Growth of RB Population in the Conversion Phase of Chlamydia Life Cycle

Upon infecting a host cell,the reticulate body(RB)form of the Chlamydia bacteria simply proliferates by binary fission for an extended period.Available data show only RB units in the infected cells 20 hours post infection(hpi),spanning nearly half way through the development cycle.With data collected every 4 hpi,conversion to the elementary body(EB)form begins abruptly at a rapid rate sometime around 24 hpi.By modeling proliferation and conversion as simple birth and death processes,it has been shown that the optimal strategy for maximizing the total(mean)EB population at host cell lysis time is a bang-bang control qualitatively replicating the observed conversion activities.However,the simple birth and death model for the RB proliferation and conversion to EB deviates in a significant way from the available data on the evolution of the RB population after the onset of RB-to-EB conversion.By working with a more refined model that takes into account a small size threshold eligibility requirement for conversion noted in the available data,we succeed in removing the deficiency of the previous models on the evolution of the RB population without affecting the optimal bang-bang conversion strategy.

Comparative Study of PCR Kits with Cell Culture and LCR in the Detection of Chlamydia Trachomatis Infections

Objective: To determine the diagnostic performancesof six Chinese PCR kits for detection of Chlamydiatrachomatis in patients with sexually transmitteddiseases using cell culture and LCR as references.Methods: Endocervical or urethral swab specimenswere collected from 673 patients attending STDclinics in Beijing, Shanghai, Nanjing and Tianjin. C.trachomatis culture and PCR were performed onspecimens from all patients while LCR detection wasperformed only on specimens with discordant cultureand PCR results.Results: Of the 616 patients, 6.3% (39) wereculture-positive while 23.5% to 28.7% were positiveby PCR testing. Compared to cell culture, the sensi-tivity of all six PCR methods was 90% or higher. In200 cases with discrepant reports, LCR and PCRshowed excellent consistency (YI index: 0.523-0.881 ), the sensitivity and specificity of PCR methodswere 83.9%- 98.6% and 66.7%- 94.7% respectively,while PCR2 showed the highest YI index (0.881). Withthe reference standard defined as culture positive orLCR positive plus at least one PCR positive fordiscrepant results, we found that the specificity andsensitivity of all six Chinese PCR kits were higherthan 95% and 85%, respectively.Conclusions: Domestically-produced PCR kits forChlamydia trachomatis detection are highly sensi-tive and specific, however, quality control remainsimportant in their clinical application.

Prokaryotic Expression and Identification of Outer Membrane Protein 2 of Chlamydia trachomatis

Objective: To construct a recombinant plasmid containing the outer membrane protein 2 (Omp2) gene of Chlamydia trachomatis and express Omp2 in E.coli. Methods: The omp2 gene of C. trachomatis serovar D was cloned into pQE30 vector following PCR amplification from genomic DNA. E. coli M15 transformants were induced to express the fusion protein by IPTG and the product was identified by SDS-PAGE and Western blot. Results: Confirmed by enzyme cleavage analysis and DNA sequencing, a correct recombinant plasmid pQE30/omp2 was constructed. The fusion protein from the transformants was approximately 60 kDa in size in SDS-PAGE analysis, which could specially react with anti-6 X His mouse monoclonal IgG antibodies. Conclusion: We successfully expressed Omp2 in E. coli M15, providing an efficient and simple system for assaying the immunological properties of Omp2.

Study on Drug Resistance and Relative Mechanisms of Chlamydia Trachomatis

Chlamydia Trachomatis (C.T.) is one of the most common pathogens of human sexually transmitted diseases. Treatment of C.T. infection primarily depends on Tetracyclines, Macrolides and Quinolones, but with the wide use of antibiotics an increasing number of drug-resistant Chlamydia trachomatis cases have been reported. This review summarizes the resistant conditions and the possible resistance mechanisms of C.T..

