Showing papers in "Pediatric Infectious Disease Journal in 1989"

Effect of neuropeptides on production of inflammatory cytokines by human monocytes

Abstract: Two groups of mediators, the neuropeptides substance P and K and the monocyte-derived cytokines, interact in the neural regulation of immunological and inflammatory responses. Substance P, substance K, and the carboxyl-terminal peptide SP(4-11) induce the release of interleukin-1, tumor necrosis factor-alpha, and interleukin-6 from human blood monocytes. The neuropeptide effects occur at low doses, are specific as shown by inhibition studies with a substance P antagonist, and require de novo protein synthesis. Since monocyte-derived cytokines regulate multiple cellular functions in inflammation and immunity and since neuropeptides can be released from peripheral nerve endings into surrounding tissues, these findings identify a potent mechanism for nervous system regulation of host defense responses.

Dexamethasone treatment for bacterial meningitis in children and adults.

Abstract: Four hundred twenty-nine patients with bacterial meningitis were assigned on a nonselective alternating basis into one of two therapeutic regimens. Patients in Group I received dexamethasone in addition to standard antibacterial chemotherapy of ampicillin and chloramphenicol whereas those in Group II received antibacterial chemotherapy alone. Dexamethasone was given intramuscularly (8 mg to children younger than 12 years and 12 mg to adults every 12 hours for 3 days). Both treatment groups were comparable with regard to age, sex, duration of symptoms and state of consciousness at the time of hospitalization. A significant reduction in the case fatality rate (P less than 0.01) was observed in patients with pneumococcal meningitis receiving dexamethasone; only 7 of 52 patients died compared with 22 of 54 patients not receiving dexamethasone. A reduction in the overall neurologic sequelae (hearing impairment and paresis) was observed in patients receiving dexamethasone. This reduction was significant only in patients with Streptococcus pneumoniae meningitis; none of the 45 surviving patients receiving steroids had hearing loss whereas 4 of 32 patients not receiving dexamethasone had severe hearing loss (P less than 0.05). No significant difference was observed between the two groups with regard to time for patients to become afebrile or to regain consciousness or in the mean admission and 24- to 36-hour cerebrospinal fluid leukocyte count, glucose or protein content.

Acute otitis media and respiratory virus infections.

Abstract: We studied the association of acute otitis media with different respiratory virus infections in a pediatric department on the basis of epidemics between 1980 and 1985. Altogether 4524 cases of acute otitis media were diagnosed. The diagnosis was confirmed by tympanocentesis in 3332 ears. Respiratory virus infection was diagnosed during the same period in 989 patients by detecting viral antigen in nasopharyngeal mucus. There was a significant correlation between acute otitis media and respiratory virus epidemics, especially respiratory syncytial virus epidemics. There was no significant correlation between outbreaks of other respiratory viruses and acute otitis media. Acute otitis media was diagnosed in 57% of respiratory syncytial virus, 35% of influenza A virus, 33% of parainfluenza type 3 virus, 30% of adenovirus, 28% of parainfluenza type 1 virus, 18% of influenza B virus and 10% of parainfluenza type 2 virus infections. These observations show a clear association of respiratory virus infections with acute otitis media. In this study on hospitalized children Haemophilus influenzae strains were the most common bacteriologic pathogens in middle ear fluid, occurring in 19% of cases. Streptococcus pneumoniae was present in 16% and Branhamella catarrhalis in 7% of cases. There was no association between specific viruses and bacteria observed in this study.

Epidemiologic study of 4684 hospital-acquired infections in pediatric patients.

Abstract: During a 4-year period 4684 nosocomial infections occurred in a university pediatric hospital which admitted 78,120 patients (nosocomial infection rate (NIR) = 6.0). NIR varied from 0.17 to 14.0 on different wards or services; the highest rates (greater than or equal to 5.6) were found in the Neonatal Intensive Care Unit, infant neurosurgery, hematology/oncology, neonatal surgery, cardiology/cardiovascular surgery, Pediatric Intensive Care Unit and infant/toddler medicine areas. Infections were most common in patients less than or equal to 23 months (NIR = 11.5), were less common in the 2- to 4-year age group (NIR = 3.6) and occurred least frequently in patients greater than or equal to 5 years (NIR = 2.6). The median day of onset of infections was 15.3 days. The proportional frequencies of infections were: 35% gastrointestinal; 21% bacteremia; 16% respiratory (10% upper, 6% lower); 7% postoperative wound; 6% urinary tract; 5% skin (32% of these skin infections were related to intravascular lines); 5% eye; 3% cerebrospinal fluid; and 2% other. A similar proportional frequency of 379 infections in patients hospitalized for more than 100 days was observed. The etiologic agents were Gram-positive bacteria (50%), viruses (23%), Gram-negative bacteria (18%), fungi (4%) and mixed/other (5%).

