Persistent diarrhoea in a rural area of Bangladesh: a community-based longitudinal study

As part of a health impact evaluation of a water supply and sanitation project in a rural area of Bangladesh, diarrhoeal morbidity was recorded in children 0-4 years of age using weekly recall in household interviews, during the period March 1984 to December 1987. During the baseline year, 1984, the incidence rate of all diarrhoea episodes (3.8 episodes per child per year), and those defined as persistent, duration greater than 14 days (0.6 episodes per child per year), showed a similar age distribution, peaking in the 12-23 month age group. Sixteen per cent of all episodes were classified as persistent, and this proportion was greatest in the 0-5 month age group (25%). Children suffering at least one episode of persistent diarrhoea in 1984 also experienced a higher incidence of acute diarrhoea (less than = 14 days duration) than those suffering acute diarrhoea only (4.2 versus 3.7 episodes per child per year). Persistent diarrhoea showed a similar seasonal pattern to that of all episodes. Rates of abdominal pain, isolation of Shigella spp and a diagnosis of dysentery were significantly higher in persistent episodes than in acute episodes. Closer follow-up of children during 1986 and 1987, through the recording of all periods of absence of the child from the home, showed that overall diarrhoea incidence rates were little affected when absence was taken into account, but that the incidence of persistent diarrhoea and the proportion of episodes classified as persistent were significantly reduced. The implications of this methodological problem are discussed.     

An epidemiological study of rotavirus diarrhoea in a cohort of Nigerian infants: II. Incidence of diarrhoea in the first two years of life

In a community-based prospective study of diarrhoeal diseases carried out in Ibadan, 131 infants were selected at birth. The maximum possible length of follow-up ranged from 16 to 24 months. Weekly surveillance for diarrhoea was carried out at home by Primary Health Care workers. Each child was also required to attend a monthly clinic. Of the 131 babies, 95 (73%) completed at least one year of follow-up. All of these had at least one episode of diarrhoea within the first year of life. The incidence rate of diarrhoea in the first year of life was 3.2 cases/child/year. The mean duration of diarrhoea days in the first year of life was 16 per child per year (range 3-34 days). The peak incidence of diarrhoea and the greatest number of diarrhoea days were in the age interval 6-9 months. The mean duration of diarrhoea was five days per episode. Faecal samples for 280 diarrhoea episodes during the first year of life were examined for rotavirus using the ELISA technique: 22 (7.7%) were found to be positive. The mean duration of rotavirus diarrhoea episodes was eight days.     

Impact of zinc supplementation on subsequent growth and morbidity in Bangladeshi children with acute diarrhoea.

OBJECTIVE: To assess the impact of zinc supplementation during acute diarrhoea on subsequent growth and morbidity in malnourished young children. DESIGN: Double blind randomized controlled clinical trial SETTING: International Centre for Diarrhoeal Disease Research, Bangladesh. SUBJECTS: Sixty-five children aged 3-24 months with acute diarrhoea for less than 3 d. INTERVENTION: Either elemental zinc (20 mg/d) in a multivitamin syrup or multivitamin syrup alone divided in three divided daily doses for a period of two weeks. Children were followed up weekly at home to assess subsequent growth and morbidity for a period of eight weeks. MAIN OUTCOME MEASURES: Gain in length and body weight and reduction in diarrhoea and respiratory tract infection. RESULTS: During the follow-up, zinc supplemented children showed significantly greater cumulative length gain (18.9 mm vs 14.5 mm, P <0.03) and comparable body weight gain than the children of the control group. Subsequent length gain was not correlated with initial height in the zinc-supplemented group (r=-0.13), P = 0.5), but was significantly correlated in the control group (r = -0.6, P < 0.0007). Zinc-supplemented and stunted children (< or = 90% length for age n = 18) experienced significantly fewer episodes of diarrhoea (0.07 vs 0.6, P < 0.05) and respiratory illness (1.0 vs 2.4, P < 0.01) compared to the control group. The underweight children (< or = 71% weight/age n = 38) receiving zinc-supplementation also had fewer episodes of diarrhoea (0.4 vs 1.0, P<0.04) and shorter duration of diarrhoeal episodes (1.0 vs 3.0d, P<0.04) compared to their counterparts in the control group. CONCLUSION: These results suggest that a short course of zinc supplementation to malnourished children during acute diarrhoea reduces growth-faltering and diarrhoeal and respiratory morbidity during subsequent two months.     

