Intraocular inflammation as the main manifestation of Rickettsia conorii infection

Boutonneuse Fever in Southeastern Romania

Boutonneuse fever (BF) is an eruptive disease and is classified as a spotted fever, which is endemic in the Mediterranean basin (i.e., Marseille fever or Mediterranean spotted fever) and the Black Sea, caused by Rickettsia conorii, with dog ticks being a vector (i.e., Rhipicephalus sanguineus). In Romania, although the first reported outbreak of BF occurred during the summer of 1931 in Constanta, the disease was discovered in 1910. Although the disease has occurred most frequently in the two counties of the Dobruja region (Constanta and Tulcea), a region of the Balkan Peninsula, during the last few years, other counties in southeastern Romania have started to report BF cases. In a period of 9 years, 533 cases were registered in Constanta county, while in a period of 11 years, 339 cases were registered in Bucharest county. In this review, we describe the bacterial tick-borne disease caused by R. conorii in southeastern Romania, focusing on its history and epidemiology, pathophysiology, clinical aspects, diagnosis, treatment and preventive measures in the context of climate changes. Although R. conorii is the principal etiologic agent of BF in southeastern Romania, we should take into consideration that other Rickettsia spp. could be present and involved in disease transmission.

Epidemic Retinitis with Positive or Negative Weil Felix Test - a Comparative Study and Outcome with Doxycycline

PURPOSE

To compare clinical manifestations and disease outcomes in Epidemic Retinitis (ER) with positive or negative Weil Felix Test (WFT).

METHODS

Retrospective, observational, comparative study. WFT positive or negative patients formed Group 1 and 2, respectively. Patients receiving oral doxycycline monotherapy formed subgroup A and B. Duration of resolution of macular edema and retinitis was compared.

RESULTS

Novel finding of "ring retinitis" was observed equally in group 1 and 2. Complete resolution of macular edema took 41.3 days (range: 30-60 days) and 43.68 days (range: 20-105 days) (p = .668) and retinitis lesions resolved in 34.3 days (range: 14-65 days) and 34 days (range: 12-60 days) (p = .875) in group A and B, respectively. All (n = 14) eyes with retinitis within 1 disc diameter of fovea improved better than 20/80 except 1.

CONCLUSION

No significant difference with respect to clinical, imaging findings and the treatment outcome was observed in WFT positive or negative cases.

Rickettsia rickettsii infection as an unusual cause of pediatric retinitis: A case report

Purpose

To report a case of infectious pediatric retinitis attributed to Rocky Mountain spotted fever which is rarely reported in the United States.

Observations

A previously healthy 14-year-old male return traveler from Mexico was admitted to the pediatric ICU with septic shock and a diffuse rash. He subsequently complained of blurry vision and was found to have evidence of retinitis on exam. Infectious workup revealed high titers of rickettsial IgM and IgG antibodies. He was treated successfully with 14 days doxycycline and followed up in clinic with improvement in his visual complaints and retinitis.

Conclusions and importance

Rickettsioses are worldwide endemic zoonotic infections caused by Gram negative obligate intracellular bacteria and spread to humans by infected ticks. Rickettsial infections, including Rocky Mountain spotted fever caused by Rickettsia rickettsii, are a cause of infectious retinitis, and atypical and zoonotic infections should remain on the differential diagnosis for patients presenting with rash, systemic illness, and visual complaints, even if the patient's travel or exposure history do not immediately suggest a likely rickettsial infection. In general, the ocular manifestations of rickettsial infection improve with systemic doxycycline treatment of the underlying infection.

Ocular Manifestations of Emerging Arthropod-Borne Infectious Diseases

Purpose

To review the clinical features, diagnosis, treatment modalities, and prognosis of arthropod-borne infectious diseases.

Methods

This is a narrative review on arthropod-borne infectious diseases including general and ophthalmological aspects of these infectious diseases. A comprehensive literature review between January 1983 and September 2020 was conducted in PubMed database. Epidemiology, clinical features, diagnosis, treatment, and prognosis of arthropod-borne infectious diseases were reviewed.

