Hygiene habits and carriers in families with a child who has had typhoid fever

The relationship between asymptomatic shedding of bacterial enteropathogens and the hygiene habits of families who have had a child with typhoid fever (TF) are investigated. The sample was made up of 80 families: 40 families in which one child had had TF (Group A) and 40 in which no children or either of the parents had had a history of TF (Group B). In each group 20 families belonged to a low socioeconomic status (SES) and 20 to a high SES. A structured interview was used to evaluate the SES and the hygiene habits of the child; observations were made to measure the hygiene habits of the family (toilet, kitchen and food preparation) and bacteriological studies (fecal samples and hand markers). Results show that carriers were more frequent in Group A than in Group B. The bacterial species found were significantly more numerous in Group A than in Group B (fecal samples: E. coli, the classic serotypes, Shigella ssp, and hand markers: E. coli). Families of Group A had higher carriage rates than those of Group B. Finally there exists a significantly higher association between inadequate hygiene habits and carrier families. These results show the need to teach specific habits of proper hygiene to the entire population, because the fact of belonging to the high SES does not in itself preclude inadequate hygiene habits.

Liquid and protein dynamics using a new minimally invasive pleural catheter in rabbits

To obtain continuous access to the pleural space without causing injury, we tested a new transdiaphragmatic pleural catheter for its ability 1) to drain the pleural space without injury and 2) to drain liquid at a rate equal to normal pleural liquid production. In 13 anesthetized rabbits, we opened the abdomen and dissected through the diaphragm to insert a flared-tip catheter into the ventral pleural space on one side and then turned the rabbit prone. In 10 of the rabbits (8 for 6 h, 2 for 24 h), we continuously collected draining pleural liquid, and in 3 rabbits (6 h), we did not open the catheter. We injected radiolabeled albumin intravenously as a protein marker. Terminally, we collected pleural liquid from both pleural spaces and lavaged for total radioactivity. In 14 awake control rabbits without catheters, we measured normal pleural liquid production by the rate of equilibration of radiolabeled albumin from plasma to pleural liquid. We found that, although the percentage of neutrophils was increased on the side with the catheter (54 vs. 1% in control rabbits), the pleural liquid volume, protein concentration, specific activity of albumin, and total radioactivity in the pleural space were the same on the side with the catheter as on the opposite side and in the control rabbits. The liquid flow rate through the catheter over 6 h was 53 +/- 23 microliters/h [0.017 +/- 0.008 (SD) ml.kg-1.h-1], which was not significantly different from the computed rate of normal pleural liquid production in the control rabbits, 49 +/- 14 microliters/h (0.016 +/- 0.004 ml.kg-1.h-1).(ABSTRACT TRUNCATED AT 250 WORDS)

[Application of a model for predicting morbidity in children from a low socioeconomic level]

An instrument to be used at a primary health care level was built on the basis of a predictive model for diarrhea obtained during a previous study. The instrument was applied to 720 mothers or caregivers of infants living in the Southeastern area of Santiago. 83 infants who fulfilled the requisites of the instrument were surveyed during July-August 1989 and compared to age, nutritional and socioeconomic status matched children not fulfilling the same requisites. Infants selected by the predictive instrument suffered 4 times more morbid episodes and respiratory infections and 5 times more diarrheal episodes than controls. Symptoms were present in them during 50% of the survey period as opposed to 14% in controls. Mothers of children at risk had inadequate behaviors in respect to health care of their children and did not follow many of the National Health programs available for their families. The predictive instrument tested may be useful to identify children at high risk of morbidity, creating the possibility for special interventions in them.

Persistent diarrhoea in the community. Characteristics and risk factors

In 58 previously well-nourished patients who were fed cow's milk and who later developed persistent diarrhoea (greater than or equal to 15 days), data obtained during the first 8 days of acute diarrhoea were compared with those of patients whose episodes lasted less than or equal to 8 days. Children with persistent diarrhoea weighted less at birth, passed greater than or equal to 6 stools/day during the first 48 hours, received early treatment with antibiotics. Their milk feedings were stopped during the first 48 hours, they had a past history of digestive diseases and hospitalizations, they were brought in for consultation after 5 days of symptoms and their nutritional status deteriorated more (p less than 0.003, p less than 0.03, p less than 0.0001, p less than 0.0001, p less than 0.0001, p less than 0.002, p less than 0.0001, and p less than 0.03, respectively). Their mothers were significantly younger (p less than 0.0013), had better schooling (p less than 0.037), and fewer children (p less than 0.044), and were separated from the index child during the day more often (p less than 0.056). After persistent diarrhoea was diagnosed, enteropathogens in stools or lactose intolerance or both were demonstrated in 75.9%. Treatment induced remission in all cases. Using logistic regression a predictive model was established which enables us to identify, among patients with acute diarrhoea, those at risk of prolonging their illness.

