Rickettsial diseases and particularly, scrub typhus is one of the oldest recognized vector transmitted zoonosis [1]. The World Health Organization has reported scrub typhus one of the world’s most under diagnosed and under reported disease that often requires hospitalization. Better understanding of the vectors, its outbreaks and its pathogenesis is required to control human outbreaks within and beyond its recognized regions of endemicity [2].

Himachal Pradesh is a mountainous state in northern India, situated at an altitude between 350-6816 meters above mean sea level [3]. During the rainy seasons, areas of lower altitudes experience an average temperature between 20ºC to 35ºC which is suitable for the spread of arthropod vector. Maximum number of the cases are being reported between the months of July to November [4].

Scrub typhus is an acute febrile illness caused by O. tsutsugamushi [5]. The most characteristic clinical feature of Scrub typhus is the presence of an eschar at the site of the bite of the mite which is confirmatory of Scrub. The eschar starts as a small papule, at the site of chigger feeding and then ulcerates and forms a black crust like a skin burn from a cigarette [6]. The prevalence of an eschar is highly variable, from 7 to 80% in various studies, and this variation maybe due to difficulties in identifying the eschar in dark skinned individuals, differences in the eschar inducing capacity of different strains of the organism, and the atypicalappearance of eschars in skin folds and moist skin [7].

The groin, axilla, waist, neck and other exposed parts of the body are common sites.When present, it occurs prior to the onset of fever and other symptoms and develop on the front of the body (~80%) . Towards the end of the first week, a maculopapular rash starting on the trunk and spreading to the limbs may be seen [6].

Scrub typhus is a well documented disease in the state of Himachal Pradesh, but there have been no studies on ecshar which is associated with the exposure to Orientia tsutsugamushi in the paediatric age group population. Therefore, this study was done to determine the prevalence as well as the most common sites of eschars over the bodies of patients with Scrub typhus 

Aims and Objectives

To determine the prevalence as well as the most common sites of eschars over the bodies of patients with Scrub typhus

This study was conducted in the department of Paediatrics, Indira Gandhi Medical College, Shimla, a tertiary care teaching institute in Himachal Pradesh. 

Duration of Study

From 1^st June 2017 to 30^th Nov 2018.

Study Design

Cross-sectional Study.

Ethical Clearance: 

Approval from the Institutional ethical committee of Indira Gandhi Medical College Shimla.

Study Population           

The study participants consisted of all 102 newly diagnosed paediatric cases of scrub typhus, admitted in pediatric ward of IGMC Hospital Shimla based on positive IgM against scrub typhus during the study period.

Exclusion Criteria 

• The study subjects having concomitant HIV, Malaria, Tuberculosis, Hepatitis, Typhoid and Acinetobacter septicaemia.

• Participants in the control group B and group C having febrile illness during the last three months. 

• Participants or their parents who are not willing to participate in the study.

Sampling Method 

All the diagnosed cases of scrub typhus based on enrolment criteria at the time of admission in the paediatric ward were enrolled 

Statistical Analysis

Data from the case record files was recorded on a Microsoft excel spreadsheet. Statistical analysis was performed using Epi Info 7. All discrete variables were expressed as percentages. 

In the present study, among 102 newly diagnosed cases of Scrub Typus, 57 (55.9%) were males while 45 (44.1%) were females. Eshar was present in 39(38.24%) patients. Among these 39 patients 21(53.8%) were males while 18 (46.2%) were females.

Location of Eschar

It was most commonly seen in inguinal 9(23.1%), abdomen 7(17.9%), chest (17.9%), axilla 6 (15.4%), lower limbs 4 (10.3%), forearm 3(7.7%), head and neck 2(5.1%) and multiple sites 1(2.6%). There was a significant difference in the distribution of eschars between males and females with a preponderance of the chest and abdomen among females and the inguinal and axilla in males (Table 1, Figure 1).

