Unusual Magnetic Resonance Imaging Features of Scrub Typhus Encephalitis.

Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi. The diagnosis of scrub typhus relies on the patient's history of exposure, clinical manifestations, and results of serological tests. Our patient had a history of altered sensorium, inability to walk, and macular rashes predominantly distributed over the chest and bilateral upper limbs. Post serological testing, the patient was referred to the radiology department for MRI brain. Radiologically, MRI being a superior modality helps in the evaluation of lesions in depth, helping to simplify the diagnosis of meningitis, scrub typhus encephalitis, and other related conditions. Various findings have been described in scrub typhus encephalitis in MR brain imaging, and our case shows an unusual finding in brain imaging.

Molecular epidemiology of Giardia spp. in northern Vietnam: Potential transmission between animals and humans.

Giardia spp. is detected frequently in humans and animals. Although many studies have been conducted on the epidemiology of giardiasis, there is a scarcity of information on the genetic diversity and the dynamics of transmission of Giardia spp. in Vietnam. The zoonotic potential of Giardia spp. remains elusive. The objective of this study was to determine the genetic diversity of Giardia spp. in both humans and livestock to assess the existence of a route of infection between livestock and humans. Our goal was to assess the role animals play in the epidemiology of human infection in northern Vietnam. In Hien Khanh commune in northern Vietnam, 311 households with 1508 residents were randomly selected for a diarrheal cohort study. Of these, 2120 human diarrheal samples were collected from 1508 residents in 2014 and 2017. Of these, non-diarrheal samples were cross-sectionally collected from 471 residents. At the same site, livestock samples from buffalo, dairy and beef cattle, pigs, and dogs were collected. All stool samples were examined for Giardia spp. by Direct Immunofluorescence Assay (DFA) using fluorescent microscope. DNA extraction, PCR analysis of the 3 genes (bg, gdh, tpi), and sequencing analysis were continuously carried out. A total of 23 animal stool samples, 8 human non-diarrheal samples, and 36 human diarrheal samples were Giardia spp. were positive by PCR using the bg and gdh genes. Giardia spp. assemblage AII and E were detected in both animal samples and human samples in this study site. The detection of assemblage E in human stool samples suggests the first human case report in Vietnam. We assume that the unexpected human infection of all Giardia assemblages including A, B, and E may be due to an environment contaminated with animal and human feces in this village.

Chlamydia trachomatis Antigen Positivity in Patients with Different Ocular Manifestations over 8 Years.

Laboratory confirmation of chlamydial antigen in clinically suspected cases of chlamydial eye infections is important, as similar clinical picture can be presented by different infective or noninfective causes. We retrospectively analyzed the presence of Chlamydia trachomatis antigen in 690 clinically suspected patients over the last 8 years (2009-2016). The chlamydial antigen was detected using direct immunofluorescence assay. Overall, Chlamydia-specific antigen positivity was 45.5%. The highest positivity was seen in 2014 (68.6%) and the least in 2016 (9.4%). The antigen positivity in years 2015 (13.4%) and 2016 (9.4%) was significantly less than in all the previous study years (P < 0.0001). Antigen positivity in patients having clinical diagnosis of trachoma was significantly higher than those having other eye manifestations suggestive of chlamydial infections (P = 0.0274). Stringent surveillance both at community level and in hospital attendees is required to know the actual load of this pathogen.

Analysis of the results of 55240 children for detection of seven respiratory viruses in Guangdong Zhongshan district / 国际检验医学杂志

Objective To investigate the epidemic situation of children with respiratory viruses in zhongs-han ,Guangdong to provide evidence for the diagnosis of respiratory virus infections in children .Methods 55 240 cases were collected in a hospital from November 25 ,2011 to September 30 ,2016 ,Influenza virus(IFA , IFB) ,parainfluenza virus (PIV1 ,PIV2 ,PIV3) ,respiratory syncytial virus (RSV) and adenovirus (ADV) were detected by direct immunofluorescent ,and analyzed the results .Results The positive rate of virus infection in 55 240 children was 23 .25%,of which RSV 53 .75%,IFA 13 .83%,ADV10 .81%,PIV3 10 .77%,IFB 6 .49%, PIV1 2 .37%,PIV2 1 .14% and mixed infection 0 .84% .There were statistical significance between male and female (P＜0 .05) .The positive rates of virus infection in children 0- ≤1 years and 1- ≤3 years were higher than those in the other age groups ,the difference was statistically significant (P＜0 .05) .The positive rate of RSV was higher in both age groups (71 .92%,46 .23%) The positive rate of these 7 viruses infection in winter and spring was higher than that in summer and autumn ,the difference was statistically significant (P＜0 .05) , and the positive rate of RSV was the highest .The positive rate of these 7 viruses patients with bronchitis was higher than that of the other patients ,the difference was statistically significant (P＜0 .05) and in 108 patients with mixed infections ,the most cases was patients with RSV (90 cases) .Conclusion The main pathogen is RSV .The infection rate of children under 3 years old is the highest .Winter and spring are the high incidence of respiratory virus infection in children in Guangdong zhongshan district .

