Last data update: Apr 29, 2024. (Total: 46658 publications since 2009)
Records 1-30 (of 43 Records) |
Query Trace: Guagliardo SAJ[original query] |
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Prevalence of undiagnosed monkeypox virus infections during global mpox outbreak, United States, June-September 2022
Minhaj FS , Singh V , Cohen SE , Townsend M , Scott H , Szumowski J , Hare CB , Upadhyay P , Reddy J , Alexander B , Baird N , Navarra T , Priyamvada L , Wynn N , Carson WC , Odafe S , Guagliardo SAJ , Sims E , Rao AK , Satheshkumar PS , Weidle PJ , Hutson CL . Emerg Infect Dis 2023 29 (11) 2307-2314 Since May 2022, mpox has been identified in 108 countries without endemic disease; most cases have been in gay, bisexual, or other men who have sex with men. To determine number of missed cases, we conducted 2 studies during June-September 2022: a prospective serologic survey detecting orthopoxvirus antibodies among men who have sex with men in San Francisco, California, and a retrospective monkeypox virus PCR testing of swab specimens submitted for other infectious disease testing among all patients across the United States. The serosurvey of 225 participants (median age 34 years) detected 18 (8.0%) who were orthopoxvirus IgG positive and 3 (1.3%) who were also orthopoxvirus IgM positive. The retrospective PCR study of 1,196 patients (median age 30 years; 54.8% male) detected 67 (5.6%) specimens positive for monkeypox virus. There are likely few undiagnosed cases of mpox in regions where sexual healthcare is accessible and patient and clinician awareness about mpox is increased. |
How the orthodox features of orthopoxviruses led to an unorthodox Mpox outbreak: What we've learned, and what we still need to understand
Brooks JT , Reynolds MG , Torrone E , McCollum A , Spicknall IH , Gigante CM , Li Y , Satheshkumar PS , Quilter LAS , Rao AK , O'Shea J , Guagliardo SAJ , Townsend M , Hutson CL . J Infect Dis 2023 Orthopoxviruses are complex, large-genome DNA viruses that have repeatedly confounded expectations in terms of the clinical illness they cause and their patterns of spread. Monkeypox virus (MPXV) was originally characterized during outbreaks among captive primates in the late 1950's. Human disease (mpox) has been observed since the 1970's and inter-human spread has largely been associated with non-sexual, close physical contact in endemic areas of west and central Africa. In May 2022, a focus of Clade IIb MPXV transmission was detected, spreading largely by sexual contact through international networks of gay, bisexual, and other men who have sex with men. Despite decades of preparedness for the potential biothreat risk posed by smallpox, the outbreak grew in both size and geographic scope, testing the strength of smallpox preparedness tools and public health science alike. In this article we consider what was known about mpox prior to the 2022 outbreak, what we have learned about mpox and Clade IIb virus during the outbreak, and what outbreak response actions and continued research are needed to ensure the global public health community is equipped to detect and halt the further spread of this disease threat. We focus on how epidemiologic characterization and investigation together with laboratory studies have advanced our understanding of the transmission and pathogenesis of mpox, and describe what work remains to be done to optimize diagnostics, therapeutics, and vaccines. Persistent health inequities challenge our capacity to fully eliminate circulation of the 2022 outbreak strain of MPXV currently in the United States. |
COVID-19 epidemiology during Delta variant dominance period in 45 high-income countries, 2020-2021
Atherstone CJ , Guagliardo SAJ , Hawksworth A , O'Laughlin K , Wong K , Sloan ML , Henao O , Rao CY , McElroy PD , Bennett SD . Emerg Infect Dis 2023 29 (9) 1757-1764 The SARS-CoV-2 Delta variant, first identified in October 2020, quickly became the dominant variant worldwide. We used publicly available data to explore the relationship between illness and death (peak case rates, death rates, case-fatality rates) and selected predictors (percentage vaccinated, percentage of the population >65 years, population density, testing volume, index of mitigation policies) in 45 high-income countries during the Delta wave using rank-order correlation and ordinal regression. During the Delta-dominant period, most countries reported higher peak case rates (57%) and lower peak case-fatality rates (98%). Higher vaccination coverage was protective against peak case rates (odds ratio 0.95, 95% CI 0.91-0.99) and against peak death rates (odds ratio 0.96, 95% CI 0.91-0.99). Vaccination coverage was vital to preventing infection and death from COVID-19 during the Delta wave. As new variants emerge, public health authorities should encourage the uptake of COVID-19 vaccination and boosters. |
Possible exposures among mpox patients without reported male-to-male sexual contact - six U.S. Jurisdictions, November 1-December 14, 2022
Sharpe JD , Charniga K , Byrd KM , Stefanos R , Lewis L , Watson J , Feldpausch A , Pavlick J , Hand J , Sokol T , Ortega E , Pathela P , Hennessy RR , Dulcey M , McHugh L , Pietrowski M , Perella D , Shah S , Maroufi A , Taylor M , Cope A , Belay ED , Ellington S , McCollum AM , Zilversmit Pao L , Guagliardo SAJ , Dawson P . MMWR Morb Mortal Wkly Rep 2023 72 (35) 944-948 The extent to which the 2022 mpox outbreak has affected persons without a recent history of male-to-male sexual contact (MMSC) is not well understood. During November 1-December 14, 2022, CDC partnered with six jurisdictional health departments to characterize possible exposures among mpox patients aged ≥18 years who did not report MMSC during the 3 weeks preceding symptom onset. Among 52 patients included in the analysis, 14 (27%) had a known exposure to a person with mpox, including sexual activity and other close intimate contact (eight) and household contact (six). Among 38 (73%) patients with no known exposure to a person with mpox, self-reported activities before illness onset included sexual activity and other close intimate contact (17; 45%), close face-to-face contact (14; 37%), attending large social gatherings (11; 29%), and being in occupational settings involving close skin-to-skin contact (10; 26%). These findings suggest that sexual activity remains an important route of mpox exposure among patients who do not report MMSC. |
Linked surveillance and genetic data uncovers programmatically relevant geographic scale of Guinea worm transmission in Chad (preprint)
