Abstract INTRODUCTION Infections caused by respiratory viruses are important problems worldwide, especially in children. Human metapneumovirus (hMPV) is a respiratory pathogen and causes severe infections with nonspecific symptoms. This study reports the hMPV occurrence and dissemination in southern Brazil and compares the frequency of occurrence of this virus and the human respiratory syncytial virus (hRSV) in the epidemiological weeks in a three-year period (2009-2011). METHODS: In total, 545 nasopharyngeal (NP) specimens from individuals with Severe Acute Respiratory Syndrome (SARS) who were negative for other seven respiratory viruses were analyzed for the presence of hMPV. Human metapneumovirus was detected by direct immunofluorescence and real-time reverse transcription polymerase chain reaction. RESULTS: hMPV was detected in 109 patients from the main geographic regions of the southernmost state of Brazil, presenting similar overall prevalence in males (46.8%) and females (53.2%). Among children who were less than six years old, hMPV was detected in 99 samples of all age groups, with a higher frequency in infants who were less than one year old (45.7%) compared to all other age groups until six years. hMPV and hRSV infection occurred in almost the same epidemiological weeks (EWs) of each year, with peaks of incidence between EW 31/37 and EW 26/38 for the years 2009 and 2011, respectively. hMPV was further detected in several cases of SARS and it was the only virus detected in three deaths. CONCLUSIONS These findings indicate that hMPV is in circulation in southern Brazil and highlight the importance of diagnosing hMPV for influenza-like illness in the population.

O objetivo deste artigo é revisar e comentar as vantagens e desvantagens dos diferentes tipos de testes de detecção de Chlamydia trachomatis na rotina de laboratórios clínicos, com ênfase nas técnicas de amplificação. A Chlamydia trachomatis é considerada a bactéria sexualmente transmissível mais freqüente em países desenvolvidos e de grande impacto no sistema reprodutivo das mulheres. É o agente causador de doenças do trato urogenital, linfogranuloma venéreo (LGV), tracoma, conjuntivite de inclusão e pneumonia no recém-nascido. Um dos fatores de risco para a infecção é a prática sexual entre adolescentes. A recorrência das infecções é comum. Episódios sucessivos de infecção aumentam o risco de desenvolver seqüelas e a chance de contrair a infecção pelo vírus da imunodeficiência humana. O diagnóstico da infecção pela Chlamydia trachomatis ainda é crítico, devido à freqüência de infecções assintomáticas. As técnicas de amplificação de ácidos nucléicos permitem utilizar urina para a detecção da clamídia, simplificando a coleta. Apresentam maior sensibilidade do que a cultura e do que os testes mais utilizados, como a imunofluorescência direta e o enzimaimunoensaio. A cultura celular, utilizada como padrão- ouro, tem especificidade de 100% e sensibilidade de 70% a 85%. De acordo com o Centers for Disease Control (CDC), um diagnóstico é considerado definitivo quando positivo em cultura ou em pelo menos dois testes não-culturais distintos. Os testes de amplificação são mais dispendiosos do que os demais testes não-culturais, mas de menor custo que a cultura.

The purpose of this article is to review and comment the advantages and disadvantages of Chlamydia trachomatis tests in clinical laboratories routine, emphasizing the techniques of amplification. Chlamydia trachomatis is considered the most frequent sexually transmitted bacterium in developed countries and it has an important impact on reproductive female tract. It causes diseases on urogenital tract, venereal limphogranuloma, trachoma, conjunctivitis and newborn pnemonia. One of the main risks of infection is the sexual practice among adolescents. Repetitive episodes of infection raise the risk of developing sequel as well as the chance of getting the infection with the human immunodeficiency virus. Its hard to diagnose the infection caused by Chlamydia trachomatis because most of times there are no symptoms. Nucleic acid amplification techniques allow us to use urine to detect chlamydia. It simplifies the sampling and offers greater accuracy than bacteria culture. It is even better than tests such as direct fluorescent antibodies and immunoassay. Cellular culture as reference techniques results in 100% of specificity and 70 to 85% of sensitivity. According to the Centers for Disease Control (CDC) is considered definitive when positive culture or, at least, two non culture distint tests. Amplification tests are more expensive than other tests, but cheaper than culture.