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Biomedical subjects

W J Rodriguez

Publications and source records attributed to W J Rodriguez.

At least 91 records · Page 5Linked to original sources
PubMed1981

Comparison of direct electron microscopy, immune electron microscopy, and rotavirus enzyme-linked immunosorbent assay for detection of gastroenteritis viruses in children.

An approximate 10% suspension in water of the first available stool sample from 411 infants and young children with acute gastroenteritis was examined by electron microscopy (EM) after 2 min of negative staining. This procedure enabled the detection of 88% of the 199 rotavirus infections, all of the 22 adenovirus infections, and 47% of the 15 approximately 27-nm virus infections ultimately detected by a combination of techniques, including immune electron microscopy (IEM) and rotavirus enzyme-linked immunosorbent assay (ELISA). Of the 204 infections detected by direct EM of stools, 76% were detected within 2 min of viewing, and 94% were detected within 6 min of viewing. Type 1 and type 2 rotavirus particles were visualized with approximately equal efficiency, although type 2 rotavirus infections were more common. Rectal swab preparations were clearly inferior to stool preparations for the detection of virus infection by direct EM. IEM examination was required for efficient visualization of viruses in rectal swab specimens. ELISA was the most sensitive method for the detection of rotaviruses; with this method, all infections in which rotavirus particles were visualized by EM or IEM were detected. However, 73% of the 1,834 specimens which were presumptively positive for rotavirus by conventional indirect ELISA proved to be falsely positive on the basis of EM, IEM, blocking ELISA, confirmatory ELISA, or a combination of these methods. False-positive rotavirus ELISA reactions apparently were eliminated when fecal specimens were tested in a modified confirmatory ELISA with a lower dilution of rotavirus-negative (pre-immunization) than rotavirus-positive (post-immunization) capture antibody from the same animal.

Acute Disease↗
PubMed1981

Ampicillin-resistant Hemophilus influenzae type B septic arthritis in children.

Three cases of ampicillin-resistant Hemophilus influenzae type B septic arthritis are described. These patients presented over a four-month period (November 1978 to February 1979). All were less than 18 months of age, all had positive blood and joint aspirate cultures, and counter-current immunoelectrophoresis (CIE) on serum positive for Hemophilus influenzae type B. The ampicillin minimum inhibitory concentration (MIC) for all three isolates was 6.25 microgram/ml or greater. All patients recovered uneventfully with intravenous chloramphenicol therapy. We suggest that chloramphenicol be considered in the initial therapy of children under 18 months of age who present with septic arthritis, at least in geographic areas where the incidence of ampicillin resistance is high.

Ampicillin↗
PubMed1981

Persistent purulent otitis media.

Of 429 children with acute otitis media who returned for follow-up evaluation, 49 (11%) were unresponsive to a 10- to 14-day course of ampicillin, amoxicillin, or erythromycin/sulfisoxazole. Patients with persistent purulent otitis media were noted to have immobile, bulging, yellow or grey, abscessed tympanic membranes at the follow-up visit. A myringotomy was performed on 45 children. Cultures of middle-ear exudate yielded ampicillin-resistant Haemophilus influenzae in 14 (31%), ampicillin-susceptible pathogens (H. influenzae or Streptococcus pneumoniae) in 23 (51%), and no growth in 8 (18%).

Acute Disease↗
PubMed1981

Acute otitis media: toward a more precise definition.

Eighty-five infants and children presenting with acute otitis media who had normal tympanic membrane landmarks and mobility within 1 month before entry into the study were studied. These criteria were used in order to avoid including children with prior otitis media with effusion (secretory otitis media). A diagnosis of suppurative otitis media was made in each case based on pneumo-otoscopic findings of diminished mobility, contour, and color of the tympanic membrane. The diagnosis was validated by myringotomy and positive culture of the middle ear fluid. A poorly mobile, bulging, yellow, opacified tympanic membrane was the most common type of tympanic membrane visualized; whereas a poorly mobile, bulging, red tympanic membrane was seen in ony 19%. The color of the tympanic membrane did not correlate with a specific pathogen isolated from the middle ear exudate. Sixty-seven per cent of children had no fever; 28% had no pain or querulous behavior.

Acute Disease↗
PubMed1981

Office myringotomy for acute otitis media: its value in preventing middle ear effusion.

Middle ear effusion (MEE) as a residual of treated acute otitis media was found in 49% of 776 children studied. No antibiotic singly or in combination, demonstrated superiority in reducing the incidence of MEE. Simple myringotomy, as a therapeutic modality in 415 children who presented with an acutely bulging painful eardrum, did not facilitate adequate drainage as 51% of such children, treated with simple myringotomy in addition to antibiotics, had MEE detected 10 days later. The incidence of MEE also occurred independently of the middle ear pathogen. Within six weeks, spontaneous resolution of the effusion occurred in 85% of the 382 children with MEE that was detected 10 days after acute otitis media.

