Concurrent Scrub Typhus and Cytomegalovirus Encephalitis in an Immunosuppressed Patient: A Rare Case Report

Vidhya N¹, Durga Devi G², Shenbaga Lalitha S³, Swetha N B⁴

This study shows a rare co-infection of scrub typhus and CMV encephalitis in immunosuppressed patients, underscoring diagnostic challenges and treatment strategies.

Abstract

Background: Scrub typhus, a zoonotic infection caused by Orientia tsutsugamushi, is highly endemic in South East Asia and has emerged as a significant public health concern due to increasing urbanization. The disease commonly presents with nonspecific symptoms such as fever, headache, and myalgia, but can lead to severe complications like encephalitis, particularly in immunocompromised patients. Concurrent infections, such as with cytomegalovirus (CMV), are rare but can complicate the clinical presentation and management. Methods: We present a case of a 53-year-old female with rheumatoid arthritis on immunosuppressive therapy who developed encephalitis. The patient was evaluated with a comprehensive diagnostic approach, including cerebrospinal fluid (CSF) analysis, serological testing, and brain imaging. Initial broad-spectrum antimicrobial therapy was started empirically, and further testing was performed to identify potential tropical infections. Results: CSF analysis revealed elevated protein levels and lymphocytic pleocytosis, suggesting a viral or rickettsial etiology. Radiological imaging indicated nonspecific findings of encephalitis. Serological testing confirmed a dual infection with scrub typhus and CMV. The patient’s treatment regimen was adjusted to include doxycycline for scrub typhus and valganciclovir for CMV encephalitis. Following the modified therapy, the patient showed significant clinical improvement, with normalization of her Glasgow Coma Scale (GCS) score and resolution of neurological symptoms. Conclusion: This case highlights the complexity of diagnosing and managing co-infections in immunocompromised patients presenting with encephalitis in endemic regions. It underscores the need for a high index of suspicion for multiple pathogens, comprehensive diagnostic evaluations, and prompt initiation of appropriate therapies to improve patient outcomes. Early recognition of atypical manifestations and co-infections is crucial in reducing morbidity and mortality associated with tropical infections.

Keywords: Scrub typhus, Cytomegalovirus (CMV) infection, Encephalitis, Immunosuppressive therapy, Co-infection

References

Ittyachen, A. M. (2009). Emerging infections in Kerala: A case of scrub typhus. National Medical Journal of India, 22, 333-334.

Kamarasu, K., Malathi, M., Rajagopal, V., Subramani, K., Jagadeeshramasamy, D., & Mathai, E. (2007). Serological evidence for wide distribution of spotted fevers & typhus fever in Tamil Nadu. Indian Journal of Medical Research, 126, 128-130.

Lyu, Y., Tian, L., Zhang, L., Dou, X., Wang, X., Li, W., et al. (2013). A case-control study of risk factors associated with scrub typhus infection in Beijing, China. PLoS One, 8, e63668. https://doi.org/10.1371/journal.pone.0063668

Mahajan, S. K., Rolain, J. M., Sankhyan, N., Kaushal, R. K., & Raoult, D. (2008). Pediatric scrub typhus in Indian Himalayas. Indian Journal of Pediatrics, 75, 947-949. https://doi.org/10.1007/s12098-008-0198-z

Omashekar, H. R., Moses, P. D., Pavithran, S., Mathew, L. G., Agarwal, I., Rolain, J. M., et al. (2006). Magnitude and features of scrub typhus and spotted fever in children in India. Journal of Tropical Pediatrics, 52, 228-229. https://doi.org/10.1093/tropej/fmi096

Rvencar, K. P., Rodrigues, S., Nevrekar, R. P., Dias, L., Dias, A., Vaz, M., et al. (2012). Scrub typhus in patients reporting with acute febrile illness at a tertiary health care institution in Goa. Indian Journal of Medical Research, 136, 1020-1024.

Sharma, A., Mahajan, S., Gupta, M. L., Kanga, A., & Sharma, V. (2005). Investigation of an outbreak of scrub typhus in the Himalayan region of India. Japanese Journal of Infectious Diseases, 58, 208-210.

Thai, E., Lloyd, G., Cherian, T., Abraham, O. C., & Cherian, A. M. (2001). Serological evidence for the continued presence of human rickettsioses in southern India. Annals of Tropical Medicine and Parasitology, 95, 395-398. https://doi.org/10.1080/00034983.2001.11813652

Trickman, D., Sheer, T., Salata, K., Hershey, J., Dasch, G., Kelly, D., et al. (1995). In vitro effectiveness of azithromycin against doxycycline-resistant and -susceptible strains of Rickettsia tsutsugamushi, etiologic agent of scrub typhus. Antimicrobial Agents and Chemotherapy, 39, 2406-2410. https://doi.org/10.1128/AAC.39.11.2406

Varghese, G. M., Abraham, O. C., Mathai, D., Thomas, K., Aaron, R., Kavitha, M. L., et al. (2006). Scrub typhus among hospitalised patients with febrile illness in South India: Magnitude and clinical predictors. Journal of Infection, 52, 56-60. https://doi.org/10.1016/j.jinf.2005.02.001

Vivekanandan, M., Mani, A., Priya, Y. S., Singh, A. P., Jayakumar, S., & Purty, S. (2010). Outbreak of scrub typhus in Pondicherry. Journal of the Association of Physicians of India, 58, 24-28.