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1.
J Infect Dis ; 219(10): 1634-1641, 2019 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-30561672

RESUMEN

OBJECTIVE: In November 2015, a 15-year-old boy received a diagnosis of Ebola virus disease (EVD) at the John F. Kennedy Medical Center in Monrovia, Liberia. Two additional family members received a diagnosis of EVD. The protocol for a phase 2 placebo-controlled trial of 2 Ebola vaccines was amended and approved; in 4 days, a single-arm cluster vaccination trial using the Merck rVSVΔG-ZEBOV-GP vaccine was initiated. Here, we evaluate the safety and immunogenicity of the vaccine and discuss challenges for its implementation in a small Ebola outbreak. METHOD: We conducted a ring vaccination study among contacts and contacts of close contacts of EVD cases a in Monrovia. Participants were evaluated 1 and 6 months after vaccination. RESULTS: Among 650 close contacts and contacts of close contacts of EVD cases, 210 (32%) consented and were vaccinated with rVSVΔG-ZEBOV-GP. Of those vaccinated, 189 (90%) attended the month 1 follow-up visit; 166 (79%) attended the month 6 visit. No serious adverse events were reported. Among 88 participants without an elevated antibody level at baseline, 77.3% (95% confidence interval, 68.5-86.1) had an antibody response at 1 month. CONCLUSIONS: The Merck rVSVΔG-ZEBOV-GP vaccine appeared to be safe and immunogenic among the vaccinated individuals. However, fewer than one third of eligible individuals consented to vaccination. These data may help guide implementation decisions for of cluster vaccination programs in an Ebola cluster outbreak response situation.


Asunto(s)
Vacunas contra el Virus del Ébola/administración & dosificación , Fiebre Hemorrágica Ebola/prevención & control , Vacunación/estadística & datos numéricos , Adolescente , Adulto , Anciano , Trazado de Contacto , Brotes de Enfermedades/prevención & control , Vacunas contra el Virus del Ébola/efectos adversos , Vacunas contra el Virus del Ébola/inmunología , Ebolavirus/inmunología , Femenino , Fiebre Hemorrágica Ebola/inmunología , Humanos , Liberia , Masculino , Persona de Mediana Edad
2.
Emerg Infect Dis ; 24(8): 1551-1554, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30016245

RESUMEN

We examined human stool samples from Liberia for soil-transmitted helminth ova by Kato-Katz smear and by quantitative PCR. Twenty-five samples were positive for Trichuris trichiura by smear but negative by quantitative PCR. Reexamination of samples showed that they contained Capillaria eggs that resemble T. trichiura in Kato-Katz smears.


Asunto(s)
Ascariasis/diagnóstico , Capillaria/aislamiento & purificación , Infecciones por Enoplida/diagnóstico , Esquistosomiasis mansoni/diagnóstico , Tricuriasis/diagnóstico , Trichuris/aislamiento & purificación , Adolescente , Adulto , Animales , Ascariasis/epidemiología , Ascariasis/parasitología , Ascaris lumbricoides/anatomía & histología , Ascaris lumbricoides/clasificación , Ascaris lumbricoides/genética , Ascaris lumbricoides/aislamiento & purificación , Capillaria/anatomía & histología , Capillaria/clasificación , Capillaria/genética , Niño , Diagnóstico Diferencial , Infecciones por Enoplida/epidemiología , Infecciones por Enoplida/parasitología , Heces/parasitología , Femenino , Humanos , Liberia/epidemiología , Masculino , Persona de Mediana Edad , Recuento de Huevos de Parásitos , Reacción en Cadena en Tiempo Real de la Polimerasa , Schistosoma mansoni/anatomía & histología , Schistosoma mansoni/clasificación , Schistosoma mansoni/genética , Schistosoma mansoni/aislamiento & purificación , Esquistosomiasis mansoni/epidemiología , Esquistosomiasis mansoni/parasitología , Tricuriasis/epidemiología , Tricuriasis/parasitología , Trichuris/anatomía & histología , Trichuris/clasificación , Trichuris/genética
3.
J Infect Dis ; 214(suppl 3): S222-S228, 2016 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-27443616

