Mediterranean spotted fever-like illness in Sardinia, Italy: a clinical and microbiological study

A case report of fatal Rickettsia japonica bloodstream infection in Zhejiang, China

Japanese spotted fever (JSF) is an emerging acute febrile natural infectious disease caused by the neglected zoonotic pathogen Rickettsia japonica. Here we reported a 64-year-old female patient who initially presented to the local hospital with an intermittent fever of unknown origin (FUO). A systemic, evident edema and eschar on the skin of the patient's upper limb was observed. The patient was diagnosed with critical Rickettsia japonica bloodstream infection by Q-mNGS and treated with doxycycline, as well as symptomatic treatments. Unfortunately, the patient passed away as a result of complications of septic shock and multiple organ and acute respiratory failure. Delayed treatment resulting from the nonspecific clinical symptoms in the early stages of infection can lead to fatal complications. Q-mNGS is an emerging pathogen detection method with the advantages of comprehensive detection, high accuracy and sensitivity and should be promoted and applied by clinicians.

A Case of Critical Japanese Spotted Fever in Zhejiang, China

Background

Japanese spotted fever (JSF) is a rare disease, caused by Rickettsia japonica; no case has been reported in Zhejiang Province, China.

Case Presentation

An elderly woman presented to the hospital with abdominal pain and fever. Her condition rapidly worsened with severe complications, such as multiple organ failure and central nervous system damage. The presence of R. japonica was quickly detected by metagenomic next-generation sequencing. On the basis of combined clinical manifestations and laboratory results, critical JSF was diagnosed and treated with doxycycline. The patient showed good prognosis. Typical symptoms (eschar and rash) were not observed in the early stage, consequently increasing the difficulty of clinical diagnosis.

Conclusion

The delay of treatment caused by non-specific symptoms is an important factor affecting the progression of JSF. As an emerging pathogen detection method, mNGS has been successfully applied for disease diagnosis and treatment, and can be an important complement for the diagnosis of this disease.

Differential detection of tick-borne pathogens in human platelets and whole blood using microfluidic PCR

The tick-borne pathogens (TBPs) with adhesive phenotype can use platelets for dissemination and colonization of distant tissues and organs, and it has been shown that they can be found concentrated in the platelet fraction of blood. This study shows the differential presence of TBPs in samples of human platelet fraction (n = 68), whole blood samples (n = 68) and ticks collected (n = 76) from the same individuals, using an unbiased high-throughput pathogen detection microfluidic system. The clinical symptoms were characterized in enrolled patients. In patients with suspected TBP infection, serological assays were conducted to test for the presence of antibodies against specific TBPs. Tick species infesting humans were identified as Ixodes ricinus, Dermacentor reticulatus, and Haemaphysalis punctata. Eight patients developed local skin lesions at the site of the tick bite including non-specific lesions, itching sensation at the lesion site, and eschar. Most common TBPs detected in platelet fraction were Borrelia spielmanii and Rickettsia sp., followed by Borrelia afzelii and Anaplasma phagocytophilum. Multiple infections with three TBPs were detected in platelet fraction. In whole blood, most common TBPs detected were Anaplasma spp. and A. phagocytophilum, followed by Rickettsia spp. and B. afzelii. In ticks, the most common TBP detected was Rickettsia spp., followed by Borrelia spp. and Anaplasma spp. Overall, nine different pathogens with variable prevalence were identified using species-specific primers, and the most common was Rickettsia helvetica. In three patients, there were no coincidences between the TBPs detected in whole blood and tick samples. Only in one patient was detected A. phagocytophilum in both, whole blood and tick samples. These results suggest the unequal detection of TBPs in whole blood, platelet fraction and ticks collected, from the same individual. The results justify the use of both whole blood and platelet fraction for molecular diagnosis of TBPs in patients.