Problems in determining the etiology of community-acquired childhood pneumonia.

Abstract: Fifty-seven children ages 1 month to 12 years hospitalized because of community-acquired pneumonia were compared with age-matched controls who had acute asthma without pneumonia to test the value of rapid bacterial antigen detection and clinical and radiographic criteria for diagnosis of bacterial pneumonia. Bacterial pneumonia, defined on the basis of positive cultures of blood or pleural fluid, was diagnosed in 4 children (7%), 1 of whom also had viral pneumonia. Viral pneumonia, defined as a positive nasopharyngeal sample or positive serology, was diagnosed in 20 children (35%). Serum and concentrated urine were tested by latex agglutination (Wellcogen) for Haemophilus influenzae type b and pneumococcal antigens and by countercurrent immunoelectrophoresis for pneumococcal antigens. Pneumococcal antigen could not be detected in serum or urine from 3 children with culture-proved pneumococcal pneumonia, indicating poor sensitivity of the tests. In contrast apparent H. influenzae type b antigenuria was detected by latex agglutination in 4 of 40 children with pneumonia but also in 5 of 57 controls, and a sensitive enzyme-linked immunosorbent assay for polyribosyl ribitol (PRP) phosphate antigen showed that all 9 cases were false positives. The specificity of H. influenzae type b antigen detection was thus poor. Children with viral and bacterial pneumonia could not be distinguished by radiographic or clinical criteria (symptoms, fever) or by total or differential white blood cell counts, serum C-reactive protein or nasal or serum interferon levels. It is not possible to distinguish reliably childhood viral from bacterial pneumonia clinically or by rapid diagnostic tests.

Etiology of community-acquired pneumonia in children based on antibody responses to bacterial and viral antigens.

Abstract: The serologic responses to bacterial and viral antigens were determined in paired serum samples from 336 children, ages 1 month to 15 years, with roentgenographically verified community-acquired pneumonia. Significant increases in antibodies against one agent were found in 40% and against two or more agents in 8% of the children. There were significant increases in antibodies against respiratory syncytial virus in 20%, viruses of the influenza-parainfluenza group in 6% and adenovirus in 3%. A serologic response to one or more of the pneumococcal antigens used (type-specific capsular polysaccharide, C-polysaccharide and pneumolysin) was demonstrated in 13% of the patients. Ten percent of the children had significant increases in antibodies against Mycoplasma pneumoniae. Only three patients had increases against Haemophilus influenzae type b and one each against Legionella pneumophila and Chlamydia. Respiratory syncytial virus was the predominant etiologic agent in young children whereas M. pneumoniae was more frequent in the older age group.

The impact of otitis media.

Abstract: Otitis media is one of the most worldwide prevalent diseases that affects children. The socioeconomic costs may exceed 3.5 billion dollars a year in the United States alone in direct and indirect costs. If a vaccine can be developed that will decrease 1% of the illness this would be significant in this country and probably even more valuable in less developed countries.

Outcome of treatment of candidemia in children whose central catheters were removed or retained.

Abstract: In this study we reviewed the outcomes of all pediatric patients at Duke University Medical Center between 1978 and 1987 who were treated with amphotericin B and in whom Candida sp. fungemia occurred in the presence of a venous or arterial central catheter. Twenty-one episodes were evaluated for efficacy of either of 2 interventions. In 13 patients the catheter was removed and amphotericin B therapy was begun (Group 1), and in 8 patients, the catheter was retained and amphotericin B therapy was begun (Group 2). Persistent candidemia beyond onset of intervention occurred in 2 of the 13 patients in Group 1 and in 6 of the 8 patients in Group 2 (P = 0.018). In Group 1, 2 of the 13 patients subsequently developed new complications of candidiasis, and no patient died of causes related to candidiasis. In Group 2, 3 of the 8 patients had resolution of persistent candidemia only after catheter removal, 3 developed new complications of candidiasis after initiation of amphotericin B and 2 died with systemic candidal infection. Only one of the catheters initially retained was maintained successfully beyond the second week of amphotericin B therapy. We conclude that adverse outcomes (persistent fungemia, morbidity and mortality) are associated with attempts to maintain central catheters in the presence of candidemia.

