Rickettsia Research Articles

Health facility-based prevalence of typhoid fever, typhus and malaria among individuals suspected of acute febrile illnesses in Southwest Region, Ethiopia.

Acute febrile illnesses such as typhoid fever, typhus, and malaria are still major causes of hospital admission in many parts of Ethiopia. However, there are substantial gaps in the monitoring systems, which result in a lack of knowledge about the geographic distribution and role of common pathogens, particularly in rural areas. Thus, this study was aimed at assessing the seroprevalence of typhoid fever, typhus, and malaria among suspected acute febrile patients at the MTU Teaching Hospital and Mizan-Aman Health Center, Southwest region of Ethiopia. A health facility-based cross-sectional study was carried out from July to October 2022. Blood samples were collected from a total of 384 individuals. Widal and Weilfelix direct card agglutination and tube agglutination test methods were used for the Salmonella enterica serotype Typhi (S. typhi) and Rickettsia infections. The diagnosis of malaria was made using thick and thin blood smears. Questionnaires given by interviewers were used to gather information on risk factors and other sociodemographic factors. The data was analyzed using STATA/SE 14.0. A total of 371 patients were tested for S. Typhi and Rickettsia infections using direct card agglutination and tube agglutination methods. Using the screening test, 20.5% (76/371) patients were reactive either for O or H antigens or both, of which 55.3% (42/76) were reactive by the titration test at the cutoff value ≥ 1:80. About 17.5% (65/371) were reactive to OX19 antigen by card agglutination test, and of which 58.5% (38/65) were reactive by the titration test at the cutoff value ≥ 1:80. The overall seroprevalence of S. Typhi and Rickettsia infections using combined direct card and tube agglutination techniques was 11.3% (42/371) and 10.2% (38/371), respectively. Out of 384 suspected malaria patients, 43 (11.2%) were found positive either for P. falciparum, 27 (7.03%), or P. vivax, 16 (4.2%). In this study, typhoid fever, typhus, and malaria were found among symptomatic acute febrile patients. To increase disease awareness, it is necessary to provide sustainable health education about risk factor behaviors, disease transmission, and prevention strategies. In addition, improving laboratory diagnosis services and early treatment may also lower the likelihood of potentially fatal consequences.

Epidemiological and Clinical Features of Rickettsial Infection Among Australian Individuals from 2015 to 2018

Objective: In this study, the clinical, laboratory and epidemiological features of rickettsial infection in Australian patients were examined. Methods: Patients with Rickettsia spp. seropositivity were selected from the database of the Australian Rickettsial Reference Laboratory. Questionnaires were sent to each referring physician with a request for information regarding the patient’s illness. Results: A retrospective analysis of 178 patients revealed the following common features in Australian rickettsial infection: fever, headache, myalgia, rash and a history of recent exposure to the Australian bush. The history included tick bites, eschar presence, respiratory abnormalities and acute fatigue, accompanied by abnormal haematology and liver function tests. Conclusions: A differential diagnosis including rickettsial infection should be confirmed (or refuted) by rickettsial serology.

Human rickettsial infections in India - A review.

Rickettsial infections are emerging and/or re-emerging disease that poses a serious global threat to humans and animals. Transmission to humans and animals is through the bite of the ectoparasites including ticks, fleas and chigger mites. Most of the rickettsial diseases are endemic in India, but underdiagnosed. This review is aimed at analyzing the prevalence of rickettsiosis in India and the advancement of rickettsial diagnosis. We have conducted a systematic review on the prevalence of rickettsial disease in India ranging from 1.3% to 46.6% for spotted fever, 2.4% to 77.8% for scrub typhus and 1% to 46.4% for Q fever, based on the literature published with the evidence of isolation, serological, and molecular diagnostics. Search engines Medline/PubMed, Science Direct, ProQuest, and EBSCO were used to retrieve the articles from electronic databases by using appropriate keywords to track the emergence of these rickettsial diseases in India for the period of 1865 to till date. We retrieved 153 published rickettsial articles on hospital-based studies from India that were purely made on the basis of prevalence and the laboratory parameters viz., Weil-Felix test (WF) and Rapid Immunochromatographic tests (RICT) with reference to the gold standard IFA and ELISA. More epidemiological studies are required for epidemic typhus to know the exact prevalence status of this louse-borne rickettsiosis in India. Currently, there is no confirmed specific inflammatory marker for rickettsial diseases. Moreover, serological cross-reactivity is an important aspect, and it should be investigated in endemic areas, there is also a need to include molecular diagnostic techniques for further confirmation in healthcare settings.

