Last data update: Apr 14, 2025. (Total: 49082 publications since 2009)
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Query Trace: Dahl BA[original query] |
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Costing approaches for vaccine-preventable disease surveillance: Lessons from Ethiopia and Nepal
Darwar R , Huang X , Abayeneh A , Alemayehu Beshah S , Patel MK , Dagnachew Zeleke E , Wossen M , Alayu M , Lisanwork L , Dahl BA , Wassie Asemahaegne E , Wang SH , Pallas SW , Abate E , Mwenda JM , Bose AS , Mejia N . Vaccine 2025 50 126776 INTRODUCTION: There is limited information about vaccine-preventable disease (VPD) surveillance cost. To address this gap, retrospective micro-costing studies of pre-COVID-19 pandemic VPD surveillance were conducted in Nepal and Ethiopia. Based on these evaluations-the sole cost evaluations on comprehensive VPD surveillance-this article provides methodological considerations and recommendations for other countries planning to conduct VPD surveillance costing studies to inform planning and budgeting. METHODS: The methods used for each study were systematically compared by key themes: costing perspective, cost categories, costing approach, allocation of shared costs, sampling criteria, extrapolation strategies, data collection, and analytic adjustments. For each theme, investigators identified methodologic challenges and potential strategies to address them, compared study methodologies to surveillance costing guidelines, and recommended practices for future such studies. RESULTS: The studies used similar perspectives and VPD inclusion criteria. Costs in Nepal were collected and analyzed by a subset of surveillance core and support functions, whereas the Ethiopia study categorized costs using surveillance support functions from the Global Strategy on Comprehensive VPD Surveillance. A mix of random and purposive sampling of surveillance sites was used in both studies. Surveillance sites were selected considering the strata of interest at each administrative level. Results from both studies were extrapolated country-wide using sampling weights and assumptions about the representativeness of purposively sampled units. DISCUSSION: The review highlighted potential methodologic tradeoffs in utility and precision of results based on the lessons learned from two country VPD surveillance cost studies. The advantages of collecting and using cost estimates by VPD surveillance core versus support function for program budgeting for varied audiences should be explored in future studies. Sampling strategies should be developed with consideration for the precision needed for the intended use of costing results. The resulting recommendations can improve and standardize the conduct and interpretation of future such studies. |
Study protocol for COVID-19 breakthrough infections and vaccine-induced immune response among a cohort of healthcare workers, Bangladesh
Hassan MZ , Basher AK , Rahman MZ , Bhuiyan TR , Chowdhury F , Hossain MK , Rahman A , Islam MN , MDuca L , Kaydos-Daniels SC , Dahl BA , Qadri F , Ortiz N . PLoS One 2024 19 (12) e0316121 ![]() BACKGROUND: To optimize vaccination strategies, it is useful to detect breakthrough infections and assess vaccine effectiveness in programmatic use. Monitoring emerging SARS-CoV-2 variants and vaccine effectiveness against them is also essential to determine the most effective vaccine options. This study aims to monitor SARS-CoV-2 breakthrough infections, the emergence of new SARS-CoV-2 variants, and host immune response during the peri-infection period of COVID-19. The study will also assess the uptake of the COVID-19 vaccine booster doses, and associated barriers or motivations among healthcare workers (HCWs). METHODS: Leveraging an existing HCW cohort in Bangladesh, HCWs will be enrolled from purposively selected health facilities from four different administrative divisions across Bangladesh. We captured cohort data on HCW's demographic information, clinical information, COVID-19 illness, and exposure, and vaccination histories for COVID-19. However, no biological specimens were collected for testing during the first phase of the cohort. In the current study, we plan to follow enrolled HCWs biweekly for suspected COVID-19 illness and capture relevant data including illness outcomes. Respiratory swab samples from symptomatic and a subset of asymptomatic HCWs will be tested for SARS-CoV-2 by rRT-PCR and positive samples will undergo Sanger sequencing to identify the SARS-CoV-2 variants of concern (VOCs). We will also perform Whole Genome Sequencing on a subset of SARS-CoV-2 positive samples with low CT values (Ct ≤ 30) to identify emerging SARS-CoV-2 variants. To examine the antibody response, we will collect blood samples from the participants at 12-week intervals for one year. We will use