Natural variation of Arabidopsis thaliana responses to Cauliflower mosaic virus infection upon water deficit.

Plant virus pathogenicity is expected to vary with changes in the abiotic environment that affect plant physiology. Conversely, viruses can alter the host plant response to additional stimuli from antagonism to mutualism depending on the virus, the host plant and the environment. Ecological theory, specifically the CSR framework of plant strategies developed by Grime and collaborators, states that plants cannot simultaneously optimize resistance to both water deficit and pathogens. Here, we investigated the vegetative and reproductive performance of 44 natural accessions of A. thaliana originating from the Iberian Peninsula upon simultaneous exposure to soil water deficit and viral infection by the Cauliflower mosaic virus (CaMV). Following the predictions of Grime's CSR theory, we tested the hypothesis that the ruderal character of a plant genotype is positively related to its tolerance to virus infection regardless of soil water availability. Our results showed that CaMV infection decreased plant vegetative performance and annihilated reproductive success of all accessions. In general, water deficit decreased plant performance, but, despite differences in behavior, ranking of accessions tolerance to CaMV was conserved under water deficit. Ruderality, quantified from leaf traits following a previously published procedure, varied significantly among accessions, and was positively correlated with tolerance to viral infection under both well-watered and water deficit conditions, although the latter to a lesser extent. Also, in accordance with the ruderal character of the accession and previous findings, our results suggest that accession tolerance to CaMV infection is positively correlated with early flowering. Finally, plant survival to CaMV infection increased under water deficit. The complex interactions between plant, virus and abiotic environment are discussed in terms of the variation in plant ecological strategies at the intraspecific level.

Outbreak of canine parvovirus 2b and Clostridium difficile infection in Asian small-clawed otters.

A concurrent outbreak of infection by canine parvovirus 2b (CPV-2b) and Clostridium difficile producing A and/or B toxins occurred in Asian small-clawed otters (Amblonyx cinereus). The 5 clinically affected otters were 6- to 24-mo-old intact females that had severe diarrhea, dehydration, were acutely comatose, and died 1-4 d after the onset of clinical signs. Postmortem examination was performed in 3 of 7 otters. Macroscopically, the small intestine was diffusely reddened and contained red-to-brown, malodorous, watery digesta without formed feces (3 of 3). Histologic examination identified loss of enterocytes and necrosis of crypt epithelial cells. Denuded villi were often covered by mixed bacterial colonies with a predominance of gram-positive cocci to short rods in addition to larger gram-positive and -negative rods. There was also splenic lymphoid follicle depletion (2 of 3). Immunofluorescence assay revealed CPV antigen in enterocytes (2 of 3), mesenteric lymph nodes (3 of 3), and spleen (1 of 3). Immunohistochemistry revealed CPV antigen in enterocytes, lymphocytes, and dendritic cells of the Peyer patches and spleen (3 of 3), and lingual epithelial cells (1 of 2). CPV was isolated from tissues from 2 of 3 otters, and DNA sequencing identified CPV-2b for the 1 isolate tested. C. difficile producing A and/or B toxins were identified in the intestinal content by ELISA (3 of 3). To our knowledge, an outbreak of CPV-2b infection and C. difficile with clinically significant gastrointestinal disease has not been described previously in otters. The source of the viral infections remains unknown; however, these agents should be considered in otters and other mesocarnivores with similar clinical and pathologic findings.

Is there any difference between the symptomatology and clinical findings of viral agents causing dehydration?

