Sea-fan retinal neovascularization associated with rickettsial retinitis: a case report.

BACKGROUND: Rickettsial disease has been commonly associated with retinitis, retinal vasculitis, and optic nerve involvement, but the development of retinal neovascularization has been very rarely reported. We herein describe a case of rickettsial retinitis complicated with the development of sea-fan retinal neovascularization documented with multimodal imaging, including fundus photography, SS-OCT, fluorescein angiography, and SS-OCT angiography. CASE PRESENTATION: A 26-year-old female with a history of fever one week earlier presented with sudden decreased vision in the left eye. Best-corrected visual acuity (BCVA) was 20/2000 and the patient was diagnosed with rickettsial retinitis along the superotemporal retinal vascular arcade associated with serous retinal detachment and retinal hard exudates. The indirect immunofluorescence test was positive for Rickettsia conorii, and the patient was treated with oral doxycycline (200 mg/day) and oral prednisone (0.75 mg/kg/day, with gradual tapering). Four weeks after presentation, the retinal infiltrate and associated serous retinal detachment had resolved, but retinal hard exudates had increased. A large sea-fan preretinal fibrovascular neovascularization became apparent along the superotemporal retinal vascular arcade, but there was no associated retinal ischemia on fluorescein angiography. The patient received an adjunctive single intravitreal injection of 1.25 bevacizumab. Sequential follow-up examinations showed shrinking of sea-fan retinal neovascularization, a complete resolution of retinal hard exudates, and the development of a self-limited vitreous hemorrhage. On last follow-up, 30 months after intravitreal bevacizumab injection, BCVA was 20/25. CONCLUSION: Patients with rickettsial retinitis may develop a sea-fan retinal neovascularization, with subsequent vitreous hemorrhage, putatively through inflammatory mechanisms. Multimodal imaging including OCT, fluorescein angiography, and OCT-angiography, is highly useful for accurate diagnosis and reliable monitoring of the evolution of retinitis, retinal neovascularization, and other retinal changes. The use of a combination therapy with oral doxycycline and corticosteroids and intravitreal anti-VEGF can improve outcomes.

[Fever and a papule after a visit to a South-African Wild Park]. / Koorts en papel na bezoek aan Zuid-Afrikaans wildpark.

A 39-year old man presented in our emergency room with fever, lymphadenopathy in his right groin and a red papule with a dark center. He was treated with doxycycline and recovered well. Serology showed Rickettsia africae with seroconversion after a few weeks.

Síntomas gastrointestinales, disfunción respiratoria, hepática y renal, principales factores asociados a letalidad por rickettsiosis trasmitida por garrapatas en Mexicali, Baja California, México / Gastrointestinal symptoms, respiratory, hepatic and renal dysfunction, main factors associated with lethality due to tickborne rickettsiosis in Mexicali, Baja California, Mexico

INTRODUCCIÓN: La rickettsiosis, enfermedad potencialmente mortal, es trasmitida por vectores como Rhipicephalus sanguineus, Dermacentor variabilis y D. andersonii, reservorios de Rickettsia rickettsii. En Baja California, México, es endémica, multifactorial, tiene alta letalidad, sus manifestaciones clínicas inespecíficas y ataque multisistémico dificultan el diagnóstico y tratamiento oportuno. OBJETIVO: Identificar los factores de riesgo asociados a la letalidad por rickettsiosis trasmitida por garrapatas en Mexicali, Baja California. PACIENTES Y MÉTODOS : Estudio observacional, analítico, transversal, retrospectivo, de 40 registros de pacientes con diagnóstico confirmado de rickettsiosis, periodo 2014 a 2018. Variables analizadas: sociodemográficas, clínicas, laboratorio clínico, evolución y desenlace. Se reportan frecuencias y medidas de asociación. RESULTADOS: 24 defunciones y 16 vivos. Más de 90% tuvo contacto conocido con garrapatas. Afectó en su mayoría a < 45 años en ambos grupos. La evolución antes del ingreso fue similar y la estancia hospitalaria fue mayor en los pacientes vivos (3,2 ± 4.7 vs 10,62 ± 7,6 p = 0,0002). Fiebre, cefalea, mialgias fueron predominantes. Datos asociados con letalidad: disfunción respiratoria (OR 38,33 IC95% 4,06-361,3 p < 0,0001), creatinina elevada (OR 15,4 IC95% 3,08-76,77 p < 0,0003), retardo del llenado capilar (OR 13,0 IC95% 2,73-61,78 p = 0,0005), dolor abdominal (OR 8,33, IC95% 1,90-36,44 p = 0,0029), AST (OR 7,5, IC95% 1,69-33,27 p = 0,005). CONCLUSIÓN: Esta enfermedad requiere de identificación temprana de factores que se asocian con letalidad para un tratamiento oportuno y adecuado.

