RESUMO
Piscirickettsia salmonis is the causative agent of piscirickettsiosis, a disease that causes significant economic losses in salmonid sea farms in Chile. The objective of this study was to determine and describe the geographical distribution, seasonality and time period when P. salmonis was first detected in farms studied under the active surveillance programme for piscirickettsiosis of the National Fisheries and Aquaculture Service of Chile (SERNAPESCA), which was conducted from January 2013 to March 2017. A 0.28% prevalence of piscirickettsiosis was determined in freshwater fish and one of 58.1% in sea farms. The prevalence of P. salmonis was 61.1% in the Aysén region, 59.8% in the Los Lagos region, 5.1% in the Los Ríos region and 3.0% in the Magallanes region. In Los Lagos and Aysén, eight clusters of sea farms were identified, in space and time, as having a positive diagnosis of P. salmonis, whereas, in Magallanes, none was identified, confirming the absence of horizontal transmission or spread of the agent in this geographical area. A seasonal variation was found in the monthly prevalence of P. salmonis, with increases in Salmo salar and Oncorhynchus mykiss in summer and autumn, and in Oncorhynchus kisutch in winter, spring and summer. It was determined that the average time required to detect the agent after fish had been transferred to the sea was 105 days (minimum, 7 days; maximum, 351 days), and no differences were found either between regions or species. Thus the results obtained from the active surveillance programme have helped to increase knowledge of the epidemiology of P. salmonis.
Piscirickettsia salmonis est l'agent étiologique de la piscirickettsiose, une maladie à l'origine de lourdes pertes économiques pour la filière de la salmoniculture marine du Chili. Les auteurs présentent les résultats d'une étude visant à déterminer et à décrire la distribution géographique, les variations saisonnières et le moment où P. salmonis est détectée pour la première fois dans les fermes salmonicoles couvertes par le programme de surveillance active de la piscirickettsiose mis en oeuvre par le Service national de la pêche et de l'aquaculture (Sernapesca) du Chili de janvier 2013 à mars 2017. Les taux de prévalence de la piscirickettsiose étaient de 0,28 % chez les poissons d'eau douce et de 58,1% dans les sites marins. Au niveau des régions, le taux de prévalence de P. salmonis était de 61,1 % à Aysén, de 59,8 % à Los Lagos, de 5,1 % à Los Ríos et de 3,0 % à Magallanes. À Los Lagos et à Aysén huit groupements de fermes salmonicoles marines ont été identifiés dans l'espace et le temps comme ayant été infectés par l'agent pathogène, tandis qu'à Magallanes aucune détection n'a eu lieu, ce qui confirme l'absence de transmission horizontale et de dissémination de l'agent pathogène dans cette zone géographique. La prévalence mensuelle de P. salmonis fait ressortir une variation saisonnière, avec une prévalence accrue en été et en automne chez Salmo salar et Oncorhynchus mykiss, et en hiver, au printemps et en été chez O. kisutch. Il a été établi que le laps de temps nécessaire pour détecter l'agent pathogène après le transfert en mer des poissons était de 105 jours en moyenne (minimum 7 jours, maximum 351 jours), moyenne non affectée par la région ou l'espèce. Ces résultats ont donc permis de mieux appréhender l'épidémiologie de l'agent pathogène grâce au programme de surveillance active.
Piscirickettsia salmonis es el agente causal de la piscirickettsiosis, enfermedad que causa importantes pérdidas económicas en los centros marinos de cultivos de salmónidos de Chile. Este estudio tuvo como objetivo determinar y describir la distribución geográfica, la estacionalidad y momento de la primera detección de P. salmonis en los centros de cultivo estudiados en el programa de vigilancia activa de la piscirickettsiosis del Servicio Nacional de Pesca y Acuicultura (Sernapesca) de Chile, que se llevó a cabo entre enero de 2013 y marzo de 2017. Se determinó una prevalencia de piscicrickettsiosis del 0,28% en peces de agua dulce y del 58,1% en centros marinos. En la región de Aysén, la prevalencia de P. salmonis fue del 61,1%, en Los Lagos, del 59,8%, en Los Ríos, del 5,1%, y en Magallanes, del 3,0%. En Los Lagos y Aysén, se identificaron ocho conglomerados de centros marinos, en el espacio y en el tiempo, con diagnóstico positivo del agente, en cambio, en Magallanes no se detectó, lo cual confirma la inexistencia de transmisión horizontal y de diseminación del agente en esta área geográfica. Se observó una variación estacional en la prevalencia mensual de P. salmonis, en la cual se comprueba un alza en verano y otoño en el caso de Salmo salar y Oncorhynchus mykiss, y en invierno, primavera y verano en el caso de O. kisutch. Se determinó que la media de tiempo necesario para la detección del agente desde la transferencia de los peces al mar era de 105 días (mínimo, 7; máximo, 351 días), y no se observaron diferencias entre regiones o especies. Así los resultados contribuyen a conocer la epidemiología del agente a través del programa de vigilancia activa.
