Last data update: Nov 04, 2024. (Total: 48056 publications since 2009)
Records 1-21 (of 21 Records) |
Query Trace: Chard AN[original query] |
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Risk of clade II mpox associated with intimate and nonintimate close contact among men who have sex with men and transgender adults - United States, August 2022-July 2023
Chard AN , Dalton AF , Diallo AO , Moulia DL , Deputy NP , Zecca IB , Quilter LAS , Kachur RE , McCollum AM , Rowlands JV , Britton AN , Fisher R , Chai SJ , Licherdell E , Still WL , Morris AL , Castilho JL , Markus TM , Morrow AS , Danza P , Hansen AP , Ali SI , Wegner CW , Weber R , Betancourt GS , Zipprich J , Sutton M , Pathela P , Hawkins S , Wendel KA , Feldstein LR . MMWR Morb Mortal Wkly Rep 2024 73 (40) 896-902 A global outbreak of clade II mpox associated with sexual contact, disproportionately affecting gay, bisexual, and other men who have sex with men (MSM), has been ongoing since May 2022. Information on types of contact most associated with transmission is limited. This report used data from a multijurisdictional vaccine effectiveness case-control study of sexually active persons aged 18-49 years who identified as MSM or transgender, collected during August 2022-July 2023. Odds of mpox associated with selected types of intimate and nonintimate close contact with a person with mpox were estimated. Among 457 case-patients and 1,030 control patients who met minimum data requirements, 150 (32.8%) case-patients and 57 (5.5%) control patients reported close contact with a person with mpox and were included in this analysis. Adjusted odds of mpox were 5.4 times as high among those who reported having condomless receptive anal sex with a person with mpox, compared with participants who reported close contact with a person with mpox and no condomless receptive anal sex with that person (OR = 5.4; p = 0.031). Although the mpox vaccine is highly effective, vaccination coverage remains low; a multifaceted approach to prevention remains important and should include vaccination promotion, safer sex practices, and increasing awareness that mpox continues to circulate. |
Estimating averted illnesses from influenza vaccination for children and pregnant women - El Salvador, Panama, and Peru, 2011-2018
Chard AN , Machingaidze C , Loayza S , Gharpure R , Nogareda F , González R , Domínguez R , Tinoco YO , Dawood FS , Carreon JD , Lafond KE , Jara J , Azziz-Baumgartner E , Cozza V , Couto P , Rolfes MA , Tempia S . Vaccine 2024 BACKGROUND: Estimating the burden of disease averted by vaccination can assist policymakers to implement, adjust, and communicate the value of vaccination programs. Demonstrating the use of a newly available modeling tool, we estimated the burden of influenza illnesses averted by seasonal influenza vaccination in El Salvador, Panama, and Peru during 2011-2017 among two influenza vaccine target populations: children aged 6-23 months and pregnant women. METHODS: We derived model inputs, including incidence, vaccine coverage, vaccine effectiveness, and multipliers from publicly available country-level influenza surveillance data and cohort studies. We also estimated changes in illnesses averted when countries' vaccine coverage was achieved using four different vaccine deployment strategies. RESULTS: Among children aged 6-23 months, influenza vaccination averted an estimated cumulative 2,161 hospitalizations, 81,907 medically-attended illnesses, and 126,987 overall illnesses during the study period, with a prevented fraction ranging from 0.3 % to 12.5 %. Among pregnant women, influenza vaccination averted an estimated cumulative 173 hospitalizations, 6,122 medically attended illnesses, and 16,412 overall illnesses, with a prevented fraction ranging from 0.2 % to 10.9 %. Compared to an influenza vaccine campaign with equal vaccine distribution during March-June, scenarios in which total cumulative coverage was achieved in March and April consistently resulted in the greatest increase in averted illness (23 %-3,129 % increase among young children and 22 %-3,260 % increase among pregnant women). DISCUSSION: Influenza vaccination campaigns in El Salvador, Panama, and Peru conducted between 2011 and 2018 prevented hundreds to thousands of influenza-associated hospitalizations and illnesses in young children and pregnant women. Existing vaccination programs could prevent additional illnesses, using the same number of vaccines, by achieving the highest possible coverage within the first two months of an influenza vaccine campaign. |
Costs and cost-effectiveness of influenza illness and vaccination in low- and middle-income countries: A systematic review from 2012 to 2022
Gharpure R , Chard AN , Cabrera Escobar M , Zhou W , Valleau MM , Yau TS , Bresee JS , Azziz-Baumgartner E , Pallas SW , Lafond KE . PLoS Med 2024 21 (1) e1004333 BACKGROUND: Historically, lack of data on cost-effectiveness of influenza vaccination has been identified as a barrier to vaccine use in low- and middle-income countries. We conducted a systematic review of economic evaluations describing (1) costs of influenza illness; (2) costs of influenza vaccination programs; and (3) vaccination cost-effectiveness from low- and middle-income countries to assess if gaps persist that could hinder global implementation of influenza vaccination programs. METHODS AND FINDINGS: We performed a systematic search in Medline, Embase, Cochrane Library, CINAHL, and Scopus in January 2022 and October 2023 using a combination of the following key words: "influenza" AND "cost" OR "economic." The search included studies with publication years 2012 through 2022. Studies were eligible if they (1) presented original, peer-reviewed findings on cost of illness, cost of vaccination program, or cost-effectiveness of vaccination for seasonal influenza; and (2) included data for at least 1 low- or middle-income country. We abstracted general study characteristics and data specific to each of the 3 study types. Of 54 included studies, 26 presented data on cost-effectiveness, 24 on cost-of-illness, and 5 on program costs. Represented countries were classified as upper-middle income (UMIC; n = 12), lower-middle income (LMIC; n = 7), and low-income (LIC; n = 3). The most evaluated target groups were children (n = 26 studies), older adults (n = 17), and persons with chronic medical conditions (n = 12); fewer studies evaluated pregnant persons (n = 9), healthcare workers (n = 5), and persons in congregate living settings (n = 1). Costs-of-illness were generally higher in UMICs than in LMICs/LICs; however, the highest national economic burden, as a percent of gross domestic product and national health expenditure, was reported from an LIC. Among studies that evaluated the cost-effectiveness of influenza vaccine introduction, most (88%) interpreted at least 1 scenario per target group as either cost-effective or cost-saving, based on thresholds designated in the study. Key limitations of this work included (1) heterogeneity across included studies; (2) restrictiveness of the inclusion criteria used; and (3) potential for missed influenza burden from use of sentinel surveillance systems. CONCLUSIONS: The 54 studies identified in this review suggest an increased momentum to generate economic evidence about influenza illness and vaccination from low- and middle-income countries during 2012 to 2022. However, given that we observed substantial heterogeneity, continued evaluation of the economic burden of influenza illness and costs/cost-effectiveness of influenza vaccination, particularly in LICs and among underrepresented target groups (e.g., healthcare workers and pregnant persons), is needed. Use of standardized methodology could facilitate pooling across settings and knowledge sharing to strengthen global influenza vaccination programs. |
Costs and cost-effectiveness of influenza illness and vaccination in low- and middle-income countries: A systematic review from 2012 to 2021 (preprint)
Gharpure R , Chard AN , Escobar MC , Zhou W , Bresee JS , Azziz-Baumgartner E , Pallas SW , Lafond KE . medRxiv 2023 08 Introduction: Historically, lack of data on cost-effectiveness of influenza vaccination has been identified as a barrier to vaccine use in low- and middle-income countries. We conducted a systematic review of economic evaluations describing (1) costs of influenza illness, (2) costs of influenza vaccination programs, and (3) vaccination cost-effectiveness from low- and middle-income countries to assess if gaps persist. Method(s): We performed a systematic search in Medline, Embase, Cochrane Library, CINAHL, and Scopus using a combination of the following key words: "influenza" AND "cost" OR "economic." The search included studies with publication years 2012 through 2021. We abstracted general study characteristics and data specific to each of the three areas of review. Result(s): Of 50 included studies, 24 presented data on cost-effectiveness, 23 on cost-of-illness, and four on program costs. Represented countries were classified as upper-middle income (UMIC; n=11), lower-middle income (LMIC; n=7), and low-income (LIC; n=3). The most evaluated target groups were children (n=26 studies), older adults (n=16), and persons with chronic medical conditions (n=12); fewer studies evaluated pregnant persons (n=8), healthcare workers (n=4), and persons in congregate living settings (n=1). Costs-of-illness were generally higher in UMICs than in LMICs/LICs; however, the highest total costs, as a percent of gross domestic product and national health expenditure, were reported from an LIC. Among studies that evaluated the cost-effectiveness of influenza vaccine introduction, most (83%) interpreted at least one scenario per target group as either cost-effective or cost-saving, based on thresholds designated in the study. Conclusion(s): Continued evaluation of the economic burden of influenza illness and costs and cost-effectiveness of influenza vaccination, particularly in low-income countries and among underrepresented target groups (e.g., healthcare workers and pregnant persons), is needed; use of standardized methodology could facilitate pooling across settings. Robust, global economic data are critical to design and maintain sustainable influenza vaccination programs. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license. |
COVID-19 attitudes and vaccine hesitancy among an agricultural community in southwest Guatemala: A cross-sectional survey
Rojop N , Calvimontes DM , Barrios E , Lamb MM , Paniagua-Avila A , Monzon J , Duca LM , Iwamoto C , Chard AN , Gomez M , Arias K , Roell Y , Bolanos GA , Zielinski-Gutierrez E , Azziz-Baumgartner E , Lopez MR , Cordon-Rosales C , Asturias EJ , Olson D . Vaccines (Basel) 2023 11 (6) Despite offering free-of-charge COVID-19 vaccines starting July 2021, Guatemala has one of the lowest vaccination rates in Latin America. From 28 September 2021 to 11 April 2022, we conducted a cross-sectional survey of community members, adapting a CDC questionnaire to evaluate COVID-19 vaccine access and hesitancy. Of 233 participants ≥ 12 years, 127 (55%) received ≥1 dose of COVID-19 and 4 (2%) reported prior COVID-19 illness. Persons ≥ 12 years old who were unvaccinated (n = 106) were more likely to be female (73% vs. 41%, p < 0.001) and homemakers (69% vs. 24%, p < 0.01) compared with vaccinated participants (n = 127). Among those ≥18 years, the main reported motivation for vaccination among vaccinated participants was to protect the health of family/friends (101/117, 86%); on the other hand, 40 (55%) unvaccinated persons reported little/no confidence in public health institutions recommending COVID-19 vaccination. Community- and/or home-based vaccination programs, including vaccination of families through the workplace, may better reach female homemakers and reduce inequities and hesitancy. |
