Nucleic Acid Amplification Assays Research Articles

Toscana virus associated with Guillain–Barré syndrome: a case–control study

Guillain-Barré syndrome (GBS) is an acute-onset, immune-mediated polyradiculoneuropathy, often precipitated by an antecedent infection. An association of GBS with vector-borne viral infections has been suggested, with evidence for the involvement of Zika, Dengue, Chikungunya and West Nile virus (WNV). This prospective case-control study was conducted to identify vector-borne viral infections in GBS. Thirteen individuals newly diagnosed as GBS were enrolled. Disease severity, prognostic factors and nerve conduction patterns were assessed. Eleven individuals with non-infectious conditions requiring cerebrospinal fluid (CSF) analysis were included as controls. Plasma, CSF and urine specimens were evaluated via nucleic acid amplification assays aimed to detect a broad spectrum of viruses. WNV and Toscana virus (TOSV) IgM/IgG antibodies were screened using commercial immunofluorescence assays and confirmed via virus neutralization tests (VNT). Partial TOSV nucleocapsid and genotype 1 polymerase sequences were detected in CSF of a patient with normal pressure hydrocephalus. Two control subjects had VNT-confirmed TOSV IgM in plasma. VNT-confirmed WNV and TOSV IgG were detected in 15.4% and 61.5% of GBS patients, respectively. Variations in WNV IgG and TOSV IgM detection rates were not statistically significant among study cohorts. However, TOSV IgG was significantly more frequent in GBS patients. No difference was observed for disease form or prognostic scores for virus markers. Follow-up serological profiles were identical to the initial findings. We have identified TOSV as a potential precipitating agent in GBS, with some rare clinical presentations of symptomatic TOSV infections.

Fractal LAMP: Label-Free Analysis of Fractal Precipitate for Digital Loop-Mediated Isothermal Nucleic Acid Amplification.

Nucleic acid amplification assays including loop-mediated isothermal amplification (LAMP) are routinely used in diagnosing diseases and monitoring water and food quality. The results of amplification in these assays are commonly measured with an analog fluorescence readout, which requires specialized optical equipment and can lack quantitative precision. Digital analysis of amplification in small fluid compartments based on exceeding a threshold fluorescence level can enhance the quantitative precision of nucleic acid assays (i.e., digital nucleic acid amplification assays), but still requires specialized optical systems for fluorescence readout and the inclusion of a fluorescent dye. Here, we report Fractal LAMP, an automated method to detect amplified DNA in subnanoliter scale droplets following LAMP in a label-free manner. Our computer vision algorithm achieves high accuracy detecting DNA amplification in droplets by identifying LAMP byproducts that form fractal structures observable in brightfield microscopy. The capabilities of Fractal LAMP are further realized by developing a Bayesian model to estimate DNA concentrations for unknown samples and a bootstrapping method to estimate the number of droplets required to achieve target limits of detection. This digital, label-free assay has the potential to lower reagent and reader cost for nucleic acid measurement while maintaining high quantitative accuracy over 3 orders of magnitude of concentration.

Where do we Stand on the Molecular Diagnostics for the Detection of Human Papillomavirus? A Comprehensive Review

Human Papillomavirus (HPV) infection plays a vital role in the development of various cancers and imposes a burden on the global health. Detection of HPV infection is a challenge to the healthcare industry as they cannot be cultured and their fascinating life cycle limits the accuracy of serological methods. Hence, molecular assays are the gold standard for the accurate viral detection and genotyping. Currently, various methodologies are available with great sensitivity and specificity and are even clinically validated as screening tools. However, there are only a few that are approved by the US Food and Drug Administration and much more are suitable only for research. At present, the molecular methods available mainly depend on signal amplification, nucleic acid amplification and hybridisation assays for detecting and genotyping HPV infection, all with their own advantages and drawbacks. There is further scope for the development of more reliable, cost-effective diagnostic techniques that can harness the power of next genome sequencing, mutation analysis and may further improve the chances of early detection and prevention of HPV related cancers. This review summarises the present knowledge on currently available molecular diagnostic tests for the detection and genotyping of HPV infection and their possible utility in a clinical setting.

