Urgent call for attention to diabetes-associated hospital infections

In this editorial,we discuss the recent article by Zhao et al published in the World Journal of Diabetes,which highlights the importance of recognizing the risk indicators associated with diabetes mellitus(DM).Given the severe implications of healthcare-associated infections(HAIs)in hospitalized individuals-such as heightened mortality rates,prolonged hospitalizations,and increased costs-we focus on elucidating the connection between DM and nosocomial infections.Diabetic patients are susceptible to pathogenic bacterial invasion and subsequent infection,with some already harboring co-infections upon admission.Notably,DM is an important risk factor for nosocomial urinary tract infections and surgical site infections,which may indirectly affect the occurrence of nosocomial bloodstream infections,especially in patients with DM with poor glycemic control.Although evidence regarding the impact of DM on healthcare-associated pneumonias remains inconclusive,attention to this potential association is warranted.Hospitalized patients with DM should prioritize meticulous blood glucose management,adherence to standard operating procedures,hand hygiene practices,environmental disinfection,and rational use of drugs during hospitalization.Further studies are imperative to explore the main risk factors of HAIs in patients with DM,enabling the development of preventative measures and mitigating the occurrence of HAIs in these patients.

Community-acquired multidrug-resistant pneumonia,bacteraemia,and infective endocarditis:A case report

BACKGROUND The prevalence of multidrug-resistant(MDR)bacteria has increased globally,with extensive drug-resistant(XDR)bacteria posing a threat to patients.CASE SUMMARY This case report describes a young man admitted for suspected tropical fever infections who experienced rapid deterioration in health.Despite negative results for tropical fever infections,he had neutrophilic leucocytosis,acute kidney injury,and chest imaging findings suggestive of bilateral consolidations.On day two,he was diagnosed with infective endocarditis with possible rheumatic heart disease and MDR methicillin-resistant Staphylococcus aureus bacteraemia,and communityacquired pneumonia.Despite treatment with broad-spectrum antibiotics,he did not respond and succumbed to death on day five.CONCLUSION This case highlights that clinicians/public should be aware of MDR communityacquired pneumonia,bacteraemia,and endocarditis which ultimately culminate in high rates of morbidity and mortality.Early identification of pathogenic strain and prompt antibiotic treatment are a mainstay for the management and prevention of early fatalities.Simultaneously,route cause analysis of communityacquired MDR/XDR pathogens is a global need.

Integrating host biological and ecological variables to predict probability of haemosporidian infection in raptors

Variations in host traits that influence their exposure and susceptibility may impact probability of vector-transmitted diseases.Therefore,identifying the predictors of infection probability is necessary to understand the risk of disease outbreaks during expanding environmental perturbation.Here,we conducted a large survey based on microscopic examination and molecular analysis of haemosporidian parasite infection in raptors rescued at the Beijing Raptor Rescue Centre.Combining these data with biological and ecological variables of the raptors,we determined predictors that affect the probability of haemosporidian infection using generalized linear mixed models and multimodel inference.Our results showed that infection probability exhibited considerable variation across host species in raptors,and body mass,sex,and evolutionary history played relatively weaker roles in driving infection probability.Instead,activity pattern,age,geographic range size,migration distance,and nest type were important predictors of the probability of haemosporidian infection,and the role of each predictor differed in the three main haemosporidian genera(Plasmodium,Haemoproteus,and Leucocytozoon).This macro-ecological analysis will add to our understanding of host traits that influence the probability of avian haemosporidian infection and will help inform risk of emerging diseases.

Thoracic spine infection caused by Pseudomonas fluorescens:A case report and review of literature

BACKGROUND The clinical incidence of spinal infection is gradually increasing,and its onset is insidious,easily leading to missed diagnosis and misdiagnosis,which may lead to serious complications such as nervous system dysfunction,spinal instability and/or deformity,and cause a huge burden on society and families.Early identification of the causative agent and precision medicine will greatly reduce the suffering of patients.At present,the main pathogenic bacteria that cause spinal infection are Staphylococcus aureus,Streptococcus,Pneumococcus,Escherichia coli,and Klebsiella.There are no reports of spinal infection caused by Pseudomonas fluorescens.CASE SUMMARY We report a 32-year-old female patient with spinal infection.She presented with flank pain,initially thought to be bone metastases or bone tuberculosis,and had a family background of tumors.Her clinical features and changes in imaging and laboratory tests led to the suspicion of thoracic spine infection.Histopathology of the lesion showed inflammation,tissue culture of the lesion was negative several times,and the possible pathogen-Pseudomonas fluorescens was found after gene sequencing of the lesion.The patient recovered completely after a full course of antibiotic treatment.CONCLUSION This report increases the range of pathogens involved in spinal infections,highlights the unique advantages of gene sequencing technology in difficult-todiagnose diseases,and validates conservative treatment with a full course of antibiotics for spinal infections without complications.