Emerging tick-borne spotted fever group rickettsioses in the Balkans

The impact of tick-borne pathogens (TBPs) on human health has increased in the last decades, since the incidence of emerging and re-emerging infectious and zoonotic tick-borne diseases has increased worldwide. Tick-borne rickettsiae of the Spotted Fever group (SFGR) are considered as emerging pathogens that can infect humans and cause a variety of non-specific clinical symptoms. Here, we report nine cases of atypical tick-borne diseases (9/460; 1.95%) that occurred over a period of four months (from 15 April 2021 to 16 August 2021) in Serbia, from which five cases were classified as confirmed SFGR infection, two cases as probable SFGR infection and two cases as suspected SFGR infection. Within cases of confirmed SFGR infection, R. helvetica was detected as the causative agent in two cases. The most common clinical finding was non-expanding persistent circular redness, followed by eschar and enlargement of regional lymph nodes, and pain at lesion site. Rickettsia outer membrane protein B (ompB) and citrate synthase (gltA) gene fragments were amplified from clinical samples and ticks attached to patients and IgG reacting with Rickettsia conorii antigen were detected in sera samples of patients, which are highly suggestive of exposure to SFGR. Surveillance and monitoring of rickettsial diseases in Serbia should continue and extended to new areas due to the increasing trend of clinical infections caused by SFGR in the country.

Rickettsiosis with Pleural Effusion: A Systematic Review with a Focus on Rickettsiosis in Italy

BACKGROUND

Motivated by a case finding of Mediterranean spotted fever (MSF) associated with atypical pneumonia and pleural effusion in which Rickettsia conorii subsp. israelensis was identified by molecular methods in the pleural fluid, we wanted to summarize the clinical presentations of rickettsiosis in Italy by systematic research and to make a systematic review of all the global cases of rickettsiosis associated with pleural effusion.

METHODS

For the literature search, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was followed. We chose to select only the studies published in last 25 years and confirmed both with serological and molecular assays.

RESULTS

Human cases of rickettsiosis in Italy were reported in 48 papers describing 2831 patients with very different clinical presentations; the majority was MSF accounted to R. conorii and was reported in Sicily. Pleural effusion associated with infection with microorganisms belonging to Rickettsiales was described in 487 patients. It was rarely associated with microorganisms different from O. tsutsugamushi; also rarely, cases of scrub typhus were reported outside Southeast Asia and in the largest majority, the diagnosis was achieved with serology.

CONCLUSIONS

MSF, especially when caused by R. conorii subsp. israelensis, may be a severe disease. A high index of suspicion is required to promptly start life-saving therapy. Pleural effusion and interstitial pneumonia may be part of the clinical picture of severe rickettsial disease and should not lead the physician away from this diagnosis.

Current tools for the diagnosis and detection of spotted fever group Rickettsia

Spotted fever group (SFG) rickettsiae causes a number of diseases in humans worldwide, which can range from mild to highly lethal. Since the clinical presentations of rickettsioses caused by SFG rickettsiae are variable and may be similar to the diseases caused by other rickettsiae, such as Orientia tsutsugamushi (agent for scrub typhus), Coxiella burnetii (agent for Q fever) and the typhus group rickettsiae (agents for epidemic and murine typhus), the accurate diagnosis of infections caused by SFG Rickettsia remains challenging especially in resource-poor settings in developing countries. This review summarizes the various diagnostic and detection tools that are currently available for the confirmation of infections by SFG rickettsiae. The advantages and challenges pertaining to the different serological and molecular detections methods, as well as new assays in development, are discussed. The utility of the detection tools contributing to the surveillance of SFG rickettsiae in arthropods and animals are reviewed.

Rickettsiales in Italy

There is no updated information on the spread of Rickettsiales in Italy. The purpose of our study is to take stock of the situation on Rickettsiales in Italy by focusing attention on the species identified by molecular methods in humans, in bloodsucking arthropods that could potentially attack humans, and in animals, possible hosts of these Rickettsiales. A computerized search without language restriction was conducted using PubMed updated as of December 31, 2020. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was followed. Overall, 36 species of microorganisms belonging to Rickettsiales were found. The only species identified in human tissues were Anaplasma phagocytophilum,Rickettsia conorii, R. conorii subsp. israelensis, R. monacensis, R. massiliae, and R. slovaca. Microorganisms transmissible by bloodsucking arthropods could cause humans pathologies not yet well characterized. It should become routine to study the pathogens present in ticks that have bitten a man and at the same time that molecular studies for the search for Rickettsiales can be performed routinely in people who have suffered bites from bloodsucking arthropods.

