Last data update: May 20, 2024. (Total: 46824 publications since 2009)
Records 1-8 (of 8 Records) |
Query Trace: Paluku G [original query] |
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Progress toward Hepatitis B control and elimination of mother-to-child transmission of Hepatitis B virus - World Health Organization African Region, 2016-2021
Kabore HJ , Li X , Alleman MM , Manzengo CM , Mumba M , Biey J , Paluku G , Bwaka AM , Impouma B , Tohme RA . MMWR Morb Mortal Wkly Rep 2023 72 (29) 782-787 Chronic hepatitis B virus (HBV) infection is one of the leading causes of cirrhosis and liver cancer. In 2019, approximately 1.5 million persons newly acquired chronic HBV infection; among these, 990,000 (66%) were in the World Health Organization (WHO) African Region (AFR). Most chronic HBV infections are acquired through mother-to-child transmission (MTCT) or during early childhood, and approximately two thirds of these infections occur in AFR. In 2016, the World Health Assembly endorsed the goal of elimination of mother-to-child transmission (EMTCT) of HBV, documented by ≥90% coverage with both a timely hepatitis B vaccine (HepB) birth dose (HepB-BD) and 3 infant doses of HepB (HepB3), and ≤0.1% hepatitis B surface antigen (HBsAg) seroprevalence among children aged ≤5 years. In 2016, the WHO African Regional Committee endorsed targets for a 30% reduction in incidence (≤2% HBsAg seroprevalence in children aged ≤5 years) and ≥90% HepB3 coverage by 2020. By 2021, all 47 countries in the region provided HepB3 to infants beginning at age 6 weeks, and 14 countries (30%) provided HepB-BD. By December 2021, 16 (34%) countries achieved ≥90% HepB3 coverage, and only two (4%) achieved ≥90% timely HepB-BD coverage. Eight countries (17%) conducted nationwide serosurveys among children born after the introduction of HepB to assess HBsAg seroprevalence: six countries had achieved ≤2% seroprevalence, but none had achieved ≤0.1% seroprevalence among children. The development of immunization recovery plans following the COVID-19 pandemic provides an opportunity to accelerate progress toward hepatitis B control and EMTCT, including introducing HepB-BD and increasing coverage with timely HepB-BD and HepB3 vaccination. Representative HBsAg serosurveys among children and a regional verification body for EMTCT of HBV will be needed to monitor progress. |
Use of a rapid digital microfluidics-powered immunoassay for assessing measles and rubella infection and immunity in outbreak settings in the Democratic Republic of the Congo
Knipes AK , Summers A , Sklavounos AA , Lamanna J , de Campos RPS , Narahari T , Dixon C , Fobel R , Ndjakani YD , Lubula L , Magazani A , Muyembe JJ , Lay Y , Pukuta E , Waku-Kouomou D , Hao L , Kayembe JK , Fobel C , Dahmer J , Lee A , Ho M , Valenzuela JGC , Rackus DG , Shih R , Seale B , Chang A , Paluku G , Rota PA , Wheeler AR , Scobie HM . PLoS One 2022 17 (12) e0278749 The Democratic Republic of the Congo (DRC) has a high measles incidence despite elimination efforts and has yet to introduce rubella vaccine. We evaluated the performance of a prototype rapid digital microfluidics powered (DMF) enzyme-linked immunoassay (ELISA) assessing measles and rubella infection, by testing for immunoglobulin M (IgM), and immunity from natural infection or vaccine, by testing immunoglobulin G (IgG), in outbreak settings. Field evaluations were conducted during September 2017, in Kinshasa province, DRC. Blood specimens were collected during an outbreak investigation of suspected measles cases and tested for measles and rubella IgM and IgG using the DMF-ELISA in the field. Simultaneously, a household serosurvey for measles and rubella IgG was conducted in a recently confirmed measles outbreak area. DMF-ELISA results were compared with reference ELISA results tested at DRC's National Public Health Laboratory and the US Centers for Disease Control and Prevention. Of 157 suspected measles cases, rubella IgM was detected in 54% while measles IgM was detected in 13%. Measles IgG-positive cases were higher among vaccinated persons (87%) than unvaccinated persons (72%). In the recent measles outbreak area, measles IgG seroprevalence was 93% overall, while rubella seroprevalence was lower for children (77%) than women (98%). Compared with reference ELISA, DMF-ELISA sensitivity and specificity were 82% and 78% for measles IgG; 88% and 89% for measles IgM; 85% and 85% for rubella IgG; and 81% and 83% for rubella IgM, respectively. Rubella infection was detected in more than half of persons meeting the suspected measles case definition during a presumed measles outbreak, suggesting substantial unrecognized rubella incidence, and highlighting the need for rubella vaccine introduction into the national schedule. The performance of the DMF-ELISA suggested that this technology can be used to develop rapid diagnostic tests for measles and rubella. |
Epidemiology and pre-vaccine burden of rotavirus diarrhea in Democratic Republic of Congo (DRC): Results of sentinel surveillance, 2009-2019.
