National Committee for the Certification of Wild Poliovirus Eradication in Hong Kong. Fifteen years of acute flaccid paralysis surveillance in Hong Kong: findings from 1997 to 2011

Cases of Acute Flaccid Paralysis Associated with Coxsackievirus A2: Findings of a 20-Year Surveillance in the Russian Federation

Surveillance for acute flaccid paralysis syndrome (AFP) in children under 15 is the backbone of the Global Polio Eradication Initiative. Laboratory examination of stool samples from AFP cases allows the detection of, along with polioviruses, a variety of non-polio enteroviruses (NPEV). The etiological significance of these viruses in the occurrence of AFP cases has been definitively established only for enteroviruses A71 and D68. Enterovirus Coxsackie A2 (CVA2) is most often associated with vesicular pharyngitis and hand, foot and mouth disease. Among 7280 AFP cases registered in Russia over 20 years (2001–2020), CVA2 was isolated only from five cases. However, these included three children aged 3 to 4 years, without overt immune deficiency, immunized with 4–5 doses of poliovirus vaccine in accordance with the National Vaccination Schedule. The disease resulted in persistent residual paralysis. Clinical and laboratory data corresponded to poliomyelitis developing during poliovirus infection. These findings are compatible with CVA2 being the cause of AFP. Molecular analysis of CVA2 from these patients and a number of AFP cases in other countries did not reveal association with a specific phylogenetic group, suggesting that virus genetics is unlikely to explain the pathogenic profile. The overall results highlight the value of AFP surveillance not just for polio control but for studies of uncommon AFP agents.

Isolation and molecular characterization of Adenovirus in suspected acute flaccid paralysis patients: A preliminary report from Pakistan

Human adenoviruses (HAdVs) usually cause asymptomatic or mild infection, but infrequently, they are responsible for various severe syndromes including neurological disorders. Various research studies have investigated the association of HAdVs with acute flaccid paralysis (AFP). The purpose of this study was to investigate the genetic diversity of HAdVs and their association with AFP. Stool samples from patients ≤ 12 years of age with suspected AFP were collected from all over Pakistan within the framework of poliovirus surveillance. Poliovirus- and enterovirus-negative samples were screened for HAdVs. For virus isolation, the human epithelial cell line HEp-2c was used, culture-positive samples were screened by nested PCR assay, and partial hexon gene sequences were used for genotype identification. Out of 172 samples, 94 were positive by virus isolation, 89 were positive by PCR, and 32 isolates were genotyped successfully. Phylogenetic analysis showed that the HAdVs belonged to species A (HAdV-A12 and A31), B (HAdV-B3 and B7), C (HAdV-C1 and C6), D (HAdV-D19 and D93), and F (HAdV-F41), showing 99-100% nucleotide sequence identity and 98.3-100% amino acid sequence identity). Most of these genotypes have been reported previously in AFP cases, but this is the first report of the detection of HAdV-D93 in stool samples from AFP cases. The detection of a significant fraction of the HAdVs genotypes indicates that these genetically distinct genotypes are circulating in Pakistan and suggests their possible role in the pathogenesis of AFP.

Type B coxsackieviruses and central nervous system disorders: critical review of reported associations

Type B coxsackieviruses (CV-B) frequently infect the central nervous system (CNS) causing neurological diseases notably meningitis and encephalitis. These infections occur principally among newborns and children. Epidemiological studies of patients with nervous system disorders demonstrate the presence of infectious virus, its components, or anti-CV-B antibodies. Some experimental studies conducted in vitro and in vivo support the potential association between CV-B and idiopathic neurodegenerative diseases such as amyotrophic lateral sclerosis and psychiatric illness such as schizophrenia. However, mechanisms explaining how CV-B infections may contribute to the genesis of CNS disorders remain unclear. The proposed mechanisms focus on the immune response following the viral infection as a contributor to pathogenesis. This review describes these epidemiological and experimental studies, the modes of transmission of CV-B with an emphasis on congenital transmission, the routes used by CV-B to reach the brain parenchyma, and plausible mechanisms by which CV-B may induce CNS diseases, with a focus on potential immunopathogenesis.

Evaluation of the Acute Flaccid Paralysis Surveillance System in Polio-Free Jordan, 2012-2016: Retrospective Secondary Analysis

Background

As part of the polio-eradication strategy, the World Health Organization (WHO) has established a global acute flaccid paralysis (AFP) surveillance system. AFP surveillance has successfully helped Jordan achieve polio-free certification. However, there is a substantial risk of polio importation from neighboring countries including Syria and Iraq.

Objective

This study aimed to evaluate the AFP surveillance in Jordan and identify areas that need improvement.

Methods

This retrospective study is a secondary analysis of data that were routinely collected between 2012 and 2016 by Jordan’s Expanded Program on Immunization. The WHO’s minimum performance indicators were used to evaluate the AFP surveillance.

Results

Cumulatively, 328 AFP cases had been reported. Almost half (n=168, 51.3%) of the patients were aged 1-5 years, and 55.8% (n=183) were male. All cases were discarded (classified as a nonpolio case). The most common cause of AFP was Guillain-Barre Syndrome (n=115, 35.1%). The annualized nonpolio AFP rate increased from 1.4/100,000 children below 15 years of age in 2012 to 4.3 in 2016. National and subnational sensitivities were not met in 2012 and 2013. Adequacy of stool specimens and timeliness of specimens arriving at and processed in the laboratory were constantly above the minimum target. Timeliness of the investigation met the expected target but with a decreasing trend. The nonpolio enterovirus isolation rate was below the target, except in 2016.

