A Systematic Review and Meta-analysis of Scrub Typhus and its Association with Liver Disease

Scrub typhus is a vector-borne infection caused by the bacterium Orientia tsutsugamushi, transmitted to humans through the bite of larval forms of Leptotrombidium mites and hence called tsutsugamushi disease or rickettsial disease. The objective of the study is to assess the disease severity, laboratory investigations, and complications of scrub typhus with the association of liver diseases and mortality rate of scrub typhus.

Data sources PubMed, Cochrane, and Google Scholar were systematically searched for data published up to May 2024. The studies selected were all scrub typhus patients associated with liver diseases. The data extraction was done as per the preestablished checklist. The mean difference for liver function test (LFT)'s aspartate aminotransferease and alanine aminotransferase level was analyzed, and risk difference was evaluated with liver disease and mortality rate using RevMan 5.4 software. Data analyses were performed from 2019 to 2024 (PROSPERO Registration: ID CRD42024515922).

The analysis included a total of 901 scrub typhus cases with 554 cases associated with liver diseases. The study further investigated the LFT parameters, clinical symptoms, and 129 case mortality of scrub typhus. The meta-analyses showed that AST and ALT levels of scrub typhus patients had an overall significant effect in scrub typhus with liver disease (95% confidence interval [CI]: 135.81-153.15) with P < 0.00001 and scrub typhus with liver disease and mortality rate (risk ratio: 4.29 [95% CI: 3.64-5.07], P < 0.0001). A significant Q statistic P-value indicates the presence of heterogeneity, as reflected by high I2 values (I2 = 96% and I2= 78%).

61.50% scrub typhus with liver disease patients and 14.32% mortality rate in scrub typhus were evaluated. This study demonstrated an association betweeen scrub typhus and liver disease, highlighting its severity and the mortality rate among hospitalized patients.