Ribado JV , Li N , Thiele E , Lyons H , Cotton JA , Weiss A , Tchindebet Ouakou P , Moundai T , Zirimwabagabo H , Guagliardo SAJ , Chabot-Couture G , Proctor JL . medRxiv 2020 2020.10.05.20207324 Background Guinea worm (Dracunculus medinensis) was detected in Chad in 2010 after a supposed ten year absence, posing a challenge to the global eradication effort. Initiation of a village-based surveillance system in 2012 revealed a substantial number of dogs infected with Guinea worm, raising questions about paratenic hosts and cross-species transmission.Methodology/Principal Findings We coupled genomic and surveillance data from 2012-2018 cases to investigate the modes of transmission between hosts and the geographic connectivity for genetically similar worm populations. Eighty-six variants across three loci on the mitochondrial genome identified 41 genetically distinct worm genotypes. Spatiotemporal modeling reveals genetically identical worms are within a median range of 18.6 kilometers of each other, but largely within approximately 50 kilometers. Genetically identical worms vary in their degree of spatial clustering, suggesting there may be different factors that favor or constrain transmission. Each worm is surrounded by five to ten genetically distinct worms within a 50 kilometer radius. In an independent population, we show that more variants revealed in whole mitochondrial genome data improved the discrimination between worm pairs.Conclusions/Significance In the largest study linking genetic and surveillance data to date of Guinea worm cases in Chad, we show genetic similarity and modeling can contribute to understanding local transmission. The overlap of genetically distinct worms in quantitatively identified transmission ranges highlights the necessity for genomic tools to link cases. The improved discrimination between worm pairs from variants identified across the complete mitochondrial genome indicates expanding genomic markers could link cases at a finer scale. These results suggest that scaling up genomic surveillance for Guinea worm may provide additional value for programmatic decision-making critical for monitoring cases and intervention efficacy to achieve elimination.Competing Interest StatementThe authors have declared no competing interest.Funding StatementJR, GCC, HL, and JLP would like to thank Bill and Melinda Gates for their active support of the Institute for Disease Modeling and their sponsorship through the Global Good Fund. JAC was supported by funding from The Carter Center and Wellcome, via their core support for the Wellcome Sanger Institute (grant WT206194).Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:N/A; Worm collection and associated metadata are routine in country surveillance efforts.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesGenomic data and source code will be made available upon publication. Requests for epidemiological data that includes case coordinates must be submitted to and approved by the Chad Guinea Worm Eradication Program. |
Early detection of SARS-CoV-2 variants using traveler-based genomic surveillance at four US airports, September 2021- January 2022 (preprint)
Wegrzyn RD , Appiah GD , Morfino R , Milford SR , Walker AT , Ernst ET , Darrow WW , Li SL , Robison K , MacCannell D , Dai D , Girinathan BP , Hicks AL , Cosca B , Woronoff G , Plocik AM , Simen BB , Moriarty L , Guagliardo SAJ , Cetron MS , Friedman CR . medRxiv 2022 22 Background Despite layered mitigation measures, international travel during the COVID-19 pandemic continues to facilitate global spread of SARS-CoV-2, including novel variants of concern (VOCs). On November 26, 2021, B.1.1.529 (Omicron) was designated as a VOC by the World Health Organization [1]. On December 6, 2021, as part of measures to reduce the introduction and spread of Omicron, the requirement for a negative SARS-CoV-2 test taken before air travel to the United States was shortened from three days to one day pre-departure [1]. Although SARS-CoV-2 genomic sequencing has increased significantly during the pandemic [2], there is still a gap in early detection of emerging variants among arriving travelers. In September 2021, the Centers for Disease Control and Prevention (CDC), in collaboration with private partners, implemented a voluntary SARS-CoV-2 genomic surveillance pilot program. Initially we enrolled arriving air travelers from India. On November 28, we expanded the program to include travelers arriving from countries with high travel volumes, including those where Omicron was first detected. Methods Design, Setting, and Participants During September 29-November 27, 2021, the surveillance program included travelers arriving on seven direct flights from India at three international airports: John F. Kennedy, New York (September 29), Newark Liberty, New Jersey (October 4), and San Francisco, California (October 12). During November 28-January 23, Hartsfield-Jackson Atlanta International Airport, Georgia was added, and participation was offered to travelers from South Africa, Nigeria, the United Kingdom, France, Germany, and Brazil, arriving on approximately 50 flights per day. Participants were 18 years or older, provided informed consent, and completed demographic, clinical, and travel history questions. 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. |
Changes in trachoma indicators in Kiribati with two rounds of azithromycin mass drug administration, measured in serial population-based surveys
Goodhew EB , Taoaba R , Harding-Esch EM , Gwyn SE , Bakhtiari A , Butcher R , Cama A , Guagliardo SAJ , Jimenez C , Mpyet CD , Tun K , Wickens K , Solomon AW , Martin DL , Tekeraoi R . PLoS Negl Trop Dis 2023 17 (7) e0011441 Baseline mapping in the two major population centers of Kiribati showed that trachoma was a public health problem in need of programmatic interventions. After conducting two annual rounds of antibiotic mass drug administration (MDA), Kiribati undertook trachoma impact surveys in 2019, using standardized two-stage cluster surveys in the evaluation units of Kiritimati Island and Tarawa. In Kiritimati, 516 households were visited and in Tarawa, 772 households were visited. Nearly all households had a drinking water source and access to an improved latrine. The prevalence of trachomatous trichiasis remained above the elimination threshold (0.2% in ≥15-year-olds) and was virtually unchanged from baseline. The prevalence of trachomatous inflammation-follicular (TF) in 1-9-year-olds decreased by approximately 40% from baseline in both evaluation units but remained above the 5% TF prevalence threshold for stopping MDA. TF prevalence at impact survey was 11.5% in Kiritimati and 17.9% in Tarawa. Infection prevalence in 1-9-year-olds by PCR was 0.96% in Kiritimati and 3.3% in Tarawa. Using a multiplex bead assay to measure antibodies to the C. trachomatis antigen Pgp3, seroprevalence in 1-9-year-olds was 30.2% in Kiritimati and 31.4% in Tarawa. The seroconversion rate, in seroconversion events/100 children/year, was 9.0 in Kiritimati and 9.2 in Tarawa. Seroprevalence and seroconversion rates were both assessed by four different assays, with strong agreement between tests. These results show that, despite decreases in indicators associated with infection at impact survey, trachoma remains a public health problem in Kiribati, and provide additional information about changes in serological indicators after MDA. |
Treponemal antibody seroprevalence using a multiplex bead assay from samples collected during the 2018 Nigeria HIV/AIDS indicator and impact survey: Searching for yaws in Nigeria