RESUMEN

BACKGROUND: Lateral flow immunoassays (LFIs) are point-of-care diagnostic assays that are designed for single use outside a formal laboratory, with in-home pregnancy tests the best-known example of these tests. Although the LFI has some limitations over more-complex immunoassay procedures, such as reduced sensitivity and the potential for false-positive results when using complex sample matrices, the assay has the benefits of a rapid time to result and ease of use. These benefits make it an attractive option for obtaining rapid results in an austere environment. In an outbreak of any magnitude, a field-based rapid diagnostic assay would allow proper patient transport and for safe burials to be conducted without the delay caused by transport of samples between remote villages and testing facilities. Use of such point-of-care instruments in the ongoing Ebola virus disease (EVD) outbreak in West Africa would have distinct advantages in control and prevention of local outbreaks, but proper understanding of the technology and interpretation of results are important. METHODS: In this study, a LFI, originally developed by the Naval Medical Research Center for Ebola virus environmental testing, was evaluated for its ability to detect the virus in clinical samples in Liberia. Clinical blood and plasma samples and post mortem oral swabs submitted to the Liberian Institute for Biomedical Research, the National Public Health Reference Laboratory for EVD testing, were tested and compared to results of real-time reverse transcription-polymerase chain reaction (rRT-PCR), using assays targeting Ebola virus glycoprotein and nucleoprotein. RESULTS: The LFI findings correlated well with those of the real-time RT-PCR assays used as benchmarks. CONCLUSIONS: Rapid antigen-detection tests such as LFIs are attractive alternatives to traditional immunoassays but have reduced sensitivity and specificity, resulting in increases in false-positive and false-negative results. An understanding of the strengths, weaknesses, and limitations of a particular assay lets the diagnostician choose the correct situation to use the correct assay and properly interpret the results.


Asunto(s)
Brotes de Enfermedades , Ebolavirus/inmunología , Fiebre Hemorrágica Ebola/diagnóstico , Inmunoensayo/métodos , Sistemas de Atención de Punto , Ebolavirus/aislamiento & purificación , Glicoproteínas/inmunología , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/virología , Humanos , Liberia/epidemiología , Nucleoproteínas/inmunología , Salud Pública , Reacción en Cadena en Tiempo Real de la Polimerasa , Sensibilidad y Especificidad
4.
J Infect Dis ; 214(suppl 3): S303-S307, 2016 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-27471319

RESUMEN

The development of point-of-care clinical chemistry analyzers has enabled the implementation of these ancillary tests in field laboratories in resource-limited outbreak areas. The Eternal Love Winning Africa (ELWA) outbreak diagnostic laboratory, established in Monrovia, Liberia, to provide Ebola virus and Plasmodium spp. diagnostics during the Ebola epidemic, implemented clinical chemistry analyzers in December 2014. Clinical chemistry testing was performed for 68 patients in triage, including 12 patients infected with Ebola virus and 18 infected with Plasmodium spp. The main distinguishing feature in clinical chemistry of Ebola virus-infected patients was the elevation in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and γ-glutamyltransferase levels and the decrease in calcium. The implementation of clinical chemistry is probably most helpful when the medical supportive care implemented at the Ebola treatment unit allows for correction of biochemistry derangements and on-site clinical chemistry analyzers can be used to monitor electrolyte balance.


Asunto(s)
Brotes de Enfermedades , Epidemias , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/epidemiología , Malaria/diagnóstico , Adolescente , Alanina Transaminasa/análisis , Fosfatasa Alcalina/análisis , Aspartato Aminotransferasas/análisis , Química Clínica , Servicios de Laboratorio Clínico , Ebolavirus/inmunología , Ebolavirus/aislamiento & purificación , Fiebre Hemorrágica Ebola/virología , Humanos , Liberia/epidemiología , Pruebas de Función Hepática , Malaria/epidemiología , Malaria/parasitología , Masculino , Plasmodium/aislamiento & purificación , Plasmodium/metabolismo , Sistemas de Atención de Punto , gamma-Glutamiltransferasa/análisis
5.
J Infect Dis ; 214(suppl 3): S169-S176, 2016 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-27333914

RESUMEN

West Africa experienced the first epidemic of Ebola virus infection, with by far the greatest number of cases in Guinea, Sierra Leone, and Liberia. The unprecedented epidemic triggered an unparalleled response, including the deployment of multiple Ebola treatment units and mobile/field diagnostic laboratories. The National Institute of Allergy and Infectious Diseases and the Centers for Disease Control and Prevention deployed a joint laboratory to Monrovia, Liberia, in August 2014 to support the newly founded Ebola treatment unit at the Eternal Love Winning Africa (ELWA) campus. The laboratory operated initially out of a tent structure but quickly moved into a fixed-wall building owing to severe weather conditions, the need for increased security, and the high sample volume. Until May 2015, when the laboratory closed, the site handled close to 6000 clinical specimens for Ebola virus diagnosis and supported the medical staff in case patient management. Laboratory operation and safety, as well as Ebola virus diagnostic assays, are described and discussed; in addition, lessons learned for future deployments are reviewed.


