Tuberculose pulmonar paucibacilar em Centros de Detenção Provisória / Paucibacillary pulmonary tuberculosis in Provisional Detention Centers

Cultura de micobactérias proporciona o crescimento de bacilos viáveis, mesmo presentes em escassa quantidade e não detectados pela baciloscopia. Neste estudo foram analisadas as amostras de escarro que apresentaram baciloscopia negativa e cultura positiva. As amostras foram coletadas de 2008 a 2013, de indivíduos detidos em Centros de Detenção Provisória de Santo André, Mauá e Diadema, Estado de São Paulo. As metodologias utilizadas foram baciloscopia por coloração Ziehl-Neelsen e cultura pelo Sistema BACTEC MGIT 960 e Ogawa-Kudoh. Dos 11.529 exames realizados, 221 (1,9 %) apresentaram baciloscopias negativas e culturas positivas. Dos 221 isolados, 166 (75,1 %) pertenciam ao Complexo Mycobacterium tuberculosis, 21 (9,5 %) micobactérias não membros do Complexo Mycobacterium tuberculosis (MNT), 33 (14,9 %) Mycobaterium sp e uma cultura mista do Complexo M. tuberculosis e M. avium. MNT mais frequentes foram M. avium (23,8 %) e M. fortuitum (19,0 %). A maioria dos isolados do Complexo M. tuberculosis (155/166 - 93,4 %) foi sensível aos antimicrobianos. Sete amostras apresentaram resistência à isoniazida e uma apresentou multirresistência à isoniazida e rifampicina. Este estudo mostra a importância da realização da cultura em escarros que apresentam baciloscopia negativa no diagnóstico da TB e micobacteriose. O tratamento tardio causa a continuidade da transmissão da doença e agravamento do quadro clínico.

Culture of mycobacteria induces the growth of viable bacillus occurring in small quantity, which are no detectable by bacilloscopy. This study aimed at identifying the mycobacteria isolates from sputum presenting negative bacilloscopy and positive culture. The samples were collected from 2008 to 2013 from criminals of Provisional Detention Centers in Santo André, Mauá and Diadema/SP. Smears were stained by Ziehl-Neelsen staining and the cultures were performed by the BACTEC MGIT 960 system and Ogawa-Kudoh culture medium. Of 11,529 isolates, 221 (1.9 %) showed negative bacilloscopy and positive cultures. Of 221 isolates, 166 (75.1 %) belonged to Mycobacterium tuberculosis complex, 21 (9.5 %) were nontuberculous mycobacteria (NTM), 33 (14.9 %) Mycobacterium sp, and one identified as a mixed culture of M. tuberculosis and M. avium complex. The most common NTM species were M. avium (23.8 %) and M. fortuitum (19.0 %). Most of the isolates (155/166-93.4 %) were susceptible to antimicrobial agents. Seven samples were resistant to isoniazid, and one presented multiresistance to isoniazid and rifampicin. This study shows the importance in performing sputum culture, when these samples are negative on bacilloscopy in diagnosing TB and mycobacteriosis. The treatment delay results in the maintenance of disease transmission and worsening of clinical symptoms.

Survey of Clinical Laboratory Practices for 2015 Middle East Respiratory Syndrome Coronavirus Outbreak in the Republic of Korea