To Study Clinical Profile and Significance of Rathi Goodman Aghai Score System in Rickettsial Infection in Central Maharashtra

Abstract Introduction: Rickettsial disease has nowadays emerging as one of the most common causes of exanthematous fever with rash with high mortality and morbidity. Rickettsial fever cases are being reported from all over India. Objectives: The study aims to evaluate prevalence, demographic and clinical details of the cases of rickettsial infection in central India and to assess the significance of Rathi Goodman Aghai (RGA) score and Weil Felix test in diagnosis of rickettsial infection. Materials and Methods: It was a retrospective, analytical comparative study. Patients between age group of 2 months to 18 years from endemic area presenting with fever of more than 4 days duration and/or typical rash (maculopapular/necrotic) with eschar and supporting laboratory test were included in the study. Patients’ demographic and clinical data were analyzed by the software STATA software. and Chi square test. Results: The most common age group affected was between 1 and 5 years (38.09%). 76.19% of patients were from rural area. All the patients 21 (100%) presented with fever. The most common complication was meningoencephalitis (42.85%). Rathi Aghai score was positive in 90.47% of the patients. Weil Felix test was positive in 85.71% cases, out of which 33.33% of patients had OXK strain. The sensitivity and specificity of RGA score was found to be 94.44% and 33.33%, respectively, with positive predictive value of 89.47%. Conclusion: RGA score is a good tool for diagnosis of rickettsial infection with sensitivity and specificity of 94.44% and 33.33%, respectively.

Current knowledge of the taxonomy and classification of representatives from the order Legionellales (Legionellaceae, Coxiellaceae) Phylum Pseudomonadota

Since the development of microbiology as a science, the identification, systematics and classification of microorganisms have been carried out based on the study of phenotypic characteristics. In the second half of the 20th century, after the discovery of the structure of DNA and polymerase chain reaction, the era of molecular biological research began in microbiology. Since 2002, the use of a complex of molecular biological and phylogenetic methods has been recommended as a guiding approach in the classification and taxonomy of prokaryotes, which has led to reclassification in some taxa. The representation of the taxonomy of Legionella pneumophila (order Legionellales, class Gammaproteobacteria) was formulated after the outbreak of legionnaires’ disease (legionellosis) in the USA in 1976. The description of the causative agent of Q-fever – Coxiella burnetii occurred 40 years earlier, but its classification and taxonomic status in the order Rickettsiales of the class Alphaproteobacteria were presented incorrectly based on the study of available phenotypic characteristics in the 1930s and 1950s. This determined the «fate» of C. burnetii and Q-fever for half a century, included in the list of rickettsiae and rickettsioses traditionally studied by rickettsiologists. As a result of the application of molecular biological methods in the 1990s, in the order Legionellales was replenished by several representatives of the order Rickettsiales, three representatives of which (C. burnetii, Rickettsiella grilli and Wolbachia persica) were moved to the class Gammaproteobacteria. Analysis of the 16S rRNA gene sequence led to the reclassification of Coxiella into a separate genus of gamma-proteobacteria of the phylum Proteobacteria (now Pseudomonadota) along with the genera Legionella, Francisella and Rickettsiella with representatives of which have the greatest phylogenetic relationship. Sequencing of the 16S rRNA gene of C. burnetii isolates from different geographical regions revealed only three nucleotide substitutions, indicating that the nucleotide sequences of these strains are closely related (the degree of homology is 99%), which confirms the phylogenetic uniformity of the genus Coxiella within a single species. A comparative analysis of the proteome of representatives of the order Legionellales and a phylodendrogramm constructed during the study of the main proteins of representatives of the genera Legionella, Coxiella, Acquicella and Rickettsiella (Diplorickettsia) allowed the formation of various clades confirming their monophyla. The C. burnetii genome encodes 24 similar components out of 27 involved in the pathogenesis of L. pneumophila by type IVB secretory system (type IVB secretory systems). Verification of the taxonomic position of C. burnetii is an example of the use of molecular biological methods to solve problems of taxonomy and classification of prokaryotes. It is advisable to use an integrated approach based on the application of «classical» methods of bacteriology and new molecular biological and phylogenetic methods, which will allow to obtain an objective understanding of the microorganisms associated with the human population.