Developmental changes in pleural liquid protein concentration in sheep

The source of normal pleural liquid is thought to be the systemic circulation of the pleural membranes rather than the pulmonary circulation of the nearby lung. Evidence for a systemic origin comes from the low protein concentration of pleural liquid in adult sheep, which is consistent with protein sieving from a high-pressure circulation. During normal development from fetal to adult life, systemic vascular pressure increases. We therefore reasoned that if pleural liquid comes from the systemic circulation, pleural liquid protein concentration relative to plasma protein concentration should decrease during normal development. To test this hypothesis we did thoracotomies on 14 fetal, 9 newborn, and 15 adult sheep and collected pleural liquid and plasma for measurement of total protein and albumin concentrations. In separate experiments we measured steady-state systemic and pulmonary vascular pressures in age-matched chronically instrumented fetal, newborn, and adult sheep. The protein concentration in pleural liquid relative to that in plasma (pleural liquid/plasma) decreased progressively with age (fetuses, 0.50 +/- 0.15 [SD]; newborns, 0.27 +/- 0.08; adult, 0.15 +/- 0.05); the trend was similar for pleural liquid/plasma albumin ratios as a function of age. Systemic arterial pressure increased progressively during development, whereas pulmonary arterial pressure decreased from the fetus to the adult sheep. These observations support the hypothesis that normal pleural liquid originates from a systemic circulation.

[Cryptosporidiosis: studies in children in communities of low socioeconomic level]

Cryptosporidium was detected in 2 (1.5%) out of 132 children under 2 years with acute diarrhea; in 2 (3.2%) out of 63 patients under 2 years with persistent diarrhea; in 1 (3.9%) out of 26 malnourished patients younger than 2 years with an episode of acute diarrhea and in 7 (1.4%) out of 516 pediatric ambulatory patients who consulted for acute or chronic diarrhea or recurrent abdominal pain. The clinical histories of the 5 infants with cryptosporidiosis who belonged to the first 3 studies, are presented. All they had prolonged diarrhea (more than 15 days long), and one of them showed low IgG and IgA serum concentrations, but normal proportions of T lymphocyte populations.

Typhoid fever in children of low and high socioeconomic strata: comparison of hygiene habits

The relationship between the hygienic habits of children who had typhoid fever (TF) who had recently begun attending school and their family group, is assessed. It is supposed that children, independently of their SES, acquired TF because of inadequate habits which facilitated the oral-fecal cycle. The sample was formed of 40 child-mother dyads: 20 of low SES (group A) and 20 of high SES (group B), the child of each of which had had TF. Results showed that the hygienic habits of children with respect to the oral-fecal cycle, their perception of school toilet cleanliness as well as the mothers' explanation of their children's hygienic habits is very similar in the two groups. The importance of these results is that the SES is seem to be irrelevant in the case of TF but that the hygienic habits of the children are of importance. Public health policy should be modified to include the teaching of proper hygienic habits (oral-fecal cycle).

[Trial of milk with low-lactose contents in acute diarrhea]

Fifty infants with acute diarrhea (less than or equal to 5 days of duration) were refed with either a low-lactose formula (experimental group, N = 25) or whole powdered cow's milk (control group, N = 25). During a two-month follow up etiology, clinical course, changes of anthropometric parameters and tolerance to the milk products were evaluated. The etiology of diarrhoea, the mean duration of the episodes (3.6 +/- 1.9 and 3.9 +/- 1.9 days in the experimental and control group, respectively) and the clinical course were comparable in both groups. Nutritional parameters remained unchanged during and after the episode. In two children (8.3%) of the control group stools continued to be liquid, fecal pH was 5 and reducing substances were positive. They had to be refed with the low-lactose product to induce remission of the symptoms. Both products were well tolerated. These findings suggest that availability of low-lactose formulae may be advantageous in the clinical management of infants with acute diarrhea and evidence of lactose intolerance.