Results

Emergent and resurgent arthropod-borne infectious diseases are major causes of systemic morbidity and death that are expanding worldwide. Among them, bacterial and viral agents including rickettsial disease, West Nile virus, Dengue fever, Chikungunya, Rift valley fever, and Zika virus have been associated with an array of ocular manifestations. These include anterior uveitis, retinitis, chorioretinitis, retinal vasculitis, and optic nerve involvement. Proper clinical diagnosis of any of these infectious diseases is primarily based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. The diagnosis is confirmed by laboratory tests. Ocular involvement usually has a self-limited course, but it can result in persistent visual impairment. Doxycycline is the treatment of choice for rickettsial disease. There is currently no proven specific treatment for arboviral diseases. Prevention remains the mainstay for arthropod vector and zoonotic disease control.

Conclusions

Emerging arthropod vector-borne diseases should be considered in the differential diagnosis of uveitis, especially in patient living or with recent travel to endemic countries. Early clinical diagnosis, while laboratory testing is pending, is essential for proper management to prevent systemic and ocular morbidity.

Mediterranean Spotted Fever: Current Knowledge and Recent Advances

Mediterranean spotted fever (MSF) is an emerging tick-borne rickettsiosis of the spotted fever group (SFG), endemic in the Mediterranean basin. By virtue of technological innovations in molecular genetics, it has been determined that the causative agent of MSF is Rickettsia conorii subspecies conorii. The arthropod vector of this bacterium is the brown dog tick Rhipicephalus sanguineus. The true nature of the reservoir of R. conorii conorii has not been completely deciphered yet, although many authors theorize that the canine population, other mammals, and the ticks themselves could potentially contribute as reservoirs. Typical symptoms of MSF include fever, maculopapular rash, and a characteristic eschar (“tache noire”). Atypical clinical features and severe multi-organ complications may also be present. All of these manifestations arise from the disseminated infection of the endothelium by R. conorii conorii. Several methods exist for the diagnosis of MSF. Serological tests are widely used and molecular techniques have become increasingly available. Doxycycline remains the treatment of choice, while preventive measures are focused on modification of human behavior and vector control strategies. The purpose of this review is to summarize the current knowledge on the epidemiology, pathogenesis, clinical features, diagnosis, and treatment of MSF.

Clinical profile and response to steroids in post-fever retinitis: a nine-year experience from a referral institute in the rural hinterland of Central India

PURPOSE

To describe the demographics, clinical features, and treatment outcomes with systemic steroids in eyes presenting with post-fever retinitis (PFR) from Central India.

METHODS

Single-center, retrospective analysis of 147 eyes of 98 PFR cases between 2011 and 2019.

RESULTS

Mean age of the study cohort was 33.46 ± 12.76 years, with 72 males and 26 females. The mean interval between the onset of fever and the diminution of vision was 21.10 ± 13.54 days (range 0-60 days). The number of PFR cases increased over the nine years with 89 cases (90.1%) presenting during winters. Unilateral involvement was seen in 49 cases, while 49 had bilateral involvement. Clinical characteristics included: multifocal retinitis (n = 122; 61.2%), hemorrhages (n = 132; 89.8%), disc edema (n = 57; 38.8%), anterior chamber reaction (n = 28; 19%), and vitritis (n = 103; 70.1%). Treatment included intravenous followed by oral steroids in 70 patients and oral steroids exclusively in 23; five patients denied treatment. The visual acuity improved from 1.09 ± 0.52 LogMAR to 0.29 ± 0.42 LogMAR (p < 0.05).

CONCLUSION

There has been an increase in the prevalence of PFR cases over the last decade with clustering during the winters. Multifocal retinitis, retinal hemorrhages, and vitritis were the most common clinical findings in our series. The retinitis resolved with improvement in vision following steroid therapy in all eyes.