Assuntos
Monitoramento Epidemiológico/veterinária , Doenças dos Peixes/diagnóstico , Infecções por Piscirickettsiaceae/diagnóstico , Salmonidae/microbiologia , Animais , Aquicultura , Chile , Piscirickettsia , Estações do AnoRESUMO
Area management, the coordination of production and biosecurity practices across neighboring farms, is an important disease control strategy in aquaculture. Area management in aquaculture escalated in prominence in response to outbreaks of infectious salmon anemia (ISA) internationally. Successes in disease control have been attributed to the separation achieved through area-level synchronized stocking, fallowing, movement restrictions, and fomite or pest control. Area management, however, is costly; often demanding extra biosecurity, lengthy or inconveniently timed fallows, and localization of equipment, personnel, and services. Yet, this higher-order organizational structure has received limited epidemiologic attention. Chile's National Fisheries and Aquaculture Service instigated area management practices in response to the 2007 emergence of ISA virus (ISAV). Longitudinal data simultaneously collected allowed retrospective evaluation of the impact of component tenets on virus control. Spatiotemporal analyses identified hydrographic linkages, shared ports, and fish transfers from areas with recent occurrence of ISAV as the strongest predictors of virus spread between areas, though specifics varied by ISAV type (here categorized as HPR0 for the non-virulent genotypes, and HPRv otherwise). Hydrographic linkages were most predictive in the period before implementation of enhanced biosecurity and fallowing regulations, suggesting that viral load can impact spread dynamics. HPR0 arose late in the study period, so few HPRv events were available by which to explore the hypothesis of HPR0 as progenitor of outbreaks. However, spatiotemporal patterns in HPRv occurrence were predictive of subsequent patterns in HPR0 detection, suggesting a parallel, or dependent, means of spread. Better data precision, breadth and consistency, common challenges for retrospective studies, could improve model fit; and, for HPR0, specification of diagnostic test accuracy would improve interpretation.
Assuntos
Surtos de Doenças/veterinária , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/prevenção & controle , Isavirus/fisiologia , Infecções por Orthomyxoviridae/veterinária , Salmo salar , Animais , Chile/epidemiologia , Doenças dos Peixes/virologia , Pesqueiros , Estudos Longitudinais , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologiaRESUMO
The aim of this study was to investigate associations between mechanical nociceptive threshold, blood constituents, physiological measurements and locomotion score (LS) in dairy cattle with a range of LS from 1 (normal) to 5 (severely lame). The study used 213 Friesian/Friesian cross dairy cows from 12 farms. There were 40-50 cows each with LS 1-4 and 22 cows with LS 5. Each cow was restrained and her temperature and respiratory and cardiac rates were measured. Nociceptive threshold, plasma concentrations of haptoglobin, ß-hydroxybutyrate (ß-HB), cortisol, glucose, lactate, creatinine kinase activity, packed cell volume and white blood cell counts were determined. Mixed effect models were used to investigate associations between the variables measured and LS. Parity and stage of lactation were forced into all analyses and the model fit was checked by investigation of residuals. After accounting for parity and stage of lactation, nociceptive threshold was significantly lower in cattle with LS 3-5 compared with LS 1 in a dose response manner, indicating increasing hyperalgesia with increasing LS. Haptoglobin concentration was raised in all cattle with LS>1, demonstrating an inflammatory response with all levels of lameness. Cortisol and glucose concentrations were lower and ß-HB concentrations higher in cows with LS 2 compared with cows with other scores, possibly signifying metabolic challenge. Heart and respiratory rate and rectal temperature were significantly higher only in cows with LS 5, suggesting that these measurements were insensitive measures of pain or stress. It was concluded that hyperalgesia increases with increasing severity of lameness and that nociceptive pressure and haptoglobin were sensitive measures of pain from lameness.
