A study of peripheral smear findings along with haematological and biochemical parameters in assessing morbidity among seropositive scrub typhus cases at a tertiary care centre: A cross-sectional study.

Dr. R.  Rajakumari; Dr. S. Rajasekhar  Reddy; Dr. C. Sarada  Devi

doi:10.51168/sjhrafrica.v7i2.2713

Authors

Dr. R. Rajakumari Postgraduate, Department of Pathology, S. V. Medical College, Tirupati, Andhra Pradesh, India.
Dr. S. Rajasekhar Reddy Associate Professor, Department of Pathology, S. V. Medical College, Tirupati, Andhra Pradesh, India.
Dr. C. Sarada Devi Assistant Professor, Department of Pathology, S. V. Medical College, Tirupati, Andhra Pradesh, India.

DOI:

https://doi.org/10.51168/sjhrafrica.v7i2.2713

Keywords:

Scrub typhus, peripheral smear, thrombocytopenia, hepatic dysfunction, renal impairment, morbidity predictors

Abstract

Background:

Scrub typhus, caused by Orientia tsutsugamushi, is a re-emerging rickettsial infection characterized by systemic vasculitis and multi-organ involvement. Haematological and biochemical abnormalities are frequently observed and may help in assessing disease morbidity. This study aimed to evaluate peripheral smear findings along with haematological and biochemical parameters in seropositive scrub typhus cases and correlate them with clinical severity.

Methods:

A cross-sectional study was conducted in the Department of Pathology, Sri Venkateswara Ramnarayan Ruia Government General Hospital, Tirupati, over nine months. A total of 45 serologically confirmed scrub typhus cases were included. Complete blood counts were performed using a five-part haematology analyser, ERBA Elite 580. Peripheral blood smears were stained with Leishman stain and examined for morphological changes. Liver and renal function tests were analysed using ERBA XL-640. Associations between laboratory abnormalities and morbidity were assessed using the odds ratio and Fisher’s exact test.

Results:

Most cases occurred between October and December. Males constituted 60% and females 40% of cases. Common haematological abnormalities included thrombocytopenia (66.7%), leucocytosis (35.6%), and neutrophilia with toxic granulation or cytoplasmic vacuolation (31.1%). Biochemical abnormalities included elevated AST (57.8%), ALT (53.3%), hyperbilirubinaemia (40.0%), and raised serum creatinine (20.0%). Severe thrombocytopenia was strongly associated with morbidity (OR 9.75, 95% CI 2.01–47.2; p = 0.001). Significant associations were also observed for elevated transaminases (OR 4.20, 95% CI 1.58–11.1; p = 0.003), hyperbilirubinaemia (OR 3.68, 95% CI 1.22–9.80; p = 0.022), raised serum creatinine (OR 6.10, 95% CI 1.85–20.4; p < 0.001), and neutrophilia with toxic changes (OR 2.95, 95% CI 1.05–8.40; p = 0.020).

Conclusion:

Integrated evaluation of peripheral smear, haematological, and biochemical parameters provides a rapid and cost-effective approach for predicting morbidity in scrub typhus.

Recommendations:

Routine peripheral smear, platelet count, liver, and renal parameters should guide early morbidity assessment in scrub typhus.

Author Biographies

Dr. R. Rajakumari , Postgraduate, Department of Pathology, S. V. Medical College, Tirupati, Andhra Pradesh, India.

MBBS, is a postgraduate in the Department of Pathology, S. V. Medical College, Tirupati, Andhra Pradesh, India. Her academic interests include clinical pathology, haematology, peripheral smear interpretation, infectious disease pathology, and laboratory-based assessment of disease severity. Her present research focuses on evaluating peripheral smear findings along with haematological and biochemical parameters in seropositive scrub typhus cases. Orcid ID: https://orcid.org/0009-0006-7783-7302

Dr. S. Rajasekhar Reddy, Associate Professor, Department of Pathology, S. V. Medical College, Tirupati, Andhra Pradesh, India.

MBBS, MD, is an Associate Professor in the Department of Pathology, S. V. Medical College, Tirupati, Andhra Pradesh, India. He has academic and diagnostic experience in haematology, clinical pathology, and laboratory medicine. His areas of interest include diagnostic haematology, infectious disease-related laboratory abnormalities, and clinicopathological correlation. Orcid ID: https://orcid.org/0009-0004-4603-1985

Dr. C. Sarada Devi , Assistant Professor, Department of Pathology, S. V. Medical College, Tirupati, Andhra Pradesh, India.

MBBS, MD, is an Assistant Professor in the Department of Pathology, S. V. Medical College, Tirupati, Andhra Pradesh, India. Her professional interests include haematology, peripheral smear morphology, clinical pathology, and diagnostic evaluation of infectious and inflammatory disorders. Orcid id: https://orcid.org/0009-0005-3800-0430

References

Vashishtha A, Kumar V, Panwar G, Kausik G, Baig S, Sharma P, Yadav R. Scrub typhus update: A re emerging global threat beyond the Tsutsugamushi Triangle and the physiological ramifications of scrub typhus infection. World Academy of Sciences Journal. 2025 ;7(3):1-14.Doi: https://doi.org/10.3892/wasj.2025.322

Devasagayam E, Dayanand D, Kundu D, Kamath MS, Kirubakaran R, Varghese GM. The burden of scrub typhus in India: A systematic review. PLoS neglected tropical diseases. 2021 ;15(7):e0009619.Doi: https://doi.org/10.1371/journal.pntd.0009619.