BACKGROUND: Acute gastroenteritis is responsible for dehydration in many children. The viruses like rotavirus, norovirus, and adenovirus are considered the main causative agents of gastroenteritis. The goal of this study is the evaluation of the symptoms, clinical findings and hospitalization requirements in pediatric patients with dehydration secondary to viral gastroenteritis. METHODS: The distribution of age, symptoms, clinical and laboratory findings and hospitalization requirements of 156 viral acute gastroenteritis patients with moderate dehydration were evaluated retrospectively. Patients were between 3 months to 16 years of age (mean: 38.7 months). The patients were categorized into four groups according to etiological agents as rotavirus, norovirus, adenovirus, and mixed infections for the comparison of symptoms, clinical characteristics, laboratory results, seasonal distribution, treatment requirements, hospitalization unit, and hospitalization period. Age groups were categorized as 0-24 months, 25-72 months, and >72 months. Clinical characteristics of patients were analyzed for hospitalization period as <24 hours, and ≥24 hours. RESULTS: Moderate-degree dehydration was detected in 156 patients with acute gastroenteritis (156/278) caused by rotavirus (60.5%), norovirus (58%) and adenovirus (42%) respectively. The common symptoms of all patients were vomiting, diarrhea, abdominal pain and malaise, although fever was seen mostly in the patients of rotavirus. Aspartat aminotransferase (AST) was elevated in rotavirus gastroenteritis (11.5%) more than norovirus (5.4%) and adenovirus (0.8%) infections. Elevated blood urea nitrogen (BUN) levels (>20 mg/dL) were shown in 79.3%, of patients especially in rotavirus (43.8%). CONCLUSIONS: The main agents of acute gastroenteritis which caused dehydration were norovirus and rotavirus in our patients. Rotavirus was detected in most of the hospitalized patients with severe symptoms. AST was prominently elevated in rotavirus gastroenteritis. The clinical characteristics and some laboratory findings including hyperglycemia, leukocytosis, and elevated AST may be helpful in differentiating rotavirus from norovirus gastroenteritis. BUN level was insignificantly elevated in patients with rotavirus.

Costos de hospitalización por diarrea en niños durante el período de circulación de rotavirus en el Noroeste Argentino / Hospitalization costs associated with diarrhea among children during the period of rotavirus circulation in the Northwest region of Argentina

Objetivo. Evaluar los costos médicos directos, gastos de bolsillo y costos indirectos en casos de diarrea aguda hospitalizada en <5 años, en el Hospital de Niños Héctor Quintana de la provincia de Jujuy, durante el período de circulación de rotavirus en la región Noroeste de Argentina. Métodos. Estudio de corte trasversal de costos de enfermedad. Fueron incluidos todos los niños hospitalizados <5 años con diagnóstico de diarrea aguda y deshidratación durante el período de circulación de rotavirus, entre el 1/5/2013 y el 31/10/2013. La evaluación de costos médicos directos se realizó mediante la revisión de historias clínicas, y los gastos de bolsillo y costos indirectos, mediante una encuesta. Para el intervalo de confianza del 95% del costo promedio por paciente, se realizó un análisis probabilístico de 10 000 simulaciones por remuestreo (boostraping). Resultados. Fueron enrolados 105 casos. La edad promedio fue de 18 meses (desvío estándar 12); 62 (59%) fueron varones. El costo médico directo, gasto de bolsillo y pérdida de dinero por lucro cesante promedio por caso fue de AR$ 3413, 6 (2856, 35-3970, 93) (USD 577, 59), AR$ 134, 92 (85, 95-213, 57) (USD 22, 82) y de AR$ 301 (223, 28380, 02) (USD 50, 93), respectivamente. El total del costo por evento hospitalizado fue de AR$ 3849, 52 (3298-4402, 25) (USD 651, 35). Conclusiones. El valor de costo total por evento hospitalizado se encuentra dentro de lo esperado para Latinoamérica. La distribución de costos presenta una proporción importante de costos médicos directos en relación con los gastos de bolsillo (3, 5%) y costos indirectos (7, 8%).

