Last data update: Mar 17, 2025. (Total: 48910 publications since 2009)
Records 1-16 (of 16 Records) |
Query Trace: Martel LD[original query] |
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Revisiting the minimum incubation period of Zaire ebolavirus
Kofman AD , Haberling DL , Mbuyi G , Martel LD , Whitesell AN , Van Herp M , Makaya G , Corvil S , Abedi AA , Ngoma PM , Mbuyi F , Mossoko M , Koivogui E , Soke N , Gbamou N , Fonjungo PN , Keita L , Keita S , Shoemaker TR , Richards GA , Montgomery JM , Breman JG , Geisbert TW , Choi MJ , Rollin PE . Lancet Infect Dis 2023 23 (10) 1111-1112 Ebola virus disease (EVD) caused by Ebola virus species Zaire ebolavirus (EBOV) is a major global health challenge causing sporadic outbreaks with high mortality. The minimum incubation period of EBOV, or the time from infection with the virus to the development of first symptoms, is thought to be 2 days and was initially established during the first EVD investigation in 1976.1 A published observation from the investigation noted that, “in one case of the disease, the only possible source of infection was contact with a probable case 48 hours before the latter developed symptoms”, and this observation was restated in another publication.2, 3 However, concluding that the minimum incubation period for EBOV is 2 days based on these reports is flawed for several reasons. First, the presumed source of the infection was a probable case of EVD and was not laboratory-confirmed; it is therefore uncertain whether the source truly had EVD. Second, since the report describes the contact between the source and the case occurring before the source developed symptoms, this implies asymptomatic transmission, which has been established to not occur with EBOV.4, 5, 6 Finally, the report's description of 48 h refers to the time between the case's contact with the alleged source and the source's onset of symptoms, which is itself not an incubation period. |
Lessons learned for surveillance system strengthening through capacity building and partnership engagement in post-Ebola Guinea, 2015-2019
Hemingway-Foday JJ , Diallo BI , Compaore S , Bah S , Keita S , Diallo IT , Martel LD , Standley CJ , Bah MB , Bah M , Camara D , Kaba AK , Keita L , Kone M , Reynolds E , Souare O , Stolka KB , Tchwenko S , Wone A , Worrell MC , MacDonald PDM . Front Public Health 2022 10 715356 The 2014-2016 Ebola outbreak in Guinea revealed systematic weaknesses in the existing disease surveillance system, which contributed to delayed detection, underreporting of cases, widespread transmission in Guinea and cross-border transmission to neighboring Sierra Leone and Liberia, leading to the largest Ebola epidemic ever recorded. Efforts to understand the epidemic's scale and distribution were hindered by problems with data completeness, accuracy, and reliability. In 2017, recognizing the importance and usefulness of surveillance data in making evidence-based decisions for the control of epidemic-prone diseases, the Guinean Ministry of Health (MoH) included surveillance strengthening as a priority activity in their post-Ebola transition plan and requested the support of partners to attain its objectives. The U.S. Centers for Disease Control and Prevention (US CDC) and four of its implementing partners-International Medical Corps, the International Organization for Migration, RTI International, and the World Health Organization-worked in collaboration with the Government of Guinea to strengthen the country's surveillance capacity, in alignment with the Global Health Security Agenda and International Health Regulations 2005 objectives for surveillance and reporting. This paper describes the main surveillance activities supported by US CDC and its partners between 2015 and 2019 and provides information on the strategies used and the impact of activities. It also discusses lessons learned for building sustainable capacity and infrastructure for disease surveillance and reporting in similar resource-limited settings. |
Evaluation of the first two frontline cohorts of the field epidemiology training program in Guinea, West Africa
