Search

In 2022, an estimated 5 million persons in the WHO Region of the Americas (AMR) were living with chronic hepatitis B virus (HBV) infection, the leading cause of hepatocellular carcinoma and cirrhosis worldwide. Most chronic infections are acquired through mother-to-child transmission (MTCT) or horizontal transmission during childhood and are preventable with HBV vaccination, including a birth dose (HepB-BD), followed by 2-3 additional doses (HepB3) in infancy. The aim of the Pan American Health Organization (PAHO) Elimination of MTCT of HBV strategy (EMTCT Plus) is intented to reduce the prevalence of chronic HBV infection (measured as hepatitis B surface antigen [HBsAg]) among children to [less than or equal to]0.1% by achieving 1) [greater than or equal to]95% coverage with HepB-BD and HepB3 and 2) increasing HBsAg testing among pregnant women and provision of hepatitis B immunoglobulin to HBV-exposed neonates to [greater than or equal to]80%. By 2012, all 51 countries and territories (countries) in the AMR had provided HepB3 nationwide; and, by 2021, 34 (67%) had provided HepB-BD nationwide. Mathematical models were used to estimate that the HBsAg prevalence in children is [less than or equal to] 0.1% in 14 (28%) countries and at regional level. Three (6%) of 51 countries met the 95% coverage targets for both HepB3 and HepB-BD during both 2021 and 2022. Of these, 2 have probably met the criteria for EMTCT of HBV infection. In 2022, however, HepB3 coverage was [greater than or equal to] 10 percentage points lower in 15 (37%) of 41 countries with 2012 coverage data for comparison. These decreases in HepB3 coverage and the absence of HepB-BD from the routine immunization schedules in 17 countries threaten the Region&apos;s progress towards the EMTCT of HBV infection. Efforts to introduce HepB-BD and to maintain high HepB3 and HepB-BD coverage are necessary. En 2022, on estimait a 5 millions le nombre de personnes vivant avec une infection chronique par le virus de l&apos;hepatite B (VHB) dans la Region OMS des Ameriques, principale cause de carcinome hepatocellulaire et de cirrhose dans le monde. La plupart des infections chroniques sont contractees par transmission mere-enfant (TME) ou par transmission horizontale pendant l&apos;enfance et peuvent etre evitees grace a la vaccination contre le VHB, notamment par l&apos;administration d&apos;une dose a la naissance (DN-HepB), suivie de 2 a 3 doses supplementaires (HepB3) dans la petite enfance. La strategie d&apos;elimination de la transmission mere-enfant du VHB (EMTCT Plus) de l&apos;Organisation panamericaine de la Sante (OPS) vise a reduire la prevalence de l&apos;infection chronique par le VHB (mesuree par une prevalence de l&apos;antigene de surface du virus de l&apos;hepatite B [AgHBs]) [less than or equal to]0,1% chez les enfants) en parvenant a: 1) une couverture [greater than or equal to]95% par la DN-HepB et la HepB3 et 2) une couverture [greater than or equal to]80% du depistage a la recherche de l&apos;AgHBs chez les femmes enceintes et de l&apos;administration d&apos;immunoglobulines antihepatite B aux nouveau-nes exposes au VHB. En 2012, les 51 pays et territoires (ci-apres <>) de la Region des Ameriques administraient la HepB3 a l&apos;echelle nationale; en 2021, 34 pays (67%) administraient la DN-HepB a l&apos;echelle nationale. Des modeles mathematiques ont permis d&apos;estimer que la prevalence de l&apos;AgHBs chez les enfants etait [less than or equal to] 0,1% dans 14 pays (28%) et au niveau regional. Trois des 51 pays (6%) avaient atteint la cible d&apos;une couverture de 95% par la HepB3 et la DN-HepB en 2021 et en 2022, dont 2 remplissaient probablement les criteres de l&apos;elimination de la TME de l&apos;infection par le VHB. En 2022, cependant, la couverture par la HepB3 etait inferieure de [greater than or equal to] 10 points de pourcentage dans 15 des 41 pays (37%) pour lesquels les donnees de couverture de 2012 etaient disponibles a des fins de comparaison. Cette diminution de la couverture par la HepB3 et l&apos;absence de la DN-HepB dans les calendriers de vaccination systematique dans 17 pays menacent les progres de la Region vers l&apos;elimination de la TME de l&apos;infection par le VHB. Il est necessaire de deployer des efforts pour introduire la DN-HepB et maintenir une couverture elevee par la HepB3 et la DN-HepB., Introduction Globally, chronic HBV infection is the leading cause of hepatocellular carcinoma and cirrhosis. (1) In 2022, an estimated 5 million people in the AMR (2) had chronic HBV infection, [...]

