Результаты поиска

Yellow Fever Vaccination in an Individual with Confirmed Egg Protein Allergy: A Case Report.

BACKGROUND: Yellow fever vaccination is recommended for travelers visiting endemic regions in South America and Africa. The live-attenuated vaccine (Stamaril®, Sanofi Pasteur) is produced in embryonated chicken eggs and contains residual ovalbumin, posing a challenge for individuals with egg protein allergy. CASE PRESENTATION: We report the case of a 35-year-old male disaster relief worker with confirmed egg protein allergy and moderate sensitization but no history of anaphylaxis. Under normal circumstances, a statement confirming that vaccination is not possible would be sufficient for entry…

Safety and Immunogenicity of the Attenuated Yellow Fever Vaccine in Several Neotropical Primate Species.

BACKGROUND/OBJECTIVE: Yellow fever (YF) is an acute infectious disease caused by the yellow fever virus which is transmitted by mosquitoes. Neotropical primates are susceptible to infection, which is often presented as epizootic outbreaks. The aim was to evaluate and characterize the immune response against YF in different species of neotropical primates from the Belo Horizonte Zoo. METHODS: Vaccine 17DD was administered to 24 neotropical primates, with a single subcutaneous dose. Clinical exams, RNAemia, and detection of IgG and neutralizing antibodies against YFV were performed. In addition…

Endemicity of a Yellow Fever Virus Strain Revealed by Entomological Surveillance in Southeastern Senegal.

Yellow fever virus is an endemic mosquito-borne flavivirus that continues to cause outbreaks in human populations in Senegal despite the availability of a vaccine. Entomological surveillance was implemented in southeastern Senegal for the early detection of sylvatic amplifications, which usually trigger human cases. Mosquito vectors were collected monthly using Prokopack aspirators and double-net traps. Mosquitoes were pooled and tested by quantitative reverse transcription polymerase chain reaction assay targeting antigens of common arboviruses circulating in the area, and then positive sampl…

Ecological Requirements for Abundance and Dispersion of Brazilian Yellow Fever Vectors in Tropical Areas.

In the Americas, wild yellow fever (WYF) is an infectious disease that is highly lethal for some non-human primate species and non-vaccinated people. Specifically, in the Brazilian Atlantic Forest, Haemagogus leucocelaenus and Haemagogus janthinomys mosquitoes act as the major vectors. Despite transmission risk being related to vector densities, little is known about how landscape structure affects vector abundance and movement. To fill these gaps, we used vector abundance data and a model-selection approach to assess how landscape structure affects vector abundance, aiming to identify connect…

Совпадение с вирусом дезинфекции и Желтой лихорадки в неотропическом примате в Бразилии.

Мы описываем естественное примеси с вирусом дезтемпера (CDV) и вирусом желтой лихорадки в свободном неотропическом примате рода Каллитрикс, найденном мертвым в северо-восточной части Бразилии. Лабораторная диагностика включала гистопатологию, иммунохимию, РРТ-ПКР и филогенетические анализы. Последовательность CDV от этого примата в Бразилии представляет собой разную линию в Рио-Гранде-ду-Норте, тесно связанную с генотипами ЕС1/Южная Америка 1 и Южная Америка 2. Насколько нам известно, это первый доклад о естественном инфекции ВИЧ и вируса желтой лихорадки в неотропальном примате, в котором под

Совпадение в аннотации оригинала
We describe a natural coinfection with canine distemper virus (CDV) and yellow fever virus in a free-ranging neotropical primate of the genus Callithrix, found dead in the northeastern region of Brazil. The laboratory diagnosis included histopathology, immunohistochemistry, rRT-PCR, and phylogenetic analyses. The CDV sequences from this primate in Brazil rep…

Effects of migration rates and vaccination on the spread of yellow fever in Latin American communities.