Growth and diarrhoeal disease surveillance in a rural Ghanaian pre-school child population

This paper is a report of the first year of follow-up on 250 pre-school children in a village in Ghana. The mean weight for age and the mean height for age at the start of the study, ranged between 81 and 97% and 91 and 101.4% of the median WHO reference standards respectively. Classified according to Waterlow (1973) 59.6% of the children were normal, 27.2% were thin, 8.9% were stunted, 3.4% were wasted and 0.9% were stunted and wasted. The mean velocity of height gain was 26.8 cm/year at birth; 9.6 cm/year at age of six months and thereafter the rate decreased almost linearly to a rate of 5 cm/year at the age of 60 months. The curve for weight velocity had a similar shape to that of the height. The rate was on the average 5 kg/year at birth, and 1.7 kg/year at age of six months. Children over 30 months of age gained approximately, 0.5 kg/year compared to an expected gain of about 2 kg/year. The mean incidence of diarrhoeal diseases was 1.9 episodes per child per year. 34.4% of the cohort did not report on any episode of diarrhoea over the one year period. Highest incidence occurred in children between the ages of 7 and 12 months. Children who were less than 80% of the standard weight for age at the start of the study had significantly more diarrhoeal episodes than the rest. The mean incidence of diarrhoeal diseases per year increased as both height for age and weight for height decreased. It is suggested that primary intervention against diarrhoeal morbidity might be better aimed at improving childhood nutrition.     

Epidemiology and predictors of infant morbidity in rural Malawi

In rural Malawi, 703 newborns were visited monthly for 1 year to describe the epidemiology and health-seeking behaviour during acute episodes of diarrhoea, respiratory infections (ARI) and malaria. On average, the infants suffered from 1.3 annual episodes (11.0 illness days) of diarrhoea, 1.1 episodes (9.4 days) of ARI and 0.7 episodes (4.8 days) of malaria. Multivariate analysis with polychotomous logistic regression indicated that the amount of morbidity was associated with the child's area of residence, weight in early life, number of siblings, father's marital status and the source of drinking water. Diarrhoea and malaria were most common at 6-12 months of age and during the rainy months whereas respiratory infections peaked at 1-3 months of age and in the cold season. Ten per cent of diarrhoea, 9% of ARI and 7% of malaria episodes lasted for more than 14 days. Fifty-eight infants died, giving case fatality rates of 1% for diarrhoea, 2% for ARI and 4% for malaria. One-third (37%) of the illness episodes were managed at home without external advice. A traditional healer was consulted in 16% of episodes and a medical professional in 55% of episodes. If consulted, traditional healers were seen earlier than medical professionals (median duration after the onset of symptoms 0.7 vs. 1.8 days, P < 0.001). Traditional healers were significantly more commonly used by those families whose infants died than by those whose infants did not die (odds ratio 1.8, 95% CI 1.1, 3.0). Our results emphasise the influence of seasonality, care and living conditions on the morbidity of infants in rural Malawi. Case fatality for diarrhoea, ARI and malaria was high and associated with health-seeking behaviour among the guardians. Future interventions must aim at early and appropriate management of common childhood illnesses during infancy.     

