Molecular diagnosis of opportunistic infections in the central nervous system of HIV-infected adults in Manaus, Amazonas.

Background: Opportunistic infections in the central nervous system (CNS) of people with HIV/AIDS (PLWHA) remain significant contributors to morbidity and mortality, especially in resource-limited scenarios. Diagnosing these infections can be challenging, as brain imaging is non-specific and expensive. Therefore, molecular analysis of cerebrospinal fluid (CSF) may offer a more accurate and affordable method for diagnosing pathogens. Methods: We conducted extensive real-time PCR testing (qPCR) on CSF to evaluate etiological agents in PLWHA with neurological manifestations. Primers targeting DNA from specific pathogens, including cytomegalovirus (CMV), herpes simplex virus (HSV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), John Cunningham virus (JCV), Toxoplasma gondii, and human T-lymphotropic virus types 1 and 2 (HTLV-1 and HTLV-2), were used. Results: Cerebrospinal fluid samples revealed 90 pathogens (36.7%). Toxoplasma gondii was the most frequently detected pathogen, found in 22 samples (30.5%). Other pathogens included Cryptococcus sp. (7.7%), EBV (5.3%), CMV, VZV, and JCV (4.0% each). Conclusion: Despite antiretroviral therapy and medical follow-up, opportunistic central nervous system infections remain frequent in PLWHA. Herpesviruses are commonly detected, but T. gondii is the most prevalent opportunistic pathogen in our study population. Therefore, molecular diagnosis is a crucial tool for identifying opportunistic infections, even in patients undergoing treatment.

Molecular characterization of nontuberculous Mycobacteria in a tuberculosis and HIV reference unit in the State of Amazonas, Brazil.

BACKGROUND: In recent years, the prevalence of nontuberculous mycobacterial (NTM) infections has increased in different regions of the world. The American Thoracic Society (ATS) recommends standardized identification criteria, reinforcing the need for faster and less complicated clinical and laboratory techniques. METHODS: In this retrospective study, NTM species isolated from pulmonary, extrapulmonary, and disseminated samples from patients treated at a TB/HIV reference unit in the State of Amazonas from 2011 to 2014 were identified through a combination of molecular techniques. RESULTS: To identify the molecular technique, 50 cryopreserved NTM cultures were recovered and subcultivated in culture medium. The potentially pathogenic NTM species identified were M. avium, M. intracellulare, M. kansasii, M. chelonae, M. abscessus, M. fortuitum, and M. peregrinum. Results of GenoType® showed moderate agreement with those of genomic sequencing (kappa = 0.60), whereas the results obtained by the PRA-hsp65 technique disagreed with the results obtained by sequencing (kappa = 0.49). CONCLUSIONS: Our findings highlight that GenoType CM is a good method for the identification of NTM, as well as the need for the application of standardized criteria, such as those set forth by the ATS.

Molecular characterization of nontuberculous Mycobacteria in a tuberculosis and HIV reference unit in the State of Amazonas, Brazil

ABSTRACT Background: In recent years, the prevalence of nontuberculous mycobacterial (NTM) infections has increased in different regions of the world. The American Thoracic Society (ATS) recommends standardized identification criteria, reinforcing the need for faster and less complicated clinical and laboratory techniques. Methods: In this retrospective study, NTM species isolated from pulmonary, extrapulmonary, and disseminated samples from patients treated at a TB/HIV reference unit in the State of Amazonas from 2011 to 2014 were identified through a combination of molecular techniques. Results: To identify the molecular technique, 50 cryopreserved NTM cultures were recovered and subcultivated in culture medium. The potentially pathogenic NTM species identified were M. avium, M. intracellulare, M. kansasii, M. chelonae, M. abscessus, M. fortuitum, and M. peregrinum. Results of GenoType® showed moderate agreement with those of genomic sequencing (kappa = 0.60), whereas the results obtained by the PRA-hsp65 technique disagreed with the results obtained by sequencing (kappa = 0.49). Conclusions: Our findings highlight that GenoType CM is a good method for the identification of NTM, as well as the need for the application of standardized criteria, such as those set forth by the ATS.

Neurological Manifestations Associated with Parvovirus B19 Infection in Immunocompetent Children: Case Series and Systematic Review.