BACKGROUND: It is crucial to understand the current status of clinical laboratory practices for the largest outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infections in the Republic of Korea to be well prepared for future emerging infectious diseases. METHODS: We conducted a survey of 49 clinical laboratories in medical institutions and referral medical laboratories. A short questionnaire to survey clinical laboratory practices relating to MERS-CoV diagnostic testing was sent by email to the directors and clinical pathologists in charge of the clinical laboratories performing MERS-CoV testing. The survey focused on testing volume, reporting of results, resources, and laboratory safety. RESULTS: A total of 40 clinical laboratories responded to the survey. A total of 27,009 MERS-CoV real-time reverse transcription PCR (rRT-PCR) tests were performed. Most of the specimens were sputum (73.5%). The median turnaround time (TAT) was 5.29 hr (first and third quartile, 4.11 and 7.48 hr) in 26 medical institutions. The median TAT of more than a half of the laboratories (57.7%) was less than 6 hr. Many laboratories were able to perform tests throughout the whole week. Laboratory biosafety preparedness included class II biosafety cabinets (100%); separated pre-PCR, PCR, and post-PCR rooms (88.6%); negative pressure pretreatment rooms (48.6%); and negative pressure sputum collection rooms (20.0%). CONCLUSIONS: Clinical laboratories were able to quickly expand their diagnostic capacity in response to the 2015 MERS-CoV outbreak. Our results show that clinical laboratories play an important role in the maintenance and enhancement of laboratory response in preparation for future emerging infections.

Comparative Evaluation of Three Homogenization Methods for Isolating Middle East Respiratory Syndrome Coronavirus Nucleic Acids From Sputum Samples for Real-Time Reverse Transcription PCR

BACKGROUND: Real-time reverse transcription PCR (rRT-PCR) of sputum samples is commonly used to diagnose Middle East respiratory syndrome coronavirus (MERS-CoV) infection. Owing to the difficulty of extracting RNA from sputum containing mucus, sputum homogenization is desirable prior to nucleic acid isolation. We determined optimal homogenization methods for isolating viral nucleic acids from sputum. METHODS: We evaluated the following three sputum-homogenization methods: proteinase K and DNase I (PK-DNase) treatment, phosphate-buffered saline (PBS) treatment, and N-acetyl-L-cysteine and sodium citrate (NALC) treatment. Sputum samples were spiked with inactivated MERS-CoV culture isolates. RNA was extracted from pretreated, spiked samples using the easyMAG system (bioMérieux, France). Extracted RNAs were then subjected to rRT-PCR for MERS-CoV diagnosis (DiaPlex Q MERS-coronavirus, SolGent, Korea). RESULTS: While analyzing 15 spiked sputum samples prepared in technical duplicate, false-negative results were obtained with five (16.7%) and four samples (13.3%), respectively, by using the PBS and NALC methods. The range of threshold cycle (Ct) values observed when detecting upE in sputum samples was 31.1-35.4 with the PK-DNase method, 34.7-39.0 with the PBS method, and 33.9-38.6 with the NALC method. Compared with the control, which were prepared by adding a one-tenth volume of 1:1,000 diluted viral culture to PBS solution, the ranges of Ct values obtained by the PBS and NALC methods differed significantly from the mean control Ct of 33.2 (both P<0.0001). CONCLUSIONS: The PK-DNase method is suitable for homogenizing sputum samples prior to RNA extraction.

Respiratory Syncytial Virus Outbreak in the Basic Military Training Camp of the Republic of Korea Air Force / 예방의학회지

OBJECTIVES: An outbreak of acute febrile illness occurred in the Republic of Korea Air Force boot camp from May to July 2011. An epidemiological investigation of the causative agent, which was of a highly infective nature, was conducted. METHODS: Throat swabs were carried out and a multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) assay was performed to identify possible causative factors. RESULTS: The mean age of patients who had febrile illness during the study period was 20.24 years. The multiplex RT-PCR assay identified respiratory syncytial virus (RSV) as the causative agent. The main symptoms were sore throat (76.0%), sputum (72.8%), cough (72.1%), tonsillar hypertrophy (67.9%), and rhinorrhea (55.9%). The mean temperature was 38.75degreesC and the attack rate among the recruits was 15.7% (588 out of 3750 recruits), while the mean duration of fever was 2.3 days. The prognosis was generally favorable with supportive care but recurrent fever occurred in 10.1% of the patients within a month. CONCLUSIONS: This is the first epidemiological study of an RSV outbreak that developed in a healthy young adult group. In the event of an outbreak of an acute febrile illness of a highly infective nature in facilities used by a young adult group, RSV should be considered among the possible causative agents.

