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Biomedical subjects

L K Pickering

Publications and source records attributed to L K Pickering.

At least 91 records · Page 5Linked to original sources
PubMed1991

Knowledge and attitudes of day care center parents and care providers regarding children infected with human immunodeficiency virus.

It was hypothesized that parents and child care providers are not prepared to accept children infected with human immunodeficiency virus (HIV), who are increasing in number, into the day care center setting. To determine their knowledge and attitudes toward HIV transmission, 219 parents in 4 day care centers and 176 care providers in 12 day care centers were given confidential questionnaires. More than 98% of respondents knew that sex and needle sharing can transmit HIV; 84% of parents and 77% of care providers knew that contact with blood can transmit HIV. There was, however, uncertainty about transmission via many common contacts in day care centers: human bites, urine, stool, tears, and vomit; kissing; sharing of food and eating utensils; and diaper changing areas. Only 43% of parents said they would allow their child to stay in the same room with a child who was infected with HIV. In a multiple logistic regression model, the unwillingness of parents to have their child stay in the same room with a child who was infected with HIV was significantly (P less than .0001) associated with black ethnicity, beliefs that such a child is likely to infect others (40%) and is dangerous to others (58%), and fear of their child being exposed to HIV (86%). Care providers' unwillingness to care for a child infected with HIV in the classroom (48%) was significantly (P less than .0001) associated with beliefs that such a child is likely to infect others (44%) and that common day care center contacts can transmit HIV (62%).(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1990

Invasive disease due to multiply resistant Streptococcus pneumoniae in a Houston, Tex, day-care center.

Two toddlers who attended the same day-care center were hospitalized hours apart with sepsis and meningitis due to a multiply resistant Streptococcus pneumoniae. We determined the prevalence of multiply resistant S pneumoniae respiratory carriage and disease in infants, toddlers, and staff in the day-care center and in household contacts. The nasopharynges of 82 (96%) of 85 day-care center children, 26 (90%) of 29 day-care center staff, and 28 (90%) of 31 family members were cultured. Streptococcus pneumoniae grew from 29 (35%) of the 82 cultured day-care center children. Ten (34%) of the S pneumoniae isolates were resistant to sulfamethoxazole-trimethoprim, oxacillin, and tetracycline and were relatively resistant to penicillin (minimum inhibitory concentration, 0.5 mg/L). All were serotype 14 and had the same antibiotic resistance pattern. Treatment of 97% of the day-care center children and staff with rifampin (10 mg/kg twice daily for 2 days) resulted in 70% reduction in positive nasopharyngeal cultures for S pneumoniae. No additional disease due to multiply resistant S pneumoniae was identified in the day-care center during a 9-month follow-up period. This report documents that an outbreak of multiply resistant invasive S pneumoniae occurred in a day-care center setting; that nasopharyngeal colonization of exposed children was common; and that rifampin treatment of 2 days only partially eradicated the organism from colonized individuals.

Administration, Oral↗
PubMed1990

Protection of breast-fed infants against Campylobacter diarrhea by antibodies in human milk.

To investigate the role of breast-feeding in preventing diarrhea caused by Campylobacter jejuni, we followed 98 Mexican children prospectively for 2 years beginning at their birth. Attack rates of diarrhea in children less than 6 months of age who were not fed human milk were 2.3 times greater than those in children of the same age who were fed human milk. Breast-fed children remained free of diarrhea for a longer time than non-breast-fed children (p less than 0.0005). The diarrhea attack rate caused by C. jejuni for non-breast-fed infants was significantly greater (p less than 0.005) than that in the breast-fed group. Secretory IgA milk antibody titers against glycine acid-extractable antigen of C. jejuni were high in colostrum, decreased during the first month of breast-feeding, and generally persisted throughout lactation. Human milk consumed by children in whom Campylobacter diarrhea developed did not contain secretory IgA antibodies to the glycine acid-extractable common antigen of Campylobacter. This study shows an association between Campylobacter antibodies in human milk and prevention of diarrhea caused by Campylobacter.

Antibodies, Bacterial↗
PubMed1990

The association of Shiga toxin and other cytotoxins with the neurologic manifestations of shigellosis.

The neurologic symptoms in human shigellosis have often been attributed to Shiga toxin, although its exact role has not been determined. By use of a [3H] thymidine-labeled HeLa cell assay, cytotoxic activity was demonstrated in stool but not cerebrospinal fluid or serum from five patients with shigellosis presenting with seizures or encephalopathy. Bacterial isolates produced 16.0-88.2 CD50 (50% cytotoxic dose) of cytotoxin/mg of protein. The toxin activity in stool and the cytotoxic activity of the isolates were not neutralized by antiserum to purified Shiga toxin. DNA hybridization studies showed that Shigella isolates from these patients lacked the structural genes for Shiga toxin. The cytotoxin produced was also distinct from Shiga-like toxins I and II. Sonicates of the Shigella strains injected intraperitoneally into mice caused lethargy and lethality. The toxin activity was heat-labile and sensitive to trypsin, indicating that its active component is protein. Ultrafiltration and gel filtration chromatography showed a molecular mass of 100-125 kDa. Thus Shiga toxin production is not essential for the development of neurologic manifestations of shigellosis; other toxic products may play a role.