Bacterial coinfection in children hospitalized with respiratory syncytial virus infections

Abstract: Clinical and bacterial findings were prospectively studied in 90 children hospitalized because of middle or lower respiratory tract infection caused by respiratory syncytial virus (RSV) during a surveillance period of 12 months. The results were compared with those of RSV-negative children hospitalized with identical indications during the 3 peak months of the RSV epidemic (N = 91) or for the 3 months after the outbreak (N = 99). A high frequency of pneumonia and acute otitis media were found in both RSV-positive and RSV-negative children during the epidemic, but not in control patients after the epidemic. Bacterial infection, based on a significant rise of antibody titer and/or on detection of pneumococcal antigen in serum or urine, was observed in 39% of the children with RSV infection. The respective figures were 24% in RSV-negative children hospitalized during the epidemic and 8% after the epidemic. Our observations stress the role of RSV as a predisposing agent for secondary bacterial infection in the airways of children. The most common bacteria involved in the mixed RSV-bacterial infections were Streptococcus pneumoniae and Haemophilus influenzae, the latter being found only in pneumonic patients. The presence or absence of pneumonia or acute otitis media was not significantly correlated with evidence of pneumococcal infection. We conclude that a bacterial pathogen should be actively sought when managing patients with lower respiratory tract syndromes, especially in those who have evidence of RSV infection.

Seronegative lyme disease: dissociation of specific t and b lymphocyte responses to borrelia burgdorferi

Abstract: The diagnosis of Lyme disease often depends on the measurement of serum antibodies to Borrelia burgdorferi, the spirochete that causes this disorder. Although prompt treatment with antibiotics may abrogate the antibody response to the infection, symptoms persist in some patients. We studied 17 patients who had presented with acute Lyme disease and received prompt treatment with oral antibiotics, but in whom chronic Lyme disease subsequently developed. Although these patients had clinically active disease, none had diagnostic levels of antibodies to B. burgdorferi on either a standard enzyme-linked immunosorbent assay or immunofluorescence assay. On Western blot analysis, the level of immunoglobulin reactivity against B. burgdorferi in serum from these patients was no greater than that in serum from normal controls. The patients had a vigorous T-cell proliferative response to whole B. burgdorferi, with a mean ( +/- SEM) stimulation index of 17.8 +/- 3.3, similar to that (15.8 +/- 3.2) in 18 patients with chronic Lyme disease who had detectable antibodies. The T-cell response of both groups was greater than that of a control group of healthy subjects (3.1 +/- 0.5; P less than 0.001). We conclude that the presence of chronic Lyme disease cannot be excluded by the absence of antibodies against B. burgdorferi and that a specific T-cell blastogenic response to B. burgdorferi is evidence of infection in seronegative patients with clinical indications of chronic Lyme disease.

Outbreak of poliomyelitis-like paralysis associated with enterovirus 71.

Abstract: In the summer of 1987 five children were seen at The Children's Hospital of Philadelphia because of acute onset of flaccid paralysis of an arm or leg(s). Although there were documented exposures to oral poliovirus vaccine and coxsackievirus B3 in some of the cases, the clinical, epidemiologic and la

A multicenter therapeutic study of 1100 children with brucellosis.

Abstract: A 6-year multicenter therapeutic study was performed on 1100 children with brucellosis in order to compare several antibiotic combinations and duration of treatment The patients were randomized to receive oral therapy with oxytetracycline, doxycycline, rifampin and trimethoprim-sulfamethoxazole (TMP/SMX) either alone or in combination with each other or combined with streptomycin or gentamicin injections The patients were also randomized into three groups based on the duration of oral therapy: 500 patients were treated for 3 weeks; 350 for 5 weeks; and 250 for 8 weeks When intramuscular aminoglycosides were used, streptomycin was given for 2 weeks and gentamicin for 5 days In oral monotherapy oxytetracycline, doxycycline and rifampin showed comparable results with low relapse rates (less than or equal to 9%) and no statistically significant differences were found among 3-, 5- or 8-week durations of therapy TMP/SMX alone showed an unacceptably high relapse rate (30%) with all durations of therapy In combined oral therapy rifampin plus oxytetracycline, rifampin plus TMP/SMX and oxytetracycline plus TMP/SMX showed comparable results with low relapse rates ranging from 4 to 8% in patients receiving therapy for 3 or 5 weeks, no relapses occurred in patients treated for 8 weeks When oral monotherapy was combined with either streptomycin or gentamicin, very few relapses were seen, irrespective of the duration of treatment(ABSTRACT TRUNCATED AT 250 WORDS)

Meningococcal infections in children: a review of 100 cases.

