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Biomedical subjects

C F Lanata

Publications and source records attributed to C F Lanata.

At least 37 records · Page 2Linked to original sources
PubMed1996

Effect of postpartum maternal infection on proteins and trace elements in colostrum and early milk.

In developing countries, maternal infections during lactation are common. In this study, we evaluated the effect of acute maternal postpartum infection on the composition of colostrum and early milk with special emphasis on milk proteins and trace elements. The study was carried out in two maternity hospitals in Lima, Peru. Subjects were normally nourished women (body mass index (BMI) > 20.0) who intended to exclusively breastfeed their child and who had fever and clinical symptoms of infection within the first 48 h postpartum (n = 34). Non-ill women of similar characteristics were selected as controls (n = 23). Blood and milk samples were taken on days 1 and 14 postpartum. An acute phase response was confirmed by significantly increased serum levels of C-reactive protein in infected women. Serum zinc levels increased significantly from day 1 to day 14, but were not affected by infection. Serum copper levels were significantly higher in ill women than in non-ill women on day 1. All participating women were breastfeeding on day 14. Whey protein levels, the whey/casein ratio and total protein levels decreased significantly with time, but were not affected by infection. There were no differences in milk iron or copper levels with time or infection. Milk zinc levels decreased significantly with time, but were not affected by infection. Maternal infection during the early postpartum period does not appear to adversely affect the initiation of lactation or milk protein and trace element contents.

Adolescent↗
PubMed1994

Diarrhoea--defining the episode.

BACKGROUND: There is still no consensus on the appropriate definition of an 'episode' of diarrhoea, even though it has been shown that the choice of definition has a major impact on reported incidence rates. Previous work has focused on the observed distribution of illness episodes in time but has not attempted to determine whether the patterns observed depart from those expected by chance. METHODS: A simple theoretical model of the distribution of illness episodes is developed, based on the concept of a 'trigger event'. The model incorporates elements relating to the duration of symptoms, inter-individual variation in incidence rates and seasonality. Appropriate parameters for the model are derived from two empirical datasets. RESULTS: It is shown that short intervals between one aetiologically distinct period of diarrhoea and the next will frequently occur by chance, especially in circumstances where high incidence rates and within-child clustering of illness prevail. The duration of symptoms will have no effect on the length of intervals between periods of illness, and seasonality is unlikely to have a major impact. Over 10% of all non-initial trigger events might be expected to occur during the course of a pre-existing period of diarrhoea, and would not therefore be identified in a study based on reported symptoms. CONCLUSIONS: The findings of previous studies, suggesting that 2 or 3 days without symptoms will generally mark a new episode of diarrhoea, are endorsed. Modelling the expected distribution of illness in time may help to highlight structural or analytical problems with empirical datasets.

Child↗
PubMed1994

Validity of a respiratory questionnaire to identify pneumonia in children in Lima, Peru.

We conducted a nested case-control study utilizing cases of clinical pneumonia identified in a community-based prospective surveillance study of children under 3 years of age in order to test the validity of a survey questionnaire. Three types of sex- and age-matched concurrent controls were selected from the surveillance population: acute respiratory infection (ARI) clinic controls. ARI community controls and healthy community controls. Survey interviews were scheduled at random for any of four consecutive 7-day periods after the diagnosis of the case. The questionnaire covered a 30-day recall period. The combination of cough with fast breathing or shortness of breath, and with fever, provided the highest positive predictive value for pneumonia. The sensitivity of some questions dropped when the interview took place more than 15 days after the diagnosis of the case. However, the utilization of a 15-day recall period did not increase the positive predictive value of the survey. We conclude that in this trained population under surveillance, a survey questionnaire utilizing a 30-day recall period and using the combination of cough, fast breathing or shortness of breath and fever to define episodes with a high likelihood of pneumonia, offers an acceptable tool for the monitoring and evaluation of respiratory control programmes. This questionnaire needs further evaluation in an untrained population and in other regions before it can be adopted for use in ARI control programmes.

Bias↗
PubMed1994

Observations on handwashing and defecation practices in a shanty town of Lima, Peru.

Following a two-year cohort study of diarrhoeal diseases in children aged 0-35 months from a shanty town in Lima, 62 families were chosen for detailed observation of hygiene practices. All handwashing and defecation episodes which occurred during a 10-hour observation period (8am-6pm) were recorded. The youngest child in each family was selected as the index child for observation. Handwashing was seen on 483 occasions with 71% of the index children and 80% of mothers observed at least once. The use of clean water, soap and the thoroughness of the handwashing varied according to the purpose, with "better" behaviour observed more frequently when the person was preparing to go out. Forty-five index children (72%) were observed to defecate at least once. Infants defecated in their diapers or clothes; toddlers defecated more indiscriminately around the home area. Handwashing after defecation was rare (11% of occasions) and usually without soap. Faeces were often left accessible to children and animals (42% of occasions), especially when defecation occurred around the home/yard, and the data suggested this occurred more frequently in "higher" diarrhoea households. Stools deposited on the floor were usually just swept aside, covered with earth or eaten by dogs. Those deposited outside the home were frequently left untouched during the observation period or similarly cleared. Soiled clothes were usually left or washed separately, and stools in potties were thrown in latrines. These results suggest hygiene interventions might focus on clearance of stools from home surroundings, increased utilisation of potties and separate washing of soiled clothes.

