# A Mini-Review of Diagnostic Methods for the Antigen and Antibody Detection of Rocky Mountain and Brazilian Spotted Fever

## TL;DR

This paper reviews current diagnostic methods for detecting antigens and antibodies in Rocky Mountain and Brazilian spotted fever, highlighting their limitations and the need for better techniques.

## Contribution

A systematic review of diagnostic methods for Rickettsia rickettsii with a focus on their accuracy and limitations.

## Key findings

- IFA was the most frequently used method but showed low specificity with the indirect method.
- ELISA and immunohistochemistry were less commonly used and have their own diagnostic limitations.
- There is a need for new diagnostic techniques to improve rapid and effective detection of R. rickettsii infections.

## Abstract

Rocky Mountain or Brazilian spotted fever, caused by Rickettsia rickettsii, is a fulminant, seasonal, and neglected disease that occurs in focal points of North America and South America. Its rapid detection is essential for the better prognosis and survival rate of infected individuals. However, disease diagnosis still faces challenges as the accuracy of many of the available laboratory tests fluctuates. This review aimed to analyze methods for antibody or antigen detection, their gaps, and their evolution over time. A search was conducted to find all studies in the Pubmed database that described the antibody or antigen detection of R. rickettsii infections. Initially, a total of 403 articles were screened. Of these articles, only 17 fulfilled the pre-established inclusion criteria and were selected. Among the different methods applied, the IFA technique was the one most frequently found in the studies. However, it presented varied results such as a low specificity when using the indirect method. Other techniques, such as ELISA and immunohistochemistry, were also found, although in smaller numbers and with their own limitations. Although some studies showed promising results, there is a pressing need to find new techniques to develop a rapid and effective diagnosis of R. rickettssi infection.