Spotted fever group rickettsiae (SFGR) detection in ticks following reported human case of Japanese spotted fever in Niigata Prefecture, Japan

Japanese spotted fever, a tick-borne disease caused by Rickettsia japonica, was firstly described in southwestern Japan. There was a suspicion of Rickettsia japonica infected ticks reaching the non-endemic Niigata Prefecture after a confirmed case of Japanese spotted fever in July 2014. Therefore, from 2015 to 2017, 38 sites were surveyed and rickettsial pathogens were investigated in ticks from north to south of Niigata Prefecture including Sado island. A total of 3336 ticks were collected and identified revealing ticks of three genera and ten species: Dermacentor taiwanensis, Haemaphysalis flava, Haemaphysalis hystricis, Haemaphysalis longicornis, Haemaphysalis megaspinosa, Ixodes columnae, Ixodes monospinosus, Ixodes nipponensis, Ixodes ovatus, and Ixodes persulcatus. Investigation of rickettsial DNA showed no ticks infected by R. japonica. However, three species of spotted fever group rickettsiae (SFGR) were found in ticks, R. asiatica, R. helvetica, and R. monacensis, confirming Niigata Prefecture as a new endemic area to SFGR. These results highlight the need for public awareness of the occurrence of this tick-borne disease, which necessitates the establishment of public health initiatives to mitigate its spread.

Epidemiology, Clinical Aspects, Laboratory Diagnosis and Treatment of Rickettsial Diseases in the Mediterranean Area During COVID-19 Pandemic: A Review of the Literature

The purpose of the present review is to give an update regarding the classification, epidemiology, clinical manifestation, diagnoses, and treatment of the Rickettsial diseases present in the Mediterranean area.

We performed a comprehensive search, through electronic databases (Pubmed – MEDLINE) and search engines (Google Scholar), of peer-reviewed publications (articles, reviews, and books).

The availability of new diagnostic tools, including Polymerase Chain Reaction and nucleotide sequencing has significantly modified the classification of intracellular bacteria, including the order Rickettsiales with more and more new Rickettsia species recognized as human pathogens. Furthermore, emerging Rickettsia species have been found in several countries and are often associated with unique clinical pictures that may challenge the physician in the early detection of the diseases.

Rickettsial infections include a wide spectrum of clinical presentations ranging from a benign to a potentially life treating disease that requires prompt recognition and proper management. Recently, due to the spread of SARS-CoV-2 infection, the differential diagnosis with COVID-19 is of crucial importance. The correct understanding of the clinical features, diagnostic tools, and proper treatment can assist clinicians in the management of Rickettsioses in the Mediterranean area.

Epidemiology and Diversity of Rickettsiales Bacteria in Humans and Animals in Jiangsu and Jiangxi provinces, China

Diseases caused by Rickettsiales bacteria are a global public health problem. To better understand the diversity and origins of Rickettsiales infection in humans and animals, we sampled 134 febrile patients, 173 rodents and 43 shrews, as well as 358 ticks, from two cities in Jiangsu and Jiangxi provinces, China. Our data revealed a relatively high prevalence of scrub typhus cases in both localities. In addition, both serological tests and genetic analysis identified three patients infected with Anaplasma bovis, Rickettsia monacensis, and Orientia tsutsugamushi bacteria. Molecular epidemiological investigation revealed the co-circulation of multiple species of Rickettsiales bacteria in small mammals and ticks in both provinces, potentially including novel bacterial species. In sum, these data demonstrate the ongoing importance of Rickettsiales infection in China and highlight the need for the regular surveillance of local arthropods, mammals and humans.