RAPID AND SPESIFIC DETECTION OF MYCOBACTERIUM TUBERCULOSIS USING POLYMERASE CHAIN REACTION

Background: Tuberculosis (TB) is one of the major causes of health burden worldwide, especially in lower middle-income countries. TB is caused by Mycobacterium tuberculosis (MTB) and characterized by severe condition incuding coughing and fever. Purpose: To review the current methods for detection of TB using Polymerase Chain Reaction (PCR). Review: several studies have been done to give valuable insight into TB transmission, diagnosis, and treatment, however research is constantly needed to decrease the incidence of eradicate TB. This infectious disease still give big health problem in all over the world by being second in causing high mortality rates after HIV/AIDS. A specific, sensitive, rapid and cheap method for TB and other mycobacteria diagnosis in clinical specimen is a desperate needed in the laboratory diagnosis and hence management of tuberculosis. PCR as one of nucleic acid amplification assays have revolutionized MTB detection. Since it was first invented in fifteen years ago, it’s been through many developments. Conclusion: PCR is one of the most specific and sensitive method currently available for TB diagnosis that can also detect in in all types of specimens obtained from TB patients.

Microbiological Diagnosis of Skeletal System Infections in Children.

If not timely diagnosed and adequately treated, skeletal system infections in children may result in severe and permanent disability. Prompt identification of the etiology of the disease and determination of its antibiotic susceptibility are crucial for the successful management of septic arthritis, osteomyelitis, and spondylodiscitis. However, the bacteriological diagnosis of these infections has been traditionally limited by the low yield of conventional cultures and, on average, one-third of cases of pediatric joint and bone infections remained unconfirmed. To review the medical literature to summarize the current approach diagnosing the pediatric skeletal system infections. The relevant publications for the last three decades were reviewed. In recent years, the detection of skeletal system pathogens has been revolutionized by the use of improved laboratory methods, including seeding of synovial fluid and bone exudates into blood culture vials, and the development and implementation of sensitive nucleic acid amplification assays. These advances have resulted in the recognition of Kingella kingae as the predominant etiology of hematogenous infections of bones, joints, intervertebral discs and tendon sheaths in children aged 6-48 months, and reduced the fraction of culture-negative osteoarthritis. As the exudate and tissue samples obtained from young children with skeletal system infections are frequently insufficient for a comprehensive laboratory workup, physicians should take in consideration the patient's age, predisposing medical conditions and possible exposure to zoonotic organisms, and use a judicious combination of Gram's stain, culture on blood culture vials, and molecular tests to maximize the microbiological diagnosis of these diseases.

Challenges in diagnosing scrub typhus among hospitalized patients with undifferentiated fever at a national tertiary hospital in northern Vietnam.