A community-based study of respiratory episodes in Melbourne, Australia

OBJECTIVE: To provide recent data regarding the epidemiology of community-based respiratory infections in Australia. METHODS: A longitudinal study between 1997-99 involving collection of a health diary from 600 families in Melbourne. RESULTS: More than 80% of study participants reported at least one respiratory episode over 15 months. An average of 2.2 respiratory episodes per person per year was reported, with a mean episode duration of 6.3 days. On average, subjects were symptomatic for 4.2% of the study days. Compared with other age groups, children aged less than two years were most likely to have at least one respiratory episode, a greater number of episodes per person and the longest episode duration (6.8 days). Approximately, one in three (28.7%) respiratory episodes were associated with a doctor's visit, and one in four (23%) necessitated time off school or work. Exposure to other people with respiratory symptoms was commonly reported. CONCLUSIONS: Respiratory infections are common, cause a significant amount of morbidity, and are major contributors to the total community health burden. IMPLICATIONS: The direct and indirect costs of respiratory infections to the community are substantial.     

Incidence and risk factors for diarrhoea and acute respiratory infections in urban communities of Pernambuco, Brazil

Magnitude and distribution of Diarrhoea and Acute Respiratory Infections (ARI) in children were studied within a larger broader research that focused on health education. Two household surveys were conducted in a sample of families with at least one child under five years of Recife and Olinda in April-May 1992 and 1994. The total number of children studied was 5,436. The estimated adjusted annual incidence rate (AAIR) of diarrhoea was 2.7 episodes per child. The two-week incidence rate of diarrhoea was 10.2% for both years. Risk factors associated with higher incidence of diarrhoea were age (under two years), lack of sanitation facilities, and absence of electrical appliances in the household. Estimated AAIR of ARI was 9. 5 episodes per child. The two-week incidence rate of ARI was 41.0% in 1992 and 32.6% in 1994. Majority of ARIs affected the upper respiratory tract (75.9%). The only factor consistently associated with a higher risk of ARI was age (under three years). Study results indicate that both pathologies are still an important health problem for children under five in Pernambuco. In particular, in the case of diarrhoea the need for improving the access to basic services, such as water supply and sewage system is urgently needed.     

The effect of probiotics on respiratory infections and gastrointestinal symptoms during training in marathon runners

Heavy exercise is associated with an increased risk of upper respiratory tract infections. Strenuous exercise also causes gastrointestinal (GI) symptoms. In previous studies probiotics have reduced respiratory tract infections and GI symptoms in general populations including children, adults, and the elderly. These questions have not been studied in athletes before. The purpose of this study was to investigate the effect of probiotics on the number of healthy days, respiratory infections, and GI-symptom episodes in marathon runners in the summer. Marathon runners (N = 141) were recruited for a randomized, double-blind intervention study during which they received Lactobacillus rhamnosus GG (LGG) or placebo for a 3-mo training period. At the end of the training period the subjects took part in a marathon race, after which they were followed up for 2 wk. The mean number of healthy days was 79.0 in the LGG group and 73.4 in the placebo group (P = 0.82). There were no differences in the number of respiratory infections or GI-symptom episodes. The duration of GI-symptom episodes in the LGG group was 2.9 vs. 4.3 d in the placebo group during the training period (P = 0.35) and 1.0 vs. 2.3 d, respectively, during the 2 wk after the marathon (P = 0.046). LGG had no effect on the incidence of respiratory infections or GI-symptom episodes in marathon runners, but it seemed to shorten the duration of GI-symptom episodes.     

Acute respiratory infections in children: a community based longitudinal study in south India

A community based longitudinal study was conducted in Malpe, a coastal village of Udupi district, Karnataka state, to investigate acute respiratory infections (ARI) in children. A cohort of 91 children under 3 years of age were followed up for 1 year, leading to 2047 fortnightly observation. On an average every child had 11.3 months of follow up. The overall incidence of ARI was 6.42 episodes per child per year. On an average each episode lasted for 5.06 days. Mean duration of ARI during one year was 32.5 days per child. Most of the ARI episodes in children (91.3%) were of simple Cough & Cold (no pneumonia). However, 8.2% developed pneumonia and only 0.51% had severe pneumonia. Incidence of ARI was almost same in male and female children. There was no significant difference in incidence among various age groups. But the incidence of pneumonia was significantly higher among infants (p<0.00002). Children of poor housing with smoke producing conditions suffered more frequently (p,002).     

