High levels of anti-Campylobacter-flagellin IgA antibodies in breast milk

Avoidance of antibiotic administration to Campylobacter enterocolitis mimicking severe salmonellosis by clinical and laboratory features

BACKGROUND

To compare the clinical and laboratory features of non-typhoid Salmonella (NTS) and Campylobacter jejuni enterocolitis in children and formulate a risk scoring system (with receiver-operating characteristic curve) to facilitate early decision making and avoid antibiotic overuse in C. jejuni enterocolitis.

METHODS

Between January 2008 and December 2011, children (age <18 years) diagnosed as having C. jejuni enterocolitis and NTS enterocolitis in Kaohsiung Chang Gung Memorial Hospital were retrospectively enrolled. Clinical features and laboratory data were collected for analysis and a risk calculation score is created for the identification of Campylobacter infections.

RESULTS

A total of 309 cases of C. jejuni enterocolitis and 496 cases of NTS enterocolitis were enrolled. Compared with Salmonella group clinically, the Campylobacter group had older age (81.06 ± 50.65 vs. 32.70 ± 34.88 months, p <; 0.001), more abdominal pain (69.26% vs. 37.5%, p <; 0.001) and more watery diarrhea (79.94% vs. 20.77%, p <; 0.001). In laboratory data, the Campylobacter group had higher level of white blood cell count (11 208 ± 4380 vs. 9095 ± 3598 cell/mm3, p <; 0.001).

CONCLUSION

Four criteria including age (≥5 years), leukocytosis (≥10 000 cell/mm3), abdominal pain and watery diarrhea were identified as good predictors of Campylobacter enterocolitis. When three criteria were fulfilled, Campylobacter enterocolitis was highly suspected and antibiotic could be withheld even when C-reactive protein is high and before stool culture results are known. When four criteria were fulfilled, antibiotic usage was absolutely unnecessary.

Immunity to Campylobacter: its role in risk assessment and epidemiology

Acquired immunity is an important factor in the epidemiology of campylobacteriosis in the developing world, apparently limiting symptomatic infection to children of less than two years. However, also in developed countries the highest incidence is observed in children under five years and the majority of Campylobacter infections are asymptomatic, which may be related to the effects of immunity and/or the ingested doses. Not accounting for immunity in epidemiological studies may lead to biased results due to the misclassification of Campylobacter-exposed but apparently healthy persons as unexposed. In risk assessment studies, health risks may be overestimated when immunity is neglected.

Vaccination of chickens against Campylobacter

The gram-negative bacterium Campylobacter is the leading cause of bacterial entero-colitis in humans and is associated with the occurrence of life-threatening auto-immune based neurological disorders. Chickens, which are often heavily colonized with Campylobacter without signs of pathology, are considered the most important source for human infection. Although vaccination is a well established and effective method to combat various microbes in poultry, a commercial vaccine against Campylobacter has not yet been developed. For the development of such a vaccine, three main challenges can be identified: (1) the identification of novel cross-protection-inducing antigens, (2) the induction of a rapid, potent immune response, and (3) the development of novel adjuvants to further stimulate immunity against Campylobacter. The rapidly emerging knowledge of the biology of Campylobacter in combination with the recent advances in the fields of molecular vaccinology and immunology provide the required setting for the development of an effective vaccine against Campylobacter in poultry.

Temperature-driven Campylobacter seasonality in England and Wales

Campylobacter incidence in England and Wales between 1990 and 1999 was examined in conjunction with weather conditions. Over the 10-year interval, the average annual rate was determined to be 78.4 +/- 15.0 cases per 100,000, with an upward trend. Rates were higher in males than in females, regardless of age, and highest in children less than 5 years old. Major regional differences were detected, with the highest rates in Wales and the southwest and the lowest in the southeast. The disease displayed a seasonal pattern, and increased campylobacter rates were found to be correlated with temperature. The most marked seasonal effect was observed for children under the age of 5. The seasonal pattern of campylobacter infections indicated a linkage with environmental factors rather than food sources. Therefore, public health interventions should not be restricted to food-borne approaches, and the epidemiology of the seasonal peak in human campylobacter infections may best be understood through studies in young children.

Immune protection of human milk

Human milk contains a very large number of specific and non-specific immunologic and nonimmunologic factors who provide passive and active protection to the newborn. The immunologic factors are either immunostimulatory or immunosuppressive. The immunostimulatory ones increase host defense mechanisms mainly against infective illness, and the immunosuppressive ones downregulate inflammation and the development of allergies. Furthermore, human milk has been found to promote intestinal growth and maturation and to have immunomodulating effects beyond infancy, later on in life. In conclusion, human milk represents a very valuable weapon for enhancing the immature immunologic system of the newborn and for strengthening its deficient host defense mechanisms against infective or other foreign agents.

Antimicrobial factors and microbial contaminants in human milk: recent studies

An overview of recent studies of antimicrobial factors and microbial contaminants found in human milk is presented. The incidence of gastrointestinal and respiratory infections in infants receiving human milk continues to be lower than in those not breast-fed due to the presence of specific antibody and possibly anti-adhesion factors in the milk. Whether the many other antimicrobial factors, which have been shown to be active in vitro or in animal model systems, have any influence on infant infections is still not clear. Microbial contaminants in human milk are rare, as are associated infant infections from the milk. However, some contaminants such as cytomegalovirus are commonly transferred to infants from the milk of seropositive mothers, fortunately without any adverse effects in the infants. Human T-lymphotropic virus type 1 is transferred via human milk in endemic areas, human milk being the main source of mother-to-infant transmission. While some reports suggest human immunodeficiency virus type 1 transfer may occur through human milk, this is not the predominant mode of transmission to infants.

Immunoglobulin A antibodies directed against Campylobacter jejuni flagellin present in breast-milk

We studied the relationship between IgA anti-campylobacter flagellin antibodies in breast milk samples and protection of breastfed infants living in a rural Mexican village from campylobacter infection. There were fewer episodes of campylobacter infection (symptomatic and asymptomatic combined) in infants breastfed with milk containing specific anti-flagellin antibodies (1.2/child/year, 95% CI 0.6-1.8) versus non-breastfed children (3.3/child/year, 95% CI 1.8-4.8; P < 0.01). Infants breastfed with milk that was anti-flagellin antibody negative by ELISA also had fewer episodes of infection compared with non-breastfed children, but the difference did not reach statistical significance (1.8/child/year, 95% CI 0.7-3.0 versus 3.3/child/year, 95% CI 1.8-4.8, P > 0.05). Breastfeeding has a protective effect against campylobacter infection and is associated with the presence of specific antibodies directed against campylobacter flagellin.