RESUMO
OBJECTIVES: Stringent measures have been implemented in Hong Kong to prevent human infections due to avian influenza viruses (AIVs). Here, we report the seroprevalence of AIVs among high risk population. METHODS: In this prospective study, blood samples were collected in October and November 2013 and in July 2014 from workers at live poultry market (LPM) and pig/cattle slaughterhouse (SH) in Hong Kong. Serum antibody titers against A(H5N1), A(H7N9) and A(H9N2) were determined. RESULTS: When an hemagglutination inhibition (HI) titer of 40 was used as the cutoff, the A(H5N1) seropositive rate among LPM workers increased from 0% in 2013 to 37.8% in 2014 (P < 0.001) and the A(H9N2) seropositive rate increased from 10% to 55.6% (P < 0.001). There was no significant increase in A(H7N9) seropositive rate for LPM workers irrespective of cutoff titer. For SH workers, there was no significant increase in HI titer for any AIVs. Significantly more LPM workers had a ≥4-fold increase in A(H5N1) HI titer from 2013 to 2014 than SH workers (60% vs 8.3%, P = 0.020). CONCLUSIONS: There was a significant increase of serum A(H5N1) and A(H9N2) HI titers among Hong Kong LPM workers between 2013 and 2014. Although we cannot exclude some degree of antibody cross-reactivity with other influenza viruses, our results suggest the occurrence of subclinical AIV infections in this population.
Assuntos
Controle de Doenças Transmissíveis/métodos , Transmissão de Doença Infecciosa , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Exposição Ocupacional , Aves Domésticas , Zoonoses/epidemiologia , Animais , Anticorpos Antivirais/sangue , Bovinos , Feminino , Testes de Inibição da Hemaglutinação , Hong Kong/epidemiologia , Humanos , Virus da Influenza A Subtipo H5N1/imunologia , Subtipo H7N9 do Vírus da Influenza A/imunologia , Vírus da Influenza A Subtipo H9N2/imunologia , Influenza Aviária/prevenção & controle , Influenza Aviária/transmissão , Influenza Humana/prevenção & controle , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Soroepidemiológicos , Zoonoses/prevenção & controleRESUMO
OBJECTIVES: Middle East respiratory syndrome coronavirus (MERS-CoV) has emerged to cause fatal infections in patients in the Middle East and traveler-associated secondary cases in Europe and Africa. Person-to-person transmission is evident in outbreaks involving household and hospital contacts. Effective antivirals are urgently needed. METHODS: We used small compound-based forward chemical genetics to screen a chemical library of 1280 known drugs against influenza A virus in Biosafety Level-2 laboratory. We then assessed the anti-MERS-CoV activities of the identified compounds and of interferons, nelfinavir, and lopinavir because of their reported anti-coronavirus activities in terms of cytopathic effect inhibition, viral yield reduction, and plaque reduction assays in Biosafety Level-3 laboratory. RESULTS: Ten compounds were identified as primary hits in high-throughput screening. Only mycophenolic acid exhibited low EC50 and high selectivity index. Additionally, ribavirin and interferons also exhibited in-vitro anti-MERS-CoV activity. The serum concentrations achievable at therapeutic doses of mycophenolic acid and interferon-ß1b were 60-300 and 3-4 times higher than the concentrations at which in-vitro anti-MERS-CoV activities were demonstrated, whereas that of ribavirin was â¼2 times lower. Combination of mycophenolic acid and interferon-ß1b lowered the EC50 of each drug by 1-3 times. CONCLUSIONS: Interferon-ß1b with mycophenolic acid should be considered in treatment trials of MERS.
Assuntos
Antivirais/farmacologia , Doenças Transmissíveis Emergentes/virologia , Infecções por Coronavirus/virologia , Coronavirus/efeitos dos fármacos , Animais , Chlorocebus aethiops , Doenças Transmissíveis Emergentes/tratamento farmacológico , Infecções por Coronavirus/tratamento farmacológico , Surtos de Doenças , Descoberta de Drogas/métodos , Ensaios de Triagem em Larga Escala/métodos , Humanos , Interferons/farmacologia , Ácido Micofenólico/farmacologia , Ribavirina/farmacologia , Células Vero , Carga Viral/efeitos dos fármacos , Ensaio de Placa ViralRESUMO
Pneumocystis colonization has been associated with airway inflammation and obstruction. We conducted a retrospective cohort study to investigate the clinical significance of Pneumocystis in the airway of patients with active tuberculosis. Of the 108 respiratory specimens tested positive for M. tuberculosis by polymerase chain reaction (PCR), 11 (10.2%) were also positive for Pneumocystis by PCR. Compared with patients tested negative for Pneumocystis, those with Pneumocystis had a higher serum alanine transaminase level, a greater likelihood of requiring oxygen supplementation, and a worse 30-day mortality. The proportion of patients with chronic obstructive pulmonary disease was not significantly different between the 2 groups, but lung malignancy was more prevalent among patients with Pneumocystis. Multivariate analysis showed that Pneumocystis was independently associated with oxygen supplementation. Our study has shown an association between the detection of Pneumocystis in lower respiratory tract specimens and greater impairment of pulmonary function among patients with active tuberculosis.