Risk of diarrheal disease in Ecuadorian day-care centers

Centre-based day care for children younger than five years of age in low- and middle-income countries

BACKGROUND

Because of poverty, children and families in low- and middle-income countries often face significant impediments to health and well-being. Centre-based day care services may influence the development of children and the economic situation of parents by providing good quality early childhood care and by freeing parents to participate in the labour force.

OBJECTIVES

To assess the effects of centre-based day care without additional interventions (e.g. psychological or medical services, parent training) on the development, health and well-being of children and families in low- and middle-income countries (as defined by the World Bank 2011).

SEARCH METHODS

In April 2014, we searched CENTRAL, Ovid MEDLINE, EMBASE, PsycINFO, ERIC and 16 other sources, including several World Health Organization (WHO) regional databases. We also searched two trials registers, websites of government and non-government agencies and reference lists of relevant studies.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials and prospective non-randomised studies with contemporaneous control groups and assessments both before and after intervention. We considered non-randomised controlled trials, as centre-based care in low- and middle-income countries is unlikely to be studied using randomised controlled trials (Higgins 2011). We included the following outcomes: child intellectual development, child psychosocial development, maternal and family outcomes and incidence of infectious diseases.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risk of bias and extracted data from the single included study.

MAIN RESULTS

Only one trial, involving 256 children, met the inclusion criteria for this review. This study was assessed as having high risk of bias because of non-random allocation, incomplete outcome data and insufficient control of confounding factors. Results from this study suggest that centre-based day care may have a positive effect on child cognitive ability compared with no treatment (care at home) (assessed using a modified version of the British Ability Scale-II (BAS-II) (standardised mean difference (SMD) 0.74, 95% confidence interval (CI) 0.48 to 1.00, 256 participants, 1 study, very low-quality evidence). This study did not measure other variables relevant to this review.

AUTHORS' CONCLUSIONS

The single study included in this review provides limited evidence on the effects of centre-based day care for children younger than five years of age in low- and middle-income countries. This study was at high risk of bias and may have limited generalisability to other low- and middle-income countries. Many of the studies excluded from this review paired day care attendance with co-interventions that are unlikely to be provided in normal day care centres. Effectiveness studies on centre-based day care without these co-interventions are few, and the need for such studies is significant. In future studies, comparisons might include home visits or alternative day care arrangements.

Systematic review of diarrhea duration and severity in children and adults in low- and middle-income countries

Background

Diarrhea is a leading cause of morbidity and mortality globally; yet the overall burden of diarrhea in terms of duration and severity has not been quantified. As improvements in treatment lead to decreases in diarrhea mortality, it is important to understand the substantial impact of diarrhea morbidity on disability among children and adults worldwide.

Methods

We conducted a systematic review to generate estimates of duration and severity outcomes for individuals 0-59 mos, 5-15 yrs, and ≥ 16 yrs, and for 3 severity indexes: mild, moderate, and severe.

Results

We estimate that among children under-five, 64.8% of diarrheal episodes are mild, 34.7% are moderate, and 0.5% are severe. On average, mild episodes last 4.3 days, and severe episodes last 8.4 days and cause dehydration in 84.6% of cases. We estimate that among older children and adults, 95% of episodes are mild; 4.95% are moderate; and 0.05% are severe. Among individuals ≥ 16 yrs, severe episodes typically last 2.6 days and cause dehydration in 92.8% of cases.

Conclusions

Moderate and severe episodes constitute a substantial portion of the total envelope of diarrhea among children under-five (35.2%; about 588 million episodes). Among older children and adults, moderate and severe episodes account for a much smaller proportion of the total envelope of diarrhea (5%), but the absolute number of such episodes is noteworthy (about 21.5 million episodes among individuals ≥ 16 yrs). Hence, the global burden of diarrhea consists of significant morbidity, extending beyond episodes progressing to death.

Diarrhea and colds in child day care centers: impact of various numerator and denominator definitions of illness episodes

BACKGROUND

Numerators and denominators used to estimate infections' incidence rates (IRs), incidence rate ratios (IRRs), and differences (IRDs) vary. Our objective is to quantify the impact of various common definitions for illness episodes (numerators) and person-time at risk (denominators) in estimating these measures.