Knowledge of Hospital Acquired Infections (HAIs) among Medical Students in a Tertiary Hospital in Jos North Local Government Area, Plateau State, Nigeria

Background: Hospital Acquired Infections (HAIs) remain a common cause of death, functional disability, emotional suffering and economic burden among hospitalized patients. Knowledge of HAIs is important in its prevention and control. This study seeks to assess the knowledge of Hospital Acquired Infections (HAIs) among medical students in a Tertiary Hospital in Jos North Local Government Area, Plateau State, Nigeria. Methods: This was a descriptive cross-sectional study done in October 2019 among clinical medical students using a Multistage sampling technique. Data was collected using a self-administered structured questionnaire and analyzed using the IBM SPSS 20 (Statistical Package for the Social Sciences). Ethical approval was granted by Bingham University Teaching Hospital, Ethics Committee, Jos, Plateau State. Results: A total of 219 students in the clinical arm of the College of Medicine and Health Sciences were selected. A higher proportion (97.7%) of respondents knew about Hospital Acquired Infections and 85.4% knew that Hospital Acquired infections occur in the hospital, and (86.3%) considered patients contagious with half (58.9%) considered patients as the most important source of HAIs, followed by care givers (13.2%), then doctors including medical students and interns (10.0%) and lastly nurses (8.7%). The majority of respondents (70.8%) considered Surgical Wound Infections to be the most commonly occurring HAI, followed by UTIs (69.9%), RTIs (61.2%), BSIs (37.0%) and others (0.9%). The clinical thermometer was the instrument that most commonly transmits HAIs (82.6%), then followed by stethoscope (62.1%), white coats (53.9%), and blood pressure cuff (51.1%). Most respondents knew the infectious substances, like blood (96.3%), nasal discharge (82.6%), saliva (85.3%), and faeces (79.4%) transmitted HAIs, 72.6% of the respondents said that they were aware of the recommended hand washing techniques by WHO. Conclusion: The majority of students 91.3% had good knowledge while 8.7% had poor knowledge of HAIs. Lower classes had more respondents with poor knowledge. This finding was statistically significant (p = 0.002, Chi-square 12.819). Students are encouraged to keep up the level of knowledge they have about HAIs. These students can help improve the knowledge of those whose knowledge level is low. Government and NGOs should support sponsorship for capacity-building events targeted at HAIs for healthcare workers and medical students.

Micro-power negative pressure wound technique reduces risk of incision infection following loop ileostomy closure

BACKGROUND Prophylactic loop ileostomy is an effective way to reduce the clinical severity of anastomotic leakage following radical resection of rectal cancer.Incisional surgical site infection(SSI)is a common complication after ileostomy closure.AIM To evaluate the efficacy and safety of the micro-power negative pressure wound technique(MPNPWT)in preventing incisional SSI.METHODS This was a prospective,randomized controlled clinical trial conducted at a single center.A total of 101 consecutive patients who underwent ileostomy closure after rectal cancer surgery with a prophylactic ileostomy were enrolled from January 2019 to December 2021.Patients were randomly allocated into an MPNPWT group and a control group.The MPNPWT group underwent intermittent suturing of the surgical incision with 2-0 Prolene and was covered with a micro-power negative pressure dressing.The surgical outcomes were compared between the MPNPWT(n=50)and control(n=51)groups.Risk factors for incisional SSI were identified using logistic regression.RESULTS There were no differences in baseline characteristics between the MPNPWT(n=50)and control groups(n=51).The incisional SSI rate was significantly higher in the control group than in the MPNPWT group(15.7%vs 2.0%,P=0.031).However,MPNPWT did not affect other surgical outcomes,including intra-abdominal complications,operative time,and blood loss.Postoperative hospital stay length and hospitalization costs did not differ significantly between the two groups(P=0.069 and 0.843,respectively).None of the patients experienced adverse effects of MPNPWT,including skin allergy,dermatitis,and pain.MPNPWT also helped heal the infected incision.Our study indicated that MPNPWT was an independent protective factor[odds ratio(OR)=0.005,P=0.025)]and diabetes was a risk factor(OR=26.575,P=0.029)for incisional SSI.CONCLUSION MPNPWT is an effective and safe way to prevent incisional SSI after loop ileostomy closure.

