Insecurity, polio vaccination rates, and polio incidence in northwest Pakistan

Progress in Access and Oral Polio Vaccine Coverage Among Children Aged <5 Years in Polio Campaigns After the Political Change in Afghanistan

BACKGROUND

Warfare has long impeded vaccination programs in polio-endemic Afghanistan. We aimed to describe progress in access to children under 5, oral polio vaccine (OPV) coverage among children under 5 in nationwide polio campaigns, and polio surveillance performance indicators after the Islamic Republic of Afghanistan collapsed to Taliban forces in August 2021.

METHODS

Trends in the number of wild poliovirus type 1 (WPV1) and circulating vaccine-derived poliovirus type 2 (cVDPV2) cases and surveillance indicators from 2015 to 2023, and trends in the OPV coverage in the November 2020-June 2022 polio campaigns, were described.

RESULTS

From 2015 to mid-July 2020, 74 of 126 (58.7%) WPV1 cases were reported from inaccessible areas. In November 2020, 34.1% of target children under 5 were inaccessible; in November 2021 (the first postchange polio campaign), all were accessible. From November 2020, under-5 OPV coverage of 69.9% rose steadily to 99.9% in the May 2022 campaign. The number of cVDPV cases fell from 308 (2020) to zero (2022). June 2022's house-to-house OPV coverage was 34.2% higher than non-house-to-house modalities. Nonpolio acute flaccid paralysis and stool adequacy rates rose from 18.5/100 000 and 92.6% in 2020 to 24.3/100 000 and 94.4% in 2022, respectively.

CONCLUSIONS

Children's inaccessibility no longer vitiates polio eradication; polio surveillance systems are less likely to miss any poliovirus circulation.

Immunity to poliovirus in Afghanistan: A household sampling method for serological assessment based on geographical information systems

Afghanistan continues to experience challenges affecting polio eradication. Mass polio vaccination campaigns, which aim to protect children under the age of 5, are a key eradication strategy. To date, the polio program in Afghanistan has only employed facility-based seroprevalence surveys, which can be subject to sampling bias. We describe the feasibility in implementing a cross-sectional household poliovirus seroprevalence survey based on geographical information systems (GIS) in three districts. Digital maps with randomly selected predetermined starting points were provided to teams, with a total target of 1,632 households. Teams were instructed to navigate to predetermined starting points and enrol the closest household within 60 m. To assess effectiveness of these methods, we calculated percentages for total households enrolled with valid geocoordinates collected within the designated boundary, and whether the Euclidean distance of households were within 60 m of a predetermined starting point. A normalized difference vegetation index (NDVI) image ratio was conducted to further investigate variability in team performances. The study enrolled a total of 78% of the target sample with 52% of all households within 60 m of a pre-selected point and 79% within the designated cluster boundary. Success varied considerably between the four target areas ranging from 42% enrolment of the target sample in one place to 90% enrolment of the target sample in another. Interviews with the field teams revealed that differences in security status and amount of non-residential land cover were key barriers to higher enrolment rates. Our findings indicate household poliovirus seroprevalence surveys using GIS-based sampling can be effectively implemented in polio endemic countries to capture representative samples. We also proposed ways to achieve higher success rates if these methods are to be used in the future, particularly in areas with concerns of insecurity or spatially dispersed residential units.

Spatial analysis of genetic clusters and epidemiologic factors related to wild poliovirus type 1 persistence in Afghanistan and Pakistan

Following the certification of the World Health Organization Region of Africa as free of serotype 1 wild poliovirus (WPV1) in 2020, Afghanistan and Pakistan represent the last remaining WPV1 reservoirs. As efforts continue in these countries to progress to eradication, there is an opportunity for a deeper understanding of the spatiotemporal characteristics and epidemiological risk factors associated with continual WPV1 circulation in the region. Using poliovirus surveillance data from 2017-2019, we used pairwise comparisons of VP1 nucleotide sequences to illustrate the spatiotemporal WPV1 dispersal to identify key sources and destinations of potentially infected, highly mobile populations. We then predicted the odds of WPV1 detection at the district level using a generalized linear model with structural indicators of health, security, environment, and population demographics. We identified evidence of widespread population mobility based on WPV1 dispersal within and between the countries, and evidence indicating five districts in Afghanistan (Arghandab, Batikot, Bermel, Muhamandara and Nawzad) and four districts in Pakistan (Charsada, Dera Ismail Khan, Killa Abdullah and Khyber) act as cross-border WPV1 circulation reservoirs. We found that the probability of detecting WPV1 in a district increases with each armed conflict event (OR = 1·024, +- 0·008), level of food insecurity (OR = 1·531, +-0·179), and mean degrees Celsius during the months of greatest precipitation (OR = 1·079, +- 0·019). Our results highlight the multidisciplinary complexities contributing to the continued transmission of WPV1 in Afghanistan and Pakistan. We discuss the implications of our results, stressing the value of coordination during this final chapter of the wild polio virus eradication initiative.