BackgroundScrub typhus (ST) is a leading cause of non-malarial febrile illness in Southeast Asia, but evidence of its true disease burden is limited because of difficulties of making the clinical diagnosis and lack of adequate diagnostic tests. To describe the epidemiology and clinical characteristics of ST, we conducted an observational study using multiple diagnostic assays at a national tertiary hospital in Hanoi, Vietnam.Methodology/Principal findingsWe enrolled 1,127 patients hospitalized with documented fever between June 2012 and May 2013. Overall, 33 (2.9%) patients were diagnosed with ST by PCR and/or screening of ELISA for immunoglobulin M (IgM) with confirmatory tests: 14 (42.4%) were confirmed by indirect immunoperoxidase assay (IIP), and 19 (57.6%) were by IIP and PCR. Living by farming, conjunctival injection, eschar, aspartate aminotransferase elevation, and alanine aminotransferase elevation were significantly associated with ST cases (adjusted odds ratios (aORs): 2.8, 3.07, 48.8, 3.51, and 4.13, respectively), and having a comorbidity and neutrophilia were significantly less common in ST cases (aORs: 0.29 and 0.27, respectively). The majority of the ST cases were not clinically diagnosed with rickettsiosis (72.7%). Dominant IIP reactions against a single antigen were identified in 15 ST cases, whereas indistinguishably high reactions against multiple antigens were seen in 11 ST cases. The most frequently observed dominant IIP reaction was against Karp antigen (eight cases) followed by Gilliam (four cases). The highest diagnostic accuracy of IgM ELISA in acute samples was 78%. In a phylogenetic analysis of the 56-kDa type-specific antigen gene, the majority (14 cases) were located in the Karp-related branch followed by the Gilliam-related (two cases), Kato-related (two cases), and TA763-related clades (one case).Conclusions/SignificanceBoth the clinical and laboratory diagnoses of ST remain challenging at a tertiary hospital. Implementation of both serological and nucleic acid amplification assays covering endemic O. tsutsugamushi strains is essential.

Kingella kingae and Osteoarticular Infections.

In this study, we aimed to contrast the bacteriologic epidemiology of osteoarticular infections (OAIs) between 2 patient groups in successive 10-year periods, before and after the extensive use of nucleic acid amplification assays in the diagnostic process. Epidemiologic data and bacteriologic etiologies of all children presenting with OAIs on admission to our institution over 20 years (1997-2016) were assessed retrospectively. The population was divided into 2 cohorts, using the standardized use of polymerase chain reaction as the cutoff point (2007). The conventional cohort included children with OAIs mainly investigated by using classic cultures, whereas the molecular cohort referred to patients also investigated by using molecular assays. Kingella kingae was the most frequently isolated pathogen, responsible for 51% of OAIs, whereas other classic pathogens were responsible for 39.7% of cases in the molecular cohort. A statistically significant increase in the mean incidence of OAIs was observed, as was a decrease in the mean age at diagnosis after 2007. After 2007, the pathogen remained unidentified in 21.6% of OAIs in our pediatric population. Extensive use of nucleic acid amplification assays improved the detection of fastidious pathogens and has increased the observed incidence of OAI, especially in children aged between 6 and 48 months. We propose the incorporation of polymerase chain reaction assays into modern diagnostic algorithms for OAIs to better identify the bacteriologic etiology of OAIs.

Laboratory Diagnosis of Human Brucellosis.

The clinical presentation of brucellosis in humans is variable and unspecific, and thus, laboratory corroboration of the diagnosis is essential for the patient's proper treatment. The diagnosis of brucellar infections can be made by culture, serological tests, and nucleic acid amplification assays. Modern automated blood culture systems enable detection of acute cases of brucellosis within the routine 5- to 7-day incubation protocol employed in clinical microbiology laboratories, although a longer incubation and performance of blind subcultures may be needed for protracted cases. Serological tests, though they lack specificity and provide results that may be difficult to interpret in individuals repeatedly exposed to Brucella organisms, nevertheless remain a diagnostic cornerstone in resource-poor countries. Nucleic acid amplification assays combine exquisite sensitivity, specificity, and safety and enable rapid diagnosis of the disease. However, long-term persistence of positive molecular test results in patients that have apparently fully recovered is common and has unclear clinical significance and therapeutic implications. Therefore, as long as there are no sufficiently validated commercial tests or studies that demonstrate an adequate interlaboratory reproducibility of the different homemade PCR assays, cultures and serological methods will remain the primary tools for the diagnosis and posttherapeutic follow-up of human brucellosis.