Asunto(s)
Servicios de Laboratorio Clínico/organización & administración , Ebolavirus/aislamiento & purificación , Epidemias/prevención & control , Fiebre Hemorrágica Ebola/epidemiología , África Occidental/epidemiología , Centers for Disease Control and Prevention, U.S. , Femenino , Guinea/epidemiología , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/transmisión , Fiebre Hemorrágica Ebola/virología , Humanos , Cooperación Internacional , Liberia/epidemiología , Masculino , National Institute of Allergy and Infectious Diseases (U.S.) , Seguridad , Sierra Leona/epidemiología , Estados Unidos
6.
Clin Infect Dis ; 63(8): 1026-33, 2016 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-27531847

RESUMEN

BACKGROUND: The ongoing Ebola outbreak in West Africa has resulted in 28 646 suspected, probable, and confirmed Ebola virus infections. Nevertheless, malaria remains a large public health burden in the region affected by the outbreak. A joint Centers for Disease Control and Prevention/National Institutes of Health diagnostic laboratory was established in Monrovia, Liberia, in August 2014, to provide laboratory diagnostics for Ebola virus. METHODS: All blood samples from suspected Ebola virus-infected patients admitted to the Médecins Sans Frontières ELWA3 Ebola treatment unit in Monrovia were tested by quantitative real-time polymerase chain reaction for the presence of Ebola virus and Plasmodium species RNA. Clinical outcome in laboratory-confirmed Ebola virus-infected patients was analyzed as a function of age, sex, Ebola viremia, and Plasmodium species parasitemia. RESULTS: The case fatality rate of 1182 patients with laboratory-confirmed Ebola virus infections was 52%. The probability of surviving decreased with increasing age and decreased with increasing Ebola viral load. Ebola virus-infected patients were 20% more likely to survive when Plasmodium species parasitemia was detected, even after controlling for Ebola viral load and age; those with the highest levels of parasitemia had a survival rate of 83%. This effect was independent of treatment with antimalarials, as this was provided to all patients. Moreover, treatment with antimalarials did not affect survival in the Ebola virus mouse model. CONCLUSIONS: Plasmodium species parasitemia is associated with an increase in the probability of surviving Ebola virus infection. More research is needed to understand the molecular mechanism underlying this remarkable phenomenon and translate it into treatment options for Ebola virus infection.


Asunto(s)
Coinfección , Ebolavirus , Fiebre Hemorrágica Ebola/complicaciones , Fiebre Hemorrágica Ebola/mortalidad , Malaria/complicaciones , Malaria/parasitología , Parasitemia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Niño , Preescolar , Modelos Animales de Enfermedad , Ebolavirus/genética , Femenino , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Lactante , Recién Nacido , Malaria/diagnóstico , Malaria/epidemiología , Masculino , Ratones , Persona de Mediana Edad , Carga de Parásitos , Plasmodium/genética , Tasa de Supervivencia , Carga Viral , Adulto Joven
7.
Emerg Infect Dis ; 22(2): 331-4, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26812583

RESUMEN

Rapid sequencing of RNA/DNA from pathogen samples obtained during disease outbreaks provides critical scientific and public health information. However, challenges exist for exporting samples to laboratories or establishing conventional sequencers in remote outbreak regions. We successfully used a novel, pocket-sized nanopore sequencer at a field diagnostic laboratory in Liberia during the current Ebola virus outbreak.


Asunto(s)
Ebolavirus/genética , Fiebre Hemorrágica Ebola/microbiología , Nanoporos , Análisis de Secuencia de ADN/métodos , Brotes de Enfermedades , Genoma Viral , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Mutación
8.
Emerg Infect Dis ; 22(2): 323-6, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26814608

RESUMEN

Malaria is a major public health concern in the countries affected by the Ebola virus disease epidemic in West Africa. We determined the feasibility of using molecular malaria diagnostics during an Ebola virus disease outbreak and report the incidence of Plasmodium spp. parasitemia in persons with suspected Ebola virus infection.