Dynamic mapping of cholera outbreak during the Yemeni Civil War, 2016-2019

Widespread destruction from the Yemeni Civil War (2014-present) triggered the world's largest cholera outbreak. We compiled a comprehensive health dataset and created dynamic maps to demonstrate spatiotemporal changes in cholera infections and war conflicts. We aligned and merged daily, weekly, and monthly epidemiological bulletins of confirmed cholera infections and daily conflict events and fatality records to create a dataset of weekly time series for Yemen at the governorate level (subnational regions administered by governors) from 4 January 2016 through 29 December 2019. We demonstrated the use of dynamic mapping for tracing the onset and spread of infection and manmade factors that amplify the outbreak. We report curated data and visualization techniques to further uncover associations between infectious disease outbreaks and risk factors and to better coordinate humanitarian aid and relief efforts during complex emergencies.

Attitude and perception towards vaccination against poliomyelitis in Peshawar, Pakistan

OBJECTIVE:

This research aimed to quantitatively assess the general public's awareness, attitude and perception of polio and its vaccination in Peshawar KPK, Pakistan.

METHODS:

We conducted a survey-based study to understand the surge in polio cases from 2015 to 2019 in the Peshawar city of the Khyber Pakhtunkhwa (KPK), Pakistan. A pre-tested questionnaire-based study was conducted in 2019 to assess the attitude and general perception of residents of Peshawar KPK towards polio vaccination.

RESULTS:

Out of 241 country-wide polio cases, 63 (26.1%) polio cases were reported in Peshawar city from 2015–2019. The questionnaire revealed that individuals between 18–30 years of age had sufficient knowledge (65.1%) about polio. Male and female participants had equal awareness (~ 43%). Participants with higher education (45.9%), those with better financial status (49.5%), individuals with children < 5 years of age (46.4%), and those who had experience of a polio patient (63.1%) had better knowledge. Participants inhabiting the central city were better aware (50.5%) of polio than individuals living in the outskirts.

CONCLUSION:

The data indicated that poor knowledge and negative attitudes of people towards polio vaccination are the main causes of the polio eradication program's failure. Moreover, religious beliefs, unchecked migration between the Pak-Afghan border, and lack of knowledge about polio vaccination are identified as critical barriers to polio eradication.

Toward creating equity in access to COVID-19 vaccination for female population in Multan, Punjab, Pakistan

The researchers examined the access to the COVID-19 vaccine among 32 females in Multan, Punjab, Pakistan. The aim of the study is to access the independence of decision-making among female participants to vaccinate themselves against the COVID-19. Participants of the study belong to Multan, a city of Southern Punjab. The researchers adopt a qualitative research design, using in-depth interviews, repeated open-ended questions, and local languages. Among general conclusions of this study are, female dependence on male members to get the vaccination, limited control on deciding the need for vaccination, and patriarchal decision to vaccinate the family. The aim of the researchers is to contribute toward an effective COVID-19 vaccination campaign by minimizing discrimination against women in accessing the vaccine.

Effects of terrorist attacks on access to maternal healthcare services: a national longitudinal study in Burkina Faso

INTRODUCTION

Most of the literature on terrorist attacks' health impacts has focused on direct victims rather than on distal consequences in the overall population. There is limited knowledge on how terrorist attacks can be detrimental to access to healthcare services. The objective of this study is to assess the impact of terrorist attacks on the utilisation of maternal healthcare services by examining the case of Burkina Faso.

METHODS

This longitudinal quasi-experimental study uses multiple interrupted time series analysis. Utilisation of healthcare services data was extracted from the National Health Information System in Burkina Faso. Data span the period of January 2013-December 2018 and include all public primary healthcare centres and district hospitals. Terrorist attack data were extracted from the Armed Conflict Location and Event Data project. Negative binomial regression models were fitted with fixed effects to isolate the immediate and long-term effects of terrorist attacks on three outcomes (antenatal care visits, of facility deliveries and of cesarean sections).

RESULTS

During the next month of an attack, the incidence of assisted deliveries in healthcare facilities is significantly reduced by 3.8% (95% CI 1.3 to 6.3). Multiple attacks have immediate effects more pronounced than single attacks. Longitudinal analysis show that the incremental number of terrorist attacks is associated with a decrease of the three outcomes. For every additional attack in a commune, the incidence of cesarean sections is reduced by 7.7% (95% CI 4.7 to 10.7) while, for assisted deliveries, it is reduced by 2.5% (95% CI 1.9 to 3.1) and, for antenatal care visits, by 1.8% (95% CI 1.2 to 2.5).