2799. Inability to Locally Differentiate Rhinovirus/Enterovirus Results Impacts Infection Control Practices

BackgroundRhinoviruses and Enteroviruses are closely related members of the family picornavirideae; however, they have distinct clinical manifestations. Rhinoviruses cause respiratory infections while Enteroviruses often present as nonspecific febrile illnesses. Enterovirus D68 (EV-D68) is unusual in that although it is classified as an enterovirus it causes respiratory illness. Most of the currently used nucleic acid amplification assays for respiratory viruses do not distinguish between Rhino and Enteroviruses because of their shared homology. Rhino/Enterovirus infections are common in the Summer and Fall. In October of 2018 the NYS DOH issued a health advisory describing increased numbers of EV-D68 infection. Although there is no specific treatment for EV-D68, the advisory recommended contact precautions in addition to the droplet precautions recommended for other respiratory viruses. This recommendation creates logistical difficulties since there are no commercial test-kits that can identify EV-D68. The aim of this study was to determine the incidence of EV-D68 among patients admitted to Stony Brook Hospital that tested positive for Rhino/Enterovirus.MethodsNasopharyngeal swabs were tested with the BioFire® FilmArray® Respiratory Panel (RP 2) test. 44 Rhino/Enterovirus positive specimens were sent for further identification to the NYS DOH Virology Lab. Enterovirus was differentiated from Rhinovirus by qRT–PCR. EV-D68 was identified by sequencing.ResultsDuring one week in October, 10 patients were admitted with positive EV-D68 (5 adults and 5 children). In contrast, all 21 admitted patients who had specimens sent for typing had Rhinovirus.ConclusionThis study confirmed that there was significant EV-D68 activity among patients who required hospitalization consistent with the NYS DOH advisory in the Fall of 2018. In contrast, in the Winter a drop in the prevalence of Rhino/enterovirus was observed. EV-D68 was not found in any of the samples sent for typing. These data informed our internal decision to cohort all patients this past Winter with positive Rhino/enterovirus results, positively impacting patient cohorting capabilities during a time with increased local influenza activity. Disclosures All authors: No reported disclosures.

‘Ready Mixed’, improved nucleic acid amplification assays for the detection of Escherichia coli DNA and RNA

The selective amplification of E. coli nucleic acid sequences could be used for the early warning of faecal contamination in environmental samples. Modified assays for E. coli DNA and RNA markers are presented with improved integrity and performance over existing methods, and demonstrated using ‘ready mixed’, preserved reagent mixtures.

Comparative analysis of Four sample-to-answer influenza A/B and RSV nucleic acid amplification assays using adult respiratory specimens

BackgroundThe use of Sample-to-answer (STA) platforms for the detection of influenza A/B and respiratory syncytial virus (RSV) have greatly improved patient care. These diagnostic assays based on nucleic acid amplification are rapid, accurate and relatively easy to perform. ObjectivesWe compared four such platforms for detecting FluA, FluB, and RSV from adult respiratory specimens: Hologic Panther Fusion® Flu A/B/RSV (Fusion), Cobas® Influenza A/B & RSV (Liat), Luminex Aries® Flu A/B & RSV (Aries), and Diasorin SimplexaTM Flu A/B & RSV (Simplexa). Study DesignNasopharyngeal (NP) swabs (n = 224) from adults were tested on these platforms and results were compared to Center for Disease Control and Prevention recommended real-time RT-PCR assay for influenza A/B and RSV. Subtyping for FluA and FluB was performed for discrepant analysis where applicable. ResultsOf the 82 FluA, 26 FluB, 15 RSV-positive specimens tested, the positive and negative percentage agreements (PPA and NPA respectively) for FluA detection were 100/100 (Fusion), 95.1/100 (Liat), 92.5/100 (Aries), and 84.1/99.3 (Simplexa); PPA and NPA for FluB detection were 92.3/99.5 (Fusion), 96/99.5 (Liat), 100/99.5 (Aries), and 80.8/100 (Simplexa); and for RSV detection were 100/100 (Fusion), 100/100 (Liat), 88.6/99.5 (Aries), and 73.3/100 (Simplexa). 82 confirmed FluA included 23 pH1N1 and 57 H3N2 strains with 2 strains remaining untyped. Of the 26 confirmed FluB, 25 were of the Yamagata lineage and 1 of unknown lineage. ConclusionOnly 2 STA platforms demonstrated >95% PPA for the detection of all three targets while all the 4 platforms demonstrated >95% NPA for FluA, FluB and RSV.