Assuntos
Doenças dos Bovinos/patologia , Coxeadura Animal/patologia , Medição da Dor/veterinária , Limiar da Dor , Animais , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/diagnóstico , Feminino , Locomoção , Medição da Dor/métodosRESUMO
The objective of this study consisted in assessing the prevalence of erectile dysfunction (ED) and other sexual dysfunctions in a group of men who attended a prostate awareness week campaign. In total, 2715 men attended to 'Semana de la Prostata 2001' campaign and received an additional questionnaire on sexual health. The prevalence of ED, desire and ejaculatory disorders was of 41.7, 33.8 and 49.3%, respectively; however, not all of them lived these difficulties as a real sexual problem because only 918 men (37.8%) acknowledged having 'any sexual difficulty'. Only 13.7% of the attendees consulted a physician for this reason in the past. This first Argentinean study proves the high prevalence of sexual dysfunctions in our population.
Assuntos
Disfunção Erétil/epidemiologia , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Argentina/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Neoplasias da Próstata/prevenção & controle , Sexualidade , Inquéritos e Questionários , População Urbana/estatística & dados numéricosAssuntos
Eritropoetina/uso terapêutico , Síndromes Mielodisplásicas/terapia , Proteínas Recombinantes/uso terapêutico , Idoso , Contagem de Eritrócitos , Humanos , Contagem de Leucócitos , Masculino , Síndromes Mielodisplásicas/sangue , Neutrófilos/patologia , Contagem de Plaquetas , Reticulócitos/patologiaRESUMO
Macrophage-colony stimulating factor (M-CSF) has well-known effects on murine bone marrow, but its colony stimulating activity for human bone marrow is controversial. After treatment of human bone marrow with L-phenylalanine methylester (PME), macrophage-colonies (CFU-M) were induced by M-CSF in a dose-dependent fashion. The optimal concentration of recombinant human-macrophage colony stimulating factor (rhM-CSF) was 1,000 U/mL. Purified human urine M-CSF had colony stimulating activity similar to rhM-CSF. Further studies were performed to determine the factors responsible for the enhanced CFU-M formation from PME treated marrow. Compared with nylon wool and carbonyl iron monocyte depletion methods, PME eliminated significantly more monocytes and myeloid cells. This observation suggested that these cells may release hematopoietic inhibitory factors for CFU-M. Low concentrations (1%) but not normal (10%) concentrations of blood monocytes were inhibitory (mean inhibition, 48%) to CFU-M. High concentrations of monocytes (50%) augmented CFU-M colonies. HL-60 conditioned media was used to simulate secretory products of early myeloid cells. HL-60 conditioned media (1%) inhibited CFU-M formation but not granulocyte macrophage or granulocyte colonies. We conclude that M-CSF has colony stimulating activity for human marrow that can be recognized after removal of inhibitory cells by PME treatment.
Assuntos
Medula Óssea/efeitos dos fármacos , Fator Estimulador de Colônias de Macrófagos/farmacologia , Macrófagos/efeitos dos fármacos , Fenilalanina/análogos & derivados , Células da Medula Óssea , Divisão Celular/efeitos dos fármacos , Meios de Cultura/farmacologia , Humanos , Leucemia Promielocítica Aguda/patologia , Leucemia Promielocítica Aguda/fisiopatologia , Macrófagos/citologia , Monócitos/fisiologia , Fenilalanina/farmacologia , Células Tumorais Cultivadas/patologia , Células Tumorais Cultivadas/fisiologiaRESUMO
In situ hybridization for the Y chromosome (Y-ISH) was used to monitor engraftment in 10 patients with hematological malignancies who had received T cell-depleted marrow transplants from sex-mismatched donors, seven of whom were only partially HLA-matched. In the three patients who engrafted, as the peripheral counts rose, the percentage of host peripheral blood and marrow mononuclear cells decreased steadily, although host cells (less than 1%) could still be detected as late as day 252. The percentage of host granulocytes fell rapidly to less than 0.2%. Seven patients did not achieve full engraftment by day 28. Those with a low percentage of host cells (less than 1%) improved with observation or treatment with steroids, while those with a high or increasing percentage of host cells did not improve even after treatment with GM-CSF or with repeat marrow infusion without reconditioning. In one patient with graft failure, the residual host cells were predominantly CD8+ CD57+ and CD3+ CD56+, phenotypes consistent with non-MHC-restricted cytotoxic T cells. Lack of full engraftment in recipients of T cell-depleted marrow is not always associated with autologous reconstitution and does not always require retransplantation. Y-ISH may be useful for monitoring patients at high risk for graft failure in order to detect adverse trends in mixed chimerism that will alter therapy early after transplantation.