Objective. To assess direct medical costs, out-of-pocket expenses, and indirect costs in cases of hospitalizations for acute diarrhea among children <5 years of age at Hospital de Niños "Héctor Quintana" in the province of Jujuy during the period of rotavirus circulation in the Northwest region of Argentina. Methods. Cross-sectional study on disease-related costs. All children <5 years of age, hospitalized with the diagnosis of acute diarrhea and dehydration during the period of rotavirus circulation between May 1st and October 31st of 2013, were included. The assessment of direct medical costs was done by reviewing medical records whereas out-of-pocket expenses and indirect costs were determined using a survey. For the 95% confidence interval of the average cost per patient, a probabilistic bootstrapping analysis of 10 000 simulations by resampling was done. Results. One hundred and five patients were enrolled. Their average age was 18 months (standard deviation: 12); 62 (59%) were boys. The average direct medical cost, out-of-pocket expense, and lost income per case was ARS 3413.6 (2856.35-3970.93) (USD 577.59), ARS 134.92 (85.95-213.57) (USD 22.82), and ARS 301 (223.28380.02) (USD 50.93), respectively. The total cost per hospitalization event was ARS 3849.52 (32984402.25) (USD 651.35). Conclusions. The total cost per hospitalization event was within what is expected for Latin America. Costs are broken down into direct medical costs (significant share), compared to out-of-pocket expenses (3.5%) and indirect costs (7.8%).

Hospitalization costs associated with diarrhea among children during the period of rotavirus circulation in the Northwest region of Argentina. / Costos de hospitalización por diarrea en niños durante el período de circulación de rotavirus en el Noroeste Argentino.

OBJETIVE: To assess direct medical costs, outof-pocket expenses, and indirect costs in cases of hospitalizations for acute diarrhea among children <5 years of age at Hospital de Niños "Héctor Quintana" in the province of Jujuy during the period of rotavirus circulation in the Northwest region of Argentina. METHODS: Cross-sectional study on diseaserelated costs. All children <5 years of age, hospitalized with the diagnosis of acute diarrhea and dehydration during the period of rotavirus circulation between May 1st and October 31st of 2013, were included. The assessment of direct medical costs was done by reviewing medical records whereas out-of-pocket expenses and indirect costs were determined using a survey. For the 95% confidence interval of the average cost per patient, a probabilistic bootstrapping analysis of 10 000 simulations by resampling was done. RESULTS: One hundred and five patients were enrolled. Their average age was 18 months (standard deviation: 12); 62 (59%) were boys. The average direct medical cost, out-of-pocket expense, and lost income per case was ARS 3413.6 (2856.35-3970.93) (USD 577.59), ARS 134.92 (85.95-213.57) (USD 22.82), and ARS 301 (223.28-380.02) (USD 50.93), respectively. The total cost per hospitalization event was ARS 3849.52 (3298-4402.25) (USD 651.35). CONCLUSIONS: The total cost per hospitalization event was within what is expected for Latin America. Costs are broken down into direct medical costs (significant share), compared to out-of-pocket expenses (3.5%) and indirect costs (7.8%).

OBJETIVO: Evaluar los costos médicos directos, gastos de bolsillo y costos indirectos en casos de diarrea aguda hospitalizada en <5 años, en el Hospital de Niños Héctor Quintana de la provincia de Jujuy, durante el período de circulación de rotavirus en la región Noroeste de Argentina. MÉTODOS: Estudio de corte trasversal de costos de enfermedad. Fueron incluidos todos los niños hospitalizados <5 años con diagnóstico de diarrea aguda y deshidratación durante el período de circulación de rotavirus, entre el 1/5/2013 y el 31/10/2013. La evaluación de costos médicos directos se realizó mediante la revisión de historias clínicas, y los gastos de bolsillo y costos indirectos, mediante una encuesta. Para el intervalo de confianza del 95% del costo promedio por paciente, se realizó un análisis probabilístico de 10 000 simulaciones por remuestreo (boostraping). RESULTADOS: Fueron enrolados 105 casos. La edad promedio fue de 18 meses (desvío estándar 12); 62 (59%) fueron varones. El costo médico directo, gasto de bolsillo y pérdida de dinero por lucro cesante promedio por caso fue de AR$ 3413,6 (2856,35-3970,93) (USD 577,59), AR$ 134,92 (85,95-213,57) (USD 22,82) y de AR$ 301 (223,28-380,02) (USD 50,93), respectivamente. El total del costo por evento hospitalizado fue de AR$ 3849,52 (3298-4402,25) (USD 651,35). CONCLUSIONES: El valor de costo total por evento hospitalizado se encuentra dentro de lo esperado para Latinoamérica. La distribución de costos presenta una proporción importante de costos médicos directos en relación con los gastos de bolsillo (3,5%) y costos indirectos (7,8%).

