Recent CHIKV infection was associated with various neurological complications, suggesting neurotropic nature of the virus. The outcome of the neurological complications is likely to be good.

The detection of ESAT-6 in the CSF of TBM patients by indirect ELISA is a promising method and can be used to develop an immunodiagnostic assay with increased sensitivity and specificity.

BackgroundDuring Chikungunya virus (CHIKV) epidemic in Nagpur, India, we identified some suspected Chikungunya patients with neurological complications. Early and cost-effective diagnosis of these patients remains problematic despite many new advanced diagnostic methods. A reliable diagnostic test, which could be performed in any standard pathology laboratory, would help to obtain definitive early diagnosis of CHIKV patients with neurological complications. In our laboratory, in-house ELISA protocol for viral antigen, immunoglobulin M (IgM) and IgG detection has been developed and assessed for the diagnosis of CHIKV patients with neurological complications.MethodCerebrospinal fluid samples of forty-six patients who developed neurological symptoms within two months of CHIKV infections along with control subjects were included in the study and were analyzed for the presence of antigens and of IgM and IgG using an ELISA protocol.ResultsThe ELISA method for antigen detection yielded 80% sensitivity and 87% specificity for the diagnosis of CHIKV patients with neurological complications. The sensitivity for detection of IgM 48% or IgG 63% was significantly lower than the antigen assay (80%).ConclusionThe detection of viral antigen in CSF of CHIKV patients with neurological complications by ELISA method gave a more reliable diagnosis than antibodies detection that can be used to develop an immunodiagnostic assay with increased sensitivity and specificity.

A Chikungunya virus (CHIKV) outbreak continues in India. Monitoring of the clinical features of CHIKVinfection is an important component of assessing the disease process. Diagnosis is usually made by an immunoglobulin M (IgM)/IgG enzyme-linked immunosorbent assay (ELISA). However, these assays have extremely low sensitivities for the detection of infection in the majority of CHIKV patients during the acute stage of infection (during the 1 to 4 days after infection). In our laboratory, a sensitive ELISA protocol for antigen detection has been developed for the detection of CHIKV infection in the acute stage, and in the present study we assessed the usefulness of this ELISA-based system for the detection of CHIKV infection. We performed a prospective, double-blinded study of 205 Indian patients with suspected CHIKV infection in the Nagpur District. All patients underwent a full clinical assessment, and their serum samples were analyzed for the presence of antigens and of IgM and IgG by an ELISA protocol. In patients with CHIKV infection, the sensitivity of antigen detection was 85%, which was significantly higher (P < 0.001) than that of IgM (17%) or IgG (45%) detection. The sensitivity of IgM (20%) or IgG (25%) detection was significantly lower than that of the antigen assay (95%) for patients with acute infections (i.e., from day 1 to day 5 after infection). Antigen detection not only gives a positive confirmatory result in the early phase of the disease, but it is also useful in the prodromal and subclinical stage and may be useful for field applications for the rapid detection of CHIKV infection.

Background: Chikungunya infection caused by Chikungunya virus (CHIKV) is an inflammatory disease affecting the joints and may also lead to neurological complications. We investigated a panel of human Toll-like receptor (TLR)-induced cytokines in Chikungunya patients with and without neurological complications. Methods: In a case-control study, a panel of 12 cytokines and chemokines, TNF-α, IFN-α, IL-1β, IL-6, IL-12, IL-17A, IL-8, monocyte chemotactic protein (MCP)-1, RANTES, interferon (IFN)-γ-induced protein (IP)-10, monokine induced by IFN-γ (MIG) and thymus and activation-regulated chemokine (TARC), was analysed using a conventional ELISA protocol in the serum samples of Chikungunya patients without neurological complications and in the cerebrospinal fluid (CSF) and paired serum samples of Chikungunya patients with neurological complications. Results: The levels of 3 cytokines, IL-1β, IL-17A and IL-8, and 4 chemokines, MCP-1, RANTES, IP-10 and TARC, were raised in serum samples of Chikungunya patients without neurological complications, whereas, 4 cytokines, TNF-α, IFN-α, IL-6 and IL-8, and 4 chemokines, MCP-1, RANTES, MIG and TARC, were elevated in CSF samples of Chikungunya patients with neurological complications. Moreover, the levels of IL-6 and IL-8 cytokines were significantly elevated in the CSF compared to paired serum samples in Chikungunya patients with neurological complications. Conclusions: In CHIKV infection, multiple cytokines are elevated in serum and CSF. The elevation in IL-6 and IL-8 cytokines in CSF correlates with neurological involvement.