End-of-season influenza vaccine effectiveness during the Southern Hemisphere 2022 Influenza Season - Chile, Paraguay, and Uruguay
Chard AN , Nogareda F , Regan AK , Barraza MFO , Fasce RA , Vergara N , Avendaño M , Penayo E , Vázquez C , Von Horoch M , Michel F , Alfonso A , Mogdasy C , Chiparelli H , Goñi N , Alegretti M , Loayza S , Couto P , Rodriguez A , Salas D , Fowlkes AL , Azziz-Baumgartner E . Int J Infect Dis 2023 134 39-44 OBJECTIVE: To estimate the 2022 end-of-season influenza vaccine effectiveness (VE) against severe acute respiratory illness (SARI) hospitalization in Chile, Paraguay, and Uruguay. METHODS: We pooled surveillance data from SARI cases in 18 sentinel surveillance hospitals in Chile (n=9), Paraguay (n=2), and Uruguay (n=7) during March 16-November 30, 2022. VE was estimated using a test-negative design and logistic regression models adjusted for country, age, sex, presence of ≥1 comorbidity, and week of illness onset. VE estimates were stratified by influenza virus type and subtype (when available) and influenza vaccine target population, categorized as children, individuals with comorbidities, and older adults, defined per countries' national immunization policies. RESULTS: Among the 3,147 SARI cases, there were 382 (12.1%) influenza test-positive case-patients; 328 (85.9%) influenza case-patients were in Chile, 33 (8.6%) were in Paraguay, and 21 (5.5%) were in Uruguay. In all countries, the predominant subtype was influenza A(H3N2) (92.6% of influenza cases). Adjusted VE against any influenza-associated SARI hospitalization was 33.8% (95% CI: 15.3%, 48.2%); VE against influenza A(H3N2)-associated SARI hospitalization was 30.4% (95% CI: 10.1%, 46.0%). VE estimates were similar across target populations. CONCLUSION: During the 2022 influenza season, influenza vaccination reduced the odds of hospitalization among those vaccinated by one-third. Health officials should encourage influenza vaccination in accordance with national recommendations. |
Estimated effectiveness of JYNNEOS vaccine in preventing Mpox: A Multijurisdictional Case-Control Study - United States, August 19, 2022-March 31, 2023
Dalton AF , Diallo AO , Chard AN , Moulia DL , Deputy NP , Fothergill A , Kracalik I , Wegner CW , Markus TM , Pathela P , Still WL , Hawkins S , Mangla AT , Ravi N , Licherdell E , Britton A , Lynfield R , Sutton M , Hansen AP , Betancourt GS , Rowlands JV , Chai SJ , Fisher R , Danza P , Farley M , Zipprich J , Prahl G , Wendel KA , Niccolai L , Castilho JL , Payne DC , Cohn AC , Feldstein LR . MMWR Morb Mortal Wkly Rep 2023 72 (20) 553-558 As of March 31, 2023, more than 30,000 monkeypox (mpox) cases had been reported in the United States in an outbreak that has disproportionately affected gay, bisexual, and other men who have sex with men (MSM) and transgender persons (1). JYNNEOS vaccine (Modified Vaccinia Ankara vaccine, Bavarian Nordic) was approved by the Food and Drug Administration (FDA) in 2019 for the prevention of smallpox and mpox via subcutaneous injection as a 2-dose series (0.5 mL per dose, administered 4 weeks apart) (2). To expand vaccine access, an Emergency Use Authorization was issued by FDA on August 9, 2022, for dose-sparing intradermal injection of JYNNEOS as a 2-dose series (0.1 mL per dose, administered 4 weeks apart) (3). Vaccination was available to persons with known or presumed exposure to a person with mpox (postexposure prophylaxis [PEP]), as well as persons at increased risk for mpox or who might benefit from vaccination (preexposure mpox prophylaxis [PrEP]) (4). Because information on JYNNEOS vaccine effectiveness (VE) is limited, a matched case-control study was conducted in 12 U.S. jurisdictions,(†) including nine Emerging Infections Program sites and three Epidemiology and Laboratory Capacity sites,(§) to evaluate VE against mpox among MSM and transgender adults aged 18-49 years. During August 19, 2022-March 31, 2023, a total of 309 case-patients were matched to 608 control patients. Adjusted VE was 75.2% (95% CI = 61.2% to 84.2%) for partial vaccination (1 dose) and 85.9% (95% CI = 73.8% to 92.4%) for full vaccination (2 doses). Adjusted VE for full vaccination by subcutaneous, intradermal, and heterologous routes of administration was 88.9% (95% CI = 56.0% to 97.2%), 80.3% (95% CI = 22.9% to 95.0%), and 86.9% (95% CI = 69.1% to 94.5%), respectively. Adjusted VE for full vaccination among immunocompromised participants was 70.2% (95% CI = -37.9% to 93.6%) and among immunocompetent participants was 87.8% (95% CI = 57.5% to 96.5%). JYNNEOS is effective at reducing the risk for mpox. Because duration of protection of 1 versus 2 doses remains unknown, persons at increased risk for mpox exposure should receive the 2-dose series as recommended by the Advisory Committee on Immunization Practices (ACIP),(¶) regardless of administration route or immunocompromise status. |
Vaccine effectiveness of JYNNEOS against mpox disease in the United States
