Clinical Course of Children with Campylobacter Gastroenteritis With and Without Co-Infection in Lima, Peru

This study describes the clinical course of gastroenteritis caused by Campylobacter spp. as a single-infection versus coinfection and the corresponding changes that occur according to the treatment received, in children between 12 and 24 months of age. This descriptive study is based on the data of a pediatric cohort conducted between 2008 and 2011 of 555 children in Lima, Peru. Ninety-six diarrheal episodes with positive cultures for Campylobacter spp. were evaluated. In 52 episodes, empirical antibiotic treatment was started before pathogen isolation. Of these 96 episodes, 64.6% were coinfections with other pathogens. Coinfections were led by Escherichia coli, norovirus, and Giardia. Compared with single-infection episodes, coinfections had a mean symptom duration of 6.6 versus 5.7 days, a mean frequency of bowel movements per episode of 18.9 versus 14.8, and occurrence of vomiting and fever in 24.2% versus 14.7% of patients. Most of the patients with more severe clinical features at diagnosis were prescribed macrolides as empiric treatment. In the single-infection group, symptom duration was 7.2 ± 3.3 days in the macrolide-treated group and 7.9 ± 2.7 days in the nonmacrolide group. Diarrhea caused by coinfection appeared to be generally more severe than a single-pathogen. Patients with more severe clinical courses who received macrolides treatment might have had a faster recovery than patients who received nonmacrolides.

High Prevalence and Increased Severity of Norovirus Mixed Infections Among Children 12-24 Months of Age Living in the Suburban Areas of Lima, Peru

In an active diarrhea surveillance study of children aged 12-24 months in Lima, Peru, norovirus was the most common pathogen identified. The percentage of mixed (bacterial and noroviral) infections was significantly higher among norovirus-positive samples (53%) than among norovirus-negative samples (12%). The combination of norovirus with the most common bacterial pathogens was associated with increased clinical severity over that of either single-pathogen norovirus or single-pathogen bacterial infections.

Comparative analysis of antimicrobial resistance in enterotoxigenic Escherichia coli isolates from two paediatric cohort studies in Lima, Peru

BACKGROUND

Antibiotic resistance is increasing worldwide, being of special concern in low- and middle-income countries. The aim of this study was to determine the antimicrobial susceptibility and mechanisms of resistance in 205 enterotoxigenic Escherichia coli (ETEC) isolates from two cohort studies in children <24 months in Lima, Peru.

METHODS

ETEC were identified by an in-house multiplex real-time PCR. Susceptibility to 13 antimicrobial agents was tested by disk diffusion; mechanisms of resistance were evaluated by PCR.

RESULTS

ETEC isolates were resistant to ampicillin (64%), cotrimoxazole (52%), tetracycline (37%); 39% of the isolates were multidrug-resistant. Heat-stable toxin producing (ETEC-st) (48%) and heat-labile toxin producing ETEC (ETEC-lt) (40%) had higher rates of multidrug resistance than isolates producing both toxins (ETEC-lt-st) (21%), p<0.05. Only 10% of isolates were resistant to nalidixic acid and none to ciprofloxacin or cefotaxime. Ampicillin and sulfamethoxazole resistance were most often associated with blaTEM (69%) and sul2 genes (68%), respectively. Tetracycline resistance was associated with tet(A) (49%) and tet(B) (39%) genes. Azithromycin inhibitory diameters were ≤15 mm in 36% of isolates, with 5% of those presenting the mph(A) gene.

CONCLUSIONS

ETEC from Peruvian children are often resistant to older, inexpensive antibiotics, while remaining susceptible to ciprofloxacin, cephalosporins and furazolidone. Fluoroquinolones and azithromycin remain the drugs of choice for ETEC infections in Peru. However, further development of resistance should be closely monitored.

Rotavirus seasonal distribution and prevalence before and after the introduction of rotavirus vaccine in a peri-urban community of Lima, Peru

We evaluated the monthly distribution of rotavirus diarrhea in a cohort of children 12-24 months of age followed as part of a diarrhea clinical trial in a peri-urban community of Lima. We observed a peak of rotavirus diarrhea in the winter months and a decrease in rotavirus prevalence after the introduction of the rotavirus vaccine in Peru.

Randomized double-blind controlled trial of bovine lactoferrin for prevention of diarrhea in children

OBJECTIVE

To determine the effect of bovine lactoferrin (bLF) on prevention of diarrhea in children.