METHODS

Data were from a cohort study in which daily occurrence of illness and children's attendance in day care centers were recorded. We compared 4 IR estimates using various definitions of episode and at-risk time units.

RESULTS

IRs for diarrhea and colds were highest using child-days, lowest for diarrhea using child-weeks, and lowest for colds using child-months. The 4 methods led to similar IRRs but considerably different IRDs.

CONCLUSION

Incidence rate differences and ratios for infectious diseases can vary by the definition of episode and person-time at risk. This limits the value of the evidence base on which public health recommendations are formulated. Development of a more standard approach to measurement and reporting of IRs is recommended.

[Epidemiology and burden of rotavirus diarrhea in day care centers in Lyon, France]

Rotavirus is the main cause of severe, dehydrating diarrhoea in infants and young children. In industrialized countries, pediatric rotavirus gastroenteritis (PRGE) is responsible for high morbidity, particularly among children under 3 years of age attending day care centers (DCCs). The objectives of this study were to estimate the incidence, management and cost of PRGE in DCCs. We also described the nature of group A rotavirus genotypes. This study also compared the performance of different diagnostic techniques. The study was conducted from November 2004 to May 2005. Children aged less than 36 months, attending a participating DCC at least 4 times a week were included in the study. For any episode of acute gastroenteritis (AGE), defined as the occurrence of 3 or more watery or looser than normal stools and/or forceful vomiting within a 24 h period, a fecal specimen was tested by Elisa test IDEIA Rotavirus (Dako) and the immunochromatographic test VIKIA Rota-Adeno (BioMérieux). Sequencing by RT-PCR was performed to identify the rotavirus genotype. Among the 41 DCCs contacted, 18 (43.9%) agreed to participate. Out of 966 children, 547 attended a participating DCC at least 4 times a week and met the inclusion criteria. A total of 302 were included in the study. The clinical diagnosis of AGE was confirmed and validated, by the Elisa test, in 63 fecal specimens, of which 29 (46%) were positive for rotavirus antigen, with a predominance of P[8]G9 (86%). Our results showed good sensitivity and specificity for the VIKIA and Elisa methods when compared to RT-PCR. Among the PRGE cases, 36% were male and the median age was 12.2 months. The first rotavirus case was observed in December 2004 with a peak in January 2005. The incidence of PRGE cases was 2.2 [1.4-3.0] per 100 child-months in children aged less than 36 months of age, increasing to 3.4 per 100 child-months among children aged less than 24 months. Vomiting (P<0.0005) and behavior modification (P<0.001) were significantly more frequent for PRGE cases. A total of 85.7% PRGE cases sought medical attention. In 58.3% of these cases, at least one parent had to miss work for a mean duration of 2.1 days. The total cost of rotavirus cases seeking medical attention (with or without prescribed medication, days off work for parents or additional diaper consumption) was estimated at 275.54 euros/case. The PRGE incidence rate is similar to that estimated in European studies conducted in DDC. These findings confirm that rotavirus transmission occurs not only in DCCs but within the family. This is the first study to give an estimate of the incidence and the cost of rotavirus infection in DCCs in France.

Integrating disease control strategies: balancing water sanitation and hygiene interventions to reduce diarrheal disease burden

OBJECTIVES

Although the burden of diarrheal disease resulting from inadequate water quality, sanitation practices, and hygiene remains high, there is little understanding of the integration of these environmental control strategies. We tested a modeling framework designed to capture the interdependent transmission pathways of enteric pathogens.

METHODS

We developed a household-level stochastic model accounting for 5 different transmission pathways. We estimated disease preventable through water treatment by comparing 2 scenarios: all households fully exposed to contaminated drinking water and all households receiving the water quality intervention.

RESULTS

We found that the benefits of a water quality intervention depend on sanitation and hygiene conditions. When sanitation conditions are poor, water quality improvements may have minimal impact regardless of amount of water contamination. If each transmission pathway alone is sufficient to maintain diarrheal disease, single-pathway interventions will have minimal benefit, and ultimately an intervention will be successful only if all sufficient pathways are eliminated. However, when 1 pathway is critical to maintaining the disease, public health efforts should focus on this critical pathway.