Deputy NP , Deckert J , Chard AN , Sandberg N , Moulia DL , Barkley E , Dalton AF , Sweet C , Cohn AC , Little DR , Cohen AL , Sandmann D , Payne DC , Gerhart JL , Feldstein LR . N Engl J Med 2023 388 (26) 2434-2443 BACKGROUND: In the United States, more than 30,000 cases of mpox (formerly known as monkeypox) had occurred as of March 1, 2023, in an outbreak disproportionately affecting transgender persons and gay, bisexual, and other men who have sex with men. In 2019, the JYNNEOS vaccine was approved for subcutaneous administration (0.5 ml per dose) to prevent mpox infection. On August 9, 2022, an emergency use authorization was issued for intradermal administration (0.1 ml per dose); however, real-world effectiveness data are limited for either route. METHODS: We conducted a case-control study based on data from Cosmos, a nationwide Epic electronic health record (EHR) database, to assess the effectiveness of JYNNEOS vaccination in preventing medically attended mpox disease among adults. Case patients had an mpox diagnosis code or positive orthopoxvirus or mpox virus laboratory result, and control patients had an incident diagnosis of human immunodeficiency virus (HIV) infection or a new or refill order for preexposure prophylaxis against HIV infection between August 15, 2022, and November 19, 2022. Odds ratios and 95% confidence intervals were estimated from conditional logistic-regression models, adjusted for confounders; vaccine effectiveness was calculated as (1 - odds ratio for vaccination in case patients vs. controls) × 100. RESULTS: Among 2193 case patients and 8319 control patients, 25 case patients and 335 control patients received two doses (full vaccination), among whom the estimated adjusted vaccine effectiveness was 66.0% (95% confidence interval [CI], 47.4 to 78.1), and 146 case patients and 1000 control patients received one dose (partial vaccination), among whom the estimated adjusted vaccine effectiveness was 35.8% (95% CI, 22.1 to 47.1). CONCLUSIONS: In this study using nationwide EHR data, patients with mpox were less likely to have received one or two doses of JYNNEOS vaccine than control patients. The findings suggest that JYNNEOS vaccine was effective in preventing mpox disease, and a two-dose series appeared to provide better protection. (Funded by the Centers for Disease Control and Prevention and Epic Research.). |
Spatiotemporal variation in risk of Shigella infection in childhood: a global risk mapping and prediction model using individual participant data
Badr HS , Colston JM , Nguyen NH , Chen YT , Burnett E , Ali SA , Rayamajhi A , Satter SM , Van Trang N , Eibach D , Krumkamp R , May J , Adegnika AA , Manouana GP , Kremsner PG , Chilengi R , Hatyoka L , Debes AK , Ateudjieu J , Faruque ASG , Hossain MJ , Kanungo S , Kotloff KL , Mandomando I , Nisar MI , Omore R , Sow SO , Zaidi AKM , Lambrecht N , Adu B , Page N , Platts-Mills JA , Mavacala Freitas C , Pelkonen T , Ashorn P , Maleta K , Ahmed T , Bessong P , Bhutta ZA , Mason C , Mduma E , Olortegui MP , Peñataro Yori P , Lima AAM , Kang G , Humphrey J , Ntozini R , Prendergast AJ , Okada K , Wongboot W , Langeland N , Moyo SJ , Gaensbauer J , Melgar M , Freeman M , Chard AN , Thongpaseuth V , Houpt E , Zaitchik BF , Kosek MN . Lancet Glob Health 2023 11 (3) e373-e384 BACKGROUND: Diarrhoeal disease is a leading cause of childhood illness and death globally, and Shigella is a major aetiological contributor for which a vaccine might soon be available. The primary objective of this study was to model the spatiotemporal variation in paediatric Shigella infection and map its predicted prevalence across low-income and middle-income countries (LMICs). METHODS: Individual participant data for Shigella positivity in stool samples were sourced from multiple LMIC-based studies of children aged 59 months or younger. Covariates included household-level and participant-level factors ascertained by study investigators and environmental and hydrometeorological variables extracted from various data products at georeferenced child locations. Multivariate models were fitted and prevalence predictions obtained by syndrome and age stratum. FINDINGS: 20 studies from 23 countries (including locations in Central America and South America, sub-Saharan Africa, and south and southeast Asia) contributed 66 563 sample results. Age, symptom status, and study design contributed most to model performance followed by temperature, wind speed, relative humidity, and soil moisture. Probability of Shigella infection exceeded 20% when both precipitation and soil moisture were above average and had a 43% peak in uncomplicated diarrhoea cases at 33°C temperatures, above which it decreased. Compared with unimproved sanitation, improved sanitation decreased the odds of Shigella infection by 19% (odds ratio [OR]=0·81 [95% CI 0·76-0·86]) and open defecation decreased them by 18% (OR=0·82 [0·76-0·88]). INTERPRETATION: The distribution of Shigella is more sensitive to climatological factors, such as temperature, than previously recognised. Conditions in much of sub-Saharan Africa are particularly propitious for Shigella transmission, although hotspots also occur in South America and Central America, the Ganges-Brahmaputra Delta, and the island of New Guinea. These findings can inform prioritisation of populations for future vaccine trials and campaigns. FUNDING: NASA, National Institutes of Health-The National Institute of Allergy and Infectious Diseases, and Bill & Melinda Gates Foundation. |
Clinical and economic impact of COVID-19 on agricultural workers, Guatemala
Olson D , Calvimontes DM , Lamb MM , Guzman G , Barrios E , Chacon A , Rojop N , Arias K , Gomez M , Bolanos GA , Monzon J , Chard AN , Iwamoto C , Duca LM , Vuong N , Fineman M , Lesteberg K , Beckham D , Santiago ML , Quicke K , Ebel G , Gutierrez EZ , Azziz-Baumgartner E , Hayden FG , Mansour H , Edwards K , Newman LS , Asturias EJ . Emerg Infect Dis 2022 28 (13) S277-s287 We evaluated clinical and socioeconomic burdens of respiratory disease in banana farm workers in Guatemala. We offered all eligible workers enrollment during June 15-December 30, 2020, and annually, then tracked them for influenza-like illnesses (ILI) through self-reporting to study nurses, sentinel surveillance at health posts, and absenteeism. Workers who had ILI submitted nasopharyngeal swab specimens for testing for influenza virus, respiratory syncytial virus, and SARS-CoV-2, then completed surveys at days 0, 7, and 28. Through October 10, 2021, a total of 1,833 workers reported 169 ILIs (12.0 cases/100 person-years), and 43 (25.4%) were laboratory-confirmed infections with SARS-CoV-2 (3.1 cases/100 person-years). Workers who had SARS-CoV-2positive ILIs reported more frequent anosmia, dysgeusia, difficulty concentrating, and irritability and worse clinical and well-being severity scores than workers who had test resultnegative ILIs. Workers who had positive results also had greater absenteeism and lost income. These results support prioritization of farm workers in Guatemala for COVID-19 vaccination. |