Genetic structure and Rickettsia infection rates in Ixodes ovatus and Haemaphysalis flava ticks across different altitudes.

Ixodid ticks, such as Ixodes ovatus and Haemaphysalis flava, are important vectors of tick-borne diseases in Japan, such as Japanese spotted fever caused by Rickettsia japonica. This study describes the Rickettsia infection rates influenced by the population genetic structure of I.ovatus and H. flava along an altitudinal gradient. A total of 346 adult I. ovatus and 243 H. flava were analyzed for the presence of Rickettsia by nested PCR targeting the 17kDA, gltA, rOmpA, and rOmpB genes. The population genetic structure was analyzed utilizing the mitochondrial cytochrome oxidase 1 (cox1) marker. The Rickettsia infection rates were 13.26% in I. ovatus and 6.17% in H. flava. For I. ovatus, the global FST value revealed significant genetic differentiation among the different populations, whereas H. flava showed non-significant genetic differentiation. The cox1 I. ovatus cluster dendrogram showed two cluster groups, while the haplotype network and phylogenetic tree showed three genetic groups. A significant difference was observed in Rickettsia infection rates and mean altitude per group between the two cluster groups and the three genetic groups identified within I. ovatus. No significant differences were found in the mean altitude or Rickettsia infection rates of H. flava. Our results suggest a potential correlation between the low gene flow in I. ovatus populations and the spatially heterogeneous Rickettsia infection rates observed along the altitudinal gradient. This information can be used in understanding the relationship between the tick vector, its pathogen, and environmental factors, such as altitude, and for the control of tick-borne diseases in Japan.

A Rare Case of Rickettsia and Herpes Simplex Virus 1 Co-infection in a Male Patient with Meningoencephalitis

Herpes simplex viruses (HSVs) belong to the Herpesviridae family. Close contact is the primary mode of transmission for both HSV-1 and HSV-2, leading to a persistent lifelong infection. HSVs are widely recognized as causative agents of viral infections affecting the central nervous system, capable of presenting as both meningitis and encephalitis. Herpes simplex virus type 1 (HSV-1) is the predominant viral cause of encephalitis, accounting for the majority of cases. Here, a rare co-infection case of meningoencephalitis, associated with HSV-1 and rickettsia is described. A 42-year-old man presenting with non-remitting headache for 6 days, fever, sweating, and muscle aches was admitted to the Emergency Department. His Weil-Felix test was positive for Proteus OX2 indicating rickettsial infection. Therapy started promptly however patient’s condition deteriorated. Cerebrospinal fluid (CSF) analysis revealed lymphocytic pleocytosis, and elevated protein concentration. CSF molecular analysis was positive for HSV-1. His cranial MRI indicated cytotoxic edema and gyral enhancement at the right temporal lobe. He was administered acyclovir for 14 days during hospital stay and was successfully discharged. This case report highlights that HSV-1 meningoencephalitis can co-occur with rickettsia infection in immunocompetent individuals, and co-infection with other agents should always be considered to avoid the progression of the disease.

A clinical case series of Rickettsia spp. from southern Türkiye

Rickettsial infections should be considered in the presence of a maculopapular rash, especially in the endemic area with a history of tick bite. In this study, Rickettsia spp. infections of three cases will be mentioned. Three cases with positive Rickettsia spp immunofluorescent antibody serology were included in the study. Case-1 was a 17-year-old male patient, who had a history of tick bite one week before the admission was admitted with chest pain. He had tachycardia and a "tache noir" rash with a necrotic center in the area of the tick bite. Laboratory parameters showed lymphopenia, cardiac enzymes elevation. The patient’s serelogy of Rickettsia conorii IgM was 1/192 titer positive and IgG was negative. He hospitalized as acute Mediterranean Spotted Fever myocarditis. He recovered with doxycycline treatment. Case-2 was a nine-month-old girl presented with fever, rash and lymphadenomegaly on left axilla two weeks after the tick bite of her left arm. The rash was localized to the arm. R. slovaca and R. aeschlimannii serologies were detected 1/40 titer positive. After ciprofloxacin treatment her symptoms had dissapeared. Case-3 was a seven-year-old girl presented with fever reaching 39ºC for five days, myalgia and rash all over her body. She had scratched the tick from the scalp five days before the admission. Rickettsia conorii IgM serology was 1/768, IgG was 1/640 titer positive. She recovered after doxycycline treatment. Rickettsia spp. infections can lead to infections like myocarditis or the spotted fever group Rickettsiosis diseases. Complications can be prevented with early diagnosis and treatment.