Asunto(s)
Coinfección , Brotes de Enfermedades , Ebolavirus , Fiebre Hemorrágica Ebola/epidemiología , Malaria/diagnóstico , Malaria/parasitología , Humanos , Malaria Falciparum/diagnóstico , Malaria Falciparum/parasitología , Carga de Parásitos , Plasmodium falciparum/clasificación , Plasmodium falciparum/genética , Prevalencia
9.
Emerg Infect Dis ; 21(7): 1135-43, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26079255

RESUMEN

To support Liberia's response to the ongoing Ebola virus (EBOV) disease epidemic in Western Africa, we established in-country advanced genomic capabilities to monitor EBOV evolution. Twenty-five EBOV genomes were sequenced at the Liberian Institute for Biomedical Research, which provided an in-depth view of EBOV diversity in Liberia during September 2014-February 2015. These sequences were consistent with a single virus introduction to Liberia; however, shared ancestry with isolates from Mali indicated at least 1 additional instance of movement into or out of Liberia. The pace of change is generally consistent with previous estimates of mutation rate. We observed 23 nonsynonymous mutations and 1 nonsense mutation. Six of these changes are within known binding sites for sequence-based EBOV medical countermeasures; however, the diagnostic and therapeutic impact of EBOV evolution within Liberia appears to be low.


Asunto(s)
Ebolavirus/genética , Fiebre Hemorrágica Ebola/virología , Antivirales/farmacología , Antivirales/uso terapéutico , Análisis Mutacional de ADN , Farmacorresistencia Viral/genética , Evolución Molecular , Genes Virales , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Liberia/epidemiología
10.
Malar J ; 13: 417, 2014 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-25363349

RESUMEN

BACKGROUND: Mass drug administration (MDA) of ivermectin to humans for control and elimination of filarial parasites can kill biting malaria vectors and lead to Plasmodium transmission reduction. This study examines the degree and duration of mosquitocidal effects resulting from single MDAs conducted in three different West African countries, and the subsequent reductions in parity and Plasmodium sporozoite rates. METHODS: Indoor-resting, blood-fed and outdoor host-seeking Anopheles spp. were captured on days surrounding MDAs from 2008-2013 in Senegalese, Liberian and Burkinabé villages. Mortality was assessed on a portion of the indoor collection, and parity status was determined on host-seeking mosquitoes. The effect of MDA was then analysed against the time relative to the MDA, the distributed drugs and environmental variables. RESULTS: Anopheles gambiae survivorship was reduced by 33.9% for one week following MDA and parity rates were significantly reduced for more than two weeks after the MDAs. Sporozoite rates were significantly reduced by >77% for two weeks following the MDAs in treatment villages despite occurring in the middle of intense transmission seasons. These observed effects were consistent across three different West African transmission dynamics. CONCLUSIONS: These data provide a comprehensive and crucial evidence base for the significant reduction in malaria transmission following single ivermectin MDAs across diverse field sites. Despite the limited duration of transmission reduction, these results support the hypothesis that repeated MDAs with optimal timing could help sustainably control malaria as well as filarial transmission.


Asunto(s)
Anopheles/efectos de los fármacos , Antimaláricos/administración & dosificación , Insecticidas/administración & dosificación , Ivermectina/administración & dosificación , Malaria/prevención & control , África Occidental , Animales , Anopheles/fisiología , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Femenino , Humanos , Insecticidas/farmacología , Insecticidas/uso terapéutico , Ivermectina/farmacología , Ivermectina/uso terapéutico , Malaria/tratamiento farmacológico , Malaria/transmisión , Paridad/efectos de los fármacos , Plasmodium/efectos de los fármacos , Esporozoítos/efectos de los fármacos
11.
PLoS Negl Trop Dis ; 16(1): e0010083, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-35085236

RESUMEN

The West African Ebola Virus Disease epidemic of 2014-16 cost more than 11,000 lives. Interventions targeting key behaviors to curb transmission, such as safe funeral practices and reporting and isolating the ill, were initially unsuccessful in a climate of fear, mistrust, and denial. Building trust was eventually recognized as essential to epidemic response and prioritized, and trust was seen to improve toward the end of the epidemic as incidence fell. However, little is understood about how and why trust changed during Ebola, what factors were most influential to community trust, and how different institutions might have been perceived under different levels of exposure to the outbreak. In this large-N household survey conducted in Liberia in 2018, we measured self-reported trust over time retrospectively in three different communities with different exposures to Ebola. We found trust was consistently higher for non-governmental organizations than for the government of Liberia across all time periods. Trust reportedly decreased significantly from the start to the peak of the epidemic in the study site of highest Ebola incidence. This finding, in combination with a negative association found between knowing someone infected and trust of both iNGOs and the government, indicates the experience of Ebola may have itself caused a decline of trust in the community. These results suggest that national governments should aim to establish trust when engaging communities to change behavior during epidemics. Further research on the relationship between trust and epidemics may serve to improve epidemic response efficacy and behavior uptake.


