Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-7 (of 7 Records) |
Query Trace: Zomahoun D[original query] |
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Evaluation of the Acute flaccid paralysis surveillance indicators in Zambia from 2015-2021: a retrospective analysis
Bessing B , Dagoe EA , Tembo D , Mwangombe A , Kanyanga MK , Manneh F , Matapo BB , Bobo PM , Chipoya M , Eboh VA , Kayeye PL , Masumbu PK , Muzongwe C , Bakyaita NN , Zomahoun D , Tuma JN . BMC Public Health 2023 23 (1) 2227 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. |
Update on wild poliovirus type 1 outbreak - Southeastern Africa, 2021-2022
Davlantes E , Greene SA , Tobolowsky FA , Biya O , Wiesen E , Abebe F , Weldetsadik MB , Eboh VA , Chisema MN , da Conceição Mário B , Tinuga F , Bobo PM , Chigodo CK , Sethy G , Hellström JM , Goundara AM , Burny ME , Mwale JC , Jorba J , Makua KS , Howard W , Seakamela L , Okiror S , Thompson A , Ali A , Samba D , Agbo C , Kabamba L , Kazoka A , Zomahoun DL , Manneh F , Abdelrahim K , Kamugisha C , Umar AS . MMWR Morb Mortal Wkly Rep 2023 72 (15) 391-397 Since the Global Polio Eradication Initiative (GPEI) began in 1988, the number of wild poliovirus (WPV) cases has declined by >99.99%. Five of the six World Health Organization (WHO) regions have been certified free of indigenous WPV, and WPV serotypes 2 and 3 have been declared eradicated globally (1). WPV type 1 (WPV1) remains endemic only in Afghanistan and Pakistan (2,3). Before the outbreak described in this report, WPV1 had not been detected in southeastern Africa since the 1990s, and on August 25, 2020, the WHO African Region was certified free of indigenous WPV (4). On February 16, 2022, WPV1 infection was confirmed in one child living in Malawi, with onset of paralysis on November 19, 2021. Genomic sequence analysis of the isolated poliovirus indicated that it originated in Pakistan (5). Cases were subsequently identified in Mozambique. This report summarizes progress in the outbreak response since the initial report (5). During November 2021-December 2022, nine children and adolescents with paralytic polio caused by WPV1 were identified in southeastern Africa: one in Malawi and eight in Mozambique. Malawi, Mozambique, and three neighboring countries at high risk for WPV1 importation (Tanzania, Zambia, and Zimbabwe) responded by increasing surveillance and organizing up to six rounds of national and subnational polio supplementary immunization activities (SIAs).* Although no cases of paralytic WPV1 infection have been reported in Malawi since November 2021 or in Mozambique since August 2022, undetected transmission might be ongoing because of poliovirus surveillance gaps and testing delays. Efforts to further enhance poliovirus surveillance sensitivity, improve SIA quality, and strengthen routine immunization are needed to ensure that WPV1 transmission has been interrupted within 12 months of the first case, thereby preserving the WHO African Region's WPV-free status. |
The immediate impact of the COVID-19 pandemic on polio immunization and surveillance activities.
Burkholder B , Wadood Z , Kassem AM , Ehrhardt D , Zomahoun D . Vaccine 2021 41 Suppl 1 A2-A11 In addition to affecting individual health the COVID-19 pandemic has disrupted efforts to deliver essential health services around the world. In this article we present an overview of the immediate programmatic and epidemiologic impact of the pandemic on polio eradication as well as the adaptive strategic and operational measures taken by the Global Polio Eradication Initiative (GPEI) from March through September 2020. Shortly after the World Health Organization (WHO) declared a global pandemic on 11 March 2020, the GPEI initially redirected the programme's assets to tackle COVID-19 and suspended house-to-house supplementary immunization activities (SIAs) while also striving to continue essential poliovirus surveillance functions. From March to May 2020, 28 countries suspended a total of 62 polio vaccine SIAs. In spite of efforts to continue poliovirus surveillance, global acute flaccid paralysis (AFP) cases reported from January-July 2020 declined by 34% compared with the same period in 2019 along with decreases in the mean number of environment samples collected per active site in the critical areas of the African and Eastern Mediterranean regions. The GPEI recommended countries should resume planning and implementation of SIAs starting in July 2020 and released guidelines to ensure these could be done safely for front line workers and communities. By the end of September 2020, a total of 14 countries had implemented circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreak response vaccination campaigns and Afghanistan and Pakistan restarted SIAs to stop ongoing wild poliovirus type 1 (WPV1) transmission. The longer-term impacts of disruptions to eradication efforts remain to be determined, especially in terms of the effect on poliovirus epidemiology. Adapting to the pandemic situation has imposed new considerations on program implementation and demonstrated not only GPEI's contribution to global health security, but also identified potential opportunities for coordinated approaches across immunization and health services. |
Stopping a polio outbreak in the midst of war: Lessons from Syria
Mbaeyi C , Moran T , Wadood Z , Ather F , Sykes E , Nikulin J , Al Safadi M , Stehling-Ariza T , Zomahoun L , Ismaili A , Abourshaid N , Asghar H , Korukluoglu G , Duizer E , Ehrhardt D , Burns CC , Sharaf M . Vaccine 2021 39 (28) 3717-3723 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. |
Impact of COVID-19 Pandemic on Global Poliovirus Surveillance.