Clinical Features of Human Immunodeficiency Virus-Infected Patients Presenting with Cholera in Port-au-Prince, Haiti.

Human immunodeficiency virus (HIV) infection has been postulated to alter the natural history of cholera, including increased susceptibility to infection, severity of illness, and chronic carriage of Vibrio cholerae Haiti has a generalized HIV epidemic with an adult HIV prevalence of 1.9% and recently suffered a cholera epidemic. We conducted a prospective study at the cholera treatment center (CTC) of GHESKIO in Haiti to characterize the coinfection. Adults admitted at the CTC for acute diarrhea were invited to participate in the study. Vital signs, frequency, and volume of stools and/or vomiting were monitored, and single-dose doxycycline was administered. After counseling, participants were screened for HIV by enzyme-linked immunosorbent assay and for cholera by culture. Of 729 adults admitted to the CTC, 99 (13.6%) had HIV infection, and 457 (63%) had culture-confirmed cholera. HIV prevalence was three times higher in patients without cholera (23%, 63/272) than in those with culture-confirmed cholera (7.9%, 36/457). HIV prevalence in patients with culture-confirmed cholera (7.9%) was four times higher than the adult prevalence in Port-au-Prince (1.9%). Of the 36 HIV-infected patients with cholera, 25 (69%) had moderate/severe dehydration versus 302/421 (72%) in the HIV negative. Of 30 HIV-infected patients with weekly stool cultures performed after discharge, 29 (97%) were negative at week 1. Of 50 HIV-negative patients with weekly stool cultures, 49 (98%) were negative at week 1. In countries with endemic HIV infection, clinicians should consider screening patients presenting with suspected cholera for HIV coinfection.

EPIDEMIOLOGY OF ROTAVIRUS DIARRHEA AMONG CHILDREN AGED LESS THAN 5 YEARS IN RURAL SOUTHERN ETHIOPIA.

The objective of this study was to determine the epidemiological and clinical features of rotavirus infection among children aged less than 5 years in rural southern Ethiopia. We conducted a hospital-based, prospective study among children aged less than 5 years with acute diarrhea and moderate to severe dehydration attending the outpatient department of Gambo Rural Hospital, Ethiopia during September-November 2012. Three hundred fourteen children were included in the study, of whom 137 (43.6%) had rotavirus infection. The average age of children with rotavirus infection was lower than those without it [odds ratio (OR): 0.94]. Finding severe dehydration on skin pinch test (adjusted OR: 3.76) and having diarrhea for !3 days (adjusted OR: 2.50) were associated with rotavirus infection. The mortality rate was 4.4% among rotavirus infection children and 0% among non-rotavirus diarrhea cases (p=0.006). Rotavirus infection should be suspected in children with severe dehydration on a skin pinch test and among those presenting with diarrhea for 3 days in rural southern Ethiopia.

Aetiologies of diarrhoea in adults from urban and rural treatment facilities in Bangladesh.