Improving treatment plan and mental health in children with abdominal infection for broad-spectrum bacterial infections

BACKGROUND Pediatric abdominal infection is a common but serious disease that requires timely and effective treatment.In surgical treatment,accurate diagnosis and rational application of antibiotics are the keys to improving treatment effects.AIM To investigate the effect of broad-spectrum bacterial detection on postoperative antibiotic therapy.METHODS A total of 100 children with abdominal infection who received surgical treatment in our hospital from September 2020 to July 2021 were grouped.The observation group collected blood samples upon admission and sent them for broad-spectrum bacterial infection nucleic acid testing,and collected pus or exudate during the operation for bacterial culture and drug sensitivity testing;the control group only sent bacterial culture and drug sensitivity testing during the operation.RESULTS White blood cell count,C-reactive protein,procalcitonin,3 days after surgery,showed better postoperative index than the control group(P<0.05).The hospital stay in the observation group was significantly shorter than that in the control group.The hospitalization cost in the observation group was significantly lower than that in the control group,and the difference between the two groups was statistically significant(P<0.05).CONCLUSION Early detection of broad-spectrum bacterial infection nucleic acids in pediatric abdominal infections can help identify pathogens sooner and guide the appropriate use of antibiotics,improving treatment outcomes and reducing medical costs to some extent.

The Place of Nursing Theory in the Management of Post-Operative Infections in a Hospital Environment: Case of Cibitoke District Hospital

Introduction: Post-operative infections, such as surgical site infections (SSIs), are a significant concern in healthcare settings. Nurses play a crucial role in the prevention and management of these infections. The use of nursing theory could contribute to the prevention of SSIs. The aim of this study was to evaluate the role of nursing theory in the management of surgical site infections (SSIs) in a hospital environment. Method: A cross-sectional study was conducted using descriptive and analytical methods to assess the role of nursing theory in the management of Post-operative infections (POI) in a hospital setting in October 2023. The study population consisted of nurses working in the Surgery, Emergency, and Maternity units at Cibitoke District Hospital. A sample size of 71 nurses working full or part time in the Surgery were invited to participate in this study. A questionnaire was used to collect the data, and SPSS version 21.0 software was used for analysis. Results: The study found that nursing theory did not have any statistically significant place in the management of POI (p-value = 0.523). However, the results showed that experience was the only significant factor influencing the management of POI (p-value = 0.004). This is explained by the analysis of the net effects of the explanatory variable where we noticed that those who had more experience were more likely to manage post-operative infections. The participants’ knowledge regarding nursing theory in the management was poor as they scored less than 30% in all the variables used to measure their knowledge. Conclusion: The study revealed that nurses’ knowledge of nursing theories and their applications in the management of SSIs was poor. Continuing professional development, curriculum review, and in-service training were highly recommended.

The Impact of Optimizing Details in the Operating Room on the Level of Knowledge, Attitude, and Practice of Hospital Infection Prevention and Control by Surgeons, as Well as the Effectiveness of Infection Control

Objective: This paper aims to explore the impact of optimizing details in the operating room on the level of knowledge, attitude, and practice of hospital infection prevention and control by surgeons, as well as the effectiveness of infection control. Methods: From January 2022 to June 2023, a total of 120 patients were screened and randomly divided into a control group (routine care and hospital infection management) and a study group (optimizing details in the operating room). Results: Significant differences were found between the two groups in the data of surgeons’ level of knowledge, attitude, and practice in hospital infection prevention and control, infection rates, and nursing satisfaction, with the study group showing better results (P Conclusion: The use of optimizing details in the operating room among surgeons can effectively improve surgeons’ level of knowledge, attitude, and practice in hospital infection prevention and control, reduce infection occurrence, and is worth promoting.

