An in vitro method for concentrating infectious pathogens present in a biological sample obtained from a subject who is suspected of being infected with said pathogens, the method comprising: (a) contacting the biological sample previously obtained from the subject with an adsorption media under conditions to form an adhering complex comprising the adsorption media and said pathogens, wherein the adsorption media is a solid substrate of high surface area having at least one polysaccharide adsorbent on the surface thereof; (b) separating the adhering complex from components of the sample that are not included in the complex while maintaining the complex; (c) washing the adhering complex with a wash buffer; and (d) collecting pathogens of the adhering complex by applying an elution buffer to the complex, thereby concentrating the infectious pathogens in an eluent; or alternatively, (i) contacting the biological sample obtained from said subject with an adsorption media to form an adhering complex comprising the adsorption media and a pathogen present in the sample, wherein the adsorption media is a solid substrate of high surface area having at least one polysaccharide adsorbent on the surface thereof; and (ii) determining presence of the adhering complex by detecting a physical change to the adsorption media; and (iii) predicting that the subject is infected by the infectious pathogen based on the physical change to the adsorption media compared to a reference adsorption media that has been contacted with a control sample. (a) contacting the biological sample previously obtained from the subject with an adsorption media under conditions to form an adhering complex comprising the adsorption media and said pathogens, wherein the adsorption media is a solid substrate of high surface area having at least one polysaccharide adsorbent on the surface thereof; (b) separating the adhering complex from components of the sample that are not included in the complex while maintaining the complex; (c) washing the adhering complex with a wash buffer; and (d) collecting pathogens of the adhering complex by applying an elution buffer to the complex, thereby concentrating the infectious pathogens in an eluent; or alternatively, (i) contacting the biological sample obtained from said subject with an adsorption media to form an adhering complex comprising the adsorption media and a pathogen present in the sample, wherein the adsorption media is a solid substrate of high surface area having at least one polysaccharide adsorbent on the surface thereof; and (ii) determining presence of the adhering complex by detecting a physical change to the adsorption media; and (iii) predicting that the subject is infected by the infectious pathogen based on the physical change to the adsorption media compared to a reference adsorption media that has been contacted with a control sample. (i) contacting the biological sample obtained from said subject with an adsorption media to form an adhering complex comprising the adsorption media and a pathogen present in the sample, wherein the adsorption media is a solid substrate of high surface area having at least one polysaccharide adsorbent on the surface thereof; and (ii) determining presence of the adhering complex by detecting a physical change to the adsorption media; and (iii) predicting that the subject is infected by the infectious pathogen based on the physical change to the adsorption media compared to a reference adsorption media that has been contacted with a control sample.