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Mathuram Santosham

Publications and source records attributed to Mathuram Santosham.

At least 37 records · Page 2Linked to original sources
PubMed2005

Prevention of Haemophilus influenzae type b disease: past success and future challenges.

Haemophilus influenzae type b (Hib) is responsible for significant morbidity and mortality worldwide, particularly in children under 5 years of age. In countries where the Hib conjugate vaccine is not routinely used, Hib is a leading cause of childhood pneumonia and meningitis. Routine use of the Hib conjugate vaccines has resulted in a remarkable decline in Hib disease in developed and developing countries. However, Hib conjugate vaccines are not routinely available in most developing countries, many of which have high burdens of Hib disease. This review outlines the pathogenesis and epidemiology of Hib disease, and the various options for prevention.

Child↗
PubMed2004

Epidemiology of invasive Streptococcus pneumoniae among Navajo children in the era before use of conjugate pneumococcal vaccines, 1989-1996.

Streptococcus pneumoniae is the most common cause of invasive bacterial disease among children worldwide. The authors aimed to determine the incidence, clinical characteristics, and serotype distribution of invasive pneumococcal disease (IPD) among Navajo children in the southwestern United States. Active population-based laboratory surveillance for IPD among resident members of the Navajo Nation under 18 years of age was conducted between 1989 and 1996. During this 8-year period, 706 cases of IPD were identified. The rate of disease varied by age, with the highest rate being observed among children aged 6-11 months (727 cases/100,000 person-years), followed by children aged 0-11 months, 0-23 months, and 0-59 months (568, 537, and 272 cases/100,000 person-years, respectively). Among children aged 0-23 months, 60.3% of cases were caused by serotypes in the seven-valent conjugate pneumococcal vaccine (71.5% from 1989-1993 and 58.3% from 1994-1996). Navajo children are at increased risk of IPD in comparison with the general US population. The distribution of disease-causing serotypes is similar to that of many countries in the developing world. Prevention strategies should include the use of licensed pneumococcal protein conjugate vaccine; however, a substantial proportion of disease is caused by nonvaccine serotypes. These data are critical for assessing the impact of these vaccines in this high-risk population.

Age Distribution↗
PubMed2004

Zinc for severe pneumonia in very young children: double-blind placebo-controlled trial.

BACKGROUND: Pneumonia is a leading cause of morbidity and mortality in young children. Early reversal of severity signs--chest indrawing, hypoxia, and tachypnoea--improves outcome. We postulated that zinc, an acute phase reactant, would shorten duration of severe pneumonia and time in hospital. METHODS: In a double-blind placebo-controlled clinical trial in Matlab Hospital, Bangladesh, 270 children aged 2-23 months were randomised to receive elemental zinc (20 mg per day) or placebo, plus the hospital's standard antimicrobial management, until discharge. The outcomes were time to cessation of severe pneumonia (no chest indrawing, respiratory rate 50 per min or less, oxygen saturation at least 95% on room air) and discharge from hospital. Discharge was allowed when respiratory rate was 40 per minute or less for 24 consecutive hours while patients were maintained only on oral antibiotics. FINDINGS: The group receiving zinc had reduced duration of severe pneumonia (relative hazard [RH]=0.70, 95% CI 0.51-0.98), including duration of chest indrawing (0.80, 0.61-1.05), respiratory rate more than 50 per min (0.74, 0.57-0.98), and hypoxia (0.79, 0.61-1.04), and overall hospital duration (0.75, 0.57-0.99). The mean reduction is equivalent to 1 hospital day for both severe pneumonia and time in hospital. All effects were greater when children with wheezing were omitted from the analysis. INTERPRETATION: Adjuvant treatment with 20 mg zinc per day accelerates recovery from severe pneumonia in children, and could help reduce antimicrobial resistance by decreasing multiple antibiotic exposures, and lessen complications and deaths where second line drugs are unavailable.

Anti-Bacterial Agents↗
PubMed2004

Long-term efficacy of BCG vaccine in American Indians and Alaska Natives: A 60-year follow-up study.

