Abducens nerve palsy and meningitis by Rickettsia typhi

Severe murine typhus complicated by multiple organ dysfunctions: A case report

Background

Rickettsioses are infectious diseases which are caused by intracellular bacteria which belong to the family Rickettsiaceae. This zoonosis endemically prefers tropical and subtropical regions of which the Mediterranean is included. Murine typhus is a type of rickettsial disease that commonly presents with undulating fever, headache rash, chills, malaise, and myalgias. It can lead to complications such as multi-organ failure and has a lethality rate of <5% in such cases.

Case Presentation

A 70-year-old male was hospitalized at the Unit of Infectious Diseases, Mother Teresa Hospital, Tirana, Albania in a comatose condition. He had a seven-day history of fever up to 39-40°C, headache, fatigue, anorexia, vomiting, cough, and myalgia. He was a farmer and had contact with animals. Upon admission, he had scleral hemorrhages, hepatosplenomegaly, jaundice, maculopapular rash over the trunk, abdomen, and palms of his hands as well as severe acidosis, depressed bicarbonate levels, alteration in liver, kidney, and pancreas function tests. He was urgently transferred to the Intensive care unit of the Infectious Diseases Department. He was hemodynamically unstable and was put immediately on vasoactive agents and mechanical ventilation. ELISA Rickettsia typhi IgM resulted positive. Supportive treatment along with antibiotics Levofloxacin and Ceftriaxone was initiated. However, the patient died on the 4th day of hospitalization and the 11th of the disease onset.

Conclusion

Murine typhus should be included in the investigation of possible causes when dealing with patients presenting with fever and maculopapular rash complicated by multi-organ failure and coming from a typhus-endemic area, especially in the summer season.

Murine Typhus: A Review of a Reemerging Flea-Borne Rickettsiosis with Potential for Neurologic Manifestations and Sequalae

Murine typhus is an acute febrile illness caused by Rickettsia typhi, an obligately intracellular Gram-negative coccobacillus. Rats (Rattus species) and their fleas (Xenopsylla cheopis) serve as the reservoir and vector of R. typhi, respectively. Humans become infected when R. typhi-infected flea feces are rubbed into flea bite wounds or onto mucous membranes. The disease is endemic throughout much of the world, especially in tropical and subtropical seaboard regions where rats are common. Murine typhus is reemerging as an important cause of febrile illness in Texas and Southern California, where an alternate transmission cycle likely involves opossums (Didelphis virginiana) and cat fleas (Ctenocephalides felis). Although primarily an undifferentiated febrile illness, a range of neurologic manifestations may occur, especially when treatment is delayed. Serology is the mainstay of diagnostic testing, but confirmation usually requires demonstrating seroconversion or a fourfold increase in antibody titer from acute- and convalescent-phase sera (antibodies are seldom detectable in the first week of illness). Thus, early empiric treatment with doxycycline, the drug of choice, is imperative. The purpose of this review is to highlight murine typhus as an important emerging and reemerging infectious disease, review its neurologic manifestations, and discuss areas in need of further study.

Delayed correlation between the incidence rate of indigenous murine typhus in humans and the seropositive rate of Rickettsia typhi infection in small mammals in Taiwan from 2007–2019

Murine typhus is a flea-borne zoonotic disease with acute febrile illness caused by Rickettsia typhi and is distributed widely throughout the world, particularly in port cities and coastal regions. We observed that murine typhus was an endemic disease (number of annual indigenous cases = 29.23±8.76) with a low incidence rate (0.13±2.03*10⁻⁴ per 100,000 person-years) in Taiwan from 2007–2019. Most (45.79%, 174/380) indigenous infections were reported in May, June, and July. The incidence rates in both May and June were statistically higher than those in other months (p<0.05). Correspondingly, sera collected from small mammals (rodents and shrews) trapped in airports and harbors demonstrated anti-R. typhi antibody responses (seropositive rate = 8.24±0.33%). Interestingly, the ports with the highest seropositivity rates in small mammals are all inside/near the areas with the highest incidence rates of indigenous murine typhus. In addition, incidence rates in humans were positively correlated with the 1-month and 2-month prior seropositive rates in small mammals (R = 0.31 and 0.37, respectively). As early treatment with appropriate antibiotics for murine typhus could effectively shorten the duration of illness and reduce the risk of hospitalization and fatality, flea-related exposure experience should be considered in clinics during peak seasons and the months after a rise in seropositivity rates in small mammals. Surveillance in small mammals might be helpful for the development of real-time reporting or even early reminders for physicians of sporadic murine typhus cases based on the delayed correlation observed in this study.

