Hemagglutination With Arthropod-Borne Viruses

Abstract

Through the use of acetone and ether extraction of brain tissue from newborn mice infected with certain arthropod-borne viruses, it has been possible to demonstrate hemagglutinins for chick erythrocytes associated with the following viruses: dengue Type 1, dengue Type 2, Eastern equine encephalitis, Ilhéus, Japanese B, Ntaya, St. Louis, Sindbis, Uganda S, Venezuelan equine encephalitis, West Nile (Egypt 101 strain), Western equine encephalitis, and yellow fever (viscerotropic and neurotropic strains). On the basis of the temperature and pH required for reaction, the viruses can be assembled in two groups: A—those that require 37°C. and a pH of about 6.4, comprising Eastern, Venezuelan, and Western equine encephalitis and Sindbis viruses; and B—those that require either 4° or 22°C. and a pH of about 7.0, comprising dengue Types 1 and 2, Ilhéus, Japanese B, Ntaya, St. Louis, Uganda S, West Nile, and yellow fever viruses. A method of eliminating non-specific inhibitory substances present in sera was developed. The method consists essentially of filtration through Seitz pads. Extensive serological crossings were found among viruses of each group, while antisera of one group failed consistently to cross-react with antigens of the other. Antisera deriving from animals immunized with certain viruses for which no hemagglutinins could be developed by the present method, reacted with members of either one or the other group. Thus Semliki Forest virus would appear to belong to Group A, and Russian Far Eastern and louping ill viruses to Group B.

Detection of arboviruses of public health interest in free-living New World primates (Sapajus spp.; Alouatta caraya) captured in Mato Grosso do Sul, Brazil

“…However, it is a more sensitive and accurate technique than methods that use large sample volumes, enabling savings in time and reagents. The HI test is an ideal method for detecting antibodies in wild animals captured in forests 19 .…”

“…The seru m samples from the 16 animals were analyzed using the hemagglutination inhibition test (HI) and a p anel of 19 The HI t est used in the present study was standardized by the Section of Arbovirology and Hemorrhagic Fevers (SAARB) of the I nstituto Evandro Chagas (IEC) followin g the protocol described by Clarke and Casals 17 , as adapt ed for microplates by Shope 18 .…”

“…The anti gens used were pre pared from the brains and/or serum of newborn infected mice using t he sucrose-acetone and sorovirus extraction methods, respectively 19 . The seru m samples were pre-treated with acetone to remove natural inhibitors, and they were adsorbed on goose erythrocytes (Anser cinereus) 20 to remove non-specific agglutinins that mig ht inhibit the agglutination of red blood cells, thereby avoiding false-positive results.…”

Single point mutations in the helicase domain of the NS3 protein enhance dengue virus replicative capacity in human monocyte-derived dendritic cells and circumvent the type I interferon response

“…Furthermore, NS3 has a pivotal function in viral particle assembly; namely, in the cleavage of the C-prM precursor by the NS2B-NS3 protease [14,15]. The four dengue serotypes are referred to as DV1, DV2, DV3 and DV4 and are closely related [16][17][18]. Infection with any one of the four DVs can cause a spectrum of clinical manifestations, ranging from self-limiting non-symptomatic disease to dengue fever (DF), with symptoms including headache, fever, arthralgia, myalgia, nausea, vomiting and/or rashes [19,20].…”

An investigation of flavivirus infections of cattle in Zimbabwe Rhodesia with particular reference to Wesselsbron virus

“…In order to investigate the role played by the virus in the field, it is necessary to determine whether antibodies demonstrated in sera are due to infection with WSL virus or some otber flavivirus. Members of the genus are grouped together on the basis of their cross-reactivity in the HAI test (Casals & Brown, 1954). Antisera are less cross-reactive in the complement-fixation (CF) test and show greatest specificity for individual viruses in the neutralization (NT) test, but cross-reactivity in all tests is greatly increased where consecutive infection occurs with two or more members of the group (Casals, 1957(Casals, , 1961(Casals, , 1963.…”