Effect of vitamin A supplementation on diarrhoea and acute respiratory tract infection in children

To determine the effect of a massive single oral dose of Vitamin A (200,000 IU) supplementation on diarrhoea and acute respiratory infection (ARI), a double blind placebo controlled trial involving 174 children under six years of age (excluding infants) was carried out in a Calcutta slum community. Ninety-one children received vitamin A supplementation (experimental group) and 83 children received a placebo (control group). All the children were followed up for six months by active fortnightly surveillance for occurrence of diarrhoea or ARI and their duration. There was no statistically significant difference in the incidence of diarrhoeal episodes or ARI. However, there was a significant difference (p<0.05) in the average duration of diarrhoea per episode (2.1 vs. 3 days) between the experimental and control groups. Possible beneficial effects of a single oral dose of vitamin A supplementation on the incidence of diarrhoea and ARI could not be demonstrated in the present study.     

Population-based study of acute respiratory infections in children,Greenland

Acute respiratory infections (ARI) are frequent in Inuit children, in terms of incidence and severity. A cohort of 294 children <2 years of age was formed in Sisimiut, a community on the west coast of Greenland, and followed from 1996 to 1998. Data on ARI were collected during weekly visits at home and child-care centers; visits to the community health center were also recorded. The cohort had respiratory symptoms on 41.6% and fever on 4.9% of surveyed days. The incidence of upper and lower respiratory tract infections was 1.6 episodes and 0.9 episodes per 100 days at risk, respectively. Up to 65% of the episodes of ARI caused activity restriction; 40% led to contact with the health center. Compared with studies from other parts of the world, the incidence of ARI appears to be high in Inuit children.     

The influence of illnesses on the food intake of young children

The effect of illness on the food intake of 125 preschool children in a residential home was studied. The children had a mean of 6.8 episodes of illness per child per year. Upper respiratory infections, diarrhoeas and fevers depressed food intake by 15-20%. Measles resulted in prolonged and profound depression of appetite, and caused weight losses in the affected children. The number of days of depressed appetite due to illness had a cumulative effect on growth; poor increases in height and weight were seen in these children who had many days of reduced appetite due to illness. Measles vaccination is strongly recommended for improved growth and nutritional status of preschool children.     

Natural history of Giardia infection of infants and children in rural Guatemala and its impact on physical growth

Longitudinal data on Giardia excretion, diarrheal disease, and physical growth during the first 3 yr of life collected more than 20 yr ago in 45 Guatemalan children were analyzed. This report describes the natural history of this infection and estimates its effects on growth. All children had at least one Giardia infection, prevalence and incidence rates reaching 20.2% and 5.3%, respectively by the end of the third year. The mean number of Giardia infections per child increased from 0.7 in the first to 3.6 in the third year. More than 40% of these infections lasted 2-6 wk or more and were commonly associated with diarrhea. Weight velocity was significantly lower in the second year of life in Giardia-infected than in Giardia-negative children (p = 0.03). The duration of Giardia episodes and their association with diarrhea appeared to be the most important factors associated with growth disturbance. Although simultaneous infection with other enteropathogens occurred in many children, our findings suggest that Giardia infection may have independent deleterious effects on children's growth.     

Effect of an iron fortified milk on morbidity in infancy. A field trial

The effect of an iron fortified milk on gastrointestinal and respiratory illness was evaluated in a prospective longitudinal field trial in which infants were provided beginning at 3 and continuing through 15 months of age with, either iron fortified 15 mg Fe/l (n=53) or non fortified (n=47) milk. Gastrointestinal and respiratory symptoms and signs were recorded daily. The mean incidence of diarrhea was 1.1 and 1.2 episodes per year per child in the fortified and non fortified groups, respectively. The figures per child/year for respiratory infections were 3.9 and 3.9 respectively. The results demonstrate that iron fortification at doses sufficient to significantly eradicate iron deficiency anemia is not associated with an increased incidence of gastrointestinal and respiratory illness.     