Animals↗
PubMed1990

Molecular epidemiology of rotavirus in children attending day care centers in Houston.

Serotype distribution of group A rotavirus in children attending day care centers has not been previously reported. Fifteen centers in Houston participated in longitudinal monitoring of rotavirus infection during one to three consecutive rotavirus seasons. Monitoring included daily recording of the presence of diarrhea and weekly stool collection. Stool specimens containing rotavirus were analyzed by a monoclonal antibody (MAb)-based ELISA specific for the VP7 protein of serotypes 1, 2, 3, and 4 and by gel electrophoresis. A total of 318 children had 362 rotavirus episodes; 149 could be serotyped. Serotype distribution of this population was similar to that of children hospitalized for diarrhea in a large pediatric hospital in Houston during the same period. Symptomatic infections were predominantly due to serotype 1 rotaviruses in season 2 and serotype 3 rotaviruses in season 3. Episodes recurred in 43 children; 2 children had second symptomatic infections of the same serotype as the first. Electrophoretic differences among rotaviruses of a same serotype were common and more frequent among serotype 1 than serotype 3 viruses.

Age Factors↗
PubMed1990

Fucosylated oligosaccharides of human milk protect suckling mice from heat-stabile enterotoxin of Escherichia coli.

Human milk protects suckling mice from the diarrheagenic effects of heat-stabile enterotoxin of Escherichia coli (ST). To identify the human milk fraction responsible for this protection, pooled skimmed, deproteinated milk was passed through charcoal, whereupon lactose was separated from the oligosaccharides. The oligosaccharides contained ST-protective activity; the lactose did not. The neutral, but not the acidic, fraction exhibited protective activity against ST (22% vs. 57% mortality, respectively; P less than .001). The fucosylated, but not the nonfucosylated, subfractions of the neutral fraction contained the factor protective against ST (35% vs. 50% mortality, respectively; P less than .05). An oligosaccharide isolation scheme based on different principles produced confirmatory results. The commercially available neutral fucosylated oligosaccharides of human milk did not significantly protect the mice from the effects of ST. Thus, the protective factor against ST seems to be a minor neutral fucosyloligosaccharide of human milk.

Animals↗
PubMed1990

Longitudinal study of Giardia lamblia infection in a day care center population.

An enzyme-linked immunosorbent assay was used to detect Giardia lamblia in stool specimens collected during a 15-month longitudinal study of diarrhea in 82 children 1 to 24 months old attending a day care center (DCC) in Houston. A total of 2727 stool specimens were collected on a weekly basis from the DCC children and were evaluated for rotavirus and Giardia. For DCC children who developed diarrhea stool specimens were also cultured for bacterial enteropathogens. During the 15-month study period, 48 episodes of Giardia infection were detected in 27 of 82 (33%) DCC children, compared with 57 episodes of rotavirus detected in 37 (45%) of these same DCC children. The duration of Giardia excretion was 2.0 +/- 1.5 weeks (mean +/- SD). Only 6 (7%) of the 82 DCC children, or 6 of the 27 (22%) with infection, developed symptoms attributable to Giardia. Ten of the 27 (37%) DCC children infected with Giardia had 2 or more episodes of infection. Giardia was identified in the DCC in all months except June. Two Giardia outbreaks occurred in 1 of the 6 DCC rooms under study. One outbreak was associated with overcrowding. Neither outbreak was associated with the introduction of a new Giardia-positive child into the involved room. In this study Giardia infection occurred commonly in the DCC throughout the year, was rarely associated with illness and was not associated with introduction of asymptomatic carriers into the DCC rooms.

Child Day Care Centers↗
PubMed1990

Asymptomatic human calicivirus infection in a day care center.

Human caliciviruses (HCVs) are little known, recently recognized viruses associated with gastroenteritis. We identified HCV infection in an outbreak of gastroenteritis which occurred in one room of a day care center (DCC) participating in a longitudinal study of diarrhea. Utilizing an enzyme-linked immunoassay and immunosorbent electron microscopy to detect HCV, we tested specimens from all children in attendance during the period of the illness outbreak and during prior and subsequent weeks. HCV infection was documented in 14 children, 11 of whom were asymptomatic. Thirteen of the 14 HCV-infected children were 8 months of age or younger. New cases of HCV infection occurred during a 4-week period. Forty percent of children less than 1 year of age were infected with HCV during the period of investigation. Few documented HCV infections have been reported. This may be related to a high attack rate of predominantly asymptomatic infections in early life, resulting in a high prevalence of antibody to HCV by 4 years of age.