CONCLUSIONS

Our findings provide guidance in understanding how to best reduce and eliminate diarrheal disease through integrated control strategies.

Risk factors for shigellosis in Thailand

OBJECTIVES

To assess the potential risk factors for shigellosis including housefly density.

METHODS

A matched case-control study to investigate potential risk factors for shigellosis was conducted in a semi-urban area, Kaengkhoi District, Saraburi Province, central Thailand. Shigella cases were ascertained from a two-year population-based surveillance study detecting diarrhea and shigellosis in the area. The study evaluated a wide range of exposures, which were assessed by odds ratios (OR) adjusted for proxy markers of socioeconomic status: family income, and type of residence, using conditional logistic regression analysis.

RESULTS

Hygiene behaviors such as regular hand washing (p<0.05), a clean environment surrounding the household (p<0.001), and the availability of water to flush the toilet (p=0.08) were associated with a reduced risk for shigellosis in the multivariate model. In contrast factors indicating a lower than average socioeconomic status, such as having to rent instead of owning one's housing (p<0.001) and a low family income (p<0.01) were associated with an increased risk for shigellosis. For children, breastfeeding showed a strong protective effect in reducing the risk of shigellosis (p<0.01). Prior to adjustment for environmental factors, fly density in the kitchen area was associated with an increased risk of shigellosis (p<0.01).

CONCLUSIONS

We found a correlation between socioeconomic status and the risk for shigellosis. To reduce shigellosis in this setting, we recommend interventions focused on three aspects: improved water supply and sanitation (especially latrines and garbage disposal) including fly control, health education on hand washing, and the promotion of breastfeeding.

What is the evidence for a causal link between hygiene and infections?

Even in an era in which access to personal "cleanliness" and a public health infrastructure are readily available in developed countries, illnesses associated with day care centres and homes continue to be a problem. The inhabitants of less developed countries, on the other hand, must contend with an inadequate public health infrastructure, lack of education programmes, and economic limitations in obtaining hygiene products. Therefore, less developed countries carry a greater burden of morbidity and mortality from infectious illnesses. The objective of this review is to examine and assess the epidemiological evidence for a causal relation between hygiene practices and infections. The Medline database was searched from January 1980 to June 2001 and studies were included if the outcome(s) was infection or symptoms of infection, and if the independent variable(s) was one or more hygiene measures. The strength of the association as measured by the relative reduction in risk of illness was appreciable and generally greater than 20%. Despite methodological strengths and limitations of the studies assessed, the weight of evidence collectively suggests that personal and environmental hygiene reduces the spread of infection. The results from this review demonstrate that there is a continued, measurable, positive effect of personal and community hygiene on infections.

A longitudinal study of Giardia lamblia infection in north-east Brazilian children

OBJECTIVE

To evaluate the epidemiology of Giardia lamblia infection, investigate factors which might be associated with clinical manifestations and recurrence, and examine the role of copathogens in disease course.

METHODS

Prospective 4-year cohort study of children born in an urban slum in north-eastern Brazil.

RESULTS

Of 157 children followed for > or = 3 months, 43 (27.4%) were infected with Giardia. The organism was identified in 8.8% of all stool specimens, and although found with similar frequency in non-diarrhoeal (7.4%) and diarrhoeal stools (9.7%), was more common in children with persistent (20.6%) than acute diarrhoea (7.6%, P=0.002). Recurrent or relapsing infections were common (46%). Children with symptomatic infections had significantly lower weight-for-age and height-for-age than asymptomatic children. Copathogens were not associated with disease course. CONCLUSION With its protean clinical manifestations, Giardia may be associated with substantial morbidity amongst children in Brazil.

Asymptomatic salmonellosis among children in day-care centers in Mérida, Yucatan, Mexico

BACKGROUND

Child day-care centers (DCC) have become common in many lower and middle income countries, presenting new problems that may differ from those of DCC in more developed countries. Diarrhea is a common problem in DCC in the United States, but information on the prevalence of diarrhea or specific enteropathogens among children in DCC in tropical and developing countries is limited.