Treatment for Persistent Chlamydial Infection in the Urogenital Tract-a Review Study

Objective： To investigate treatment efficacy for persistent chlamydial infection in the urogenital tract. Methods： 207 patients with persistent chlamydial urogenital infection were treated with tetracycline,azithromycin, ofloxacin or a combination of these.Result： 47.92%-68.60% of patients with persistent chlamydial urogenital infection were cured depending on the drug used. Ofloxacin had better results than tetracycline and azithromycin.Conclusion： Many patients were resistant to treatment with tetracycline and azithromycin. Ofloxacin proved effective.

Bacterial vaginosis:a synthesis of the literature on etiology,prevalence,risk factors,and relationship with chlamydia and gonorrhea infections

Bacterial vaginosis(BV) is a common vaginal disorder in women of reproductive age. Since the initial work of Leopoldo in 1953 and Gardner and Dukes in 1955, researchers have not been able to identify the causative etiologic agent of BV. There is increasing evidence, however, that BV occurs when Lactobacillus spp., the predominant species in healthy vaginal flora, are replaced by anaerobic bacteria, such as Gardenella vaginalis, Mobiluncus curtisii, M. mulieris, other anaerobic bacteria and/or Mycoplasma hominis. Worldwide, it estimated that 20%–30% of women of reproductive age attending sexually transmitted infection(STI) clinics suffer from BV, and that its prevalence can be as high as 50%–60% in high-risk populations(e.g., those who practice commercial sex work(CSW). Epidemiological data show that women are more likely to report BV if they: 1) have had a higher number of lifetime sexual partners; 2) are unmarried; 3) have engaged in their first intercourse at a younger age; 4) have engaged in CSW, and 5) practice regular douching. In the past decade, several studies have provided evidence on the contribution of sexual activity to BV. However, it is difficult to state that BV is a STI without being able to identify the etiologic agent. BV has also emerged as a public health problem due to its association with other STIs, including: human immunodeficiency virus(HIV), herpes simplex virus type 2(HSV-2), Chlamydia trachomatis(CT) and Neisseria gonorrhoeae(NG). The most recent evidence on the association between BV and CT/NG infection comes from two secondary analyses of cohort data conducted among women attending STI clinics. Based on these studies, women with BV had a 1.8 and 1.9-fold increased risk for NG and CT infection, respectively. Taken together, BV is likely a risk factor or at least an important contributor to subsequent NG or CT infection in high-risk women. Additional research is required to determine whether this association is also present in other low-risk sexually active populations, such as among women in the US military. It is essential to conduct large scale cross-sectional or population-based case-control studies to investigate the role of BV as a risk factor for CT/NG infections. These studies could lead to the development of interventions aimed at reducing the burden associated with bacterial STIs worldwide.

Atherosclerosis,inflammation and Chlamydia pneumoniae

Coronary heart disease is the single most common cause of illness and death in the developed world.Coronary atherosclerosis is by far the most frequent cause of ischemic heart disease,and plaque disruption with superimposed thrombosis is the main cause of the acute coronary syndromes of unstable angina,myocardial infarction,and sudden death.Atherosclerosis is the result of a complex interaction between blood elements,disturbed flow,and vessel wall abnormality,involving several pathological processes:inflammation,with increased endothelial permeability,endothelial activation,and monocyte recruitment;growth,with smooth muscle cell proliferation,migration,and matrix synthesis;degeneration,with lipid accumulation;necrosis,possibly related to the cytotoxic effect of oxidized lipid;calcification/ossification,which may represent an active rather than a dystrophic process;and thrombosis,with platelet recruitment and fibrin formation.In this review we discuss these processes and the possible pathological effects of Chlamydia infection and the ensuing phlogosis.