Rickettsial Infection in Ticks from a National Park in the Cerrado Biome, Midwestern Brazil.

This study was carried out from February 2020 to September 2021 in Parque Nacional das Emas (PNE), a national park located in the Cerrado biome, midwestern Brazil, as well as in surrounding rural properties. Serum and tick samples were collected from dogs, terrestrial small mammals, and humans. Ticks were also collected from the environment. Dogs were infested with Rhipicephalus linnaei adults, whereas small mammals were infested by immature stages of Amblyomma spp., Amblyomma triste, Amblyomma dubitatum, and Amblyomma coelebs. Ticks collected from vegetation belonged to several species of the genus Amblyomma, including A. coelebs, A. dubitatum, Amblyomma naponense, Amblyomma sculptum, and A. triste. Two Rickettsia species were molecularly detected in ticks: Rickettsia parkeri in A. triste from the vegetation and a Rickettsia sp. (designated Rickettsia sp. strain PNE) in A. sculptum and A. triste collected from lowland tapirs (Tapirus terrestris). Based on short gltA gene fragments, this rickettsial organism showed 99.7-100% to Rickettsia tillamookensis. Seroreactivity to Rickettsia antigens was detected in 21.9% of dogs, 15.4% of small mammals, and 23.5% of humans. The present study reveals the richness of ticks and demonstrates the circulation of rickettsial agents in one of the largest conservation units in the Cerrado biome in Brazil. To our knowledge, this is the first report of a rickettsial phylogenetically related to R. tillamookensis in Brazil.

New tick records with notes on rickettsial infection from the wildlife of the state of Espírito Santo, southeastern Brazil

This work aimed to report ticks infesting the wildlife among 15 municipalities of the state of Espírito Santo between 2016 and 2021, within the Atlantic Forest biome of southeastern Brazil. A total of 576 tick specimens (187 males, 56 females, 149 nymphs, and 184 larvae) was collected from 41 species of wild vertebrates (two reptiles, nine mammals, and 30 birds). Ticks were identified by morphological or molecular methods into 18 species, being 12, four, one and one of the genera Amblyomma, Ixodes, Rhipicephalus and Ornithodoros, respectively. Amblyomma rotundatum was the only species collected from reptiles. Ticks collected from mammals were identified as Amblyomma brasiliense, Amblyomma calcaratum, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma nodosum, Amblyomma pacae, Amblyomma sculptum, Amblyomma varium and Rhipicephalus microplus. Amblyomma sculptum was the species found on the widest variety of hosts, collected from four mammal orders and five bird orders. Passeriformes birds were infested by Amblyomma fuscum, A. longirostre (also found on non- passerine birds), A. nodosum, Amblyomma parkeri, Amblyomma romarioi, A. varium and Ixodes loricatus. An adult female of Ixodes rio was collected from a Piciformes bird. Seabirds of the order Procellariiformes were infested by Ixodes percavatus sensu lato and Ixodes uriae. The argasid Ornithodoros capensis was collected from an offshore metallic platform that was used by Suliformes seabirds. Rickettsial agents of the spotted fever group, Rickettsia amblyommatis and Rickettsia sp. strain Pampulha, were detected in the ticks A. longirostre [from the Paraguayan hairy dwarf porcupine (Coendou spinosus)] and A. dubitatum [from the capybara (Hydrochoerus hydrochaeris)], respectively. The following nine tick species are reported for the first time in Espírito Santo state: A. calcaratum, A. fuscum, A. pacae, A. parkeri, A. romarioi, I. loricatus, I. rio, I. uriae, and O. capensis. Although it is also the first report of I. uriae in Brazil, we do not consider it established in the country. Multiple new tick-host associations are reported in the present study.