the EUROIMMUN kit and will also perform in-house ELISA to assess host immune factors with Luminex platform. DISCUSSION: This proposed study will generate useful data on COVID-19 breakthrough infection and the durability of anti-SARS-CoV-2 antibodies among HCWs following vaccination. The findings on booster vaccination intention and uptake will inform government COVID-19 vaccination strategies. Information on circulating and emerging strains of SARS-CoV-2 and vaccine performance against those strains will help understand population-level risks of COVID-19 infection. The study will generate data on facilitators and barriers to COVID-19 booster uptake among HCWs which can inform health communication messaging to improve booster acceptance in this population. |
COVID-19 vaccination coverage - World Health Organization African Region, 2021-2023
Doshi RH , Nsasiirwe S , Dahlke M , Atagbaza A , Aluta OE , Tatsinkou AB , Dauda E , Vilajeliu A , Gurung S , Tusiime J , Braka F , Bwaka A , Wanyoike S , Brooks DJ , Blanc DC , Alexander JP Jr , Dahl BA , Lindstrand A , Wiysonge CS . MMWR Morb Mortal Wkly Rep 2024 73 (14) 307-311 With the availability of authorized COVID-19 vaccines in early 2021, vaccination became an effective tool to reduce COVID-19-associated morbidity and mortality. Initially, the World Health Organization (WHO) set an ambitious target to vaccinate 70% of the global population by mid-2022. However, in July 2022, WHO recommended that all countries, including those in the African Region, prioritize COVID-19 vaccination of high-risk groups, including older adults and health care workers, to have the greatest impact on morbidity and mortality. As of December 31, 2023, approximately 860 million doses of COVID-19 vaccine had been delivered to countries in the African Region, and 646 million doses had been administered. Cumulatively, 38% of the African Region's population had received ≥1 dose, 32% had completed a primary series, and 21% had received ≥1 booster dose. Cumulative total population coverage with ≥1 dose ranged by country from 0.3% to 89%. Coverage with the primary series among older age groups was 52% (range among countries = 15%-96%); primary series coverage among health care workers was 48% (range = 13%-99%). Although the COVID-19 public health emergency of international concern was declared over in May 2023, current WHO recommendations reinforce the need to vaccinate priority populations at highest risk for severe COVID-19 disease and death and build more sustainable programs by integrating COVID-19 vaccination into primary health care, strengthening immunization across the life course, and improving pandemic preparedness. |
Global VAX: A U.S. contribution to global COVID-19 vaccination efforts, 2021-2023
Dahl BA , Tritter B , Butryn D , Dahlke M , Browning S , Gelting R , Fleming M , Ortiz N , Labrador J , Novak R , Fitter D , Bell E , McGuire M , Rosenbaum R , Pulwer R , Wun J , McCaffrey A , Chowdhury M , Parks N , Cunningham M , Mounts A , Curry D , Richardson D , Grant G . Vaccine 2024 In December 2021 the U.S. Government announced a new, whole-of-government $1.8 billion effort, the Initiative for Global Vaccine Access (Global VAX) in response to the global COVID-19 pandemic. Using the foundation of decades of U.S. government investments in global health and working in close partnership with local governments and key global and multilateral organizations, Global VAX enabled the rapid acceleration of the global COVID-19 vaccine rollout in selected countries, contributing to increased COVID-19 vaccine coverage in some of the world's most vulnerable communities. Through Global VAX, the U.S. Government has supported 125 countries to scale up COVID-19 vaccine delivery and administration while strengthening primary health care systems to respond to future health crises. The progress made by Global VAX has paved the way for a stronger global recovery and improved global health security. |
Effects of COVID-19 on vaccine-preventable disease surveillance systems in the World Health Organization African Region, 2020
Bigouette JP , Callaghan AW , Donadel M , Porter AM , Rosencrans L , Lickness JS , Blough S , Li X , Perry RT , Williams AJ , Scobie HM , Dahl BA , McFarland J , Murrill CS . Emerg Infect Dis 2022 28 (13) S203-s207 Global emergence of the COVID-19 pandemic in 2020 curtailed vaccine-preventable disease (VPD) surveillance activities, but little is known about which surveillance components were most affected. In May 2021, we surveyed 214 STOP (originally Stop Transmission of Polio) Program consultants to determine how VPD surveillance activities were affected by the COVID-19 pandemic throughout 2020, primarily in low- and middle-income countries, where program consultants are deployed. Our report highlights the responses from 154 (96%) of the 160 consultants deployed to the World Health Organization African Region, which comprises 75% (160/214) of all STOP Program consultants deployed globally in early 2021. Most survey respondents observed that VPD surveillance activities were somewhat or severely affected by the COVID-19 pandemic in 2020. Reprioritization of surveillance staff and changes in health-seeking behaviors were factors commonly perceived to decrease VPD surveillance activities. Our findings suggest the need for strategies to restore VPD surveillance to prepandemic levels. |