As of 1 May 2016, the use of oral poliovirus vaccine (OPV) type 2 for routine and supplementary immunization activities (SIAs) ceased after a synchronized global switch from trivalent OPV [...]

Circulating vaccine-derived polioviruses (cVDPVs) can emerge in areas with low poliovirus immunity and cause outbreaks (1) of paralytic polio. (2-6) Of the 3 types of wild poliovirus, type 2 was [...]

Widespread use of live, attenuated (Sabin) oral poliovirus vaccine (OPV) has resulted in marked progress towards global poliomyelitis eradication. (1) In under-immunized populations, however, extensive person-to-person transmission of Sabin poliovirus [...]

The last confirmed wild poliovirus (WPV) case in Democratic Republic of the Congo (DRC) had paralysis onset in December 2011. (1) DRC has documented cases of vaccine-derived polioviruses (VDPVs) since [...]

Through the Mectizan® Donation Program, Merck & Co., Inc. has donated Mectizan (ivermectin, MSD) for the treatment of onchocerciasis worldwide since 1987. Mectizan has also been donated for the elimination of lymphatic filariasis (LF) since 1998 in African countries and in Yemen where onchocerciasis and LF are co-endemic; for LF elimination programs, Mectizan is co-administered with albendazole, which is donated by GlaxoSmithKline. The Mectizan Donation Program works in collaboration with the Mectizan Expert Committee/Albendazole Coordination, its scientific advisory committee. In 2005, a total of 62,201,310 treatments of Mectizan for onchocerciasis were approved for delivery via mass treatment programs in Africa, Latin America, and Yemen. Seventy-seven percent and 20% of these treatments for onchocerciasis were for countries included in the African Programme for Onchocerciasis Control (APOC) and the former-Onchocerciasis Control Programme in West Africa (OCP), respectively. The remaining 3% of treatments approved were for the six onchocerciasis endemic countries in Latin America, where mass treatment is carried out twice-yearly with the goal of completely eliminating morbidity and eventually transmission of infection, and for Yemen. All 33 onchocerciasis endemic countries where mass treatment with Mectizan is indicated have ongoing mass treatment programs. In 2005, 42,052,583 treatments of co-administered albendazole and Mectizan were approved for national Programs to Eliminate LF (PELFs) in Africa and Yemen. There are ongoing PELFs using albendazole and Mectizan in nine African countries and Yemen; these represent 35% of the total number of countries expected to require the co-administration of these two chemotherapeutic agents for LF elimination. In Africa, the expansion of existing PELFs and the initiation of new ones have been hampered by lack of resources, technical difficulties with the mapping of LF endemicity, and the co-endemicity of LF and loiasis. Included in this review are recommendations recently put forward for the co-administration of albendazole and Mectizan in areas endemic for LF, loiasis, and onchocerciasis. [ABSTRACT FROM AUTHOR]