Luhata Lungayo C , Burke RM , Cikomola A , Mukamba E , Burnett E , Tate JE , Samuel Otomba J , Albert MK , Nimpa MM , Dommergues MA , Pukuta E , Mwenda JM , Shaba K , Paluku GK , N'Diaye A , Ditekemena J , Launay O , Jouffroy R . Vaccine 2022 40 (41) 5933-5941 INTRODUCTION: Since August 2009, the Democratic Republic of Congo (DRC) has implemented sentinel site surveillance for rotavirus gastroenteritis. Limited hospital studies have been carried out, in DRC, describing the epidemiology of rotavirus diarrhea before rotavirus vaccine introduction in October 2019. This analysis describes the epidemiology of rotavirus gastroenteritis and characteristics of circulating viral strains from 2009 to 2019. MATERIALS AND METHODS: We analyzed demographic and clinic data collected from children < 5 years old enrolled at three rotavirus sentinel surveillance sites in DRC during 2009-2019, prior to rotavirus vaccine introduction in 2019. Data have been described and presented as mean ± standard deviation for quantitative variables with normal distribution, or as median with an interquartile range [Q1-Q3] for quantitative variables with non-normal distribution, or as absolute value with percentage for qualitative variables. RESULTS: Between August 2009 and December 2019, 4,928 children < 5 years old were admitted to sentinel surveillance sites for gastroenteritis in the DRC; the rotavirus positivity rate was 60 %. There was a slight male gender predominance (56 %), and the majority of children (79 %) were 0-11 months of age. Every year, the incidence was highest between May and September corresponding to the dry and cool season. Genotyping was performed for 50 % of confirmed rotavirus cases. The most common G genotypes were G1 (39 %) and G2 (24 %) and most common P genotypes were P[6] (49 %) and P[8] (37 %). The most common G-P genotype combinations were G1P[8] (22 %), G2P[6] (16 %) and G1P[6] (14 %). Genotype distribution varied by site, age group, and year. CONCLUSION: From 2009 to 2019, rotavirus-associated gastroenteritis represented a significant burden among DRC children under 5 who were admitted to sentinel sites. G1P[8] was the most commonly identified genotype. Continued monitoring after the introduction of rotavirus vaccine will be essential to monitor any changes in epidemiology. |
Impact of rotavirus vaccine introduction on rotavirus hospitalizations among children under 5 years of age - World Health Organization African Region, 2008-2018
Mwenda JM , Hallowell BD , Parashar U , Shaba K , Biey JN , Weldegebriel GG , Paluku GK , Ntsama B , N'Diaye A , Bello IM , Bwaka AM , Zawaira FR , Mihigo R , Tate JE . Clin Infect Dis 2021 73 (9) 1605-1608 BACKGROUND: Rotavirus is the leading cause of acute gastroenteritis (AGE) among children worldwide. Prior to rotavirus vaccine introduction, over one third of AGE hospitalizations in Africa were due to rotavirus. We describe the impact of rotavirus vaccines using data from the African Rotavirus Surveillance Network (ARSN). METHODS: For descriptive analysis, we included all sites reporting to ARSN for any length of time between 2008-2018. For vaccine impact analysis, continuous surveillance throughout the year was required to minimize potential bias due to enrollment of partial seasons and sites had to report a minimum of 100 AGE cases per year. We report the proportion of rotavirus AGE cases by year relative to vaccine introduction, and the relative reduction in the proportion of rotavirus AGE cases reported following vaccine introduction. RESULTS: From 2008-2018, 97,366 prospectively enrolled hospitalized children <5 years of age met the case definition for AGE, and 34.1% tested positive for rotavirus. Among countries that had introduced rotavirus vaccine, the proportion of hospitalized AGE cases positive for rotavirus declined from 39.2% in the pre-vaccine period to 25.3% in the post-vaccine period, a 35.5% (95% CI: 33.7-37.3) decline. No declines were observed among countries that had not introduced the vaccine over the 11-year period. CONCLUSION: Rotavirus vaccine introduction led to large and consistent declines in the proportion of hospitalized AGE cases that are positive for rotavirus. To maximize the public health benefit of these vaccines, efforts to introduce rotavirus vaccines to the remaining countries in the region and improve coverage should continue. |
Immunogenicity of fractional-dose vaccine during a yellow fever outbreak - final report