Performance evaluation of a rapid molecular diagnostic, MultiCode based, sample-to-answer assay for the simultaneous detection of Influenza A, B and respiratory syncytial viruses.

BACKGROUND: Clinical signs and symptoms of different airway pathogens are generally indistinguishable, making laboratory tests essential for clinical decisions regarding isolation and antiviral therapy. Immunochromatographic tests (ICT) and direct immunofluorescence assays (DFA) have lower sensitivities and specificities than molecular assays, but have the advantage of quick turnaround times and ease-of-use. OBJECTIVE: To evaluate the performance of a rapid molecular assay, ARIES FluA/B & RSV, using laboratory developed RT-PCR assays (LDA), ICT (BinaxNOW) and DFA. METHODS: Analytical and clinical performance were evaluated in a retrospective study arm (stored respiratory samples obtained between 2006-2015) and a prospective study arm (unselected fresh clinical samples obtained between December 2015 and March 2016 tested in parallel with LDAs). RESULTS: Genotype inclusivity and analytical specificity was 100%. However, ARIES was 0.5 log, 1-2logs and 2.5logs less sensitive for fluA, RSV and fluB respectively, compared to LDA. In total, 447 clinical samples were included, of which 15.4% tested positive for fluA, 9.2% for fluB and 26.0% for RSV, in both LDA and ARIES. ARIES clinical sensitivity compared to LDA was 98.6% (fluA), 93.3% (fluB) and 95.1% (RSV). Clinical specificity was 100% for all targets. ARIES detected 10.6% (4 fluA, 8 fluB, 11 RSV) and 26.9% (7 fluA, 3 fluB, 22 RSV) more samples compared to DFA and ICT, all confirmed by LDA. CONCLUSION: Although analytically ARIES is less sensitive than LDA, the clinical performance of the assay in our tertiary care setting was comparable, and significantly better than that of the established rapid assays.

Analysis of Viral Etiology in 3 572 patients with Acute Respiratory Tract Infections / 国际检验医学杂志

Objective To explore the viral etiology of acute respiratory tract infections in Nanping area .Methods A total of 3 572 patients ,suffered from acute respiratory tract infections from December 2012 to December 2014 were enrolled in the study .Sev‐en common respiratory viruses were detected by direct immunofluorescence assay ,including influenza A virus(IA) ,influenza B virus (IB) ,adenovirus (ADV) ,respiratory syncytial virus (RSV) ,arainfluenza type Ⅰ (P1) ,arainfluenza type Ⅱ (P2) ,arainfluenza typeⅢ (P3) .Results In total 3 572 samples ,509 samples were virus positive (14 .25% ) .Among them ,507 positive samples were single virus infections and 7 positive samples were double virus infections .RSV infection(9 .38% ) ,P3 infection(2 .32% ) and IA infection (1 .09% ) rates were the top three .Conclusion RSV was the main viral pathogen among 7 common respiratory viruses with obvious seasonal periodicity .Children′s immunity is low and need to prevent respiratory viral infections .

Identification of respiratory virus in infants with congenital heart disease by comparison of different methods / Identificação de vírus respiratórios em crianças com cardiopatia congênita por comparação de diferentes métodos

Respiratory virus infections are the main cause of infant hospitalization and are potentially severe in children with congenital heart disease (CHD). Rapid and sensitive diagnosis is very important to early introduction of antiviral treatment and implementation of precautions to control transmission, reducing the risk of nosocomial infections. In the present study we compare different techniques in the diagnosis of respiratory viruses in CHD infants. Thirty-nine samples of nasopharyngeal aspirate were obtained from CHD infants with symptoms of respiratory infection. The Multiplex PCR (Seeplex® RV 12 ACE Detection) driven to the detection of 12 respiratory viruses was compared with the direct immunofluorescence assay (DFA) and PCR, both targeting seven respiratory viruses. The positivity found by DFA, Multiplex and PCR was 33.3 percent, 51.3 percent and 48.7 percent, respectively. Kappa index comparing DFA and Multiplex, DFA and PCR and PCR and Multiplex PCR was 0.542, 0.483 and 0.539, respectively. The concordance between techniques was considered moderate. Both Multiplex PCR (p = 0.001) and PCR (p = 0.002) detected significantly more respiratory virus than DFA. As the performance of the tests may vary, the combination of two or more techniques may increase diagnostic sensitivity favoring the diagnosis of co-infections, early introduction of antiviral therapy and implementation of appropriate measures.