The objective of our analysis was to describe the aetiology, clinical features, and socio-demographic background of adults with diarrhoea attending different urban and rural diarrhoeal disease hospitals in Bangladesh. Between January 2010 and December 2011, a total of 5054 adult diarrhoeal patients aged ⩾20 years were enrolled into the Diarrhoeal Disease Surveillance Systems at four different hospitals (two rural and two urban) of Bangladesh. Middle-aged [adjusted odds ratio (aOR) 0·28, 95% confidence interval (CI) 0·23-0·35, P < 0·001] and elderly (aOR 0·15, 95% CI 0·11-0·20, P < 0·001) patients were more likely to present to rural diarrhoeal disease facilities than urban ones. Vibrio cholerae was the most commonly isolated pathogen (16%) of the four pathogens tested followed by rotavirus (5%), enterotoxigenic Escherichia coli (ETEC) (4%), and Shigella (4%). Of these pathogens, V. cholerae (19% vs. 11%, P < 0·001), ETEC (9% vs. 4%, P < 0·001), and rotavirus (5% vs. 3%, P = 0·013) were more commonly detected from patients presenting to urban hospitals than rural hospitals, but Shigella was more frequently isolated from patients presenting to rural hospitals than urban hospitals (7% vs. 2%, P < 0·001). The isolation rate of Shigella was higher in the elderly than in younger adults (8% vs. 3%, P < 0·001). Some or severe dehydration was higher in urban adults than rural adults (P < 0·001). Our findings indicate that despite economic and other progress made, conditions facilitating transmission of V. cholerae and Shigella prevail in adults with diarrhoea in Bangladesh and further efforts are needed to control these infections.

Rotavirus disease in Germany--a prospective survey of very severe cases.

OBJECTIVE: Rotavirus (RV) gastroenteritis is a notifiable disease in Germany. The reports to the authorities contain few data concerning the severity of disease. The aims of this study were to determine incidence and outcome of very severe cases of RV disease. METHODS: Cases of very severe RV disease were collected by the German Paediatric Surveillance Unit for rare diseases (Erhebungseinheit für seltene pädiatrische Erkrankungen in Deutschland) using anonymous questionnaires based on hospitalized patients between April 2009 and March 2011. Inclusion criteria were detection of RV antigen in feces, patient aged 0-16 years and 1 or more of the following criteria: intensive care treatment, hypernatremia or hyponatremia (>155 mmol/L or <125 mmol/L), clinical signs of encephalopathy (somnolence, seizures, apnea) and RV-associated death. RESULTS: During 2 years, 130 cases of very severe RV disease were reported, 101 of 130 were verified. Seventeen patients had nosocomial infection, of whom 14 were neonates in intensive care. Among those, 12 infants had verified or suspected necrotizing enterocolitis. Eighty-four community-acquired cases were reported, median age was 10.5 months (0-108 months). The median hospital stay was 6 days, and 48 patients needed intensive care treatment. Among children less than 5 years of age, the yearly incidence of community-acquired very severe RV disease was 1.2 of 100,000 (95% confidence interval: 0.9-1.4/100,000). A total of 26 of 84 and 10 of 84 patients had severe hypernatremia or hyponatremia, respectively, and 58 of 84 patients had signs of encephalopathy. Three deaths were reported (1 nosocomial and 2 community acquired). CONCLUSIONS: RV infection in Germany can have a life-threatening course. A substantial number are nosocomial infections.

Canine distemper virus infection in fennec fox (Vulpes zerda).

Fifteen 8-month-old fennec foxes imported from Sudan showed fever, mucopurulent ocular discharge, diarrhea, severe emaciation, seizures, and generalized ataxia, and died. Three of the 15 animals were presented for diagnostic investigation. Severe dehydration, brain congestion, and gastric ulcers were observed in all animals. In one animal, the lungs had failed to collapse and were multifocally dark red in appearance. Histopathologically, there were lymphohistiocytic meningoencephalitis with malacia, mild interstitial pneumonia, lymphoid depletion of lymphoid tissues and organs, and intestinal villous atrophy with intralesional coccidia. There were many intracytoplasmic and/or intranuclear inclusion bodies in the epithelial cells of the medullary velum, lungs, liver, kidneys, trachea, pancreas, stomach, gall bladder, urinary bladder, and ureters, and in macrophages of malacia foci and lymphocytes and macrophages of lymphoid organs. Additionally, intestinal coccidia were confirmed to be Isospora species by a fecal test. To our knowledge, this is the first report of canine distemper with intestinal coccidiosis in fennec fox.

