Acute Febrile Illness and Complications Due to Murine Typhus, Texas, USA

Zeeshan Afzal; Sunand Kallumadanda; Feng Wang; Vagish Hemmige; Daniel Musher


Emerging Infectious Diseases. 2017;23(8):1267-1273. 

In This Article

Abstract and Introduction


Murine typhus occurs relatively commonly in southern Texas, as well as in California. We reviewed records of 90 adults and children in whom murine typhus was diagnosed during a 3-year period in 2 hospitals in southern Texas, USA. Most patients lacked notable comorbidities; all were immunocompetent. Initial signs and symptoms included fever (99%), malaise (82%), headache (77%), fatigue (70%), myalgias (68%), and rash (39%). Complications, often severe, in 28% of patients included bronchiolitis, pneumonia, meningitis, septic shock, cholecystitis, pancreatitis, myositis, and rhabdomyolysis; the last 3 are previously unreported in murine typhus. Low serum albumin and elevated procalcitonin, consistent with bacterial sepsis, were observed in >70% of cases. Rash was more common in children; thrombocytopenia, hyponatremia, elevated hepatic transaminases, and complications were more frequent in adults. Murine typhus should be considered as a diagnostic possibility in cases of acute febrile illness in southern and even in more northern US states.


Murine (endemic) typhus is most frequently recognized as an acute febrile illness, although the clinical manifestations of this infection cover the full spectrum of disease, from asymptomatic infection to fulminant disease and death.[1–5] The causative organism, Rickettsia typhi, is a small, gram-negative, obligate intracellular bacterium. Worldwide, especially in tropical and subtropical areas, the roof rat (Rattus rattus) and Norway rat (Rattus norvegicus) have been the principal reservoirs, with the rat flea, Xenopsylla cheopis, as the principal vector.[2,6]

In the United States, individual murine typhus cases and outbreaks have been reported from suburban areas; in these instances, opossums (Didelphis virginiana) and Rattus spp. have been implicated as the reservoirs, with the cat flea, Ctenocephalides felis, as the principal vector.[2] The incidence of murine typhus declined sharply in the United States after the institution of DDT for control of rat fleas in 1945,[5] but it now appears to be on the rise, especially in southern Texas and California.[2,7,8] We describe 90 murine typhus infections that were diagnosed in 2 hospitals in Hidalgo County, Texas, USA, during a 3-year period, with a comparison of clinical manifestations in adults and children.