Device and methods

Abstract

The present invention relates generally to methods and materials pertaining to assays, for example immunoassays, for biomarkers in body fluids e.g. blood. The invention also relates to diagnostic or screening methods for infections, and methods of differentiating between infectious and non-infectious conditions in mammals, particularly equines, for monitoring response to anti-infective/antibiotic therapy. The invention further relates to a test fluid collection system adapted to permit dilution and analysis of the collected test fluid. The invention further relates to monitoring exertional rhabdomyolysis in equines, and assay devices for all these things.

1 . (canceled) 
     
     
         2 . A method of distinguishing infectious diseases from non-infectious aetiologies in a mammal exhibiting an inflammatory response, the method comprising distinguishing whether the concentration of Serum Amyloid A (SAA) in a body fluid sample of said mammal is either below or above a specified level; wherein:
 (i) if the concentration of SAA is below the specified level it indicates that the inflammatory response results from a non-infectious disease; wherein said specified level is 15 μg/ml;   (ii) if the concentration of SAA is above the specified level it indicates that the inflammatory response results from an infectious aetiology; wherein said specified level is 15 μg/ml.   
     
     
         3 . The method as claimed in  claim 2  wherein said specified level for (ii) is 20, 25, 30 or 50 μg/ml. 
     
     
         4 . The method of diagnosing an infectious disease in a mammal, or confirming an infectious disease in a mammal, the method comprising performing the method of  claim 2 , and diagnosing or confirming the infectious disease if the concentration of SAA is below or above the specified level in (i) and (ii), respectively. 
     
     
         5 . The method of identifying a non-infectious aetiology in a mammal, or confirming a non-infectious aetiology in a mammal, the method comprising performing the method of  claim 2  and identifying or confirming the non-infectious aetiology if the concentration of SAA is below the specified level. 
     
     
         6 . The method as claimed in  claim 2  wherein the infectious disease is one caused by bacterial infection or viral infection; or wherein the non-infectious aetiology is an inflammatory disorder. 
     
     
         7 . The method as claimed in  claim 2  wherein the method is for distinguishing a bacterial lung infection from a non-infectious aetiology, wherein optionally in (ii) a concentration of SAA of above 30 μg/ml is observed in the case of the infection. 
     
     
         8 . The method as claimed in  claim 2 , wherein SAA concentrations of 7.5-200 μg/ml may indicate the presence of subclinical infection and SAA concentrations over 200 μg/ml may indicate clinical infection. 
     
     
         9 . A method of detecting or screening for infectious disease in an asymptomatic mammal, the method comprising distinguishing whether the concentration of Serum Amyloid A (SAA) in a blood sample of said mammal is either below or above a specified level; wherein a concentration of SAA is above the specified level of 15 μg/ml indicates a likelihood of infectious disease compared to whether the concentration of SAA is below the specified level of 15 μg/ml. 
     
     
         10 . The method as claimed in  claim 9  wherein the mammal is a neonate mammal, which is optionally a foal age 8-10 hours or up to 10, 12, 24, 48, or 72 hours; and wherein the screening method is optionally repeated every 7, 8, 9, 10, 11, 12, 13, or 14 days for at least the first 8, 9, 10, 11 or 12 weeks of life. 
     
     
         11 . The method as claimed in  claim 2  wherein if the concentration of SAA is above the specified level, the mammal is selected for an anti-infective treatment. 
     
     
         12 . The method as claimed in  claim 2  wherein if the concentration of SAA is above the specified level, the method further comprises a treatment step, the treatment step optionally comprising:
 (i) a period of rest for the mammal; and/or 
 (ii) administration of an anti-infective, which is optionally an antibiotic if the infection is inferred to be a bacterial infection. 
 
     
     
         13 . A method of monitoring recovery of a mammal from an infectious disease, the method comprising
 (i) determining the level of Serum Amyloid A (SAA) in a body fluid sample from the mammal,   (ii) repeating step (i) after a defined period; and   (iii) optionally repeating step (ii),   wherein a defined decrease in the level of SAA over a defined period indicates the condition is improving or that the mammal has recovered from the disease,   wherein the defined decrease is at least 50%, and wherein the defined period is selected from 6, 12, 18, 24, 48 and 72 hours.   
     
     
         14 . The method as claimed in  claim 13  wherein the recovery is in response to treatment of the infection; and wherein the treatment is optionally by an anti-infective, which is optionally an antibiotic. 
     
     
         15 . The method as claimed in  claim 13  wherein when the recovery is in response to treatment of the infection; and wherein the treatment is optionally by an anti-infective, which is optionally an antibiotic, the monitoring method is performed to determine whether to withdraw or change the treatment. 
     
     
         16 . The method as claimed in  claim 2  wherein the distinguishing whether the concentration of SAA in a body fluid sample of said mammal is either below or above a specified level is carried out by using a portable lateral flow device (LFD) comprising a housing and a flow path heading from a sample well to a viewing window, through which the body fluid sample can flow by capillary action, wherein said device provides a signal in the viewing window which indicates whether the SAA is below or above the specified level; and wherein said device optionally measures SAA concentration over at least the range of 0 to 3000 μg/ml. 
     
     
         17 . The method of distinguishing infectious diseases from non-infectious aetiologies in a mammal exhibiting an inflammatory response as claimed in  claim 2  using a diagnostic or prognostic device,
 wherein said device is a portable lateral flow device (LFD) for measuring SAA in a sample derived from the mammal, wherein said LFD comprises: 
 (i) a housing, and 
 (ii) a flow path leading from a sample well to a viewing window on the housing, through which the body fluid can flow by capillary action; 
 wherein the presence of SAA is detected by the anti-SAA antibody and produces a line in the viewing window which indicates an SAA concentration of at or above 15 μg/ml in the body fluid sample.