OBJECTIVE: To assess how relevant the flow of people between communities is, compared to vaccination and type of vector, on the spread and potential outbreaks of yellow fever in a disease-free host community. METHODS: Using a SEIRV-SEI model for humans and vectors, we applied numerical simulations to the scenarios: (1) migration from an endemic community to a disease-free host community, comparing the performance of Haemagogus janthinomys and Aedes aegypti as vectors; (2) migration through a transit community located on a migratory route, where the disease is endemic, to a disease-free one; a…

Development, verification, and validation of an RT-qPCR-based protocol for Yellow Fever diagnosis.

INTRODUCTION: Yellow fever (YF) is a public health threat with frequent outbreaks in tropical and subtropical areas, despite the existence of a safe and effective vaccine. The diagnosis of acute infection of the etiologic agent relies mainly on real-time reverse transcription-polymerase chain reaction (RT-qPCR)-based assays. OBJECTIVES: The aim of this study was to evaluate and compare this novel protocol for yellow fever virus (YFV) diagnosis against assays developed in-house by reference laboratories for arboviruses. METHODS: We developed a novel molecular protocol for the detection of YFV…

Th22 cytokines and yellow fever: Possible implications for the immunopathogenesis of human liver infection.

Yellow fever (YF) is an infectious disease considered a public health problem in tropical and subtropical areas. YF has many pathophysiological events that are correlated with the host immune response. In this study, the in situ Th22 cytokine profile was evaluated. Liver tissue samples were collected from 21 YFV-positive patients who died of the disease and five flavivirus-negative controls who died of other causes and whose hepatic parenchyma architecture was preserved. Immunohistochemical (IHC) analysis of tissues in the hepatic parenchyma of YF cases showed significantly higher expression o…

An overview on small molecules acting as broad-spectrum agents for yellow fever infection.

INTRODUCTION: Yellow fever virus (YFV) is a mosquito-borne flavivirus, endemic in 47 countries in Africa and South America, which causes febrile symptoms that can evolve in 15% of the patients to serious hemorrhagic conditions, liver injury, and multiorgan failure. Although a highly effective vaccine (YF-17D vaccine) is available, to date, no antiviral drugs have been approved for the prevention and treatment of YFV infections. AREAS COVERED: This review article focuses on the description of viral targets that have been considered within YFV and flavivirus drug discovery studies and on the mo…

Development of a Bicistronic Yellow Fever Live Attenuated Vaccine with Reduced Neurovirulence and Viscerotropism.

The yellow fever (YF) live attenuated vaccine strain 17D (termed 17D) has been widely used for the prevention and control of YF disease. However, 17D retains significant neurovirulence and viscerotropism in mice, which is probably linked to the increased occurrences of serious adverse events following 17D vaccination. Thus, the development of an updated version of the YF vaccine with an improved safety profile is of high priority. Here, we generated a viable bicistronic YF virus (YFV) by incorporating the internal ribosome entry site (IRES) from Encephalomyocarditis virus into an infectious cl…

The resurgence of yellow fever outbreaks in Nigeria: a 2-year review 2017-2019.

BACKGROUND: Yellow fever outbreaks are documented to have a considerable impact not only on the individuals but on the health system with significant economic implications. Efforts to eliminate yellow fever outbreaks globally through the EYE strategy remains important following outbreaks in Africa, Nigeria included. The outbreaks reported in Nigeria, since 2017 and the response efforts provide an opportunity to document and guide interventions for improving future outbreaks in Nigeria and other countries in Africa. METHODS: We reviewed the available yellow fever surveillance and vaccination r…

Vaccine usage and wastage in a designated Yellow Fever Vaccination Centre in North India.

PURPOSE: Yellow fever is a viral hemorrhagic fever transmitted through the bite of mosquitoes. World Health Organization guidelines advocate a single dose of vaccine for life-long protective immunity against yellow fever. Yellow fever vaccine is included in routine childhood immunization schedules in countries at medium or high risk of yellow fever. For some travelers, visiting endemic countries, yellow fever vaccination is recommended to protect the travelers. We calculated the yellow fever vaccine wastage rate at a designated center in North India. MATERIALS AND METHODS: This is a record-ba…

Inactivation of yellow fever virus with amotosalen and ultraviolet A light pathogen-reduction technology.