Assuntos
Transplante de Medula Óssea/patologia , Quimera/genética , DNA/genética , Depleção Linfocítica , Hibridização de Ácido Nucleico , Linfócitos T/citologia , Cromossomo Y/ultraestrutura , Adolescente , Adulto , Antígenos de Superfície/imunologia , Transplante de Medula Óssea/imunologia , Membrana Celular/imunologia , Membrana Celular/ultraestrutura , Quimera/imunologia , DNA/análise , DNA/ultraestrutura , Feminino , Citometria de Fluxo , Rejeição de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Linfócitos T/imunologia , Linfócitos T/ultraestrutura , Cromossomo Y/análiseRESUMO
Stepwise counterflow centrifugal elutriation of leukapheresed human mononuclear cells (MNC) in a Beckman JE-6B rotor and J6-M/E centrifuge yielded a population highly enriched in natural killer (NK) cells (70-75% large granular lymphocytes with 10-13 times greater NK activity) at a flow rate of 38-44 ml/min using a fixed rotor speed of 3000 rpm at 27 degrees C. However, the mean cell recovery was less than 1%. To obtain sufficient numbers of purified NK cells for adoptive immunotherapy, a strategy combining counterflow centrifugal elutriation with adherence of recombinant interleukin-2(rIL-2)-activated NK cells to plastic was developed. First, MNC were elutriated to give a twofold enrichment in NK cells, containing 22% Leu19+ cells, 18% large granular lymphocytes and 51 lytic units of activity against K562 targets as opposed to the unfractionated MNC containing 10% Leu19+ cells, 7% large granular lymphocytes and 26 lytic units of activity. The mean recovery was 80 +/- 15% (n = 10). Further enrichment was obtained by isolation of the elutriated cells that adhered to plastic after culture for 24 h in the presence of 1000 U/ml rIL-2. The initial adherent lymphokine-activated killer (A-LAK) cells represented 1-4% of total MNC, but their subsequent expansion was at least 10-22-fold during 8-14 days in culture with 1000 U/ml rIL-2. Using this strategy, 2 x 10(9) normal MNC, obtained by leukapheresis, yielded 5 x 10(8) A-LAK cells with a total of 5.7 x 10(5) lytic units of cytotoxicity against K562 and a total of 3.3 x 10(5) lytic units against Daudi targets. This enrichment method has yielded sufficient numbers of A-LAK cells to form the basis for a phase I clinical trial of adoptive immunotherapy in patients with advanced cancer.
Assuntos
Separação Celular , Imunização Passiva , Interleucina-2 , Células Matadoras Naturais/imunologia , Antígenos de Diferenciação , Adesão Celular , Células Cultivadas , Centrifugação/métodos , Testes Imunológicos de Citotoxicidade/métodos , Humanos , Células Matadoras Naturais/classificação , Células Matadoras Naturais/fisiologia , Leucaférese , Contagem de Leucócitos , FenótipoRESUMO
In vitro coculture studies were performed in five patients with severe aplastic anemia (SAA) and their normal HLA-matched donors before and after allogeneic bone marrow transplantation (BMT) to determine whether the erythropoietic function of T cells is abnormal in this disorder. These coculture studies used fresh or cryopreserved marrow T lymphocytes with fresh or cryopreserved marrow T cell-depleted target cells. Four of five aplastic patients had little or no transfusion exposure before studies. The composite results showed that, in comparison to the erythropoietic effects of normal HLA-identical marrow T lymphocytes or engrafted T lymphocytes, T lymphocytes collected from the aplastic patients before BMT consistently suppressed or failed to support CFUE and BFUE growth optimally from autologous marrow, HLA-identical marrow, or engrafted aplastic T cell-depleted marrows. This T cell abnormality was not observed in four multiply transfused leukemics and three patients with myelodysplastic syndrome. Marker analyses of SAA marrow T lymphocytes performed before and after BMT suggested that the erythropoietic functional abnormality was due to abnormal marrow T cell composition reflecting an excess of activated Tac+, T3+, T11+ lymphocytes. Collectively, these in vitro studies provide firmer in vitro evidence implicating T cells in the pathogenesis of SAA. The erythropoietic T cells abnormalities in SAA are fully corrected by allogeneic BMT.