Clinical consequences of rotavirus acute gastroenteritis in Europe, 2004-2005: the REVEAL study.

BACKGROUND: The availability of comprehensive, up-to-date epidemiologic data would improve the understanding of the disease burden and clinical consequences of rotavirus gastroenteritis (RVGE) in Europe. METHODS: During the 2004-2005 season, a prospective, multicenter, observational study was conducted in children <5 years of age in primary care, emergency department, and hospital settings in selected areas of Belgium, France, Germany, Italy, Spain, Sweden, and the United Kingdom. The clinical consequences of acute gastroenteritis (AGE) and RVGE were estimated. RESULTS: The estimated percentage of children with rotavirus-positive AGE admitted to a hospital was 10.4%-36.0%, compared with 2.1%-23.5% of children with rotavirus-negative AGE. In France, Germany, Italy, Spain, and the United Kingdom, the relative risk of hospitalization was statistically significantly higher for children with rotavirus-positive AGE than for those with rotavirus-negative AGE. Children with rotavirus-positive AGE were more likely to have lethargy, fever, vomiting, and dehydration, and, therefore, more severe disease than were children with rotavirus-negative AGE. Dehydration was up to 5.5 times more likely in children with rotavirus-positive AGE than in those with rotavirus-negative AGE. CONCLUSIONS: Rotavirus-positive AGE is more severe, causes more dehydration, and results in more emergency department consultations and hospitalizations than does rotavirus-negative AGE. Variations in the management of RVGE seen across study areas could be explained by differences in health care systems. Routine rotavirus vaccination of infants could significantly reduce the substantial burden of RVGE and would have major benefits for potential patients, their families, and health care providers.

[Acute diarrheal disease: a public health challenge in Colombia]. / La enfermedad diarreica aguda: un reto para la salud pública en Colombia.

OBJECTIVES: To establish the relationship between rotavirus infection and dehydration from diarrhea in Colombian children under 5 years of age, and to identify risk factors for diarrhea with dehydration. METHODS: A case-control study was performed in an urban hospital in Bogota, Colombia, between April 2000 and February 2001. The sample was composed of 290 children of both sexes under 5 years of age; of these children, 145 of them were hospitalized for acute diarrheal disease (ADD) with dehydration (cases), and 145 had a diagnosis of ADD but no signs of dehydration (controls). All children underwent a complete physical examination. Mothers responded to a questionnaire containing items on demographic and socioeconomic variables, as well as on knowledge, attitudes, and practices with regard to hygiene, and on access to health services. RESULTS: An association was detected between diarrhea with dehydration and the presence of rotavirus in fecal samples (odds ratio [OR] = 3.46; 95% confidence interval [95% CI]: 1.71 to 7.00), birth weight < 2 600 g (OR = 7.79; 95% CI: 3.47 to 18.01), and breastfeeding for less than 3 months (OR = 3.17; 95% CI: 1.66 to 6.13). The risk of having dehydration was associated with low socioeconomic status, poor hygienic practices among the child's family members, and mother's low educational level. CONCLUSIONS: The ineffectiveness of health promotion and disease prevention activities in a population with easy access to health services set the stage for the appearance of cases of diarrhea with dehydration. Rotavirus infection plays an important role in the severity of ADD among Colombian children.

Treatment of canine parvoviral enteritis with interferon-omega in a placebo-controlled challenge trial.

