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The number of wild poliovirus (WPV) cases in Nigeria decreased from 1,122 in 2006 to six WPV type 1 (WPV1) in 2014 (1). During August 2014-July 2016, no WPV cases were detected; during August-September 2016, four cases were reported in Borno State. An insurgency in northeastern Nigeria had resulted in 468,800 children aged <5 years deprived of health services in Borno by 2016. Military activities in mid-2016 freed isolated families to travel to camps, where the four WPV1 cases were detected. Oral poliovirus vaccine (OPV) campaigns were intensified during August 2016-December 2017; since October 2016, no WPV has been detected (2). Vaccination activities in insurgent-held areas are conducted by security forces; however, 60,000 unvaccinated children remain in unreached settlements. Since 2018, circulating vaccine-derived poliovirus type 2 (cVDPV2) has emerged and spread from Nigeria to Niger and Cameroon; outbreak responses to date have not interrupted transmission. This report describes progress in Nigeria polio eradication activities during January 2018-May 2019 and updates the previous report (2). Interruption of cVDPV2 transmission in Nigeria will need increased efforts to improve campaign quality and include insurgent-held areas. Progress in surveillance and immunization activities will continue to be reviewed, potentially allowing certification of interruption of WPV transmission in Africa in 2020. [ABSTRACT FROM AUTHOR]

Nearly three decades after the World Health Assembly launched the Global Polio Eradication Initiative in 1988, four of the six World Health Organization (WHO) regions have been certified polio-free (1). Nigeria is one of three countries, including Pakistan and Afghanistan, where wild poliovirus (WPV) transmission has never been interrupted. In September 2015, after >1 year without any reported WPV cases, Nigeria was removed from WHO's list of countries with endemic WPV transmission (2); however, during August and September 2016, four type 1 WPV (WPV1) cases were reported from Borno State, a state in northeastern Nigeria experiencing a violent insurgency (3). The Nigerian government, in collaboration with partners, launched a large-scale coordinated response to the outbreak (3). This report describes progress in polio eradication activities in Nigeria during January-December 2017 and updates previous reports (3-5). No WPV cases have been reported in Nigeria since September 2016; the latest case had onset of paralysis on August 21, 2016 (3). However, polio surveillance has not been feasible in insurgent-controlled areas of Borno State. Implementation of new strategies has helped mitigate the challenges of reaching and vaccinating children living in security-compromised areas, and other strategies are planned. Despite these initiatives, however, approximately 130,000-210,000 (28%-45%) of the estimated 469,000 eligible children living in inaccessible areas in 2016 have not been vaccinated. Sustained efforts to optimize surveillance and improve immunization coverage, especially among children in inaccessible areas, are needed. [ABSTRACT FROM AUTHOR]

What is already known on this topic? Nigeria is one of only three countries in the world where wild poliovirus (WPV) transmission has never been interrupted. Nigeria's 2012 national polio eradication emergency plan has led to improved quality of vaccination efforts, increased accountability, and a decline in WPV cases from 2013 to 2014. What is added by this report? The number of WPV cases decreased from six during 2014 to zero through July 2015. Only one reported case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been reported to date in 2015; however, the number of reported cVDPV2 cases increased from 2013 to 2014. Although genetic diversity declined during 2012–2014 and surveillance performance indicators have been met, gaps in surveillance persist. What are the implications for public health practice? Challenges include maintaining political support and program funding in the absence of active WPV transmission, maintaining high levels of population immunity in hard-to-reach areas, and accessing children in security-compromised parts of the northeastern states. Pending the clearance of the 218 remaining laboratory results, Nigeria is poised to be removed from the World Health Organization's list of polio-endemic countries in September 2015. When this occurs, certification of a polio-free Africa region by the end of 2017 will be achievable. Documenting lessons learned during this fight for polio eradication will allow Nigeria to successfully use existing infrastructure to address other public health problems. [ABSTRACT FROM AUTHOR]

The article reports on the progress of polio eradication efforts worldwide from 2014-15. Data provided highlights the supplementary immunization activities (SIA) in 45 countries in 2014, surveillance for cases of acute flaccid paralysis (AFP) among children, and the total wild poliovirus (WPV) cases reported during 2014. The efforts to eliminate poliovirus transmission in African countries including Nigeria and the challenges to polio eradication program in Pakistan are discussed.