Epidemic retinitis and community outbreaks

Purpose:

The objective of this study was to correlate seasonal variation of epidemic retinitis (ER) with concurrent community outbreaks.

Methods:

This is a retrospective, observational, comparative study conducted in a tertiary care eye hospital in south India. Monthly variation in number of ER cases in comparison with reported community outbreaks by Integrated Disease Surveillance Program (IDSP) from 2009 to 2020 in the same region were studied. Month-wise graphs against number of patients were plotted for ER and for each community outbreak.

Results:

ER was diagnosed in 163 patients. Diagnosis of presumed rickettsial ER was made in 48 cases (29.44%), chikungunya in 5, dengue in 3 and typhoid in 6 cases, while in other cases the etiological diagnosis remained uncertain (n = 101). Multiple positive serological tests were seen in 6 patients (Weil Felix Test (WFT) with WIDAL in 4 and chikungunya IgM with WFT in 2 patients). Relevant reported outbreaks by IDSP were: Pyrexia of unknown origin (PUO) (n = 5148), Chikungunya (n = 6577), Dengue (n = 7350), Measles (n = 1422), Mumps (n = 881), Rubella (n = 288), Malaria (n = 2262), Chicken Pox (n = 2385), Typhoid (n = 597), Kyasanur Forest Disease (n = 381), Scrub Typhus (n = 13), Typhus fever (n = 4), Japanese Encephalitis (n = 15). None of the outbreak graphs pattern was identical or similar to the graph of ER. Inverse relation of the graph of dengue outbreak with ER was observed.

Conclusion:

Inverse correlation between dengue and ER should be further studied for causation, which we believe may prove dengue as least common cause. Reporting of rickettsial outbreaks should be enhanced by undertaking statewide awareness and procurement of gold standard tests.

Expansion of Tick-Borne Rickettsioses in the World

Tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus Rickettsia. These infections are among the oldest known diseases transmitted by vectors. In the last three decades there has been a rapid increase in the recognition of this disease complex. This unusual expansion of information was mainly caused by the development of molecular diagnostic techniques that have facilitated the identification of new and previously recognized rickettsiae. A lot of currently known bacteria of the genus Rickettsia have been considered nonpathogenic for years, and moreover, many new species have been identified with unknown pathogenicity. The genus Rickettsia is distributed all over the world. Many Rickettsia species are present on several continents. The geographical distribution of rickettsiae is related to their vectors. New cases of rickettsioses and new locations, where the presence of these bacteria is recognized, are still being identified. The variety and rapid evolution of the distribution and density of ticks and diseases which they transmit shows us the scale of the problem. This review article presents a comparison of the current understanding of the geographic distribution of pathogenic Rickettsia species to that of the beginning of the century.

Rickettsia conorii retinitis: an emerging infection in the southeast of the Iberian Peninsula

CASE REPORT

A case is presented of a 60-year-old patient with loss of visual acuity in both eyes after fever and skin rash with palmoplantar involvement. After a complete examination and relevant complementary tests, the diagnosis of retinitis was made in the context of Rickettsia conorii infection. The evolution after treatment with doxycycline and prednisone at six weeks with significant anatomical and functional improvement is presented. Rickettsiosis is an emerging zoonosis that can present with ocular involvement. This is usually a multifocal retinitis affecting posterior pole with macular serous detachment and vitritis. Clinical suspicion will require serological confirmation for a definitive diagnosis. Treatment with antibiotics and corticosteroids has been shown to be effective. It should be taken into account in Mediterranean endemic areas, and in in the summer period, where the risk is much higher.

Spotted fever rickettsiosis presenting with bilateral anterior uveitis and retinitis: A case report

Spotted fever is a common rickettsial disease in India. It is caused by Rickettsia conorii, which demonstrates vascular tropism and causes endothelial injury. Ocular manifestations include multifocal retinitis and disc edema. Anterior uveitis as a presenting feature of spotted fever is uncommon. We present a 32-year-old man with spotted fever and bilateral anterior uveitis.