Field investigation of high reported non-neonatal tetanus burden in Uganda, 2016-2017
Casey RM , Nguna J , Opar B , Ampaire I , Lubwama J , Tanifum P , Zhu BP , Kisakye A , Kabwongera E , Tohme RA , Dahl BA , Ridpath AD , Scobie HM . Int J Epidemiol 2023 52 (4) 1150-1162 BACKGROUND: Despite providing tetanus-toxoid-containing vaccine (TTCV) to infants and reproductive-age women, Uganda reports one of the highest incidences of non-neonatal tetanus (non-NT). Prompted by unusual epidemiologic trends among reported non-NT cases, we conducted a retrospective record review to see whether these data reflected true disease burden. METHODS: We analysed nationally reported non-NT cases during 2012-2017. We visited 26 facilities (14 hospitals, 12 health centres) reporting high numbers of non-NT cases (n = 20) or zero cases (n = 6). We identified non-NT cases in facility registers during 1 January 2016-30 June 2017; the identified case records were abstracted. RESULTS: During 2012-2017, a total of 24 518 non-NT cases were reported and 74% were ≥5 years old. The average annual incidence was 3.43 per 100 000 population based on inpatient admissions. Among 482 non-NT inpatient cases reported during 1 January 2016-30 June 2017 from hospitals visited, 342 (71%) were identified in facility registers, despite missing register data (21%). Males comprised 283 (83%) of identified cases and 60% were ≥15 years old. Of 145 cases with detailed records, 134 (92%) were clinically confirmed tetanus; among these, the case-fatality ratio (CFR) was 54%. Fourteen cases were identified at two hospitals reporting zero cases. Among >4000 outpatient cases reported from health centres visited, only 3 cases were identified; the remainder were data errors. CONCLUSIONS: A substantial number of non-NT cases and deaths occur in Uganda. The high CFR and high non-NT burden among men and older children indicate the need for TTCV booster doses across the life course to all individuals as well as improved coverage with the TTCV primary series. The observed data errors indicate the need for data quality improvement activities. |
Comprehensive vaccine-preventable disease surveillance in the Western Pacific Region: A literature review on integration of surveillance functions, 2000-2021
Donadel M , Scobie HM , Pastore R , Grabovac V , Batmunkh N , O'Connor S , Dahl BA , Murrill CS . Glob Health Sci Pract 2022 10 (5) INTRODUCTION: A strategic framework for 2021-2030 developed by the World Health Organization (WHO) Regional Office for the Western Pacific emphasizes the need for high-quality and integrated vaccine-preventable disease (VPD) surveillance. We conducted a literature review to document the barriers, enabling factors, and innovations for integrating surveillance functions for VPDs and other communicable diseases in Western Pacific Region (WPR) countries. METHODS: We searched published and gray literature on integrated VPD surveillance from 2000 to 2021. Articles in English, Spanish, or French were screened to identify those relating to VPD surveillance in a WPR country and not meeting defined exclusion criteria. We categorized articles using the 8 WHO surveillance support functions and abstracted data on the country; type of surveillance; and reported barriers, enabling factors, and best practices for integration. RESULTS: Of the 3,137 references screened, 87 met the eligibility criteria. Of the 8 surveillance support functions, the proportion of references that reported integration related to the laboratory was 56%, followed by workforce capacity (54%), governance (51%), data management and use (47%), field logistics and communication (47%), coordination (15%), program management (13%), and supervision (9%). Several references noted fragmented systems and a lack of coordination between units as barriers to integration, highlighting the importance of engagement across public health units and between the public and private sectors. The literature also indicated a need for interoperable information systems and revealed the use of promising new technologies for data reporting and laboratory testing. In some WPR countries, workforce capacity was strengthened at all administrative levels by the implementation of integrated trainings on data monitoring and use and on laboratory techniques applicable to multiple VPDs. CONCLUSION: This literature review supports integrating VPDs into broader communicable disease surveillance systems in WPR countries while ensuring that the minimal WHO-recommended standards for VPD surveillance are met. |