Collins D , Diallo BI , Bah MB , Bah M , Standley CJ , Corvil S , Martel LD , MacDonald PDM . Hum Resour Health 2022 20 (1) 40 BACKGROUND: The 2014-2016 Ebola virus disease outbreak in West Africa revealed weaknesses in the health systems of the three most heavily affected countries, including a shortage of public health professionals at the local level trained in surveillance and outbreak investigation. In response, the Frontline Field Epidemiology Training Program (FETP) was created by CDC in 2015 as a 3-month, accelerated training program in field epidemiology that specifically targets the district level. In Guinea, the first two FETP-Frontline cohorts were held from January to May, and from June to September 2017. Here, we report the results of a cross-sectional evaluation of these first two cohorts of FETP-Frontline in Guinea. METHODS: The evaluation was conducted in April 2018 and consisted of interviews with graduates, their supervisors, and directors of nearby health facilities, as well as direct observation of data reports and surveillance tools at health facilities. Interviews and site visits were conducted using standardized questionnaires and checklists. Qualitative data were coded under common themes and analyzed using descriptive statistics. RESULTS: The evaluation revealed a significant perception of improvement in all assessed skills by the graduates, as well as high levels of self-reported involvement in key activities related to data collection, analysis, and reporting. Supervisors highlighted improvements to systematic and quality case and summary reporting as key benefits of the FETP-Frontline program. At the health facility level, staff reported the training had resulted in improvements to information sharing and case notifications. Reported barriers included lack of transportation, available support personnel, and other resources. Graduates and supervisors both emphasized the importance of continued and additional training to solidify and retain skills. CONCLUSIONS: The evaluation demonstrated a strongly positive perceived benefit of the FETP-Frontline training on the professional activities of graduates as well as the overall surveillance system. However, efforts are needed to ensure greater gender equity and to recruit more junior trainee candidates for future cohorts. Moreover, although improvements to the surveillance system were observed concurrent with the completion of the two cohorts, the evaluation was not designed to directly measure impact on surveillance or response functions. Combined with the rapid implementation of FETP-Frontline around the world, this suggests an opportunity to develop standardized evaluation toolkits, which could incorporate metrics that would directly assess the impact of equitable field epidemiology workforce development on countries' abilities to prevent, detect, and respond to public health threats. |
Implementation of DHIS2 for Disease Surveillance in Guinea: 2015-2020.
Reynolds E , Martel LD , Bah MO , Bah M , Bah MB , Boubacar B , Camara N , Camara YB , Corvil S , Diallo BI , Diallo IT , Diallo MK , Diallo MT , Diallo T , Guilavogui S , Hemingway-Foday JJ , Hann F , Kaba A , Kaba AK , Kande M , Lamarana DM , Middleton K , Sidibe N , Souare O , Standley CJ , Stolka KB , Tchwenko S , Worrell MC , MacDonald PDM . Front Public Health 2021 9 761196 ![]() A robust epidemic-prone disease surveillance system is a critical component of public health infrastructure and supports compliance with the International Health Regulations (IHR). One digital health platform that has been implemented in numerous low- and middle-income countries is the District Health Information System Version 2 (DHIS2). In 2015, in the wake of the Ebola epidemic, the Ministry of Health in Guinea established a strategic plan to strengthen its surveillance system, including adoption of DHIS2 as a health information system that could also capture surveillance data. In 2017, the DHIS2 platform for disease surveillance was piloted in two regions, with the aim of ensuring the timely availability of quality surveillance data for better prevention, detection, and response to epidemic-prone diseases. The success of the pilot prompted the national roll-out of DHIS2 for weekly aggregate disease surveillance starting in January 2018. In 2019, the country started to also use the DHIS2 Tracker to capture individual cases of epidemic-prone diseases. As of February 2020, for aggregate data, the national average timeliness of reporting was 72.2%, and average completeness 98.5%; however, the proportion of individual case reports filed was overall low and varied widely between diseases. While substantial progress has been made in implementation of DHIS2 in Guinea for use in surveillance of epidemic-prone diseases, much remains to be done to ensure long-term sustainability of the system. This paper describes the implementation and outcomes of DHIS2 as a digital health platform for disease surveillance in Guinea between 2015 and early 2020, highlighting lessons learned and recommendations related to the processes of planning and adoption, pilot testing in two regions, and scale up to national level. |
Public health emergency management capacity building in Guinea: 2014-2019