Asunto(s)
Epidemias/psicología , Fiebre Hemorrágica Ebola/psicología , Confianza/psicología , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Gobierno , Conocimientos, Actitudes y Práctica en Salud , Fiebre Hemorrágica Ebola/prevención & control , Humanos , Incidencia , Liberia , Masculino , Persona de Mediana Edad , Organizaciones , Estudios Retrospectivos , Encuestas y Cuestionarios
12.
Acta Trop ; 231: 106437, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35405102

RESUMEN

We assessed the impact of three annual vs five semiannual rounds of mass drug administration (MDA) with ivermectin plus albendazole followed by praziquantel for the control or elimination of lymphatic filariasis (LF), onchocerciasis, soil-transmitted helminth (STH) infections and schistosomiasis in Lofa County, Liberia. The study started in 2012 and was interrupted in 2014 during the Ebola virus outbreak. Repeated cross-sectional surveys were conducted in individuals 5 years and older to measure infection markers. Wuchereria bancrofti antigenemia prevalences decreased from 12.5 to 1.2% (90% reduction) and from 13.6 to 4.2% (69% reduction) one year after three rounds of annual or five rounds of semiannual MDA, respectively. Mixed effects logistic regression models showed decreases in odds of antigenemia positivity were 91 and 74% at that time in the annual and semiannual treatment zones, respectively (p < 0.001). Semiannual MDA was slightly more effective for reducing Onchocerca volvulus microfiladermia prevalence and at follow-up 3 were 74% (from 14.4 to 3.7%) and 83% (from 23.6 to 4.5%) in the annual and semiannual treatment zones, respectively. Both treatment schedules had similar beneficial effects on hookworm prevalence. Thus, annual and semiannual MDA with ivermectin and albendazole had similar beneficial impacts on LF, onchocerciasis, and STH in this setting. In contrast, MDA with praziquantel had little impact on hyperendemic Schistosoma mansoni in the study area. Results from a long-term follow-up survey showed that improvements in infection parameters were sustained by routine annual MDA provided by the Liberian Ministry of Health after our study endpoint.


Asunto(s)
Filariasis Linfática , Helmintiasis , Oncocercosis , Albendazol/farmacología , Albendazol/uso terapéutico , Animales , Estudios Transversales , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/epidemiología , Helmintiasis/tratamiento farmacológico , Helmintiasis/epidemiología , Humanos , Ivermectina/farmacología , Ivermectina/uso terapéutico , Liberia/epidemiología , Administración Masiva de Medicamentos/métodos , Oncocercosis/tratamiento farmacológico , Oncocercosis/epidemiología , Praziquantel/farmacología , Praziquantel/uso terapéutico , Prevalencia , Suelo , Wuchereria bancrofti
13.
PLoS Negl Trop Dis ; 16(12): e0010953, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36508458

RESUMEN

BACKGROUND: Mass drug administration (MDA) is the main strategy towards lymphatic filariasis (LF) elimination. Progress is monitored by assessing microfilaraemia (Mf) or circulating filarial antigenaemia (CFA) prevalence, the latter being more practical for field surveys. The current criterion for stopping MDA requires <2% CFA prevalence in 6- to 7-year olds, but this criterion is not evidence-based. We used mathematical modelling to investigate the validity of different thresholds regarding testing method and age group for African MDA programmes using ivermectin plus albendazole. METHODOLGY/PRINCIPAL FINDINGS: We verified that our model captures observed patterns in Mf and CFA prevalence during annual MDA, assuming that CFA tests are positive if at least one adult worm is present. We then assessed how well elimination can be predicted from CFA prevalence in 6-7-year-old children or from Mf or CFA prevalence in the 5+ or 15+ population, and determined safe (>95% positive predictive value) thresholds for stopping MDA. The model captured trends in Mf and CFA prevalences reasonably well. Elimination cannot be predicted with sufficient certainty from CFA prevalence in 6-7-year olds. Resurgence may still occur if all children are antigen-negative, irrespective of the number tested. Mf-based criteria also show unfavourable results (PPV <95% or unpractically low threshold). CFA prevalences in the 5+ or 15+ population are the best predictors, and post-MDA threshold values for stopping MDA can be as high as 10% for 15+. These thresholds are robust for various alternative assumptions regarding baseline endemicity, biological parameters and sampling strategies. CONCLUSIONS/SIGNIFICANCE: For African areas with moderate to high pre-treatment Mf prevalence that have had 6 or more rounds of annual ivermectin/albendazole MDA with adequate coverage, we recommend to adopt a CFA threshold prevalence of 10% in adults (15+) for stopping MDA. This could be combined with Mf testing of CFA positives to ensure absence of a significant Mf reservoir for transmission.