US Centers for Disease Control and Prevention and its partners' contributions to global health security
Tappero JW , Cassell CH , Bunnell RE , Angulo FJ , Craig A , Pesik N , Dahl BA , Ijaz K , Jafari H , Martin R . Emerg Infect Dis 2017 23 (13) S5-S14 To achieve compliance with the revised World Health Organization International Health Regulations (IHR 2005), countries must be able to rapidly prevent, detect, and respond to public health threats. Most nations, however, remain unprepared to manage and control complex health emergencies, whether due to natural disasters, emerging infectious disease outbreaks, or the inadvertent or intentional release of highly pathogenic organisms. The US Centers for Disease Control and Prevention (CDC) works with countries and partners to build and strengthen global health security preparedness so they can quickly respond to public health crises. This report highlights selected CDC global health protection platform accomplishments that help mitigate global health threats and build core, cross-cutting capacity to identify and contain disease outbreaks at their source. CDC contributions support country efforts to achieve IHR 2005 compliance, contribute to the international framework for countering infectious disease crises, and enhance health security for Americans and populations around the world. |
Using acute flaccid paralysis surveillance as a platform for vaccine-preventable disease surveillance
Wassilak SGF , Williams CL , Murrill CS , Dahl BA , Ohuabunwo C , Tangermann RH . J Infect Dis 2017 216 S293-S298 Surveillance for acute flaccid paralysis (AFP) is a fundamental cornerstone of the global polio eradication initiative (GPEI). Active surveillance (with visits to health facilities) is a critical strategy of AFP surveillance systems for highly sensitive and timely detection of cases. Because of the extensive resources devoted to AFP surveillance, multiple opportunities exist for additional diseases to be added using GPEI assets, particularly because there is generally 1 district officer responsible for all disease surveillance. For this reason, integrated surveillance has become a standard practice in many countries, ranging from adding surveillance for measles and rubella to integrated disease surveillance for outbreak-prone diseases (integrated disease surveillance and response). This report outlines the current level of disease surveillance integration in 3 countries (Nepal, India, and Nigeria) and proposes that resources continue for long-term maintenance in resource-poor countries of AFP surveillance as a platform for surveillance of vaccine-preventable diseases and other outbreak-prone diseases. |
Ebola virus persistence in breast milk after no reported illness: a likely source of virus transmission from mother to child.
Sissoko D , Keita M , Diallo B , Aliabadi N , Fitter DL , Dahl BA , Bore JA , Koundouno FR , Singethan K , Meisel S , Enkirch T , Mazzarelli A , Amburgey V , Faye O , Sall AA , Magassouba N , Carroll MW , Anglaret X , Malvy D , Formenty P , Aylward RB , Keita S , Djingarey MH , Loman NJ , Gunther S , Duraffour S . Clin Infect Dis 2016 64 (4) 513-516 ![]() A nine-month-old infant died from Ebola virus (EBOV) disease with unknown epidemiological link. While her parents did not report previous illness, laboratory investigations revealed persisting EBOV RNA in the mother's breast milk and the father's seminal fluid. Genomic analysis strongly suggests EBOV transmission to the child through breastfeeding. |
Ebola: anatomy of an epidemic
Lo TQ , Marston BJ , Dahl BA , De Cock KM . Annu Rev Med 2016 68 359-370 As of the end of March 2016, the West Africa epidemic of Ebola virus disease (Ebola) had resulted in a total of 28,646 cases, 11,323 of them fatal, reported to the World Health Organization. Guinea, Liberia, and Sierra Leone were most heavily affected, but Ebola cases were exported to several other African and European countries as well as the United States, with limited further transmission, including to healthcare workers. We review the descriptive epidemiology of the outbreak, novel aspects and insights concerning the unprecedented response, scientific observations, and public health implications. The large number of Ebola survivors has highlighted the frequency of persistent symptoms and the possibility of virus persistence in sanctuary sites, sometimes leading to delayed transmission. Although transmission appears to have ceased in 2016, the West Africa Ebola epidemic has profoundly influenced discussions and practice concerning global health security. Expected final online publication date for the Annual Review of Medicine Volume 68 is January 14, 2017. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates. |