BACKGROUND: The reemergence of yellow fever virus (YFV) in Africa and Brazil, and massive vaccine campaigns triggered to contain the outbreaks, have raised concerns over blood transfusion safety and availability with increased risk of YFV transfusion-transmitted infections (TTIs) by native and vaccine-acquired YFV. Blood donor deferral for 2 to 4 weeks following live attenuated YFV vaccination, and deferral for travel to endemic/epidemic areas, may result in blood donor loss and impact platelet component (PC) stocks. This study investigated the efficacy of INTERCEPT Blood System pathogen reduc…

Longitudinal dynamics of the human B cell response to the yellow fever 17D vaccine.

A comprehensive understanding of the development and evolution of human B cell responses induced by pathogen exposure will facilitate the design of next-generation vaccines. Here, we utilized a high-throughput single B cell cloning technology to longitudinally track the human B cell response to the yellow fever virus 17D (YFV-17D) vaccine. The early memory B cell (MBC) response was mediated by both classical immunoglobulin M (IgM) (IgM+CD27+) and switched immunoglobulin (swIg+) MBC populations; however, classical IgM MBCs waned rapidly, whereas swIg+ and atypical IgM+ and IgD+ MBCs were stable…

Completeness of yellow fever notification forms in the state of Espírito Santo, Brazil, 2017.

Objective to describe the completeness of data on yellow fever notification forms in the municipalities of the state of Espírito Santo, Brazil, in 2017. Methods this is a descriptive ecological study with data from the Notifiable Health Conditions Information System (SINAN); form completeness was categorized as poor (<70.0%), regular (70-89.9%) or excellent (≥90.0%); thematic maps were prepared. Results 53.1% of the municipalities had poor or regular classification for many notification form variables, especially case Final Classification (57.1%), Confirmation/Dismissal Criterion (63.2%) and C…

Midgut barriers prevent the replication and dissemination of the yellow fever vaccine in Aedes aegypti.

BACKGROUND: To be transmitted to vertebrate hosts via the saliva of their vectors, arthropod-borne viruses have to cross several barriers in the mosquito body, including the midgut infection and escape barriers. Yellow fever virus (YFV) belongs to the genus Flavivirus, which includes human viruses transmitted by Aedes mosquitoes, such as dengue and Zika viruses. The live-attenuated YFV-17D vaccine has been used safely and efficiently on a large scale since the end of World War II. Early studies have shown, using viral titration from salivary glands of infected mosquitoes, that YFV-17D can infe…

Iron and Ferritin Deposition in the Ovarian Tissues of the Yellow Fever Mosquito (Diptera: Culicidae).

Dengue, yellow fever, and Zika are viruses transmitted by yellow fever mosquito, Aedes aegypti [Linnaeus (Diptera: Culicidae)], to thousands of people each year. Mosquitoes transmit these viruses while consuming a blood meal that is required for oogenesis. Iron, an essential nutrient from the blood meal, is required for egg development. Mosquitoes receive a high iron load in the meal; although iron can be toxic, these animals have developed mechanisms for dealing with this load. Our previous research has shown iron from the blood meal is absorbed in the gut and transported by ferritin, the mai…

Yellow fever vaccine-associated neurological disease: it is not just the silver generation at risk.

A 35-year-old man presented to his optician with sudden onset diplopia and a 1-week history of headaches. He was noted to have sixth nerve palsy. The following day he was admitted to hospital with confusion and expressive dysphasia. He had been due to travel to Ghana on business and had received yellow fever (YF) vaccination 18 days prior to onset of headaches. His initial cerebrospinal fluid (CSF) revealed elevated protein, increased white cell count but was PCR negative for standard viral pathogens. Herpes simplex virus (HSV)-1 was detected by PCR in CSF at a very low level from a second lum…