BACKGROUND: Rickettsiosis, a potentially fatal disease, is transmitted by vectors such as Rhipicephalus sanguineus, Dermacentor variabilis and D. andersonii, reservoirs of Rickettsia rickettsii. In Baja California, Mexico, it is endemic, multifactorial, has high lethality, its nonspecific clinical manifestations and multisystem attack make diagnosis and timely treatment difficult. AIM: Identify the risk factors associated with lethality due to tick-transmitted rickettsiosis in Mexicali, Baja California. METHODS: Observational, analytical, cross-sectional, retrospective study of 40 records of patients with a confirmed diagnosis of rickettsiosis, period 2014 to 2018. Analyzed variables: sociodemographic, clinical, clinical laboratory, evolution and outcome. Frequencies and association measures are reported. RESULTS: 24 patients died and 16 survived. More than 90% had reported contact with ticks. It mostly affected ≤ 45 years in both groups. The evolution before admission was similar, and the hospital stay was longer in patients who lived (3.2 ± 4.7 vs 10.62 ± 7.6 p = 0.0002). Fever, headache, and myalgia are predominant. Data associated with lethality: respiratory dysfunction (OR 38.33 95% CI 4.06-361.3 p < 0.0001), elevated creatinine (OR 15.4 95% CI 3.08-76.77 p < 0.0003), delayed capillary refill (OR 13.0, 95% CI 2.73-61.78 p = 0.0005), abdominal pain (OR 8.33, 95% CI 1.90-36.44 p = 0.0029), AST (OR 7.5, 95% CI 1.69-33.27 p = 0.005). CONCLUSION: This disease requires early identification of factors that are associated with lethality for timely and adequate treatment.

Case Report: Fatal Rickettsiosis in Pregnancy.

Rocky Mountain spotted fever (RMSF) is a tick-borne infection caused by Rickettsia rickettsii. We present a series of two cases of pregnant patients who showed up at the emergency room of a hospital in Nuevo León, Mexico. Both patients lived in environments where R. rickettsii is endemic and they presented with several days of symptoms, including fever. Both patients developed a rash and had stillbirths during their hospital stay. Treatment with doxycycline was delayed, with fatal results in both patients. Diagnosis of RMSF was confirmed via polymerase chain reaction assay postmortem. The need to link epidemiological clues with clinical data is critical in the diagnosis and early treatment of RMSF to prevent maternal deaths.

Scalp eschar and neck lymph adenopathy after a tick bite (SENLAT) in Tuscany, Italy (2015-2022).

INTRODUCTION: The Scalp Eschar and Neck Lymph Adenopathy After a Tick Bite (SENLAT) syndrome is frequently caused by Rickettsia slovaca and Rickettsia raoultii. Only six microbiologically confirmed SENLAT cases have been reported in Italy between 1996 and 2021. We report ten cases of SENLAT seen between 2015 and 2022 in a tertiary care center in Tuscany, Italy. CASES PRESENTATION: All patients were women; most common symptoms were scalp eschar on the site of tick bite (100%) and cervical lymphadenopathy (90%). No microbiological identification was obtained. Persistent alopecia, for several months to years, was observed in four patients. The known difficulty of microbiological diagnosis in SENLAT was worsened, in our cases, by factors as the absence of ticks available for identification and microbiological study, and antibiotic treatment administration previous to microbiological tests. CONCLUSION: The report highlights the presence of SENLAT in Italy, aiming to raise the awareness toward the emergence of this clinical entity.

