BACKGROUND In 2022, an outbreak of mpox that started in European countries spread worldwide through human-to-human transmission. Cases have been mostly mild, but severe clinical presentations have been reported. In these cases, tecovirimat has been the drug of choice to treat patients with aggravated disease. OBJECTIVES Here we investigated the tecovirimat susceptibility of 18 clinical isolates of monkeypox virus (MPXV) obtained from different regions of Brazil. METHODS Different concentrations of tecovirimat were added to cell monolayers infected with each MPXV isolate. After 72 hours, cells were fixed and stained for plaque visualization, counting, and measurement. The ortholog of F13L gene from each MPXV isolate was polymerase chain reaction (PCR)-amplified, sequenced, and the predicted protein sequences were analyzed. FINDINGS The eighteen MPXV isolates generated plaques of different sizes. Although all isolates were highly sensitive to the drug, two showed different response curves and IC50 values. However, the target protein of tecovirimat, F13 (VP37), was 100% conserved in all MPXV isolates and therefore does not explain the difference in sensitivity. MAIN CONCLUSIONS Our results support screening different MPXV isolates for tecovirimat susceptibility as an important tool to better use of the restricted number of tecovirimat doses available in low-income countries to treat patients with mpox.

BACKGROUND The high demand for adequate material for the gold standard reverse transcription real-time polymerase chain reaction (RT-qPCR)-based diagnosis imposed by the Coronavirus disease 2019 (COVID-19) pandemic, combined with the inherent contamination risks for healthcare workers during nasopharyngeal swab (NP) sample collection and the discomfort it causes patients, brought the need to identify alternative specimens suitable for the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). OBJECTIVES The aim of this work was to compare saliva and gingival fluid swabs to NP swabs as specimens for RT-qPCR-based SARS-CoV-2 diagnosis. METHODS We compared gingival fluid swabs (n = 158) and saliva (n = 207) to the rayon-tipped NP swabs obtained from mild-symptomatic and asymptomatic subjects as specimens for RT-qPCR for SARS-CoV-2 detection. FINDINGS When compared to NP swabs, gingival fluid swabs had a concordance rate of 15.4% among positive samples, zero among inconclusive, and 100% among negative ones. For saliva samples, the concordance rate was 67.6% among positive samples, 42.9% among inconclusive, and 96.8% among negative ones. However, the concordance rate between saliva and NP swabs was higher (96.9%) within samples with lower cycle threshold (Ct) values (Ct > 10 ≤ 25). MAIN CONCLUSIONS Our data suggests that whereas gingival fluid swabs are not substitutes for NP swabs, saliva might be considered whenever NP swabs are not available or recommended.

O vírus linfotrópico de células T humanas do tipo I (HTLV-I) pode causar uma doença neurológica inflamatória, crônica e incapacitante, que acomete a medula espinhal, denominada mielopatia associada ao HTLV-I/paraparesia espástica tropical (PET/MAH). A verificação de anticorpos da classe G (IgG) anti-HTLV-I no soro e no líquido cefalorraquidiano (LCR) representa importante parâmetro para o diagnóstico laboratorial da PET/MAH. OBJETIVO: Avaliação crítica dos métodos utilizados para verificação da presença e da produção intratecal de anticorpos totais e anti-HTLV-I no LCR para o diagnóstico de PET/MAH. MÉTODO: Realizou-se uma revisão sistemática de artigos da literatura médica, usando-se palavras-chave da língua inglesa como cerebrospinal fluid, intrathecal synthesis of antibodies, HTLV-I, HAM/TSP. As bases de dados utilizadas incluíram Pubmed, Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs), MEDlars onLINE (Medline) e Cochrane Library. RESULTADO: Foram selecionados 14 artigos: cinco relacionados com a presença do anticorpo IgG específico no LCR; nove sobre síntese intratecal de anticorpos totais (IgG ou IgG/IgA/IgM) e específicos anti-HTLV-I (IgG ou IgM). DISCUSSÃO: O estudo isolado da presença de anticorpo IgG anti-HTLV-I no LCR não discrimina a fração produzida no sistema nervoso central (SNC), possui baixa especificidade (40%) para o diagnóstico de PET/MAH. A demonstração da síntese intratecal de anticorpos IgG anti-HTLV-I possui maior relevância por suas elevadas especificidade (89%) e sensibilidade (83%). Entre os métodos para a avaliação da síntese intratecal de anticorpo específico, destaca-se o índice de IgG anti-HTLV-I, segundo Reiber e Felgenhauer(18), o qual se baseia no teste do ensaio imunossorvente ligado à enzima (ELISA), com análise simultânea do LCR e do soro. Outros estudos utilizam pequenas amostragens e não demonstram sensibilidade e especificidade no teste do LCR. Apenas um trabalho possui análise estatística. CONCLUSÃO: Existe a necessidade da padronização de métodos para o diagnóstico imunológico do LCR na PET/MAH, com base em testes de elevadas sensibilidade e especificidade.

The human T-cell lymphotropic virus type I (HTLV-I) may cause HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP), an incapacitating chronic inflammatory disease of the spinal cord. The detection of IgG anti-HTLV-I antibodies in the serum and cerebrospinal fluid (CSF) has been an important parameter for the laboratorial diagnosis of HAM/TSP. OBJECTIVE: critical evaluation of the methods applied to detect the presence and intrathecal production of total antibodies and anti-HTLV-I in the CSF for the diagnosis of HAM/TSP. METHODS: We performed a systematic review of medical articles by using the key words: "cerebrospinal fluid, intrathecal synthesis of antibodies, HTLV-I associated myelopathy, HTLV-I, HAM/TSP". The used databases included: PubMed, Lilacs, Medline and Cochrane Library. RESULTS: A total of 14 articles were selected: five studies were related to the presence of specific IgG antibody in the CSF and nine studied the intrathecal synthesis of total antibodies (IgG or IgG/IgA/IgM) and specific anti-HTLV-I (IgG or IgM). DISCUSSION: The isolated study of the presence of IgG antibody anti-HTLV-I in the CSF does not show the fraction produced in the central nervous system, which represents low specificity (40%) for the diagnosis of HAM/TSP. The demonstration of the intrathecal synthesis of IgG anti-HTLV-I antibodies is more relevant due to its high specificity (89%) and sensibility (83%). According to Reiber & Felgenhauer (1987), the index IgG anti-HTLV-I, which is based on ELISA test with simultaneous CSF and serum analysis, stands out from the other methods applied to evaluate the intrathecal synthesis of specific antibody. Other studies use small samples and do not demonstrate the sensibility and specificity of the test in the CSF. Only one study shows statistical analysis. CONCLUSION: The immunological diagnosis of the CSF in HAM/TSP requires the standardization of methods, which should be based on tests of high sensibility and specificity.