Effect of fermented milk containing the probiotic Lactobacillus casei DN-114001 on winter infections in free-living elderly subjects: a randomised,controlled pilot study

Probiotics are being increasingly studied for their ability to enhance host resistance to, and recovery from, infection. The probiotic strain Lactobacillus casei DN-114001 has previously been shown to reduce the incidence and duration of episodes of diarrhoea in children. Our controlled pilot study aimed to evaluate the effect of supplementation for 3 weeks with milk fermented with yoghurt cultures and L. casei DN-114001 on the incidence and severity of winter infections (gastrointestinal and respiratory) in elderly people. We found no difference in the incidence of winter infections between groups. However, duration of all pathologies was significantly lower in the treatment group (7.0 3.2 days, n=180) than in the control group (8.7 3.7 days; n=180) (p=0.024), as was maximal temperature (38.3 0.5 C treatment group vs. 38.5 0.6 C control; p=0.01). The potential for a 20% reduction in the duration of winter infections that we have found warrants further investigation on a larger scale.     

Longitudinal study of rotavirus infections among children from Belém, Brazil

From December 1982 to March 1986 a group of 80 children between 0 and 3 years old who lived in the peripheral area of Belém, Brazil, were followed up for episodes of diarrhoea. A total of 441 diarrhoeal episodes were recorded and 36 (8.2%) were associated with rotavirus. This agent was the only pathogen in 50% of rotavirus-related episodes of acute diarrhoea, and strains were characterized by analysis of RNA in polyacrylamide gels. Forty-one belonged to subgroup II (long pattern) and five to subgroup I. Reinfections by rotavirus were noted in 12 children involving either the same or different subgroups. Ten distinct electrophoretypes were detected in the study period and the predominant one had the '1N2L' profile. The cumulative age-specific attack rate for diarrhoea reached 2.8 by the end of the first year of life; a frequency of 2.3 episodes of diarrhoea per child per year was observed throughout the complete investigation. In comparing the age-specific attack rates for diarrhoea between breast-fed and bottle-fed children, a peak at 6 months of age was noted in the former, and at 1 month in the latter. A comparison by Fischer's exact test (P = 0.21) provided no evidence for protection against clinical rotavirus disease by maternal milk. By the same test, however (P = 0.021), we found significant evidence that early rotavirus infections were more likely to be asymptomatic and that infections after 4 months were more likely to be symptomatic. The clinical picture in children with rotavirus-related diarrhoea was more severe than in those suffering from acute diarrhoea due to another agent.     

Prognostic indicators and risk factors for increased duration of acute diarrhoea and for persistent diarrhoea in children.

To identify the prognostic indicators and risk factors for increased duration of acute diarrhoea and for occurrence of persistent diarrhoea (i.e. acute episodes lasting longer than 14 days) in children under three years, a systematic sample (3690) of patients attending a large treatment centre in Bangladesh was analysed using multiple regression, logistic regression and stratified (Mantel-Haenszel) analysis. Significant prognostic indicators or risk factors for increase in duration of acute diarrhoea, after adjusting for confounders, include bloody or mucoid diarrhoea, concomitant signs of chest infection, presence of vitamin A deficiency signs, decreased weight for age, routine use of contaminated surface water, lack of breastfeeding and increasing age; presence of rotavirus or enterotoxigenic Escherichia coli or Vibrio cholerae 01 in stool had negative association. In logistic regression and stratified analysis these factors, except for lack of breastfeeding and age, were also found to be risk factors or prognostic indicators of persistent diarrhoea. Policy implications of these findings for programmes to reduce morbidity and mortality from persistent diarrhoea include development of effective vaccines against dysentery-causing Shigella, programmes to prevent vitamin A deficiency, protein energy malnutrition and acute respiratory infections in children, and long-term programmes to provide clean water for all day-to-day needs.     