Background: The Democratic Republic of the Congo (DRC) experienced atypical outbreaks of wild poliovirus type 1 (WPV1) infection during 2010-2011 in that they affected persons aged ≥15 years in 4 (Bandundu, Bas Congo, Kasaï Occidental, and Kinshasa provinces) of the 6 provinces with outbreaks.Methods: Analyses of cases of WPV1 infection with onset during 2010-2011 by province, age, polio vaccination status, and sex were conducted. The prevalence of antibodies to poliovirus (PV) types 1, 2, and 3 was assessed in sera collected before the outbreaks from women attending antenatal clinics in 3 of the 4 above-mentioned provinces.Results: Of 193 cases of WPV1 infection during 2010-2011, 32 (17%) occurred in individuals aged ≥15 years. Of these 32 cases, 31 (97%) occurred in individuals aged 16-29 years; 9 (28%) were notified in Bandundu, 17 (53%) were notified in Kinshasa, and 22 (69%) had an unknown polio vaccination status. In the seroprevalence assessment, PV type 1 and 3 seroprevalence was lower among women aged 15-29 years in Bandundu and Kinshasa, compared with those in Kasaï Occidental. Seropositivity to PVs was associated with increasing age, more pregnancies, and a younger age at first pregnancy.Conclusions: This spatiotemporal analysis strongly suggests that the 2010-2011 outbreaks of WPV1 infection affecting young adults were caused by a PV type 1 immunity gap in Kinshasa and Bandundu due to insufficient exposure to PV type 1 through natural infection or vaccination. Poliovirus immunity gaps in this age group likely persist in DRC. [ABSTRACT FROM AUTHOR]

In 2022, an estimated 5 million persons in the World Health Organization Region of the Americas (AMR) were living with chronic hepatitis B virus (HBV) infection, the leading cause of hepatocellular carcinoma and cirrhosis worldwide. Most chronic infections are acquired through mother-to-child transmission (MTCT) or horizontal transmission during childhood and are preventable with hepatitis B vaccination, including a birth dose (HepB-BD), followed by 2-3 additional doses (HepB3) in infancy. The Pan American Health Organization (PAHO) Elimination of MTCT of HBV infection strategy is intended to reduce chronic HBV infection (measured by hepatitis B surface antigen [HBsAg] seroprevalence) to ≤0.1% among children by achieving 1) ≥95% coverage with HepB-BD and HepB3; and 2) ≥80% of pregnant women received testing for HBsAg, and provision of hepatitis B immunoglobulin to HBV-exposed neonates. By 2012, all 51 AMR countries and territories (countries) provided HepB3 nationwide, and by 2021, 34 (67%) provided HepB-BD nationwide. Mathematical models estimate that HBsAg seroprevalence in children is ≤0.1% in 14 (28%) of 51 countries and at the regional level. Three (6%) of 51 countries met the 95% coverage targets for both HepB3 and HepB-BD during both 2021 and 2022. Of these, two have likely met criteria for the elimination of MTCT of HBV infection. However, in 2022, HepB3 coverage had declined by ≥10 percentage points in 15 (37%) of 41 countries with 2012 coverage data for comparison. These declines in HepB3 coverage, as well as the absence of HepB-BD in the routine immunization schedules in 17 countries, threaten PAHO's progress toward the elimination of MTCT of HBV infection. Efforts to introduce HepB-BD and maintain high HepB3 and HepB-BD coverage are needed., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Circulating vaccine-derived polioviruses (cVDPVs) can emerge in areas with low poliovirus immunity and cause outbreaks* of paralytic polio (1-5). Among the three types of wild poliovirus, type 2 was declared eradicated in 2015 (1,2). The use of trivalent oral poliovirus vaccine (tOPV; types 1, 2, and 3 Sabin strains) ceased in April 2016 via a 1-month-long, global synchronized switch to bivalent OPV (bOPV; types 1 and 3 Sabin strains) in immunization activities (1-4). Monovalent type 2 OPV (mOPV2; type 2 Sabin strain) is available for cVDPV type 2 (cVDPV2) outbreak response immunization (1-5). The number and geographic breadth of post-switch cVDPV2 outbreaks have exceeded forecasts that trended toward zero outbreaks 4 years after the switch and assumed rapid and effective control of any that occurred (4). New cVDPV2 outbreaks have been seeded by mOPV2 use, by both suboptimal mOPV2 coverage within response zones and recently mOPV2-vaccinated children or contacts traveling outside of response zones, where children born after the global switch are fully susceptible to poliovirus type 2 transmission (2-4). In addition, new emergences can develop by inadvertent exposure to Sabin OPV2-containing vaccine (i.e., residual response mOPV2 or tOPV) (4). This report updates the January 2018-June 2019 report with information on global cVDPV outbreaks during July 2019-February 2020 (as of March 25, 2020) † (2). Among 33 cVDPV outbreaks reported during July 2019-February 2020, 31 (94%) were cVDPV2; 18 (58%) of these followed new emergences. In mid-2020, the Global Polio Eradication Initiative (GPEI) plans to introduce a genetically stabilized, novel OPV type 2 (nOPV2) that has a lower risk for generating VDPV2 than does Sabin mOPV2; if nOPV2 is successful in limiting new VDPV2 emergences, GPEI foresees the replacement of Sabin mOPV2 with nOPV2 for cVDPV2 outbreak responses during 2021 (2,4,6)., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Widespread use of live attenuated (Sabin) oral poliovirus vaccine (OPV) has resulted in marked progress toward global poliomyelitis eradication (1). However, in underimmunized populations, extensive person-to-person transmission of Sabin poliovirus can result in genetic reversion to neurovirulence and paralytic vaccine-derived poliovirus (VDPV) disease (1). This report updates (as of February 26, 2019) previous reports on circulating VDPV type 2 (cVDPV2) outbreaks during 2017-2018 in the Democratic Republic of the Congo (DRC) and in Somalia, which experienced a concurrent cVDPV type 3 (cVDPV3) outbreak* (2,3). In DRC, 42 cases have been reported in four cVDPV2 outbreaks; paralysis onset in the most recent case was October 7, 2018 (2). Challenges to interrupting transmission have included delays in outbreak-response supplementary immunization activities (SIAs) and difficulty reaching children in all areas. In Somalia, cVDPV2 and cVDPV3 were detected in sewage before the detection of paralytic cases (3). Twelve type 2 and type 3 cVDPV cases have been confirmed; the most recent paralysis onset dates were September 2 (cVDPV2) and September 7, 2018 (cVDPV3). The primary challenge to interrupting transmission is the residence of >300,000 children in areas that are inaccessible for vaccination activities. For both countries, longer periods of surveillance are needed before interruption of cVDPV transmission can be inferred., Competing Interests: All authors have completed and submitted the ICMJE form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