Asunto(s)
Filariasis Linfática , Filaricidas , Animales , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/epidemiología , Filariasis Linfática/prevención & control , Albendazol/uso terapéutico , Ivermectina/uso terapéutico , Filaricidas/uso terapéutico , Wuchereria bancrofti , África/epidemiología , Prevalencia
14.
Am J Trop Med Hyg ; 106(2): 700-709, 2021 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-34814104

RESUMEN

We compared the impact of three rounds of annual and five rounds of semiannual mass drug administration (MDA) with albendazole plus ivermectin on helminthic infections in Liberia. Repeated annual cross-sectional community surveys were conducted between 2013 and 2019 in individuals of 5 years and older. Primary outcome was the change of infection prevalence estimates from baseline to month 36 (12 months after the last treatment). After three rounds of annual MDA, Wuchereria bancrofti circulating filarial antigen (CFA) and microfilaria (Mf) prevalence estimates decreased from 19.7% to 4.3% and from 8.6% to 0%, respectively; after semiannual MDA, CFA and Mf prevalences decreased from 37.8% to 16.8% and 17.9% to 1%, respectively. Mixed effects logistic regression models indicated that the odds of having Mf decreased by 97% (P < 0.001) at month 36 (similar odds for annual and semiannual MDA zones). A parallel analysis showed that the odds of CFA were reduced by 83% and 69% at 36 months in the annual and semiannual treatment zones, respectively (P < 0.001). Onchocerca volvulus Mf prevalence decreased slightly after multiple MDA rounds in both treatment zones. Reductions in hookworm and Trichuris trichiura prevalences and intensities were slightly greater in the annual treatment zone. Ascaris lumbricoides prevalence rates were relatively unchanged, although infection intensities decreased sharply throughout. Results show that annual and semiannual MDA were equally effective for reducing LF and soil-transmitted helminth infection parameters over a 3-year period, and reductions recorded at month 36 were sustained by routine annual MDA through month 72.


Asunto(s)
Albendazol/uso terapéutico , Helmintiasis/tratamiento farmacológico , Ivermectina/uso terapéutico , Administración Masiva de Medicamentos/estadística & datos numéricos , Administración Masiva de Medicamentos/normas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antígenos Helmínticos/inmunología , Niño , Preescolar , Estudios Transversales , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/epidemiología , Femenino , Helmintiasis/clasificación , Helmintiasis/epidemiología , Infecciones por Uncinaria/tratamiento farmacológico , Infecciones por Uncinaria/epidemiología , Humanos , Liberia/epidemiología , Masculino , Administración Masiva de Medicamentos/métodos , Persona de Mediana Edad , Prevalencia , Tricuriasis/tratamiento farmacológico , Tricuriasis/epidemiología , Adulto Joven
15.
Artículo en Inglés | MEDLINE | ID: mdl-34444337

RESUMEN

Hand hygiene is central to hospital infection control. During the 2014-2016 West Africa Ebola virus disease epidemic in Liberia, gaps in hand hygiene infrastructure and health worker training contributed to hospital-based Ebola transmission. Hand hygiene interventions were undertaken post-Ebola, but many improvements were not sustainable. This study characterizes barriers to, and facilitators of, hand hygiene in rural Liberian hospitals and evaluates readiness for sustainable, locally derived interventions to improve hand hygiene. Research enumerators collected data at all hospitals in Bong and Lofa counties, Liberia, in the period March-May 2020. Enumerators performed standardized spot checks of hand hygiene infrastructure and supplies, structured observations of hand hygiene behavior, and semi-structured key informant interviews for thematic analysis. During spot checks, hospital staff reported that handwashing container water was always available in 89% (n = 42) of hospital wards, piped running water in 23% (n = 11), and soap in 62% (n = 29). Enumerators observed 5% of wall-mounted hand sanitizer dispensers (n = 8) and 95% of pocket-size dispensers (n = 53) to be working. In interviews, hospital staff described willingness to purchase personal hand sanitizer dispensers when hospital-provided supplies were unavailable. Low-cost, sustainable interventions should address supply and infrastructure-related obstacles to hospital hand hygiene improvement.