Risk factors for overall and persistent diarrhoea in infancy in Antalya, Turkey: a cohort study

The aim of this study was to identify factors that influence the incidence of diarrhoea in infancy. The study was a prospective cohort study conducted in two primary healthcare unit areas in Antalya, Turkey. A total of 204 infants were followed until they were aged 1 year. Morbidity surveillance and anthropometric measurements were carried out by home visits every 2 months. The average incidences were found to be 2.76 episodes per child-year for overall diarrhoea and 18.56 episodes per 100 child-years for persistent diarrhoea. Relative risks, confidence intervals and logistic regression analyses were used to assess the associations. For both overall diarrhoea and persistent episodes, increased risks were associated with having an uneducated mother (RR=1.89 and 5.33, respectively) and a self-employed father (RR=1.89 and 3.77, respectively). Among environmental factors, living in a slum was associated with both overall (RR=1.68) and persistent (RR=2.69) diarrhoea, whereas living in a crowded house (RR=1.70), having no kitchen (RR=2.27) or having an unhygienic toilet (RR=1.93) were found to be significant for overall episodes alone. Factors related to the infant were preterm birth (RR=1.64), low birth weight (RR=2.05), and first breastfeed given more than 1 h after birth (RR=1.64). Nutritional status was also associated with overall or persistent diarrhoea: underweight children (RR=2.15, persistent diarrhoea only), stunted children (RR=1.67 and 2.14, respectively) or wasted children (RR=1.54 and 3.20, respectively). By logistic regression analysis, both overall and persistent diarrhoea were found to be associated with mother's education.     

Longitudinal studies of infectious diseases and physical growth of infants in Huascar, an underprivileged peri-urban community in Lima, Peru

Longitudinal studies of morbidity from infectious diseases and physical growth were completed from July 1982-June 1984 for 153 Peruvian newborns during the first year of life. Admission to the cohort was restricted to infants with birth weights greater than 2,500 g. Surveillance workers inquired about symptoms of diarrheal, respiratory, and other illnesses during thrice-weekly home visits; anthropometrists measured weight and length each month to assess the infants' patterns of physical growth and relative nutritional status. During 48,209 child-days of observation, upper respiratory infections were present on 13,409 child-days (27.8% prevalence) and diarrhea on 7,466 child-days (15.5% prevalence). The diarrhea incidence rate averaged 9.8 episodes per child-year of observation; all children had at least one episode of diarrhea. Average weights approximated those of the National Center for Health Statistics reference population during the first five to six months, but declined thereafter in relation to reference data. Average lengths were less than the reference data at all ages. The average weights for age and lengths for age of girls were generally greater than those of boys relative to the reference population. Rates of stunting and wasting increased progressively during the first year of life.     

Effectiveness of influenza vaccination of children with recurrent respiratory tract infections in reducing respiratory-related morbidity within the households

To evaluate the effectiveness of influenza vaccination in reducing respiratory-related morbidity among children with recurrent respiratory tract infections (RRTIs) and their household contacts, 127 children aged 6 months-9 years (78 males; median age, 3.7 years) with a history of RRTIs (>/=6 episodes per year if aged >/=3 years; >/=8 episodes per year if aged <3 years) were randomized to receive the intranasal virosomal influenza vaccine (n=64 with 176 household contacts) or a control placebo (n=63 with 173 household contacts). During influenza season, the vaccinated children had fewer respiratory infections, febrile respiratory illnesses, prescribed antibiotics and antipyretics, and missed school days than the controls, and similar benefits and a reduction in the loss of parental work were observed among their household contacts. This study shows that the benefits of influenza vaccination extend to children with RRTIs and their family members and encourages to recommend its use in such children.