Murine typhus is a flea-borne zoonotic disease with acute febrile illness caused by Rickettsia typhi and is distributed widely throughout the world, particularly in port cities and coastal regions. Early treatment with appropriate antibiotics for murine typhus could effectively shorten the duration of illness and reduce the risk of hospitalization and fatality. However, it presents with nonspecific symptoms and is oftentimes misdiagnosed. In Taiwan, murine typhus has been designated a notifiable disease since 2007. Meanwhile, surveillance of R. typhi infection of small mammals was also launched at 25 international airports and harbors. Since then, we observed that indigenous murine typhus patients have been detected in Taiwan annually and sera collected from small mammals trapped in ports also demonstrated anti-R. typhi antibody responses. Correspondingly, the ports with the highest seropositivity are all inside/near the areas with the highest incidence rate of indigenous murine typhus in Taiwan. We further found that incidence rates in humans were positively correlated with the 1-month and 2-month prior seropositive rates in small mammals. Surveillance in small mammals might be helpful for the development of real-time reporting or even early reminders of sporadic murine typhus cases based on the delayed correlation observed in this study.

Profile of Neurological Manifestations in Children Presenting With Rickettsial Disease

Objective

To study the profile of neurological manifestation of rickettsial disease in children.

Methods

Review of hospital records was done in a tertiary care hospital for the period from January to December, 2020. Data of all the children fulfilling the inclusion criteria i.e., clinical criteria and serology were retrieved from the hospital records.

Results

Of the total 7974 children admitted over this period, 178 were diagnosed with rickettsial disease wherein 54 (33.3%) had neurological involvement. Convulsions (59%), altered sensorium (56%), headache (44%), meningeal signs (37%), ataxia, (11%), lateral rectus palsy (7.5%) and stroke (7.5%) were the major neurological manifestations. Cerebrospinal fluid (CSF) analysis done in 30 (55%) children showed pleocytosis [median (IQR) cells 15 (3.75, 50)] with lymphocyte predominance [median (IQR) lymphocytes 11.5 (3, 38.75)] and elevated proteins [median IQR 41.5 (29.75,61)]. Neuroimaging abnormalities noticed were cerebral edema (n=7), cerebellar hyperintensities (n=5), basal ganglia infarcts (n=2) and hippocampal hyperintensities (n=1).

Conclusion

Early recognition of rickettsial infection as a cause of neurological manifestation would facilitate early specific management.

Abducens nerve palsy with associated retinal involvement secondary to rickettsia typhi infection

OBJECTIVE

To report a case of abducens nerve palsy with associated retinal involvement due to rickettsia typhi infection.

MATERIAL AND METHODS

A single case report documented with multimodal imaging.

RESULTS

A 18-year-old woman with a history of high-grade fever was initially diagnosed with typhoid fever and treated with fluoroquinolone. She presented with a 5-day history of diplopia and headaches. Her best-corrected visual acuity was 20/20 in both eyes. Ocular motility examination showed left lateral gaze restriction. Lancaster test confirmed the presence of left abducens palsy. Fundus examination showed optic disc swelling in both eyes associated with superotemporal retinal hemorrhage and a small retinal infiltrate with retinal hemorrhage in the nasal periphery in the left eye. Magnetic resonance imaging (MRI) of the brain and orbits showed no abnormalities. A diagnosis of rickettsial disease was suspected and the serologic test for Richettsia Typhi was positive. The patient was treated with doxycycline (100 mg every 12 h) for 15 days with complete recovery of the left lateral rectus motility and resolution of optic disc swelling, retinal hemorrhages, and retinal infiltrate.