Influenza incidence and vaccine effectiveness during the Southern Hemisphere influenza season - Chile, 2022
Olivares Barraza MF , Fasce RA , Nogareda F , Marcenac P , Vergara Mallegas N , Bustos Alister P , Loayza S , Chard AN , Arriola CS , Couto P , García Calavaro C , Rodriguez A , Wentworth DE , Cuadrado C , Azziz-Baumgartner E . MMWR Morb Mortal Wkly Rep 2022 71 (43) 1353-1358 The COVID-19 pandemic has affected influenza virus transmission, with historically low activity, atypical timing, or altered duration of influenza seasons during 2020-22 (1,2). Community mitigation measures implemented since 2020, including physical distancing and face mask use, have, in part, been credited for low influenza detections globally during the pandemic, compared with those during prepandemic seasons (1). Reduced population exposure to natural influenza infections during 2020-21 and relaxed community mitigation measures after introduction of COVID-19 vaccines could increase the possibility of severe influenza epidemics. Partners in Chile and the United States assessed Southern Hemisphere influenza activity and estimated age-group-specific rates of influenza-attributable hospitalizations and vaccine effectiveness (VE) in Chile in 2022. Chile's most recent influenza season began in January 2022, which was earlier than during prepandemic seasons and was associated predominantly with influenza A(H3N2) virus, clade 3C.2a1b.2a.2. The cumulative incidence of influenza-attributable pneumonia and influenza (P&I) hospitalizations was 5.1 per 100,000 person-years during 2022, which was higher than that during 2020-21 but lower than incidence during the 2017-19 influenza seasons. Adjusted VE against influenza A(H3N2)-associated hospitalization was 49%. These findings indicate that influenza activity continues to be disrupted after emergence of SARS-CoV-2 in 2020. Northern Hemisphere countries might benefit from preparing for an atypical influenza season, which could include early influenza activity with potentially severe disease during the 2022-23 season, especially in the absence of prevention measures, including vaccination. Health authorities should encourage all eligible persons to seek influenza vaccination and take precautions to reduce transmission of influenza (e.g., avoiding close contact with persons who are ill). |
High SARS-CoV-2 Seroprevalence and Rapid Neutralizing Antibody Decline among Agricultural Workers in Rural Guatemala, June 2020-March 2021.
Iwamoto C , Lesteberg KE , Lamb MM , Calvimontes DM , Guo K , Barrett BS , Mickens KL , Duca LM , Monzon J , Chard AN , Guzman G , Barrios E , Rojop N , Arias K , Gomez M , Paiz C , Bolanos GA , Edwards KM , Zielinski Gutierrez E , Azziz-Baumgartner E , Asturias EJ , Santiago ML , Beckham JD , Olson D . Vaccines (Basel) 2022 10 (7) Essential agricultural workers work under occupational conditions that may increase the risk of SARS-CoV-2 exposure and transmission. Data from an agricultural worker cohort in Guatemala, and anti-SARS-CoV-2 nucleocapsid IgG (anti-N IgG) testing were used to estimate past infections and analyze risk factors associated with seropositivity at enrollment and association with SARS-CoV-2 infection. The stability of neutralizing antibody (NAb) responses were assessed in a subset of participants. The adjusted relative risk (aRR) for seroprevalence at enrollment was estimated accounting for correlations within worksites. At enrollment, 616 (46.2%) of 1334 (93.2%) participants had anti-N IgG results indicating prior SARS-CoV-2 infection. A cough ≤ 10 days prior to enrollment (aRR = 1.28, 95% CI: 1.13-1.46) and working as a packer (aRR = 2.00, 95% CI: 1.67-2.38) or packing manager within the plants (aRR = 1.82, 95% CI: 1.36-2.43) were associated with increased risk of seropositivity. COVID-19 incidence density among seronegative workers was 2.3/100 Person-Years (P-Y), higher than seropositive workers (0.4/100 P-Y). Most workers with follow-up NAb testing (65/77, 84%) exhibited a 95% average decrease in NAb titers in <6 months. While participants seropositive at baseline were less likely to experience a symptomatic SARS-CoV-2 infection during follow-up, NAb titers rapidly waned, underscoring the need for multipronged COVID-19 prevention strategies in the workplace, including vaccination. |
Estimation of oral poliovirus vaccine effectiveness in Afghanistan, 2010-2020
Chard AN , Martinez M , Matanock A , Kassem AM . Vaccine 2021 39 (42) 6250-6255 BACKGROUND: Afghanistan is one of two countries with endemic wild poliovirus type 1 (WPV1). The oral poliovirus vaccine (OPV) is the predominant vaccine used for polio eradication. Although OPV has been administered in routine childhood immunization and during frequent supplementary immunization activities, WPV1 continues to circulate in Afghanistan and case incidence has been increasing since 2017. We estimated the effectiveness of OPV in Afghanistan during 2010-2020. METHODS: We conducted a matched case-control analysis using acute flaccid paralysis (AFP) surveillance data from 29,370 children < 15 years with AFP onset between January 1, 2010 and December 31, 2020. We matched children with confirmed WPV1 (cases) with children with non-polio AFP (controls) by age at onset of paralysis (+/- 3 months), date of onset of paralysis (+/- 3 