Demographic and Clinical Profiles of PCR Positive Rickettsia felis Infected Patients at A Tertiary Care Hospital in Bangladesh

Background: Rickettsial infections remain relatively unexplored, under recognized and under reported due to a lack of awareness and limited access to diagnosis. Objective: The purpose of the present study was to evaluate the demographic and clinical profile of PCR positive Rickettsia felis infected patients attended at a tertiary care hospital. Methodology: This cross-sectional study was conducted in the Department of Microbiology at Mymensingh Medical College, Mymensingh, Bangladesh from July 2013 to June 2014 for duration of one year. Patients with fever (102° to 104°F) more than 15 days of any age and gender, not responding to commonly used antibiotics and any other additional complaints and clinical features including headache, rash, lymphadenopathy or myalgia and eschars on the skin were included in this study. Patients with evident cause of fever like malaria diagnosed by blood smear or immunochromatography were excluded from the study. Blood was collected according to blood collection guidelines. PCR from blood was performed using standard protocol with specific primers to detect Rickettsia up to species level. Results: A total number of 50 respondents were recruited after fulfilling the inclusion and exclusion criteria. Among them 21(42%) cases were PCR positive. Among 21 PCR positive cases, the predominant age group was more than 15 to 30 years which was 11(52.4%), female patients were predominant than male patients which was 11(52.0%). All the cases with Rickettsial infection had fever 21(100.0%). Other associated features like headache was most commonly noticed in 10(47.6%) cases followed by body-ache, Cough and rash which was 7(33.3%) cases, 5(23.8%) cases and 1/21 (4.7%) cases respectively. Conclusion: This study demonstrated high prevalence of Rickettsia felis infection in patients in Bangladesh with unidentified febrile illness and suggests that this infection is endemic to the north-central area of this country. Females are more prone to get infected and most commonly noticed associated features was headache. Bangladesh Journal of Medical Microbiology, July 2023;17 (2):71-76

601. Clinical Presentation and Pregnancy Outcomes of PCR-Proven Rickettsial Infections in Pregnant Women

Abstract Background Rickettsial infections are endemic zoonoses found worldwide. Spotted fever (R. conorii) and murine typhus (R. typhi) cause a spectrum of diseases from mild to multi-organ failure and death. Diagnosis and treatment of rickettsial infections in pregnancy are challenging, and little is known about pregnancy outcomes. We describe a cohort of PCR-proven rickettsial infections in pregnant women in Israel. Methods Whole blood samples were taken from pregnant women with acute febrile illness. Samples were subjected to DNA extraction and a general set of primers and probe was used to identify Rickettsia spp. by RT-PCR. Results In 2020, 12 pregnant women were diagnosed by PCR with rickettsial disease. Upon presentation, the mean age was 26 (18-39) years, and the mean gestational age was 31 (22-40) weeks. The number of days until diagnosis was established was 5 (2-10). The most common symptom other than fever was headache (11/12), only half presented with a rash. Most women developed elevated liver enzymes (11/12), and 2/12 had thrombocytopenia. Interestingly, 7/12 presented with respiratory symptoms, and 2/12 had myocardial involvement manifested as either elevated myocardial enzymes or ventricular dysfunction on echocardiogram. All women received Azithromycin as a first-line anti-rickettsial antibiotic, while 5 women were switched to Doxycycline due to disease severity. Defervescence within 24 hours after a single antibiotic dose was seen in 8/12 of women. Only 1/12 were delivered preterm, and the mean birth weight was 3000g. Serologic assays were available for 11/12 women, confirming murine typhi in 5/12 cases, and unidentified rickettsial infection in 3/12. Species identification wasn't available using PCR alone. Conclusion Molecular assays are a valuable tool for real-time diagnosis of rickettsial infections in pregnant women, allowing for a rapid targeted antibiotic treatment with good clinical outcomes for both mother and neonate. Unusual rates of respiratory and myocardial involvement were observed in our cohort, suggesting a possible specific pregnancy-related complication. Disclosures All Authors: No reported disclosures