Guagliardo SAJ , Parameswaran N , Agala N , Abubakar A , Cooley G , Ye T , Kamb M , Mba N , William N , Greby S , Iriemenam N , Alagi M , Okoye M , Martin D . Am J Trop Med Hyg 2023 108 (5) 977-980 Yaws is a chronic, relapsing disease of skin, bone, and cartilage caused by Treponema pallidum subsp. pertenue. Yaws was last reported in Nigeria in 1996, although neighboring countries have recently reported cases. We investigated serological evidence for yaws among children aged 0-14 years in Nigeria by measuring antibodies to the treponemal antigens rp17 and TmpA in blood specimens from a 2018 nationally representative HIV survey using a multiplex bead assay. The presence of antibodies to both antigens ("double positive") likely reflects current or recent treponemal infection. Overall, 1.9% (610/31,549) of children had anti-TmpA antibodies, 1.5% (476/31,549) had anti-rp17 antibodies, and 0.1% (39/31,549) were double positive. Among households, 0.5% (84/18,021) had a double-positive child, with a clustering of double-positive children. Although numbers are low, identification of antibodies to both TmpA and rp17 may warrant investigation, including more granular epidemiologic and clinical data, to assess the potential for continuing yaws transmission in Nigerian children. |
Epidemiologic and clinical features of Mpox-associated deaths - United States, May 10, 2022-March 7, 2023
Riser AP , Hanley A , Cima M , Lewis L , Saadeh K , Alarcón J , Finn L , Kim M , Adams J , Holt D , Feldpausch A , Pavlick J , English A , Smith M , Rehman T , Lubelchek R , Black S , Collins M , Mounsey L , Blythe D , Avalos MH , Lee EH , Samson O , Wong M , Stokich BD , Salehi E , Denny L , Waller K , Talley P , Schuman J , Fischer M , White S , Davis K , Caeser Cuyler A , Sabzwari R , Anderson RN , Byrd K , Gold JAW , Kindilien S , Lee JT , O'Connor S , O'Shea J , Salmon-Trejo LAT , Velazquez-Kronen R , Zelaya C , Bower W , Ellington S , Gundlapalli AV , McCollum AM , Zilversmit Pao L , Rao AK , Wong KK , Guagliardo SAJ . MMWR Morb Mortal Wkly Rep 2023 72 (15) 404-410 As of March 7, 2023, a total of 30,235 confirmed and probable monkeypox (mpox) cases were reported in the United States,(†) predominantly among cisgender men(§) who reported recent sexual contact with another man (1). Although most mpox cases during the current outbreak have been self-limited, cases of severe illness and death have been reported (2-4). During May 10, 2022-March 7, 2023, 38 deaths among persons with probable or confirmed mpox(¶) (1.3 per 1,000 mpox cases) were reported to CDC and classified as mpox-associated (i.e., mpox was listed as a contributing or causal factor). Among the 38 mpox-associated deaths, 94.7% occurred in cisgender men (median age = 34 years); 86.8% occurred in non-Hispanic Black or African American (Black) persons. The median interval from symptom onset to death was 68 days (IQR = 50-86 days). Among 33 decedents with available information, 93.9% were immunocompromised because of HIV. Public health actions to prevent mpox deaths include integrated testing, diagnosis, and early treatment for mpox and HIV, and ensuring equitable access to both mpox and HIV prevention and treatment, such as antiretroviral therapy (ART) (5). |
Mpox respiratory transmission: the state of the evidence.
Beeson A , Styczynski A , Hutson CL , Whitehill F , Angelo KM , Minhaj FS , Morgan C , Ciampaglio K , Reynolds MG , McCollum AM , Guagliardo SAJ . Lancet Microbe 2023 4 (4) e277-e283 The relative contribution of the respiratory route to transmission of mpox (formerly known as monkeypox) is unclear. We review the evidence for respiratory transmission of monkeypox virus (MPXV), examining key works from animal models, human outbreaks and case reports, and environmental studies. Laboratory experiments have initiated MPXV infection in animals via respiratory routes. Some animal-to-animal respiratory transmission has been shown in controlled studies, and environmental sampling studies have detected airborne MPXV. Reports from real-life outbreaks demonstrate that transmission is associated with close contact, and although it is difficult to infer the route of MPXV acquisition in individual case reports, so far respiratory transmission has not been specifically implicated. Based on the available evidence, the likelihood of human-to-human MPXV respiratory transmission appears to be low; however, studies should continue to assess this possibility. |
Effect of predeparture testing on postarrival SARS-CoV-2-positive test results among international travelers - CDC traveler-based genomic surveillance program, four U.S. Airports, March-September 2022
Bart SM , Smith TC , Guagliardo SAJ , Walker AT , Rome BH , Li SL , Aichele TWS , Stein R , Ernst ET , Morfino RC , Cetron MS , Friedman CR . MMWR Morb Mortal Wkly Rep 2023 72 (8) 206-209 Beginning December 6, 2021, all international air passengers boarding flights to the United States were required to show either a negative result from a SARS-CoV-2 viral test taken ≤1 day before departure or proof of recovery from COVID-19 within the preceding 90 days (1). As of June 12, 2022, predeparture testing was no longer mandatory but remained recommended by CDC (2,3). Various modeling studies have estimated that predeparture testing the day before or the day of air travel reduces transmission or importation of SARS-CoV-2 by 31%-76% (4-7). Postarrival SARS-CoV-2 pooled testing data from CDC's Traveler-based Genomic Surveillance program were used to compare SARS-CoV-2 test results among volunteer travelers arriving at four U.S. airports during two 12-week periods: March 20-June 11, 2022, when predeparture testing was required, and June 12-September 3, 2022, when predeparture testing was not required. In a multivariable logistic regression model, pooled nasal swab specimens collected during March 20-June 11 were 52% less likely to be positive for SARS-CoV-2 than were those collected during June 12-September 3, after adjusting for COVID-19 incidence in the flight's country of origin, sample pool size, and collection airport (adjusted odds ratio [aOR] = 0.48, 95% CI = 0.39-0.58) (p<0.001). These findings support predeparture testing as a tool for reducing travel-associated SARS-CoV-2 transmission and provide important real-world evidence that can guide decisions for future outbreaks and pandemics. |
Determining Gaps in Publicly Shared SARS-CoV-2 Genomic Surveillance Data by Analysis of Global Submissions.
Ohlsen EC , Hawksworth AW , Wong K , Guagliardo SAJ , Fuller JA , Sloan ML , O'Laughlin K . Emerg Infect Dis 2022 28 (13) S85-s92 Viral genomic surveillance has been a critical source of information during the COVID-19 pandemic, but publicly available data can be sparse, concentrated in wealthy countries, and often made public weeks or months after collection. We used publicly available viral genomic surveillance data submitted to GISAID and GenBank to examine sequencing coverage and lag time to submission during 2020-2021. We compared publicly submitted sequences by country with reported infection rates and population and also examined data based on country-level World Bank income status and World Health Organization region. We found that as global capacity for viral genomic surveillance increased, international disparities in sequencing capacity and timeliness persisted along economic lines. Our analysis suggests that increasing viral genomic surveillance coverage worldwide and decreasing turnaround times could improve timely availability of sequencing data to inform public health action. |
COVID-19 on the Nile: a cross-sectional investigation of COVID-19 among Nile River cruise travellers returning to the United States, February-march 2020.