Child, Preschool↗
PubMed1993

Potential magnitude of the misclassification of a population's trace element status due to infection: example from a survey of young Peruvian children.

To examine the effects of concurrent infection on population-based assessment of trace element status, we collected data on clinical signs and laboratory indicators of infection when obtaining blood for serum zinc, copper, and ferritin analyses in 153 Peruvian children aged 11-19 mo. Fifty-two (34.7%) of the children had some reported sign of infection and 43 (28.3%) had elevated C-reactive protein concentrations or leukocytosis. Children with any evidence of infection had marginally lower mean (+/- SD) serum zinc concentrations (7.0 +/- 2.3 vs 7.5 +/- 2.0 mumol/L, P = 0.16) and significantly greater serum copper (24.7 +/- 4.7 vs 22.7 +/- 4.2 mumol/L, P = 0.006) and serum ferritin concentrations (10.0 +/- 12.9 vs 3.9 +/- 4.4 micrograms/L, P < 0.001) than did those without infections. Infection caused an underestimation in the rate of low copper status by 1 percentage point and low iron status by 12 percentage points. Thus, the effect of concurrent infections is of variable magnitude and may differ by nutrient, nutritional status of the population, and prevalence and severity of infections.

C-Reactive Protein↗
PubMed1993

Safety, immunogenicity, and excretion pattern of single-dose live oral cholera vaccine CVD 103-HgR in Peruvian adults of high and low socioeconomic levels.

Groups of 122 Peruvian adults of low socioeconomic level (SEL) and 125 of high SEL received a randomly allocated 5 x 10(9)- or 5 x 10(8)-CFU dose of CVD 103-HgR live oral cholera vaccine or a placebo. The vaccine was well tolerated. Vibriocidal seroconversions occurred in 78% of high-SEL and 72% of low-SEL subjects who ingested the high dose and in 78 and 49%, respectively, of those who received the low dose.

Administration, Oral↗
PubMed1993

HIV, breast-feeding and under-5 mortality: modelling the impact of policy decisions for or against breast-feeding.

A computer model was developed to assess the impact on under-5 child mortality of breast-feeding practices in developing countries in the context of HIV infection. The model was used to estimate the effect on mortality of cessation of breast-feeding among mothers HIV-positive and mothers HIV-negative at birth, for both urban and rural settings. Using parameter values for a hypothetical East African country, cessation of breast-feeding in urban areas was predicted to result in increases in under-5 mortality of 108% for children of mothers HIV-negative at birth, and 27% for those HIV-positive at birth, with slightly larger increases in rural areas, suggesting that breast-feeding should continue to be promoted. A sensitivity analysis was conducted to identify critical values of key variables for which a review of policies encouraging breast-feeding is indicated. This showed that, even under extreme assumptions, cessation of breast-feeding among mothers HIV-negative at birth (but at risk of acquiring HIV during the lactation period) would increase under-5 mortality. For mothers HIV-positive at birth, the key variables are the additional risk of vertical transmission attributable to breast-feeding, the under-5 mortality rate (U5MR) in breast-fed children, and the relative risk of mortality in non-breast-fed compared to breast-fed children. Depending on the values of these key variables, there may be some urban populations with low U5MR in which the positive and negative effects on under-5 mortality of a policy change are finely balanced. However, no change in policy should be made in these areas until more precise information is available on the key variables, and the many adverse consequences of such a change have been fully explored.

Breast Feeding↗
PubMed1992

Etiologic agents in acute vs persistent diarrhea in children under three years of age in peri-urban Lima, Perú.

In a longitudinal study of acute and persistent diarrhea in 677 children less than three years old in a peri-urban community of Lima, Perú, during 27 months of surveillance, stools were cultured at the beginning of each diarrheal episode and on each subsequent week of illness. Analyzing stool cultures only from children who had not received antibiotic treatment in the 48 h prior to the culture, no association was found between any enteropathogen and persistent diarrhea. We did not find any increase in mixed infections in persistent diarrhea episodes as compared with acute diarrhea, controlling for age, season and anthropometric status. The isolation rate for any given enteropathogen was similar during the first, second, third or later week of illness, but when the presence of a specific enteropathogen was sought in sequential stools within a single episode, no evidence of persistent infection was found. This study shows that in developing countries with a high incidence of diarrheal diseases frequent re-infections with enteropathogens prevalent in the population are one reason for prolonged illnesses. Host factors that increase susceptibility to infection or decrease recovery from illness may also play a role. Further studies of these factors, such as micronutrient deficiencies, are needed to identify a public health intervention to control persistent diarrhea, a condition associated with mortality in many developing countries.