Acute Disease↗
PubMed1980

Aerobic and anaerobic bacteriology of pilonidal cyst abscess in children.

Aspirates of pus from pilonidal abscesses in 25 children were studied for aerobic and anaerobic bacteria. A total of 76 isolates (63 anaerobic and 13 aerobic) were recovered from the patients, accounting for 2.52 anaerobes and 0.52 aerobes per specimen. Anaerobic organisms were recovered from all the specimens, and in eight cases (32%) they were mixed with aerobic organisms. The predominant anaerobic organisms were Bacteroides sp (36 isolates, including ten B fragilis group and ten B melaninogenicus group), Gram-positive anaerobic cocci (16). Fusobacterium sp (five), and Clostridium sp (four). The predominant aerobic organisms were Escherichia coli (four) and group D streptococci, alpha-hemolytic streptococci, and Proteus sp (two of each). We believe this study is the first to demonstrate the mixed anaerobic and aerobic bacteriology of pilonidal cyst abscesses in children.

Abscess↗
PubMed1980

Rotavirus gastroenteritis in the Washington, DC, area: incidence of cases resulting in admission to the hospital.

The incidence of rotavirus gastroenteritis in infants and children that required admission to the hospital was estimated for a defined population of approximately 105,000 individuals, including 29,000 children aged 15 years or younger whose primary health care was provided by Group Health Association, Inc, a health maintenance organization in the Washington, DC, area. From January 1977 through March 1979, almost all infants and children in this age group who required hospitalization for gastroenteritis were studied for evidence of infection with human rotavirus (HRV) and other agents. On the average, one in 272 (3.7/1,000) infants less than 12 months old and one in 451 (2.2/1,000) children aged 13 through 24 months were hospitalized for HRV disease each winter. The incidence of rotavirus gastroenteritis requiring hospitalization declined precipitously in children after the second birthday and such illness was not detected in children aged 5 years or older. The role of other agents in acute gastroenteritis requring hospitalization was minimal, compared with that of rotavirus.

Adolescent↗
PubMed1980

Anaerobic bacteremia in children.

Twenty-nine anaerobic isolates were recovered from 28 pediatric patients with anaerobic bacteremia: 14 Bacteroides sp (11 in the B fragilis group); four anaerobic Gram-positive cocci; four Clostridium sp; four Propionibacterium acnes; and three Fusobacterium sp. No aerobic bacteria were isolated from these patients. The gastrointestinal tract was the possible portal of entry in 13 instances, eight of which were due to Bacteroides organisms, four to Clostridium sp, and one to F nucleatum. The ear, sinus, and oropharynx were probable portals of entry in seven instances, four of which were due to Peptococcus sp and two to Fusobacterium sp. Five patients (18%) died; four had bacteremia caused by B fragilis group, and one had bacteremia caused by P acnes. The average duration of antimicrobial therapy was 20 days (range, seven to 72 days). The early recognition and rapid institution of appropriate antimicrobial and surgical therapy are of utmost importance in improving the outcome of these patients.

Adolescent↗
PubMed1980

Meningitis in typhoid fever: an unusual complication.

A case of Salmonella typhi meningitis in a 15-month-old child was manifested only by organisms in the CSF, emphasizing the need for spinal tap in children with typhoid fever. The infection responded satisfactorily to special drug therapy.

Female↗
PubMed1980

Gonococcal scalp abscess in a newborn.

We have described a 6-day-old male infant who presented with Neisseria gonorrhoeae conjunctivitis and a scalp abscess. Delivery was complicated by rupture of the membranes 24 hours before delivery and fetal monitoring for four hours. The rare scalp abscesses caused by gonococci cleared with penicillin therapy.

Abscess↗
PubMed1980

Draining ears in acute otitis media: reliability of culture.

The purulent exudates in the ear canal of 69 children who presented with acute otorrhea were cultured directly onto standard media. No effort was made to either suction out the exudate lying in the canal or to use antiseptic agents on the canal wall. Potential pathogens such as H. influenzae, S. pneumoniae and S. pyogenous were recovered from two-thirds of the patients who suffered spontaneous otorrhea. Reliable cultures can be obtained from such patients provided the cultures are plated expeditiously on solid agar.

Acute Disease↗
PubMed1980

Complications of sinusitis in children.