Guagliardo SAJ , Quilter LAS , Uehara A , White SB , Talarico S , Tong S , Paden CR , Zhang J , Li Y , Pray I , Novak RT , Fukunaga R , Rodriguez A , Medley AM , Wagner R , Weinberg M , Brown CM , Friedman CR . J Travel Med 2022 BACKGROUND: Early in the pandemic, cruise travel exacerbated the global spread of SARS-CoV-2. We report epidemiologic and molecular findings from an investigation of a cluster of travelers with confirmed COVID-19 returning to the U.S. from Nile River cruises in Egypt. METHODS: State health departments reported data on real-time reverse transcription-polymerase chain reaction-confirmed COVID-19 cases with a history of Nile River cruise travel during February-March 2020 to the Centers for Disease Control and Prevention (CDC). Demographic and epidemiologic data were collected through routine surveillance channels. Sequences were obtained from either state health departments or from the Global Initiative on Sharing Avian Flu Data (GISAID). We conducted descriptive analyses of epidemiologic data and explored phylogenetic relationships between sequences. RESULTS: We identified 149 Nile River cruise travelers with confirmed COVID-19 who returned to 67 different U.S. counties in 27 states: among those with complete data, 4.7% (6/128) died and 28.1% (38/135) were hospitalized. These individuals traveled on 20 different Nile River cruise voyages (12 unique vessels). Fifteen community transmission events were identified in four states, with 73.3% (11/15) of these occurring in Wisconsin (as the result of a more detailed contact investigation in that state). Phylogenetic analyses supported the hypothesis that travelers were most likely infected in Egypt, with most sequences in Nextstrain clade 20A 93% (87/94). We observed genetic clustering by Nile River cruise voyage and vessel. CONCLUSIONS: Nile River cruise travelers with COVID-19 introduced SARS-CoV-2 over a very large geographic range, facilitating transmission across the United States early in the pandemic. Travelers who participate in cruises, even on small river vessels as investigated in this study, are at increased risk of SARS-CoV-2 exposure. Therefore, history of river cruise travel should be considered in contact tracing and outbreak investigations. |
Epidemiological and clinical characteristics of patients with monkeypox in the GeoSentinel Network: a cross-sectional study
Angelo KM , Smith T , Camprubí-Ferrer D , Balerdi-Sarasola L , Díaz Menéndez M , Servera-Negre G , Barkati S , Duvignaud A , Huber KLB , Chakravarti A , Bottieau E , Greenaway C , Grobusch MP , Mendes Pedro D , Asgeirsson H , Popescu CP , Martin C , Licitra C , de Frey A , Schwartz E , Beadsworth M , Lloveras S , Larsen CS , Guagliardo SAJ , Whitehill F , Huits R , Hamer DH , Kozarsky P , Libman M . Lancet Infect Dis 2022 23 (2) 196-206 BACKGROUND: The early epidemiology of the 2022 monkeypox epidemic in non-endemic countries differs substantially from the epidemiology previously reported from endemic countries. We aimed to describe the epidemiological and clinical characteristics among individuals with confirmed cases of monkeypox infection. METHODS: We descriptively analysed data for patients with confirmed monkeypox who were included in the GeoSentinel global clinical-care-based surveillance system between May 1 and July 1 2022, across 71 clinical sites in 29 countries. Data collected included demographics, travel history including mass gathering attendance, smallpox vaccination history, social history, sexual history, monkeypox exposure history, medical history, clinical presentation, physical examination, testing results, treatment, and outcomes. We did descriptive analyses of epidemiology and subanalyses of patients with and without HIV, patients with CD4 counts of less than 500 cells per mm(3) or 500 cells per mm(3) and higher, patients with one sexual partner or ten or more sexual partners, and patients with or without a previous smallpox vaccination. FINDINGS: 226 cases were reported at 18 sites in 15 countries. Of 211 men for whom data were available, 208 (99%) were gay, bisexual, or men who have sex with men (MSM) with a median age of 37 years (range 18-68; IQR 32-43). Of 209 patients for whom HIV status was known, 92 (44%) men had HIV infection with a median CD4 count of 713 cells per mm(3) (range 36-1659; IQR 500-885). Of 219 patients for whom data were available, 216 (99%) reported sexual or close intimate contact in the 21 days before symptom onset; MSM reported a median of three partners (IQR 1-8). Of 195 patients for whom data were available, 78 (40%) reported close contact with someone who had confirmed monkeypox. Overall, 30 (13%) of 226 patients were admitted to hospital; 16 (53%) of whom had severe illness, defined as hospital admission for clinical care rather than infection control. No deaths were reported. Compared with patients without HIV, patients with HIV were more likely to have diarrhoea (p=0·002), perianal rash or lesions (p=0·03), and a higher rash burden (median rash burden score 9 [IQR 6-21] for patients with HIV vs median rash burden score 6 [IQR 3-14] for patients without HIV; p<0·0001), but no differences were identified in the proportion of men who had severe illness by HIV status. INTERPRETATION: Clinical manifestations of monkeypox infection differed by HIV status. Recommendations should be expanded to include pre-exposure monkeypox vaccination of groups at high risk of infection who plan to engage in sexual or close intimate contact. FUNDING: US Centers for Disease Control and Prevention, International Society of Travel Medicine. |
Early detection of SARS-CoV-2 variants using traveler-based genomic surveillance at four US airports, September 2021- January 2022.
Wegrzyn RD , Appiah GD , Morfino R , Milford SR , Walker AT , Ernst ET , Darrow WW , Li SL , Robison K , MacCannell D , Dai D , Girinathan BP , Hicks AL , Cosca B , Woronoff G , Plocik AM , Simen BB , Moriarty L , Guagliardo SAJ , Cetron MS , Friedman CR . Clin Infect Dis 2023 76 (3) e540-e543 We enrolled arriving international air travelers in a severe acute respiratory syndrome coronavirus 2 genomic surveillance program. We used molecular testing of pooled nasal swabs and sequenced positive samples for sublineage. Traveler-based surveillance provided early-warning variant detection, reporting the first US Omicron BA.2 and BA.3 in North America. |
SARS-CoV-2 Breakthrough Infections among US Embassy Staff Members, Uganda, May-June 2021.
Harris JR , Owusu D , O'Laughlin K , Cohen AL , Ben Hamida A , Patel JC , Freeman MM , Nsibambi T , Nieves R , Marston BJ , Wasike S , Galbraith JS , Boore AL , Nelson LJ , Guagliardo SAJ , Klena JD , Patel K , Ma M . Emerg Infect Dis 2022 28 (6) 1279-1280 The SARS-CoV-2 Delta variant emerged shortly after COVID-19 vaccines became available in 2021. We describe SARS-CoV-2 breakthrough infections in a highly vaccinated, well-monitored US Embassy community in Kampala, Uganda. Defining breakthrough infection rates in highly vaccinated populations can help determine public health messaging, guidance, and policy globally. |
Epidemiological and molecular investigations of a point-source outbreak of Dracunculus medinensis infecting humans and dogs in Chad: a cross-sectional study.
