PubMed Health⌕ Search

Biomedical subjects

M C Steinhoff

Publications and source records attributed to M C Steinhoff.

At least 19 recordsLinked to original sources
PubMed2006

Animal models for protein pneumococcal vaccine evaluation: a summary.

This paper summarizes the discussion and viewpoints from a recent meeting regarding the use of animal models for pneumococcal protein vaccines. A wide spectrum of workers in this field met to discuss the animal species to be used in models, the approach of passive and active protection, the characteristics of challenge pneumococcal strains, inducing disease syndromes by a variety of routes of challenge, the determination of specific endpoints to assess effectiveness, the correlates of protection and other details of experimental design and analysis. Vaccine regulatory aspects were discussed. The document concludes with a series of questions that remain to be investigated.

Animals↗
PubMed2005

Evaluation of the WHO clinical decision rule for streptococcal pharyngitis.

AIMS: To prospectively assess the WHO clinical decision rule (CDR) for group A beta haemolytic streptococcal (GABHS) pharyngitis in three countries. METHODS: A prospective, observational cohort study in urban outpatient clinics in Rio de Janeiro, Cairo, and Zagreb. There were 2225 children aged 2-12 years with cough, rhinorrhoea, red or sore throat; 1810 of these with sore throat were included in the analysis. RESULTS: The proportion of children presenting with sore throat and found to have GABHS pharyngitis ranged from 24.6% (Brazil) to 42.0% (Croatia). WHO CDR sensitivity was low for all sites in both age groups. In children age 5 or older, sensitivity ranged from 3.8% in Egypt to 10.8% in Brazil. In children under 5, sensitivity was low (0.0-4.6%) Specificity was high in both age groups in all countries (93.8-97.4%). CONCLUSIONS: In these populations, the current WHO CDR has high specificity, but low sensitivity; it did not detect up to 96.0% of children who have laboratory confirmed GABHS pharyngitis. A CDR with higher sensitivity should be developed for use in regions where rheumatic fever and rheumatic heart disease are still major health problems.

Brazil↗
PubMed2003

Comparison of different culture media and storage temperatures for the long-term preservation of Streptococcus pneumoniae in the tropics.

OBJECTIVE: The preservation of Streptococcus pneumoniae by standard freezing methods for subsequent tests--such as serotyping and antibiotic susceptibility--is not possible or is difficult in many developing countries because of the high cost of equipment, inadequate equipment maintenance, and irregular power supply. We evaluated alternative low-cost methods, by comparing different culture media and storage temperatures. METHODS: Clinical isolates of five capsular types (1, 5, 7, 19, and 23) of S. pneumoniae were preserved in rabbit blood, sheep blood, skimmed milk, or glycerol-chocolate broth, and stored at -20 degrees C or -70 degrees C. The cultures were also preserved by lyophilization or sand desiccation, followed by storage at room temperature and 4 degrees C. The viability of the preserved cultures was determined by making serial colony counts on day 0 and after 1 week, 4 weeks, 4 months and 16 months. The viability of cultures preserved by sand desiccation and storage at 4 degrees C was also determined every 6 months for up to 68 months. FINDINGS: Irrespective of the media used, cultures maintained at -20 degrees C became nonviable by the fourth month, while those maintained at -70 degrees C were still viable at 16 months. Cultures preserved by lyophilization or sand desiccation lost their viability by the fourth month when maintained at local room temperature (30-42 degrees C), but remained viable when stored at 4 degrees C for up to 68 months. CONCLUSIONS: Our results confirm that freezing at -70 degrees C, or lyophilization and storage at 4 degrees C are the ideal methods for the preservation of S. pneumoniae. In laboratories where lyophilization is not feasible, sand desiccation and storage at 4 degrees C offers an alternative low-cost method for the long-term preservation of S. pneumoniae.

Cell Culture Techniques↗
PubMed2001

Antipneumolysin antibody titers in HIV-seropositive injection drug users before and after pneumococcal bacteremia.