The article highlights developments in the management of poliomyelitis in Nigeria from January 2013 to September 2014. Topics discussed include the routine vaccination of infants and children with trivalent oral polio vaccine, improvement in supplemental immunization activities (SIA), implementation of innovations to address insecurity challenges such as the use of permanent health teams, poliovirus surveillance, incidence of wild poliovirus, and genomic sequence analysis.

The article focuses on the progress toward polio eradication in 2013-2014. Topics discussed include routine vaccination coverage, supplementary immunization activities and poliovirus surveillance. Also mentioned are the wild poliovirus cases reported in countries like Afghanistan, Nigeria and Pakistan and the issuance of temporary recommendations to reduce international exportation of poliovirus.

The article summarizes polio eradication activities in Nigeria from January 2012 to September 2013 and provides updates on previous reports. It is said that, in 2013, no polio cases of any type have been detected in the northwest of Nigeria for the first time ever. It is noted that the country's polio eradication program suffered setbacks in February 2013. Nigeria's environmental surveillance was expanded from three venues in 2011 in Kano to 19 sites in 2013.

The Global Polio Eradication Initiative uses an outbreak response protocol that defines type 2 Sabin or Sabin-like virus as those with 0–5 nucleotides diverging from their parental strain in the complete VP1 genomic region. Sabin or Sabin-like viruses share highly similar genome sequences, regardless of their origin. Thus, it is challenging to distinguish viruses at a higher resolution to detect polio clusters or trace sources for local transmissions of viruses at an early stage. To identify type 2 Sabin or Sabin-like sources and improve our ability to map viral sources to campaigns during the polio endgame, we investigated the feasibility of a new method for genetic sequence analysis. We named the method Major Minor Variation Clustering (MMVC), which uses a network model to simultaneously incorporate sequence similarity in major and minor variants in addition to onset dates to detect fine-scale polio clusters. Each identified cluster represents a collection of sequences that are highly similar in both major and minor variants, enabling the discovery of new links between viruses. By applying the method to a published data set collected in Nigeria during 2009–2012, we found that clusters identified using this method have several improvements over clusters derived from a phylogenetic tree approach. Integrative data analysis reveals that sequences in the same cluster have greater genomic similarities and better agreement with onset dates. As a complement to current phylogenetic tree approaches, MMVC has the potential to improve epidemiological surveillance and investigation precision to guide polio eradication. [ABSTRACT FROM AUTHOR]

To assess the dynamics of genetic reversion of live poliovirus vaccine in humans, we studied molecular evolution in Sabin-like poliovirus isolates from Nigerian acute flaccid paralysis cases obtained from routine surveillance. We employed a novel modeling approach to infer substitution and recombination rates from whole-genome sequences and information about poliovirus infection dynamics and the individual vaccination history. We confirmed observations from a recent vaccine trial that VP1 substitution rates are increased for Sabin-like isolates relative to the rate for the wild type due to increased nonsynonymous substitution rates. We also inferred substitution rates for attenuating nucleotides and confirmed that reversion can occur in days to weeks after vaccination. We combine our observations for Sabin-like virus evolution with the molecular clock for VP1 of circulating wild-type strains to infer that the mean time from the initiating vaccine dose to the earliest detection of circulating vaccine-derived poliovirus (cVDPV) is 300 days for Sabin-like virus type 1, 210 days for Sabin-like virus type 2, and 390 days for Sabin-like virus type 3. Phylogenetic relationships indicated transient local transmission of Sabin-like virus type 3 and, possibly, Sabin-like virus type 1 during periods of low wild polio incidence. Comparison of Sabin-like virus recombinants with known Nigerian vaccine-derived poliovirus recombinants shows that while recombination with non-Sabin enteroviruses is associated with cVDPV, the recombination rates are similar for Sabin isolate-Sabin isolate and Sabin isolate-non-Sabin enterovirus recombination after accounting for the time from dosing to the time of detection. Our study provides a comprehensive picture of the evolutionary dynamics of the oral polio vaccine in the field. [ABSTRACT FROM AUTHOR]