Guagliardo SAJ , Thiele E , Unterwegner K , Narcisse Nanguita N , Dossou L , Tchindebet Ouakou P , Zirimwabagabo H , Ruiz-Tiben E , Hopkins DR , Roy SL , Cama V , Bishop H , Sapp S , Yerian S , Weiss AJ . Lancet Microbe 2022 3 (2) e105-e112 BACKGROUND: Dracunculiasis (also known as Guinea worm disease), caused by the Dracunculus medinensis nematode, is progressing towards eradication, with a reduction in cases from 3·5 million cases in the mid-1980s to only 54 human cases at the end of 2019. Most cases now occur in Chad. On April 19, 2019, a 19-year-old woman presented with D medinensis in an area within the Salamat region of Chad, where the disease had not been previously reported. We aimed to investigate the connection between this case and others detected locally and elsewhere in Chad using a combination of epidemiological and genetic approaches. METHODS: In this cross-sectional field study, we conducted household case searches and informal group interviews in the Bogam, Liwi, and Tarh villages in Chad. All community members including children were eligible for participation in the outbreak investigation. Adult female D medinensis associated with this outbreak were collected for genetic analysis (18 from humans and two from dogs). Four mitochondrial genes and 22 nuclear microsatellite markers were used to assess relatedness of worms associated with the outbreak in comparison with other worms from elsewhere in Chad. FINDINGS: Between April 12 and Sept 6, 2019, we identified 22 human cases and two canine cases of dracunculiasis associated with 15 households. Six (40%) of the 15 affected households had multiple human or canine cases within the household. Most cases of dracunculiasis in people were from three villages in Salamat (21 [95%] of 22 cases), but one case was detected nearly 400 km away in Sarh city (outside the Salamat region). All people with dracunculiasis reported a history of consuming fish and unfiltered water. Worms associated with this outbreak were genetically similar and shared the same maternal lineage. INTERPRETATION: Molecular epidemiological results suggest a point-source outbreak that originated from a single female D medinensis, rather than newly identified sustained local transmission. The failure of the surveillance system to detect the suspected canine infection in 2018 highlights the challenge of canine D medinensis detection, particularly in areas under passive surveillance. Human movement can also contribute to dracunculiasis spread over long distances. FUNDING: The Carter Center. |
Post-validation survey in two districts of Morocco after the elimination of trachoma as a public health problem
Hammou J , Guagliardo SAJ , Obtel M , Razine R , Haroun AE , Youbi M , Bellefquih AM , White M , Gwyn S , Martin DL . Am J Trop Med Hyg 2022 106 (5) 1370-8 Trachoma is the leading infectious cause of blindness. In 2016, Morocco was validated by WHO as having eliminated trachoma as a public health problem. We evaluated two previously endemic districts in Morocco for trachomatous inflammation-follicular (TF), trachomatous trichiasis (TT), and antibodies against Chlamydia trachomatis, the causative agent of trachoma. Community-based cross-sectional surveys in the districts of Boumalene Dades and Agdez included 4,445 participants for whom both questionnaire and serology data were available; 58% were aged 1-9 years. Participants had eyes examined for TF and blood collected for analysis of antibodies to the C. trachomatis antigen Pgp3 by both a multiplex bead assay (MBA) and lateral flow assay (LFA). Seroconversion rates (SCR) per 100 people per year were used to estimate changes in the force of infection using Bayesian serocatalytic models. In Agdez, TF prevalence in 1-9-year-olds was 0.3%, seroprevalence ranged from 9.4% to 11.4%, and SCR estimates ranged from 2.4 to 3.0. In Boumalene Dades, TF prevalence in 1-9-year-olds was 0.07%, and modeling data from the different assays indicated a decrease in transmission between 20 and 24 years ago. The TF data support an absence of active trachoma in the two districts examined. However, seroprevalence and SCR in younger people were higher in Agdez than Boumalene Dades, showing that there can be differences in serology metrics in areas with similar TF prevalence. Data will be included in multicountry analyses to better understand potential thresholds for serological surveillance in trachoma. |
Investigating flubendazole as an anthelmintic treatment for Guinea worm (Dracunculus medinensis): Clinical trials in laboratory-reared ferrets and domestic dogs in Chad
Cleveland CA , Garrett KB , Box EK , Thompson AT , Haynes EK , Elder DL , Richards RL , Majewska AA , Guagliardo SAJ , Wiegand RE , Bryan Ii JA , Torres-Velez F , Unterwegner K , Romero M , Zirimwabagabo H , Sidouin M , Oaukou PT , Ada MM , Ngandolo BNR , Mackenzie CD , Geary TG , Weiss AJ , Yabsley MJ . Am J Trop Med Hyg 2022 106 (5) 1456-65 Dracunculus medinensis (Guinea worm [GW]), a zoonotic nematode targeted for eradication, has been managed using interventions aimed at humans; however, increases in domestic dog GW infections highlight the need for novel approaches. We conducted two clinical trials evaluating the efficacy of subcutaneously injected flubendazole (FBZ) as a treatment of GW infection. The first trial was conducted administering FBZ to experimentally infected ferrets; the second trial involved administering FBZ or a placebo to domestic dogs in the Republic of Tchad (Chad). We found contrasting results between the two trials. When adult gravid female GW were recovered from ferrets treated with FBZ, larvae presented in poor condition, with low to no motility, and an inability to infect copepods. Histopathology results indicated a disruption to morulae development within uteri of worms from treated animals. Results from the trial in Chadian dogs failed to indicate significant treatment of or prevention against GW infection. However, the difference in treatment intervals (1 month for ferrets and 6 months for dogs) or the timing of treatment (ferrets were treated later in the GW life-cycle than dogs) could explain different responses to the subcutaneous FBZ injections. Both trials provided valuable data guiding the use of FBZ in future trials (such as decreasing treatment intervals or increasing the dose of FBZ in dogs to increase exposure), and highlighted important lessons learned during the implementation of a field-based, double-blinded randomized control trial in Chadian dogs. |
Household transmission of SARS-CoV-2 Alpha variant - United States, 2021.