Lower baseline antipneumolysin antibody (alpha-PLY) levels have been found in populations with a higher incidence of pneumococcal infections. To determine whether predisease alpha-PLY titer is associated with invasive pneumococcal disease in HIV-seropositive injection drug users (IDU), we utilized a prospective cohort of IDU in Baltimore to compare alpha-PLY titers before bacteremia in 28 HIV- seropositive IDU cases with alpha-PLY titers in 56 matched (CD4 and seroconversion date) HIV-seropositive IDU control subjects and 28 matched (calendar time) HIV-seronegative IDU control subjects remaining free of pneumococcal disease. We also compared the postinfection fold-rise of alpha-PLY titers in cases relative to the change in alpha-PLY titers in control subjects during the same interval; alpha-PLY titers were measured using quantitative ELISA, and functional activity was assessed using antihemolysin assays. Predisease alpha-PLY titer did not differ between cases (66 units) and HIV-seropositive control subjects (70 units, p = 0.56) or HIV-seronegative control subjects (80 units, p = 0.10). There was a significant difference in fold-rise of alpha-PLY titers postdisease between cases (1.18) and HIV-seronegative control subjects (0.76), p = 0.03. Baseline alpha-PLY titers do not differ significantly between HIV-seropositive IDU who develop pneumococcal bacteremia from HIV-seropositive and HIV-seronegative IDU control subjects remaining free of severe pneumococcal disease.

Adolescent↗
PubMed2000

Persistent rhinorrhoea in rural Indian children: prevalence and consequences.

To determine whether persistent rhinorrhoea constitutes a significant problem requiring intervention, 17 rural day care centres (Balwadis) in Tamilnadu, India, were visited. Among 414 children in the Balwadis 92 (22 per cent) children with persistent rhinorrhoea (15 days duration or longer) were identified. Demographic and clinical data and nasopharyngeal swabs for bacterial culture were obtained from 56 such children and 91 age-matched controls from the same Balwadi. Type of housing or nutritional status did not appear to be significant risk factors. There was a significantly higher number of children aged 5-15 years in the household of cases as compared to controls (1.23 +/- 1.08 vs. 0.83 +/- 0.95, p = 0.02). Other illnesses were noted in 25 (44.6 per cent) cases and seven (7.7 per cent) controls (OR 11.5; CI, 4.13-33.4; p < 0.00001). Notably, chronic ear discharge was noted in 6 (11.7 per cent) cases but in none of the controls (p = 0.007). Streptococcus pneumoniae was isolated from nasopharyngeal swabs in 42/49 (85.7 per cent) cases and 44/80 (55 per cent) controls (p < 0.001) and H. influenzae from seven cases and five controls; S. pneumoniae was isolated in all children with chronic ear discharge and H. influenzae from one child. Serotypes of pneumococci commonly associated with otitis media, i.e., types 6, 14, 19, and 23 were isolated from 25 (51 per cent) cases and 16 (20 per cent) controls (OR 4.17; 95% CI, 1.78-9.85; p < 0.001). Persistent rhinorrhoea, presumably due to pneumococcus, is a common condition among rural Indian children and appears to be associated with chronic otitis media.

Adolescent↗
PubMed2000

Extensive swelling after booster doses of acellular pertussis-tetanus-diphtheria vaccines.

BACKGROUND: Diphtheria and tetanus toxoid combined with acellular pertussis (DTaP) vaccines are less reactogenic than diphtheria and tetanus toxoid combined with whole cell pertussis (DTwP) vaccines. However, local reactions increase in rate and severity with each successive DTaP dose, and swelling of the entire injected limb has been reported after booster doses. METHODS: We reviewed reports of swelling of the entire thigh or upper arm after the fourth and fifth dose, respectively, of DTaP vaccines administered in the National Institutes of Health multicenter comparative DTaP studies. Relationships were explored among reports of severe swelling, rates of other reactions, quantity of vaccine contents, and prevaccination and postvaccination antibody levels to pertussis toxin, tetanus toxin, and diphtheria toxin. RESULTS: Entire thigh swelling was an unsolicited reaction reported in 20 (2%) of the 1015 children who received 4 consecutive doses of the same DTaP vaccine. The reaction was associated with 9 of the 12 DTaP vaccines evaluated. Although there were no reports of swelling of the entire upper arm in 121 children given a fifth dose of the same DTaP, 4 (2.7%) of 146 recipients of 5 doses of a mixed schedule of DTaP vaccines experienced such swelling. Rates of other reactions were higher in children with entire thigh swelling than in those without. Of the children with entire thigh swelling, 60% had local pain, and 60% had erythema. All swelling subsided spontaneously without sequelae. There was a significant linear association between the rates of entire thigh swelling after dose 4 and diphtheria toxoid content in the DTaP products. Lesser degrees of swelling (>50 mm but less than entire limb) correlated with pertussis toxoid content after dose 4 and aluminum content after dose 5. No relationship was established between levels of serum antibody to diphtheria, tetanus, or pertussis toxin and rates of swelling of the whole thigh. CONCLUSIONS: Booster doses of DTaP vaccines can cause entire limb swelling, which is usually associated with redness and pain. Our data suggest that this extensive swelling reaction may be more common with vaccines containing high diphtheria toxoid content.

