Persistent Transmission of Circulating Vaccine-Derived Poliovirus - Somalia, January 2017-March 2024.

Since the launch of the Global Polio Eradication Initiative in 1988, substantial progress has been made in the interruption of wild poliovirus (WPV) transmission worldwide: global eradication of WPV types 2 and 3 were certified in 2015 and 2019, respectively, and endemic transmission of WPV type 1 continues only in Afghanistan and Pakistan. After the synchronized global withdrawal of all serotype 2 oral poliovirus vaccines (OPVs) in 2016, widespread outbreaks of circulating vaccine-derived poliovirus type 2 (cVDPV2) have occurred, which are linked to areas with low population immunity to poliovirus. Officials in Somalia have detected ongoing cVDPV2 transmission since 2017. Polio vaccination coverage and surveillance data for Somalia were reviewed to assess this persistent transmission. During January 2017-March 2024, officials in Somalia detected 39 cVDPV2 cases in 14 of 20 regions, and transmission has spread to neighboring Ethiopia and Kenya. Since January 2021, 28 supplementary immunization activities (SIAs) targeting cVDPV2 were conducted in Somalia. Some parts of the country are security-compromised and inaccessible for vaccination campaigns. Among 1,921 children with nonpolio acute flaccid paralysis, 231 (12%) had not received OPV doses through routine immunization or SIAs, 95% of whom were from the South-Central region, and 60% of whom lived in inaccessible districts. Enhancing humanitarian negotiation measures in Somalia to enable vaccination of children in security-compromised areas and strengthening campaign quality in accessible areas will help interrupt cVDPV2 transmission.

Strategic Response to an Outbreak of Circulating Vaccine-Derived Poliovirus Type 2 - Syria, 2017-2018.

Since the 1988 inception of the Global Polio Eradication Initiative (GPEI), progress toward interruption of wild poliovirus (WPV) transmission has occurred mostly through extensive use of oral poliovirus vaccine (OPV) in mass vaccination campaigns and through routine immunization services (1,2). However, because OPV contains live, attenuated virus, it carries the rare risk for reversion to neurovirulence. In areas with very low OPV coverage, prolonged transmission of vaccine-associated viruses can lead to the emergence of vaccine-derived polioviruses (VDPVs), which can cause outbreaks of paralytic poliomyelitis. Although WPV type 2 has not been detected since 1999, and was declared eradicated in 2015,* most VDPV outbreaks have been attributable to VDPV serotype 2 (VDPV2) (3,4). After the synchronized global switch from trivalent OPV (tOPV) (containing vaccine virus types 1, 2, and 3) to bivalent OPV (bOPV) (types 1 and 3) in April 2016 (5), GPEI regards any VDPV2 emergence as a public health emergency (6,7). During May-June 2017, VDPV2 was isolated from stool specimens from two children with acute flaccid paralysis (AFP) in Deir-ez-Zor governorate, Syria. The first isolate differed from Sabin vaccine virus by 22 nucleotides in the VP1 coding region (903 nucleotides). Genetic sequence analysis linked the two cases, confirming an outbreak of circulating VDPV2 (cVDPV2). Poliovirus surveillance activities were intensified, and three rounds of vaccination campaigns, aimed at children aged <5 years, were conducted using monovalent OPV type 2 (mOPV2). During the outbreak, 74 cVDPV2 cases were identified; the most recent occurred in September 2017. Evidence indicates that enhanced surveillance measures coupled with vaccination activities using mOPV2 have interrupted cVDPV2 transmission in Syria.

Assessing country compliance with circulating vaccine-derived poliovirus type 2 outbreak response standard operating procedures: April 2016 to December 2020.