Donnelly MAP , Chuey MR , Soto R , Schwartz NG , Chu VT , Konkle SL , Sleweon S , Ruffin J , Haberling DL , Guagliardo SAJ , Stoddard RA , Anderson RD , Morgan CN , Rossetti R , McCormick DW , Magleby R , Sheldon SW , Dietrich EA , Uehara A , Retchless AC , Tong S , Folster JM , Drobeniuc J , Petway ME , Austin B , Stous S , McDonald E , Jain S , Hudziec MM , Stringer G , Albanese BA , Totten SE , Staples JE , Killerby ME , Hughes L , Matanock A , Beatty M , Tate JE , Kirking HL , Hsu CH . Clin Infect Dis 2022 75 (1) e122-e132 BACKGROUND: In Spring 2021, SARS-CoV-2 B.1.1.7 (Alpha) became the predominant variant in the U.S. Research suggests that Alpha has increased transmissibility compared to non-Alpha lineages. We estimated household secondary infection risk (SIR), assessed characteristics associated with transmission, and compared symptoms of persons with Alpha and non-Alpha infections. METHODS: We followed households with SARS-CoV-2 infection for two weeks in San Diego County and metropolitan Denver, January to April 2021. We collected epidemiologic information and biospecimens for serology, RT-PCR, and whole genome sequencing. We stratified SIR and symptoms by lineage, and identified characteristics associated with transmission using Generalized Estimating Equations. RESULTS: We investigated 127 households with 322 household contacts; 72 households (56.7%) had member(s) with secondary infections. SIRs were not significantly higher for Alpha (61.0% [95% confidence interval (CI) 52.4-69.0%]) than non-Alpha (55.6% [CI 44.7-65.9%], P = 0.49). In households with Alpha, persons who identified as Asian or Hispanic/Latino had significantly higher SIRs than those who identified as White (P = 0.01 and 0.03, respectively). Close contact (e.g., kissing, hugging) with primary cases was associated with increased transmission for all lineages. Persons with Alpha infection were more likely to report constitutional symptoms than persons with non-Alpha (86.9% vs. 76.8%, P = 0.05). CONCLUSIONS: Household SIRs were similar for Alpha and non-Alpha. Comparable SIRs may be due to saturation of transmission risk in households owing to extensive close contact, or true lack of difference in transmission rates. Avoiding close contact within households may reduce SARS-CoV-2 transmission for all lineages among household members. |
Assessment of the Chad guinea worm surveillance information system: A pivotal foundation for eradication
Karki S , Weiss A , Dcruz J , Hunt D , Haigood B , Ouakou PT , Chop E , Zirimwabagabo H , Rubenstein BL , Yerian S , Roy SL , Kamb ML , Guagliardo SAJ . PLoS Negl Trop Dis 2021 15 (8) e0009675 BACKGROUND: In the absence of a vaccine or pharmacological treatment, prevention and control of Guinea worm disease is dependent on timely identification and containment of cases to interrupt transmission. The Chad Guinea Worm Eradication Program (CGWEP) surveillance system detects and monitors Guinea worm disease in both humans and animals. Although Guinea worm cases in humans has declined, the discovery of canine infections in dogs in Chad has posed a significant challenge to eradication efforts. A foundational information system that supports the surveillance activities with modern data management practices is needed to support continued program efficacy. METHODS: We sought to assess the current CGWEP surveillance and information system to identify gaps and redundancies and propose system improvements. We reviewed documentation, consulted with subject matter experts and stakeholders, inventoried datasets to map data elements and information flow, and mapped data management processes. We used the Information Value Cycle (IVC) and Data-Information System-Context (DISC) frameworks to help understand the information generated and identify gaps. RESULTS: Findings from this study identified areas for improvement, including the need for consolidation of forms that capture the same demographic variables, which could be accomplished with an electronic data capture system. Further, the mental models (conceptual frameworks) IVC and DISC highlighted the need for more detailed, standardized workflows specifically related to information management. CONCLUSIONS: Based on these findings, we proposed a four-phased roadmap for centralizing data systems and transitioning to an electronic data capture system. These included: development of a data governance plan, transition to electronic data entry and centralized data storage, transition to a relational database, and cloud-based integration. The method and outcome of this assessment could be used by other neglected tropical disease programs looking to transition to modern electronic data capture systems. |
Linked surveillance and genetic data uncovers programmatically relevant geographic scale of Guinea worm transmission in Chad.
Ribado JV , Li N , Thiele E , Lyons H , Cotton JA , Weiss A , Tchindebet Ouakou P , Moundai T , Zirimwabagabo H , Guagliardo SAJ , Chabot-Couture G , Proctor JL . PLoS Negl Trop Dis 2021 15 (7) e0009609 BACKGROUND: Guinea worm (Dracunculus medinensis) was detected in Chad in 2010 after a supposed ten-year absence, posing a challenge to the global eradication effort. Initiation of a village-based surveillance system in 2012 revealed a substantial number of dogs infected with Guinea worm, raising questions about paratenic hosts and cross-species transmission. METHODOLOGY/PRINCIPAL FINDINGS: We coupled genomic and surveillance case data from 2012-2018 to investigate the modes of transmission between dog and human hosts and the geographic connectivity of worms. Eighty-six variants across four genes in the mitochondrial genome identified 41 genetically distinct worm genotypes. Spatiotemporal modeling revealed worms with the same genotype ('genetically identical') were within a median range of 18.6 kilometers of each other, but largely within approximately 50 kilometers. Genetically identical worms varied in their degree of spatial clustering, suggesting there may be different factors that favor or constrain transmission. Each worm was surrounded by five to ten genetically distinct worms within a 50 kilometer radius. As expected, we observed a change in the genetic similarity distribution between pairs of worms using variants across the complete mitochondrial genome in an independent population. CONCLUSIONS/SIGNIFICANCE: In the largest study linking genetic and surveillance data to date of Guinea worm cases in Chad, we show genetic identity and modeling can facilitate the understanding of local transmission. The co-occurrence of genetically non-identical worms in quantitatively identified transmission ranges highlights the necessity for genomic tools to link cases. The improved discrimination between pairs of worms from variants identified across the complete mitochondrial genome suggests that expanding the number of genomic markers could link cases at a finer scale. These results suggest that scaling up genomic surveillance for Guinea worm may provide additional value for programmatic decision-making critical for monitoring cases and intervention efficacy to achieve elimination. |
Surveillance of Human Guinea Worm in Chad, 2010-2018
Guagliardo SAJ , Ruiz-Tiben E , Hopkins DR , Weiss AJ , Ouakou PT , Zirimwabagabo H , Unterwegner K , Tindall D , Cama VA , Bishop H , Sapp SGH , Roy SL . Am J Trop Med Hyg 2021 105 (1) 188-195 The total number of Guinea worm cases has been reduced by 99.9% since the mid-1980s when the eradication campaign began. Today, the greatest number of cases is reported from Chad. In this report, we use surveillance data collected by the Chad Guinea Worm Eradication Program to describe trends in human epidemiology. In total, 114 human cases were reported during the years 2010-2018, with highest rates of containment (i.e., water contamination prevented) in the years 2013, 2014, 2016, and 2017 (P < 0.0001). Approximately half of case-patients were female, and 65.8% of case-patients were aged 30 years or younger (mean: 26.4 years). About 34.2% of case-patients were farmers. Cases were distributed across many ethnicities, with a plurality of individuals being of the Sara Kaba ethnicity (21.3%). Most cases occurred between the end of June and the end of August and were clustered in the Chari Baguirmi (35.9%) and Moyen Chari regions (30.1%). Cases in the northern Chari River area peaked in April and in August, with no clear pattern in the southern Chari River area. History of travel within Chad was reported in 7.0% of cases, and male subjects (12.5%) were more likely than female subjects (1.7%) to have reported a history of travel (P = 0.03). Our findings confirm that human Guinea worm is geographically disperse and rare. Although the proportion of case-patients with travel history is relatively small, this finding highlights an additional challenge of surveillance in mobile populations in the final stages of the global eradication campaign. |
Cruise ship travel in the era of COVID-19: A summary of outbreaks and a model of public health interventions.