Antibodies, Bacterial↗
PubMed2000

Age- and cause-specific childhood mortality in Lombok, Indonesia, as a factor for determining the appropriateness of introducing Haemophilus influenzae type b and pneumococcal vaccines.

Using age and cause-specific childhood mortality in Lombok, Indonesia, as a factor for determining the appropriateness of introducing Haemophilus influenzae type b (Hib) and pneumococcal vaccines, the study describes a cross-sectional, hamlet-level mortality survey in 40 of 305 villages in Lombok Island, Indonesia. Causes of death were assessed with a standardized verbal-autopsy questionnaire. One thousand four hundred ninety-nine births and 141 deaths occurring among children aged less than 2 years were identified, with 43% of deaths occurring during the first 2 months of life. The infant mortality rate was 89 (95% CI: 75, 104) per 1,000 live-births. All mortality rates are reported per 1,000 live-births. To examine children whose deaths could potentially have been prevented through vaccination with Hib or pneumococcal vaccine, deaths due to acute respiratory infection (ARI) and central nervous system (CNS) infections among children, aged 2-23 months, were analyzed. ARI and CNS infections caused 58% (mortality rate: 31 per 1,000 live-births; 95% CI: 23, 41) and 17% (mortality rate: 9 per 1,000 live-births; 95% CI: 5, 16), respectively, of all deaths within this age group. Between the ages of 2 and 23 months, 5% of all babies born alive died of ARI, and another 1% died of CNS infections. Our results indicate that current efforts to reduce childhood mortality should focus on reducing ARI and meningitis. These efforts should include evaluating the impact of Hib and pneumococcal vaccines within the routine Expanded Programme on Immunization system.

Age Factors↗
PubMed1999

Effectiveness of influenza vaccine in health care professionals: a randomized trial.

CONTEXT: Data are limited and conflicting regarding the effectiveness of influenza vaccine in health care professionals. OBJECTIVE: To determine the effectiveness of trivalent influenza vaccine in reducing infection, illness, and absence from work in young, healthy health care professionals. DESIGN: Randomized, prospective, double-blind, controlled trial over 3 consecutive years, from 1992-1993 to 1994-1995. SETTING: Two large teaching hospitals in Baltimore, Md. PARTICIPANTS: Two hundred sixty-four hospital-based health care professionals without chronic medical problems were recruited; 49 participated for 2 seasons; 24 participated for 3 seasons. The mean age was 28.4 years, 75% were resident physicians, and 57% were women. INTERVENTION: Participants were randomly assigned to receive either an influenza vaccine or a control (meningococcal vaccine, pneumococcal vaccine, or placebo). Serum samples for antibody assays were collected at the time of vaccination, 1 month after vaccination, and at the end of the influenza season. Active weekly surveillance for illness was conducted during each influenza epidemic period. MAIN OUTCOME MEASURES: Serologically defined influenza infection (4-fold increase in hemagglutination-inhibiting antibodies), days of febrile respiratory illness, and days absent from work. RESULTS: We conducted 359 person-winters of serologic surveillance (99.4% follow-up) and 4746 person-weeks of illness surveillance (100% follow-up). Twenty-four(13.4%) of 179 control subjects and 3 (1.7%) of 180 influenza vaccine recipients had serologic evidence of influenza type A or B infection during the study period. Vaccine efficacy against serologically defined infection was 88% for influenza A (95% confidence interval [CI], 47%-97%; P=.001) and 89% for influenza B (95% CI, 14%-99%; P=.03). Among influenza vaccinees, cumulative days of reported febrile respiratory illness were 28.7 per 100 subjects compared with 40.6 per 100 subjects in controls (P=.57) and days of absence were 9.9 per 100 subjects vs 21.1 per 100 subjects in controls (P=.41). CONCLUSIONS: Influenza vaccine is effective in preventing infection by influenza A and B in health care professionals and may reduce reported days of work absence and febrile respiratory illness. These data support a policy of annual influenza vaccination of health care professionals.

Absenteeism↗
PubMed1999

Nasopharyngeal colonization of infants in southern India with Streptococcus pneumoniae.