months), and province of residence, and compared their reported OPV vaccination history to estimate the effectiveness of OPV in preventing paralysis by WPV1 using conditional logistic regression. To account for changes in OPV formulations provided over the analysis period, we stratified the analysis based on dates of the global switch from trivalent OPV (tOPV) to bivalent OPV (bOPV) in April 2016. RESULTS: Between January 1, 2010 and December 31, 2020, there were 329 WPV1 cases in Afghanistan. The per-dose estimated effectiveness of OPV against WPV1 was 19% (95% CI: 15%-22%) and of ≥ 7 doses was 94% (95% CI: 90%-97%). Before the global switch from tOPV to bOPV, the per-dose estimated effectiveness of OPV was 14% (95% CI: 11%-18%) and of ≥ 7 doses was 92% (95% CI: 85%-96%). After the switch, the per-dose estimated effectiveness of OPV against WPV1 was 32% (24%-39%) and of ≥ 7 doses was 96% (95% CI: 90%-99%). DISCUSSION: OPV is highly effective in preventing paralysis by WPV1; these results indicate that continued WPV1 transmission in Afghanistan is due to failure to vaccinate, not failure of the vaccine. Although difficult to implement in parts of country, improving the administration of OPV in routine immunization and supplementary immunization activities will be critical for achieving polio eradication in Afghanistan. |
Use of Stay-at-Home Orders and Mask Mandates to Control COVID-19 Transmission - Blackfeet Tribal Reservation, Montana, June-December 2020.
Pratt CQ , Chard AN , LaPine R , Galbreath KW , Crawford C , Plant A , Stiffarm G , Rhodes NS , Hannon L , Dinh TH . MMWR Morb Mortal Wkly Rep 2021 70 (14) 514-518 COVID-19 has disproportionately affected persons who identify as non-Hispanic American Indian or Alaska Native (AI/AN) (1). The Blackfeet Tribal Reservation, the northern Montana home of the sovereign Blackfeet Nation, with an estimated population of 10,629 (2), detected the first COVID-19 case in the community on June 16, 2020. Following CDC guidance,* and with free testing widely available, the Indian Health Service and Blackfeet Tribal Health Department began investigating all confirmed cases and their contacts on June 25. The relationship between three community mitigation resolutions passed and enforced by the Blackfeet Tribal Business Council and changes in the daily COVID-19 incidence and in the distributions of new cases was assessed. After the September 28 issuance of a strictly enforced stay-at-home order and adoption of a mask use resolution, COVID-19 incidence in the Blackfeet Tribal Reservation decreased by a factor of 33 from its peak of 6.40 cases per 1,000 residents per day on October 5 to 0.19 on November 7. Other mitigation measures the Blackfeet Tribal Reservation used included closing the east gate of Glacier National Park for the summer tourism season, instituting remote learning for public school students throughout the fall semester, and providing a Thanksgiving meal to every household to reduce trips to grocery stores. CDC has recommended use of routine public health interventions for infectious diseases, including case investigation with prompt isolation, contact tracing, and immediate quarantine after exposure to prevent and control transmission of SARS-CoV-2, the virus that causes COVID-19 (3). Stay-at-home orders, physical distancing, and mask wearing indoors, outdoors when physical distancing is not possible, or when in close contact with infected or exposed persons are also recommended as nonpharmaceutical community mitigation measures (3,4). Implementation and strict enforcement of stay-at-home orders and a mask use mandate likely helped reduce the spread of COVID-19 in the Blackfeet Tribal Reservation. |
Screening for SARS-CoV-2 Infection Within a Psychiatric Hospital and Considerations for Limiting Transmission Within Residential Psychiatric Facilities - Wyoming, 2020.
Callaghan AW , Chard AN , Arnold P , Loveland C , Hull N , Saraiya M , Saydah S , Dumont W , Frakes LG , Johnson D , Peltier R , Van Houten C , Trujillo AA , Moore J , Rose DA , Honein MA , Carrington D , Harrist A , Hills SL . MMWR Morb Mortal Wkly Rep 2020 69 (26) 825-829 In the United States, approximately 180,000 patients receive mental health services each day at approximately 4,000 inpatient and residential psychiatric facilities (1). SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), can spread rapidly within congregate residential settings (2-4), including psychiatric facilities. On April 13, 2020, two patients were transferred to Wyoming's state psychiatric hospital from a private psychiatric hospital that had confirmed COVID-19 cases among its residents and staff members (5). Although both patients were asymptomatic at the time of transfer and one had a negative test result for SARS-CoV-2 at the originating facility, they were both isolated and received testing upon arrival at the state facility. On April 16, 2020, the test results indicated that both patients had SARS-CoV-2 infection. In response, the state hospital implemented expanded COVID-19 infection prevention and control (IPC) procedures (e.g., enhanced screening, testing, and management of new patient admissions) and adapted some standard IPC measures to facilitate implementation within the psychiatric patient population (e.g., use of modified face coverings). To assess the likely effectiveness of these procedures and determine SARS-CoV-2 infection prevalence among patients and health care personnel (HCP) (6) at the state hospital, a point prevalence survey was conducted. On May 1, 2020, 18 days after the patients' arrival, 46 (61%) of 76 patients and 171 (61%) of 282 HCP had nasopharyngeal swabs collected and tested for SARS-CoV-2 RNA by reverse transcription-polymerase chain reaction. All patients and HCP who received testing had negative test results, suggesting that the hospital's expanded IPC strategies might have been effective in preventing the introduction and spread of SARS-CoV-2 infection within the facility. In congregate residential settings, prompt identification of COVID-19 cases and application of strong IPC procedures are critical to ensuring the protection of other patients and staff members. Although standard guidance exists for other congregate facilities (7) and for HCP in general (8), modifications and nonstandard solutions might be needed to account for the specific needs of psychiatric facilities, their patients, and staff members. |
