From a water resource to a point pollution source: the daily journey of a coastal urban stream

The aim of this study was to understand how a stream ecosystem that flows from its fountainhead to its mouth inside a city, changes from a water resource to a point pollution source. A multidisciplinary descriptive approach was adopted, including the short-term temporal and spatial determination of physical, chemical, biological and ecotoxicological variables. Results showed that water quality rapidly decreases with increasing urbanization, leading the system to acquire raw sewage attributes even in the first hundred meters after the fountainheads. Despite the tidal circulation near the stream mouth being restricted by shallowness, some improvement of the water quality was detected in this area. The multidisciplinary evaluation showed to be useful for obtaining a more realistic understanding of the stream degradation process, and to forecast restoration and mitigation measures.

Este trabalho teve o objetivo de compreender como um ecossistema de córrego que flui desde as nascentes até sua desembocadura dentro de uma cidade, transforma-se de recurso hídrico em fonte pontual de poluição. Foi adotada uma abordagem descritiva multidisciplinar, incluindo a determinação espacial e temporal em escala diária de variáveis físicas, químicas, biológicas e ecotoxicológicas. Os resultados mostraram que a qualidade da água rapidamente diminui com o aumento da intensidade espacial de urbanização, levando o sistema a adquirir características típicas de esgoto bruto já após suas primeiras centenas de metros de curso. Apesar da circulação relacionada à maré junto a desembocadura ser restrita devido às baixas profundidades, foi registrada certa melhora na qualidade da água nessa área. A avaliação multidisciplinar se mostrou útil para obter uma compreensão mais realista do processo de degradação do córrego e para propor medidas de restauração ou mitigação dos impactos.

From a water resource to a point pollution source: the daily journey of a coastal urban stream.

The aim of this study was to understand how a stream ecosystem that flows from its fountainhead to its mouth inside a city, changes from a water resource to a point pollution source. A multidisciplinary descriptive approach was adopted, including the short-term temporal and spatial determination of physical, chemical, biological and ecotoxicological variables. Results showed that water quality rapidly decreases with increasing urbanization, leading the system to acquire raw sewage attributes even in the first hundred meters after the fountainheads. Despite the tidal circulation near the stream mouth being restricted by shallowness, some improvement of the water quality was detected in this area. The multidisciplinary evaluation showed to be useful for obtaining a more realistic understanding of the stream degradation process, and to forecast restoration and mitigation measures.

[Outbreak of respiratory syncytial virus at a neonatal intensive care unit in Mexico City]. / Brote de infección por virus sincicial respiratorio en una Unidad de Cuidados Intensivos Neonatales en la Ciudad de México.

RSV can be spread in hospital wards, being thus responsible for increased morbidity and mortality among infected patients. We describe an RSV outbreak in a Neonatal Intensive Care Unit (NICU). METHODS. As soon as the first RSV cases were detected in the NICU, every patient, as well as the personnel taking care of them, were tested; nasal washes for viral isolation, and nasopharyngeal swabs for viral antigen detection by immunofluorescence, were collected. RESULTS. Twelve patients were hospitalized. RSV was detected in eight, coinfection was observed in three of them. RSV was also detected in three adults. We describe the clinical findings among the RSV infected patients, and the infection control measures that we followed to stop the RSV spread. CONCLUSIONS. Viruses can be responsible for nosocomial infections, being thus mandatory to establish the diagnosis, treatment and infection control measures. In our NICU, the RSV infected patients had mild to moderate disease, there were no deaths attributable to RSV infection. We discuss infection control measures.