CONCLUSION

Terrorist attacks constitute a new barrier to access of maternal healthcare in Burkina Faso. The exponential increase in terrorist activities in West Africa is expected to have negative effects on maternal health in the entire region.

Genetic Epidemiology Reveals 3 Chronic Reservoir Areas With Recurrent Population Mobility Challenging Poliovirus Eradication in Pakistan

BACKGROUND

Pakistan is among 3 countries endemic for wild poliovirus type 1 (WPV1) circulation that are still struggling for eradication of poliomyelitis. Active clinical and environmental surveillance with meticulous laboratory investigations provide insights into poliovirus transmission patterns and genomic diversity to inform decisions for strategic operations required to achieve eradication.

METHODS

We analyzed epidemiological and virological data to comprehend the current epidemiological status of WPV1 in Pakistan during 2015-2017. Stool specimens of patients with acute flaccid paralysis (AFP) and sewage samples collected from 60 environmental sites were tested. Viral culturing, intratypic differentiation by real-time polymerase chain reaction, and nucleic acid sequencing of the VP1 region of the poliovirus genome to determine genetic relatedness among WPV1 strains were applied.

RESULTS

Poliovirus isolates were grouped into 11 distinct clusters, which had ≥95% nucleotide homology in the VP1 coding region. Most of the poliovirus burden was shared by 3 major reservoirs: Karachi, Peshawar, and Quetta block (64.2% in 2015, 75.4% in 2016, and 76.7% in 2017).

CONCLUSIONS

Environmental surveillance reveals importations and pockets of unimmunized children that dictate intensive target mop-up campaigns to contain poliovirus transmission. A decrease in the number of orphan isolates reflects effective combination of AFP and environmental surveillance in Pakistan. The genetic data reflect sustained transmission within reservoir areas, further expanded by periodic importations to areas of high immunity reflected by immediate termination of imported viruses. Improved immunization coverage with high-quality surveillance is vital for global certification of polio eradication.

Disease Surveillance Investments and Administration: Limits to Information Value in Pakistan Polio Eradication

In Pakistan, annual poliovirus investment decisions drive quantities of supplemental immunization campaigns districts receive. In this article, we assess whether increased spending on poliovirus surveillance is associated with greater likelihood of correctly identifying districts at high risk of polio with assignment of an elevated "risk ranking." We reviewed programmatic documents from Pakistan for the period from 2012-2017, recording whether districts had been classified as "high risk" or "low risk" in each year. Through document review, we developed a decision tree to describe the ranking decisions. Then, integrating data from the World Health Organization and Global Polio Eradication Initiative, we constructed a Bayesian decision network reflecting investments in polio surveillance and immunization campaigns, surveillance metrics, disease incidence, immunization rates, and occurrence of polio cases. We test these factors for statistical association with the outcome of interest-a change in risk rank between the beginning and the end of the one-year time period. We simulate different spending scenarios and predict their impact on district risk ranking in future time periods. We find that per district spending increases are associated with increased identification of cases of acute flaccid paralysis (AFP). However, the low specificity of AFP investment and the largely invariant ranking of district risk means that even large increases in surveillance spending are unlikely to promote major changes in risk rankings at the current stage of the Pakistan polio eradication campaign.

Prevalence of Parental refusal rate and its associated factors in routine immunization by using WHO Vaccine Hesitancy tool: A Cross sectional study at district Bannu, KP, Pakistan

OBJECTIVE

To determine the vaccination refusal rate, associated factors and perceptions of parents who refused routine immunization for their children using the World Health Organization (WHO) SAGE Working Group on Vaccine Hesitancy Survey Tool.

MATERIALS AND METHODS

A cross-sectional survey was conducted using multi-stage cluster sampling in Bannu District, Khyber Pakhtunkhwa Province, Pakistan from March 2019 to July 2019. A WHO validated questionaire was used. The outcome variable was parental refusal of routine immunization of their children. Logistic regression was performed for associations, and multi-regression was applied to identify any confounders.