Progress toward polio eradication - worldwide, January 2018-March 2020
Chard AN , Datta SD , Tallis G , Burns CC , Wassilak SGF , Vertefeuille JF , Zaffran M . MMWR Morb Mortal Wkly Rep 2020 69 (25) 784-789 Since the Global Polio Eradication Initiative (GPEI) was established in 1988, two of the three wild poliovirus (WPV) serotypes (types 2 and 3) have been eradicated.* Transmission of WPV type 1 (WPV1) remains uninterrupted only in Afghanistan and Pakistan. This report summarizes progress toward global polio eradication during January 1, 2018-March 31, 2020 and updates previous reports (1,2). In 2019, Afghanistan and Pakistan reported the highest number of WPV1 cases (176) since 2014. During January 1-March 31, 2020 (as of June 19), 54 WPV1 cases were reported, an approximate fourfold increase from 12 cases during the corresponding period in 2019. Paralytic poliomyelitis can also be caused by circulating vaccine-derived poliovirus (cVDPV), which emerges when attenuated oral poliovirus vaccine (OPV) virus reverts to neurovirulence following prolonged circulation in underimmunized populations (3). Since the global withdrawal of type 2-containing OPV (OPV2) in April 2016, cVDPV type 2 (cVDPV2) outbreaks have increased in number and geographic extent (4). During January 2018-March 2020, 21 countries reported 547 cVDPV2 cases. Complicating increased poliovirus transmission during 2020, the coronavirus disease 2019 (COVID-19) pandemic and mitigation efforts have resulted in suspension of immunization activities and disruptions to poliovirus surveillance. When the COVID-19 emergency subsides, enhanced support will be needed to resume polio eradication field activities. |
Detection of rotavirus before and after monovalent rotavirus vaccine introduction and vaccine effectiveness among children in mainland Tanzania
Jani B , Hokororo A , McHomvu J , Cortese MM , Kamugisha C , Mujuni D , Kallovya D , Parashar UD , Mwenda JM , Lyimo D , Materu A , Omari KF , Waziri M , Laswai T , Juma H , Mlay J , Dogani J , Stephen E , Seugendo M , Nkumbi U , Lyakurwa A , Matojo A , Bendera E , Senyota J , Msingwa V , Fungo Y , Michael F , Mpamba A , Chambo A , Cholobi H , Lyamuya F , Chami I , McHome E , Mshana AM , Mushi E , Mariki U , Chard R , Tuju D , Ambokile N , Lukwale F , Kyessi F , Khamis A , Michael I , Macha D , Saguti A . Vaccine 2018 36 (47) 7149-7156 BACKGROUND: Monovalent rotavirus vaccine (RV1) was introduced in Tanzania in January 2013 under the Reach Every Child initiative, to be given at ages 6 and 10weeks. We used the sentinel hospital rotavirus surveillance system to examine the rotavirus detection rate before and after vaccine introduction and estimate vaccine effectiveness. METHODS: Before vaccine introduction, rotavirus surveillance was established at two mainland hospitals; children admitted for acute diarrhea were eligible for enrollment and stools were tested for rotavirus antigen. We compared the rotavirus positivity rate in the pre-vaccine period (Tanga Hospital, 2009 and 2011; Bugando Medical Centre, 2012) to that from post-introduction years, 2014-2015. In 2013, surveillance was established at 9 additional hospitals. We examined rotavirus positivity among infants at these sites for 2014-2015. We obtained vaccine records and calculated vaccine effectiveness at 3 sites using case-test-negative control design. RESULTS: At Tanga Hospital, the rotavirus positivity rate among infants was 41% (102/251) pre-vaccine and 14% (28/197) in post-vaccine years (rate ratio: 0.35 [95% CI 0.22-0.54]). At Bugando, the positivity rate was 58% (83/143) pre-vaccine, and 18% (49/277) post-introduction (rate ratio 0.30 [95% CI 0.210.44]). Results were similar among children <5years. At the new sites, the median site rotavirus positivity rate among infants was 26% in 2014 (range 19-44%) and 18% in 2015 (range 16-33%). The effectiveness of >/=1 RV1 dose against rotavirus hospitalization among children 5-23months was 53% (95% CI: -14, 81), and 66% (95% CI: 9-87) against hospitalization with intravenous rehydration. Following introduction, peak rotavirus activity occurred later in the year and appeared more concentrated in time. CONCLUSION: Rotavirus surveillance data from Tanzania indicate that the rotavirus positivity rate among children hospitalized with diarrhea that were enrolled was substantially reduced after vaccine introduction. Low positivity rates among infants were detected at hospitals across the country. Overall, the data support that rotavirus vaccine has been successfully introduced and is effective in Tanzanian children. |
The impact of school water, sanitation, and hygiene improvements on infectious disease using serum antibody detection