Table No 1: Distribution of Eschars (N=39) 

Figure 1: Location of eschar at different sites of body

Scrub typhus is an underappreciated cause of acute febrile illness in many parts of India [8,9]. It is caused by the rickettsial pathogen O. tsutsugamushi, which is transmitted by the bite of larval trombiculid mites inhabiting scrub vegetation. Often, it results in life-threatening complications such as acute respiratory distress syndrome, hepato-renal dysfunction, and meningoencephalitis [10]. The eschar represents the site of inoculation, where initial multiplication occurs before widespread dissemination. An eschar is typically painless and non-pruritic, and hence its presence is not reported by patients. A diligent search for eschar is often rewarding. It clinches a diagnosis of scrub typhus, enabling early initiation of treatment [5,10]

A pathognomonic eschar is a typical feature of scrub typhus and is of high diagnostic value. Presence of eschar is an important finding for the diagnosis of scrub typhus, rickettsialpox, and another mite- or tick-borne rickettsiosis. The presence of eschar in a patient with scrub typhus varies widely in different studies from 9.5% to 86% of patients [5,11,12]. But in the present study, Eschar was present in 39(38.24%) patients. Among these 39 patients 21(53.8%) were males while 18 (46.2%) were females.

In the present study, eschar was most commonly seen in inguinal 9(23.1%), abdomen 7(17.9%), chest (17.9%), axilla 6 (15.4%), lower limbs 4 (10.3%), forearm 3(7.7%), head and neck 2(5.1%) and multiple sites 1(2.6%). There was a significant difference in the distribution of eschars between males and females with a preponderance of the chest and abdomen among females and the inguinal and axilla in males similar to different studies all over the world [5,12,13].A thorough physical examination, especially of the hidden areas such as the genitalia, buttock folds, scalp, and postaural areas, is imperative in identifying this value diagnostic clue of scrub typhus. 

Scrub typhus is endemic and documented zoonosis in the state of Himachal Pradesh as the climatic and geographical conditions are conducive for spread of vector of the scrub typhus. The general practitioners and paediatricians should be sensitised regarding signs, symptoms and risk factors of scrub typhus, so that all cases of febrile illness presenting during this period should be evaluated for this disease.

The pathognomonic eschar of scrub typhus, which is usually found on the genitalia, abdomen, chest, and axillary folds, is one of the most valuable clues in the diagnosis Therefore, the clinicians could early diagnose a scrub typhus if they are aware of the changing form of eschar over time, and would be able to promptly manage the patient with appropriate antibiotics.

1. Luce-Fedrow, A. et al. A Review of Scrub Typhus (Orientia tsutsugamushi and Related Organisms): Then, Now, and Tomorrow. Tropical Medicine and Infectious Disease, vol. 3, no. 8, 2018, pp. 1–30.

2. World Health Organization. WHO Recommended Surveillance Standards. World Health Organization, 1999.

3. Jiang, J., and A. Richards. Scrub Typhus: No Longer Restricted to the Tsutsugamushi Triangle. Tropical Medicine and Infectious Disease, vol. 3, no. 11, March 2018, pp. 1–7.

4. Sharma, A. et al. Investigation of an Outbreak of Scrub Typhus in the Himalayan Region of India. Japanese Journal of Infectious Diseases, vol. 58, no. 4, 2005, pp. 208–210.

5. Kim, D.M. et al. Distribution of Eschars on the Body of Scrub Typhus Patients: A Prospective Study. American Journal of Tropical Medicine and Hygiene, vol. 76, 2007, pp. 806–809.

6. Xu, G. et al. A Review of the Global Epidemiology of Scrub Typhus. PLoS Neglected Tropical Diseases, vol. 11, 2017, e0006062.

7. Rajapakse, S. et al. Scrub Typhus: Pathophysiology, Clinical Manifestations and Prognosis. Asian Pacific Journal of Tropical Medicine, vol. 5, 2012, pp. 261–264.

8. Kamarasu, K. et al. Serological Evidence for Wide Distribution of Spotted Fevers and Typhus Fever in Tamil Nadu. Indian Journal of Medical Research, vol. 126, 2007, pp. 128–130.

9. Mahajan, S.K. et al. Scrub Typhus in Himalayas. Emerging Infectious Diseases, vol. 12, 2006, pp. 1590–1592.

10. Chrispal, A. et al. Scrub Typhus: An Unrecognized Threat in South India—Clinical Profile and Predictors of Mortality. Tropical Doctor, vol. 40, 2010, pp. 129–133.

11. Kumar, K. et al. Outbreak Investigation of Scrub Typhus in Himachal Pradesh (India). Journal of Communicable Diseases, vol. 36, 2004, pp. 277–283.

12. Kundavaram, A.P. et al. Eschar in Scrub Typhus: A Valuable Clue to the Diagnosis. Journal of Postgraduate Medicine, vol. 59, 2013, pp. 177–178.

13. Kim, D.M. et al. Clinical and Laboratory Findings Associated with Severe Scrub Typhus. BMC Infectious Diseases, vol. 10, 2010, p. 108.