Mediterranean spotted fever rickettsiosis in Italy, 2001-2015: Spatio-temporal distribution based on hospitalization records

The Mediterranean spotted fever (MSF) rickettsiosis is the predominant rickettsial disease among the spotted fever group (SFG) rickettsiae in the Mediterranean countries and North Africa. Its causative agent is Rickettsia conorii, although, SFG rickettsiosis - cases due to Rickettsia monacensis, Rickettsia massiliae and Rickettsia aeschlimannii were also described. A retrospective study based on hospital discharge records with a diagnosis of SFG rickettsiosis was carried out to describe the spatial pattern, the trend of the disease, and the epidemiological characteristics of persons hospitalized in the period 2001-2015. Standardized hospitalization ratios were calculated at municipal level using the European population. Smoothed maps were produced using a localised smoothing Poisson model. The mean annual standardized hospitalization rate was 1.36/100,000 person years (95%CI: 1.34; 1.39). Rates showed strong summer seasonality and tended to decrease over time. During the study period, 28.89% of municipalities had smoothed standardized hospitalization ratios greater than 1 and 14.01% above 20. Higher standardized hospitalization ratios were found in areas along the Tyrrhenian coast, especially in the south of Calabria and in the islands of Sardinia and Sicily, where the disease is of public health relevance.

First molecular detection of the human pathogen Rickettsia raoultii and other spotted fever group rickettsiae in Ixodid ticks from wild and domestic mammals

Tick-borne rickettsioses are recognized as emerging vector-borne infections capable of infecting both human and animal hosts worldwide. This study focuses on the detection and molecular identification of species belonging to the genus Rickettsia in ticks sampled from human, vegetation, and domestic and wild vertebrates in Sardinia. Ticks were tested by PCR targeting gltA, ompA, and ompB genes, followed by sequencing analysis. The results provide evidences of a great variety of Rickettsia species of the Spotted fever group in Ixodid ticks and allow establishing for the first time the presence of R. raoultii in Rhipicephalus sanguineus s.l. and Dermacentor marginatus ticks in Sardinia island. Rickettsia massiliae was detected on R. sanguineus s.l. and R. aeschlimannii in Hyalomma marginatum and Hy. lusitanicum ticks. In addition, eight D. marginatus ticks were positive for R. slovaca. This study provides further evidence that different Rickettsia species are widespread in Sardinian ticks and that detailed investigations are required to understand the role these tick species play on spotted fever group rickettsiae circulation. More studies will provide new background on molecular epidemiology of zoonotic rickettsiae, the geographical distribution of tick-transmitted rickettsial pathogens, and the involvement of vertebrate hosts in propagation and maintenance of these bacteria in nature.

Clinically-diagnosed Mediterranean Spotted Fever in Malta

BACKGROUND

Mediterranean Spotted Fever (MSF) is a tick-borne zoonosis caused by Rickettsia conorii which is endemic in Malta, an island in the South Mediterranean that is a popular tourist destination. Diagnosis is frequently based on clinical manifestations as laboratory results are often limited to a retrospective diagnosis. We describe the clinical presentation, diagnosis and treatment of children <16 years who presented with MSF from 2011 to 2016.

METHOD

The demographics, clinical findings, laboratory results, management and outcome of all children hospitalised with suspected MSF based on the presence of fever and an eschar, were retrieved from their case notes.

RESULTS

Over the five-year study period six children, aged between 17 months and 15 years, were diagnosed with MSF. All children had contact with ticks and the majority presented in summer. Laboratory results were non-specific and included elevated inflammatory markers, lymphocytosis/lymphopenia and hyponatraemia. Serological and molecular techniques were used for diagnosis. Response to clarithromycin or doxycycline was immediate.

CONCLUSION

MSF should be included in the differential diagnosis of fever, rash and an eschar in children who travel to Malta. Despite advances in molecular diagnostics, clinical diagnosis remains important in the management of children with suspected MSF.

A five-year survey of tick species and identification of tick-borne bacteria in Sardinia, Italy