Chlamydia trachomatis and sperm lipid peroxidation in infertile men

<abstract>Aim: To relate the presence of anti-Chlamydial trachomatis IgA in semen with sperm lipid membrane peroxidation and changes in seminal parameters. Methods: Semen samples of the male partners of 52 couples assessed for undiagnosed infertility were examined for the presence of IgA antibody against C. trachomatis. The level of sperm membrane lipid peroxidation was estimated by determining the malondialdehyde (MDA) formation. Results: Sperm membrane of infertile males with positive IgA antibodies against C. trachomatis showed a higher level of lipid peroxidation than that of infertile males with negative IgA antibody (P<0.05). There was a positive correlation (P< 0.01) between the level of C. trachomatis antibody and the magnitude of sperm membrane lipid peroxidation. All the other tested semen parameters were found to be similar in the two groups. Conclusion: The activation of immune system by C. trachomatis may promote lipid peroxidation of the sperm membrane. This could be the way by which C. trachomatis affects fertility.

Development of a Novel PmpD-N ELISA for Chlamydia psittaci Infection

Objective Chlamydia psittaci is an avian respiratory pathogen and zoonotic agent. The wide prevalence of C. psittaci poses a threat to the poultry industry and its employees. However, few commercial kits are available for detecting avian antibodies excluding the in-house ELISA kit. In this study, we developed a novel ELISA kit for detecting antibodies against C. psittaci based on the N-terminal fragment of polymorphic outer membrane protein D （PmpD-N） as the coating antigen. Methods The antigen concentrations, primary antibody, and cut-off value were determined and optimized. The ELISA, designated PmpD-N ELISA, was assessed for sensitivity, specificity, and concordance using sera samples from 48 experimentally infected and 168 uninfected SPF chickens. Results The sensitivity and specificity of PmpD-N ELISA were 97.9%, 100%, respectively, while the concordance was 98.1% as compared to that of MOMP-ELISA. No cross-reaction with positive sera for other avian pathogens was found. Using PmpD-N ELISA, 799/836 clinical samples were positive, including 93.0% and 98.1% positivity in layers and broilers, respectively. Conclusion These data indicate that indirect ELISA with PmpD-N as the antigen candidate is a promising approach for the surveillance of C. psittaci infection.

Evaluation of patients with dry eye disease for conjunctival Chlamydia trachomatis and Ureaplasma urealyticum

AIM：To determine the possibility of the development of dry eye disease（DED） as a result of persistent infection with Chlamydia trachomatis and Ureaplasma urealyticum in the conjunctiva of patients.METHODS： This study was conducted on 58 patients of age range 20-50 y,diagnosed with DED confirmed by Schirmer I test and tear breakup time.The non-dry eye control group included 27 subjects of the same age.Ocular specimens were collected as conjunctival scrapings and swabs divided into three groups： the first used for bacterial culture,the second and third taken to detect Chlamydia trachomatis and Ureaplasma urealyticum by direct fluorescent antibody（DFA） assay and polymerase chain reaction（PCR） method. RESULTS： Chlamydia trachomatis was detected in 65.5% and 76% of DED patients by DFA and PCR methods respectively.Ureaplasma urealyticum was found in 44.8% of DED infected patients using the PCR method.Both organisms were identified in only 37.9% of DED patients found to be infected.Control subjects had a 22%detection rate of Chlamydia trachomatis by DFA assay versus a 7% detection rate by PCR; while Ureaplasma urealyticum was detected in 3.7% of the controls by PCR method.The conjunctival culture revealed that gram positive microorganisms represented 75% of isolates with coagulase negative Staphylococci the most common（50%） followed by Staphylococcus aureus（20%）,whereas gram negative microorganisms occurred in 25% of cases,isolating Moraxella spp.as the most frequent organism. CONCLUSION： Our results tend to point out that Chlamydia trachomatis and Ureaplasma urealyticum were detected in a moderate percentage of patients with DED,and could be a fair possibility for its development.PCR is more reliable in detecting Chlamydia trachomatis than DFA technique.The presence of isolated conjunctival bacterial microflora can be of some potential value.