An increasing number of reports have described human parvovirus B19 infection in association with a variety of neurological manifestations, especially in children. This study assessed the clinical and laboratory outcomes found in a case series of immunocompetent children who tested positive for parvovirus B19 by qualitative polymerase chain reaction assays of cerebrospinal fluid, in a tertiary referral center in the western Brazilian Amazon. We screened 178 children with clinically diagnosed central nervous system infections (meningoencephalitis). Of these, five (2.8%) were positive for parvovirus B19. A literature review also presented herein identified a further 50 cases of parvovirus B19 with neurological manifestations. Thus, even if the classic signs of parvovirus B19 infection are absent, such as the well-known rash, children with signs of neurological infection should also be evaluated for parvovirus B19 infection.

Increased sensitivity in diagnosis of tuberculosis in HIV-positive patients through the small-membrane-filter method of microscopy.

The sensitivity of microscopy for the diagnosis of tuberculosis (TB) is around 50% but decreases by about 15% in patients with suspected TB who are coinfected with HIV. Here, we compared the accuracies of three microscopy methods for processing sputum smears (concentration by centrifugation with or without N-acetyl-L-cysteine [NALC] and concentration by filtration on a polycarbonate membrane) to that of culture on Ogawa-Kudoh medium as the gold standard method. Sputum samples were obtained from 432 patients with suspected pulmonary TB, of whom 60% were infected with HIV. Analysis was performed using the first specimen. Compared to the gold standard culture, the small-membrane-filter (SMF) method was the most sensitive microscopic method. In HIV-infected TB patients, the sensitivity of the SMF method was significantly higher than those for centrifugation of sputum samples with or without NALC treatment (61.9%, 47.6%, and 45.2%, respectively; P = 0.001). Similarly, in TB patients without HIV infection, the sensitivity of the SMF method was significantly higher than those for centrifugation of sputum samples with or without NALC treatment (81.8%, 63.6%, and 57.5%, respectively; P = 0.001). In the two study groups, TB patients with or without HIV, no significant differences between the specificities of the three methods were observed. Handling of the second sputum sample similarly by centrifugation with or without NALC and by the SMF method increased positivities by 13%, 11%, and 4%, respectively. The overall agreement between microscopy and culture was above 90% for all groups. Microscopic evaluation of the sputum samples treated with NALC compared to those not treated with NALC did not show any increase in sensitivity. Altogether, the sensitivity of the SMF method is higher than those of the other two microscopic methods studied without a loss of specificity.

Evaluation of new strategies for the diagnosis of tuberculosis among pediatric contacts of tuberculosis patients.

BACKGROUND: In young children, underdiagnosis and diagnostic delay have an adverse effect on morbidity and mortality of tuberculosis (TB). This study evaluated new strategies for early TB diagnosis using an outpatient protocol in children between 0 and 5 years of age, with a recent household TB contact. METHODS: Case recruitment was performed in Manaus, Amazonas, Brazil, from 2008 to 2009. Epidemiologic and clinical data, tuberculin test, chest radiograph and 2 induced sputum respiratory samples from each participant were obtained. Laboratory diagnosis was based on Lowenstein-Jensen (LJ) culture, mycobacteria growth indicator tube (MGIT) and polymerase chain reaction. We conducted a study of comparison of diagnostic tests and a study of cases and controls to identify the clinical characteristics of the population with positive culture and polymerase chain reaction results. RESULTS: A total of 102 children were evaluated. Thirty-two fulfilled criteria of suspicion of TB. MGIT was more sensitive (P = 0.035) and faster (P < 0.001) than LJ. Clinical score, MGIT, LJ and polymerase chain reaction presented no concordance or slight concordance. A positive MGIT culture was only associated with a strong tuberculin test reaction (P = 0.026). The combination of MGIT with the clinical score allowed the diagnosis of 33% more cases with little or no symptomatology compared with the exclusive use of the clinical classification. CONCLUSIONS: The sensitivity and speed of MGIT demonstrate the utility of liquid cultures for the diagnosis in children. Furthermore, these results suggest that the use of MGIT in children presenting recent household TB contact and a strong tuberculin test reaction may be a strategy to improve early TB diagnosis.