Tick- and flea-borne rickettsioses in Tizi-Ouzou, Algeria: Implications for travel medicine

BACKGROUND

In Algeria, Mediterranean spotted fever (MSF), caused by Rickettsia conorii conorii and transmitted by Rhipicephalus sanguineus, is endemic. However, the documentation of cases is rare due to a lack of laboratory facilities. Our aim was to screen for rickettsioses in patients with fever, rash and a possible inoculation eschar.

MATERIALS AND METHODS

Between 2013 and 2015, patients with a fever and a rash presenting at hospitals in the Tizi-Ouzou region were prospectively included in our study. Sera were screened using Indirect Immunofluorescence Assay (IFA) and qPCR was performed on swab samples from eschars.

RESULTS

One hundred and sixty-six patients were included. For 57 patients, MSF due to R. conorii conorii was diagnosed by serology and qPCR on a swab eschar sample. Three patients were diagnosed with murine typhus, a flea borne rickettsiosis. In addition, two patients had a positive serology in IgM for R. felis. For nine patients, serology for rickettsiosis was positive, but the specific rickettsia involved could not be determined. Nine patients had a severe disease with neurological involvement or multi-organ failure.

CONCLUSION

Clinicians should routinely screen for rickettsioses in patients and travellers presenting with a rash upon return from Algeria. Doxycycline treatment must be given promptly because the prognosis can be severe.

Ocular manifestations of rickettsia in children: common but frequently overlooked

We review two cases of ocular manifestations of Rickettsia conorii infection in children. A girl who presented unilateral visual loss with focal retinitis and macular oedema and a boy with unilateral central scotoma and bilateral anterior uveitis. Progressive functional and anatomic recovery was observed after oral antibiotics and steroids were initiated.

Epidemic Retinitis

Purpose: To study demography, seasonal variation, clinical presentation, and treatment outcome of "retinitis post febrile illness." (RpFI) Method: Case records of patients diagnosed as RpFI, from July 2009 to May 2017 were studied retrospectively. Patients with complete follow up were evaluated for treatment and visual outcomes. Results: Two hundred and five eyes of 119 patients were studied. The peak incidence of RpFI was from November to March each year. Diagnosis of fever largely remained unknown. Chikungunya IgM, Dengue IgM, and Weil-Felix test was positive in 22.22%, 15.38%, and 39.75%, respectively, in investigated cases. The mean visual acuity at presentation and at resolution was 20/63 and 20/32, respectively, in 122 eyes with complete follow up. Conclusion: We suggest a term "Epidemic Retinitis" for RpFI due to its seasonal variation and to differentiate it from other sporadic forms of retinitis. Although RpFI has aggressive presentation, it resolves over 3-4 months and the overall visual outcome is satisfactory.

Seroprevalence against Rickettsia and Borrelia Species in Patients with Uveitis: A Prospective Survey

Vector-borne diseases such as Lyme borreliosis and rickettsioses have been associated with ocular inflammation. Our aim was to study patients with diagnosed uveitis to evaluate serological signs of infection or exposure to these tick-borne agents. Forty-eight patients were prospectively examined with serology together with medical records and a questionnaire concerning previous exposure, diseases, and treatments. Seven patients (14.6%) showed seroconversion to Rickettsia spp. between acute and convalescent phase sera, which provides support for a positive Rickettsia diagnosis according to guidelines. The specificity was confirmed by Western blot. Additional 28 patients had stationary titres of which eight (16.6%) had 1 : 256 or higher titre in the first serum, and another 13 patients were seronegative. No epidemiological risk factor or marker could be identified. For Borrelia, only three patients showed moderate IgG titres. A control group of 100 blood donors, 60 patients with rheumatic disease, and 56 patients seeking medical care were tested of which 2.0–7.1% showed low anti-Rickettsia titres and 3.0–8.3% anti-Borrelia titres. The findings are indicative for an association between infection or exposure to Rickettsia spp. and uveitis with a seropositivity among patients with recurrent uveitis in concordance with the spread of rickettsial exposure in a tick-exposed population.