Application of PDCA in improving hand hygiene compliance and nosocomial infection quality in orthopedics

Objective:To explore the effect of the Plan-Do-Check-Action(PDCA)cycle on hand hygiene and nosocomial infection quality of or thopedic medical staff.Methods:The whole year of 2021 was selected to monitor the quality of hand hygiene and hospitalization.Follow-up monitoring and real-time recording during the period of morning shift and medical operation concentration time,and compare the compliance of hand hygiene before and after implementation,and evaluate the quality of nosocomial infection.Results:The hand hygiene compliance of doctors and nurses in stage P was 82%.The compliance of medical staff in stage D was 93%.The compliance of stage C was 94%and that of stage A was 95%.The quality score of hospital self-examination nosocomial infection was also significantly increased.Conclusions:The PDCA management cycle can effectively improve the compliance of hand hygiene and the nosocomial infection quality,which is wor thy of circulatory application in or thopedic nosocomial infection quality control,especially improving the quality of hand hygiene.

Infective Endocarditis in Chronic Hemodialysis Patients: Specificities and Therapeutic Management

Infective endocarditis (IE) is a frequent complication in chronic hemodialysis patients (CHD). The repeated placement and manipulation of central venous catheters, underlying valvulopathies, and immunosuppression are the main predisposing factors for these patients to develop IE. We aimed to highlight the clinical and microbiological specificities of IE in CHD patients, detail the therapeutic management in these patients and identify the risk factors for in-hospital mortality. We included 28 CHD patients in whom the diagnosis of IE was established according to modified Duke criteria. The mean age was 47 ± 17 years. Among them, 57% were hypertensive and 39% were diabetic. The average duration of hemodialysis was 3.5 ± 7 years. The vascular access was a tunnelled jugular catheter, arteriovenous fistula, and temporary catheter in 54%, 28%, and 18% of patients, respectively. Half of the patients presented with heart failure at admission. Methicillin-sensitive Staphylococcus is the most commonly implicated pathogen. Transthoracic echocardiography revealed vegetation in all patients. In 60% of cases, the lesion is located on the mitral valve, and in 35% it is on the tricuspid valve. Patients initially received empirical antibiotic therapy, which was adjusted according to bacteriological results. Valve surgery was indicated in 12 patients, with aortic valve replacement being the most performed procedure followed by tricuspid annuloplasty. The in-hospital mortality rate was 32%. Factors associated with mortality were severe mitral insufficiency (p = 0.036), heart failure (p = 0.043), and the presence of Methicillin-resistant Staphylococcus in blood cultures (p = 0.047). IE is a complication with high morbidity and mortality. Its increasing incidence, specificities in chronic CHD patients, and the complexity of its management require a rigorous preventive strategy. A multidisciplinary collaboration between nephrologists, infectious disease specialists, cardiologists, and surgeons is crucial to optimize therapeutic management.

Exploration of Therapeutic Measures and Clinical Efficacy for Recurrent Respiratory Infections in Children

Objective:To explore the treatment strategies and clinical effects for recurrent respiratory infections in children.Methods:From May 2022 to May 2024,100 pediatric patients with recurrent respiratory infections were selected in this study and evenly divided into two groups.The control group(50 patients)was treated with conventional therapy supplemented with budesonide,while the observation group(50 patients)received pidotimod treatment in addition to the control group’s treatment.Subsequently,the duration of clinical symptom improvement,respiratory function enhancement,serological index changes,reinfection status,and parental satisfaction were compared between the two groups.Results:In terms of clinical symptoms,the observation group showed significantly shorter durations of fever reduction,cough relief,tonsil swelling reduction,and disappearance of fine wet rales compared to the control group(average reduction times were 1.6 days,2.3 days,2.1 days,and 1.9 days,respectively,P<0.05).Regarding respiratory function,the observation group experienced a 12%increase in peak expiratory flow rate variability,a 0.6-liter increase in lung capacity,a 0.7-liter increase in forced lung capacity,and a 0.5-liter increase in forced expiratory volume in the first second after treatment,all significantly higher than the control group(P<0.05).Serological testing revealed that interferon-γand interleukin-2 levels increased by 15%and 18%,respectively,while interferon-α,interleukin-5,and interleukin-4 levels decreased by 10%,12%,and 9%,respectively,in the observation group,showing significant differences compared to the control group(P<0.05).Additionally,the reinfection rate in the observation group(10%)was significantly lower than that in the control group(30%),with an average reduction of two reinfections within one year and a 3.2-day shorter infection control time(P<0.05).In terms of parental satisfaction,the observation group achieved 95%,significantly higher than the 70%in the control group(P<0.05).Conclusion:The addition of pidotimod to conventional therapy for pediatric patients with recurrent respiratory infections can significantly alleviate clinical symptoms,promote the recovery of respiratory function,regulate serological indicators,effectively reduce the risk of reinfection,and improve parental satisfaction.This method deserves widespread clinical application.