Resurgence of Ebola virus disease in Guinea linked to a survivor with virus persistence in seminal fluid for more than 500 days
Diallo B , Sissoko D , Loman NJ , Bah HA , Bah H , Worrell MC , Conde LS , Sacko R , Mesfin S , Loua A , Kalonda JK , Erondu NA , Dahl BA , Handrick S , Goodfellow I , Meredith LW , Cotten M , Jah U , Guetiya Wadoum RE , Rollin P , Magassouba N , Malvy D , Anglaret X , Carroll MW , Aylward RB , Djingarey MH , Diarra A , Formenty P , Keita S , Gunther S , Rambaut A , Duraffour S . Clin Infect Dis 2016 63 (10) 1353-1356 We report on an Ebola virus disease (EVD) survivor who showed Ebola virus (EBOV) in seminal fluid 531 days after onset of disease. The persisting virus was sexually transmitted in February 2016, about 470 days after onset of symptoms, and caused a new cluster of EVD in Guinea and Liberia. |
Ebola surveillance - Guinea, Liberia, and Sierra Leone
McNamara LA , Schafer IJ , Nolen LD , Gorina Y , Redd JT , Lo T , Ervin E , Henao O , Dahl BA , Morgan O , Hersey S , Knust B . MMWR Suppl 2016 65 (3) 35-43 Developing a surveillance system during a public health emergency is always challenging but is especially so in countries with limited public health infrastructure. Surveillance for Ebola virus disease (Ebola) in the West African countries heavily affected by Ebola (Guinea, Liberia, and Sierra Leone) faced numerous impediments, including insufficient numbers of trained staff, community reticence to report cases and contacts, limited information technology resources, limited telephone and Internet service, and overwhelming numbers of infected persons. Through the work of CDC and numerous partners, including the countries' ministries of health, the World Health Organization, and other government and nongovernment organizations, functional Ebola surveillance was established and maintained in these countries. CDC staff were heavily involved in implementing case-based surveillance systems, sustaining case surveillance and contact tracing, and interpreting surveillance data. In addition to helping the ministries of health and other partners understand and manage the epidemic, CDC's activities strengthened epidemiologic and data management capacity to improve routine surveillance in the countries affected, even after the Ebola epidemic ended, and enhanced local capacity to respond quickly to future public health emergencies. However, the many obstacles overcome during development of these Ebola surveillance systems highlight the need to have strong public health, surveillance, and information technology infrastructure in place before a public health emergency occurs. Intense, long-term focus on strengthening public health surveillance systems in developing countries, as described in the Global Health Security Agenda, is needed.The activities summarized in this report would not have been possible without collaboration with many U.S and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html). |
CDC's response to the 2014-2016 Ebola epidemic - Guinea, Liberia, and Sierra Leone
Dahl BA , Kinzer MH , Raghunathan PL , Christie A , De Cock KM , Mahoney F , Bennett SD , Hersey S , Morgan OW . MMWR Suppl 2016 65 (3) 12-20 CDC's response to the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa was the largest in the agency's history and occurred in a geographic area where CDC had little operational presence. Approximately 1,450 CDC responders were deployed to Guinea, Liberia, and Sierra Leone since the start of the response in July 2014 to the end of the response at the end of March 2016, including 455 persons with repeat deployments. The responses undertaken in each country shared some similarities but also required unique strategies specific to individual country needs. The size and duration of the response challenged CDC in several ways, particularly with regard to staffing. The lessons learned from this epidemic will strengthen CDC's ability to respond to future public health emergencies. These lessons include the importance of ongoing partnerships with ministries of health in resource-limited countries and regions, a cadre of trained CDC staff who are ready to be deployed, and development of ongoing working relationships with U.S. government agencies and other multilateral and nongovernment organizations that deploy for international public health emergencies. CDC's establishment of a Global Rapid Response Team in June 2015 is anticipated to meet some of these challenges. The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html). |
Genotypes of rubella virus and the epidemiology of rubella infections in the Democratic Republic of the Congo, 2004-2013.