Abstract: One hundred children with meningococcal infection diagnosed from January 1, 1985, to February 29, 1988, were reviewed. Clinical manifestations ranged from fever alone to fulminant septic shock with purpura fulminans. Twenty-nine percent of the children presented without skin lesions. Of the 55 patients with meningitis, 6 lacked cerebrospinal fluid abnormalities on initial lumbar puncture but cerebrospinal fluid cultures were positive. An overall case fatality rate of 10% was noted with the following poor prognostic indicators identified: hypothermia; seizures or shock on presentation; a total peripheral white blood cell count less than 5000/mm3; a platelet count less than 100,000/mm3; and the development of purpura fulminans. Meningococcal infections remain an important cause of morbidity and mortality in children. Infections caused by Neisseria meningitidis (including meningitis) should be considered even in the absence of skin lesions or cerebrospinal fluid abnormalities.

Varicella-zoster virus infections in children infected with human immunodeficiency virus

Abstract: Primary varicella-zoster (VZ) infection in eight children with perinatally acquired human immunodeficiency virus infection tended to be severe, prolonged, complicated by bacterial infections and in one case fatal. Depletion of CD4-lymphocytes was associated with chronic and recurrent VZ infection. I

Epidemiology of invasive Haemophilus influenzae type b disease among children in Finland before vaccination with Haemophilus influenzae type b conjugate vaccine.

Abstract: On the basis of intensified surveillance in Finland we report the epidemiology of invasive Haemophilus influenzae type b disease based on 333 consecutive culture-proved cases recorded during 1985 and 1986. The annual incidence rate among children younger than 5 years of age was 52/100,000; 46% of patients had meningitis, 29% had epiglottitis and 25% had other forms of invasive disease. The median age of patients was 27 months, with 45% younger than 2 years of age. Meningitis and epiglottitis were found more often among boys than among girls, whereas the opposite was found among patients with other types of invasive disease (P = 0.015). Among the latter 68% of children with pneumonia or septicemia were 2 years or older compared with 32% of patients with arthritis, cellulitis or pyelonephritis (P = 0.009). These background data are essential for correct interpretation and application of results from trials with H. influenzae type b conjugate vaccines that are currently ongoing in Finland.

Enteroaggregative Escherichia coli and Salmonella associated with nondysenteric persistent diarrhea

Abstract: A hospital-based case-control study including 92 children with diarrhea for longer than 14 days and 92 controls without gastrointestinal symptoms was performed to describe the association between the excretion of enteric pathogens and persistent diarrhea. In patients the most frequently isolated stool pathogens were enteroaggregative Escherichia coli (19.6%), nontyphoidal Salmonella spp. (17.4%), E. coli with diffuse adherence pattern (7.6%), G. lamblia (7.6%) and enterotoxigenic E. coli (5.4%). The excretion rates in patients were significantly greater than in controls only for nontyphoidal Salmonella spp. (P = 0.0006) and enteroaggregative E. coli (P = 0.016).

Duration of hospitalization in previously well infants with respiratory syncytial virus infection

Abstract: To describe the typical hospital course of infection in previously well infants hospitalized with respiratory syncytial virus (RSV) infection, we reviewed the charts of 196 patients with laboratory-proved respiratory syncytial virus infection in the 1987-1988 respiratory disease season. Eighty-seven of the children had been previously well. Their mean duration of hospitalization was 3.4 days. Previously well infants younger than 6 weeks of age experienced significantly longer hospitalizations and more days of supplemental oxygen and were more likely to require intensive care than were older children. Children older than 12 weeks of age were hospitalized for a mean of 2.5 days and did not require intensive care. Oxygen saturation was measured in the emergency room for 67 of the previously well infants; in 42 oxygen saturation was at least 90% whereas in 25 saturation was less than 90% or infants were receiving supplemental oxygen at the time of measurement. Decreased initial oxygen saturation was associated with a prolonged hospitalization (5.3 vs. 3.2 days, P less than 0.01) and with more days of supplemental oxygen (4.4 vs. 1.5 days, P less than 0.01). We conclude that among previously well infants admitted to the hospital with respiratory syncytial virus infection, infants younger than 6 weeks of age are at increased risk for a prolonged and more severe hospital course than are older children.