Quantitative COBAS AmpliPrep/ COBAS TaqMan test shows good performance for HIV screening among blood donors in Maputo, Mozambique

Quantitative <scp>COBAS</scp> AmpliPrep/ <scp>COBAS</scp> TaqMan test shows good performance for <scp>HIV</scp> screening among blood donors in Maputo, Mozambique

Arboviral screening of invasive Aedes species in northeastern Turkey: West Nile virus circulation and detection of insect-only viruses.

BackgroundThe recent reports of Aedes aegypti and Ae. albopictus populations in Turkey, in parallel with the territorial expansion identified in several surrounding countries, have raised concerns about the establishment and re-establishment of these invasive Aedes mosquitoes in Turkey. This cross-sectional study was performed to detect Aedes aegypti and Ae. albopictus in regions of recent incursions, and screen for viral pathogens known to be transmitted elsewhere by these species.MethodologyMosquitoes were collected at several locations in Artvin, Rize and Trabzon provinces of the Black Sea region during 2016–2017, identified morphologically, pooled and analyzed via generic or specific nucleic acid amplification assays. Viruses in positive pools were identified by product sequencing, cell culture inoculation and next generation sequencing (NGS) in selected specimens.Principal findingsThe study group comprised 791 specimens. Aedes albopictus was the most abundant species in all locations (89.6%), followed by Ae. aegypti (7.8%) and Culex pipiens (2.5%). Mosquitoes were screened for viruses in 65 pools where fifteen (23.1%) were reactive. The infecting strains was identified as West Nile virus (WNV) in 5 pools (7.7%) with Ae. albopictus or Cx. pipiens mosquitoes. The obtained WNV sequences phylogenetically grouped with local and global lineage 1 clade 1a viruses. In 4 (6.2%) and 6 (9.2%) pools, respectively, cell fusing agent virus (CFAV) and Aedes flavivirus (AEFV) sequences were characterized. NGS provided a near-complete AEFV genome in a pool of Ae. albopictus. The strain is provisionally called “AEFV-Turkey”, and functional analysis of the genome revealed several conserved motifs and regions associated with virus replication. Merida-like virus Turkey (MERDLVT), a recently-described novel rhabdovirus, was also co-detected in a Cx. pipiens pool also positive for WNV.Conclusions/SignificanceInvasive Aedes mosquitoes are established in certain locations of northeastern Turkey. Herein we conclusively show the role of these species in WNV circulation in the region. Biosurveillance is imperative to monitor the spread of these species further into Asia Minor and to detect possible introduction of pathogens.

Emerging Analytical Techniques for Rapid Pathogen Identification and Susceptibility Testing.

In the face of looming threats from multi-drug resistant microorganisms, there is a growing need for technologies that will enable rapid identification and drug susceptibility profiling of these pathogens in health care settings. In particular, recent progress in microfluidics and nucleic acid amplification is pushing the boundaries of timescale for diagnosing bacterial infections. With a diverse range of techniques and parallel developments in the field of analytical chemistry, an integrative perspective is needed to understand the significance of these developments. This review examines the scope of new developments in assay technologies grouped by key enabling domains of research. First, we examine recent development in nucleic acid amplification assays for rapid identification and drug susceptibility testing in bacterial infections. Next, we examine advances in microfluidics that facilitate acceleration of diagnostic assays via integration and scale. Lastly, recentdevelopments in biosensor technologies are reviewed. We conclude this review with perspectives on the use of emerging concepts to develop paradigm-changing assays.