Martel LD , Phipps M , Traore A , Standley CJ , Soumah ML , Lamah A , Wone A , Asima M , Barry AM , Berete M , Attal-Juncqua A , Katz R , Robert A , Sompare I , Sorrell EM , Toure Y , Morel-Vulliez A , Keita S . Int J Emerg Manag 2020 16 (2) 179-200 Before the Ebola virus disease (EVD) outbreak of 2014-2016, Guinea did not have an emergency management system in place. During the outbreak, Global Health Security Agenda (GHSA) 2014-2019 funds made it possible to rapidly improve the country's capacity to manage epidemics through the development of public health emergency operation centres (PHEOCs) at the national and district levels. Since the end of the response, the infrastructure, staff, and systems of these PHEOCs have been further reinforced and well-integrated in the daily activities of Guinea's National Agency for Health Security, the entity responsible for the management of epidemics. The development of PHEOCs as emergency management tools for epidemics in Guinea would not have been possible without a strong endorsement within the Ministry of Health. Guinea's PHEOC network is wellpositioned to serve as a model of excellence for other Ministries in Guinea and Ministries of Health of other countries of West Africa. |
Leveraging partnerships to maximize global health security improvements in Guinea, 2015-2019
Standley CJ , MacDonald PDM , Attal-Juncqua A , Barry AM , Bile EC , Collins DL , Corvil S , Ibrahima DB , Hemingway-Foday JJ , Katz R , Middleton KJ , Reynolds EM , Sorrell EM , Lamine SM , Wone A , Martel LD . Health Secur 2020 18 S34-s42 In response to the 2014-2016 West Africa Ebola virus disease (EVD) outbreak, a US congressional appropriation provided funds to the US Centers for Disease Control and Prevention (CDC) to support global health security capacity building in 17 partner countries, including Guinea. The 2014 funding enabled CDC to provide more than 300 deployments of personnel to Guinea during the Ebola response, establish a country office, and fund 11 implementing partners through cooperative agreements to support global health security engagement efforts in 4 core technical areas: workforce development, surveillance systems, laboratory systems, and emergency management. This article reflects on almost 4 years of collaboration between CDC and its implementing partners in Guinea during the Ebola outbreak response and the recovery period. We highlight examples of collaborative synergies between cooperative agreement partners and local Guinean partners and discuss the impact of these collaborations in strengthening the above 4 core capacities. Finally, we identify the key elements of the successful collaborations, including communication and information sharing as a core cooperative agreement activity, a flexible funding mechanism, and willingness to adapt to local needs. We hope these observations can serve as guidance for future endeavors seeking to establish strong and effective partnerships between government and nongovernment organizations providing technical and operational assistance. |
Long-distance effects of epidemics: Assessing the link between the 2014 West Africa Ebola outbreak and U.S. exports and employment
Kostova D , Cassell CH , Redd JT , Williams DE , Singh T , Martel LD , Bunnell RE . Health Econ 2019 28 (11) 1248-1261 Although the economic consequences of epidemic outbreaks to affected areas are often well documented, little is known about how these might carry over into the economies of unaffected regions. In the absence of direct pathogen transmission, global trade is one mechanism through which geographically distant epidemics could reverberate to unaffected countries. This study explores the link between global public health events and U.S. economic outcomes by evaluating the role of the 2014 West Africa Ebola outbreak in U.S. exports and exports-supported U.S. jobs, 2005-2016. Estimates were obtained using difference-in-differences models where sub-Saharan Africa countries were assigned to treatment and comparison groups based on their Ebola transmission status, with controls for observed and unobserved time-variant factors that may independently influence trends in trade. Multiple model specification checks were performed to ensure analytic robustness. The year of peak transmission, 2014, was estimated to result in $1.08 billion relative reduction in U.S. merchandise exports to Ebola-affected countries, whereas estimated losses in exports-supported U.S. jobs exceeded 1,200 in 2014 and 11,000 in 2015. These findings suggest that remote disruptions in health security might play a role in U.S. economic indicators, demonstrating the interconnectedness between global health and aspects of the global economy and informing the relevance of health security efforts. |
Creating a national specimen referral system in Guinea: Lessons from initial development and implementation