Guagliardo SAJ , Prasad PV , Rodriguez A , Fukunaga R , Novak RT , Ahart L , Reynolds J , Griffin I , Wiegand R , Quilter LAS , Morrison S , Jenkins K , Wall HK , Treffiletti A , White SB , Regan J , Tardivel K , Freeland A , Brown C , Wolford H , Johansson MA , Cetron MS , Slayton RB , Friedman CR . Clin Infect Dis 2021 74 (3) 490-497 BACKGROUND: Cruise travel contributed to SARS-CoV-2 transmission when there were relatively few cases in the United States. By March 14, 2020, the Centers for Disease Control and Prevention (CDC) issued a No Sail Order suspending U.S. cruise operations; the last U.S. passenger ship docked on April 16. METHODS: We analyzed SARS-CoV-2 outbreaks on cruises in U.S. waters or carrying U.S. citizens and used regression models to compare voyage characteristics. We used compartmental models to simulate the potential impact of four interventions (screening for COVID-19 symptoms; viral testing on two days and isolation of positive persons; reduction of passengers by 40%, crew by 20%, and port visits to one) for 7-day and 14-day voyages. RESULTS: During January 19-April 16, 2020, 89 voyages on 70 ships had known SARS-CoV-2 outbreaks; 16 ships had recurrent outbreaks. There were 1,669 RT-PCR-confirmed SARS-CoV-2 infections and 29 confirmed deaths. Longer voyages were associated with more cases (adjusted incidence rate ratio, 1.10, 95% CI: 1.03-1.17, p < 0.0001). Mathematical models showed that 7-day voyages had about 70% fewer cases than 14-day voyages. On 7-day voyages, the most effective interventions were reducing the number of individuals onboard (43-49% reduction in total infections) and testing passengers and crew (42-43% reduction in total infections). All four interventions reduced transmission by 80%, but no single intervention or combination eliminated transmission. Results were similar for 14-day voyages. CONCLUSIONS: SARS-CoV-2 outbreaks on cruises were common during January-April 2020. Despite all interventions modeled, cruise travel still poses a significant SARS-CoV-2 transmission risk. |
Clinical, diagnostic, and epidemiological features of a community-wide outbreak of canine leptospirosis in a low-prevalence region (Maricopa County, Arizona)
Iverson SA , Levy C , Yaglom HD , Venkat HL , Artus A , Galloway R , Guagliardo SAJ , Reynolds L , Kretschmer MJ , LaFerla Jenni ME , Woodward P , Reindel AA , Tarrant S , Sylvester T , Klein R , Mundschenk P , Sunenshine R , Schafer IJ . J Am Vet Med Assoc 2021 258 (6) 616-629 OBJECTIVE: To describe clinical, diagnostic, and epidemiological features of an outbreak of leptospirosis in dogs in Maricopa County, Ariz, from January 2016 through June 2017. ANIMALS: 71 case and 281 control dogs. PROCEDURES: Cases were classified as confirmed, probable, suspect, or not a case on the basis of medical record data that fulfilled clinical, diagnostic, and epidemiological criteria. Potential exposures were assessed by owner survey. For the case-control investigation, control dogs were recruited through owner completion of a July 2017 survey. Summary statistics and ORs for case dog lifestyle factors were reported. RESULTS: 54 dogs were classified as confirmed and 17 as probable cases. For 4 dogs of a household cluster (5 confirmed and 3 probable), the highest microscopic agglutination titer was for serovar Djasiman (Leptospira kirschneri detected by PCR assay), and for 13 dogs of a community outbreak (49 confirmed and 14 probable cases), the highest titer was for serovar Canicola (Leptospira interrogans detected by PCR assay). The 44 case dogs included in the case-control investigation were 7.7 (95% CI, 3.5 to 16.7) and 2.9 times (95% CI, 1.3 to 6.6) as likely as control dogs to have visited dog daycare or to have been kenneled overnight at a boarding facility, respectively, 30 days prior to the onset of clinical signs or diagnosis. CONCLUSIONS AND CLINICAL RELEVANCE: Diagnostic and epidemiological findings indicated 2 outbreaks. Transmission where dogs congregated likely propagated the community outbreak. Outbreaks of leptospiral infections can occur in regions of low prevalence, and a dog's exposure to areas where dogs congregate should be considered when making Leptospira vaccination recommendations. |
Myopericarditis Associated With Smallpox Vaccination Among US Army Personnel - Fort Hood, Texas, 2018
Mandra AM , Superior MJ , Guagliardo SAJ , Hesse E , Pacha LA , Stidham RA , Colbeck DC , Hrncir DE , Hall N , Petersen BW , Rao AK . Disaster Med Public Health Prep 2021 16 (3) 1-7 OBJECTIVE: In March 2018, the US Department of Defense (DOD) added the smallpox vaccination, using ACAM2000, to its routine immunizations, increasing the number of persons receiving the vaccine. The following month, Fort Hood reported a cluster of 5 myopericarditis cases. The Centers for Disease Control and Prevention and the DOD launched an investigation. METHODS: The investigation consisted of a review of medical records, establishment of case definitions, causality assessment, patient interviews, and active surveillance. A 2-sided exact rate ratio test was used to compare myopericarditis incidence rates. RESULTS: This investigation identified 4 cases of probable myopericarditis and 1 case of suspected myopericarditis. No alternative etiology was identified as a cause. No additional cases were identified. There was no statistically significant difference in incidence rates between the observed cluster (5.23 per 1000 vaccinated individuals, 95% CI: 1.7-12.2) and the ACAM2000 clinical trial outcomes for symptomatic persons, which was 2.29 per 1000 vaccinated individuals (95% CI: 0.3-8.3). CONCLUSIONS: Vaccination with ACAM2000 is the presumptive cause of this cluster. Caution should be exercised before considering vaccination campaigns for smallpox given the clinical morbidity and costs incurred by a case of myopericarditis. Risk of myopericarditis should be carefully weighed with risk of exposure to smallpox. |
Community-based Guinea worm surveillance in Chad: Evaluating a system at the intersection of human and animal disease
