A review of the effects of breastfeeding on respiratory infections, atopy, and childhood asthma

Allergic disorders in African countries: linking immunology to accurate phenotype

Identification and characterization of risk and protective factors for allergy is important for developing strategies for prevention or treatment. The prevalence of allergy is clearly higher in affluent countries than in developing countries like, e.g. Africa. Especially in urban areas of developing countries, allergy is however on the increase. In Africa, we have the unique opportunity to investigate risk and protective factors and the influence of urbanization and westernization, i.e. almost to take a look at Europe, Australia or the USA as they were before their allergy epidemics. Moreover, migrants from developing to affluent countries experiencing an increased burden of allergy provide new insights into risk and protective factors. Allergen exposure, diet and infections are the major exogenous influences playing a role as risk and protective factors. Depending on the nature, timing, chronicity and level of exposure, each of them can promote or inhibit allergy. Perhaps with the exception of infections, availability of data from Africa on their role in the development of allergy is limited. Detailed epidemiological studies in rural and urban Africa combined with basic immunological research are needed to unravel mechanisms of increase in allergy and of protection. The maturation of the immune system at young age under influence of exogenous factors results in differences in T-cell-skewing (Th1/Th2/Treg) and humoral responses. It is essential to perform studies from a 'non-Eurocentric' angle (e.g. local allergens, locally validated questionnaires and diagnostic procedures). Such studies will provide the affluent countries with new leads to combat the allergy epidemic and more importantly help prevent it in Africa.

Simple Antenatal Preparation to Improve Breastfeeding Practice

OBJECTIVE

To address the impact of simple antenatal educational interventions on breastfeeding practice.

METHODS

A randomized controlled trial was carried out in a tertiary referral center from May 2002 to December 2004. A random sample of eligible low-risk antenatal patients was recruited from clinics in the National University Hospital, Singapore. Group A received breastfeeding educational material and individual coaching from a lactation counselor. Group B received breastfeeding educational material with no counseling. Group C received routine antenatal care only.

RESULTS

A total of 401 women were recruited. Mothers receiving individual counseling and educational material practiced exclusive and predominant breastfeeding more often than mothers receiving routine care alone at 3 months (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.2-5.4) and 6 months (OR 2.4, 95% CI 1.0-5.7) postpartum. More mothers practiced exclusive and predominant breastfeeding at 6 months among women receiving individual counseling compared with women exposed to educational material alone (OR 2.5, 95% CI 1.0-6.3).

CONCLUSION

Where breastfeeding practices are suboptimal, simple one-encounter antenatal education and counseling significantly improve breastfeeding practice up to 3 months after delivery. Provision of printed or audiovisual educational material is not enough. Health care workers should make every effort to have one face-to-face encounter to discuss breastfeeding with expectant mothers before they deliver.

CLINICAL TRIAL REGISTRATION

(www.ClinicalTrials.gov), NCT002770192

LEVEL OF EVIDENCE

I.

Effect of diet on the development of drug metabolism by cytochrome P-450 enzymes in healthy infants

Orally administered caffeine and dextromethorphan (DM) were used as pharmacologic probes to determine the effect of infant diet on acquisition of cytochrome P-450 (CYP) enzyme activity during the first 6 mo of life. The caffeine elimination rate constant (ke) was determined from serum, and concentrations of caffeine, DM, and their respective metabolites were measured in urine by high-performance liquid chromatography (HPLC). Caffeine ke was low at 2 wk and displayed a significant positive linear correlation with age (p < 0.001); increasing faster in formula-fed than in breast-fed infants (p < 0.001). This occurred concomitantly with a significant increase in urinary 1,7-dimethylxanthine (17X) and 1-methylxanthine (1X) (p < 0.001), suggesting faster acquisition of CYP1A2 activity in formula-fed infants. The urinary molar ratio of (17X + 1X)/caffeine and age strongly predicted caffeine ke (r2 = 0.65; p < 0.001) irrespective of feeding type. CYP3A4 activity, assessed as the molar ratio of 3-hydroxymorphinan/dextrorphan showed a similar marked increase with postnatal age (p < 0.001) that was also greater in formula-fed than in breast-fed infants. Formula feeding appears to accelerate maturation of caffeine and DM metabolism by increasing the activity of CYP1A2 and CYP3A4, respectively. Dietary modification of CYP activity may modulate drug biotransformation and thus alter systemic exposure to xenobiotics from a very early age.

A randomised-controlled trial in Sweden of acupuncture and care interventions for the relief of inflammatory symptoms of the breast during lactation

OBJECTIVES

to further compare acupuncture treatment and care interventions for the relief of inflammatory symptoms of the breast during lactation and to investigate the relationship between bacteria in the breast milk and clinical signs and symptoms.

DESIGN

randomised, non-blinded, controlled trial of acupuncture and care interventions.

SETTING

a midwife-led breast feeding clinic in Sweden.