[Tropical ophthalmology : Intraocular inflammation caused by "new" infectious pathogens and travel-related infections]

A number of "new" (emerging) infections that can also cause inflammatory eye changes are appearing and becoming increasingly important. In the past, diseases such as chikungunya, dengue fever or West Nile virus infections were endemic in tropical regions, but are now expanding worldwide and causing significant morbidity and even mortality. "Globalization" and human migration are important factors leading to the import of these infections. Climate changes are probably even more important. Increasing temperatures provide suitable conditions for new vectors, and may lead to autochthonous transmission of infectious pathogens. Diagnosis of these diseases requires not only careful assessment of medical and travel history, but also the application of specific laboratory diagnostic tests. A broad spectrum of ocular involvement has been reported, with frequent posterior segment involvement. Emerging infections should therefore be considered in the differential diagnosis of retinitis, chorioretinitis, retinal vasculitis and optic neuropathy in a patient living in or traveling back from an endemic area. Since these infections are often vector (insect) borne and effective treatments are almost uniformly lacking, prevention is at least as important as prompt diagnosis and initiation of supportive care. Here, we focus on Chikungunya, Dengue fever, Ebola fever, the West Nile virus and Rickettsioses, which frequently demonstrate ocular involvement.

A case of uveitis due to Rickettsia conorii infection in Southeastern France

We describe a case of skin rash and bilateral uveitis secondary to Rickettsia conorii infection. A 60-year-old female patient, living in the rural hinterland of Cannes, was referred to our hospital in mid-August 2012 for skin rash, fever, and arthromyalgia. Blood tests showed increased inflammatory markers, hepatic cytolysis and anicteric cholestasis. Ophthalmic examination revealed bilateral papillitis and focal chorio-retinitis. Fluoroscopic angiography demonstrated early hypofluorescence, with a few arteriolar occlusions, and subsequent hyperfluorescence and focal vasculitis. R. conorii antibodies were identified by immunofluorescence antibody test. Investigation of other infective agents and the immunological panel were negative. A 2-week course of doxycycline 200 mg/day was prescribed, and fever rapidly subsided, the skin rash resolved and vision improved. Ophthalmic examination a month and a half later showed almost all retinal lesions had disappeared and inflammation markers had returned to normal.

Parinaud's oculoglandular syndrome revealing subclinical Rickettsia conorii infection

The purpose of this study was to report a case of Parinaud's oculoglandular syndrome associated with subclinical Rickettsia conorii infection. We report a case of a 66-year-old male patient presented with unilateral persistent granulomatous conjunctivitis in the left eye and an ipsilateral preauricular lymphadenopathy without associated systemic features. Laboratory evaluation showed a positive indirect immunofluorescence antibody test for R. conorii. The patient received a 2-week course of oral doxycycline, with subsequent complete resolution of all his symptoms. Rickettsial disease should be considered in the differential diagnosis of oculoglandular syndrome with or without associated systemic symptoms in any patient living in or returning from a specific endemic area.

Rickettsial infection caused by accidental conjunctival inoculation

The most common transmission route of tick-borne Rickettsia is through tick bite; nevertheless, other transmission routes should also be considered. We report a case of rickettsial infection in a 15-year-old boy caused by accidental contamination of the conjunctiva through the infected fluid of a crushed engorged tick removed from a dog. Right eye pain, conjunctival hyperaemia with mucopurulent exudate, chemosis and eyelid oedema were the first signs and symptoms. Two days later, the boy developed fever, myalgia, headache, abdominal pain and was vomiting; physical examination showed multiple cervical adenopathies but no rash. He was treated with doxycycline (200 mg/day) for 7 days with progressive resolution of clinical signs. Rickettsial infection was confirmed by immunofluorescence assay with serological seroconversion in two consecutive samples. Rickettsia conorii or Rickettsia massiliae were the possible causal agents since they are the Rickettsia spp found in the Rhipicephalus sanguineus dog tick in Portugal.