Zomahoun DJ , Burman AL , Snider CJ , Chauvin C , Gardner T , Lickness JS , Ahmed JA , Diop O , Gerber S , Anand A . MMWR Morb Mortal Wkly Rep 2021 69 (5152) 1648-1652 On January 30, 2020, the World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) a Public Health Emergency of International Concern (1). On March 24, 2020, the Global Polio Eradication Initiative (GPEI) suspended all polio supplementary immunization activities and recommended the continuation of polio surveillance (2). In April 2020, GPEI shared revised polio surveillance guidelines in the context of the COVID-19 pandemic, which focused on reducing the risk for transmission of SARS-CoV-2, the virus that causes COVID-19, to health care workers and communities by modifying activities that required person-to-person contact, improving hand hygiene and personal protective equipment use practices, and overcoming challenges related to movement restrictions, while continuing essential polio surveillance functions (3). GPEI assessed the impact of the COVID-19 pandemic on polio surveillance by comparing data from January to September 2019 to the same period in 2020. Globally, the number of acute flaccid paralysis (AFP) cases reported declined 33% and the mean number of days between the second stool collected and receipt by the laboratory increased by 70%. Continued analysis of AFP case reporting and stool collection is critical to ensure timely detection and response to interruptions of polio surveillance. |
Strategic Response to an Outbreak of Circulating Vaccine-Derived Poliovirus Type 2 - Syria, 2017-2018.
Mbaeyi C , Wadood ZM , Moran T , Ather F , Stehling-Ariza T , Nikulin J , Al Safadi M , Iber J , Zomahoun L , Abourshaid N , Pang H , Collins N , Asghar H , Butt OUI , Burns CC , Ehrhardt D , Sharaf M . MMWR Morb Mortal Wkly Rep 2018 67 (24) 690-694 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. |
Field investigation with real-time virus genetic characterisation support of a cluster of Ebola virus disease cases in Dubréka, Guinea, April to June 2015.
Pini A , Zomahoun D , Duraffour S , Derrough T , Charles M , Quick J , Loman N , Cowley L , Leno M , Ouedraogo N , Thiam O , Hernandez-Romieu A , Iko A , Keita H , Konate D , Soumah AA , Bouchouar E , Ileka-Priouzeau S , Keita S , Diallo B , Cisse F , Jansa J , Carroll M , Gunther S , Severi E , Formenty P . Euro Surveill 2018 23 (12) On 11 May 2015, the Dubreka prefecture, Guinea, reported nine laboratory-confirmed cases of Ebola virus disease (EVD). None could be epidemiologically linked to cases previously reported in the prefecture. We describe the epidemiological and molecular investigations of this event. We used the Dubreka EVD registers and the Ebola treatment centre's (ETC) records to characterise chains of transmission. Real-time field Ebola virus sequencing was employed to support epidemiological results. An epidemiological cluster of 32 cases was found, of which 27 were laboratory confirmed, 24 were isolated and 20 died. Real-time viral sequencing on 12 cases demonstrated SL3 lineage viruses with sequences differing by one to three nt inside a single phylogenetic cluster. For isolated cases, the average time between symptom onset and ETC referral was 2.8 days (interquartile range (IQR): 1-4). The average time between sample collection and molecular results' availability was 3 days (IQR: 2-5). In an area with scarce resources, the genetic characterisation supported the outbreak investigations in real time, linking cases where epidemiological investigation was limited and reassuring that the responsible strain was already circulating in Guinea. We recommend coupling thorough epidemiological and genomic investigations to control EVD clusters. |
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