0.80). A decreased slope was observed in immunization coverage of Rotavirus dose one (RR, 0.97; 95% CI: 0.96-0.98) and Rotavirus dose two (RR, 0.97; 95% CI: 0.96-0.98). A growing slope was observed for Oral Poliovirus two (RR, 1.007; 95% CI: 1.004-1.011) and Oral Poliovirus three (RR, 1.007; 95% CI: 1.002-1011). We also observed a growing slope in BCG Bacille Calmette-Guerin (BCG) (RR, 1.001; 95% CI: 1.000-1011) and Pentavalent one (RR, 1.00; 95% CI: 1.001-1008) and three (RR, 1.004; 95% CI: 1.001-1008).The COVID-19 pandemic has had a number of unintended consequences that have affected the use of immunization services. Ensuring continuity in the provision of health services, especially childhood immunization, during pandemics or epidemics is crucial. Therefore, Investing in robust healthcare infrastructure to withstand surges, training and retaining a skilled workforce capable of handling emergencies and routine services simultaneously is very cardinal to avoid vaccine-preventable diseases, causing long-term health effects especially child mortality.

Detection of Human Adenovirus and Rotavirus in Wastewater in Lusaka, Zambia: Demonstrating the Utility of Environmental Surveillance for the Community.

Enteric infections due to viral pathogens are a major public health concern. Detecting the risk areas requires a strong surveillance system for pathogenic viruses in sources such as wastewater. Towards building an environmental surveillance system in Zambia, we aimed to identify group A rotavirus (RVA) and human adenovirus (HAdV) in wastewater. Convenient sampling was conducted at four study sites every Tuesday for five consecutive weeks. The research team focused on three different methods of viral concentration to determine the suitability in terms of cost and applicability for a regular surveillance system: the bag-mediated filtration system (BMFS), polyethylene glycol-based (PEG) precipitation, and skimmed milk (SM) flocculation. We screened 20 wastewater samples for HAdV and RVA using quantitative polymerase chain reaction (qPCR) and conventional polymerase chain reaction (cPCR). Of the 20 samples tested using qPCR, 18/20 (90%) tested positive for HAdV and 14/20 (70%) tested positive for RVA. For the genetic sequencing, qPCR positives were subjected to cPCR, of which 12 positives were successfully amplified. The human adenovirus was identified with a nucleotide identity range of 98.48% to 99.53% compared with the reference genome from GenBank. The BMFS and SM flocculation were the most consistent viral concentration methods for HAdV and RVA, respectively. A statistical analysis of the positives showed that viral positivity differed by site (p < 0.001). SM and PEG may be the most appropriate options in resource-limited settings such as Zambia due to the lower costs associated with these concentration methods. The demonstration of HAdV and RVA detection in wastewater suggests the presence of the pathogens in the communities under study and the need to establish a routine wastewater surveillance system for the identification of pathogens.