Assuntos
Anemia Aplástica/terapia , Doenças Autoimunes/terapia , Transplante de Medula Óssea , Eritropoese , Linfócitos T Reguladores/patologia , Anemia Aplástica/imunologia , Anemia Aplástica/patologia , Antígenos de Superfície/análise , Medula Óssea/patologia , Ensaio de Unidades Formadoras de Colônias , Humanos , Leucemia/patologia , Síndromes Mielodisplásicas/patologia , Linfócitos T Reguladores/imunologia , Doadores de TecidosRESUMO
The distribution of normal cell counts (the reference range) has been determined previously for circulating neutrophils in infants from birth to 28 days of age. We have determined the reference ranges for the absolute peripheral blood lymphocyte, monocyte, and eosinophil counts obtained from 393 infants in this same cohort. Furthermore, white blood cell counts were obtained from three groups of infants with perinatal complications previously shown to be associated with abnormal neutrophil values (ABO incompatibility, n = 82; maternal hypertension, n = 68; neonatal sepsis, n = 140) and compared with the derived reference ranges; significant alterations in the distribution of cell counts were found in each of these groups at different times. Our data provide reference ranges for lymphocyte, monocyte, and eosinophil counts in the neonatal period and evidence of the effect of specific perinatal events on these cell counts.
Assuntos
Doenças do Recém-Nascido/sangue , Recém-Nascido , Contagem de Leucócitos , Incompatibilidade de Grupos Sanguíneos/sangue , Eosinófilos , Feminino , Idade Gestacional , Humanos , Hipertensão/sangue , Infecções/sangue , Linfócitos , Masculino , Monócitos , Gravidez , Complicações Cardiovasculares na Gravidez/sangue , Valores de Referência , Fatores de TempoRESUMO
To determine the usefulness of neutrophil values in diagnosing neonatal sepsis among infants at risk of neutropenia, we evaluated the pattern of sequential absolute total and immature neutrophil counts and the immature to total neutrophil (I:T) proportion over the first 5 days of life in infants with sepsis (n = 13), asphyxia neonatorum (n = 12), or delivered of mothers with pregnancy-induced hypertension (PIH) (n = 20), comparing values to references ranges previously reported by us. Neutropenia was initially present in 67% and 50% of infants with asphyxia and those whose mothers had PIH, respectively, and persisted through the first 3 postnatal days. In contrast, infants with sepsis were less likely to be neutropenic initially (38%), and neutropenia did not persist after 36 hours of age. Elevated values for the total immature neutrophil count and I:T proportion were much more likely to occur in infants with sepsis (46% and 61%, respectively) than in infants of mothers with PIH (4% and 12%) or those with asphyxia (13% and 22%). The importance of considering the perinatal history as well as the differential neutrophil count in the evaluation of neonatal neutropenia is demonstrated.
Assuntos
Agranulocitose/sangue , Asfixia Neonatal/sangue , Infecções Bacterianas/sangue , Neutropenia/sangue , Feminino , Humanos , Hipertensão/sangue , Recém-Nascido , Contagem de Leucócitos , Gravidez , Complicações Cardiovasculares na Gravidez/sangue , Risco , Fatores de TempoRESUMO
Previous studies have suggested that spontaneous diuresis may be important to the recovery from respiratory distress syndrome in preterm infants. Daily quantification of fluid intake (1) and urine output (O) were recorded, and O/I and alveolar-arterial oxygen gradients (AaDO2) were determined for sequential eight-hour periods in 10 inborn premature infants with RDS. Sequential timed-urine-plasma collections were obtained during the first four days of life to evaluate the role of hormonal and vasoactive factors in the acute phase of RDS. Diuresis (O/I greater than 0.80) occurred at 25 to 32 hours, preceded any significant improvement in AaDO2 (which occurred at 57 to 64 hours), and was associated with a 6.2 +/- 1.4% decrease in body weight. Although there was no significant change in glomerular filtration rate, plasma AVP concentrations, or urinary excretion of AVP in the infants, there were significant decreases in both plasma concentrations and urinary excretion of 6-keto-PGF1 alpha (stable metabolite of prostacyclin) in sequential studies. These results suggest that changes in renal function or AVP may not be of primary importance in the diuresis associated with RDS, and that decreasing levels of prostacyclin, a prostaglandin that increases vascular permeability and lowers blood pressure, may have an important physiologic role.