CONTEXT: The duration of protection from tuberculosis of BCG vaccines is not known. OBJECTIVE: To determine the long-term duration of protection of a BCG vaccine that was previously found to be efficacious. DESIGN: Retrospective record review using Indian Health Service records, tuberculosis registries, death certificates, and supplemental interviews with trial participants. SETTING AND PARTICIPANTS: Follow-up for the period 1948-1998 among American Indians and Alaska Natives who participated in a placebo-controlled BCG vaccine trial during 1935-1938 and who were still at risk of developing tuberculosis. Data from 1483 participants in the BCG vaccine group and 1309 in the placebo group were analyzed. MAIN OUTCOME MEASURES: Efficacy of BCG vaccine, calculated for each 10-year interval using a Cox regression model with time-dependent variables based on tuberculosis events occurring after December 31, 1947 (end of prospective case finding). RESULTS: The overall incidence of tuberculosis was 66 and 138 cases per 100 000 person-years in the BCG vaccine and placebo groups, respectively, for an estimate of vaccine efficacy of 52% (95% confidence interval, 27%-69%). Adjustments for age at vaccination, tribe, subsequent BCG vaccination, chronic medical illness, isoniazid use, and bacille Calmette-Guérin strain did not substantially affect vaccine efficacy. There was slight but not statistically significant waning of the efficacy of BCG vaccination over time, greater among men than women. CONCLUSION: In this trial, BCG vaccine efficacy persisted for 50 to 60 years, suggesting that a single dose of an effective BCG vaccine can have a long duration of protection.

BCG Vaccine↗
PubMed2004

Potential impact of conjugate pneumococcal vaccines on pediatric pneumococcal diseases.

Children younger than age 2 years have the highest rates of invasive pneumococcal disease and play an important role in its transmission. In the United States, seven pneumococcal serotypes cause approximately 80% of invasive disease and represent approximately 60% of middle-ear isolates in children younger than age 2 years; the majority of penicillin-resistant strains are confined to these same few serogroups. Although unconjugated polysaccharide pneumococcal vaccines have demonstrated effectiveness in preventing invasive disease in adults, these vaccines fail to protect against otitis media or nasopharyngeal carriage and are poorly immunogenic in children younger than age 2 years. A new generation of pneumococcal vaccines has been developed, linking the capsular polysaccharide of seven to 11 serotypes to a protein carrier. The only pneumococcal vaccine approved to date for children younger than age 2 years is a seven-valent conjugate vaccine (PnCRM-7) (Prevnar; Wyeth Vaccines, Pearl River, New York), which contains serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F. PnCRM-7 is more immunogenic than the polysaccharide pneumococcal vaccines and is 80-100% effective against vaccine-type invasive disease and 50-60% effective against vaccine-type pneumococcal otitis media. Routine immunization with pneumococcal conjugate vaccines should substantially reduce the morbidity, mortality, and costs associated with pneumococcal disease in children.

Child, Preschool↗
PubMed2004

Safety and immunogenicity of two octavalent pneumococcal conjugate vaccines in American Indian infants.

We evaluated the safety and immunogenicity of two octavalent pneumococcal polysaccharide vaccines (serotypes 3, 4, 6B, 9V, 14, 18C, 19F, and 23F) conjugated to either diphtheria toxoid (PncD) or tetanus protein (PncT) among White Mountain Apache and Gila River Indian Community infants. This was a prospective, non-randomized, open label, comparative pilot study of PncD and PncT. Since this was a pilot study, a small sample size of 60 infants was enrolled. Enrolled healthy infants received either PncD or PncT at 2, 4, and 6 months of age. Antibody concentrations were measured by enzyme-immunoassay (EIA) prior to each dose and 1 month after the last dose. Local reaction rates were similar between PncD and PncT groups. The geometric mean concentrations (GMCs) were significantly higher for PncD than PncT for serotype 3 whereas GMCs were significantly higher for PncT for serotype 4. For this pilot study, both vaccines appeared to be safe and immunogenic in this group of American Indian infants.

Adjuvants, Immunologic↗
PubMed2004

Invasive pneumococcal disease among Navajo adults, 1989-1998.

Compared with white and black persons in the United States, some Native American groups are at increased risk for invasive pneumococcal disease (IPD). To characterize the epidemiology of IPD among Navajo adults, we conducted active surveillance for IPD on the Navajo Nation and reviewed medical records of patients with IPD. For 1997-1998, the annual incidence (cases per 100,000 persons) was 56 for Navajos aged 18-64 years and 190 for Navajos aged > or =65 years. The corresponding rates were 10 and 57 for white and 44 and 82 for black persons in the United States. The case-fatality rate was 14%. Eighty percent of cases were caused by serotypes included in the 23-valent pneumococcal polysaccharide vaccine. Navajo adults have rates of IPD that are 3-5-fold higher than those of the general US population. Additional research is needed to understand the reasons for this elevated risk and to develop prevention strategies.

