Evaluation of enzyme-linked immunosorbent assay and reversed passive hemagglutination for detection of Crimean-Congo hemorrhagic fever virus antigen

Abstract

Enzyme-linked immunosorbent assay (ELISA) and a reversed passive hemagglutination (RPHA) test were evaluated for rapid detection of Crimean-Congo hemorrhagic fever (CCHF) virus antigens. Both RPHA and ELISA detected CCHF antigen in the brains of infant mice 2 to 3 days after infection, several days before the animals sickened and died. Antigen was also detected after 1 to 2 days in infected cell culture extracts and after 2 to 4 days in culture supernatant fluids. Both tests detected CCHF antigen at threshold values of approximately 2.5 log1, tissue culture infective doses per ml and were more sensitive than complement fixation, immunodiffusion, or immunofluorescence. In a comparative study on specimens from CCHF patients, virus was isolated from 38 of 49 sera and 23 of 28 patients. Antigen was detected in 20 of 49 sera (15 of 28 patients) by RPHA and in 29 of 49 sera (18 of 28 patients) by ELISA. Antigenemia was detected more frequently in fatal cases (9 of 11) than in nonfatal cases (9 of 17). Although the antigen detection assays offered a more rapid approach than infectivity assays for diagnosing CCHF, the latter test was more sensitive. The results suggest that RPHA and ELISA may be of use in rapid diagnosis of CCHF infection, particularly in severe cases, in which the danger of nosocomial spread is greatest.

Short Report: Crimean-Congo Hemorrhagic Fever Outbreak in Rawalpindi, Pakistan, February 2002

“…Since viremia is more profound and intense in fatal cases, they have the greatest potential for nosocomial transmission. 28,29 The secondary cases were most likely exposed to the index case in the hospital. Both of the secondary cases became symptomatic within five days of the exposure to index case.…”

Diagnostic tests for Crimean-Congo haemorrhagic fever: a widespread tickborne disease

“…Most assays target the CCHFV N protein, which induces an early, strong and long-lasting immune response in humans 86. Active CCHFV infection can be detected by IgM or a significant increase in IgG titre following the acute phase of infection 4–9 days after symptom onset; however, severe and fatal cases often do not mount a detectable antibody response 79 87 88. Detection of anti-CCHFV IgG can indicate current or resolved infection (often years after infection) and can be useful in surveillance epidemiological studies.…”

“…Detection of anti-CCHFV IgG can indicate current or resolved infection (often years after infection) and can be useful in surveillance epidemiological studies. For CCHFV, capture ELISA has been shown to be more sensitive than IFA or neutralisation assay 87–89. Virus neutralisation assays are less useful for diagnosis, since CCHFV elicits relatively low levels of neutralising antibodies, but can be useful for epidemiology and vaccine research.…”

Crimean-Congo Hemorrhagic Fever: Current Scenario in India

“…This can delay the timely diagnosis and in turn early management of patients. Detection of immunoglobulin M (IgM) during the acute phase and immunoglobulin G (IgG) antibodies in convalescent phase sera is detectable by enzyme-linked immunosorbent assay (ELISA) and immunofluorescent antibody (IFA) [63,64]. Patients with fatal disease as well as patients in the first few days of illness do not usually develop a measurable antibody (IgM) response and in these individuals diagnosis is achieved either by virus detection in blood, serum, plasma, urine or tissue samples using molecular techniques.…”