PARTICIPANTS

205 mothers with 210 cases of inflammatory symptoms of the breast during lactation agreed to participate. The mothers were randomly assigned to one of three treatment groups, two of which included acupuncture among the care interventions and one without acupuncture. All groups were given essential care. Protocols, which included scales for erythema, breast tension and pain, were maintained for each day of contact with the breast feeding clinic. A Severity Index (SI) for each mother and each day was created by adding together the scores on the erythema, breast tension and pain scales. The range of the SI was 0 (least severe) to 19 (most severe).

FINDINGS

no significant difference was found in numbers of mothers in the treatment groups, with the lowest possible score for severity of symptoms on contact days 3, 4 or 5. No statistically significant differences were found between the treatment groups for number of contact days needed until the mother felt well enough to discontinue contact with the breast feeding clinic or for number of mothers prescribed antibiotics. Significant differences were found in the mean SI scores on contact days 3 and 4 between the non-acupuncture group and the two acupuncture groups. Mothers with less favourable outcomes (6 contact days, n=61) were, at first contact with the midwife, more often given advice on correction of the baby's attachment to the breast. An obstetrician was called to examine 20% of the mothers, and antibiotic treatment was prescribed for 15% of the study population. The presence of Group B streptococci in the breast milk was related to less favourable outcomes.

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

if acupuncture treatment is acceptable to the mother, this, together with care interventions such as correction of breast feeding position and babies' attachment to the breast, might be a more expedient and less invasive choice of treatment than the use of oxytocin nasal spray. Midwives, nurses or medical practitioners with specialist competence in breast feeding should be the primary care providers for mothers with inflammatory symptoms of the breast during lactation. The use of antibiotics for inflammatory symptoms of the breast should be closely monitored in order to help the global community reduce resistance development among bacterial pathogens.

Asthma prevalence in Hispanic and Asian American ethnic subgroups: results from the California Healthy Kids Survey

OBJECTIVES

Asthma prevalence for different ethnic groups in the United States, beyond white, black and Hispanic, is seldom reported. We compared the prevalence of asthma diagnosis among various Hispanic and Asian American ethnic subgroups using data collected from the school-based California Healthy Kids Survey.

METHODS

The California Healthy Kids Survey was administered to 462 147 public school students in the seventh, ninth, and 11th grades throughout California during the 2001-2002 and 2002-2003 school years. Prevalence of lifetime asthma diagnosis was calculated for 11 Asian American Pacific Islander subgroups and 8 Hispanic subgroups.

RESULTS

Asthma prevalence among Hispanic subgroups ranged from 13.2% for Mexican American students to 22.8% for Puerto Rican students and 23.0% among Cuban American students. Lifetime asthma diagnosis among the 11 Asian American Pacific Islander subgroups ranged from 10.9% among Korean American students to 23.8% among Filipino American students.

CONCLUSIONS

The survey revealed substantial variation in asthma prevalence between the different Hispanic and Asian American Pacific Islander subgroups and that Pacific Islanders, Filipinos, Cubans, and Puerto Ricans are at elevated risk for asthma. Differences in the distributions of characteristics related to country of birth, residential history, generational status, and/or degree of acculturation might account for much of the observed differences in asthma prevalence between ethnic subgroups. Previous asthma prevalence estimates for Asians or Hispanics are in part a function of the particular ethnic composition of the population under investigation. We suggest that asthma studies that include a substantial number of Asian Pacific Islander and Hispanic persons use a more detailed categorization of race/ethnicity.

The role of helminth infections in protection from atopic disorders

PURPOSE OF REVIEW

The observation that allergies are less prevalent in developing countries, especially in rural areas, has stimulated considerable research to identify environmental factors associated with protection against allergic disorders. Here, we review recent studies conducted in developing countries.

RECENT FINDINGS

Epidemiological studies conducted in South America, Asia and Africa have attempted to identify factors associated with differences in prevalence of atopy, asthma and atopic dermatitis. Particular attention is given to the complex relationship between helminth infections and allergies. In answer to the question of whether helminth infections are associated with protection against allergic disorders, conflicting data have been generated. In addition to epidemiological studies, animal models have been utilized to gain insight into the immunological mechanisms involved in the interaction between helminth infections and allergies. These animal studies are discussed. The possible explanations for discrepancies found within both human and murine studies have been considered, highlighting the need for further research.

SUMMARY

An in-depth understanding of the relevant protective mechanisms against allergic disorders will open the possibility of developing novel therapeutics to prevent the allergic march worldwide.