Asunto(s)
Higiene de las Manos , Desinfectantes para las Manos , Desinfección de las Manos , Hospitales Rurales , Humanos , Liberia
16.
PLoS Negl Trop Dis ; 12(3): e0006348, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29561834

RESUMEN

BACKGROUND: Novel surveillance strategies are needed to detect the rapid and continuous emergence of infectious disease agents. Ideally, new sampling strategies should be simple to implement, technologically uncomplicated, and applicable to areas where emergence events are known to occur. To this end, xenosurveillance is a technique that makes use of blood collected by hematophagous arthropods to monitor and identify vertebrate pathogens. Mosquitoes are largely ubiquitous animals that often exist in sizable populations. As well, many domestic or peridomestic species of mosquitoes will preferentially take blood-meals from humans, making them a unique and largely untapped reservoir to collect human blood. METHODOLOGY/PRINCIPAL FINDINGS: We sought to take advantage of this phenomenon by systematically collecting blood-fed mosquitoes during a field trail in Northern Liberia to determine whether pathogen sequences from blood engorged mosquitoes accurately mirror those obtained directly from humans. Specifically, blood was collected from humans via finger-stick and by aspirating bloodfed mosquitoes from the inside of houses. Shotgun metagenomic sequencing of RNA and DNA derived from these specimens was performed to detect pathogen sequences. Samples obtained from xenosurveillance and from finger-stick blood collection produced a similar number and quality of reads aligning to two human viruses, GB virus C and hepatitis B virus. CONCLUSIONS/SIGNIFICANCE: This study represents the first systematic comparison between xenosurveillance and more traditional sampling methodologies, while also demonstrating the viability of xenosurveillance as a tool to sample human blood for circulating pathogens.


Asunto(s)
Culicidae/virología , Monitoreo Epidemiológico , Virosis/epidemiología , Virus/aislamiento & purificación , Animales , Hepacivirus/genética , Hepacivirus/patogenicidad , Hepatitis B/epidemiología , Hepatitis B/virología , Virus de la Hepatitis B/genética , Virus de la Hepatitis B/aislamiento & purificación , Virus de la Hepatitis B/patogenicidad , Hepatitis C/epidemiología , Hepatitis C/virología , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Liberia/epidemiología , Metagenómica , Mosquitos Vectores/virología , Muestreo , Virosis/virología , Virus/genética , Virus/patogenicidad
17.
Microbiome ; 6(1): 33, 2018 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-29486796

RESUMEN

BACKGROUND: The human intestine and its microbiota is the most common infection site for soil-transmitted helminths (STHs), which affect the well-being of ~ 1.5 billion people worldwide. The complex cross-kingdom interactions are not well understood. RESULTS: A cross-sectional analysis identified conserved microbial signatures positively or negatively associated with STH infections across Liberia and Indonesia, and longitudinal samples analysis from a double-blind randomized trial showed that the gut microbiota responds to deworming but does not transition closer to the uninfected state. The microbiomes of individuals able to self-clear the infection had more alike microbiome assemblages compared to individuals who remained infected. One bacterial taxon (Lachnospiracae) was negatively associated with infection in both countries, and 12 bacterial taxa were significantly associated with STH infection in both countries, including Olsenella (associated with reduced gut inflammation), which also significantly reduced in abundance following clearance of infection. Microbial community gene abundances were also affected by deworming. Functional categories identified as associated with STH infection included arachidonic acid metabolism; arachidonic acid is the precursor for pro-inflammatory leukotrienes that threaten helminth survival, and our findings suggest that some modulation of arachidonic acid activity in the STH-infected gut may occur through the increase of arachidonic acid metabolizing bacteria. CONCLUSIONS: For the first time, we identify specific members of the gut microbiome that discriminate between moderately/heavily STH-infected and non-infected states across very diverse geographical regions using two different statistical methods. We also identify microbiome-encoded biological functions associated with the STH infections, which are associated potentially with STH survival strategies, and changes in the host environment. These results provide a novel insight of the cross-kingdom interactions in the human gut ecosystem by unlocking the microbiome assemblages at taxonomic, genetic, and functional levels so that advances towards key mechanistic studies can be made.


