Lateral Flow Rapid Tests (RDT’S)
Overview
Lateral flow tests are commonly referred to as rapid diagnostic tests (RDTs) because they give fast, on-the-spot diagnostic results for conditions and diseases. RDTs bypass the standard laboratory, allowing testing to take place “in the field” or “at the point-of-care”. They can be adopted for human, veterinary and agricultural diagnostic purposes and are generally able to provide good sensitivities, specificities, reproducibility, with great user friendliness and compliance.
Because faster decision making takes place, RDTs offer faster diagnosis, better monitoring and earlier treatment. RDTs are generally much more affordable than the equivalent laboratory tests and can be mass produced and enrolled in various forms.
RDTs employ immunoassay technology through a combination of antibodies or antigens, nitrocellulose membranes and gold nanoparticles to produce a visual, qualitative result. Recent developments have shown that aptamers, affirmers or other novel reagents can also be incorporated in the RDT platform.
Brucellosis
Brucellosis is a zoonosis caused by Brucella abortus, B. suis and B. melitensis. Clinical manifestation of brucellosis in humans are variable and often are non‐specific, and the diagnosis requires confirmation by laboratory testing. In contrast, the primary clinical sign in bovines is abortion, which usually occur after five months of gestation due to placentitis. Abortions often occur as an abortion storm in naïve herds, whilst abortions will happen sporadically in affected herds, with infertility being a common occurrence in cows and decreased fertility in affected bulls. Decreased milk production, mastitis, epididymitis, and lameness are generally observed in infected herds.
LifeSADX produces brucellosis lateral flow assays (RDTs) which provide an indirect measure for infection through the detection of specific antibodies. Specific IgM antibodies usually predominate early in the disease. Specific IgG antibodies may remain present for a much longer period and predominate in persistent infections and during relapse. Test‐it™ Brucella IgM and IgG lateral flow assays are relatively simple and rapid assays. The assays do not require special training, equipment, or electricity. Results are obtained in 15 minutes. The assays and the running buffer can be stored at +4°C to +28°C.
Leptospirosis
Leptospirosis is also referred to as Weil’s disease and is caused by pathogenic spirochetes belonging to the genus Leptospira. In humans, leptospirosis is a mild, influenza-like illness that may develop into the more acute form called Weil’s syndrome characterized by jaundice, renal failure, haemorrhage and myocarditis. Meningitis and pulmonary haemorrhage with respiratory failure may also occur. Laboratory testing is essential because signs and symptoms may resemble those of other common infectious diseases. Humans react to the disease by producing anti-Leptospira antibodies. Seroconversion may occur as early as 5-7 days after the onset of disease. Acute disease is characterized by the presence of specific IgM antibodies.
Dogs can become infected by the bacteria entering skin wounds. The bacteria can be found in stagnant water such as ponds and lakes. Leptospirosis can cause a range of clinical signs from mild lethargy to liver disease and kidney disease in dogs can be very sick with fever, vomiting and diarrhoea along with signs of liver and kidney failure. The Test‐it™ Leptospira canine RDT was developed to diagnose severe acute icteric leptospirosis in dogs. Dogs are natural hosts to a variety of serovars which do not cause disease or, will cause mild disease only. Since most of the cases of severe icteric disease are caused by serogroup icteroheamorrhagiae, the assay is primarily based on the detection of such serovars. However, since the test is based on the detection of IgM antibodies, and these broadly cross-react with other serovars, reactivity can also be expected with other serovars during the acute stage of infection. This would imply that any dog with acute disease, the test would react positive because of the presence of these broadly reactive IgM antibodies during the acute stage.
The microscopic agglutination test is the reference test for leptospirosis and detection of specific IgM antibodies may be used for the early diagnosis. The Test-it™ Leptospira IgM lateral flow assay is a relatively simple and rapid assay that may be used as a point-of-care assay. The test does not require special training, equipment, electricity or refrigeration. Results are obtained in 15 minutes. The assay devices and the running buffer may be stored at +4°C to +28°C.
Typhoid Fever
Salmonella enterica serotype Typhi. The clinical presentation of typhoid fever varies from a mild illness with low-grade fever, malaise, and slight dry cough to a severe clinical picture with abdominal discomfort and multiple complications. Laboratory testing is essential because signs and symptoms may resemble those of other major infectious diseases. The Test-it™ Typhoid IgM lateral flow assay provides an indirect measure for infection through the detection of pathogen specific antibodies. Specific IgM antibodies usually develop early in the disease. The assay is a relatively simple and rapid assay that may be used as a point-of-care test in the field or at the bed-side. It does not require special training, equipment, electricity nor refrigeration. Results are obtained in 15 minutes. The assay devices and the running buffer may be stored at +4°C to +28°C.
LifeSADX supplies the following highly specialised lateral flow RDTs:
HUMAN RANGE
Test‐it™ Brucella IgM (BRU001) Serum, whole blood 25 tests/kit
Test‐it™ Brucella IgG (BRU002) Serum, whole blood 25 tests/kit
Test‐it™ Leptospira IgM (LEP001) Serum, whole blood 25 tests/kit
Test‐it™ Typhoid IgM (TYP001) Serum, whole blood 25 tests/kit
VETERINARY RANGE
Test‐it™ Brucella bovine IgTotal (BRU003) Serum, blood25 tests/kit
Test‐it™ Leptospira canine IgM (LEP001) Serum, blood25 tests/kit