STUDY DESIGN

We conducted a community-based randomized double-blind placebo controlled trial comparing supplementation with bLF vs placebo. Previously weaned children were enrolled at 12-18 months and followed for 6 months with daily home visits for data collection and supplement administration. Anthropometric measures were done monthly.

RESULTS

Five hundred fifty-five children were randomized: 277 to bLF and 278 to placebo; 65 dropped out; 147 894 doses were administered (92% compliance). Overall there were 91 446 child-days of observation and 1235 diarrhea episodes lasting 6219 days. The main pathogens isolated during diarrheal episodes were norovirus (35.0%), enteropathogenic E coli (11.4%), Campylobacter (10.6%), enteroaggregative E coli (8.4%), enterotoxigenic E coli (6.9%), and Shigella (6.6%). The diarrhea incidence was not different between groups: 5.4 vs 5.2 episodes/child/year for bLF and placebo, respectively (P = .375). However, the diarrhea longitudinal prevalence was lower in the bLF group vs placebo (6.6% vs 7.0%, P = .017), as well as the median duration of episodes (4.8 vs 5.3 days, P = .046), proportion of episodes with moderate or severe dehydration (1.0% vs 2.6%, P = .045), and liquid stools load (95.0 vs 98.6) liquid stools/child/year, P < .001). There were no adverse events related to the intervention.

CONCLUSIONS

Although there was no decrease in diarrhea incidence, longitudinal prevalence and severity were decreased with LF.

Clinical studies of lactoferrin in children

Much has been learned in recent years about the mechanisms by which breastfeeding improves child health and survival. However, there has been little progress in using these insights to improve pediatric care. The aim of this study was to review all clinical studies of lactoferrin (LF) in children in an effort to determine which interventions may improve pediatric care or require further research. We conducted a systematic and critical review of published literature and found 19 clinical studies that have used human or bovine LF for different outcomes: iron metabolisms and anemia (6 studies), fecal flora (5 studies), enteric infections (3 studies), common pediatric illnesses (1 study), immunomodulation (3 studies), and neonatal sepsis (1 study). Although the efficacies have varied in each trial, the main finding of all published studies is the safety of the intervention. Protection against enteric infections and neonatal sepsis are the most likely biologically relevant activities of LF in children. Future studies on neonatal sepsis should answer critically important questions. If the data from these sepsis studies are proven to be correct, it will profoundly affect the treatment of low birth weight neonates and will aid in the reduction of child mortality worldwide.

Phylogenetic relationships of Shiga toxin-producing Escherichia coli isolated from Peruvian children

The aim of this study was to determine the prevalence, virulence factors (stx, eae, ehxA and astA) and phylogenetic relationships [PFGE and multilocus sequence typing (MLST)] of Shiga toxin-producing Escherichia coli (STEC) strains isolated from four previous cohort studies in 2212 Peruvian children aged <36 months. STEC prevalence was 0.4 % (14/3219) in diarrhoeal and 0.6 % (15/2695) in control samples. None of the infected children developed haemolytic uraemic syndrome (HUS) or other complications of STEC. stx1 was present in 83 % of strains, stx2 in 17 %, eae in 72 %, ehxA in 59 % and astA in 14 %. The most common serotype was O26 : H11 (14 %) and the most common seropathotype was B (45 %). The strains belonged mainly to phylogenetic group B1 (52 %). The distinct combinations of alleles across the seven MLST loci were used to define 13 sequence types among 19 STEC strains. PFGE typing of 20 STEC strains resulted in 19 pulsed-field patterns. Comparison of the patterns revealed 11 clusters (I-XI), each usually including strains belonging to different serotypes; one exception was cluster VI, which gathered exclusively seven strains of seropathotype B, clonal group enterohaemorrhagic E. coli (EHEC) 2 and phylogenetic group B1. In summary, STEC prevalence was low in Peruvian children with diarrhoea in the community setting. The strains were phylogenetically diverse and associated with mild infections. However, additional studies are needed in children with bloody diarrhoea and HUS.

Impact of lactoferrin supplementation on growth and prevalence of Giardia colonization in children

We conducted a randomized, double-blind, placebo-controlled trial comparing supplementation with bovine lactoferrin versus placebo for the prevention of diarrhea in children. Comparison of overall diarrhea incidence and prevalence rates found no significant difference between the 2 groups. However, there was a lower prevalence of colonization with Giardia species and better growth among children in the lactoferrin group.