Clinical presentation of Bacillus Calmette-Guérin infections in patients with immunodeficiency syndromes.

Abstract: Nine children with immunodeficiency syndromes who developed persistent or disseminated Bacillus Calmette-Guerin (BCG) infections after BCG vaccination at birth were observed in Santiago, Chile, over a period of 10 years This represents a risk for persistent or disseminated BCG infections of 34/1,000,000 vaccinated newborns This may closely reflect the incidence of severe combined immunodeficiency syndromes, cellular immunodeficiency syndromes and chronic granulomatous disease in the study area The clinical presentation and course of the infection varied considerably depending on the underlying immunodeficiency syndrome Two patients with severe combined immunodeficiency presented with cutaneous nodules in the absence of any local reaction at the site of BCG vaccination Both patients died of disseminated BCG infection within the first year of life Four patients with cellular immunodeficiency syndromes presented with regional lymphadenitis resistant to treatment after the fifth month of life Three of these patients had specific unresponsiveness to tuberculin and survived from 5 to 6 years of age Two boys with X-linked chronic granulomatous disease presented with regional lymphadenitis in the first 3 months of life A girl with autosomal recessive chronic granulomatous disease presented at 18 months of age with regional lymphadenitis All three patients with chronic granulomatous disease had positive tuberculin reactions and died from infections other than BCG

Clinical signs that predict death in children with severe pneumonia.

Abstract: It is important to define clinical signs that can be used to identify children who have a high risk of dying from pneumonia so that these children can be given more intensive therapy. We prospectively studied 748 children in Papua New Guinea who had severe pneumonia, as defined by the World Health O

Brain abscess in infants and children

Abstract: Y. Er~ahin (~) 9 S. Mutluer 9 E, Giizelba~ Division of Pediatric Neurosurgery, Department of Neurosurgery, Ege University Medical School, Bornova, TR-35100 Izmir, Turkey Abstraet Forty-four consecutive patients with brain abscesses, aged between 1 month and 16 years, were reviewed. The cause of abscess was meningitis in 36% of the cases, otitis in 27%, head injury in 16%, congenital heart disease in 9%, other in 5%, and undetected in 5%. Thirty patients had a single abscess and 12 had multiple abscesses. Multiloculated abscess was present in 2. Total excision was accomplished in 22 patients. Three patients underwent needle aspiration. Drainage of the abscess was performed in 13. Secondary excision was needed in 5 patients. One patient was treated nonsurgically. Streptococci, staphylococci and Proteus mirabilis were the microorganisms recovered in cultures. Overall mortality was 20% (9 patients). Mortality was significantly higher in patients under 2 years of age than in those older. Of 15 patients who were comatose at the time of admission, 6 died. Etiology, diagnostic method, and treatment modalities were not found to be significant factors in terms of predicting mortality.

Trends in mortality in children hospitalized with meningococcal infections, 1957 to 1987.

Abstract: We reviewed charts of 261 children seen at Children's Hospital of Wisconsin from 1957 to 1987 with culture-proven meningococcemia or meningococcal meningitis, and we analyzed trends in mortality and disease severity for that interval. Overall case fatality was 10%, ranging from 9% in the period 1957 to 1963, to 16% in the period 1980 to 1987 (P = 0.15). The percent of patients admitted with severe disease increased from 14% to 38% (P = 0.001). When stratified by disease severity, case-fatality rates did not change with time. We conclude that technologic advances of the past 30 years had no measurable impact on mortality from meningococcal infection in our hospital and that crude case-fatality rates can be misleading if disease severity is not considered.