Asunto(s)
Clostridiales/metabolismo , Microbioma Gastrointestinal/fisiología , Helmintiasis/parasitología , Helmintiasis/transmisión , Suelo/parasitología , Adolescente , Adulto , Animales , Ácido Araquidónico/metabolismo , Niño , Estudios Transversales , Método Doble Ciego , Heces/parasitología , Femenino , Helmintos/metabolismo , Humanos , Indonesia , Intestinos/microbiología , Intestinos/parasitología , Liberia , Masculino , ARN Ribosómico 16S/genética , Adulto Joven
18.
J Virol Methods ; 255: 84-90, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29481881

RESUMEN

As part of the scientific community's development of medical countermeasures against Ebola virus disease, optimization of standardized assays for product evaluation is paramount. The recent outbreak heightened awareness to the scarcity of available assays and limited information on performance and reproducibility. To evaluate the immunogenicity of vaccines entering Phase I-III trials and to identify survivors, two enzyme-linked immunosorbent assays, the Filovirus Animal Non-Clinical Group assay and the Alpha Diagnostics International assay, were evaluated for detection of immunoglobulin G against Ebola virus glycoprotein. We found that the Filovirus Animal Nonclinical Group assay produced a wider range of relative antibody concentrations, higher assay precision, larger relative accuracy range, and lower regional background. Additionally, to sufficiently power a vaccine trial, use of the Filovirus Animal Nonclinical Group assay would require one third the number of participants than the Alpha Diagnostics International assay. This reduction in needed study participants will require less money, fewer man hours, and much less time to evaluate vaccine immunogenicity.


Asunto(s)
Ebolavirus , Fiebre Hemorrágica Ebola/diagnóstico , Inmunoensayo , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Ebolavirus/inmunología , Ensayo de Inmunoadsorción Enzimática , Filoviridae/inmunología , Fiebre Hemorrágica Ebola/inmunología , Fiebre Hemorrágica Ebola/prevención & control , Fiebre Hemorrágica Ebola/virología , Humanos , Inmunoensayo/métodos , Pruebas Serológicas , Vacunas Virales/inmunología
19.
Afr J Lab Med ; 5(3): 508, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28879142

RESUMEN

Prior to the Ebola virus disease outbreak in Liberia, the laboratory system was duplicative, fragmented and minimally coordinated. The National Reference Laboratory was conceptualised to address the existing challenges by promoting the implementation of effective and sustainable laboratory services in Liberia. However, in a resource-limited environment such as Liberia, progress regarding the rebuilding of the health system can be relatively slow, while efforts to sustain the transient gains remain a key challenge for the Ministry of Health. In this paper, we describe the pre-Ebola virus disease laboratory system in Liberia and its prevailing efforts to address future emerging infectious diseases, as well as current Infectious diseases, all of which are exacerbated by poverty. We conclude that laboratory and diagnostic services in Liberia have encountered numerous challenges regarding its efforts to strengthen the healthcare delivery system. These challenges include limited trained human resource capacity, inadequate infrastructure, and a lack of coordination. As with most countries in sub-Saharan Africa, when comparing urban and rural settings, diagnostic and clinical services are generally skewed toward urban health facilities and private, faith-based health facilities. We recommend that structured policy be directed at these challenges for national institutions to develop guidelines to improve, strengthen and sustain diagnostic and curative laboratory services to effectively address current infectious diseases and prepare for future emerging and re-emerging infectious diseases.

20.
Afr J Lab Med ; 5(3): 509, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28879143

RESUMEN

The laboratory system in Liberia has generally been fragmented and uncoordinated. Accordingly, the country's Ministry of Health established the National Reference Laboratory to strengthen and sustain laboratory services. However, diagnostic testing services were often limited to clinical tests performed in health facilities, with the functionality of the National Reference Laboratory restricted to performing testing services for a limited number of epidemic-prone diseases. The lack of testing capacity in-country for Lassa fever and other haemorrhagic fevers affected the response of the country's health system during the onset of the Ebola virus disease (EVD) outbreak. Based on the experiences of the EVD outbreak, efforts were initiated to strengthen the laboratory system and infrastructure, enhance human resource capacity, and invest in diagnostic services and public health surveillance to inform admittance, treatment, and discharge decisions. In this article, we briefly describe the pre-EVD laboratory capability in Liberia, and extensively explore the post-EVD strengthening initiatives to enhance capacity, mobilise resources and coordinate disaster response with international partners to rebuild the laboratory infrastructure in the country. Now that the EVD outbreak has ended, additional initiatives are needed to revise the laboratory strategic and operational plan for post-EVD relevance, promote continual human resource capacity, institute accreditation and validation programmes, and coordinate the investment strategy to strengthen and sustain the preparedness of the laboratory sector to mitigate future emerging and re-emerging infectious diseases.

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