CONCLUSION

Rickettsial disease should be considered in the differential diagnosis of abducens nerve palsy in any patient with unexplained fever from endemic area. Fundus examination may help establish an early diagnosis and to start an appropriate rickettsial treatment.

The temporal dynamics of humoral immunity to Rickettsia typhi infection in murine typhus patients

OBJECTIVES

This study examined individuals with Rickettsia typhi infection in the Lao People's Democratic Republic (Lao PDR) to (a) investigate humoral immune dynamics; (b) determine the differences in reference diagnostic results and recommend appropriate cut-offs; (c) determine differences in immune response after different antibiotic treatments; and (d) determine appropriate diagnostic cut-off parameters for indirect immunofluorescence assay (IFA).

METHODS

Sequential serum samples from 90 non-pregnant, adults were collected at seven time-points (days 0, 7, 14, 28, 90, 180 and 365) as part of a clinical antibiotic treatment trial. Samples were tested using IFA to determine IgM and IgG antibody reciprocal end-point titres against R. typhi and PCR.

RESULTS

For all 90 individuals, reciprocal R. typhi IgM and IgG antibody titres ranged from <400 to ≥3200. The median half-life of R. typhi IgM was 126 days (interquartile range 36-204 days) and IgG was 177 days (interquartile range 134-355 days). Overall median patient titres for R. typhi IgM and IgG were significantly different (p < 0.0001) and at each temporal sample collection point (range p < 0.0001 to p 0.0411). Using Bayesian latent class model analysis, the optimal diagnostic cut-off reciprocal IFA titer on patient admission for IgM was 800 (78.6%, 95% CI 71.6%-85.2% sensitivity; 89.9%, 95% CI 62.5%-100% specificity), and for IFA IgG 1600 (77.3%; 95% CI 68.2%-87.6% sensitivity; 99%, 95% CI 95%-100% specificity).

CONCLUSIONS

This study suggests suitable diagnostic cut-offs for local diagnostic laboratories and other endemic settings and highlights antibody persistence following acute infection. Further studies are required to validate and define cut-offs in other geographically diverse locations.

Rickettsial infections of the central nervous system

As a result of migrations and globalization, people may face a possible increase in the incidence of central nervous system rickettsial infections (CNS R). These diseases, caused by Rickettsia species and transmitted to humans by arthropod bites, are putatively lethal. However, the diagnosis of CNS R is challenging and often delayed due to their nonspecific clinical presentation and the strict intracellular nature of rickettsiae. Furthermore, transfer of rickettsiae to the brain parenchyma is not yet understood. The aim of this review is to analyze and summarize the features and correlated findings of CNS R in order to focus attention on these intriguing but frequently neglected illnesses. We also incorporated data on CNS infections caused by Rickettsia-related microorganisms.

Murine typhus presenting with status epilepticus

Patients with rickettsial infection usually present with a febrile illness, headache, arthromyalgia and various biochemical abnormalities. Neurologic involvement is rare in murine typhus. Here, we report a case of a patient who presented with status epilepticus secondary to Rickettsia typhi infection.

Intra-aural tick bite causing unilateral facial nerve palsy in 29 cases over 16 years in Kandy, Sri Lanka: is rickettsial aetiology possible?

Background

Over the last two decades intra-aural tick infestation (otoacariasis) has been a common occurrence in the hilly central region in Sri Lanka. Very occasional detection of isolated unilateral facial nerve palsy associated with otoacariasis attributed to toxin damage of the nerve prompted us to study the clinico-epidemiology and aetio-pathology of the problem.