Background: Sub-Saharan Africa (SSA) has become a hotspot for global terrorism, with nearly 50% of global terror-related deaths occurring in SSA in 2021. With a large population and complex geopolitical and social climate, terrorist activity further burdens an already strained medical system. This study provides a retrospective descriptive analysis of terrorist-related activity in SSA from 1970-2020., Methods: A retrospective analysis of the Global Terrorism Database (GTD) was performed for the region of SSA from 1970-2020. Data were filtered using the internal database search function for all events in the following countries: Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Comoros, the Democratic Republic of the Congo, Djibouti, Equatorial Guinea, Eritrea, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Kenya, Lesotho, Liberia, Madagascar, Malawi, Mali, Mauritania, Mozambique, Namibia, Niger, Nigeria, People's Republic of the Congo, Republic of the Congo, Rhodesia, Rwanda, Senegal, Seychelles, Sierra Leone, Somalia, South Africa, South Sudan, Sudan, Swaziland, Tanzania, Togo, Uganda, Zaire, Zambia, and Zimbabwe. Number of attacks, deaths, and injuries, as well as primary weapons types, country where attacks occurred, and primary target types, were collated and analyzed., Results: A total 19,320 attacks were recorded, resulting in 77,565 deaths and 52,986 injuries. Firearms were the most frequent weapons used (8,745), followed by explosives (6,031), unknown (2,615), and incendiary (1,246), with all others making up the remainder (683.) Private citizens and property were the most frequently targeted entities (8,031), followed by general government facilities (2,582), police (1,854), business (1,446), military (805), diplomatic government facilities (741), and religious figures/institution (678), with all other targets making up the remainder (3,183)., Conclusion: The majority of deaths from terrorism in SSA are the result of firearm attacks and explosions. Nigeria, Somalia, South Africa, The Democratic Republic of the Congo, and Sudan have had the largest number of attacks since 1970, and Nigeria has the largest number of people killed and injured. The health implications of terrorist attacks are often compounded by violence and pose unique challenges to governments, populations, and aid organizations. By understanding the impact and scope of terrorist activity in SSA, Counter-Terrorism Medicine (CTM) initiatives can be employed to improve health care outcomes.

Background: This multicenter study was undertaken to determine the prevalence of Helicobacter pylori (H. pylori) infection among dyspeptic patients with and without type 2 diabetes mellitus (T2DM)., Methods: Patients with dyspepsia were recruited from tertiary teaching hospitals, three in the South-West and one in the South-South regions of Nigeria, between November 2016 and August 2017. The participants had breath samples analyzed for H. pylori by the Urea Breath Test (UBT) following manufacturer's instructions. Dyspeptic patients who were diagnosed previously with T2DM were recorded. Crosstab using chi-square and correlation analyses were used to test (hypothesis) variables., Results: The entire cohort included 471 dyspeptics, 19 (4%) of whom had T2DM. H. pylori infection was reported in 232/471 (49.3%) dyspeptics and 13/19 T2DM patients, without significant difference between diabetics and nondiabetics. The majority (84.6%) of those positive for UBT and T2DM were in the age group 52-71 years, while none was in the age group 72-91 years. There was no statistical significance (P>0.05) between the age group, UBT and T2DM positive., Conclusions: Our study showed that, in Nigeria, there is no difference in prevalence of H. pylori in dyspeptic patients with and without T2DM.