1775. Predictor Factors Of Severe Forms Of Rickettsial Infections

Abstract Background Rickettsial infections usually mimic benign viral infection due to similarities in clinical symptoms. However, severe forms and complications might occur changing therfore the prognosis of the disease. We aimed to study the predictor factor of severe forms of rickettsial infections. Methods We conducted a retrospective study including all patients hospitalized in the infectious diseases department for rickettsiosis. The diagnosis was confirmed by serologies (seroconversion) and/or positive polymerase chain reaction for Rickettsia in skin biopsy. Severe forms included cases with acute respiratory distress syndrome, myocarditis, meningitis, meningoencephalitis, renal failure or septic shock. Results We encountered 472 cases among which 98 cases were severe (20.8%). Median age was 43[25-60] years among severe forms and 38[24-53] years among non-severe forms (p=0.132). Maculopapular skin rash (56.7% vs 88% ; p< 0.001), arthralgia (56.1% vs 77.3% ; p< 0.001) and eschar (16.3% vs 27% ; p=0.029) were significantly less frequent among severe forms. Meningeal syndrome (34.7% vs 8.3% ; p< 0.001), vomiting (56.1% vs 41.8% ; p=0.011) and cough (28.6% vs 13.9% ; p=0.001) were significantly more frequent among severe forms. Leukocytosis was significantly more frequent among severe forms (35.7% vs 20.6% ; p=0.002). The optimal cut-off value of white blood cell count for predicting severe forms was 7595/mm3, with a sensitivity of 61.9% and a specificity of 59.7%. The area under the curve was 0.622 and the 95% confidence interval ranged from 0.558 to 0.686. Elevated C-reactive protein levels (66.3% vs 65.5%; p=0.879) and accelerated erythrocyte sedimentation rate (36.7% vs 40.1%; p=0.543) were noted among severe and non-severe forms of rickettsiosis, with no significant difference. Conclusion The revealing symptoms of severe forms were characterized by the presence of vomiting, cough and meningeal syndrome, in the absence of the typical maculopapular skin rash and eschar. Leukocytosis was more frequent among severe forms of rickettsiosis. The diagnosis of severe forms should be kept in mind in order to promptly initiate the adequate treatment. Disclosures All Authors: No reported disclosures

Metagenomic next-generation sequencing for diagnosis of infectious encephalitis and meningitis: a retrospective study of 90 patients

ABSTRACT Background Infections of the central nervous system (CNS) are potentially life-threatening and can cause serious morbidity. We evaluated the clinical value of metagenomic next-generation sequencing (mNGS) in the diagnosis of infectious encephalitis and meningitis and explored the factors affecting the results of mNGS. Methods Patients with suspected cases of encephalitis or meningitis who presented in Northern Jiangsu People’s Hospital from 1 March 2018 to 30 September 2022 were collected. Demographic, historical, and clinical information were obtained, and cerebrospinal fluid (CSF) samples were treated with mNGS. The pathogen was identified using National Center for Biotechnology Information (NCBI) GenBank sequence data. Results Ninety-six patients were screened and finally 90 subjects enrolled. Of the 90 enrolled cases, 67 (74.4%) were diagnosed with central nervous system infections, which included 48 cases (71.6%) of viral infection, 11 (12.2%) of bacterial infection, 5 (7.5%) of mycobacterium tuberculosis, 2 (3.0%) of fungal infection, and 1 (1.5%) of rickettsia infection. From these cases, mNGS identified 40 (44.4%) true-positive cases, 3 (3.3%) false-positive case, 22 (24.4%) true-negative cases, and 25 (27.8%) false-negative cases. The sensitivity and specificity of mNGS were 61.5% and 88%, respectively. mNGS of CSF could show a higher positive rate in patients with marked CSF abnormalities, including elevated protein concentrations and monocyte counts. Conclusion mNGS of CSF is an effective method for detecting infectious encephalitis and meningitis, and the results should be analyzed combined with conventional microbiological testing results.

Epidemiology of scrub typhus and other rickettsial infections (2018-22) in the hyper-endemic setting of Mizoram, North-East India.