To investigate the dynamics of nasopharyngeal colonization with Streptococcus pneumoniae, and to determine the prevalent serogroups/types (SGT) and their antimicrobial susceptibility, we studied 100 infants attending our well-baby clinic. Nasopharyngeal swab specimens were obtained at 6, 10, 14, 18 and 22 weeks and at 9 and 18 months of age and submitted for culture, serotyping and antimicrobial susceptibility testing of S. pneumoniae. Colonization with pneumococcus was seen on at least one occasion in 81 infants. The median age of acquisition was 11 weeks and the median duration of carriage was 1 3 months. The common SGTs identified were 6, 19, 14 and 15. SGT 1, which was a common invasive isolate in children in our hospital during this period, was not isolated from these children. Sequential colonization by 2, 3 or 4 SGTs was observed in 18, 5 and 2 children, respectively. Resistance to penicillin, chloramphenicol, cotrimoxazole and erythromycin was observed in 0, 13 (6%) 11 (5 %) and 5 (3 %) isolates, respectively. There was a significant difference in susceptibility to cotrimoxazole between colonizing and invasive isolates (5 % vs. 40 %, P<0.0001).

Drug Resistance, Microbial↗
PubMed1999

Molecular characterization of a globally distributed lineage of serotype 12F Streptococcus pneumoniae causing invasive disease.

These studies have identified a major genetic lineage of capsule serotype 12F Streptococcus pneumoniae, which has maintained two different types of the pneumococcal surface protein A (PspA) virulence factor and caused invasive disease in geographically disjoint locations. Twenty outbreak strains from a Texas jail and Maryland day care center and 16 reference strains from Texas, Maryland, Washington, Michigan, Oklahoma, Missouri, Alaska, and Australia were examined. Although the Texas and Maryland outbreak strains were indistinguishable by IS1167 and boxA genotyping procedures, all strains examined were members of a genetically similar lineage. The microevolutionary history of pspA differed from that of the overall genetic background of the strains. Taken together, these findings suggested that the Texas and Maryland outbreaks were caused by different clones of a major genetic lineage of serotype 12F pneumococci, within which at least one PspA has been acquired via localized genetic recombination.

Amino Acid Sequence↗
PubMed1999

Serotyping of Streptococcus pneumoniae by coagglutination with 12 pooled antisera.

We report on the performance of a recently introduced commercial chessboard method using 12 antisera, in comparison with that of the 55-antiserum panel used in determining the serogroups and types (SGTs) of Streptococcus pneumoniae, both of which were carried out by a coagglutination technique. Of a total of 150 strains of S. pneumoniae studied, 135 (90%) belonged to the SGTs represented in the 23-valent pneumococcal vaccine; of these, 130 (96.3%) were identified as the same SGTs by both typing methods. The remaining five strains showed cross-reactivity with more than two pools by the chessboard method, but could be assigned to a single SGT by the Quellung test. The 96.3% concordance of the chessboard method suggests it can be adopted for determination of the SGTs of S. pneumoniae in laboratories.

Agglutination Tests↗
PubMed1999

Changing trend in susceptibility pattern of Streptococcus pneumoniae to penicillin in India.

Prior to 1995 all strains of Streptococcus pneumoniae isolated at a tertiary care hospital in south India were uniformly susceptible to penicillin. However, since late 1995 strains of S. pneumoniae with intermediate resistance to penicillin have been observed. Altogether there were 25 such isolates, 9 from invasive (5 from CSF as well as blood, 1 from pleural fluid and 3 from CSF alone) and 16 from noninvasive sites (6 from throat, 6 from sputum, 3 from eye and 1 from ear) respectively, thus 4.6 per cent of S. pneumoniae showed intermediate resistance of a total of 535 strains studied so far. The minimum inhibitory concentration (MIC) values of penicillin, erythromycin, chloramphenicol and cefotaxime were determined by agar dilution method and for confirmation, E test was carried out for penicillin alone. The MIC range obtained for penicillin was between 0.125-1.0 microgram/ml. Kirby-Bauer disc diffusion method was adopted for testing of erythromycin, chloramphenicol, co-trimoxazole, cefotaxime, tetracycline and vancomycin. We observed that none of the strains with intermediate resistance to penicillin were multidrug resistant. These strains belonged predominantly to serotype 14 (n = 10), 7B (n = 9), 19A (n = 3), 7F (n = 2) and 23F (n = 1). Clonality was not observed in the 5 representative strains subjected to Box A finger printing method.

Anti-Bacterial Agents↗
PubMed1998

PCR-Enzyme immunoassay for detection of Streptococcus pneumoniae DNA in cerebrospinal fluid samples from patients with culture-negative meningitis.