Early consumption of human milk oligosaccharides is inversely related to subsequent risk of respiratory and enteric disease in infants

A pilot study tested the relationship between human milk oligosaccharide consumption, oligosaccharide content of feces, and subsequent disease in breastfed infants. Forty-nine (49) mother-infant pairs provided milk and fecal samples 2 weeks postpartum; infant health was assessed through 2, 6, 12, and 24 weeks. LNF-II (lacto-N-fucopentaose II), a major human milk oligosaccharide, was measured to represent levels of total oligosaccharides consumed in milk and remaining in feces. LNF-II levels in milk at 2 weeks postpartum were associated with fewer infant respiratory problems by 6 weeks (p = 0.010), as were LNF-II levels in infant feces (p = 0.003). LNF-II levels in milk at 2 weeks were also associated with fewer respiratory problems by 12 weeks (p = 0.038), and fewer enteric problems by 6 weeks (p = 0.004) and 12 weeks (p = 0.045). Thus, consumption of human milk oligosaccharides through breastfeeding, represented by LNF-II, was associated with less reported respiratory and gastrointestinal illness in infants.

Prevalence of probable mental disorders among pediatric asthma patients in an inner-city clinic

OBJECTIVE

To determine the screen-positive prevalence of anxiety disorders and depression among pediatric asthma patients in an inner-city asthma clinic and to investigate the association between probable diagnoses of anxiety disorders and depression and medical service use among inner-city pediatric asthma patients.

METHOD

In this pilot study, a consecutive sample of pediatric asthma patients aged 5-11 in the waiting room of an inner-city asthma clinic was screened for mental disorders using the DISC Predictive Scales (DPS), which produces probable DSM-IV diagnoses. In addition, data on health service use for asthma were collected. Statistical analyses were performed to examine the relationship between probable anxiety disorders and depression and health service use for asthma among pediatric asthma patients.

RESULTS

Approximately one in four (25.7%) pediatric asthma patients in an inner-city asthma clinic met criteria for a probable diagnosis of current anxiety disorders or depression (past 4-week prevalence). Specifically, childhood separation anxiety disorder was common among 8.1%, panic among 14.9%, generalized anxiety disorder among 4.1%, agoraphobia among 5.4%, and 2.7% had depression. Having more than one anxiety disorder or depression diagnosis was associated with higher levels of inpatient and outpatient medical services, compared with patients who were negative on screening for anxiety or depressive disorders, although differences failed to reach statistical significance.

CONCLUSIONS

These findings are the first to provide preliminary evidence suggesting that mental health problems are common among pediatric asthma patients in an inner-city clinic. The results also suggest that mental health problems in pediatric asthma patients may be associated with elevated levels of medical service use for asthma. Replication of this pilot study is needed with a larger sample, more precise diagnostic methodology, and a comparison group with chronic medical illness.

Breastfeeding duration is determined by only a few factors

BACKGROUND

According to a representative German study prepared between 1996 and 1998 (SuSe-Study) 90% of the mothers were willing to breastfeed, but only 33% (10%) of the babies were exclusively breastfed up to 4 (6) months of age. Bearing in mind that the period currently recommended for breastfeeding is 6 months, this discrepancy highlights the need for action to identify the causes. The present study investigates the behavioural pattern of mothers 4-5 months after delivery.

METHODS

The investigation was carried out as a cross-sectional study of mothers who intended to breastfeed their babies (n = 52). All mothers delivered in a hospital, with maximum medical care, and were interviewed later by telephone using a semi-standardised questionnaire. The differences between actual breastfeeding mothers (BF, n = 30) and non-breastfeeding mothers (not BF, n = 22) were identified. The factors influencing decision-making were determined.

RESULTS

Significant differences between the two groups tested (BF and not BF) were identified as the perception of the simplicity of breastfeeding, planned pregnancy, marital status, as well as participation at birth preparation classes. If only factors known prior to birth are applied, the decision to breastfeed can be correctly forecast as being 81%.

CONCLUSION

In order to allocate consulting resources more effectively, appropriate concepts need to be developed and promoted. If the present results could be verified by a study with a larger sample, the practical use for resource optimisation in breastfeeding consultations would be very beneficial.

Risk factors for asthma and atopy

PURPOSE OF REVIEW

The aim of this article is to provide information on risk factors associated with the development of atopy and asthma in childhood.

RECENT FINDINGS

Several gene polymorphisms have been associated with susceptibility to asthma and allergy; complex gene-environmental interactions, however, appear to play a key role in the development of the disease. Early life sensitization to aeroallergens, presence of atopic dermatitis or allergic rhinitis, maternal smoking during pregnancy and children's environmental exposure to tobacco smoke, lower respiratory tract infections with respiratory syncytial virus and potentially with other viruses including rhinovirus and metapneumovirus, exposure to air pollutants, several perinatal factors other than maternal smoking, are among factors associated with an increased risk for development of chronic asthma.

SUMMARY

The prevalence of asthma and allergic diseases is increasing progressively. Those who are involved in the care of young children should be prepared to recognize risk factors for development of these diseases and to appreciate the role of gene-environment interactions. Preventive measures established at an early age may modify the natural history of asthma and other allergic diseases.