Lactobacillus casei strain GG in the treatment of infants with acute watery diarrhea: a randomized, double-blind, placebo controlled clinical trial [ISRCTN67363048]

Background

Adjuvant therapy to ORT with probiotic bacteria for infants with acute watery diarrhea has been under active investigation. Most studies have been done in the developed world showing benefit only for viral mild gastroenteritis. We evaluated the effect of a milk formula containing one billion (10⁹) cfu/ml of Lactobacillus casei strain GG (LGG) upon duration and severity of diarrhea in infants in an environment with more severe acute diarrhea, where etiologic agents other than rotavirus are involved more frequently, and where mixed infections are more prevalent.

Methods

Male infants aged 3–36 months brought for treatment of acute watery diarrhea of less than 48 hours were eligible. After rehydration was completed with the WHO's oral rehydration solution, patients were randomly assigned to receive a milk formula either containing LGG or not. Stool volume was periodically measured using a devise suited to collect stools separate from urine. Duration of diarrhea was estimated based on stools physical characteristics.

Results

Eighty nine patients received the placebo milk formula and ninety received the LGG containing formula. Both groups were comparable in their baseline characteristics. Total stool output was significantly larger (p = 0.047) in the LGG group (247.8 ml/kg) than in the placebo group (195.0 ml/kg). No significant differences were found in duration of diarrhea (58.5 hours with LGG vs. 50.4 hours with placebo), rate of treatment failure (21.1% with LGG vs. 18.0% with placebo), and proportion of patients with unresolved diarrhea after 120 hours (12.2% with LGG vs. 12.5% with placebo). The rate of stools with reducing substances after 24 hours of treatment increased significantly in both groups (from 41.4% to 72.2% with LGG and from 45.9% to 68.0% with placebo).

Conclusion

This study did not show a positive effect of LGG on the clinical course of acute watery diarrhea. Positive beneficial effects of LGG, as had been reported elsewhere, could have been masked in our study by worsening diarrhea due to transient lactose malabsorption. Further studies with low-lactose or non-lactose conveyors of LGG are desirable.

Racecadotril in the treatment of acute watery diarrhea in children

BACKGROUND

Racecadotril (acetorphan), an enkephalinase inhibitor with antisecretory and antidiarrheal actions, is an effective and safe treatment for acute diarrhea in adults and children. Whether treatment with racecadotril and oral rehydration therapy is more effective than treatment with oral rehydration alone in hospitalized children with acute watery diarrhea is not known.

METHODS

We treated 135 boys 3 to 35 months of age who had watery diarrhea of five days' duration or less with racecadotril (1.5 mg per kilogram of body weight orally every eight hours) or placebo, in addition to oral rehydration solution. The primary end point was the 48-hour stool output (measured in grams); the total stool output, duration of diarrhea, and total intake of oral rehydration solution were also measured.

RESULTS

The mean (+/-SE) 48-hour stool output was 92+/-12 g per kilogram in the racecadotril group and 170+/-15 g per kilogram in the placebo group (P<0.001), a 46 percent reduction with racecadotril. The results were similar among the 73 boys with rotavirus infections. The total stool output was 157+/-27 g per kilogram in the racecadotril group and 331+/-39 g per kilogram in the placebo group (P<0.001). The median duration of diarrhea was significantly less (P<0.001) in the racecadotril group (28 hours regardless of rotavirus status) than in the placebo group (72 and 52 hours, respectively, for rotavirus-positive and rotavirus-negative patients). The intake of oral rehydration solution was significantly lower in the racecadotril group than in the placebo group (P<0.001). Racecadotril was well tolerated; only seven patients taking racecadotril had adverse effects, which were all mild and transient.

CONCLUSIONS

In young boys with acute watery diarrhea, racecadotril is an effective and safe treatment.

[The development of a clinical scale for the diagnosis of cholera in infants with acute watery diarrhea]

The diagnosis of cholera in infants based on clinical grounds is often difficult because other enteropathogens such as rotavirus or enterotoxigenic Escherichia coli (ETEC) can produced a very similar clinical picture. We studied 147 infants admitted consecutively to the Rehydration Unit of Cayetano Heredia Hospital in Lima, Perú, trying to identified those characteristics significantly associated with the isolation of Vibrio cholerae 01 on the admission stool culture. After a univariate comparison of cases and controls were selected those characteristics that showed a significantly different distribution. These were entered in a logistic regression model to analyze their interactions. After this analysis four variables remain significantly associated to cases: no history of fever, dehydration greater than 7%, fecal pH greater than 7 and no glucose in feces. Were developed a diagnostic score with these variables, which had a sensitivity of 77.6% and a specificity of 73.6%. It is important to prospectively validate the utility of this score.