Mathematical Modeling of the Co-Infection Dynamics of HIV and Tuberculosis Incorporating Inconsistency in HIV Treatment

A non-linear HIV-TB co-infection has been formulated and analyzed. The positivity and invariant region has been established. The disease free equilibrium and its stability has been determined. The local stability was determined and found to be stable under given conditions. The basic reproduction number was obtained and according to findings, co-infection diminishes when this number is less than unity, and persists when the number is greater than unity. The global stability of the endemic equilibrium was calculated. The impact of HIV on TB was established as well as the impact of TB on HIV. Numerical solution was also done and the findings indicate that when the rate of HIV treatment increases the latent TB increases while the co-infected population decreases. When the rate of HIV treatment decreases the latent TB population decreases and the co-infected population increases. Encouraging communities to prioritize the consistent treatment of HIV infected individuals must be emphasized in order to reduce the scourge of HIV-TB co-infection.

Klebsiella pneumoniae infections after liver transplantation:Drug resistance and distribution of pathogens,risk factors,and influence on outcomes

BACKGROUND Liver transplantation(LT)is the only curative treatment for end-stage liver disease.However,LT recipients are susceptible to infection,which is the leading cause of early mortality after LT.Klebsiella pneumoniae infections(KPIs)in the bloodstream are common in LT recipients.We hypothesized that KPIs and carbapenemresistant Klebsiella pneumoniae(CRKP)infections may affect the outcomes of LT recipients.AIM To assess KPI incidence,timing,distribution,drug resistance,and risk factors following LT and its association with outcomes.METHODS This retrospective study included 406 patients undergoing LT at The Third Xiangya Hospital of Central South University,a tertiary hospital,from January 2015 to January 2023.We investigated the risk factors for KPIs and assessed the impact of KPIs and CRKP infections on the prognosis of LT recipients using logistic regression analysis.RESULTS KPI incidence was 7.9%(n=32),with lung/thoracic cavity the most frequent site of infection;the median time from LT to KPI onset was 7.5 d.Of 44 Klebsiella pneumoniae isolates,43(97.7%)and 34(77.3%)were susceptible to polymyxin B or ceftazidime/avibactam and tigecycline,respectively;>70%were resistant to piperacillin/tazobactam,ceftazidime,cefepime,aztreonam,meropenem,and levofloxacin.Female sex[odds ratio(OR)=2.827,95%confidence interval(CI):1.256-6.364;P=0.012],pre-LT diabetes(OR=2.794,95%CI:1.070-7.294;P=0.036),day 1 post-LT alanine aminotransferase(ALT)levels≥1500 U/L(OR=3.645,95%CI:1.671-7.950;P=0.001),and post-LT urethral catheter duration over 4 d(OR=2.266,95%CI:1.016-5.054;P=0.046)were risk factors for KPI.CRKP infections,but not KPIs,were risk factors for 6-month all-cause mortality post-LT.CONCLUSION KPIs occur frequently and rapidly after LT.Risk factors include female sex,pre-LT diabetes,increased post-LT ALT levels,and urethral catheter duration.CRKP infections,and not KPIs,affect mortality.

Countermeasures to reduce the risk of infections at the 2024 Olympic and Paralympic Games—A balancing act

The Olympic and Paralympic Games are a global celebration of athletic dedication and achievement,bringing together athletes and spectators from around the world.However,such large gatherings present public health challenges for the Organizing Committees and local governments.As highlighted by the coronavirus disease 2019(COVID-19)pandemic,these events are associated with an increased risk of transmission of infections,which can significantly impact the health and well-being of athletes and attendees.Prioritizing the health and safety of athletes,officials and spectators is fundamental to ensure the successful hosting of the Games.Therefore,it is essential to design and implement comprehensive countermeasures to mitigate the risk of an infectious disease outbreak among participants but also to the residents of the host city.