Sardinia is a hotspot for studying tick-borne diseases in the Mediterranean region, where cases of notifiable tick-borne diseases are increasing. The aim of this study was to determine the presence of tick-borne bacteria of medical and veterinary importance in ixodid ticks collected from domestic and wild animals, humans, and vegetation from different collection sites in Sardinia. Using standard PCR and sequencing techniques, the presence of Rickettsia, Anaplasma, Ehrlichia, and Bartonella species, as well as Coxiella burnetii was evaluated. A total of 1619 ticks were morphologically identified as Rhipicephalus sanguineus sensu lato, R. bursa, R. annulatus, Dermacentor marginatus, Haemaphysalis punctata, Ha. sulcata, Hyalomma lusitanicum, H. marginatum, Ixodes festai (sometimes referred to erroneously as I. ventalloi), and Argas reflexus. Results indicated the presence of several circulating pathogens in Sardinian ticks. DNA of Rickettsia species was detected in 58 out of 1619 (4%) belonging to R. sanguineus s.l., D. marginatus, Ha. punctata, H. marginatum, and I. festai species. Ehrlichia canis DNA was detected in 33 out of 1619 ticks (2%) belonging to R. sanguineus s.l., R. bursa, and Ha. punctata species. A total of 61 out of 1619 (4%) ticks (R. sanguineus s. l., R. bursa, Ha. punctata, and I. festai) tested positive for Anaplasma spp. Coxiella burnetii was detected in 21 out of 1619 (1%) ticks belonging to R. sanguineus s.l., R. bursa, R. annulatus, and H. marginatum species. Five R. sanguineus s.l. and one R. bursa ticks were positive for the presence of Bartonella sp. 16S rRNA gene. Our findings expand the knowledge on tick-borne microorganism repertoires and tick distribution in Sardinia. Tick distribution should be monitored for effective control of these arthropods and the infections they transmit.

Spotted fever group rickettsiae associated with ixodid ticks in wild environment in Southern Italy

Ixodidae ticks are vectors and reservoirs of several species of rickettsiae, and tick-borne rickettsioses are reported worldwide. This study was aimed to verify the distribution of spotted fever group rickettsiae associated with ticks in a wild environment, the National Park of Gargano, where there is proximity between wild and domestic animals, and which is within an endemic area for rickettsiosis. Ticks were collected from animals or vegetation, morphologically identified and tested by a PCR targeting the 17kDa gene, and by a loop-mediated isothermal amplification (LAMP) targeting ompB gene. Out of 34 tested tick pools, 2 from Dermacentor marginatus, 1 from Ixodes ricinus, and 1 from Rhipicephalus turanicus resulted positive. Nucleotide sequences of amplicons showed high similarity with sequences from Rickettsia slovaca, Rickettsia raoultii, Rickettsia helvetica, and Rickettsia felis. The overall calculated infection rate was 26.19 per 1,000, while it rose up to 107.77 when only D. marginatus was considered. The results highlight the association among Ri. slovaca, Ri. raoultii, D. marginatus and wild boars from which infected ticks were collected. Finally, the study shows the low efficacy of the previously described LAMP method for the detection of Rickettsia spp., when compared to PCR, making urgent the development of most effective LAMP protocols.

Tache Noire in a Patient with Acute Q Fever

OBJECTIVE

To describe a rare case of acute Q fever with tache noire.

CLINICAL PRESENTATION AND INTERVENTION

A 51-year-old man experienced acute Q fever showing tache noire, generally considered a pathognomonic sign of Mediterranean spotted fever (MSF) and MSF-like illness, but not a clinical feature of Q fever. The patient was treated with doxycycline 100 mg every 12 h.

CONCLUSION

In the Mediterranean area, tache noire should be considered pathognomonic of MSF but it should not rule out Q fever. Clinical diagnosis should be supported by accurate laboratory diagnostic tests to guide proper management.

A case of Q fever with erythema nodosum

BACKGROUND

Acute Q fever is asymptomatic in 60% of the patients, while the reminder may present with fever, pneumoniae, and hepatitis. Skin manifestations are uncommon including transient punctiform rashes, purpuric, or maculopapular eruptions. Erythema nodosum have seldom been reported.

CASE PRESENTATION

A 37-year-old female presented with fever for 1 month and skin lesions consists of erythematous painful nodule of the legs. Serological testing for Coxiella burnetii was positive. Treatment consisted with doxycycline for 2 weeks. Evolution was favorable. The patient completely recovered and had no evidence of skin lesion 1 month later.

CONCLUSION

Because of its nonspecific clinical presentation, Q fever with erythema nodosum is probably underestimated. Q fever should be evocated when facing unexplained erythema nodosum even if there is not other typical clinical manifestation of Q fever.