Correlation of Chlamydia pneumonias infection with primary biliary cirrhosis

AIM:To evaluate the association between Chlamydia pneumoniae (Cpn) infection and primary biliary cirrhosis (PBC). METHODS: CpnIq/G and IgM were determined by enzyme-linked immunosorbent assay (ELBA) in 41 well-established PBC patients and two race-matched control groups (post-hepatitis cirrhosis, n = 70; healthy controls, n = 57). RESULTS: The mean level and seroprevalence of Cpn IgG in PBC group and post-hepatitis cirrhosis (PHC) group were significantly higher than those in healthy controls (46.8±43.4 RU/mL, 49.5±45.2 RU/mL vs28.3±32.7 RU/mL; 68.3%, 71.4%, 42.1%, respectively; P<0.05). There was a remarkably elevated seroprevalence of Cpn IgM in patients with PBC (22.0%) compared to the PHC and healthy control (HC) groups. For the PBC patients versus the HCs, the odds ratios (ORs) of the presence of Cpn IgG and IgM were 2.7 (95% CI 0.9-6.1) and 5.1 (95% CI 1.4-18.5), respectively. Though there was no correlation in the level of Cpn IgG with total IgG in sera of patients with PBC (r = -0.857, P = 0.344>0.05), Cpn IgM was related with the abnormally high concentrations of total IgM in PBC group. CONCLUSION: The results of this study do not support the hypothesis that infection with Chlamydia pneumoniae may be a triggering agent or even a causative agent in PBC, but suggest that Chlamydia pneumoniae infection probably contributes to the high level of IgM present in most patients with PBC.

High frequency of latent Chlamydia trachomatis infection in patients with rhegmatogenous retinal detachment

AIM： To determine the frequency of detection of ocular and extraocular Chlamydia trachomatis （CT） infection in non -high myopes with rhegmatogenous retinal detachment （RRD）. METHODS： This was a single-center, nonrandomized, prospective, case-control study. One hundred and four patients were divided into a study group with RRD （n= 63） and a control group with traumatic retinal detachment （n=41）. Samples of subretinal fluid （SFR）, conjunctival, urethral/cervical swabs, and blood were collected. The frequency of detection of CT infection in SRF samples was determined by polymerase chain reaction （PCR）, direct fluorescence assay （DFA） and cell culture, whereas that in conjunctival swabs was determined by PCR and DFA, and those in urethral/cervical swabs and blood were determined by DFA. Yates Chi-square test （with Bonferroni correction） and two-tailed Student＇s t-test were used for statistical analysis. RESULTS： SRF CT infection was detected more frequently in the study group （50.8%-71.4%） than in the control group （9.8%-12.2%） by all the methods used （P〈 0.01）. The frequency of detection of conjunctival CT infection by DFA was higher in the RRD patients compared with the controls （81.0% vs 24.4%, P=0.004）. The PCR detected conjunctival CT infection more often in the study group than in the controls （46.0% vs89.8%, P= 0.007）. The DFA detected CT in blood specimens almost as frequently as in urogenital specimens, for the RRD patients （61.2% vs 63.5%） and the controls （7.3% vs 9.8%）. CONCLUSION： CT infection is detected with high frequency in non-high myopes with RRD.

Study of the prevalence and association of ocular chlamydial conjunctivitis in women with genital infection by Chlamydia trachomatis, Mycoplasma genitalium and Candida albicans attending outpatient clinic

AIMTo determine the association between chlamydial conjunctivitis and genital infection by Chlamydia trachomatis, Mycoplasma genitalium and Candida albicans, in addition to the possible relationship between cultured bacterial pathogens and oculogenital chlamydial infection.METHODSThis study was performed on 100 (50 symptomatic and 50 asymptomatic) women attending the Gynecological and Obstetric outpatient clinic of Alzahra hospital, Alazhar University. Simultaneously a conjunctival swab was taken from these patients. Polymerase chain reaction (PCR) was done on DNA extracted from both vaginal and conjunctival swab samples. Culture for both vaginal and conjunctival swabs was also done.RESULTSCandida albicans was the predominant organism isolated by culture in 20% and 40% of conjunctival and vaginal swabs respectively. By the PCR method, ocular Chlamydia trachomatis was present in 60% of symptomatic women, while genital Chlamydia trachomatis infection was present in 30% of symptomatic women. The results of this method also indicated that 25/50 (50%) vaginal swabs were positive with PCR for Candida albicans versus 15/50 (30%) were PCR positive in conjunctival swab. Mycoplasma genitalium was present in only 10% of vaginal swabs. Concomitant oculogenital PCR positive results for Chlamydia trachomatis and Candida albicans were 30% and 28% respectively.CONCLUSIONOcular Chlamydia trachomatis was associated with genital Chlamydia trachomatis in a high percentage of women followed by Candida albicans. Cultured bacterial organisms do not play a role in enhancement of Chlamydia trachomatis infection.

