Introduction

Scrub typhus or bush typhus caused by Orientia tsutsugamushi is a common, zoonotic disease in South East Asia, and due to rapid urbanization of rural and forested areas, it has become an emerging public health problem in India (Vivekanandan et al., 2010). It commonly presents as fever, headache, inoculation eschar, and lymphadenopathy. In severe forms, pneumonia, myocarditis, azotemia, shock, gastrointestinal bleed, and meningoencephalitis are known to occur. Although available medical literature mentions many of these complications, central nervous system involvement, in the form of acute encephalitis syndrome (AES), has seldom been highlighted (Trickman et al., 1995). Relative unawareness of this type of presentation of scrub typhus makes a prompt diagnosis difficult, resulting in significant morbidity and mortality (Thai et al., 2001).

Case Report

History

A 53-year-old female on immunosuppressive agents for Rheumatoid Arthritis shows a history of fever and signs of encephalopathy for the past 10 days. The patient was evaluated by performing routine investigations (Including investigations for Endemic tropical infections), CSF Analysis, and appropriate Radiological investigations as needed (MRI-Brain).

Course and outcome

The patient was initially diagnosed with Encephalitis and empirically managed with broad-spectrum antibiotics. After Evaluation by Serological and radiological investigations patient was found to have both Scrub Typhus (Scrub Typhus IgM) and CMV (CSF- IgM) with CSF showing lymphocytosis. The patient was then treated with doxycycline and Valganciclovir and had clinical improvement (Improvement in GCS and Neurological symptoms had subsided.

Discussion

Scrub typhus is grossly under-diagnosed in India due to its nonspecific clinical presentation, limited awareness and low index of suspicion among clinicians, and lack of diagnostic facilities (Varghese et al., 2006). The infection manifests clinically as a nonspecific febrile illness often accompanied by headache, myalgia, nausea, vomiting, diarrhea, cough, or breathlessness (Kamarasu et al., 2007). Severity varies from subclinical to severe illness with multiple organ system involvements, which can be severe enough to be fatal unless diagnosed early and treated (Mahajan et al., 2008). 

Cytomegalovirus (CMV) can cause severe disease in profoundly immunocompromised individuals, including colitis, pneumonitis, and less commonly encephalitis (Omashekar et al., 2006).

CNS imaging findings are nonspecific and diagnosis is made by identifying CMV through cerebral spinal fluid analysis (Ittyachen, 2009).

Early initiation of antiviral therapy is key with an overall poor outcome (Sharma et al., 2005; Rvencar et al., 2012; Lyu et al., 2013).

Conclusion

In this case, due to the immunosuppressed state, the patient had CMV Infection. Further analysis also confirmed Scrub typhus infection. The Co-infection of both CMV and Scrub Typhus is uncommon. So a comprehensive evaluation for tropical infections in an immunosuppressed patient is necessary.

Author contribution

Vidhya N, Durga Devi G, Shenbaga Lalitha S, and Swetha N B encouraged and supervised the findings of this work. All authors discussed the results and contributed to the final manuscript.

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.