Infecções respiratórias virais são a principal causa de hospitalização infantil e podem ser extremamente graves em crianças com cardiopatia congênita. O diagnóstico rápido e sensível é importante para a introdução precoce de tratamento antiviral e implantação de precauções para controle da transmissão, reduzindo o risco de infecções nosocomiais. Neste estudo, comparamos o desempenho de diferentes técnicas no diagnóstico de vírus respiratórios em crianças com cardiopatia congênita e sintomas respiratórios. Trinta e nove amostras de aspirado de nasofaringe foram obtidas de crianças com sintomas de infecção respiratória. Ensaio de PCR Multiplex que detecta 12 vírus respiratórios (Seeplex® RV 12 ACE Detection) foi comparado à Imunofluorescência Direta (IFD) e à PCR específica, ambas direcionadas a sete vírus. A positividade da IFD foi 33,3 por cento, do Multiplex foi 51,3 por cento e da PCR 48,7 por cento. O índice kappa comparando IFD e Multiplex, IFD e PCR, e PCR e Multiplex foi, respectivamente, 0,542, 0,483 e 0,539, sendo a concordância considerada moderada. O Multiplex e a PCR detectaram significantemente mais vírus que a IFD (p < 0,0001 e 0,002, respectivamente). Como o desempenho dos testes varia o uso de mais de uma técnica pode aumentar a sensibilidade diagnóstica favorecendo a introdução precoce de terapia antiviral e implantação de medidas profiláticas.

Evaluation of Direct Immunofluorescence Test with PCR for Detection of Novel Influenza A (H1N1) Virus during 2009 Pandemic

During the 2009 novel influenza (H1N1) pandemic, the sensitivity of direct immunofluorescence assay (DFA) for H1N1 infection was 62% (266/429) of that of the polymerase chain reaction (PCR) test. The sensitivity of the DFA differed significantly with the age of patients: the sensitivity was the highest (71.8%) for patients aged or =30 years. The sensitivity of DFA in patients aged > or =30 years was 40.7%. Furthermore, the sensitivity (67.3%, 171/254) of DFA was higher for patients who had a high temperature at admission. An increase in the incidence of H1N1 infection did not influence the sensitivity of DFA (62.1% vs. 62%; p=0.984) test, but resulted in a decrease in the negative predictive value, from 92.4% (700/757) to 69.6% (247/355). PCR may be useful as the initial test for diagnosing H1N1 infection in patients aged > or =30 years with a normal temperature at presentation.

Detection of Respiratory Viruses in Children by Multiplex Reverse Transcriptase PCR, Direct Immunofluorescence Assay, and Shell Vial Culture / 대한임상미생물학회지

BACKGROUND: Direct immunofluorescence assay (DFA) and shell vial culture (SVC) have been used to diagnose respiratory viral infections. Recently a multiplex reverse transcriptase PCR (mRT-PCR) for 12 respiratory viruses has been introduced. We evaluated the diagnostic usefulness of these methods. METHODS: Among 275 nasopharyngeal aspirates (NPAs) received from pediatric patients during the 3-month period from May through July, 2007, 122 samples were selected so as to include diverse viruses and varying numbers of DFA-positive cells for mRT-PCR. Also, the results of the 85 NPAs that had been analyzed by both DFA and SVC were reviewed retrospectively. RESULTS: Detection rates for the seven major respiratory viruses, respiratory syncytial virus (RSV), influenza virus A and B, parainfluenza virus 1, 2, and 3, and adenovirus by DFA vs mRT-PCR were 32.0% and 55.7%, and by DFA vs SVC were 32.9% and 40.0%. A number of adenovirus detected by DFA vs mRT-PCR were 12 and 22, and by DFA vs SVC were 6 and 18. A number of RSV detected were 3 and 6, and 13 and 8, respectively. CONCLUSIONS: mRT-PCR detected the respiratory viruses at the highest rate, followed by SVC and DFA in a decreasing order. However, DFA and multiplex PCR were more sensitive than SVC for RSV, while SVC was more sensitive than the other methods for adenovirus.