Canine parvoviral enteritis continues to cause significant morbidity and mortality in dogs worldwide, and efficacious antiviral therapies are lacking. The present trial was aimed at evaluating the therapeutic efficacy of a recombinant feline interferon (type omega) preparation in the treatment of parvoviral enteritis in dogs. A double-blind, placebo-controlled challenge trial was performed in beagle pups (8-9 weeks); clinical signs, body weight, hematologic parameters, and mortality were monitored for a period of 14 days after challenge. Fourteen animals were inoculated with virulent canine parvovirus; 10 animals that developed clinical signs thereby meeting the inclusion criteria were admitted to the treatment phase in two randomly selected groups (placebo and IFN) of equal size. The IFN group received daily intravenous injections of rFeIFN-omega (2.5 MU/kg) for three consecutive days. The placebo group received daily injections of saline without IFN. Both groups of animals received individual supportive treatment consisting of adjusted diet and electrolyte solution. All five dogs in the placebo group developed fulminating enteritis with typical clinical signs and died within 10 days post-inoculation (or 6 days post-treatment). In the IFN-treated group, one animal died on day 2 after the treatment was started, whereas the other four dogs survived the challenge and gradually recovered. Our data confirm that the rFeIFN-omega can exert a significant therapeutic effect on dogs with parvoviral enteritis by improving clinical signs and reducing mortality.

Treatment of gastrointestinal viruses.

The most common enteric viruses responsible for diarrhoea are rotavirus, enteric adenoviruses, caliciviruses including the Norwalk agent and astrovirus. These infections are usually mild to moderate in severity, self-limiting and of short duration and thus, specific antiviral therapy is not recommended. The standard management of these infections is restoration of fluid and electrolyte balance and then maintenance of hydration until the infection resolves. WHO oral rehydration therapy (ORT) was introduced about 30 years ago and has saved the lives of many infants and young children. During the last 10 years it has become evident that the efficacy of ORT can be increased by reducing the osmolality of the WHO oral rehydration solution (ORS) to produce a relatively hypotonic solution. Hypotonic ORS appears to be safe and effective in all forms of acute diarrhoea in childhood. Complex substrate ORS, which is also usually hypotonic, has been shown to have increased efficacy in cholera but not in other bacterial or viral diarrhoeas. Nevertheless, the scientific rationale for using rice or resistant starch as substrate in ORS is of physiological interest. Other treatments such as hyperimmune bovine colostrum, probiotics and antiviral agents are largely experimental and have not been introduced into routine clinical practice. Cytomegalovirus (CMV) infection of the gastrointestinal tract occurs mainly in the immunocompromised although it has been reported in immunocompetent individuals. CMV infects both the oesophagus and colon to produce oesophagitis, often with discrete ulcers, and colitis, respectively. Both conditions can be treated with ganciclovir or foscarnet. Failure to respond to monotherapy is an indication to use both agents concurrently.

Rotavirus: an overview--from discovery to vaccine.

Rotavirus is the single most important cause of both nosocomially-acquired and severe, dehydrating diarrhea. It occurs with equal frequency throughout the world, regardless of the level of sanitation. After primary infection, mild or asymptomatic reinfection is common. Current management involves the use of oral rehydration therapy and early feeding of an age-appropriate diet. Cereal-based oral rehydration solutions, lactic acid bacteria, and oral immunoglobulins may play a role in future treatment. A rhesus rotavirus, quadravalent oral vaccine, currently being considered for licensure, may be given concurrently with other routine infant immunizations and has an efficacy rate of 80% against severe disease. Pediatric nurses should be aware of these recent advances in treatment and prevention, which should significantly reduce the impact of rotavirus in the near future.

Enteric pathogens in severe forms of acute gastroenteritis in Ghanaian children.

Diarrheal disease is the major cause of childhood morbidity in developing countries. Although malnutrition is known as a risk factor for severe gastroenteritis, the role of enteric pathogens in the clinical severity is unclear. The present study was conducted in well nourished Ghanaian preschool children during a 3 month period of the rainy season to assess the relationship between enteric pathogens and severe gastroenteritis. Two hundred and twenty-five children with acute gastroenteritis and 64 age-matched control children were prospectively examined for the severity of dehydration and enteric pathogens in their stools. Of the 225 children with gastroenteritis, 69.8% (157/225) had mild dehydration and 30.2% (68/225) had severe dehydration. Bacteria were similarly isolated in stool samples from children with mild and severe dehydration and controls. Rotavirus accounted for 20.6% of children with severe dehydration and was more often isolated in stools from patients with severe dehydration than those from controls. Furthermore, the mixed infections associated with rotavirus and bacteria were more often found in patients with severe dehydration than those with mild dehydration or controls. Parasites were similarly found at low incidences among the three groups. The present study implied that rotavirus was more responsible for severe gastroenteritis than bacteria or parasites. However, factors other than enteric pathogens must be sought in a considerable number of severe cases. A large scale study throughout a year is recommended to obtain more precise information that would reflect the seasonal variation of rotavirus infections.