Unlabelled: To assess the dynamics of genetic reversion of live poliovirus vaccine in humans, we studied molecular evolution in Sabin-like poliovirus isolates from Nigerian acute flaccid paralysis cases obtained from routine surveillance. We employed a novel modeling approach to infer substitution and recombination rates from whole-genome sequences and information about poliovirus infection dynamics and the individual vaccination history. We confirmed observations from a recent vaccine trial that VP1 substitution rates are increased for Sabin-like isolates relative to the rate for the wild type due to increased nonsynonymous substitution rates. We also inferred substitution rates for attenuating nucleotides and confirmed that reversion can occur in days to weeks after vaccination. We combine our observations for Sabin-like virus evolution with the molecular clock for VP1 of circulating wild-type strains to infer that the mean time from the initiating vaccine dose to the earliest detection of circulating vaccine-derived poliovirus (cVDPV) is 300 days for Sabin-like virus type 1, 210 days for Sabin-like virus type 2, and 390 days for Sabin-like virus type 3. Phylogenetic relationships indicated transient local transmission of Sabin-like virus type 3 and, possibly, Sabin-like virus type 1 during periods of low wild polio incidence. Comparison of Sabin-like virus recombinants with known Nigerian vaccine-derived poliovirus recombinants shows that while recombination with non-Sabin enteroviruses is associated with cVDPV, the recombination rates are similar for Sabin isolate-Sabin isolate and Sabin isolate-non-Sabin enterovirus recombination after accounting for the time from dosing to the time of detection. Our study provides a comprehensive picture of the evolutionary dynamics of the oral polio vaccine in the field., Importance: The global polio eradication effort has completed its 26th year. Despite success in eliminating wild poliovirus from most of the world, polio persists in populations where logistical, social, and political factors have not allowed vaccination programs of sustained high quality. One issue of critical importance is eliminating circulating vaccine-derived polioviruses (cVDPVs) that have properties indistinguishable from those of wild poliovirus and can cause paralytic disease. cVDPV emerges due to the genetic instability of the Sabin viruses used in the oral polio vaccine (OPV) in populations that have low levels of immunity to poliovirus. However, the dynamics responsible are incompletely understood because it has historically been difficult to gather and interpret data about evolution of the Sabin viruses used in OPV in regions where cVDPV has occurred. This study is the first to combine whole-genome sequencing of poliovirus isolates collected during routine surveillance with knowledge about the intrahost dynamics of poliovirus to provide quantitative insight into polio vaccine evolution in the field., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Since 2005, a large poliomyelitis outbreak associated with type 2 circulating vaccine-derived poliovirus (cVDPV2) has occurred in northern Nigeria, where immunization coverage with trivalent oral poliovirus vaccine (tOPV) has been low. Phylogenetic analysis of P1/capsid region sequences of isolates from each of the 403 cases reported in 2005 to 2011 resolved the outbreak into 23 independent type 2 vaccine-derived poliovirus (VDPV2) emergences, at least 7 of which established circulating lineage groups. Virus from one emergence (lineage group 2005-8; 361 isolates) was estimated to have circulated for over 6 years. The population of the major cVDPV2 lineage group expanded rapidly in early 2009, fell sharply after two tOPV rounds in mid-2009, and gradually expanded again through 2011. The two major determinants of attenuation of the Sabin 2 oral poliovirus vaccine strain (A481 in the 5'-untranslated region [5'-UTR] and VP1-Ile143) had been replaced in all VDPV2 isolates; most A481 5'-UTR replacements occurred by recombination with other enteroviruses. cVDPV2 isolates representing different lineage groups had biological properties indistinguishable from those of wild polioviruses, including efficient growth in neuron-derived HEK293 cells, the capacity to cause paralytic disease in both humans and PVR-Tg21 transgenic mice, loss of the temperature-sensitive phenotype, and the capacity for sustained person-to-person transmission. We estimate from the poliomyelitis case count and the paralytic case-to-infection ratio for type 2 wild poliovirus infections that ∼700,000 cVDPV2 infections have occurred during the outbreak. The detection of multiple concurrent cVDPV2 outbreaks in northern Nigeria highlights the risks of cVDPV emergence accompanying tOPV use at low rates of coverage in developing countries.

A type 2 vaccine-derived poliovirus (VDPV), differing from Sabin 2 at 2.5% (22/903) of VP1 nucleotide (nt) positions, was isolated from an incompletely immunized 21-month-old Nigerian child who developed acute flaccid paralysis in 2002. Sequences upstream of nt position 620 (within the 5'-untranslated region [5'-UTR]) and downstream of nt position 5840 (in the 3C(pro) region) were derived from species C enteroviruses unrelated to the oral poliovirus vaccine (OPV) strains. The two substitutions associated with the attenuated phenotype had either recombined out (A(481)-->G in the 5'-UTR) or reverted (Ile(143)-->Thr in VP1). The VDPV isolate had lost the temperature sensitive phenotype of Sabin 2 and it was antigenically distinct from the parental OPV strain, having amino acid substitutions in or near neutralizing antigenic sites 1 and 3. The date of the initiating OPV dose, calculated from the number of synonymous substitutions in the capsid region, was estimated to be approximately 16 to 18 months before onset of paralysis, a finding inconsistent with the most recent mass OPV campaign (conducted 12 days before onset of paralysis) as being the source of infection. Although no related type 2 VDPVs were detected in Nigeria or elsewhere, the VDPV was found in an area where conditions favor VDPV emergence and spread.