Acute Disease↗
PubMed1992

Feeding during acute diarrhea as a risk factor for persistent diarrhea.

Dietary intake during diarrhea in children less than three years of age was estimated from information recorded on illustrated dietary forms used by children's caretakers during the first week of illness in a prospective community-based study of diarrheal diseases in Lima, Peru. The frequency of consumption and the amount consumed of food groups and selected commonly consumed foods were analyzed by the final duration of the diarrheal episode. Cereals were less frequently consumed during the acute phase of diarrheal episodes that ultimately became persistent (> 14 days' duration), apparently shortening the duration of the episode by one day (median duration of four days in children not consuming vs three days in children consuming cereals during diarrhea, p < 0.02 Kaplan-Meier log-rank test). Only roots and tubers (mainly potatoes) were consumed in greater quantity during episodes that became persistent. There was no evidence that consumption of breast milk or non-maternal milk was associated with an alteration in diarrheal duration. This study provides further evidence of the beneficial effects of continuing feeding during diarrhea using foods available at the home level, especially cereals, which are commonly used in the diet of young children.

Acute Disease↗
PubMed1991

Epidemiologic, clinical, and laboratory characteristics of acute vs. persistent diarrhea in periurban Lima, Peru.

Longitudinal studies of acute and persistent diarrhea in 677 children less than 3 years old were conducted for 27 months in an underprivileged, periurban community near Lima, Peru. Incidence rates and accurate durations of diarrhea were obtained by twice-weekly community-based surveillance and clinical and laboratory features of diarrheal episodes were documented. Study children had an overall incidence of diarrhea of 8.1 episodes per child-year and an incidence of persistent (greater than 14 days) diarrhea of 0.25 episodes per child-year. Episodes of longer duration were associated with young age (0-5 months) and more severe illness (greater than or equal to 6 diarrheal stools per day) in the first week. None of the laboratory tests performed in the first week of illness (fecal leukocytes, blood, reducing substances, pH, or fat) proved of value to identify episodes that would become persistent. Although steatorrhea was commonly present in the acute phase of the illness, it became less frequent by the third or subsequent week of illness in the persistent diarrheas. These results suggest that there are no clinical or laboratory features of acute diarrhea that are strongly predictive of the subset of diarrheas that persist. Thus, it is important that all diarrheal episodes should have appropriate fluid and dietary management and follow-up to detect the persistent diarrheas that may need special intervention.

Acute Disease↗
PubMed1991

Transmission factors and socioeconomic status as determinants of diarrhoeal incidence in Lima, Peru.

As part of a longitudinal, community-based study of diarrhoeal morbidity in a peri-urban community in Lima, Peru, a household survey was administered to ascertain possible risk factors, based on transmission routes, for diarrhoeal incidence. Socioeconomic information was also obtained in the survey and a composite socioeconomic status (SES) indicator was created based on four variables: income (wealth), ownership of 4 functioning electrical household appliances, community participation, and house construction. Both transmission factors and the SES indicator were analysed for their effects on diarrhoeal incidence using both bivariate and multivariate methods. The SES indicator, method of water storage, if the child was seen eating faeces or soil were all significantly associated with diarrhoeal incidence. In a final logistic model, water storage, location of defecation for children, child eating soil or faeces, and age, demonstrated significant results. Children in households with water stored in containers without a faucet were twice as likely to have a high incidence of diarrhoea (greater than 7 episodes/child/year). The SES indicator was not significant in the logistic model, but high SES was associated with whether or not the child was reported as having been seen eating faeces or soil and with non-use of latrines by adults. Also low SES households were more likely to have better water storage methods. Therefore, it would seem that (SES) does not independently determine diarrhoeal incidence, but rather may be functioning through these transmission factors to affect diarrhoeal incidence.

Child, Preschool↗
PubMed1991

Lot quality assurance sampling techniques in health surveys in developing countries: advantages and current constraints.