Ranjan J, Prakash JA. Scrub typhus re-emergence in India: Contributing factors and way forward. Medical Hypotheses. 2018;115:61-4. Doi: 10.1016/j.mehy.2018.03.019.

Gadekar S, Solanki P, Tiwari A, Rai H, Pandey A, Khan MN, Commander SL, Gupta H. Understanding fever: a practical approach for clinicians. Professional Publication Services; 2024.

Singh SK, Menon A, Kumar S, Khanuja M. Navigating Tropical Monsoon Fevers in India: An Integrated Syndromic and Disease-Specific Approach. Medical Journal of Dr. DY Patil Vidyapeeth. 2026 ;19(1):3-13. Doi: 10.4103/mjdrdypu.mjdrdypu_851_25.

Reddy AM, Iqbal M, Chopra H, Urmi S, Junapudi S, Bibi S, Gupta SK, Pangi VN, Singh I, Abdel-Daim MM. Pivotal role of vitamin D in mitochondrial health, cardiac function, and human reproduction. EXCLI Journal. 2022;21:967. doi: 10.17179/excli2022-4935

Sharma M, Gupta S, Tripathi D, Verma SK, Sharma L, Gupta P, Sharma KR, Sahi N. Clinical and biochemical profile of scrub typhus patients with emphasis on liver dysfunction in a tertiary care centre in South Rajasthan. Int J Res Med Sci. 2024 ;12:2814-20. Doi: https://doi.org/10.18203/2320-6012.ijrms20241960

Gungam P, Yadav YS, Junapudi S. Antibiotic use in pediatric infections: a study in a tertiary care hospital. International Journal of Clinical and Biomedical Research. 2018:26-32.

Varghese GM, Abraham OC, Mathai D, Thomas K, Aaron R, Kavitha ML, Mathai E. Scrub typhus among hospitalised patients with febrile illness in South India: magnitude and clinical predictors. Journal of Infection. 2006 ;52(1):56-60. Doi: https://doi.org/10.1016/j.jinf.2005.02.001

Kumar R, Sharma I, Goyal K, Khujwal MM. Clinical and biochemical profile in patients of scrub typhus: an under-reported disease, a tertiary care hospital-based study in Uttarakhand, India. International Journal of Research in Medical Sciences. 2024 ;12(1):70.Doi: DOI: https://dx.doi.org/10.18203/2320-6012.ijrms20233836 .

Vivekanandan M, Mani A, Priya YS, Singh AP, Jayakumar S, Purty S. Outbreak of scrub typhus in Pondicherry. J Assoc Physicians India. 2010;58(1):24-8.

Itani Y, Moriyama Y, Ewers E, Samaha D, Drew B, Kotler JA, Nagata T, Hughey S. Tropical Diseases in Okinawa: Overview and Emerging Infectious Diseases. Wilderness & Environmental Medicine. 2025 ;36(1):19-26. Doi: https://doi.org/10.1177/10806032241249995.

Kala D, Gupta S, Nagraik R, Verma V, Thakur A, Kaushal A. Diagnosis of scrub typhus: recent advancements and challenges. 3 Biotech. 2020 ;10(9):396. Doi:https://doi.org/10.1007/s13205-020-02389-w

Hazarika B, Khanna N, Bain BJ. Hematological features of scrub typhus. American Journal of Hematology. 2023 ;98(12):1951-2. https://doi.org/10.1002/ajh.27078.

Jantikar A. A study of various biochemical parameters in patients with scrub typhus. Panacea J Med Sci. 2021;11(1):72-6. Doi: https://doi.org/10.18231/j.pjms.2021.017.

Kelly DJ, Fuerst PA, Ching WM, Richards AL. Scrub typhus: the geographic distribution of phenotypic and genotypic variants of Orientia tsutsugamushi. Clinical infectious diseases. 2009 ;48(3):S203-30.Doi: https://doi.org/10.1086/596576

Mahajan SK, Mahajan SK. Neuropsychiatric manifestations of scrub typhus. Journal of Neurosciences in Rural Practice. 2017;8(3):421. doi: 10.4103/jnrp.jnrp_44_17.

Gautam R, Parajuli K, Sherchand JB. Epidemiology, risk factors, and seasonal variation of scrub typhus fever in Central Nepal. Tropical medicine and infectious disease. 2019 ;4(1):27.Doi: https://doi.org/10.3390/tropicalmed4010027

Kim J, Vounatsou P, Chun BC. Distribution and risk factors of scrub typhus in South Korea, from 2013 to 2019: Bayesian spatiotemporal analysis. JMIR Public Health and Surveillance. 2025 ;11(1):e68437.doi: 10.2196/68437