Clinical metagenomic sequencing for rapid diagnosis of pneumonia and meningitis caused by Chlamydia psittaci

BACKGROUND Chlamydia psittaci(C.psittaci)is a gram-negative intracellular parasitic pathogenic bacterium that can infect avian and mammalian hosts,including humans.The detection of C.psittaci infections typically relies on traditional antigen-based immunoassays or serological testing that often lack sensitivity and/or specificity.Metagenomic next generation sequencing(mNGS)is an emerging tool for diagnosis.AIM To demonstrate that mNGS represents a valuable tool for rapid,sensitive,and accurate pathogen detection including C.psittaci infections.METHODS Four cases of psittacosis pneumonia and one case of pediatric psittacosis meningitis were diagnosed between December 2019 and May 2020 using mNGS at Changzhou Second People’s Hospital affiliated to Nanjing Medical University.Patients’clinical characteristics,manifestations,and treatment histories were retrospectively evaluated.RESULTS All five patients had a history of exposure to wild(psittacine or other birds)or domesticated birds(chickens).All patients had a high fever(>39℃)and three of them(60%)experienced organ insufficiency during the disease.The laboratory data showed normal to slightly increased leucocyte and neutrophil counts,and elevated procalcitonin levels in all five cases,and very high C-reactive protein levels in psittacosis pneumonia patients.mNGS identified a potential pathogen,C.psittaci,in patients’bronchoalveolar lavage fluid or cerebrospinal fluid.Computed tomography revealed lung air-space consolidation,pleural thickening,and effusion fluid buildup in psittacosis pneumonia cases,and an arachnoid cyst in the right temporal lobe of the pediatric psittacosis meningitis patient.All patients experienced complete recovery following the administration of targeted antichlamydia therapy.CONCLUSION This study not only demonstrated that mNGS represents a valuable tool for rapid,sensitive,and accurate pathogen detection,but also raised public health concerns over C.psittaci infections.

Patients with Cervical Ureaplasma Urealyticum and Chlamydia Trachomatis Infection Undergoing IVF/ICSI-ET: The Need for New Paradigm

Genital tract infections with ureaplasma urealyticum（UU） and chlamydia trachomatis（CT） are the most frequent sexually-transmitted disease worldwide. UU and CT infections are considered to be the leading cause for infertility and adverse pregnancy outcomes. However, little is known about the specific effect of cervical UU and CT infections on the etiology of female infertility, as well as the pregnancy outcomes of the patients undergoing in vitro fertilization/intracytoplasmic sperm injection-embryo transfer（IVF/ICSI-ET）. In order to find the association between cervical UU and/or CT infection and pregnancy outcomes, we conducted a retrospective case-control study on the patients undergoing IVF/ICSI-ET with cervical UU and/or CT infection. A total of 2208 patients who received IVF/ICSI-ET were enrolled in this study. Data on the general conditions, pregnancy history and clinical pregnant outcomes were analyzed in terms of the cervical UU and CT detection. Our results revealed that cervical UU and CT infections were the risk factors for ectopic pregnancy and tubal factor-induced infertility. Moreover, the pregnancy rate, abortion rate, ectopic pregnancy rate and premature birth rate in patients with UU and/or CT infections showed no significant difference when compared with the control group. We recommend that cervical UU and CT detection should be an optional item for infertility patients and clinical UU detection should differentiate the subtypes of cervical UU. Positive cervical UU and CT infections should not be taken as strict contraindications for IVF/ICSI-ET.