Standley CJ , Muhayangabo R , Bah MS , Barry AM , Bile E , Fischer JE , Heegaard W , Koivogui L , Lakiss SK , Sorrell EM , VanSteelandt A , Dahourou AG , Martel LD . Front Public Health 2019 7 83 In the wake of the 2014-2016, West Africa Ebola virus disease (EVD) outbreak, the Government of Guinea recognized an opportunity to strengthen its national laboratory system, incorporating capacity and investments developed during the response. The Ministry of Health (MOH) identified creation of a holistic, safe, secure, and timely national specimen referral system as a priority for improved detection and confirmation of priority diseases, in line with national Integrated Disease Surveillance and Response guidelines. The project consisted of two parts, each led by different implementing partners working collaboratively together and with the Ministry of Health: the development and approval of a national specimen referral policy, and pilot implementation of a specimen referral system, modeled on the policy, in three prefectures. This paper describes the successful execution of the project, highlighting the opportunities and challenges of building sustainable health systems capacity during and after public health emergencies, and provides lessons learned for strengthening national capabilities for surveillance and disease diagnosis. |
Assessing health systems in Guinea for prevention and control of priority zoonotic diseases: A One Health approach
Standley CJ , Carlin EP , Sorrell EM , Barry AM , Bile E , Diakite AS , Keita MS , Koivogui L , Mane S , Martel LD , Katz R . One Health 2019 7 100093 To guide One Health capacity building efforts in the Republic of Guinea in the wake of the 2014-2016 Ebola virus disease (EVD) outbreak, we sought to identify and assess the existing systems and structures for zoonotic disease detection and control. We partnered with the government ministries responsible for human, animal, and environmental health to identify a list of zoonotic diseases - rabies, anthrax, brucellosis, viral hemorrhagic fevers, trypanosomiasis and highly pathogenic avian influenza - as the country's top priorities. We used each priority disease as a case study to identify existing processes for prevention, surveillance, diagnosis, laboratory confirmation, reporting and response across the three ministries. Results were used to produce disease-specific systems "maps" emphasizing linkages across the systems, as well as opportunities for improvement. We identified brucellosis as a particularly neglected condition. Past efforts to build avian influenza capabilities, which had degraded substantially in less than a decade, highlighted the challenge of sustainability. We observed a keen interest across sectors to reinvigorate national rabies control, and given the regional and global support for One Health approaches to rabies elimination, rabies could serve as an ideal disease to test incipient One Health coordination mechanisms and procedures. Overall, we identified five major categories of gaps and challenges: (1) Coordination; (2) Training; (3) Infrastructure; (4) Public Awareness; and (5) Research. We developed and prioritized recommendations to address the gaps, estimated the level of resource investment needed, and estimated a timeline for implementation. These prioritized recommendations can be used by the Government of Guinea to plan strategically for future One Health efforts, ideally under the auspices of the national One Health Platform. This work demonstrates an effective methodology for mapping systems and structures for zoonotic diseases, and the benefit of conducting a baseline review of systemic capabilities prior to embarking on capacity building efforts. |
Operational evaluation of rapid diagnostic testing for Ebola Virus Disease in Guinean laboratories
VanSteelandt A , Aho J , Franklin K , Likofata J , Kamgang JB , Keita S , Koivogui L , Magassouba N , Martel LD , Dahourou AG . PLoS One 2017 12 (11) e0188047 BACKGROUND: Rapid Diagnostic Tests (RDTs) for Ebola Virus Disease (EVD) at the point of care have the potential to increase access and acceptability of EVD testing and the speed of patient isolation and secure burials for suspect cases. A pilot program for EVD RDTs in high risk areas of Guinea was introduced in October 2015. This paper presents concordance data between EVD RDTs and PCR testing in the field as well as an assessment of the acceptability, feasibility, and quality assurance of the RDT program. METHODS AND FINDINGS: Concordance data were compiled from laboratory surveillance databases. The operational measures of the laboratory-based EVD RDT program were evaluated at all 34 sentinel sites in Guinea through: (1) a technical questionnaire filled by the lab technicians who performed the RDTs, (2) a checklist filled by the evaluator during the site visits, and (3) direct observation