In the past decade, scrub typhus cases have been reported across India, even in regions that had no previous history of the disease. In the North-East Indian state of Mizoram, scrub typhus cases were first recorded only in 2012. However, in the last five years, the state has seen a substantial increase in the scrub typhus and other rickettsial infections. As part of the public health response, the Mizoram Government has integrated screening and line listing of scrub typhus and other rickettsial infections across all its health settings, a first in India. Here we detail the epidemiology of scrub typhus and other rickettsial infections from 2018-2022, systematically recorded across the state of Mizoram. The line-listed data positive for scrub typhus and other rickettsial infections identified by rapid immunochromatographic test and/or Weil-Felix test from 2018-22 was used for the analysis. During this period, 22,914 cases of rickettsial infections were recorded, out of which 19,651 were scrub typhus cases. Aizawl is the worst affected, with 10,580 cases (46.17%). The average incidence of rickettsial infections is 3.54 cases per 1000 persons-year, and the case fatality rate is 0.35. Only ∼2% of the reported scrub typhus cases had eschar. Multivariate logistic regression analysis indicate patients with eschar (aOR = 2.5, p<0.05), occupational workers [farmers (aOR:3.9), businessmen (aOR:1.8), construction workers (aOR:17.9); p<0.05], and children (≤10 years) (aOR = 5.4, p<0.05) have higher odds of death due to rickettsial infections. The integration of systematic surveillance and recording of rickettsial diseases across Mizoram has shed important insights into their prevalence, morbidity, and mortality. This study underscores the importance of active surveillance of rickettsial infections across India, as the burden could be substantially higher, and is probably going undetected.

Rickettsial Infection in the COVID-19 Era: The Correlation between the Detection of Rickettsia aeschlimannii in Ticks and Storytelling Photography of a Presumable Human Rickettsiosis Case.

Rickettsia aeschlimannii infection is an emerging human tick-borne disease with only a few recorded cases. We reported a presumable autochthonous case of rickettsiosis in an Italian cattle breeder associated with a Hyalomma marginatum bite. Rickettsia aeschlimannii DNA was detected in both the tick specimen from the patient and the grazing cattle close to his farm.

S3744 Typhus in Texas: Rickettsial Infection as a Cause of Elevated Liver Enzymes

S3744 Typhus in Texas: Rickettsial Infection as a Cause of Elevated Liver Enzymes

Diagnosis and Management of Rickettsial Infections among Febrile Patients Attending in Inpatients and Outpatient Department in a District Hospital in Bangladesh

Background: Numerous obligatory intracellular bacteria from the Alphaproteobacteria genus Rickettsia can cause rickettsial infection. The most prevalent newly emerging and reemerging diseases are rickettsial infections. Objectives: The aim of the study was diagnosis and management of rickettsial infections among febrile patients attending in inpatient and outpatient department in a district hospital in Bangladesh. Methods: This cross-section observational study was carried out in the 250 Beded District Hospital, Joypurhat. The duration of the period from March 2022 to February 2023. A total of 250 patients participated in the study. Both male and female with any age, patients with elevated body temperature, headache, malaise, rash, nausea, and vomiting and gave consent to be included in the study. Severely ill patients, not willing to participate were excluded from the study. Weil Felix test was used in this study and a titre of 1:80 was considered to be positive. Statistical evaluation of the results used to be obtained via the use of a window-based computer software program devised with Statistical Packages for Social Sciences (SPSS-24). Results: The mean age of the patients was 39 ± 1.9. 8% of the patients had ≤18 years of age. 16% were within the age group of 19-29 years, 28% were within the age group of 30-39 years, 24% were within the age group of 40-49 years, 14.4% were within the age group of 50-59 years and 9.6% were ≥60 years and 52% of the patients were male. 100% of the respondents had fever, 20% had generalized weakness, 15.2% had headache, 16% had cough and cold, 24% had body ache, 8% had vomiting and abdominal pain respectively, 4% had per nasal watery discharge, 36% had rash, 16% had nausea, 24% had anorexia and 4% had other symptoms. CBC &amp; ESR and Weil Felix test were the most common (100%) investigation among the patients, Urine R/M/E in 68%, serum creatinine in 18%, USG of W/A in 15%, CRP in 18%, PBF in 7, Urine C/S in 10%, S. Electrolytes in 4% cases. We found 90 Rickettsial Infection positive patients. Doxycycline and Paracetamol and Esomeprazole were prescribed to all patients 90(100%) and followed by Linagliptin+Metformin to 20(22.22%), Glimipiride to 19(21.11%), Azithromycin to 18(20%) and Domperidon to 10(1.11%), Montelukast 9 (10%), Pantoprazole to 8(8.89%), Rupatadine to 7(7.77%), Ondansetron to 6(6.67%), Tiemonium to 5 5.57%), Fexofenadin to4(4.44%) and other treatment along with the prescribed medicines was given to 40(44.44%) patients. Authors studied the response of Doxycycline which showed 85(94.44%) cases improved within 48 hours of start of treatment. Remaining 5(5.55%) cases showed delayed response due to late presentation. Conclusion: Rickettsial illness is inextricably linked to the sociocultural life of the majority of metropolitan residents. However, a lack of medical facilities and qualified doctors makes it challenging to identify rickettsial disease in febrile patients. It's important to make an early diagnosis when treating rickettsial illness.