Caliciviridae↗
PubMed1990

Comparative in vitro activities of amoxicillin-clavulanic acid, cefuroxime, cephalexin, and cephalothin against trimethoprim-resistant Escherichia coli isolated from stools of children attending day-care centers.

A high prevalence of fecal colonization with trimethoprim-resistant Escherichia coli was found in diapered children attending day-care centers in Houston, Tex. In the present study, 100 isolates of E. coli resistant to multiple antibiotics, including trimethoprim (100%), sulfisoxazole (100%), streptomycin (94%), and ampicillin (87%), were obtained over a 5-month period from stool samples of diapered children attending four day-care centers and tested for their susceptibilities to amoxicillin-clavulanic acid, cefuroxime, cephalexin, and cephalothin. The MICs for 50 and 90% of strains tested were 16 and 32 micrograms/ml, respectively, for amoxicillin-clavulanic acid, 4 and 16 micrograms/ml, respectively, for cefuroxime, 4 and 64 micrograms/ml, respectively, for cephalexin, and 32 and greater than 64 micrograms/ml, respectively, for cephalothin. Although all three oral beta-lactams tested were generally active at concentrations likely to be achieved in urine, cefuroxime and cephalexin were more potent and are thus more likely to be inhibitory at the concentrations needed for systemic infections.

Amoxicillin↗
PubMed1990

Risk factors for fecal colonization with trimethoprim-resistant and multiresistant Escherichia coli among children in day-care centers in Houston, Texas.

In a previous study, we found fecal colonization with multiresistant Escherichia coli exhibiting high-level trimethoprim resistance in 19% of diapered children attending six day-care centers in Houston, Tex. To examine the potential risk factors associated with this finding, we conducted cross-sectional studies among 203 children attending 12 day-care centers, 51 children attending a well-child clinic (controls), and 64 medical students. The prevalence of fecal colonization with trimethoprim-resistant E. coli among children attending day-care centers (30%) was higher (P less than 0.001) than among control children (6%) or medical students (8%). The prevalence of colonization among the children attending the 12 centers ranged from 0 to 59% and was correlated with the number of diapered children enrolled (r = 0.73; P less than 0.01). In a case control study among the day-care center children, significant risk factors were an age of less than 12 months and attendance at a center with an enrollment of over 40 diapered children (odds ratios of 2.2 and 3.5, respectively); ethnicity, duration of attendance, and prior antibiotic administration were not associated with colonization. Plasmid analysis of 60 of the day-care center strains revealed 22 profiles, each of which was unique to a given day-care center. Transmission and carriage of trimethoprim-resistant strains for as long as 6 months was documented in one center studied on three occasions. Given the documented transmission of enteric pathogens among diapered children attending day-care centers and their spread into family members, it is likely that day-care centers are an important community reservoir of plasmid-associated antibiotic-resistant E. coli.

Adolescent↗
PubMed1990

Infections in child day care centers as they relate to internal medicine.

Internists should be aware of the increased frequency of most communicable diseases among parents and child care providers exposed to children attending child day care centers. Episodes of shigellosis and hepatitis A among adults in contact with children in day care centers should be promptly reported to public health authorities, since they may indicate the presence of a day care center outbreak for which effective control measures are available. Although effective treatment or intervention is limited or not available for many other infections acquired by adults from children in day care centers, significant illness may result in a minority of individuals at increased risk for infection with agents such as cytomegalovirus and varicella. Acute infectious diseases of children caused by organisms transmitted from day care center staff are less common and largely preventable by ensuring that staff are appropriately immunized and screened for tuberculosis.

Adult↗
PubMed1989

Rapid detection of giardia antigen in stool with the use of enzyme immunoassays.

Enzyme-linked immunosorbent assays (ELISAs) using sera from rabbits and goats immunized with Giardia trophozoites were compared for detection of Giardia antigen in 300 stool specimens, 80 of which had positive results for Giardia by microscopic examination. The diagnostic accuracy of the two assays was similar, with sensitivities of 92% and 87% and specificities of 87% and 91% with the use of rabbit and goat antisera, respectively. Both ELISAs detected Giardia antigen in stool samples from asymptomatic as well as symptomatic excretors and from treated patients after organisms were no longer visualized by microscopic examination. The specificity of the assays was confirmed by consistently negative results on stool specimens from 10 neonates and 27 patients with enteric parasitic infections other than Giardia. Negative results also occurred when stool specimens containing 21 bacterial enteropathogens were tested. Potential confounding variables including multiple freezing and thawing episodes, prolonged storage, and stool filtration did not affect test results from clinical specimens. Antidiarrheal compounds did not interfere with assay results. Preservation of specimens in formalin did interfere with the assay, even if formalinized stool specimens were dialyzed before testing. For diagnosis of giardiasis, the ELISA is a sensitive and specific test that is not influenced by many environmental factors or by other enteropathogens. This test provides a practical and reliable method for evaluating large numbers of specimens in a variety of clinical and epidemiologic settings.

Animals↗