Pukuta E , Waku-Kouomou D , Abernathy E , Illunga BK , Obama R , Mondonge V , Dahl BA , Maresha BG , Icenogle J , Muyembe JJ . J Med Virol 2016 88 (10) 1677-84 ![]() Rubella is a viral infection that may cause fetal death or congenital defects, known as congenital rubella syndrome (CRS), during early pregnancy. The World Health Organization (WHO) recommends that countries assess the burden of rubella and CRS, including the determination of genotypes of circulating viruses. The goal of this study was to identify the genotypes of rubella viruses in the Democratic Republic of the Congo (DRC). Serum or throat swab samples were collected through the measles surveillance system. Sera that tested negative for measles IgM antibody were tested for rubella IgM antibody. Serum collected within 4 days of rash onset and throat swabs were screened by real-time RT-PCR for rubella virus RNA. For positive samples, an amplicon of the E1 glycoprotein gene was amplified by RT-PCR and sequenced. 11733 sera were tested for rubella IgM and 2816 (24%) were positive; 145 (5%) were tested for the presence of rubella RNA by real-time RT-PCR and 10 (7%) were positive. Seventeen throat swabs were analyzed by RT-PCR and three were positive. Sequences were obtained from eight of the positive samples. Phylogenetic analysis showed that the DRC rubella viruses belonged to genotypes 1B, 1E, 1G, and 2B. This report provides the first information on the genotypes of rubella virus circulating in the DRC. These data contribute to a better understanding of rubella burden and the dynamics of rubella virus circulation in Africa. Efforts to establish rubella surveillance in the DRC are needed to support rubella elimination in Africa. J. Med. Virol. © 2016 Wiley Periodicals, Inc. |
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. |
Epidemiology of epidemic ebola virus disease in Conakry and surrounding prefectures, Guinea, 2014-2015
Rico A , Brody D , Coronado F , Rondy M , Fiebig L , Carcelen A , Deyde VM , Mesfin S , Retzer KD , Bilivogui P , Keita S , Dahl BA . Emerg Infect Dis 2016 22 (2) 178-83 In 2014, Ebola virus disease (EVD) in West Africa was first reported during March in 3 southeastern prefectures in Guinea; from there, the disease rapidly spread across West Africa. We describe the epidemiology of EVD cases reported in Guinea's capital, Conakry, and 4 surrounding prefectures (Coyah, Dubreka, Forecariah, and Kindia), encompassing a full year of the epidemic. A total of 1,355 EVD cases, representing approximately 40% of cases reported in Guinea, originated from these areas. Overall, Forecariah had the highest cumulative incidence (4x higher than that in Conakry). Case-fatality percentage ranged from 40% in Conakry to 60% in Kindia. Cumulative incidence was slightly higher among male than female residents, although incidences by prefecture and commune differed by sex. Over the course of the year, Conakry and neighboring prefectures became the EVD epicenter in Guinea. |
Strengthening laboratory capacity through the surveillance of rotavirus gastroenteritis in Central Africa: the Surveillance Epidemiologique en Afrique Centrale (SURVAC) Project
Waku-Kouomou D , Esona MD , Pukuta E , Gouandijka-Vasilache I , Boula A , Dahl BA , Mondonge V , Mekontso D , Guifara G , Mbary-Daba R , Lewis J , Yahaya AA , Mwenda JM , Cavallaro KF , Gody JC , Muyembe JJ , Ndombo PK , Bowen MD . Trop Med Int Health 2015 21 (1) 122-130 OBJECTIVES: The goal of the SURVAC pilot project was to strengthen disease surveillance and response in three countries; Cameroon (CAE), Democratic Republic of the Congo (DRC) and Central African Republic (CAR). METHODS: Seven laboratories involved in rotavirus surveillance were provided with equipment, reagents and supplies. CDC and WHO staff provided on-site classroom and bench training in biosafety, quality assurance, quality control (QC), rotavirus diagnosis using Enzyme Immunoassay (EIA), and genotyping of rotavirus strains using the Reverse-Transcription Polymerase chain reaction (RT-PCR). All laboratory data were reported through WHO/AFRO. RESULTS: 23 staff members were trained on RT-PCR for rotavirus genotyping which was introduced for the first time in all three countries. In CAE, the number of samples analyzed by EIA and RT-PCR increased tenfold between 2007 and 2013. In DRC, this number increased fivefold, from 2009 to 2013 whereas in CAR, it increased fourfold between 2011 and 2013. All laboratories passed WHO proficiency testing in 2014. CONCLUSION: Laboratory capacity was strengthened through equipping laboratories and strengthening a sub-regional laboratory workforce for surveillance of rotavirus gastroenteritis. Each of the three countries generated rotavirus surveillance and genotyping data enabling the mapping of circulating genotypes. These results will help monitor the impact of rotavirus vaccination in these countries. |