METHODS

Because of preliminary data from newborns and DCC attendees in Mérida, Mexico, with high rates of Salmonella infection, we conducted a 12-month longitudinal surveillance study of enteropathogens in two Mérida DCC. Seventy-eight children ages 2 months to 4 years were evaluated with demographic and clinical data, and stools were cultured monthly.

RESULTS

Salmonella sp. was the most common enteropathogen detected (46 of 683 specimens, 6.7%), with higher rates in children younger than 18 months (P < 0.02), but it was found in only 1 of 10 diarrhea episodes that coincided with sampling. Other common organisms identified included Giardia lamblia (21 of 683, 3.0%) and LT-producing enterotoxigenic Escherichia coli (16 of 683, 2.3%). Salmonella was recovered from as many as 19% of children in a single month, but the large multiplicity of serotypes recovered suggested multiple sources rather than a common source outbreak. Children with Salmonella tended to have more liquid stools during the preceding 2 weeks. Salmonella was also isolated from the stool of teachers in 1 of the 2 DCC in 10 of 94 specimens (10.6%), and again multiple serotypes were represented.

CONCLUSION

These data indicate the presence of multiple sources of Salmonella infection in the DCC, posing a complex situation for infection control.

Hygiene of the skin: when is clean too clean?

Skin hygiene, particularly of the hands, is a primary mechanism for reducing contact and fecal-oral transmission of infectious agents. Widespread use of antimicrobial products has prompted concern about emergence of resistance to antiseptics and damage to the skin barrier associated with frequent washing. This article reviews evidence for the relationship between skin hygiene and infection, the effects of washing on skin integrity, and recommendations for skin care practices.

The beneficial effects of weekly low-dose vitamin A supplementation on acute lower respiratory infections and diarrhea in Ecuadorian children

BACKGROUND

Previous studies of large-dose vitamin A supplementation on respiratory morbidity have produced conflicting results in a variety of populations. The influence of malnutrition has not been examined in the majority of these trials. We hypothesized that weekly low-dose vitamin A supplementation would prevent respiratory and diarrheal disease morbidity and that malnutrition might influence the efficacy of vitamin A supplementation.

METHODS

In a randomized, double-blind, placebo-controlled field trial of 400 children, 6 to 36 months of age in a high Andean urban slum, half of the children received 10 000 IU of vitamin A weekly and half received placebo for 40 weeks. Children were visited weekly at home by physicians and assessed for acute diarrheal disease and acute respiratory infections.

RESULTS

Acute diarrheal disease and acute respiratory infection did not differ globally or by severity between supplement-treated and placebo groups. However, the incidence of acute lower respiratory infection (ALRI) was significantly lower in underweight (weight-for-age z score [WAZ] <-2 SD) supplement-treated children than in underweight children on placebo (8.5 vs 22.3 per 10(3) child-weeks; rate ratio: 0.38 [95% CI: 0.17-0.85]). ALRI incidence was significantly higher in normal-weight (WAZ >-2 SD) supplement-treated children than in normal-weight children on placebo (9.8 vs 4.4 per 10(3) child-weeks; rate ratio: 2.21 [95% CI: 1.24-3.93]). By logistic regression analysis the risk of ALRI was lower in underweight supplement-treated children than in underweight children on placebo (point estimate 0.148 [95% CI: 0.034-0.634]). In contrast, risk of ALRI was higher in normal-weight supplement-treated children (WAZ >-1 SD to mean) than in normal-weight children on placebo in the same WAZ stratum (point estimate: 2.51 [95% CI: 1.24-5.05]). The risk of severe diarrhea was lower in supplement-treated children 18 to 23 months of age than in children on placebo in this age group (point estimate: 0.26 [95% CI: 0.06-1.00]).

CONCLUSIONS

Weekly low-dose (10 000 IU) vitamin A supplementation in a region of subclinical deficiency protected underweight children from ALRI and paradoxically increased ALRI in normal children with body weight over -1 SD. Protection from severe diarrhea was consistent with previous trials. Additional research is warranted to delineate potential beneficial and detrimental interactions between nutritional status and vitamin A supplementation regarding ALRI.