Diagnóstico de neumocistosis en pacientes oncológicos: por la técnica de inmunofluorescencia directa / Neumocistosis in oncological patients: diagnoses for immunofluorescense direct technique

El paciente con enfermedades oncológicas tiene un alto riesgo para desarrollar infecciones respiratorias, y neumonía por Pneumocystis jirovecii. En Venezuela existen pocos estudios sobre la neumocistosis en pacientes oncológicos. El objetivo de este trabajo fue detectar la presencia de Pneumocystis jirovecii en pacientes oncológicos a través de la técnica de inmunofluorescencia directa. Se recibieron, durante 10 meses, 31 muestras respiratorias (lavado broncoalveolar, esputo espontáneo e inducido, aspirados traqueales), de ellas 8 (25,5 por ciento) resultaron positivas. La distribución por tipo de cáncer fue la siguiente: 18 tumores sólidos y 13 leucemias y linfomas. La positividad entre los grupos estudiados no fue estadísticamente significativa (P>0,05). Los exámenes de laboratorio complementarios, relacionados tampoco fueron estadísticamente significativos (P>0,05). Es necesario incluir este diagnóstico en estudio microbiológico diferencial de infecciones del tracto respiratorio inferior en pacientes con cáncer, estos pacientes cursan con una sintomatología general inespecífica y tendrán una alta posibilidad de desarrollar neumocistosis.

The patient with malignancy disease has a high risk to develop respiratory infections for Pneumocystis jirovecii pneumonia. Investigations about pneumocystosis in oncological patients in Venezuela are scarce. The objective of this work was to detect Pneumocystis jirovecii in oncological patients by the method of direct immunofluorescence technique. Thirty one respiratory specimens (bronchoalveolar lavage, spontaneous and induced sputum, and tracheal aspirates) received in 10 months, 8 specimens of them (25.5) were positive the distribution by malignancy disease was the following: 18 solid tumors, and 13 leukemias, and lymphomas. No statistically significant differences were found between the studied groups and positive results (P>0.05). The complementary laboratory tests, related to the presence of Pneumocystis, were not statistically significant either P>0.05). Is necessary to include this diagnosis in the microbiological differential study of low respiratory tract infections in oncological patients, since these patients show unspecific symptoms, and have a high possibility to develop pneumocystosis.

Directigen Flu A + B test versus viral culture and reverse transcription-PCR for diagnosis of influenza virus type A and type B

In our study, 60 sputum specimens were collected from patients suffering from upper and lower respiratory tract manifestations with a mean age of 44.5 years. Out of the 60 patients, 49 patients had developed pneumonia as a complication. In addition to 20 specimens were collected from apparently healthy subjects matching in age with the patient group. All specimens were subjected to Directigen Flu A+B assay, viral culture on Madin Darby canine kidney cell and reverse transcription-PCR [RT-PCR] for demonstration of influenza type A and B. Directigen Flu test had a detection rate of 18.3% for influenza type A and 26.6% for influenza B. Viral culture had a detection rate of 20% and 26.6% for influenza type A and influenza type B respectively. While RT-PCR had a detection rate of 16.6% and 25% for influenza virus type A and B respectively. The sensitivity, specificity and positive and negative predictive value was[66%, 0%, 72.7%, 0% for influenza A virus and 75%, 0%, 75%, 0% for influenza type B by Directigen Flu A + B test. While the resolved sensitivity, specificity and positive and negative predictive value of RT-PCR was 100%, 83.3%, 100%, 60% for influenza A virus and 100%, 93.7%, 100%, 80% for influenza type B. Directigen Flu test is rapid, easy, reliable test that can be used for diagnosis and discrimination between influenza type A and type B infections. But it lacks specificity in some patients, thus, it requires confirmation by tissue culture and RT-PCR to rule out false-positive results