Reinfection and Risk Factors of SARS-CoV-2 during an Omicron Wave 2022 in Shanghai

Multiple waves of coronavirus disease 2019(COVID-19) outbreaks have affected numerous countries worldwide. The first case of SARS-CoV-2 reinfection was reported in Hong Kong in August 2020^([1]), leading to increased interest in the effectiveness of natural immunity acquired from primary infection. While data reports vary across countries, all findings indicate that prior SARS-CoV-2 infection provides substantial protection against reinfection^([2]). However, natural immunity from infection with previous non-Omicron or early Omicron sub-lineages offers lower levels of protection against Omicron reinfection, with rates below 60%^([3]) and approximately 75%[4], respectively.

Prospects and challenges for the application of tissue engineering technologies in the treatment of bone infections

Osteomyelitis is a devastating disease caused by microbial infection in deep bone tissue.Its high recurrence rate and impaired restoration of bone deficiencies are major challenges in treatment.Microbes have evolved numerous mechanisms to effectively evade host intrinsic and adaptive immune attacks to persistently localize in the host,such as drug-resistant bacteria,biofilms,persister cells,intracellular bacteria,and small colony variants(SCVs).Moreover,microbial-mediated dysregulation of the bone immune microenvironment impedes the bone regeneration process,leading to impaired bone defect repair.Despite advances in surgical strategies and drug applications for the treatment of bone infections within the last decade,challenges remain in clinical management.The development and application of tissue engineering materials have provided new strategies for the treatment of bone infections,but a comprehensive review of their research progress is lacking.This review discusses the critical pathogenic mechanisms of microbes in the skeletal system and their immunomodulatory effects on bone regeneration,and highlights the prospects and challenges for the application of tissue engineering technologies in the treatment of bone infections.It will inform the development and translation of antimicrobial and bone repair tissue engineering materials for the management of bone infections.

Caspase-11 mediated inflammasome activation in macrophages by systemic infection of A.actinomycetemcomitans exacerbates arthritis

Clinical studies have shown that Aggregatibacter actinomycetemcomitans(A.actinomycetemcomitans)is associated with aggressive periodontitis and can potentially trigger or exacerbate rheumatoid arthritis(RA).However,the mechanism is poorly understood.Here,we show that systemic infection with A.actinomycetemcomitans triggers the progression of arthritis in mice anti-collagen antibody-induced arthritis(CAIA)model following IL-1βsecretion and cell infiltration in paws in a manner that is dependent on caspase-11-mediated inflammasome activation in macrophages.The administration of polymyxin B(PMB),chloroquine,and anti-CD11b antibody suppressed inflammasome activation in macrophages and arthritis in mice,suggesting that the recognition of lipopolysaccharide(LPS)in the cytosol after bacterial degradation by lysosomes and invasion via CD11b are needed to trigger arthritis following inflammasome activation in macrophages.These data reveal that the inhibition of caspase-11-mediated inflammasome activation potentiates aggravation of RA induced by infection with A.actinomycetemcomitans.This work highlights how RA can be progressed by inflammasome activation as a result of periodontitis-associated bacterial infection and discusses the mechanism of inflammasome activation in response to infection with A.actinomycetemcomitans.

Timing of hepatectomy following the Omicron variant infection for vaccinated-patients:A retrospective cohort study

Many previous studies suggested that severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infection elevated the risk of morbidity and 90-day mortality after operation, especially pulmonary complications [1–7]. Uncertainty about perioperative safety puts off the progress of elective surgery [8]. The Omicron variant has recently become the dominant variant causing prevalence in several countries [9]. Although a high rate of patients with Omicron presented asymptomatic status [10], it is still unclear whether Omicron infection would raise the risk of postoperative complications.

A case of Rickettsia felis infection-induced encephalitis in a pregnant woman

Rickettsia felis is an exclusively cytozoic Gram-negative prokaryote with cat fleas as the major vectors.[1]As early as 1918,Rickettsia felis was detected in cat fleas in Europe and named Rickettsia ctenocephali.[2]Symptoms of fever,malaise,headache,maculopapular rash and eschar are observed in patients with Rickettsia felis infection.