[Autochthonous Rickettsia parkeri rickettsiosis in the Paranaense Forest, Misiones, Argentina]. / Caso autóctono de rickettsiosis por Rickettsia parkeri en la Selva Paranaense, Misiones, Argentina.

We report an autochthonous case of Rickettsia parkeri rickettsiosis occurred in June 2018 in a forested area of the Urugua-í Provincial Park, Misiones, Argentina. No previous records of this disease in humans have been previously reported in this region. The epidemiological, ecological, clinical, and laboratory features required for a proper diagnosis and adequate treatment are described here. The fact of considering rickettsiosis as a differential diagnosis in a patient with exanthematic acute febrile syndrome is highlighted, being the epidemiological history of exposure to the vector (ticks of the genus Amblyomma) an essential element.

When a travel bug gets you down: severe, hypotensive African tick bite fever and response to therapy.

African tick bite fever, resulting from Rickettsia africae inoculation, is endemic in sub-Saharan Africa. We present a United States traveler with African tick bite fever 5 days after she returned from a mission trip to Zimbabwe. The patient exhibited symptomatic hypotension in addition to more typical findings, including fever, fatigue, and a necrotic eschar. The diagnosis was supported by histopathological findings and the patient's symptoms rapidly resolved with oral doxycycline therapy. We believe this case represents the first African tick bite fever diagnosis associated with symptomatic hypotension. This case additionally serves as a reminder of the importance of evaluating patient travel history.

Emerging Spotted Fever Rickettsioses in the United States.

Spotted fever rickettsioses are important causes of emerging infectious disease in the United States and elsewhere. Rocky Mountain Spotted Fever, caused by R. rickettsii causes a febrile, acute illness in dogs. Because it circulates in peripheral blood in low copy number and because of the acute nature of the disease, dogs may test PCR and seronegative at the time of presentation. Therefore, therapy with doxycycline must be initiated and continued based on the clinician's index of suspicion. Combining PCR with serologic testing, repeat testing of the same pre-antimicrobial blood sample, and testing convalescent samples for seroconversion facilitates diagnosis. The prognosis can be excellent if appropriate antimicrobial therapy is begun in a timely fashion. It is well established that dogs are sentinels for infection in people in households and communities. Whether R. rickettsii causes illness in cats is not well established. The role of other spotted fever group rickettsia in causing illness in dogs and cats is being elucidated. Veterinarians should keep in mind that novel and well characterized species of SFG Rickettsia are important causes of emerging infectious disease. Veterinarians can play an important role in detecting, defining, and preventing illness in their canine patients and their human companions.

Rare Case of Rickettsiosis Caused by Rickettsia monacensis, Portugal, 2021.

We report a case of rickettsiosis caused by Rickettsia monacensis in an immunocompetent 67-year-old man in Portugal who had eschar, erythematous rash, and an attached Ixodes ricinus tick. Seroconversion and eschar biopsy led to confirmed diagnosis by PCR. Physicians should be aware of this rare rickettsiosis, especially in geographic regions with the vector.

Rickettsial illnesses, a leading cause of acute febrile illness.

Rickettsial illnesses, comprising mainly spotted fever group, typhus group and scrub typhus, are vector-borne re-emerging or newly emerging febrile illnesses where humans are an accidental dead-end host. They are a major cause of non-malarial febrile illnesses among returned travellers. They commonly present as an acute febrile illness and carry a characteristic entry wound (eschar) or a discrete erythematous maculo-popular rash based on the organism and the region. The illness severity is mainly dependent on the virulence of the rickettsial organism and delay in the diagnosis is known to cause severe illness with multi-organ involvement carrying high mortality. Almost all rickettsial infections respond to anti-rickettsial antibiotics such as doxycycline within 48-72 hours. Awareness of rickettsial illnesses and their various clinical presentations helps in early diagnosis and institution of appropriate treatment and hence prevent morbidity and mortality.

Revisiting the Overlooked Infection: Rickettsioses.