BACKGROUND: Trivalent oral poliovirus vaccine (tOPV) was globally replaced with bivalent oral poliovirus vaccine (bOPV) in April 2016 ("the switch"). Many outbreaks of paralytic poliomyelitis associated with type 2 circulating vaccine-derived poliovirus (cVDPV2) have been reported since this time. The Global Polio Eradication Initiative (GPEI) developed standard operating procedures (SOPs) to guide countries experiencing cVDPV2 outbreaks to implement timely and effective outbreak response (OBR). To assess the possible role of compliance with SOPs in successfully stopping cVDPV2 outbreaks, we analyzed data on critical timelines in the OBR process. METHODS: Data were collected on all cVDPV2 outbreaks detected for the period April 1, 2016 and December 31, 2020 and all outbreak responses to those outbreaks between April 1, 2016 and December 31, 2021. We conducted secondary data analysis using the GPEI Polio Information System database, records from the U.S. Centers for Disease Control and Prevention Polio Laboratory, and meeting minutes of the monovalent OPV2 (mOPV2) Advisory Group. Date of notification of circulating virus was defined as Day 0 for this analysis. Extracted process variables were compared with indicators in the GPEI SOP version 3.1. RESULTS: One hundred and eleven cVDPV2 outbreaks resulting from 67 distinct cVDPV2 emergences were reported during April 1, 2016-December 31, 2020, affecting 34 countries across four World Health Organization Regions. Out of 65 OBRs with the first large-scale campaign (R1) conducted after Day 0, only 12 (18.5%) R1s were conducted by the target of 28 days after Day 0. Of the 89 OBRs with the second large-scale campaign (R2) conducted after Day 0, 30 (33.7%) R2s were conducted by the target of 56 days after Day 0. Twenty-three (31.9%) of the 72 outbreaks with isolates dated after Day 0 were stopped within the 120-day target. CONCLUSION: Since "the switch", delays in OBR implementation were evident in many countries, which may be related to the persistence of cVDPV2 outbreaks >120 days. To achieve timely and effective response, countries should follow GPEI OBR guidelines.

Stopping a polio outbreak in the midst of war: Lessons from Syria.

BACKGROUND: Outbreaks of circulating vaccine-derived polioviruses (cVDPVs) pose a threat to the eventual eradication of all polioviruses. In 2017, an outbreak of cVDPV type 2 (cVDPV2) occurred in the midst of a war in Syria. We describe vaccination-based risk factors for and the successful response to the outbreak. METHODS: We performed a descriptive analysis of cVDPV2 cases and key indicators of poliovirus surveillance and vaccination activities during 2016-2018. In the absence of reliable subnational coverage data, we used the caregiver-reported vaccination status of children with non-polio acute flaccid paralysis (AFP) as a proxy for vaccination coverage. We then estimated the relative odds of being unvaccinated against polio, comparing children in areas affected by the outbreak to children in other parts of Syria in order to establish the presence of poliovirus immunity gaps in outbreak affected areas. FINDINGS: A total of 74 cVDPV2 cases were reported, with paralysis onset ranging from 3 March to 21 September 2017. All but three cases were reported from Deir-ez-Zor governorate and 84% had received < 3 doses of oral poliovirus vaccine (OPV). After adjusting for age and sex, non-polio AFP case-patients aged 6-59 months in outbreak-affected areas had 2.5 (95% CI: 1.1-5.7) increased odds of being unvaccinated with OPV compared with non-polio AFP case-patients in the same age group in other parts of Syria. Three outbreak response rounds of monovalent OPV type 2 (mOPV2) vaccination were conducted, with governorate-level coverage mostly exceeding 80%. INTERPRETATION: Significant declines in both national and subnational polio vaccination coverage, precipitated by war and a humanitarian crisis, led to a cVDPV2 outbreak in Syria that was successfully contained following three rounds of mOPV2 vaccination.

Diagnoses, infections and injuries in Northern Syrian children during the civil war: A cross-sectional study.