The last confirmed wild poliovirus (WPV) case in Democratic Republic of the Congo (DRC) had paralysis onset in December 2011 (1). DRC has had cases of vaccine-derived polioviruses (VDPVs) documented since 2004 (Table 1) (1-6). After an outbreak of 30 circulating VDPV type 2 (cVDPV2) cases during 2011-2012, only five VDPV2 cases were reported during 2013-2016 (Table 1) (1-6). VDPVs can emerge from oral poliovirus vaccine (OPV types 1, 2, or 3; Sabin) polioviruses that have genetically mutated resulting in reversion to neurovirulence. This process occurs during extensive person-to-person transmission in populations with low immunity or after extended replication in the intestines of immune-deficient persons following vaccination (1-6). During 2017 (as of March 8, 2018), 25 VDPV cases were reported in three provinces in DRC: in Tanganyika province, an emergence with one VDPV2 case (pending final classification) in Kabalo health zone and an emergence with one ambiguous VDPV type 1 (aVDPV1) case in Ankoro health zone; in Maniema province, an emergence with two cVDPV2 cases; and in Haut Lomami province, an emergence with 20 cVDPV2 cases that originated in Haut Lomami province and later spread to Tanganyika province (hereafter referred to as the Haut Lomami outbreak area) and an emergence with one aVDPV type 2 (aVDPV2) case in Lwamba health zone (Table 1) (Figure) (6). Outbreak response supplementary immunization activities (SIAs) were conducted during June-December 2017 (Table 2) (6). Because of limitations in surveillance and suboptimal SIA quality and geographic scope, cVDPV2 circulation is likely continuing in 2018, requiring additional SIAs. DRC health officials and Global Polio Eradication Initiative (GPEI) partners are increasing human and financial resources to improve all aspects of outbreak response., Competing Interests: No conflicts of interest were reported.