748. The Impact of a Positive Respiratory Viral Panel Among Hospitalized Adult Patients with Negative Rapid Influenza Testing at an Academic Tertiary Care Facility: A-matched Cohort Study

BackgroundMultiplex nucleic acid amplification assays (NAATs) are increasingly used to evaluate respiratory illnesses. Viral diagnosis has the potential to change clinical management and, specifically, decrease antibiotic use. However, the assays are expensive, and their effect on clinical management is unknown. This study evaluated the incremental impact of a multiplex respiratory viral panel after negative rapid influenza testing.MethodsWe completed a retrospective review of all adult patients with respiratory viral panel (RVP; GenMark) and/or rapid influenza or RSV/influenza PCR tests (PCR; Cepheid Xpert) collected within 48 hours of admission to non-ICU, inpatient units from September 1, 2015 to April 15, 2016. We matched hospitalizations with a positive RVP simultaneously with or following negative PCR testing (PCR−RVP+) 1:1 with patient encounters with negative rapid PCR testing only (PCR−). Matching of the referent PCR-group occurred without replacement based on age (±10 years), sex, race, season of testing (±50 days), and any respiratory viral test in the prior 30 days. The primary outcome was a change in management, defined as antimicrobial de-escalation (discontinuation, switch from intravenous to oral administration, and/or narrowing of spectrum), antiviral initiation, and/or change in isolation precautions.ResultsDuring the study period, there were 153 PCR−RVP+ patient encounters and 524 with PCR− testing only from which we identified 134 matched pairs. In the matched cohort, the median age was 60 years (IQR: 41–71), 47.8% were female, and 34.3% were non-White. Respiratory viral testing was associated with management change in 3.7% of PCR− and 23.9% of PCR−RVP+ patients (risk difference 20.1%; 95% CI 12.2–28.0%). Antimicrobial de-escalation did not occur after testing for any PCR- patients but did occur for 15.7% of PCR−RVP+ patients (95% CI 9.5–21.8%).ConclusionAmong patients with negative rapid influenza testing, a subsequent or simultaneous positive RVP was associated with a higher frequency of antibiotic de-escalation. This suggests multiplex NAATs could play a role in improving antimicrobial stewardship in the setting of respiratory illness.Disclosures M. Miller, GenMark: Investigator, Research support. R. Jhaveri, GenMark: Investigator, Research support.

Portable fluorescence-based microRNA detection system based on isothermal signal amplification technology.

MicroRNAs (miRNAs) diagnostics can be useful for diagnosing or confirming miRNA abundance and are used in screening tests and to assess changes in miRNAs in vivo. At present, the use of traditional nucleic acid amplification assays to detect miRNAs has been limited in laboratory environment because of the time, equipment, and technical expertise required to perform these assays. A specialized, rapid affordable miRNA detection system is necessary when there are limited resources or point-of-care testing needs. We designed a portable and affordable fluorescence-based miRNA detection system based on isothermal signal amplification technology, using SYBR Green II as a fluorescent dye. To reduce costs, we chose LED as a light source and designed the corresponding optical path for LED. The portable detection system shows results consistent with those by real-time PCR, and can be used to detect miR-183 with a limit of detection of approximately 2fmol. We used the system to detect miR-183 in tissues and blood from patients with hepatocellular carcinoma (HCC). The results from the portable detection device were compared with those from clinical trials and indicated that the miR-183 fluorescence signal could successfully identify HCC and provide information related to cancer progression.

An Affordable and Portable Thermocycler for Real-Time PCR Made of 3D-Printed Parts and Off-the-Shelf Electronics.