of the lab technicians performing the quality control test. Acceptability of the EVD RDT was good for technicians, patients, and families although many technicians (69.8%) expressed concern for their safety while performing the test. The feasibility of the program was good based on average technician knowledge scores (6.6 out of 8) but basic infrastructure, equipment, and supplies were lacking. There was much room for improvement in quality assurance of the program. CONCLUSIONS: The implementation of new diagnostics in weak laboratory systems requires general training in quality assurance, biosafety and communication with patients in addition to specific training for the new test. Corresponding capacity building in terms of basic equipment and a long-term commitment to transfer supervision and quality improvement to national public health staff are necessary for successful implementation. |
Assessments of Ebola knowledge, attitudes and practices in Forecariah, Guinea and Kambia, Sierra Leone, July-August 2015
Jalloh MF , Bunnell R , Robinson S , Jalloh MB , Barry AM , Corker J , Sengeh P , VanSteelandt A , Li W , Dafae F , Diallo AA , Martel LD , Hersey S , Marston B , Morgan O , Redd JT . Philos Trans R Soc Lond B Biol Sci 2017 372 (1721) The border region of Forecariah (Guinea) and Kambia (Sierra Leone) was of immense interest to the West Africa Ebola response. Cross-sectional household surveys with multi-stage cluster sampling procedure were used to collect random samples from Kambia (n = 635) in July 2015 and Forecariah (n = 502) in August 2015 to assess public knowledge, attitudes and practices related to Ebola. Knowledge of the disease was high in both places, and handwashing with soap and water was the most widespread prevention practice. Acceptance of safe alternatives to traditional burials was significantly lower in Forecariah compared with Kambia. In both locations, there was a minority who held discriminatory attitudes towards survivors. Radio was the predominant source of information in both locations, but those from Kambia were more likely to have received Ebola information from community sources (mosques/churches, community meetings or health workers) compared with those in Forecariah. These findings contextualize the utility of Ebola health messaging during the epidemic and suggest the importance of continued partnership with community leaders, including religious leaders, as a prominent part of future public health protection.This article is part of the themed issue 'The 2013-2016 West African Ebola epidemic: data, decision-making and disease control'. |
Risk factors for long-term post-traumatic stress disorder among medical rescue workers appointed to the 2008 Wenchuan earthquake response in China
Schenk EJ , Yuan J , Martel LD , Shi GQ , Han K , Gao X . Disasters 2016 41 (4) 788-802 This study aims to determine the risk factors for clinically-significant post-traumatic stress disorder (PTSD) among Chinese medical rescue workers one year after the response to the Wenchuan earthquake on 12 May 2008. A sample of 337 medical workers who performed response work within the first three months of the event completed an online questionnaire, which included information on demographics, social support, the management and organisation of the disaster response, and an assessment of PTSD. Symptoms consistent with PTSD were prevalent in 17 per cent of the rescue workers. Those who developed PTSD symptoms were more likely to have been injured, experienced a water shortage, been disconnected from family and friends during the response, and have passive coping styles and neurotic personalities. Factors that cannot be changed easily, such as personality traits, should be evaluated prior to deployment to ensure that rescue workers at higher risk of PTSD are provided with adequate support before and during deployment. |
Notes from the field: Baseline assessment of the use of Ebola rapid diagnostic tests - Forecariah, Guinea, October-November 2015
Huang JY , Louis FJ , Dixon MG , Sefu M , Kightlinger L , Martel LD , Jayaraman GC , Gueye AS . MMWR Morb Mortal Wkly Rep 2016 65 (12) 328-329 The Ebola virus disease (Ebola) epidemic in West Africa began in Guinea in early 2014. The reemergence of Ebola and risk of ongoing, undetected transmission continues because of the potential for sexual transmission and other as yet unknown transmission pathways. On March 17, 2016, two new cases of Ebola in Guinea were confirmed by the World Health Organization. This reemergence of Ebola in Guinea is the first since the original outbreak in the country was declared over on December 29, 2015. The prefecture of Forecariah, in western Guinea, was considerably affected by Ebola in 2015, with an incidence rate of 159 cases per 100,000 persons. Guinea also has a high prevalence of malaria; in a nationwide 2012 survey, malaria prevalence was reported to be 44% among healthy children aged ≤5 years. Malaria is an important reason for seeking health care; during 2014, 34% of outpatient consultations were related to malaria. |