Ebola transmission linked to a single traditional funeral ceremony - Kissidougou, Guinea, December, 2014-January 2015
Victory KR , Coronado F , Ifono SO , Soropogui T , Dahl BA . MMWR Morb Mortal Wkly Rep 2015 64 (14) 386-388 On December 18, 2014, the Guinea Ministry of Health was notified by local public health authorities in Kissidougou, a prefecture in southeastern Guinea (pop. 284,000), that the number of cases of Ebola virus disease (Ebola) had increased from one case reported during December 8-14, 2014, to 62 cases reported during December 15-21. Kissidougou is one of the four Guinea prefectures (the others are Macenta, Gueckedou, and Conakry) where Ebola was first reported in West Africa in March 2014, and the mid-December increase was the largest documented by any prefecture in Guinea in a single week since the beginning of the epidemic. The Guinea Ministry of Health requested assistance from CDC and the World Health Organization to investigate the local outbreak, identify and isolate persons with suspected Ebola, assess transmission chains, and implement control measures. The investigation found that 85 confirmed Ebola cases were linked to one traditional funeral ceremony, including 62 (73%) cases reported during December 15-21. No additional cases related to this funeral ceremony were reported after January 10, 2015. After the outbreak was identified, rapid implementation of interventions limited additional Ebola virus transmission. Improved training for prompt reporting of cases, investigation, and contact tracing, and community acceptance of safe burial methods can reduce the risk for Ebola transmission in rural communities. |
Molecular surveillance of rotavirus strains circulating in Yaoundé, Cameroon, September 2007-December 2012.
Boula A , Waku-Kouomou D , Kinkela MN , Esona MD , Kemajou G , Mekontso D , Seheri M , Ndze VN , Emah I , Ela S , Dahl BA , Kobela M , Cavallaro KF , Mballa GA , Genstch JR , Bowen MD , Ndombo PK . Infect Genet Evol 2014 28 470-5 ![]() Rotavirus is the most common cause of severe diarrheal disease in children under 5 years of age worldwide. The World Health Organization (WHO) estimated that 453,000 rotavirus-attributable deaths occur annually. Through the WHO, the Rotavirus Sentinel Surveillance Program was established in Cameroon in September 2007 with the Mother and Child Center (MCC) in Yaounde playing the role of sentinel site and national laboratory for this program. The objectives of this surveillance were to assess the rotavirus disease burden and collect baseline information on rotavirus strains circulating in Cameroon. Diarrheal stool samples were collected in a pediatric hospital from children under 5, using the WHO case definition for rotavirus diarrhea. Antigen detection of rotavirus was performed by using an enzyme immunoassay (EIA). The genotypic characterization was performed using multiplexed semi-nested reverse transcription-polymerase chain reaction (RT-PCR) assays. Between September 2007 and December 2012, 2444 stool samples were received at the MCC laboratory for rotavirus antigen detection, of which 999 (41%) were EIA positive. Among EIA positive samples 898 were genotyped. Genotype prevalence varied each year. Genotype G9P[8] was the dominant type during 2007 (32%) and 2008 (24%), genotype G3P[6] predominated in 2010 (36%) and 2011 (25%), and G1P[8] was predominant in 2012 (44%). The findings showed that the rotavirus disease burden is high and there is a broad range of rotavirus strains circulating in Yaounde. These data will help measure the impact of vaccination in the future. |
Molecular surveillance of rotavirus infection in Bangui, Central African Republic, October 2011-September 2013.