The polymerase chain reaction (PCR) is a sought-after nucleic acid amplification technique used in the detection of several diseases. However, one of the main limitations of this and other nucleic acid amplification assays is the complexity, size, maintenance, and cost of their operational instrumentation. This limits the use of PCR applications in settings that cannot afford the instruments but that may have access to basic electrical, electronic, and optical components and the expertise to build them. To provide a more accessible platform, we developed a low-cost, palm-size, and portable instrument to perform real-time PCR (qPCR). The thermocycler leverages a copper-sheathed power resistor and a computer fan, in tandem with basic electronic components controlled from a single-board computer. The instrument incorporates a 3D-printed chassis and a custom-made fluorescence optical setup based on a CMOS camera and a blue LED. Results are displayed in real-time on a tablet. We also fabricated simple acrylic microdevices consisting of four wells (2 μL in volume each) where PCR reactions take place. To test our instrument, we performed qPCR on a series of cDNA dilutions spanning 4 orders of magnitude, achieving similar limits of detection as those achieved by a benchtop thermocycler. We envision our instrument being utilized to enable routine monitoring and diagnosis of certain diseases in low-resource areas.

Paradigm for diagnosing mycobacterial disease: direct detection and differentiation of Mycobacterium tuberculosis complex and non-tuberculous mycobacteria in clinical specimens using multiplex real-time PCR

AimsMycobacterium tuberculosis and non-tuberculous mycobacteria (NTM) are clinically different, and the rapid detection and differentiation of M. tuberculosis complex (MTBC) and NTM is crucial for patient management and infection control....

Comparison of Different Methods of RNA Preparation from Peripheral Blood for Nucleic Acid Amplification Assay

Background: Nucleic acid amplification assays (NAAs), such as polymerase chain reaction or loop-mediated isothermal amplification (LAMP), are used for disease diagnosis. Current nucleic acid isolation kits require several hours for completion of protocol including the complicated handling steps. Objective: In this study, a simple and cost-effective nucleic acid preparation method was developed, and its performance was compared with those of commercial kits. Materials and Methods: RNA was prepared using our method and three commercial RNA isolation kits. The RNA quantity and quality were evaluated using the NanoDrop spectrophotometer and Agilent 2100 bioanalyser. Reverse transcription LAMP (RT-LAMP) reactions were performed to determine the usability of the RNA preparation methods. Results: The concentrations of RNA extracted from blood samples by four different methods were sufficient for use in NAAs. The RNA integrity number was >7.0 when RNA was isolated using other RNA isolation kits but lower when prepared using our method. The RT-LAMP reaction was successfully performed when RNA was prepared using any of the methods. Conclusions: These results demonstrate that despite the lower purity and integrity of RNA, our RNA preparation protocol is simple and rapid and shows reasonable performance in RT-LAMP.

Trichomonas Vaginalis: controversy questions

Trichomoniasis is the most common non-viral infection in the sexually transmitted world and is caused by Trichomonas vaginalis, a single-celled parasite that belongs to the flagellate class. Trichomoniasis is not subject to reporting in many countries, and therefore, assessing the prevalence of infection in population screening is complicated.According to the WHO, in 2008 there were 276.4 million cases, the global prevalence of Tr. vaginalis was 8.1% for women and 1.0% for men. The level of Tr. vaginalis differs greatly from the population, the country, the methods of identification of the pathogen. One of the important reasons for diagnosis and treatment of T. vaginalis is the increased risk of infection and transmission of HIV from 2.1 to 2.8 times when it is available.Most women (85%) and men (77%) with Tr. vaginalis have no clinical symptoms. In one third of infected women, symptoms appear within 6 months. Among those who have clinical manifestations, they are nonspecific: the presence of vaginal discharge of varying intensity and density, dysuria, itching, irritation, aching pain in the lower abdomen. The available diagnosis for Tr. vaginalis ranges from basic microscopy to nucleic acid amplification assays. Women are recommended to take biological material from the posterior vaginal fornix, men – urine, ejaculate, secret prostate.ML DILA proposes the definition of Tr. vaginalis by the gold standard method of InPouch, or the simultaneous determination of the most common 4 pathogens and 3 conditional pathogens by the method of “Screening of STIs”. Control of treatment effectiveness according to the CDC Sexually Transmitted Diseases Treatment Guidelines are recommended for all women within the first 3 months after treatment, regardless of whether they consider their sexual partners cured, which is associated with a high risk of reinfection.