Methods

All cases having isolated unilateral facial nerve palsy associated with otoacariasis presented to, Ear Nose and Throat clinic at General Hospital Kandy, Sri Lanka from 2001 to 2016 were included in the study. The facial palsies were assessed with nerve conduction studies and, harvested ticks were identified.

Results

There were 29 patients with mean age of 46 years (range 22–76 years) with male to female ratio of 1:1.9. First 12 patients without specific treatment took 1–55 months for recovery and 4 had axonal degeneration. Last 5 patients were treated with doxycycline and recovered in 4 weeks. They had strong sero-conversion of immunofluorescence antibodies against spotted fever rickettsioses and the tick harvested from the last patient was PCR positive for rickettsial DNA. Identified ticks belonged to Dermacentor, Amblyomma, Rhipicephalus and Hyalomma species.

Conclusions

On contrary to popular toxin theory, we were able to demonstrate treatable rickettsial aetio-pathology as the cause of otoacariasis associated lower motor facial palsy in Sri Lanka.

Case of Rickettsia typhi-induced Brain Abscess Mimicking Brain Tumor

Murine typhus is one of the most prevalent rickettsial infections in the world, caused by the bacterial genus Rickettsia. Though the disease manifests a relatively benign clinical course with fever, rash, and headache being the 3 classic symptoms, neurological complications may arise in patients that could become permanent. In this case study, a patient with a brain abscess caused by R typhi infection is described. Based upon the recent reemergence of arthropod-borne disease, the findings in this case are significant; R typhi can cause a brain abscess that mimics a brain tumor, which delays the diagnosis and appropriate management of the disease. Murine typhus should always be considered when performing the differential diagnosis of brain abscesses in South Korea.

Case Report: Fulminant Murine Typhus Presenting with Status Epilepticus and Multi-Organ Failure: an Autopsy Case and a Review of the Neurologic Presentations of Murine Typhus

Murine typhus (MT) is an important cause of febrile illness in endemic areas, and there is an epidemiologic resurgence of this infection currently transpiring in Texas and California. Fatal cases and severe neurological complications are rare. A fatal case of MT in a middle-aged man is reported with a course culminating in multi-organ failure and refractory status epilepticus. An autopsy revealed hemorrhagic pneumonia, acute tubular necrosis, and ischemic necrosis in the liver, adrenals, and brain. We have also reviewed the neurologic complications of MT.

Persisting Rickettsia typhi Causes Fatal Central Nervous System Inflammation

Rickettsioses are emerging febrile diseases caused by obligate intracellular bacteria belonging to the family Rickettsiaceae. Rickettsia typhi belongs to the typhus group (TG) of this family and is the causative agent of endemic typhus, a disease that can be fatal. In the present study, we analyzed the course of R. typhi infection in C57BL/6 RAG1(-/-) mice. Although these mice lack adaptive immunity, they developed only mild and temporary symptoms of disease and survived R. typhi infection for a long period of time. To our surprise, 3 to 4 months after infection, C57BL/6 RAG1(-/-) mice suddenly developed lethal neurological disorders. Analysis of these mice at the time of death revealed high bacterial loads, predominantly in the brain. This was accompanied by a massive expansion of microglia and by neuronal cell death. Furthermore, high numbers of infiltrating CD11b(+) macrophages were detectable in the brain. In contrast to the microglia, these cells harbored R. typhi and showed an inflammatory phenotype, as indicated by inducible nitric oxide synthase (iNOS) expression, which was not observed in the periphery. Having shown that R. typhi persists in immunocompromised mice, we finally asked whether the bacteria are also able to persist in resistant C57BL/6 and BALB/c wild-type mice. Indeed, R. typhi could be recultivated from lung, spleen, and brain tissues from both strains even up to 1 year after infection. This is the first report demonstrating persistence and reappearance of R. typhi, mainly restricted to the central nervous system in immunocompromised mice.