Conclusions

The AFP surveillance system in Jordan is performing well; however, additional efforts are needed to strengthen the subnational sensitivity. The cold chain from sample collection to laboratory testing has to be maintained to ensure the reliability of stool specimens required for isolation of the nonpolio enterovirus.

Prevalence and outcomes of Guillain-Barré syndrome among pediatrics in Saudi Arabia: a 10-year retrospective study

BACKGROUND

Guillain-Barré syndrome (GBS) is a progressive acute form of paralysis most probably secondary to an immune-mediated process. GBS among Saudis has been seldom investigated, which leaves both clinicians and researchers with scarcity in knowledge. Therefore, this study aims to assess the prevalence and clinical prognosis of GBS among pediatrics admitted with acute paralysis at a large healthcare facility in Riyadh, Saudi Arabia.

METHODS

This retrospective study reviewed patients' medical records between 2005 and 2015. Eligible cases were children (<14 years old) admitted to the hospital complaining of acute paralysis and later diagnosed with one form or variant of GBS. Pearson's chi-square, Fisher's exact test, and binary logistic regression were employed to analyze the collected data.

RESULTS

The prevalence of GBS was 49%. The male-to-female ratio was 1.45:1. The mean ± standard deviation age was 7±3.7 years. There were 34 (69.4%) cases with progression to maximum paralysis in ≤2 weeks, while 15 (30.6%) cases occurred beyond 2 weeks. Males (n=24, 82.8%) were more likely to endure progression to maximum paralysis in ≤2 weeks after the disease onset, compared to females (n=10, 50%), P=0.014. All cases complaining of respiratory problems exhibited a progression to maximum paralysis in ≤2 weeks, compared to those with no respiratory problems, P=0.027. Residual paralysis at 60 days post disease onset was highly associated with GBS patients of age 8-14 years (n=15, 65.2%), compared to younger patients (n=8, 30.8%), P=0.016. Patients admitted in colder seasons (n=14, 63.6%) were more likely to suffer residual paralysis too, compared to those in warmer seasons (n=9, 33.3%), P=0.035. GBS cases who complained of facial weakness (n=9, 75%) and ocular abnormalities (n=10, 71.4%) were also more likely to endure residual paralysis at 60 days post disease onset, P=0.025 and P=0.03, respectively.

CONCLUSION

Male gender could be a determinant of rapid progression to maximum paralysis, while the older age group in pediatrics is expected to endure residual paralysis at 60 days post disease onset. GBS can be accounted as a rare disease, especially in pediatrics, so confirmed cases should be investigated comprehensively for research purposes.

Characterization of group B coxsackieviruses isolated from non-polio acute flaccid paralysis patients in Pakistan: vital assessment before polio eradication

Pakistan is at the verge of polio eradication but isolation of non-polio enteroviruses (NPEVs) from acute flaccid paralysis (AFP) cases may result in serious or even fatal outcome. Many enteroviruses share similar symptoms and epidemiology as is the case with poliovirus and coxsackievirus (CV). The present study was designed to genetically characterize coxsackievirus B (CV-B) serotypes isolated from non-polio acute flaccid paralytic children, as well as to understand their probable role in paralysis. A total of 63 (20·1%) out of 313 stool samples during 2013 were found positive for NPEVs in rhabdomyosarcoma cells. Only 24 (38·0%) NPEVs were typed as CV-B by microneutralization assay and were further characterized by sequencing of the viral protein 1 (VP1) gene. Molecular phylogenetic analyses classified the study strains into six coxsackievirus B serotypes (coxsackievirus B1 to B6) with their respective prototype strains with evidence of epidemiological linkage and distinct clusters. Moreover, four major differences were found within the amino acid sequences of BC-loop in VP1 of CV-B strains. In conclusion, this study presented the molecular evolutionary genetic overview and distinct phylogenetic pattern of CV-B isolates from AFP cases in Pakistan, and explored the possible link between CV-B infections and AFP cases. Furthermore, our data reveal that these viruses might contribute to the incidence of paralysis in population and there is need of time to establish an enterovirus surveillance system for better understanding of epidemiological and virological characteristics of NPEV infections associated with AFP cases in the country.

Management of the 2014 Enterovirus 68 Outbreak at a Pediatric Tertiary Care Center

PURPOSE

Enterovirus 68 (EV-D68) is an uncommonly recognized cause of acute respiratory tract infections. During the late summer of 2014, an international EV-D68 outbreak occurred. We review the steps of outbreak recognition and management in the context of 1 hospital's experience with the EV-D68 outbreak.

METHODS

We reviewed the role of Children's Mercy Hospital as one of the first hospitals to recognize the 2014 EV-D68 outbreak in the United States. The steps of outbreak management were applied to real-life examples as the outbreak unfolded at our hospital.

FINDINGS

Management of the 2014 EV-D68 outbreak was a multifaceted effort requiring close coordination with hospitals, local and state health departments, and the Centers for Disease Control and Prevention. The importance of clear and frequent communication is highlighted both intra- and interinstitutionally. Increased respiratory disease-related pediatric admissions at hospitals nationally were attributed to EV-D68. Outcomes for these children, including the association of EV-D68 with acute flaccid myelitis, remain under investigation.

IMPLICATIONS

Following the steps of outbreak management is critical to providing optimal patient care and ensuring the health of the public. During the 2014 EV-D68 outbreak, close adherence to outbreak principles led to swift recognition of illness, rapid diagnostic measures, institution of appropriate therapies, and dissemination of information to health care providers and the public. Equally important was the subsequent identification of an increase in acute flaccid myelitis cases against the backdrop of an increase in EV-D68 detections nationally. Future prospective studies are needed to determine the true burden of EV-D68 disease, potential vaccines and therapeutics, and outcomes of children with EV-D68 infection.