The Association between <i>Chlamydia Trachomatis</i>and Ectopic Pregnancy in Lagos, Nigeria—A Case Control Study

Objectives: To determine the seropositivity of Chlamydia antibody in patients with ruptured ectopic pregnancy compared to normal pregnant women and the risk factors for ectopic pregnancy. Study Design: This was a prospective case-control study of 85 cases of ruptured ectopic pregnancy and 100 cases of second trimester on-going intrauterine pregnant controls presenting in Lagos State University Teaching Hospital (LASUTH) between September 2009 and March 2010. Study Site: This was at the gynaecological emergency room and antenatal clinic in the Department of Obstetrics and Gynaecology. Ethical approval was sought and granted by the ethics review committee of LASUTH. Study Participants: Patients presenting with ruptured ectopic pregnancy were recruited as cases while the controls were made up of those with uncomplicated second trimester intrauterine pregnancy. A semi-structured questionnaire containing socio-demographic and clinical characteristics was administered following informed consent. Five milliliters of venous blood was taken from each participant and tested for?Lymphogranuloma Venerum?(LGV) type 2 broadly reacting antigen of?Chlamydia trachomatis.?Data Analysis: Data gathered from the case notes and laboratories were imputed into the computer and analyzed using the statistical package?Epi-Info 3.51, Atlanta, USA. Frequency tables were generated for continuous variables and?chi-square analysis used to determine association between variables, with p values <0.05 considered statistically significant. Results: There were 91 cases of ectopic pregnancy among a total of 2468 deliveries giving an incidence of 3.68% or 1 in 27 deliveries. Factors which significantly contributed to increased incidence of ectopic pregnancy in this study were: level of education (p = 0.001), socio-economic status (p = 0.001), parity (p = 0.005), early age of sexual debut (p = 0.001), multiple sexual partners (p = 0.001), previous pelvic inflammatory disease (p = 0.003), previous induced abortion (p = 0.013) and previous?postabortal/puerperal sepsis (p = 0.013). The seropositivity of?Chlamydia IgG (62.4%) in the cases was significantly higher than that of 29% in the control (p < 0.0001). Conclusion: There was a high incidence of ectopic during the period of study and the seropositivity of Chlamydia IgG antibody was significantly higher amongst the cases. Risk factors identified were low level of education, low socio-economic status, low parity, early age of sexual debut, multiple sexual partners, previous history of pelvic inflammatory disease, previous induced abortion and previous postabortal/puerperal sepsis.

Screening for asymptomatic chlamydia and gonorrhea in adolescent males in an urban pediatric emergency department

AIM To determine the prevalence of Chlamydia trachomatis(CT) and Neisseria gonorrhea(GC) in young men seeking care in the emergency department(ED) for non-sexually transmitted infection(STI) related symptoms.METHODS This was a prospective, cross-sectional study in an urban ED. The main outcome was the rate of positive CT and GC on urine nucleic acid amplification testing in males aged 16-21 presenting with non-STI related complaints. RESULTS Two hundred and eighty-four patients were enrolled, 271 were included in the final data analysis [age range 16-21, median: 18(quartiles 16-18, 19-21)]. Overall, 17(6.3%, 95%CI: 4%-10%) tested positive for CT and 0%(95%CI: 0%-2%) were found to have GC. The proportion of sexually active subjects was 71%(95%CI: 65%-76%) and 2%(95%CI: 0.6%-4%) reported sex with men. Previous STI testing was reported in 46%(95%CI: 43%-54%) and 13%(95%CI: 8%-20%) of those patients previously tested had a history of STI. Of the patients who tested positive for CT in the ED, 88%(95%CI: 64%-98%) were successfully followed up. CONCLUSION The prevalence of CT infection found by screening was 6.3%. Screening and follow-up from the ED was successful. The findings justify routine STI screening in male adolescents presenting to the ED with non-STI related complaints.