Casey RM , Harris JB , Ahuka-Mundeke S , Dixon MG , Kizito GM , Nsele PM , Umutesi G , Laven J , Kosoy O , Paluku G , Gueye AS , Hyde TB , Ewetola R , Sheria GKM , Muyembe-Tamfum JJ , Staples JE . N Engl J Med 2019 381 (5) 444-454 BACKGROUND: In 2016, the response to a yellow fever outbreak in Angola and the Democratic Republic of Congo led to a global shortage of yellow fever vaccine. As a result, a fractional dose of the 17DD yellow fever vaccine (containing one fifth [0.1 ml] of the standard dose) was offered to 7.6 million children 2 years of age or older and nonpregnant adults in a preemptive campaign in Kinshasa. The goal of this study was to assess the immune response to the fractional dose in a large-scale campaign. METHODS: We recruited participants in four age strata at six vaccination sites. We assessed neutralizing antibody titers against yellow fever virus in blood samples obtained before vaccination and at 1 month and 1 year after vaccination, using a plaque reduction neutralization test with a 50% cutoff (PRNT50). Participants with a PRNT50 titer of 10 or higher were considered to be seropositive. Those with a baseline titer of less than 10 who became seropositive at follow-up were classified as having undergone seroconversion. Participants who were seropositive at baseline and who had an increase in the titer by a factor of 4 or more at follow-up were classified as having an immune response. RESULTS: Among 716 participants who completed the 1-month follow-up, 705 (98%; 95% confidence interval [CI], 97 to 99) were seropositive after vaccination. Among 493 participants who were seronegative at baseline, 482 (98%; 95% CI, 96 to 99) underwent seroconversion. Among 223 participants who were seropositive at baseline, 148 (66%; 95% CI, 60 to 72) had an immune response. Lower baseline titers were associated with a higher probability of having an immune response (P<0.001). Among 684 participants who completed the 1-year follow-up, 666 (97%; 95% CI, 96 to 98) were seropositive for yellow fever antibody. The distribution of titers among the participants who were seronegative for yellow fever antibody at baseline varied significantly among age groups at 1 month and at 1 year (P<0.001 for both comparisons). CONCLUSIONS: A fractional dose of the 17DD yellow fever vaccine was effective at inducing seroconversion in participants who were seronegative at baseline. Titers remained above the threshold for seropositivity at 1 year after vaccination in nearly all participants who were seropositive at 1 month after vaccination. These findings support the use of fractional-dose vaccination for outbreak control. (Funded by the U.S. Agency for International Development and the Centers for Disease Control and Prevention.). |
Immunogenicity of fractional-dose vaccine during a yellow fever outbreak - preliminary report
Ahuka-Mundeke S , Casey RM , Harris JB , Dixon MG , Nsele PM , Kizito GM , Umutesi G , Laven J , Paluku G , Gueye AS , Hyde TB , Sheria GKM , Muyembe-Tanfum JJ , Staples JE . N Engl J Med 2018 381 (5) 444-454 Background In 2016, the response to a yellow fever outbreak in Angola and the Democratic Republic of Congo led to a global shortage of yellow fever vaccine. As a result, a fractional dose of the 17DD yellow fever vaccine (containing one fifth [0.1 ml] of the standard dose) was offered to 7.6 million children 2 years of age or older and nonpregnant adults in a preemptive campaign in Kinshasa. The goal of this study was to assess the immune response to the fractional dose in a large-scale campaign. Methods We recruited participants in four age strata at six vaccination sites. We assessed neutralizing antibody titers against yellow fever virus in blood samples obtained before vaccination and 28 to 35 days after vaccination, using a plaque reduction neutralization test with a 50% cutoff (PRNT50). Participants with a PRNT50 titer of 10 or higher at baseline were considered to be seropositive. Those with a baseline titer of less than 10 who became seropositive at follow-up were classified as having undergone seroconversion. Participants who were seropositive at baseline and who had an increase in the titer by a factor of 4 or more at follow-up were classified as having an immune response. Results Among 716 participants who completed follow-up, 705 (98%; 95% confidence interval [CI], 97 to 99) were seropositive after vaccination. Among 493 participants who were seronegative at baseline, 482 (98%; 95% CI, 96 to 99) underwent seroconversion. Among 223 participants who were seropositive at baseline, 148 (66%; 95% CI, 60 to 72) had an immune response. Lower baseline titers were associated with a higher probability of having an immune response (P<0.001). Conclusions A fractional dose of the 17DD yellow fever vaccine was effective at inducing seroconversion in most of the participants who were seronegative at baseline. These findings support the use of fractional-dose vaccination for outbreak control. (Funded by the U.S. Agency for International Development and the Centers for Disease Control and Prevention.). |