Evidence on the prevalence of emerging and re-emerging tick- and flea-borne rickettsial agents in acute encephalitis syndrome endemic areas of northeast Uttar Pradesh, India.

Outbreaks of acute encephalitis syndrome (AES) with unknown aetiology are reported every year in Gorakhpur district, Uttar Pradesh, India, and Orientia tsutsugamushi, the rickettsial pathogen, responsible for scrub typhus has been attributed as the primary cause of AES problem. However, information on the prevalence of other rickettsial infections is lacking. Hence, this study was carried out to assess any occurrence of tick- and flea-borne rickettsial agents in villages reporting AES cases in this district. In total, 825 peridomestic small mammals were trapped, by setting 9254 Sherman traps in four villages with a trap success rate of 8.9%. The Asian house shrew, Suncus murinus, constituted the predominant animal species (56.2%) and contributed to the maximum number (87.37%) of ectoparasites. In total, 1552 ectoparasites comprising two species of ticks and one species each of flea and louse were retrieved from the trapped rodents/shrews. Rhipicephalus sanguineus, the brown dog tick, was the predominant species retrieved from the trapped rodents/shrews, and the overall infestation rate was 1.75 per animal. In total, 4428 ectoparasites comprising five tick species, three louse species and one flea species were collected from 1798 domestic animals screened. Rhipicephalus microplus was the predominant tick species collected from the domestic animals. The cat flea, Ctenocephalides felis, constituted 1.5% of the total ectoparasites. Of all the ectoparasite samples (5980) from domestic animals and rodents, tested as 1211 pools through real-time PCR assays, 64 pools were positive for 23S rRNA gene of rickettsial agents. The PCR-positive samples were subjected to multi-locus sequence typing (MLST). In BLAST and phylogenetic analysis, the ectoparasites were found to harbour Rickettsia asembonensis (n = 9), Rickettsia conorii (n = 3), Rickettsia massiliae (n = 29) and Candidatus Rickettsia senegalensis (n = 1). A total of 22 pools were detected to have multiple rickettsial agents. The prevalence of fleas and high abundance of tick vectors with natural infections of rickettsial agents indicates the risk of transmission of tick- and flea-borne rickettsial diseases in rural villages of Gorakhpur. Further epidemiological studies are required to confirm the transmission of these agents to humans.

Molecular detection of Candidatus Ehrlichia pampeana (Rickettsiales: Anaplasmataceae) in Haemaphysalis juxtakochi (Acari: Ixodidae) from central Argentina.

The aim of this study was to report the first detection of Candidatus Ehrlichia pampeana in Haemaphysalis juxtakochi from Argentina. Free-living ticks were collected from vegetation by drag-flag method on five sample sites in Entre Ríos Province, central Argentina, belonging to the Espinal Phytogeographic Province. Molecular detection of order Rickettsiales agents was performed using gltA (Rickettsia spp.), 16S rRNA and groEL (Anaplasmataceae) genes as targets. A total of 67 ticks of Amblyomma aureolatum (20 nymphs and 4 adults), Amblyomma dubitatum (15 nymphs) and Haemaphysalis juxtakochi (24 nymphs and 4 adults) were collected. While all tested ticks were negative for Rickettsia spp., and Anaplasmataceae agents could neither be detected in A. aureolatum nor in A. dubitatum, Candidatus Ehrlichia pampeana was detected in one male of H. juxtakochi. DNA sequences of this microorganism (16S rDNA and groEL) are related to sequences of Ehrlichia ewingii. The findings of the current study represent the first report of this Ehrlichia strain for Argentina.