Traditional survey methods, which are generally costly and time-consuming, usually provide information at the regional or national level only. The utilization of lot quality assurance sampling (LQAS) methodology, developed in industry for quality control, makes it possible to use small sample sizes when conducting surveys in small geographical or population-based areas (lots). This article describes the practical use of LQAS for conducting health surveys to monitor health programmes in developing countries. Following a brief description of the method, the article explains how to build a sample frame and conduct the sampling to apply LQAS under field conditions. A detailed description of the procedure for selecting a sampling unit to monitor the health programme and a sample size is given. The sampling schemes utilizing LQAS applicable to health surveys, such as simple- and double-sampling schemes, are discussed. The interpretation of the survey results and the planning of subsequent rounds of LQAS surveys are also discussed. When describing the applicability of LQAS in health surveys in developing countries, the article considers current limitations for its use by health planners in charge of health programmes, and suggests ways to overcome these limitations through future research. It is hoped that with increasing attention being given to industrial sampling plans in general, and LQAS in particular, their utilization to monitor health programmes will provide health planners in developing countries with powerful techniques to help them achieve their health programme targets.

Developing Countries↗
PubMed1990

An evaluation of lot quality assurance sampling to monitor and improve immunization coverage.

Quality assurance sampling techniques with small samples offer a method of monitoring performance of health services in small health areas, and of identifying areas with poor performance in which remedial actions need to be targetted. Lot Quality Assurance Sampling methods were used to assess the coverage resulting from three immunization campaigns in rural and urban areas in the mountains of Peru. Application of these methods in 12 health areas with populations of 538 to 15 780 by Ministry of Health personnel proved feasible and could be used to identify areas with poorer vaccination coverage. Further discussion about possible reasons for poor coverage led to corrective actions in these health areas and an improvement in overall coverage from 78% to 88% in a three-month period. These quality assurance methods are a useful supervisory tool to improve health programme performance.

Child, Preschool↗
PubMed1990

Detection of Salmonella typhi carriers in food handlers by Vi serology in Lima, Peru.

The work described here sought to assess the merits of using an indirect hemagglutination test employing highly purified Vi antigen to screen a high-risk population for chronic S. typhi carriers in Lima, Peru. A total of 1,931 female food handlers over 30 years old were enrolled in the study. Indirect hemagglutination tests performed on these subjects' sera, taking a titer of 1:40 or more as positive, yielded 29 positive results. Subsequent bacteriologic testing performed on 26 of these 29 subjects identified four (15%) as S. typhi carriers. The procedure had a sensitivity of 79%, indicating that the prevalence of S. typhi carriers among the population studied was on the order of 262 per 100,000. It appears that Vi serology employing highly purified Vi antigen offers a practical and cost-effective way of screening for S. typhi carriers in both endemic and nonendemic typhoid fever areas.

Antigens, Bacterial↗
PubMed1989

Protection of Peruvian children against rotavirus diarrhea of specific serotypes by one, two, or three doses of the RIT 4237 attenuated bovine rotavirus vaccine.

A randomized placebo-controlled double-blind field trial of RIT 4237 attenuated rotavirus vaccine in Lima, Peru, evaluated the protection against diarrheal illness by one, two, or three doses of vaccine. There were 391 children, 2-18 months old, studied for the occurrence of diarrhea during the 18 months after vaccination. Three doses of the vaccine provided 40% protection against any diarrheal illness associated with rotavirus alone but 58%-75%; protection against the more severe rotaviral illnesses. The vaccine appeared to be more efficacious when it was administered to children in the first year of life. Three doses provided up to 89% efficacy against more severe diseases due to serotype 1 rotavirus, and one dose also afforded significant protection. The protection was lower, even with three doses, against serotype 2 rotavirus. This vaccine trial has provided important insights on how such trials should be conducted and on the serotype-specificity of protection from rotavirus infection. Future vaccines should be able to protect against severe disease caused by all rotavirus serotypes and must work in developing countries where rotavirus is the most important cause of diarrheal mortality.

Antibodies, Viral↗
PubMed1989

Delayed cutaneous hypersensitivity: epidemiologic factors affecting and usefulness in predicting diarrheal incidence in young Peruvian children.

Cell-mediated immunity, as assessed by delayed cutaneous hypersensitivity, can be diminished by malnutrition and viral infections. In turn, decreased immune functioning might lead to more frequent or more severe infectious diseases. Delayed cutaneous hypersensitivity was assessed in young Peruvian children by simultaneous application of seven standardized antigens and a negative control (Multitest CMI). Response to tuberculin was frequent and was higher in children vaccinated with Bacillus Calmette-Guérin, response to tetanus or diphtheria toxoids was also good, especially in children who had received at least two doses of diphtheria-tetanus toxoids-pertussis vaccine. Two summary assessments, the number of positive responses and the sum of indurations of all positive responses provided useful measures of delayed cutaneous hypersensitivity. Responsiveness, as assessed by these summary measures, was inversely related to the incidence of diarrhea, identified by household surveillance for the 6 months after the skin test. Undernutrition, as assessed by weight for age or length for age, was also a significant determinant of the incidence of diarrhea, but not the duration of episodes, in this group of study children. Depressed cell-mediated immunity and malnutrition may be important risk factors for diarrhea in developing country children.

Anthropometry↗