The prevalence of human Rickettsioses cases in Indonesia is unknown and could probably be underestimated. The high prevalence of seropositive Rickettsia sp. was reported in small mammals (as vectors) and humans. In Indonesia, a recent study in patients with acute fever revealed that the prevalence of Rickettsioses is 10%. Many cases of Rickettsioses were often misdiagnosed with dengue fever, enteric fever, or leptospirosis due to their overlapping clinical manifestation. The limitation of point of care testing in Indonesia hindered the adequacy of diagnosis confirmation. Appropriate empirical or definitive treatment with macrolide, mainly doxycycline, is preferable compared to other broad-spectrum antibiotics, such as cephalosporin or quinolones. Moreover, when left untreated, Rickettsioses may deteriorate progressively to fatal outcomes, such as meningitis, sepsis, and even death. The awareness of health care practitioners, the availability of confirmatory rapid diagnostic tests and adequate treatment choices are important in eradicating this disease.

Rickettsiosis subcommittee report to the tick-borne disease working group.

Tick-borne rickettsial infections are serious, common, and difficult to diagnose. Among the most important factors leading to failure to diagnose and treat tick-borne rickettsioses effectively is a lack of consideration of the potential diagnosis by primary caregivers and emergency department physicians in patients presenting with undifferentiated acute febrile illness during tick season. This situation exists because of insufficient primary and continuing medical education of medical students, primary care and emergency medicine residents, and practicing physicians regarding tick-borne rickettsioses specific to the region where they practice. Delayed initiation of treatment with an appropriate antibiotic is associated with adverse outcomes including increased rates of hospitalization, admission to an intensive care unit, and mortality. The earliest symptoms are nonspecific, consisting of fever, headache, myalgias, and nausea and/or vomiting. Laboratory abnormalities are typically absent at this time when the therapeutic response to an appropriate antibiotic would be optimal. There is a mistaken idea among a substantial portion of physicians that the best antibiotic available, doxycycline, should not be administered to children 8 years of age or younger or during pregnancy. For all of the above reasons, there is unnecessary morbidity and mortality caused by tick-borne rickettsioses. This report proposes measures to address these critical issues regarding tick-borne rickettsioses.

A tick bite patient with fever and meningitis co-infected with Rickettsia raoultii and Tacheng tick virus 1: a case report.

BACKGROUND: Increasing numbers of tick-borne pathogens are being discovered, including those that infect humans. However, reports on co-infections caused by two or more tick-borne pathogens are scarce. CASE PRESENTATION: A 38-year-old male farmer was bitten by a hard tick, presented with fever (37.7 °C), severe headache and ejection vomiting. Lumbar puncture was performed in the lateral decubitus. The cerebrospinal fluid (CSF) was clear, and analysis showed severe increased pressure (320 mm H2O), mild leukocytosis (126.0 × 106/L, mononuclear cells accounting for 73%) and elevated total protein concentration (0.92 g/L). Bacterial cultures of CSF and blood were negative. The diagnosis of Rickettsia raoultii and Tacheng tick virus 1 (TcTV-1) co-infection was confirmed by amplifying four rickettsial genetic markers and the partial small (S) RNA segment of TcTV-1 from the patient's blood. The patient gradually recovered after treatment with levofloxacin and ribavirin. CONCLUSIONS: This is the first reported co-infection case with fever and meningitis caused by R. raoultii and TcTV-1. It is vital to screen for multiple pathogens in tick-bitten patients, especially in those with severe complex symptoms.

Recognition and treatment of devastating vasculopathic systemic disorders: Coronavirus disease 2019 and rickettsioses.

Cutaneous involvement can be an important sign of both COVID-19 and rickettsioses. Rickettsial infections may be first evident as an exanthem with eschars as a key finding. In contrast, eschars and necrotic lesions can be seen in critically ill COVID-19 patients. Both illnesses share a similar mechanism of infecting endothelial cells resulting in vasculopathy. Rickettsia parkeri and Rickettsia 364D are both characterized by eschars unlike Rickettsia rickettsii. Other eschar causing rickettsioses such as Rickettsia conorii, Rickettsia africae, and Orientia tsutsugamushi are commonly diagnosed in people from or having traveled through endemic areas. While there is no consensus on treatment for COVID-19, rickettsioses are treatable. Due to possibly serious consequences of delayed treatment, doxycycline should be administered given an eschar-presenting patient's travel history and sufficient suspicion of vector exposure. The proliferation of COVID-19 cases has rendered it critical to differentiate between the two, both of which may have overlapping vasculopathic cutaneous findings. We review these diseases, emphasizing the importance of cutaneous involvement, while also discussing possible therapeutic interventions.