Assuntos
Diurese , Síndrome do Desconforto Respiratório do Recém-Nascido/fisiopatologia , 6-Cetoprostaglandina F1 alfa/sangue , 6-Cetoprostaglandina F1 alfa/urina , Arginina Vasopressina/sangue , Arginina Vasopressina/urina , Humanos , Recém-Nascido , Doenças do Prematuro/sangue , Doenças do Prematuro/fisiopatologia , Rim/fisiopatologia , Prostaglandinas E/sangue , Prostaglandinas E/urina , Síndrome do Desconforto Respiratório do Recém-Nascido/sangue , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Síndrome do Desconforto Respiratório do Recém-Nascido/urinaAssuntos
Bradicardia/induzido quimicamente , Doenças do Prematuro/tratamento farmacológico , Fenitoína/efeitos adversos , Convulsões/tratamento farmacológico , Relação Dose-Resposta a Droga , Coração/efeitos dos fármacos , Humanos , Recém-Nascido , Masculino , Fenobarbital/uso terapêutico , Fenitoína/administração & dosagem , Fases do SonoRESUMO
Reference ranges for absolute total neutrophils/mm3, absolute immature neutrophils/mm3, and the fraction of immature to total neutrophils (I:T proportion) during the first 28 days of life are developed from 585 peripheral blood counts obtained from 304 normal neonates and 320 counts obtained from 130 neonates with perinatal complications demonstrated to have no statistically significant effect on neutrophil dynamics. Perinatal factors other than bacterial disease which significantly alter neutrophil dynamics include maternal hypertension, maternal fever prior to delivery, hemolytic disease, and periventricular hemorrhage. The predictive value of these reference ranges in identifying bacterial disease in the first week of age varies with the neutrophil factor evaluated and the clinical setting. Neutropenia in the presence of respiratory distress in the first 72 hours had an 84% likelihood of signifying bacterial disease, whereas neutropenia in the presence of asphyxia had a 68% likelihood of signifying bacterial disease. An abnormal I:T proportion had an accuracy of 82% and 61%, respectively, in the same clinical settings. Elevations of either immature or total neutrophils were less specific. Interpretation of abnormal neutrophil factors must include consideration of both infectious and noninfectious perinatal events.
Assuntos
Doenças do Recém-Nascido/sangue , Recém-Nascido , Contagem de Leucócitos , Neutrófilos , Contagem de Eritrócitos , Feminino , Febre , Hemólise , Humanos , Hipertensão , Neutropenia/etiologia , Neutrófilos/análise , Gravidez , Complicações na Gravidez , Complicações Infecciosas na Gravidez , Estudos Retrospectivos , TexasRESUMO
The usefulness of the differential white blood cell count in distinguishing early-onset group B streptococcal disease from other causes of neonatal respiratory distress was studied in 45 infants with culture-proved infection. The initial diagnosis was hyaline membrane disease in 19 infants, wet lung syndrome 13, and other causes of respiratory distress in 13. Thirty-nine (87%) had abnormal absolute neutrophil counts, 25 with neutropenia and 14 with neutrophilia. The absolute immature neutrophil count was elevated in 19 infants (42%). Forty-one infants (91%) had an abnormal immature neutrophil to total neutrophil ratio. All infected infants were identified when both the absolute total neutrophil count and ratio were used. The differential white cell count appears to be a useful tool for screening infants presenting with respiratory distress in the first 48 hours of life and for separating early-onset group B streptococcal disease from other causes of neonatal respiratory distress.