Evaluation of a national call center and a local alerts system for detection of new cases of Ebola virus disease - Guinea, 2014-2015
Lee CT , Bulterys M , Martel LD , Dahl BA . MMWR Morb Mortal Wkly Rep 2016 65 (9) 227-230 The epidemic of Ebola virus disease (Ebola) in West Africa began in Guinea in late 2013 (1), and on August 8, 2014, the World Health Organization (WHO) declared the epidemic a Public Health Emergency of International Concern (2). Guinea was declared Ebola-free on December 29, 2015, and is under a 90 day period of enhanced surveillance, following 3,351 confirmed and 453 probable cases of Ebola and 2,536 deaths (3). Passive surveillance for Ebola in Guinea has been conducted principally through the use of a telephone alert system. Community members and health facilities report deaths and suspected Ebola cases to local alert numbers operated by prefecture health departments or to a national toll-free call center. The national call center additionally functions as a source of public health information by responding to questions from the public about Ebola. To evaluate the sensitivity of the two systems and compare the sensitivity of the national call center with the local alerts system, the CDC country team performed probabilistic record linkage of the combined prefecture alerts database, as well as the national call center database, with the national viral hemorrhagic fever (VHF) database; the VHF database contains records of all known confirmed Ebola cases. Among 17,309 alert calls analyzed from the national call center, 71 were linked to 1,838 confirmed Ebola cases in the VHF database, yielding a sensitivity of 3.9%. The sensitivity of the national call center was highest in the capital city of Conakry (11.4%) and lower in other prefectures. In comparison, the local alerts system had a sensitivity of 51.1%. Local public health infrastructure plays an important role in surveillance in an epidemic setting. |
Ebola virus disease - Sierra Leone and Guinea, August 2015
Hersey S , Martel LD , Jambai A , Keita S , Yoti Z , Meyer E , Seeman S , Bennett S , Ratto J , Morgan O , Akyeampong MA , Sainvil S , Worrell MC , Fitter D , Arnold KE . MMWR Morb Mortal Wkly Rep 2015 64 (35) 981-4 The Ebola virus disease (Ebola) outbreak in West Africa began in late 2013 in Guinea (1) and spread unchecked during early 2014. By mid-2014, it had become the first Ebola epidemic ever documented. Transmission was occurring in multiple districts of Guinea, Liberia, and Sierra Leone, and for the first time, in capital cities (2). On August 8, 2014, the World Health Organization (WHO) declared the outbreak to be a Public Health Emergency of International Concern (3). Ministries of Health, with assistance from multinational collaborators, have reduced Ebola transmission, and the number of cases is now declining. While Liberia has not reported a case since July 12, 2015, transmission has continued in Guinea and Sierra Leone, although the numbers of cases reported are at the lowest point in a year. In August 2015, Guinea and Sierra Leone reported 10 and four confirmed cases, respectively, compared with a peak of 526 (Guinea) and 1,997 (Sierra Leone) in November 2014. This report details the current situation in Guinea and Sierra Leone, outlines strategies to interrupt transmission, and highlights the need to maintain public health response capacity and vigilance for new cases at this critical time to end the outbreak. |
Guatemala's Ministry of Health Rapid Response Team manuals
Hernandez L , Hanson KM , Martel LD . Biosecur Bioterror 2014 12 (5) 292-7 The function of public health rapid response teams (RRTs) is to quickly identify, investigate, and control an outbreak before it can spread. The Central America Regional Office in Guatemala provided assistance to the Guatemalan Ministry of Health and Social Assistance (MSPAS) to develop RRT manuals at the district and regional levels. The manuals are divided into 4 sections: background, activity lists, standard operating procedures, and annexes. The manuals outline Guatemala's RRT members' responsibilities and will be tested in the near future through tabletop exercises. The development of the manuals is a concrete and significant step toward the attainment of Guatemala's IHR goals and should be integrated into a larger emergency management system to promote "a world safe and secure from global health threats posed by infectious diseases." |
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