BACKGROUND: The civil war in Syria including the deliberate targeting of healthcare services resulted in a complex humanitarian emergency, seriously affecting children's health. The objectives of this study are to document diagnoses and disease categories in Northern Syrian children after four years of conflict, and to document infectious diseases and injuries in this vulnerable population. METHODS: In a prospective cross-sectional observational sample study conducted in May 2015, healthcare workers registered demographics, comorbidities, and diagnoses (categorised according to the International Classification of Diseases version 10) in children visited at home and in internally displaced persons camps in four Syrian governorates. RESULTS: Of 1080 filled-out records, 1002 were included. Children originated from Aleppo (41%), Idleb (36%), Hamah (15%) and Lattakia (8%). Median age was 6 years (0-15; IQR 3-11), 61% were boys, 40% were younger than 5 years old. Children suffered from respiratory (29%), neurological (19%), digestive (17%), eye (5%) and skin (5%) diseases. Clinical malnutrition was seen in 4%, accidental injury in 3%, intentional injury in 1%, and mental disorders in 2%. Overall, 64% had features of infectious diseases (OR 0.635; CI 0.605-0.665). Most common comorbidities were chronic respiratory diseases (14, malnutrition (5%), acute flaccid paralysis (5%), and epilepsy (4%). Logistic regression analysis indicated that the risk for children to have communicable diseases was higher in Aleppo than in Idleb (OR 1.7; CI 1.2-2.3), Hamah (OR 4.9; CI 3.3-7.5), or Lattakia (OR 5.5; CI 3.3-9.3). Children in Aleppo and Lattakia were more at risk to be injured than in Idleb (OR 5.6; CI 2.1-14.3), or in Hamah (OR 5.9; CI 1.4-25.6), but more often from intentional violence in Lattakia. Mental problems were more prominent in Hamah. CONCLUSIONS: Four years far in the conflict, 64% of the studied children in four Northern Syrian governorates suffer from infections, mostly from respiratory, neurological and digestive origin, while 4% was injured or victim of intentional aggression. Substandard living conditions and the lack of paediatric healthcare put Syrian children at risk for serious infections, epidemics and morbidity, and ask for urgent international humanitarian relief efforts.

Children in the Syrian Civil War: the Familial, Educational, and Public Health Impact of Ongoing Violence.

OBJECTIVE: The Syrian civil war since 2011 has led to one of the most complex humanitarian emergencies in history. The objective of this study was to document the impact of the conflict on the familial, educational, and public health state of Syrian children. METHODS: A cross-sectional observational study was conducted in May 2015. Health care workers visited families with a prospectively designed data sheet in 4 Northern Syrian governorates. RESULTS: The 1001 children included in this study originated from Aleppo (41%), Idleb (36%), Hamah (15%), and Lattakia (8%). The children's median age was 6 years (range, 0-15 years; interquartile range, 3-11 years), and 61% were boys. Almost 20% of the children were internally displaced, and 5% had deceased or missing parents. Children lacked access to safe drinking water (15%), appropriate sanitation (23%), healthy nutrition (16%), and pediatric health care providers (64%). Vaccination was inadequate in 72%. More than half of school-aged children had no access to education. Children in Idleb and Lattakia were at greater risk of having unmet public health needs. Younger children were at greater risk of having an incomplete vaccination state. CONCLUSIONS: After 4 years of civil war in Syria, children have lost parents, live in substandard life quality circumstances, and are at risk for outbreaks because of worsening vaccination states and insufficient availability of health care providers. (Disaster Med Public Health Preparedness. 2016;10:874-882).

Abdominal Pain-Predominant Functional Gastrointestinal Disorders in Jordanian School Children.

BACKGROUND: Recurrent abdominal pain (RAP) is a common complaint in children. Significant portion of them are of functional origin. This study aimed to assess the prevalence of abdominal pain-predominant functional gastrointestinal disorder (FGID) and its types in Jordanian school children. METHODS: This is a school-based survey at south Jordan. Information using the self-reporting form of the Questionnaire on Pediatric Gastrointestinal Symptoms-Rome III Version (QPGS-RIII) - the official Arabic translation - was collected. Classes from academic years (grades) 6 - 8 were selected. SPSS Statistical Package Version 17 (IBM, Armonk, NY, USA) was used. Categorical data were analyzed using Fisher's exact test, and continuous data were analyzed using t-test. P < 0.05 was considered significant. RESULTS: Five hundred questionnaires were distributed, and 454 returned answered (91%). Two hundred twenty-nine (50.8%) were males. The average age of participants was 12.7 years (11 - 15 years). One hundred sixteen (25.7%) had abdominal pain-predominant FGID. Seventy-nine (68%) of them were females. Forty-seven (10.6%) had irritable bowel syndrome (IBS). Thirty-six (8%), 17 (3.8%), 11 (2.4%) and five (1.1%) had abdominal migraine, functional abdominal pain, functional abdominal pain syndrome and functional dyspepsia, respectively. CONCLUSION: Abdominal pain-predominant FGID has become a major health issue in Jordanian children. One of four children between the ages of 11 and 15 years exhibits at least one abdominal pain-predominant FGID. The most common form of abdominal pain-predominant FGID in our children was IBS. Females are affected more often than males. Intestinal and extra-intestinal symptoms are seen regularly with abdominal pain-predominant FGIDs.