The contributions of James Carmichael Smyth, Archibald Menzies and Robert Jackson to the treatment of typhus in royal naval vessels in the late 18th century

In late 18th century Britain, typhus fever plagued the mass mobilisation of soldiers and posed a significant challenge to physicians of the time. Epidemic typhus was spread through highly infectious faeces of infected lice and carried a high mortality in patients and healthcare staff alike. Physicians James Carmichael Smyth (1741-1821) and Archibald Menzies (1754-1842) theorized that typhus fever was caused by infection of human exhalation. They trialled the use of vapourised nitrous acid to fumigate patients, their clothes and their bedspace, with apparent success. Despite this, typhus fever continued to ravage deployments of soldiers into the early 19th century, stimulating the continuing evolution of the understanding of typhus and its treatment.

An overview of rickettsiae in Southeast Asia: Vector-animal-human interface

Rickettsioses are emerging, and re-emerging diseases caused by obligate intracellular arthropod-borne bacteria that infect humans and animals worldwide. Various rickettsiae such as Orientia, Rickettsia, Anaplasma and Ehrlichia have been circulated in companion, domesticated and wild animals through bites of infected ticks, fleas, lice or mites. This review summarizes the infections of rickettsiae, including the newly discovered regional species Rickettsia thailandii, Candidatus Rickettsia sepangensis, Candidatus Rickettsia johorensis, Candidatus Rickettsia laoensis, Candidatus Rickettsia mahosotii, Candidatus Rickettsia khammouanensis, Candidatus Anaplasma pangolinii, and other novel genotypes in vectors, humans and animals in Southeast Asia. Issues on some unidentified rickettsiae that elicit immune responses and production of antibodies that are cross-reactive with the antigens used are discussed. Knowledge gaps which required attention are also identified in this review.