A prospective clinical study of patients with hypernatraemic dehydration.

In a clinical prospective 3-year study of 158 children aged 2 weeks to 14 years with hypernatraemic dehydration (serum sodium 150 mmol/l or more), infants predominated (61.4%). The 158 children with hypernatraemia accounted for 13.7% of all children admitted with gastroenteritis over the same period, and significant aetiological factors included the use of artificial feeds, differences between the children with hypernatraemia and those with normo- or hyponatraemia, P < 0.001, P < 0.001, respectively; the use of breast milk, P < 0.001, P < 0.001, respectively; nutritional status, P < 0.001, P < 0.001, respectively; and clinical state of mild to moderate dehydration P < 0.001; P < 0.001, respectively; but not with patients considered severely dehydrated. There was also a significant difference between the presence of neurological features in hyper- and normonatraemic patients P < 0.001; in hyper- and hyponatraemic patients P < 0.05, and in mortality rate between hyper- and normonatraemic patients, P < 0.05 but not between hyper- and hyponatraemic patients. A history of refusal to feed or vomiting was obtained in 41 children (25.9%). The mean serum sodium was 155.5 mmol/l (range 150-189 mmol/l); mean serum urea 7.7 mmol/l (range 1-18.9 mmol/l). Hypernatraemic dehydration remains an important and serious complication of childhood gastroenteritis in our area of study. The use of artificial milk feeds is contributory, and well-nourished babies appear more at risk. We recommend more liberal water intake during gastroenteritis and the public should also be educated on and made more aware of this condition.

Dehydration deaths in infants and young children.

Dehydration in developed countries is an uncommon but important mechanism resulting in the death of infants and children. The clinicopathological features of a series of 37 fatal dehydration cases autopsied at the Adelaide Children's Hospital over a 33-year period (1961-1993) are presented. Causative factors for dehydration included gastroenteritis (21 cases), gastroenteritis with high environmental temperature (one case), high environmental temperatures (six cases), neglect/failure to thrive (four cases), mental retardation/chromosomal abnormality (three cases), congenital adrenal hyperplasia (one case), and unsuspected cystic fibrosis (one case). The mean age at death was 11.4 months (range 2 weeks to 6.25 years; median 6 months; 95% confidence interval 6 months to 1 year and 4 months; male-to-female ratio, 19:18). Sixteen of the 22 cases of fatal gastroenteritis (73%) occurred during the fall/winter months (March to August). There were a total of seven aboriginal or part aboriginal children in the group (19%). Children with mental retardation were at higher risk of dehydration, and previously unsuspected cases of child abuse/neglect also presented with lethal dehydration. Vitreous humor electrolyte levels and immunoassay for rotavirus were useful diagnostic adjuncts.

Homotypic immune response to primary infection with rotavirus serotype G1.

Some aspects of rotavirus humoral immunity were assessed on the basis of distinguishing serotype-specific specificities (VP4/VP7) by using rotavirus reassortants, human and animal strains in neutralization assays in serum samples obtained during the acute phase, and 1, 6 and 12 months after primary natural infection. In this study, all the infecting virus strains were characterized as G type and some also as P type. Primary natural infection induces a significantly greater homotypic neutralization response than heterotypic response. In addition, there was no significant difference in the number of homotypic or heterotypic responses following reinfection. Transplacentally acquired homotypic antibodies were associated with protection against dehydration during rotavirus gastroenteritis.