Diagnosis of foot-and mouth disease by real time reverse transcription polymerase chain reaction under field conditions in Brazil.

BACKGROUND: Foot-and-mouth disease (FMD) is an economically important and highly contagious viral disease that affects cloven-hoofed domestic and wild animals. Virus isolation and enzyme-linked immunosorbent assay (ELISA) are the gold standard tests for diagnosis of FMD. As these methods are time consuming, assays based on viral nucleic acid amplification have been developed. RESULTS: A previously described real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay with high sensitivity and specificity under laboratorial and experimental conditions was used in the current study. To verify the applicability of this assay under field conditions in Brazil, 460 oral swabs from cattle were collected in areas free of FMD (n = 200) and from areas with outbreaks of FMD (n = 260). Three samples from areas with outbreaks of FMD were positive by real-time RT-PCR, and 2 of those samples were positive by virus isolation and ELISA. Four other samples were considered inconclusive by real-time RT-PCR (threshold cycle [Ct] > 40); whereas all 200 samples from an area free of FMD were real-time RT-PCR negative. CONCLUSION: real-time RT-PCR is a powerful technique for reliable detection of FMDV in a fraction of the time required for virus isolation and ELISA. However, it is noteworthy that lack of infrastructure in certain areas with high risk of FMD may be a limiting factor for using real-time RT-PCR as a routine diagnostic tool.

Hematologic disorders in trauma patients during parenteral alimentation with lipids

Total parenteral nutrition with lipids is a well-accepted modality of metabolic support in seriously ill trauma patients. Intolerance to lipid administration is unusual when dosage limits are not exceeded, and few hematologic disturbances have been recorded with modern fat emulsions. In the course of intravenous alimentation of six adults admitted for traumatic lesions, eosinophilia with or without leukocytopenia was noticed after periods of four days to five weeks. Principal clinical events and hematologic derangements were documented in this population. Sepsis was not always present in the patients by the time of the complication, and in those that did require antibiotics and other drugs, the prescription remained unchanged along the episode. Discontinuation of the nutritional regimen with lipids was followed by normalization of the hematologic profile, suggesting that an acute or sub-acute allergic reaction was responsible. The appearance of skin rash in two occasions reinforces this hypothesis, and the possibility of hemophagocytosis merits consideration in two of the cases who displayed reversible acute leukocytopenia. It is concluded that blood cell aberrations are possible during intravenous feeding with lipids in trauma subjects, but tend to respond to suppression of the lipid-containing nutritional prescription.