Aftershocks of scrub typhus in Nepal - Author's reply.

Abstract

I agree with Hemant Ojha and Sampanna Jung Rayamajhi that, although the suggestion to use doxycycline for treatment of a presumptive diagnosis of scrub typhus is justified,1Basnyat B Typhoid versus typhus fever in post-earthquake Nepal.Lancet Glob Health. 2016; 4: e516-e517Summary Full Text Full Text PDF PubMed Scopus (23) Google Scholar we clearly have to be on the lookout for doxycycline-resistant scrub typhus. Indeed, the Comment was written in an attempt to serve as a wake-up call for more research on both typhus and typhoid, especially regarding reliable, rapid diagnostic tests to distinguish between these kinds of undifferentiated febrile illnesses in the tropics. Undifferentiated febrile illnesses are defined as fever without a clear-cut focus of infection. The necessity of rapid diagnostics is brought home by the fact that the first two references2Watt G Chouriyagune C Ruangweerayud R et al.Scrub typhus infections poorly responsive to antibiotics in northern Thailand.Lancet. 1996; 348: 86-89Summary Full Text Full Text PDF PubMed Scopus (217) Google Scholar, 3Corwin A Soderquist R Suwanabun N et al.Scrub typhus and military operations in Indochina.Clin Infect Dis. 1999; 29: 940-941Crossref PubMed Scopus (39) Google Scholar cited in support of Ojha and Rayamajhi's argument deal with not only proven but also suspected cases of scrub typhus. Because of the substantial overlap in symptoms between typhus, typhoid, and other undifferentiated febrile illnesses, such as malaria, dengue fever, and leptospirosis, it is important to make the right diagnosis so that treatment can be specific. Furthermore, Ojha and Rayamajhi seem to suggest rifampicin as a potential option in the treatment of scrub typhus. However, in many low-income and middle-income countries where scrub typhus is common, tuberculosis is also widespread. Therefore, it might be more prudent to reserve rifampicin for the treatment of tuberculosis. Ojha and Rayamajhi also mention that a single dose of azithromycin might be good enough for scrub typhus. However, it has to be emphasised that even if we find the various serotypes of scrub typhus in Nepal, in the present context, without reliable, rapid diagnostics it might be hazardous to use a single dose of azithromycin for undifferentiated febrile illnesses if diseases such as leptospirosis, which are common in Nepal,4Murdoch DR Woods CW Zimmerman MD et al.The etiology of febrile illness in adults presenting to Patan Hospital in Kathmandu, Nepal.Am J Trop Med Hyg. 2004; 70: 670-675Crossref PubMed Scopus (151) Google Scholar are lurking in the background because they might require more sustained treatment. Finally, I completely agree that more research needs to be done regarding scrub typhus, especially since this disease was brought sharply into focus in post-earthquake Nepal, which, as Ojha and Rayamajhi note, falls in the tsutsugamushi triangle. However, this claim regarding location is not substantiated by the WHO scrub typhus map.5WHO Regional Office for South-East AsiaFrequently asked questions scrub typhus.http://www.searo.who.int/entity/emerging_diseases/CDS_faq_Scrub_Typhus.pdfGoogle Scholar I declare no competing interests. Aftershocks of scrub typhus in NepalFollowing the devastating earthquake in 2015, outbreaks of scrub typhus have been reported in Nepal, a country situated in the tsutsugamushi triangle. Buddha Basnyat1 (August, 2016) points out the diagnostic dilemma faced by resource-limited Nepal, and outlines a plan for empirical treatment for undifferentiated fever. In the present context of Nepal, Basnyat's view on the use of doxycycline as an empirical agent for undifferentiated febrile illness is justifiable.1 However, we would like to highlight that suspected and proven doxycycline-resistant scrub typhus2–4 and strains with reduced clinical susceptibility to doxycycline, as compared with other drugs such as rifampicin, have been well documented. Full-Text PDF Open Access