Via ProMED-mail: Acute encephalitis syndrome - India (02): (Uttar Pradesh). Excerpt:
Source: a correspondent who has requested anonymity [edited]
The Gorakhpur encephalitis (AES) [acute encephalitis syndrome] mystery has been [resolved]. It is scrub typhus, a mite-borne bacterial disease, caused by Orientia tsutsugamushi.
An ICMR [Indian Council of Medical Research] sponsored investigation during August-September 2014 identified the etiology. Out of 249 acute encephalitis syndrome (AES) cases investigated, 152 (61 percent) of the cases were attributable to scrub typhus either by IgM ELISA, IFA or PCR. A pathognomonic eschar was evident in 20 per cent of the AES cases we investigated.
Scrub typhus is generally an acute febrile illness involving multiple organs. Encephalitis is a late manifestation with high mortality. Scrub typhus is a treatable bacterial disease with excellent clinical response from doxycycline and azithromycin treatment. If left untreated for over a week, scrub typhus may lead to encephalitis, myocarditis, or multi-organ failure. Early administration of doxycycline during the 1st week of the febrile phase can prevent clinical complications in scrub typhus. In severe cases of scrub typhus, early and appropriate administration of intravenous azithromycin or doxycycline may save lives.
Seasonality of scrub typhus in Gorakhpur coincides with monsoon (July-September). Scrub vegetation during this season enhances transmission.
Early case identification and appropriate doxycycline therapy at community levels during monsoon will reduce the incidence of encephalitis.
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[This report adds another dimension to the etiologies of acute encephalitis syndrome (AES) in northeastern India. A 22 Sep 2015 report indicated that there were 10 834 AES cases in 2014. That report describes AES as, "a group of clinical neurologic manifestations caused by a wide range of viruses, bacteria, fungi, parasites, spirochetes, chemicals and toxins" (http://zeenews.india.com/news/health/health-news/india-had-over-10000-acute-encephalitis-syndrome-cases-in-2014_1800724.html).
Previous ProMED-mail posts have implicated Reye syndrome, consumption of lychees, and heat stroke, as well as Japanese encephalitis virus infections, as responsible for AES. Now, scrub typhus is added to the list. Although "gold standard" diagnostic tests for scrub typhus were employed in the above study, there is no mention that these other etiologies were ruled out. One should note that 61 percent of the samples tested were scrub typhus positive, leaving 39 percent of the AES cases without a diagnosis.
The contributor of this report is thanked, and one hopes that this study will lead to testing for scrub typhus as other AES cases occur