A rare case of retinal artery occlusion in the context of mediterranean spotted Fever

BACKGROUND

Mediterranean spotted fever is a zoonosis endemic in the Mediterranean region. The microorganism Rickettsia conorii is responsible for the disease due to its angiotropism for endothelial cells. It produces host cell necrosis, thrombosis, and organ dysfunction. Ophthalmologic manifestations are rare.

FINDINGS

The authors describe the case of a 55-year-old female with Mediterranean spotted fever who developed localized retinal vasculitis with associated macular edema. Treatment with intravitreal triamcinolone allowed a significant recovery of visual acuity.

CONCLUSION

Ophthalmological symptoms in these patients should be emphasized because there can be severe ocular complications with a potentially irreversible loss of visual acuity.

Ocular manifestations of emerging infectious diseases

PURPOSE OF REVIEW

Emergent and resurgent infectious diseases are major causes of systemic morbidity and death that are expanding worldwide mainly because of climate changes and globalization. Among them, specific diseases have been recently associated with ocular involvement. This review presents the ocular manifestations of selected emerging infectious diseases relevant to the ophthalmologist.

RECENT FINDINGS

An array of ocular manifestations, involving mainly the posterior segment, have been recently described in association with specific arthropod vector-borne diseases including rickettsioses, West Nile virus, Rift Valley fever, Dengue fever, and Chikungunya. Influenza A (H1N1) virus has also been recently associated with ocular involvement. On the contrary, with advances in laboratory testing applied to ocular fluids, new infectious agents, mainly viruses, are increasingly being found to be associated with uveitis.

SUMMARY

Emerging infectious diseases should be considered in the differential diagnosis of retinitis, chorioretinitis, retinal vasculitis, optic neuropathy, or any other ocular inflammatory condition in a patient living in or traveling back from a specific endemic area. On the contrary, ocular fluid sampling and analysis for specific new pathogens can be recommended in selected patients with uveitis of unexplained cause.

Update on tick-borne rickettsioses around the world: a geographic approach

Tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus Rickettsia. These zoonoses are among the oldest known vector-borne diseases. However, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. Several species of tick-borne rickettsiae that were considered nonpathogenic for decades are now associated with human infections, and novel Rickettsia species of undetermined pathogenicity continue to be detected in or isolated from ticks around the world. This remarkable expansion of information has been driven largely by the use of molecular techniques that have facilitated the identification of novel and previously recognized rickettsiae in ticks. New approaches, such as swabbing of eschars to obtain material to be tested by PCR, have emerged in recent years and have played a role in describing emerging tick-borne rickettsioses. Here, we present the current knowledge on tick-borne rickettsiae and rickettsioses using a geographic approach toward the epidemiology of these diseases.

New infectious etiologies for posterior uveitis

Emergent and resurgent arthropod vector-borne diseases are major causes of systemic morbidity and death and expanding worldwide. Among them, viral and bacterial agents including West Nile virus, Dengue fever, Chikungunya, Rift Valley fever, and rickettsioses have been recently associated with an array of ocular manifestations. These include anterior uveitis, retinitis, chorioretinitis, retinal vasculitis and optic nerve involvement. Proper clinical diagnosis of any of these infectious diseases is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. The diagnosis is usually confirmed by the detection of a specific antibody in serum. Ocular involvement associated with emergent infections usually has a self-limited course, but it can result in persistent visual impairment. There is currently no proven specific treatment for arboviral diseases, and therapy is mostly supportive. Vaccination for humans against these viruses is still in the research phase. Doxycycline is the treatment of choice for rickettsial diseases. Prevention, including public measures to reduce the number of mosquitoes and personal protection, remains the mainstay for arthropod vector disease control. Influenza A (H1N1) virus was responsible for a pandemic human influenza in 2009, and was recently associated with various posterior segment changes.