No abstract

Background: Tuberculous meningitis (TBM) is one of the common clinical manifestations of extra-pulmonary tuberculosis. It is difficult to diagnose due to a lack of rapid, sensitive, and specific tests. Newer methods, which are easy and reliable, are required to diagnose TBM at an early stage. Thus our aim was to evaluate the polymerase chain reaction (PCR) technique, using primers directed against the IS6110 gene, for the detection of Mycobacterium tuberculosis in the CSF, for the diagnosis of TBM patients.

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.