Chard AN , Trinies V , Moss DM , Chang HH , Doumbia S , Lammie PJ , Freeman MC . PLoS Negl Trop Dis 2018 12 (4) e0006418 BACKGROUND: Evidence from recent studies assessing the impact of school water, sanitation and hygiene (WASH) interventions on child health has been mixed. Self-reports of disease are subject to bias, and few WASH impact evaluations employ objective health measures to assess reductions in disease and exposure to pathogens. We utilized antibody responses from dried blood spots (DBS) to measure the impact of a school WASH intervention on infectious disease among pupils in Mali. METHODOLOGY/PRINCIPAL FINDINGS: We randomly selected 21 beneficiary primary schools and their 21 matched comparison schools participating in a matched-control trial of a comprehensive school-based WASH intervention in Mali. DBS were collected from 20 randomly selected pupils in each school (n = 807). We analyzed eluted IgG from the DBS using a Luminex multiplex bead assay to 28 antigens from 17 different pathogens. Factor analysis identified three distinct latent variables representing vector-transmitted disease (driven primarily by dengue), food/water-transmitted enteric disease (driven primarily by Escherichia coli and Vibrio cholerae), and person-to-person transmitted enteric disease (driven primarily by norovirus). Data were analyzed using a linear latent variable model. Antibody evidence of food/water-transmitted enteric disease (change in latent variable mean (beta) = -0.24; 95% CI: -0.53, -0.13) and person-to-person transmitted enteric disease (beta = -0.17; 95% CI: -0.42, -0.04) was lower among pupils attending beneficiary schools. There was no difference in antibody evidence of vector-transmitted disease (beta = 0.11; 95% CI: -0.05, 0.33). CONCLUSIONS/SIGNIFICANCE: Evidence of enteric disease was lower among pupils attending schools benefitting from school WASH improvements than students attending comparison schools. These findings support results from the parent study, which also found reduced incidence of self-reported diarrhea among pupils of beneficiary schools. DBS collection was feasible in this resource-poor field setting and provided objective evidence of disease at a low cost per antigen analyzed, making it an effective measurement tool for the WASH field. TRIAL REGISTRATION: The trial was registered at ClinicalTrials.gov (NCT01787058). |
Detection of immunoglobulin G antibodies to Taenia solium cysticercosis antigen glutathione-S-transferase-rT24H in Malian children using multiplex bead assay
Moss DM , Handali S , Chard AN , Trinies V , Bullard S , Wiegand RE , Doumbia S , Freeman MC , Lammie PJ . Am J Trop Med Hyg 2018 98 (5) 1408-1412 Blood samples from 805 students attending 42 elementary schools in Mopti, Sikasso, and Koulikoro regions, and Bamako district in Mali participated in a school water, sanitation, and hygiene intervention. Immunoglobulin (Ig) G responses to several antigens/pathogens were assessed by a multiplex bead assay (MBA), and the recombinant Taenia solium T24H antigen was included. Of all students tested, 8.0% were positive to rT24H, but in some schools 25-30%. A cluster of 12 widespread school locations showed not only a relative risk of 3.23 for T. solium exposure and significantly higher IgG responses (P < 0.001) but also significantly lower elevation (P = 0.04) (m, above sea level) compared with schools outside the cluster. All schools at elevations < 425 m showed significantly higher IgG responses (P = 0.017) than schools at elevations >/= 425 m. The MBA is an excellent serological platform that provides cost-effective opportunities to expand testing in serosurveys. |
Evaluation of immunoglobulin g responses to Plasmodium falciparum and Plasmodium vivax in Malian school children using multiplex bead assay
Rogier E , Moss DM , Chard AN , Trinies V , Doumbia S , Freeman MC , Lammie PJ . Am J Trop Med Hyg 2016 96 (2) 312-318 Malaria serology through assaying for IgG against Plasmodium spp. antigens provides evidence into the infection history for an individual. The multiplex bead assay (MBA) allows for detection of IgG against multiple Plasmodium spp., and can be especially useful in many regions where Plasmodium falciparum is of primary clinical focus, but other species are co-endemic. Dried blood spots were collected from 805 Malian children attending 42 elementary schools in the regions of Mopti, Sikasso, Koulikoro, and Bamako capital district, and IgG assayed by MBA. As southern Mali is known to be holoendemic for P. falciparum, merozoite surface protein 1 19-kDa subunit (MSP-142) and apical membrane antigen 1 (AMA-1) antigens were included for serology against this parasite. Responses to these antigens both provided high estimates for lifetime exposure, with 730 (90%) children with IgG antibodies for MSP-142, 737 (91%) for AMA-1, and 773 (96%) positive for either or both. Also included was the antigen Plasmodium vivax MSP-119, against which 140 (17.4%) children were found to have antibodies. Increases in antibody titers with older age were clearly seen with the P. falciparum antigens, but not with the P. vivax antigen, likely indicating more of a sporadic, rather than sustained transmission for this species. The MBA provides effective opportunities to evaluate malaria transmission through serological analysis for multiple Plasmodium species. |
Serological responses to filarial antigens in Malian children attending elementary schools
Moss DM , Chard AN , Trinies V , Doumbia S , Freeman MC , Lammie PJ . Am J Trop Med Hyg 2016 96 (1) 229-232 Dried blood spots (DBS) were collected from 805 children attending 42 elementary schools in the regions of Mopti, Sikasso, Koulikoro, and the regional capital of Bamako in Mali as part of an evaluation of a school health intervention. Eluted immunoglobulin (Ig) G from the DBS was assessed by a multiplex bead assay (MBA) for two filariasis antigens, Wuchereria bancrofti, Wb123, and Brugia malayi, Bm14, to determine the effectiveness of mass drug administration (MDA) programs to eliminate lymphatic filariasis (LF). The prevalence of positive IgG responses in the children to each antigen was less than 1%, indicating effectiveness of the MDA against LF. The MBA is an excellent serological platform that provides cost-effective opportunities to evaluate public health activities beyond the survey targets. |
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