Banga-Mingo V , Waku-Kouomou D , Gody JC , Esona MD , Yetimbi JF , Mbary-Daba R , Dahl BA , Dimanche L , Koyazegbe TD , Tricou V , Cavallaro KF , Guifara G , Bowen MD , Gouandjika-Vasilache I . Infect Genet Evol 2014 28 476-9 ![]() BACKGROUND: The World Health Organization (WHO) recommends the introduction of rotavirus vaccine in the immunization program of all countries. In the Central African Republic (CAR), sentinel surveillance for rotavirus gastroenteritis was established in 2011 by the Ministry of Health, with the support of the Surveillance en Afrique Centrale Project (SURVAC). The purpose of this study was to assess the burden of rotavirus gastroenteritis and to identify rotavirus strains circulating in CAR before the introduction of rotavirus vaccine planned for this year, 2014. METHODS: One sentinel site and one laboratory at the national level were designated by the CAR Ministry of Health to participate in this surveillance system. Stool samples were collected from children who met the WHO rotavirus gastroenteritis case definition (WHO, 2006). The samples were first screened for group A rotavirus antigen by enzyme immunoassay (EIA), and genotyping assays performed using a multiplex reverse transcriptase PCR (RT-PCR) technique. RESULTS: Between October 2011 and September 2013, 438 stool samples were collected and analyzed for detection of rotavirus antigen; 206 (47%) were positive. Among the 160 (78%) that could be genotyped, G2P[6] was the predominant strain (47%) followed by G1P[8] (25%) and G2P[4] (13%). CONCLUSIONS: Almost half of stool samples obtained from children hospitalized with gastroenteritis were positive for rotavirus. These baseline rotavirus surveillance data will be useful to health authorities considering rotavirus vaccine introduction and for evaluating the efficacy of rotavirus vaccine once it is introduced into the routine immunization system. |
Molecular surveillance of rotavirus infection in the Democratic Republic of the Congo August 2009 to June 2012.
Pukuta ES , Esona MD , Nkongolo A , Seheri M , Makasi M , Nyembwe M , Mondonge V , Dahl BA , Mphahlele MJ , Cavallaro K , Gentsch J , Bowen MD , Waku-Kouomou D , Muyembe JJ . Pediatr Infect Dis J 2014 33 (4) 355-9 ![]() BACKGROUND: Rotavirus is a major cause of severe diarrhea worldwide. It causes 453,000 deaths in children annually. In the Democratic Republic of the Congo, sentinel site surveillance of rotavirus gastroenteritis started in 2009 and aimed to document burden of rotavirus diarrhea and identify circulating rotavirus genotypes. METHODS: Between August 2009 to June 2012, stool samples were collected in Kinshasa and Lubumbashi, from children <5 years of age who met the WHO case definition for rotavirus gastroenteritis. Rotavirus antigen detection was performed using an enzyme immunoassay technique and rotavirus strains were characterized using a multiplex reverse transcription polymerase chain reaction assay. RESULTS: During the study period, 1614 stool samples were screened for rotavirus by enzyme immunoassay and 990 (61%) were positive. Of these, the genotype was determined in 330 (33%) samples. The most common genotypes found in the samples analyzed were G1P[8] in 2009 (28%) and 2012 (33%), G2P[4] (33%) in 2010 and G2P[6] (28%) in 2011. Uncommon strains like G8P[6] (5%), G6P[6] (5%), G12P[6] (3%), G12P[8] (3%) and G8P[8] (2%) were also detected. CONCLUSIONS: In Democratic Republic of the Congo, 61% of the diarrhea in children in <5 years of age was caused by rotavirus infection and a variety of rotavirus genotypes were detected. Implementation of rotavirus genotyping at the national level has improved the timely identification of rotavirus strains. These results will help decision makers in Democratic Republic of the Congo plan the implementation of a rotavirus vaccination program. |
Evaluation of antibacterial soap in the management of lymphoedema in Leogane, Haiti
Addiss DG , Michel MC , Michelus A , Radday J , Billhimer W , Louis-Charles J , Roberts JM , Kramp K , Dahl BA , Keswick B . Trans R Soc Trop Med Hyg 2010 105 (1) 58-60 In areas endemic for lymphatic filariasis, progression of lymphoedema is associated with recurrent bacterial acute dermatolymphangioadenitis (ADLA). The role of antibacterial soap in preventing ADLA is unknown. In a randomized double-blinded clinical trial in Leogane, Haiti, lymphoedema patients washed affected legs with antibacterial (n=97) or plain soap (n=100). Reported ADLA incidence (by recall) before the study was 1.1 episodes per person-year, compared to 0.40 assessed during the 12-month study. ADLA incidence was significantly associated with age, illiteracy and lymphoedema stage, but not with soap type. Washing with soap, regardless of its antibacterial content, can help decrease ADLA incidence. (ClinicalTrials.gov identifier number NCT00139100.). |
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