Expansion of vaccination services and strengthening vaccine-preventable diseases surveillance in Haiti, 2010-2016
Tohme RA , Francois J , Cavallaro KF , Paluku G , Yalcouye I , Jackson E , Wright T , Adrien P , Katz MA , Hyde TB , Faye P , Kimanuka F , Dietz V , Vertefeuille J , Lowrance D , Dahl B , Patel R . Am J Trop Med Hyg 2017 97 28-36 Following the 2010 earthquake, Haiti was at heightened risk for vaccine-preventable diseases (VPDs) outbreaks due to the exacerbation of long-standing gaps in the vaccination program and subsequent risk of VPD importation from other countries. Therefore, partners supported the Haitian Ministry of Health and Population to improve vaccination services and VPD surveillance. During 2010-2016, three polio, measles, and rubella vaccination campaigns were implemented, achieving a coverage > 90% among children and maintaining Haiti free of those VPDs. Furthermore, Haiti is on course to eliminate maternal and neonatal tetanus, with 70% of communes achieving tetanus vaccine two-dose coverage > 80% among women of childbearing age. In addition, the vaccine cold chain storage capacity increased by 91% at the central level and 285% at the department level, enabling the introduction of three new vaccines (pentavalent, rotavirus, and pneumococcal conjugate vaccines) that could prevent an estimated 5,227 deaths annually. Haiti moved from the fourth worst performing country in the Americas in 2012 to the sixth best performing country in 2015 for adequate investigation of suspected measles/rubella cases. Sentinel surveillance sites for rotavirus diarrhea and meningococcal meningitis were established to estimate baseline rates of those diseases prior to vaccine introduction and to evaluate the impact of vaccination in the future. In conclusion, Haiti significantly improved vaccination services and VPD surveillance. However, high dependence on external funding and competing vaccination program priorities are potential threats to sustaining the improvements achieved thus far. Political commitment and favorable economic and legal environments are needed to maintain these gains. |
Seroprevalence of measles and rubella antibodies in pregnant women Haiti, 2012
Fitter DL , Anselme R , Paluku G , Rey G , Flannery B , Tohme RA , Marston BJ , Griswold M , Boncy J , Vertefeuille JF . Vaccine 2013 32 (1) 69-73 BACKGROUND: Haiti had set a national goal to eliminate measles and rubella, as well as congenital rubella syndrome (CRS) by 2010. A 2007-2008 nationwide measles and rubella vaccination campaign targeting 1-19 years, however, reached only 79% of the target population. To assess whether population immunity was adequate to support elimination, we conducted a national serosurvey. METHODS: We systematically selected 740 serum specimens collected from pregnant women in a 2012 national antenatal HIV sentinel serosurvey across four age strata: 15-19, 20-24, 25-29 and 30-39 years. Sera were tested for measles and rubella specific immunoglobulin G antibodies (IgG) using commercial immunoassays. We classified sera as seropositive, seronegative or indeterminate per manufacturer's instructions, and analyzed seroprevalence according to age strata, and rural or urban residence. We assessed immunity by estimating antibody concentrations in international units per milliliter (IU/mL) for seropositive and indeterminate sera. Measles IgG concentrations >0.12IU/mL and rubella IgG concentrations >10IU/mL were considered clinically protective. RESULTS: Of 740 sera, 696 (94.1%) were seropositive and 20 (2.7%) were indeterminate for measles IgG; overall 716 (96.8%) sera had IgG concentrations >0.12IU/mL. For rubella IgG, 691 (93.4%) sera were seropositive and 1 (0.1%) was indeterminate; a total of 687 (92.8%) had IgG concentrations >10IU/mL. Measles seropositivity varied across age strata (p=0.003); seropositivity increased from 88.6% among 15-19 year olds to 98.4% among 30-39 year olds (Cochran-Armitage trend test≤0.0001). Rubella seropositivity did not differ across age strata. There were no statistically significant differences in measles or rubella seropositivity by urban versus rural residence. CONCLUSION: Despite previous low vaccination coverage for measles, results from this serosurvey indicate high levels of measles and rubella seropositivity in pregnant women, and contribute to the evidence for measles, rubella and CRS elimination from Haiti by the target date. |
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