Rubenstein BL , Roy SL , Unterwegner K , Yerian S , Weiss A , Zirimwabagabo H , Chop E , Romero M , Ouakou PT , Moundai T , Guagliardo SAJ . PLoS Negl Trop Dis 2021 15 (3) e0009285 BACKGROUND: Guinea worm is a debilitating parasitic infection targeted for eradication. Annual human cases have dropped from approximately 3,500,000 in 1986 to 54 in 2019. Recent identification of canine cases in Chad threatens progress, and therefore detection, prevention, and containment of canine cases is a priority. We investigated associations between disease knowledge, community engagement, and canine cases in Chad to identify opportunities to improve active surveillance. METHODS: We surveyed 627 respondents (villagers, local leaders, community volunteers, and supervisors) across 45 villages under active surveillance. Descriptive statistics were analyzed by respondent category. Logistic regression models were fitted to assess the effects of volunteer visit frequency on villager knowledge. RESULTS: Knowledge increased with respondents' associations with the Guinea worm program. Household visit frequency by community volunteers was uneven: 53.0% of villagers reported visits at least twice weekly and 21.4% of villagers reported never being visited. Villagers visited by a volunteer at least twice weekly had better knowledge of Guinea worm symptoms (OR: 1.71; 95% CI: 1.04-2.79) and could name more prevention strategies (OR: 2.04; 95% CI: 1.32-3.15) than villagers visited less frequently. The primary motivation to report was to facilitate care-seeking for people with Guinea worm. Knowledge of animal "containment" to prevent contamination of water, knowledge of rewards for reporting animal cases, and ability to name any reasons to report Guinea worm were each positively correlated with village canine case counts. CONCLUSIONS: Community volunteers play crucial roles in educating their neighbors about Guinea worm and facilitating surveillance. Additional training and more attentive management of volunteers and supervisors could increase visit frequency and further amplify their impact. Emphasizing links between animal and human cases, the importance of animal containment, and animal rewards might improve surveillance and canine case detection. The surveillance system should be evaluated routinely to expand generalizability of data and monitor changes over time. |
Correlates of variation in Guinea worm burden among infected domestic dogs
Guagliardo SAJ , Wiegand R , Roy SL , Cleveland CA , Zirimwabagabo H , Chop E , Tchindebet Ouakou P , Ruiz-Tiben E , Hopkins D , Weiss A . Am J Trop Med Hyg 2021 104 (4) 1418-1424 The Guinea Worm Eradication Program has been extraordinarily successful-in 2019, there were 53 human cases reported, down from the estimated 3.5 million in 1986. Yet the occurrence of guinea worm in dogs is a challenge to eradication efforts, and underlying questions about transmission dynamics remain. We used routine surveillance data to run negative binomial regressions predicting worm burden among infected dogs in Chad. Of 3,371 infected dogs reported during 2015-2018, 38.5% had multiple worms. A multivariable model showed that the number of dogs in the household was negatively associated with worm burden (adjusted incidence rate ratio [AIRR] = 0.95, 95% CI: 0.93-0.97, P < 0.0001) after adjusting for dog age (AIRR = 0.99, 95% CI: 0.96-1.01, P > 0.1). This could relate to the amount of infective inocula (e.g., contaminated food or water) shared by multiple dogs in a household. Other significant univariable associations with worm burden included dog history of guinea worm infection (IRR = 1.30, 95% CI: 1.18-1.45) and dog owners who were hunters (IRR = 0.78, 95% CI: 0.62-0.99, P < 0.05) or farmers (IRR = 0.83, 95% CI: 0.77-0.90, P < 0.0001). Further analysis showed that the number of dogs in the household was significantly and positively correlated with nearly all other independent variables (e.g., owner occupation: farmer, fisherman, or hunter; dog age, gender, and history of guinea worm). The associations we identified between worm burden and dogs per household, and dogs per household and owner characteristics should be further investigated with more targeted studies. |
Guinea worm in domestic dogs in Chad: A description and analysis of surveillance data
Guagliardo SAJ , Roy SL , Ruiz-Tiben E , Zirimwabagabo H , Romero M , Chop E , Ouakou PT , Hopkins DR , Weiss AJ . PLoS Negl Trop Dis 2020 14 (5) e0008207 After a ten-year absence of reported Guinea worm disease in Chad, human cases were rediscovered in 2010, and canine cases were first recorded in 2012. In response, active surveillance for Guinea worm in both humans and animals was re-initiated in 2012. As of 2018, the Chad Guinea Worm Eradication Program (CGWEP) maintains an extensive surveillance system that operates in 1,895 villages, and collects information about worms, hosts (animals and humans), and animal owners. This report describes in detail the CGWEP surveillance system and explores epidemiological trends in canine Guinea worm cases during 2015-2018. Our results showed an increased in the number of canine cases detected by the system during the period of interest. The proportion of worms that were contained (i.e., water contamination was prevented) improved significantly over time, from 72.8% in 2015 to 85.7% in 2018 (Mantel-Haenszel chi-square = 253.3, P < 0.0001). Additionally, approximately 5% of owners of infected dogs reported that the dog had a Guinea worm-like infection earlier that year; 12.6% had a similar worm in a previous year. The proportion of dogs with a history of infection in a previous year increased over time (Mantel-Haenszel chi-square = 18.8, P < 0.0001). Canine cases were clustered in space and time: most infected dogs (80%) were from the Chari Baguirmi (38.1%) and Moyen Chari Regions (41.9%), and for each year the peak month of identified canine cases was June, with 78.5% occurring during March through August. Findings from this report evoke additional questions about why some dogs are repeatedly infected. Our results may help to target interventions and surveillance efforts in terms of space, time, and dogs susceptible to recurrent infection, with the ultimate goal of Guinea worm eradication. |
Do monkeypox exposures vary by ethnicity Comparison of Aka- and Bantu-suspected monkeypox cases
Guagliardo SAJ , Doshi RH , Reynolds MG , Dzabatou-Babeaux A , Ndakala N , Moses C , McCollum AM , Petersen BW . Am J Trop Med Hyg 2019 102 (1) 202-205 In 2017, a monkeypox outbreak occurred in Likouala Department, Republic of the Congo. Many of the affected individuals were of Aka ethnicity, hunter-gatherers indigenous to Central Africa who have worse health outcomes in comparison with other forest-dwelling peoples. To test the hypothesis that Aka people have different risk factors for monkeypox, we analyzed questionnaire data for 39 suspected cases, comparing Aka and Bantu groups. Aka people were more likely to touch animal urine/feces, find dead animals in/around the home, eat an animal that was found dead, or to have been scratched or bitten by an animal (P < 0.05, all variables). They were also more likely to visit the forest >/= once/week, sleep outside, or sleep on the ground (P < 0.001, all variables), providing opportunities for contact with monkeypox reservoirs during the night. The Aka and possibly other vulnerable groups may warrant special attention during educational and health promotion programs. |
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