Evaluation of alkaline phosphatase-labelled ipaH probe for diagnosis of Shigella infections

The presence of many enteropathogens which are not easily detectable by routine stool culture has led to the development of alternative diagnostic methods. One of these techniques, nucleic acid probe hybridization, has been used to identify Shigella spp. and enteroinvasive Escherichia coli (EIEC) in stool specimens through the detection of genetic material encoded by a specific large approximately 200-kbp virulence-related plasmid. In the present study, an alkaline phosphatase-labelled oligonucleotide probe developed to detect the gene for ipaH, a repetitive genetic sequence thought to be present on both the virulence-related plasmid and the chromosomes of all strains of Shigella and EIEC, was tested in a developing-country setting through a prospective clinical trial. In a group of 219 Peruvian adults and children with acute gastroenteritis, the ipaH probe detected 85% of cases of shigellosis and demonstrated a specificity of 95% when compared with simultaneous detection by several stool culture techniques. Additionally, three cases of EIEC infection which could not be diagnosed by culture methods alone were detected with the ipaH probe and were confirmed by plasmid analysis and Sereny testing. These preliminary results suggest that, with further research, the ipaH probe should prove to be a useful and rapid adjunct in the diagnosis of acute gastroenteritis in developing countries.

Evaluation of clinical management training programme for diarrhoea

We report the evaluation of a training programme on clinical management of infantile diarrhoea. The training programme was delivered through a series of on-site clinical courses offered to a selected group of physicians and nurses from 16 health units in Peru and a series of local workshops conducted in their own health units. The outcome of this training programme was assessed by pre- and post-tests, knowledge, attitude, and practice (KAP) questionnaires, and observational surveys. A significant improvement in medical knowledge about diarrhoea, in particular about the use of ORT and drug therapy, was observed. Although the observational surveys showed significant improvement in the use of ORT at health facilities (2.9% to 23.6%, p = 0.007) the rate observed was still low compared to the high level of knowledge on ORT that was demonstrated by the KAP questionnaires. A reduction of antibiotic prescription for inpatients with diarrhoea (85.7% to 64.8%, p = 0.025) was observed. The training programme was also effective in promoting the establishment of Oral Rehydration Units in the participants' health facilities.

Early treatment with erythromycin of Campylobacter jejuni-associated dysentery in children

To evaluate the efficacy of early treatment with erythromycin on the duration of fecal excretion and of diarrhea associated with Campylobacter jejuni, 170 patients, age 3 to 60 months, were randomly assigned in a double-blind fashion to receive either erythromycin ethyl succinate or placebo immediately after being seen at Cayetano Heredia Hospital because of acute dysentery. The groups' pretreatment characteristics were comparable. Of the 30 patients with stools positive for C. jejuni, 12 were in the placebo group and 16 in the treatment group. After 2 days of treatment, none of the patients in the placebo group and 36% of those in the erythromycin group had normal stools (P less than 0.05). After 5 days of treatment, 50% of the patients in the placebo group and 93% of those in the erythromycin group had normal stools (P less than 0.02). Fecal excretion of the organism continued significantly longer in the placebo group (P less than 0.01). There were no treatment failures in the treatment group compared with five (42%) in the placebo group (P less than 0.01). Thus, early administration of erythromycin significantly reduced the duration of both diarrhea and fecal excretion of the organism in infants and children with acute dysentery associated with C. jejuni.

Bicarbonate versus citrate in oral rehydration therapy in infants with watery diarrhea: a controlled clinical trial

In a double-blind, randomized trial, we compared the efficacy of bicarbonate-containing oral rehydration solution vs citrate-containing solution in the treatment of infantile diarrheal dehydration and acidosis. Ninety-seven infants 3 to 24 months of age were entered in the study; 49 received bicarbonate-containing solution and 48 citrate-containing solution. The two groups were similar in all respects at the beginning of the study. Oral rehydration was successful (i.e., no intravenously administered fluids were required) in 85% of study patients; the success rate was similar in both treatment groups. Serum total CO2 concentration increased in a similar fashion in both groups, reaching near normal values at 48 hours after admission. We conclude that sodium citrate can be substituted for sodium bicarbonate in the formulation of the orally administered rehydration solution recommended by the World Health Organization for treatment of diarrheal dehydration in infants.