Estudo dos fatores de risco maternos associados à sepse neonatal precoce em hospital terciário da Amazônia brasileira / Study of maternal risk factors associated with early-onset neonatal sepsis in a tertiary hospital of the Brazilian Amazonia

OBJETIVO: identificar os fatores de risco maternos envolvidos na sepse neonatal precoce, pesquisando vaginose bacteriana, microorganismos isolados em cultura de urina materna e na hemocultura do recém-nascido na sala de parto. MÉTODOS: estudo de coorte longitudinal prospectivo, envolvendo, aleatoriamente, 302 mães e seus recém-nascidos, que foram acompanhados até sete dias de vida, a fim de diagnosticar sepse. RESULTADOS: diagnosticados 16 casos (5,3 por cento) de sepse neonatal precoce. O número médio de consultas no pré-natal foi 5,2 (DP=1,8). Das 269 (89,1 por cento) grávidas que fizeram acompanhamento pré-natal, porém, 117 (43,4 por cento) fizeram mais de seis consultas; 90 (29,8 por cento) tiveram bolsa rota antes do parto, somente 22 (7,3 por cento) tinham mais de 18 horas. Cento e vinte e três grávidas (40,7 por cento) queixavam-se de corrimento vaginal, entretanto 47 (15,6 por cento) tinham vaginose bacteriana. Em 23 (7,6 por cento), foi identificada bacteriúria; duas (0,7 por cento) apresentavam febre no domicílio e 122 (40,4 por cento) fizeram antibioticoprofilaxia intraparto. Quarenta recém-nascidos (13,2 por cento) foram prematuros, 37 (12,3 por cento) com baixo peso. A avaliação do risco relativo mostrou significância para prematuridade (RR=92,9; IC95 por cento=12,6-684,7), número de consultas no pré-natal inferior a seis (RR=10,8; IC95 por cento=1,4-80,8), febre no domicílio (RR=10,0; IC95 por cento=2,3-43,5), baixo peso ao nascer (RR=21,5; IC95 por cento=7,3-63,2) e Apgar inferior a sete no quinto minuto (RR=19,5; IC95 por cento=9,0-41,9). Foram encontradas diferenças significantes no nível de 5 por cento na comparação das médias para o baixo número de consultas no pré-natal, prematuridade e baixo peso ao nascer. CONCLUSÕES: o principal microorganismo isolado na hemocultura dos recém-nascidos foi o Streptococcus agalactiae. Prematuridade, ausência de seguimento pré-natal e baixo peso ao nascer foram os fatores de risco...

PURPOSE: to identify the main maternal risk factors involved in early-onset neonatal sepsis, evaluating the risk associations between bacterial vaginosis and isolated microorganisms found in the maternal urine culture and in the newborn blood culture in the delivery room. METHODS: randomized longitudinal cohort study involving 302 mothers and their newborns. All neonates were followed up for seven days in order to diagnose sepsis. RESULTS: the outcomes were the following: 16 (5.3 percent) early-onset neonatal sepsis cases (incidence of 53 cases per 1,000 live births). The average number of prenatal appointments with a doctor was 5.2 (SD=1.8). The number of women with prenatal follow-up was 269 (89.1 percent), but only 117 (43.4 percent) of them went to six or more medical appointments, 90 (29.8 percent) had premature rupture of membranes before delivery, but only 22 (7.3 percent) had it for more than 18 hours. A total of 123 women (40.7 percent) complained of vaginal discharge, but only 47 (15.6 percent) of them had bacterial vaginosis, 92 (30.4 percent) complained of urinary infection, but only 23 (7.6 percent) of them had bacteriuria, two (0.7 percent) had fever at home, 122 (40.4 percent) received intra-partum antibiotic prophylaxis, 40 (13.2 percent) had premature delivery and 37 (12.3 percent) had low-birth-weight babies. Gestational age was a significant risk factor (RR=92.9; IC95 percent:12.6-684.7), as well as the number of prenatal appointments (RR=10,8; IC95 percent:1,4-80,8), fever (RR=10,0; IC95 percent:2,3-43,5), low-birth-weight (RR=21,5; IC95 percent:7,3-63,2) and early neonatal death (RR=89,4; IC95 percent:11,16-720,6). A significant difference of 5 percent was found in the comparison of the averages of lower number of prenatal appointments, prematurity and lower birth weight. CONCLUSIONS: the major microorganism isolated in the newborns’ blood culture was the Streptococcus agalactiae. Prematurity, lack of prenatal follow...