Eight patients (6 to 15 years of age) who had periorbital cellulitis and other complications of sinusitis were studied. Both ethmoid and maxillary sinusitis were present in four patients, frontal sinusitis in two, and ethmoid sinusitis and pansinusitis in one patient each. Subdural empyema occurred in four patients, in one case accompanied by cerebritis and brain abscess and in another by meningitis. Periorbital abscess was present in two children who had ethmoiditis. Alveolar abscess in the upper incisors was present in two children whose infection had spread to the maxillary and ethmoid sinuses. Anaerobic bacteria were isolated from the infected sinuses in all the patients. These were seven isolates of Bacteroides sp, four Fusobacterium sp, three microaerophilic streptococci, three Gram-positive anaerobic cocci, and two Veillonella sp. There was only one aerobic isolate recovered, a group F beta-hemolytic. Streptococcus. Surgical drainage and appropriate antimicrobial therapy resulted in complete eradication of the infection in all patients. The role of anaerobic bacteria in sinus infection and its subsequent complication is discussed. Given the possible serious complications of this disease, the early recognition of sinusitis in children and the institution of appropriate antimicrobial and surgical therapy are of great clinical importance.

Abscess↗
PubMed1979

The nasopharyngeal culture in acute otitis media. A reappraisal of its usefulness.

Simultaneous cultures of the nasopharynx and middle ear exudate (obtained by tympanocentesis) were obtained from 225 children (mean age, 34 months; median age, 41 months) with suppurative otitis media. A 72% prediction rate for middle ear pathogens was obtained by examining the nasopharyngeal cultures after the strict observance of two essential prerequisites: (1) the nasopharyngeal culture was immediately plated on appropriate solid agar and (2) a semiquantitative method for bacterial enumeration was employed in the reading of the nasopharyngeal culture plates. The technique was most valuable where 2+ (greater than 25% up to 50% of total number of colonies was a single pathogen) or greater of a single pathogen was recovered from the nasopharynx. In only one instance, the semiquantitative nasopharyngeal culture incorrectly predicted the middle ear pathogen if one was recovered. Quantitative nasopharyngeal cultures were particularly useful in predicting the presence of ampicillin-resistant Haemophilus influenzae and group A streptococci as causative agents in otitis media.

Acute Disease↗
PubMed1979

Common exposure outbreak of gastroenteritis due to type 2 rotavirus with high secondary attack rate within families.

A sharp outbreak of gastroenteritis associated with human rotavirus type 2 involved not only all of nine infants and young children in a playgroup but also seven of 10 parents and grandparents studied. The source of the outbreak appeared to be two non-playgroup siblings. Six of 11 individuals studied shed human rotavirus type 2, and each of seven from whom paired sera were obtained developed a type 2 sero-response. Overall, evidence of infection with rotavirus type 2 was demonstrated in 10 of 11 individuals by detection of virus in stools and/or a serologic response in an enzyme-linked immunosorbent assay.

Antibodies, Viral↗
PubMed1979

Comparative epidemiology of two rotavirus serotypes and other viral agents associated with pediatric gastroenteritis.

Human rotavirus (HRV) type 1 or 2, adenovirus, or non-cultivatable 27 nm virus-like particles were demonstrated by electron microscopy and/or rotavirus ELISA in fecal samples from 45.5% of 604 gastroenteritis inpatients, 25.0% of 200 gastroenteritis outpatients and 6.0% of 812 control subjects, all sampled at Children's Hospital National Medical Center. Washington, DC. Rotaviruses were the most common pathogens detected as 39% and 22% of gastroenteritis inpatients and outpatients, respectively, shed HRV. About three-fourths of the rotaviruses were type 2, which was prevalent during five successive epidemic years from January, 1974, through June, 1978. HRV type 1 was detected in the last four successive epidemic years and represented nearly half of the HRV infections observed among gastroenteritis inpatients during the year 1977--1978. Both rotavirus serotypes were detected most often in the month of January, when 71% of 123 gastroenteritis inpatients and 62% of 34 gastroenteritis outpatients shed one of these viruses. Uncultivatable adenoviruses were detected significantly more frequently in stools from patients with gastroenteritis (3.9%) than from control subjects (0.6%), suggesting that these viruses played a role in acute enteric disease. The frequency of detection of 27 nm particles was not significantly different in gastroenteritis and control patients. Numerically, HRV infection was detected most often in gastroenteritis inpatients who were 10 through 12 months of age. The group of gastroenteritis inpatients with the highest percentage of HRV infection was 13 through 15 months of age. The excess of type 2 HRV infection relative to type 1 infection was especially large in those aged 7 through 24 months. Lower socioeconomic status or greater crowding appeared to be associated with the occurrence of rotavirus infection earlier in life and earlier in the epidemic year.

Adenoviridae↗