[Modular diet and parenteral support in persistent diarrhea]

Eleven infants with protracted diarrhea were treated with modular diet and short-term parenteral nutrition. Mean age at admission was 3.7 months with males predominating. Enteropathogenic E. coli, classic serotypes, were isolated from 7 patients and rotavirus from one. A child with combined, severe immunodeficiency died. Milk protein intolerance was diagnosed in another patient. Balance studies and peroral biopsies were performed. Malnutrition was more frequent and hospital stay was longer in those infants who developed nosocomial infections. Even though this treatment shortened the duration of the hospitalization, the negative nutritional impact persisted: Weight/Age (NCHS) decreased from 84% to 61%, with rapid recovery after discharge. Fecal lactic acid excretion was increased on admission to 1,296 mg x day and disaccharidase activity was decreased. The modular diet decreased both fecal volume and lactic acid excretion.

Effect of an acidified milk on diarrhoea and the carrier state in infants of low socio-economic stratum

The effect on diarrhoeal disease of an acidified, modified powdered cow's milk infant formula (Pelargon) was evaluated in 82 infants (Group I) for six months; 104 infants who received the same formula but non acidified, served as controls (Group II). Nutritional status remained satisfactory in both groups throughout the observation period. Some children rejected the taste of the acidified milk. The incidence of diarrhoea was lower in Group I (p less than 0.001). The proportion of days in which the children suffered from acute diarrhoea, and the duration of the episodes were also lower in the children given the acidified milk (p less than 0.001). The rate of detection of enteropathogens and the species identified were comparable in both groups. Carrier rates for bacterial enteropathogens fell over time in Group I while they rose in Group II (p less than 0.001). Carrier rates for enteric parasites were comparable to those expected in our setting for this age group. These results suggest that acidified milk exerts a protective effect against diarrhoeal disease.

[Retrospective evaluation of persistent diarrhea at a primary health service]

Information about persistent diarrhea is scarse despite the fact that it is a frequent cause of death in children who live in developing countries. The 36,358 pediatric consultations performed at a Primary Health Care Center in Southeastern Santiago in 1984 were retrospectively evaluated. Diarrheic syndromes represented 5.1% of consultations and corresponded to 909 episodes; of these, 6.3% were cases of persistent diarrhea (greater than 15 days). The highest frequency occurred among children under 2 years of age (60.7%). In 68.7% of cases feces were liquid and in 37.5% mucus, pus or blood was present in stools. Persistent diarrhea was more frequent among malnourished patients (p less than 0.001) who, in turn, suffered the greatest nutritional deterioration in relation to the episode of diarrhea. Intravenous fluids were required by 23.3% of patients while 27.9% were admitted to hospital. This contrasts with patients who suffer episodes which lasted less than 15 days, who were all orally hydrated and only 7.8% required hospitalization (p less than 0.01).

Faecal excretion of rotavirus and other enteropathogens in newborns of the high and low socio-economic stratum in Santiago, Chile

Faecal excretion of enteropathogens was studied in newborns in their first week of life. Rotavirus was investigated in 225 neonates, of whom 107 belonged to the low socio-economic stratum (SES) and 118 to the high SES. Half of each group were delivered by caesarean section. Rotavirus was detected in 10 infants (4.4%). Eight of them had been in the same ward and excreted the same viral electrophoretype. Enteropathogenic bacteria were isolated from 8 out of 57 (14.0%) newborns. Positive cultures were equally distributed by SES and route of delivery. Giardia lamblia was the only parasite detected, in one infant (2.6%) of the high SES. None of the children developed symptoms. Faecal excretion of enteropathogens ended spontaneously within a week in all cases. It is suggested that the lack of symptomatology and the spontaneous termination of the faecal excretion are related to immaturity of the small intestinal mucosa, that does not allow the completion of the steps that must take place during a successful infectious event.

Effect of structured dietary fiber on bioavailability of amoxicillin

The effect of structured dietary fiber on the bioavailability of amoxicillin (AMX) was evaluated. Ten healthy volunteers ingested one of two isocaloric, isonitrogenous diets providing 7.8 gm/day (diet I) and 36.2 gm/day (diet II) of structured fiber for 3 days. Then they ingested one tablet (500 mg) AMX after breakfast. The other diet was administered for an additional 3 days and the study was repeated. Plasma and urinary AMX concentrations were measured at 9 and 24 hours, respectively, by a microbiologic technique. An open one-compartment model was used for pharmacokinetic analysis. AMX was absorbed more slowly when ingested with diet I than with diet II: the absorption rate constant was 1.04 +/- 0.37 and 1.75 +/- 0.75 (P less than 0.05); lag time for absorption was 0.34 +/- 0.13 hours and 0.29 +/- 0.11 hours (P less than 0.05). The first-order rate constant and elimination half-life were similar. Bioavailability was higher with diet I: the AUC was 12.17 +/- 3.04 vs. 9.65 +/- 2.64 micrograms/ml/hr with diet II (P less than 0.05). A higher content of dietary fiber increased AMX absorption rate and decreased the amount of drug absorbed.