Human parvovirus B19 infections in women of childbearing age and within families

Abstract: Human parvovirus B19 (B19) crosses the placenta causing fetal death. We used an indirect capture enzyme immunoassay to measure IgG to B19 in sera of 845 subjects from 2 groups. The first group included 405 women (mean age, 30 years) composed of 85 pediatric nurses and 130 other female hospital employees, 122 women employed caring for preschool children and 68 mothers of preschool children enrolled in day care. Twenty-eight percent of all these women were seropositive. Seropositivity was unrelated to occupational group. Four of 235 women observed between 1983 and 1987 for a mean of 435 days/woman acquired B19 infections (an annual seroconversion rate of 1.5%). We investigated intrafamilial associations of B19 infection in a second group of 440 subjects from 111 families. Seropositivity of parents was not associated with seropositivity of their children. Seropositivity of one spouse was not associated with seropositivity of the cospouse. However, of 47 seropositive older siblings, 32 (68%) of their younger siblings were seropositive, compared to 20 (18%) seropositive younger siblings of 112 seronegative older siblings (P less than 0.001). B19 infections increased with age from 19% for those younger than 10 years to 67% for those older than 49 years. For all ages females had a higher rate (51%) of B19 infection than males (38%). These data suggest that children may be more susceptible to B19 than adults and B19 infections occur infrequently among women younger than 40 years of age. However, during local outbreaks the B19 infection rate for susceptible pregnant women remains unknown.

Cerebrospinal fluid interleukin 1-beta and tumor necrosis factor concentrations and outcome from neonatal gram-negative enteric bacillary meningitis.

Abstract: Concentrations of interleukin 1-beta and tumor necrosis factor in cerebrospinal fluid (CSF) of 42 neonates with Gram-negative enteric bacillary meningitis were determined and correlated with outcome and other CSF indices. At the time of diagnosis interleukin 1-beta was detected in CSF of 40 infants and peak concentrations correlated significantly with outcome from disease. Days of interleukin 1-beta concentrations of greater than 200 pg/ml or greater than or equal to 20 pg/ml were significantly correlated with days that CSF cultures were positive and that K1 antigen and endotoxin were detected in CSF. Tumor necrosis factor activity was detected in CSF of 25 of 27 infants; there was no correlation between outcome and CSF tumor necrosis factor concentrations. The results provide a possible rationale for therapeutic intervention to improve outcome.

Prognosis of human immunodeficiency virus infection in children and adolescents.

Abstract: The prognosis of 111 children and adolescents (from 2.5 months to 19.5 years of age) infected with human immunodeficiency virus (HIV) was assessed by survival analysis based on risk factors and clinical status. Risk factors included: maternal HIV infection 93; transfusion 12; both maternal HIV infection and transfusion 2; sexual abuse 1; and intravenous drug use and/or sexual activity 3. Children with perinatal infection survived from 2.5 months to 10.25 years (median, 1.87 years) and had inapparent infection from 6 weeks to 7.3 years (median, 0.75 years). Children who acquired HIV infection via transfusion had inapparent infection from 4 months to 5.7 years (median, 3.6 years). Actuarial survival following infection was not significantly different from maternally and transfusion-acquired infection; however, survival from infection was longer for children infected by transfusion beyond 2 years of age (mean, 7.5 years) than for children infected perinatally (mean, 5.6 years). The case-fatality ratio was 32%, with 25% of subjects succumbing within 1 year of developing an HIV-associated illness. Opportunistic infection was the most common acquired immunodeficiency syndrome-defining illness and the cause of death in 22 of the 35 children who died. Pneumocystis carinii and fungal pneumonias had the worst prognosis. Cryptosporidiosis and other opportunistic infections had a better prognosis. Because of difficulties in case finding, diagnosis of infection and variable survival of HIV-infected children, arge longitudinal studies and pooling of data among centers will be necessary to have an accurate understanding of the prognosis of individual clinical syndromes.(ABSTRACT TRUNCATED AT 250 WORDS)

Asymptomatic giardiasis in children.

Abstract: Giardia lamblia infection was identified in 33 of 89 (37%) 3-month-old to 3-yr-old children who were followed with monthly stool examinations for up to 12 months in a day care center. The infection was mainly asymptomatic and usually associated with prolonged carriage of the parasite. There were no significant differences for height and weight achievements and mean hemoglobin values between Giardia-positive and Giardia-negative children. However, Giardia-positive children tended to achieve higher weight and height for age than Giardia-negative children; weight for age was above the 50th percentile in 69% of Giardia-positive vs. 40% of Giardia-negative children (alpha = 0.01). Giardia-positive children tended to have fewer symptoms related to the gastrointestinal and respiratory tracts as recorded by a weekly questionnaire. Lactase deficiency was detected by breath hydrogen testing in 8 of 26 Giardia-positive vs. only 1 of 21 Giardia-negative children (P less than 0.02). Healthy day care children with asymptomatic Giardia infection show no disadvantage and perhaps even an advantage in nutritional status and freedom from other illnesses.