A PCR-based assay was developed to amplify a conserved region of the pneumococcal autolysin gene. The amplified product was labelled with digoxigenin-labelled dUTP and was detected with a biotin-labelled probe in an enzyme immunoassay (EIA). The assay was initially tested with suspensions of various serotypes of Streptococcus pneumoniae and other gram-positive and gram-negative bacteria and was then applied to cerebrospinal fluid (CSF) specimens from patients with meningitis and those with other neurological disorders. The assay detected all the serotypes of S. pneumoniae tested, whereas all the other bacterial strains tested were negative. Seven of the 8 CSF specimens positive for pneumococcus by culture or latex agglutination (LA) were positive by PCR-EIA, whereas all 10 specimens positive for other organisms were negative. Among 11 patients with clinically diagnosed meningitis but with negative culture and LA results, 5 were positive by PCR-EIA. The assay was negative for all but one patient without meningitis; it was positive with the CSF from a child with immunodeficiency and pneumococcal abscesses on the scalp. PCR-EIA is a useful tool for the diagnosis of meningitis, especially when culture and LA are negative because of prior antibiotic treatment.

Child↗
PubMed1998

Invasive Haemophilus influenzae disease in India: a preliminary report of prospective multihospital surveillance. IBIS (Invasive Bacterial Infections Surveillance) Group.

OBJECTIVE: To determine the frequency, clinical characteristics and outcome of acute invasive infections caused by Haemophilus influenzae. DESIGN: Prospective hospital-based surveillance. SETTING: Six large academic referral hospitals in India. PARTICIPANTS: Three thousand four hundred forty-one patients from infancy to adulthood with pneumonia, meningitis or suspected bacterial sepsis. RESULTS: Preliminary data from 24 months of surveillance are presented. There were 58 H. influenzae isolates, of which 96% were serotype b. Nearly all isolates were from infants and children <5 years old, and most of the childhood isolates were from infants <1 year of age. Meningitis cases accounted for 69% of isolates. Overall case fatality was 11%. More than 50% of isolates were resistant to chloramphenicol, and up to 40% were resistant to ampicillin, trimethoprim-sulfamethoxazole or erythromycin. There was no resistance to third-generation cephalosporins. CONCLUSIONS: These preliminary data from six hospitals suggest a substantial burden of severe, preventable H. influenzae infections in India. The distribution of clinical syndromes and the ages of our Hib patients are fairly similar to data from North America and Europe.

Adolescent↗
PubMed1997

Effectiveness of clinical guidelines for the presumptive treatment of streptococcal pharyngitis in Egyptian children.

BACKGROUND: Primary prevention of acute rheumatic fever requires antibiotic treatment of acute streptococcal pharyngitis. In developing countries, clinicians must rely on clinical guidelines for presumptive treatment of streptococcal pharyngitis since bacterial culture and rapid diagnostic tests are not feasible. We evaluated the WHO Acute Respiratory Infection guideline in a large urban paediatric clinic in Egypt. METHODS: Children between 2 and 13 years of age who had a sore throat and pharyngeal erythema were enrolled in the study. Clinical, historical, and demographic information was recorded and a throat culture for group A beta-haemolytic streptococci was done. Sensitivity (% of true-positive throat cultures) and specificity (% of true-negative throat cultures) were calculated for each clinical feature. The effect of various guidelines on correct presumptive treatment for throat-culture status was calculated. FINDINGS: Of 451 children with pharyngitis, 107 (24%) had group A beta-haemolytic streptococci on throat culture. A purulent exudate was seen in 22% (99/450) of these children and this sign was 31% sensitive and 81% specific for a positive culture. The WHO Acute Respiratory Infections (ARI) guidelines, which suggest treatment for pharyngeal exudate plus enlarged and tender cervical node, were 12% sensitive and 94% specific; 13/107 children with a positive throat culture would correctly receive antibiotics and 323/344 with a negative throat culture would, correctly, not receive antibiotics. Based on our data we propose a modified guideline whereby exudate or large cervical nodes would indicate antibiotic treatment, and this guideline would be 84% sensitive and 40% specific; 90/107 children with a positive throat culture would correctly receive antibiotics and 138/344 with a negative throat culture would, correctly, not receive antibiotics. INTERPRETATION: The WHO ARI clinical guideline has a high specificity but low sensitivity that limits the unnecessary use of antibiotics, but does not treat 88% of children with a positive streptococcal throat culture who are at risk of acute rheumatic fever. A modified guideline may be more useful in this population. Prospective studies of treatment guidelines from many regions are needed to assess their use since the frequency of pharyngitis varies.

Adolescent↗