Chronic environmental enteropathy in a temperate climate

Forty-three apparently healthy young adult male volunteers underwent an evaluation of their nutritional status, blood chemistry and faecal excretion of enteropathogens, which did not reveal current malnutrition or illnesses. Ten of them were further studied for small intestinal histology, culture of aerobic and anaerobic bacteria in the duodenal juice, disaccharidase activities, glucose absorption and faecal excretion of fat and nitrogen. The study revealed mild morphological changes associated with the appearance of anaerobic bacteria in the upper intestine, decreased glucose transport and increased faecal losses of nitrogen. Although all these changes were rather mild, they may be significant for people whose diet is of borderline nutritional quality.

Acute diarrhoea and asymptomatic infection in Chilean preschoolers of low and high socio-economic strata

Preschoolers who belonged to the high (Group I, n = 112) or the low (Group II, n = 90) socio-economic stratum were followed prospectively for six months. Mean monthly incidence of diarrhoea was 3 and 7 episodes per 100 children for Group I and Group II respectively (p less than 0.001). Episodes were shorter and affected a smaller proportion of children in Group I (p less than 0.002 and p less than 0.05), respectively). Bacterial enteropathogens were recovered in 12.6% and 13.5% of the episodes in Group I and Group II and parasites in 15.4% and 62.8%, respectively. Rotavirus was detected once in each group. Asymptomatic carrier rates for enteropathogenic bacteria were 12.0% in Group I and 7.2% in Group II. The corresponding figures for parasites were 28.2% and 62.8% (p less than 0.001). Nutritional status was normal in all children. These results suggest that socio-economic stratum plays an important role in the characteristics of diarrhoeal illness in the groups which conform the population of the less developed countries. Acute diarrhoea is less frequent in preschoolers living in Santiago than in other developing areas. Rates of asymptomatic infection are high.

Enteropathogens associated with acute diarrhea in hospitalized infants

Thirty-five infants of low socioeconomic status who were living in urban Santiago were hospitalized for acute diarrhea were prospectively evaluated for the presence of enteropathogens associated with the episode. Some degree of malnutrition was evident in 20 infants (57.1%); 15 of these (75%) were under 6 months of age. Mean duration of the hospital stay was 11.8 days for well-nourished patients and 15.7 days for the malnourished patients. One or more enteropathogens were found in 60% of the cases studied: in 17 cases (48.6%) these were bacteria and in four cases (11.4%) it was rotavirus. Parasites were not detected. In three patients, two different pathogens were demonstrated. Among the bacteria, 12 isolates (34.3%) were enteropathogenic E. coli (EPEC) and two (5.7%) were Shigella. Campylobacter jejuni was also isolated from two different cases (5.7%) and Salmonella from one case (2.9%). The recovery of pathogens was independent of the nutritional status. Mean age of detection of EPEC was 3.2 months among well-nourished infants and 6.2 months among the malnourished (p less than 0.001). Half of the EPEC strains isolated were multiresistant to antibiotics. One of these strains transferred some of its resistance in vitro to E. coli K12. Ampicillin and kanamycin were the antibiotics to which EPEC showed the greatest resistance. The other bacterial pathogens were mostly sensitive to antibiotics. Campylobacter jejuni, together with Shigella, was the second most frequent pathogen isolated during episodes of diarrhea. Campylobacter should be included in the routine study of diarrheal episodes in our setting.

Acute diarrhoeal disease in children under 7 years of age in a peri-urban slum of Santiago, Chile

A group of 168 families who lived in a peri-urban slum in Santiago were surveyed for 9 months. All of them had a child under 7 years of age. Medical activities and data collection were carried out at a Field Station and by means of twice-weekly visits to each home, at which time cases of diarrhoea were recorded and investigated. Faecal samples for bacteriological, parasitological and rotavirus studies were obtained during each episode. The characteristics of clinical course, hygienic practices in the family, and monthly anthropometric measurements of infants and toddlers were also recorded. The mean monthly incidence of diarrhoea was 7.1 episodes per 100 children. Of the episodes, 44.2% were associated with pathogenic bacteria, 14.4% with rotavirus, 38.4% with parasites and in 27.9% no enteropathogens were identified. It was found that adequate hygienic habits were not associated with a decreased risk of developing diarrhoea and that about 60% of children did not have diarrhoea throughout the study period. The nutritional status was adequate in most cases: weight-for-age was below the 5th percentile in 11.5% of subjects and the height-for-age was normal in all. No moderate or severe cases of malnutrition were detected.