Adolescent↗
PubMed2004

Safety and efficacy of a premixed, rice-based oral rehydration solution.

UNLABELLED: The authors compared the safety and efficacy of a ready-to-use, premixed, rice-based oral rehydration solution (R-ORS) with a glucose-based oral rehydration solution (G-ORS), each containing 75 mmol/L sodium, in Mexican children with acute diarrhea for less than 5 days. METHODS: One hundred eighty-nine boys 3 to 24 months old admitted to the hospital with acute diarrhea and signs of dehydration were randomly assigned to receive either G-ORS or R-ORS. Intake and output were measured every 3 hours. RESULTS: In the group treated with R-ORS, significantly fewer patients required supplemental intravenous fluids during the rehydration phase compared to the G-ORS group (1% v 8.7%; P < 0.01). Mean stool output, percent weight gain, ORS intake, urine output, and number of patients who vomited during rehydration were similar in the two groups. The mean total stool output after the first 24 hours of maintenance phase was significantly lower in the R-ORS group than in the G-ORS group. CONCLUSIONS: The authors found rice-based ORS to be safe, and its use reduced the rate of intravenous fluid therapy in comparison with the use of a glucose-based ORS.

Acute Disease↗
PubMed2004

Nasopharyngeal versus oropharyngeal sampling for detection of pneumococcal carriage in adults.

Several studies have shown that nasopharyngeal sampling is more sensitive than oropharyngeal sampling for the detection of pneumococcal carriage in children. The data for adults are limited and conflicting. This study was part of a larger study of pneumococcal carriage on the Navajo and White Mountain Apache Reservation following a clinical trial of a seven-valent pneumococcal conjugate vaccine. Persons aged 18 years and older living in households with children enrolled in the vaccine trial were eligible. We collected both nasopharyngeal and oropharyngeal specimens by passing a flexible calcium alginate wire swab either nasally to the posterior nasopharynx or orally to the posterior oropharynx. Swabs were placed in skim milk-tryptone-glucose-glycerin medium and frozen at -70 degrees C. Pneumococcal isolation was performed by standard techniques. Analyses were based on specimens collected from 1,994 adults living in 1,054 households. Nasopharyngeal specimens (11.1%; 95% confidence interval [CI], 9.8 and 12.6%) were significantly more likely to grow pneumococci than were oropharyngeal specimens (5.8%; 95% CI, 4.8 to 6.9%) (P < 0.0001). Few persons had pneumococcal growth from both specimens (1.7%). Therefore, both tests together were more likely to identify pneumococcal carriage (15.2%; 95% CI, 13.7 to 16.9%) than either test alone. Although we found that nasopharyngeal sampling was more sensitive than oropharyngeal sampling, nasopharyngeal sampling alone would have underestimated the prevalence of pneumococcal carriage in this adult population. Sampling both sites may give more accurate results than sampling either site alone in studies of pneumococcal carriage in adults.

Adult↗
PubMed2004

Zinc therapy for diarrhoea increased the use of oral rehydration therapy and reduced the use of antibiotics in Bangladeshi children.

Excessive use of antibiotics for diarrhoea is a major contributing factor towards increasing rates of antimicrobial resistance in developing countries. Zinc therapy for diarrhoea has been shown to be beneficial in controlled efficacy trials, and it is of interest to determine if availability of zinc syrup for treatment of diarrhoea would satisfy the demand for a 'medicine' for diarrhoea, thus reducing the use of antibiotics, without competing with the use of oral rehydration therapy (ORT). This community-based controlled trial was conducted from November 1998 to October 2000, and all children aged 3-59 months in the study area were included. In this trial, the availability of zinc supplements, along with ORT and appropriate education programmes, was associated with significantly higher use of ORT and lower use of antibiotics.

Anti-Bacterial Agents↗
PubMed2003

Efficacy and safety of seven-valent conjugate pneumococcal vaccine in American Indian children: group randomised trial.