Evaluating Potential Vaccine Antigens in both the <i>Chlamydia trachomatis</i>and <i>Chlamydia muridarum</i>Intravaginal Mouse Challenge Models

Identifying relevant animal challenge models adds to the complexity of human vaccine development. Murine challenge models have been the most utilized animal model for Chlamydia trachomatis vaccine development. The question arises as to whether the C. trachomatis or C. muridarum pre-clinical model is optimal. We compared C. muridarum and C. trachomatis intravaginal challenge models in a combined total of seventy-five studies evaluating potential vaccine candidates. In 100% (42/42) of C. muridarum studies, mice immunized with Chlamydia elementary bodies (EB) demonstrated a significant reduction in urogenital bacterial shedding as measured by qPCR (p C. trachomatis studies. We have evaluated proposed vaccine antigens in both models and observed immunization with Chlamydia major outer membrane protein (MOMP) vaccine formulations to be protective (p C. trachomatis model, and immunization with PmpD p82 translocator domain was not protective in either model. We also observed in both models that depletion of CD4+ T-cells in MOMP-immunized mice resulted in diminished protective immunity but animals were still able to reduce the infection level. In contrast, mice immunized with live EBs by intraperitoneal route did not require CD4+ T-cells to resolve urogenital infection from intravaginal challenge in either model. Overall, we have found the C. muridarum model to be a more robust, reliable, and reproducible model for vaccine antigen discovery.

Clustering cases of Chlamydia psittaci pneumonia mimicking COVID-19 pneumonia

BACKGROUND The onset symptoms of people infected by Chlamydia psittaci can mimic the coronavirus disease 2019(COVID-19).However,the differences in laboratory tests and imaging features between psittacosis and COVID-19 remain unknown.AIM To better understand the two diseases and then make an early diagnosis and treatment.METHODS Six patients from two institutions confirmed as psittacosis by high-throughput genetic testing and 31 patients confirmed as COVID-19 were retrospectively included.The epidemiology,clinical characteristics,laboratory tests and computed tomography(CT)imaging features were collected and compared between the two groups.The follow-up CT imaging findings of patients with psittacosis were also investigated.RESULTS The white blood cell count(WBC),neutrophil count and calcium were more likely to be decreased in patients with COVID-19 but were increased in patients with psittacosis(all P=0.000).Lymphocyte count and platelet count were higher in patients with psittacosis than in those with COVID-19(P=0.044,P=0.035,respectively).Lesions in patients with psittacosis were more likely to be unilateral(P=0.001),involve fewer lung lobes(P=0.006)and have pleural effusions(P=0.002).Vascular enlargement was more common in patients with COVID-19(P=0.003).Consolidation in lung CT images was absorbed in all 6 patients.CONCLUSION Psittacosis has the potential for human-to-human transmission.Patients with psittacosis present increased WBC count and neutrophil count and have specific CT imaging findings,including unilateral distribution,less involvement of lung lobes and pleural effusions,which might help us to differentiate it from COVID-19.

Serosurvey of Avian metapneumovirus, Orithobacterium rhinotracheale, and Chlamydia psittaci and Their Potential Association with Avian Airsacculitis

Seasonal outbreaks of airsacculitis in China＇s poultry cause great economic losses annually. This study tried to unveil the potential role of Avian metopneumovirus （AM PV）, Ornithobacterium rhinotrocheale （aRT） and Chlarnydia psittaci （CPS） in avian airsacculitis. A serological investigation of 673 breeder chickens and a case-controlled study of 430 birds were undertaken. Results showed that infection with AMPV, aRT, and CPS was highly associated with the disease. The correlation between AMPV and CPS were positively robust in both layers and broilers. Finally, we determined the co-infection with AMPV, aRT, and CPS was prevalent in the sampled poultry farms suffering from respiratory diseases and the outbreak of airsacculitis was closely related to simultaneous exposure to all three agents.