Lymphangitis-Associated Rickettsiosis by Rickettsia sibirica mongolitimonae.

Rickettsia sibirica mongolitimonae is considered a rare pathogen that can cause different clinical presentations. Approximately, one-third of the patients with this infection experience lymphangitis from the inoculation eschar to the draining lymph nodes, and, in that case, the infection is named "lymphangitis-associated rickettsiosis" (LAR). There are several reports of infections by this Rickettsia but none of LAR in children. We report a case of LAR in a Spanish child, which confirms the distribution of this agent in our country, and his implication in pediatric population.

[Severe encephalitis caused by infection of Rickettsia felis: a case report].

Rickettsia felis is a Gram-negative prokaryotic organism that is obligatorically parasitic in cells. Cat fleas are the main vector of Rickettsia felis. Clinical symptoms of human infection with Rickettsia felis include fever, fatigue, headache, macular papules, and eschar. There are few reports of serious complications or deaths due to infection of Rickettsia felis. A confirmed case of severe encephalitis caused by Rickettsia felis infection was admitted to neurology department of Affiliated Hospital of Jining Medical University on January 29, 2020. After comprehensive treatment of antiviral by acyclovir, mannitol dehydration to reduce intracranial pressure, human immunoglobulin to regulateimmunity, minocycline hydrochloride capsule, levofloxacin mesylate and sodium chloride against Rickettsia felis infection, control of seizure and pulmonary infection, the patient's condition was improved and then discharged. By summarizing the experience and lessons in the treatment of this patient, we hope to remind everyone to strengthen the understanding of Rickettsia felis infection.

Granulomatous mastitis caused by Rickettsia species.

Granulomatous mastitis is a rare inflammatory disease of varying etiology. Tuberculosis and cystic neutrophilic granulomatous mastitis caused by Corynebacterium are the best-established infectious examples. Despite the increasing incidence of Rickettsia-related diseases worldwide, granulomatous inflammation of breast parenchyma caused by Rickettsia has not yet been reported. We present a unique case of bilateral granulomatous mastitis documented with mammography, magnetic resonance imaging and core-needle biopsy. The rickettsial etiology of the disease was proved with specific immunohistochemistry and confirmed with DNA extraction, PCR and serology. The lesions completely resolved after a full-course tetracycline treatment. This case report widens the knowledge about the possible clinical manifestations of Rickettsia infection and adds a new bacterium to the list of etiological factors causing granulomatous mastitis.

Scalp eschar and neck lymphadenopathy by Rickettsia slovaca after Dermacentor marginatus tick bite case report: multidisciplinary approach to a tick-borne disease.

BACKGROUND: Scalp Eschar and Neck LymphAdenopathy after Tick bite is a zoonotic non-pathogen-specific disease most commonly due to Rickettsia slovaca and Rickettsia raoultii. Diagnosis is mostly based only on epidemiological and clinical findings, without serological or molecular corroboration. We presented a clinical case in which diagnosis was supported by entomological identification and by R. slovaca DNA amplifications from the tick vector. CASE PRESENTATION: A 6-year-old child presented with asthenia, scalp eschar and supraclavicular and lateral-cervical lymphadenopathy. Scalp Eschar and Neck LymphAdenopathy After Tick bite syndrome following a Dermacentor marginatus bite was diagnosed. Serological test on serum revealed an IgG titer of 1:1024 against spotted fever group rickettsiae, polymerase chain reaction assays on tick identified Rickettsia slovaca. Patient was successfully treated with doxycycline for 10 days. CONCLUSIONS: A multidisciplinary approach including epidemiological information, clinical evaluations, entomological identification and molecular investigations on tick, enabled proper diagnosis and therapy.