BACKGROUND: Streptococcus pneumoniae is the main cause of invasive bacterial disease in children aged younger than 2 years. Navajo and White Mountain Apache children have some of the highest rates of invasive pneumococcal disease documented in the world. We aimed to assess the safety and efficacy of a seven-valent polysaccharide protein conjugate pneumococcal vaccine (PnCRM7) against such disease. METHODS: In a group-randomised study, we gave this vaccine to children younger than 2 years from the Navajo and White Mountain Apache Indian reservations; meningococcal type C conjugate vaccine (MnCC) served as the control vaccine. Vaccine schedules were determined by age at enrollment. We recorded episodes of invasive pneumococcal disease and serotyped isolates. Analyses were by intention to treat and per protocol. FINDINGS: 8292 children enrolled in the trial. In the per protocol analysis of the primary efficacy group (children enrolled by 7 months of age) there were eight cases of vaccine serotype disease in the controls and two in the PnCRM7 group; in the intention-to-treat analysis we noted 11 cases of vaccine serotype disease in the MnCC control group and two in the PnCRM7 group. After group randomisation had been controlled for, the per protocol primary efficacy of PnCRM7 was 76.8% (95% CI -9.4% to 95.1%) and the intention-to-treat total primary efficacy was 82.6% (21.4% to 96.1%). INTERPRETATION: PnCRM7 vaccine prevents vaccine serotype invasive pneumococcal disease even in a high risk population. Other regions with similar disease burden should consider including this vaccine in the routine childhood vaccine schedule.

Arizona↗
PubMed2003

Effectiveness of the 23-valent polysaccharide vaccine against invasive pneumococcal disease in Navajo adults.

Invasive pneumococcal disease occurs 2-3-fold more often among Navajo adults than among adults in the general United States population. The objective of this observational study was to determine the effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPV23) among Navajo adults. Active surveillance identified cases of invasive pneumococcal disease during 1996-1997. Three control patients per case patient were matched according to underlying medical conditions, sex, age, and location of medical care. Effectiveness was calculated by regression analysis of case-control sets and by indirect cohort methodology. Diabetes and alcoholism occurred in 41% and 43% of 108 case patients, respectively; 62% of case patients and 64% of control patients were immunized. Overall vaccine effectiveness was 26% (95% confidence interval [CI], -29% to 58%); 15% (95% CI, -116% to 67%) for patients with diabetes and -5% (95% CI, -141% to 54%) for patients with alcoholism. Overall vaccine effectiveness, as determined by use of the indirect cohort methodology, was 35% (95% CI, -33% to 69%). PPV23 was not significantly effective among Navajo adults and may be inadequate to prevent serious pneumococcal disease in this population.

Adult↗
PubMed2003

Prevalence of hepatitis C virus infection in urban children.

OBJECTIVES: To determine the prevalence of hepatitis C virus (HCV) infection in children with an unknown or negative human immunodeficiency virus (HIV) status attending an urban hospital pediatric primary care clinic, and to identify HCV risk factors in their mothers. STUDY DESIGN: This was a cross-sectional study of 1034 children tested for HCV antibodies (anti-HCV) after excluding children known to be HIV-positive. We assessed maternal HCV risk factors through structured interviews with a sample of mothers (n=573) and through review of available medical records (n=347) for a subsample of mother-child pairs. Means, proportions, and 95% confidence intervals were used to estimate the prevalence of anti-HCV and maternal risk factors. RESULTS: One child (0.1%; 95% CI, 0.002, 0.5) was anti-HCV positive. History of blood transfusion was reported by 7% of mothers and intravenous drug use (IVDU) by 1.8%. A subsample of mothers significantly underreported IVDU when compared with medical record review (1.5% vs 7.8%, P<.001). CONCLUSIONS: Our findings suggest that universal screening of children for HCV in high-risk urban communities is not warranted. However, self-report may not be reliable for identifying mothers with a history of IVDU, for whom HCV testing is recommended.

Child↗
PubMed2003

Global reduction of Hib disease: what are the next steps? Proceedings of the meeting Scottsdale, Arizona, September 22-25, 2002.