RESULTS

Of 610 parents, 170 (27.9%) refused vaccination of their children. Of these, the majority of mothers had no education [n = 145 (85.3%); p = 0.03], and mothers were less likely to own a mobile phone than fathers [24 (14.1%) vs 152 (89.4%); p ≤ 0.001]. The vaccination refusal rate was higher in parents with food security [n = 88 (51.8%)] compared with parents with minimal food insecurity [n = 62 (36.5%)] and high food insecurity [20 (11.8%); p ≤ 0.05)]. On multi-variate logistic regression, fathers who were employed [adjusted odds ratio (OR) 0.59, 95% confidence interval (CI) 0.37-0.94; p = 0.02] and had a high level of education (adjusted OR 0.21, 95% CI 0.08-0.50; p ≤ 0.001) were less likely to refuse vaccination of their children. Parents with high food insecurity were more likely to refuse vaccination of their children (adjusted OR 2.2, 95% CI 1.0-0.50; p = 0.04) compared with parents with minimal food insecurity (adjusted OR 1.6, 95% CI 1.0-2.5; p = 0.02).

CONCLUSION

The vaccination refusal rate was very high among parents, and this was associated with inability to read or write, no education, owning a mobile phone, unemployment and food security.

Prosocial polio vaccination in Israel

Regions with insufficient vaccination have hindered worldwide poliomyelitis eradication, as they are vulnerable to sporadic outbreaks through reintroduction of the disease. Despite Israel's having been declared polio-free in 1988, a routine sewage surveillance program detected polio in 2013. To curtail transmission, the Israel Ministry of Health launched a vaccine campaign to vaccinate children-who had only received the inactivated polio vaccine-with the oral polio vaccine (OPV). Determining the degree of prosocial motivation in vaccination behavior is challenging because vaccination typically provides direct benefits to the individual as well as indirect benefits to the community by curtailing transmission. However, the Israel OPV campaign provides a unique and excellent opportunity to quantify and model prosocial vaccination as its primary objective was to avert transmission. Using primary survey data and a game-theoretical model, we examine and quantify prosocial behavior during the OPV campaign. We found that the observed vaccination behavior in the Israeli OPV campaign is attributable to prosocial behavior and heterogeneous perceived risk of paralysis based on the individual's comprehension of the prosocial nature of the campaign. We also found that the benefit of increasing comprehension of the prosocial nature of the campaign would be limited if even 24% of the population acts primarily from self-interest, as greater vaccination coverage provides no personal utility to them. Our results suggest that to improve coverage, communication efforts should also focus on alleviating perceived fears surrounding the vaccine.

Polio vaccination campaign in Pakistan: a step towards eradication or still a challenge in hand?

Polio is an acute viral disease that is still endemic in Pakistan. The polio vaccination program is facing many challenges that result in an increased number of new cases. The success of polio vaccination has been threatened in different parts of Pakistan. In the past, the immunization program was affected by different factors including insecurity, inducing mass migration and displacement, life threats to polio workers, and restricted access to the vulnerable population. Misconceptions and misunderstanding about the polio vaccine are a major obstacle in polio eradication which need to be erased by organized effects of increasing vaccine awareness.

Poliovirus serotype 2 and coxsackievirus A promote the natural recombination of poliovirus

Poliovirus (PV) is a member of the species Enterovirus C (EV-C), which may cause irreversible paralysis and death. So, for the purpose of analyzing the evolution of PV2 to help in eradicating PVs globally, a recombination analysis was performed to verify all viral genomes of EV-C, and we found 13 putative recombination events that produced PV1, 14 recombination events that can give rise to PV2, and 9 events that can lead to PV3. By analyzing our findings, we found that PV2 was involved in 25 of 36 PV recombination events, whereas coxsackievirus A (CVA) strains were involved in 12 of 36 PV recombination events, indicating that PV2 and CVAs play major roles in the natural recombination of PV. In addition, we found 11 of 36 breakpoint positions located in 2A region, which is the most active region of the recombination events.

The exacerbation of Ebola outbreaks by conflict in the Democratic Republic of the Congo

The interplay between civil unrest and disease transmission is not well understood. Violence targeting healthcare workers and Ebola treatment centers in the Democratic Republic of the Congo (DRC) has been thwarting the case isolation, treatment, and vaccination efforts. The extent to which conflict impedes public health response and contributes to incidence has not previously been evaluated. We construct a timeline of conflict events throughout the course of the epidemic and provide an ethnographic appraisal of the local conditions that preceded and followed conflict events. Informed by temporal incidence and conflict data as well as the ethnographic evidence, we developed a model of Ebola transmission and control to assess the impact of conflict on the epidemic in the eastern DRC from April 30, 2018, to June 23, 2019. We found that both the rapidity of case isolation and the population-level effectiveness of vaccination varied notably as a result of preceding unrest and subsequent impact of conflict events. Furthermore, conflict events were found to reverse an otherwise declining phase of the epidemic trajectory. Our model framework can be extended to other infectious diseases in the same and other regions of the world experiencing conflict and violence.