On September 22 to 25, 2002, a group of infectious disease specialists, public health officials, and vaccine experts from 33 countries gathered in Scottsdale, Arizona, to discuss the epidemiology and control of disease caused by Haemophilus influenzae type b (Hib) in the era of Hib conjugate vaccines. This supplement is a synthesis of the major themes and key lessons identified at the meeting. The objectives of the conference were to review the 10-year experience with Hib conjugate vaccines, discuss strategies to reduce Hib disease rates to lowest possible levels in industrialized countries, review impediments to the introduction of Hib vaccine in developing countries, and discuss strategies for disseminating lessons learned from countries using to those not using Hib conjugate vaccines. Over 10 years of international experience with Hib conjugate vaccines has demonstrated that they are safe and effective. Routine use of Hib conjugate vaccine has consistently led to decreases in the incidence of invasive Hib disease of 90% or more across a wide range of epidemiologic situations in industrialized countries. In some countries, the vaccine has caused a near-disappearance of invasive Hib disease through a combination of direct protection and herd immunity. Developing countries that have implemented routine vaccination (eg, The Gambia, Chile) have also had substantial disease reduction. In countries where Hib conjugate vaccine is being used, reducing Hib disease incidence to the lowest possible level will depend on maintaining high vaccine coverage levels, conducting surveillance for Hib disease, and investigating Hib disease cases. The optimal Hib vaccination strategy will depend on many factors, including local epidemiology and programmatic considerations. In countries that are not using Hib conjugate vaccine, information on the local burden of Hib disease will be essential for leaders considering vaccine introduction. Where disease burden is high, a multifaceted approach is urgently needed to evaluate and overcome barriers to vaccine introduction. In areas where Hib disease burden is not well characterized, additional work will be needed to understand the epidemiology of Hib disease and to communicate the value of Hib conjugate vaccine.

Child↗
PubMed2003

Comparison of antibiotic resistance and serotype composition of carriage and invasive pneumococci among Bangladeshi children: implications for treatment policy and vaccine formulation.

The nasopharyngeal carriage of Streptococcus pneumoniae is thought to pose a risk for invasive pneumococcal diseases, and the evaluation of carriage strains is thus often used to inform antibiotic treatment and vaccination strategies for these diseases. In this study, the age-specific prevalences, resistance to antibiotics, and serotype distributions of 1,340 carriage strains were analyzed and compared to 71 pneumococcal strains isolated from the cerebrospinal fluid of children under 5 years old with meningitis. Overall, the nasal carriage rate was 47%. One-fourth (26%) of the infants under 1 month of age and one-half (48%) of the infants under 12 months of age were colonized with S. pneumoniae. Rural children were colonized earlier than those from urban areas. Approximately one-fourth and one-half of the cases of pneumococcal meningitis occurred in the first 3 and 6 months of life, respectively. The respective rates of resistance for carriage and meningitis strains to penicillin (7 and 3%), cotrimoxazole (77 and 69%), and erythromycin (2 and 1%) were similar, whereas chloramphenicol resistance was lower among carriage strains (3%) than among meningitis strains (15.5%). The predominant serogroups of carriage and invasive isolates were variable and widely divergent. Thus, hypothetical 7-, 9-, and 11-valent vaccines, based on the predominant carriage strains of the present study, would cover only 23, 26, and 30%, respectively, of the serotypes causing meningitis. Further, currently available 7-, 9-, and 11-valent vaccines would protect against only 26, 43, and 48%, respectively, of these meningitis cases. In conclusion, while the surveillance of carriage strains for resistance to antibiotics appears useful in the design of empirical treatment guidelines for invasive pneumococcal disease, data on the serotypes of carriage strains have limited value in vaccine formulation strategies, particularly for meningitis cases.

Age Distribution↗
PubMed2003

Transient and persistent Helicobacter pylori colonization in Native American children.

Helicobacter pylori is chiefly acquired in childhood, but the exact timing of acquisition is not well understood. The main goal of this study was to assess H. pylori acquisition in a pediatric population. We studied two cohorts of Native American children: a birth cohort of 50 children and 58 older children (mean age, 53 months). We measured serum immunoglobulin G (IgG), IgM, and IgA antibodies to H. pylori whole-cell antigen and IgG antibodies to CagA. Among 44 birth cohort children monitored for more than 12 months, 24 (54.5%) had seroconversions, 7 (15.9%) were transient, and 17 (38.6%) were persistent. Among the older children, 49 (84.5%) of the 58 children were monitored for 1 year; 34 (69.4%) had H. pylori antibodies at study entry. During the next year, 7 (20.6%) children seroreverted, and of 15 initially negative children, 5 (33.3%) seroconverted. In both groups, evaluation of CagA antibodies increased the sensitivity of H. pylori detection. Serum pepsinogen I (PGI) levels in H. pylori-negative children rose significantly until age 6 months and remained constant for the next 19 months. At the time of H. pylori seroconversion, PGI peaked to levels significantly higher than in the never-seroconverted (P = 0.02) and the pre-seroconverted (P = 0.03) children, but then declined to levels paralleling those of H. pylori-negative children. Thus, H. pylori acquisition, accompanied by a transient PGI increase, was frequent in this population, especially in the second and third years of life, but often was brief.

Adult↗