תוצאת חיפוש

Characteristics of Nasopharyngeal Carriage of Streptococcus Pneumoniae in Children During Acute Respiratory Disease

A. Aran¹, D. Fraser², R. Dagan¹

Pediatric Infectious Disease Unit¹, Epidemiology Department², Soroka University Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva

Streptococcus pneumoniae is an important cause of pediatric morbidity and its main reservoir is the nasopharynx, from which it can disseminate and cause invasive disease. From November 1997 through March 1998, nasopharyngeal carriage of S. pneumoniae was evaluated in 250 children under the age of 36 months: 123 Jews and 127 Bedouins with acute respiratory disease and in 980 healthy control children (852 Jews and 128 Bedouins).

Carriage rate was higher among sick children. Among Jewish children it was 57% and 35% of sick and healthy children respectively (p<0.01), and among Bedouin children it figured as 80% and 67% respectively (p=0.01). The difference in carriage rate was most prominent in infants under the age of 5 months: among Jewish children it was 60% and 27% of sick and healthy children respectively (p<0.001) and among Bedouins it was 82% and 65% respectively (p=0.05).

Higher carriage rate of penicillin resistant pneumococci (PRP) was also detected in sick children, with no relation to antibiotic treatment in the month prior to sampling. In Jewish children PRP was detected in 12%, 28% (p<0.001) and 36% (p<0.001) of healthy children, sick children with previous antibiotic treatment and sick children with no treatment, respectively.

The seroypes included in the newly developed 7-valent conjugate vaccine: 4, 6B, 9V, 14, 18C, 19F, 23F, that are highly pathogenic and often antibiotic resistant contributed 74% of isolates in sick Jewish children who had previous antibiotic treatment and 39% of isolates in healthy children (p<0.001). In Bedouin children vaccine types carriers rate among the sick children was not higher than in healthy children.

Acute respiratory disease increases the risk of pneumococcal carriage in general and carriage of resistant pneumococci in particular. Previous antibiotic treatment increases the risk of carring one of the pathogenic serotypes included in the 7-valent vaccine. The impact of disease is most prominent in infants under 5 months, since they are usually less exposed to S. pneumoniae carriers than older children.

Since the increase in carriage rate during illness is mostly due to the serotypes included in the newly developed conjugate vaccine, future immunization programme may decrease not only morbidity rate but also nasopharyngeal carriage rate of pneumococci in general and of antibiotic-resistant pneumococci in particular.

Development of Molecular Tests for Rapid Detection of Enteropathogens 

Miri Yavzori, Nir Uriel, Nurith Porat, Ron Dagan, Ruhama Ambar, Ofer Shpilberg, Dani Cohen

Army Health Branch Research Unit, Medical Corps, Israel Defense Forces; Pediatric Infectious Disease Unit, Soroka University Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba; and Sackler Faculty of Medicine, Tel Aviv University

Amplification of specific DNA sequences by polymerase chain reaction (PCR), enables rapid, sensitive and direct, specific identification of pathogens at very low concentrations in clinical samples. Studies in recent years have reported identification of several enteropathogens directly from stool samples by PCR. The amplification process includes the use of primers complementary to the DNA sequences specific to the pathogen, thus relying on the pathogen's genotype, rather than its phenotype on which identification by the methods of classical microbiology were based.

We have developed PCR protocols for the differential identification of enteropathogens resembling the normal flora (enterotoxigenic E. coli (ETEC), E. coli O-157), Shigella spp, and the detection of enteropathogens that can not be grown on classic growth media (Norwalk virus). The amplification process is inhibited by several substrates present in fecal material (phenol, hemoglobin), limiting DNA extraction by phenol. The protocols we have developed for direct detection of Shigella spp and ETEC in stools circumvent inhibition of PCR by the use of a 4-hour pre-enrichment step in brain-heart infusion broth.

Rapid and accurate identification of enteropathogens is important for prompt and focused intervention to stop the chain of transmission in outbreaks of gastroenteritis in military and civilian populations.

Epidemiology of Invasive Hemophilus Influenzae B Infections in Bedouins and Jews; Conjugate Hib Vaccines

Limor Gortzak-Uzan*, Drora Fraser, Ron Dagan

Pediatric Infectious Disease Unit and Dept. of Epidemiology, Soroka Medical Center and Ben-Gurion University of the Negev, Beer Sheba

From 1989 to 1996, 139 cases of invasive Hemophilus influenzae B (Hib) infections were identified in children in the Negev, 110 of which occurred before introduction of the conjugate vaccine (1989-92). At that time there were 60.5 cases of Hib per 100,000 in the Negev among children under 5 years of age. During 1995-1996, when Hib conjugate vaccine was part of the regular immunization program, Hib decreased to 6.5 cases per 100,000 in that age group. The effectiveness of PRP-OMP vaccine was 96.5% among Jews and 89% among Bedouins, and the efficacy of the immunization program was 99.99%. This degree of success exceeded all expectations based on the literature. During the whole study period, Hib infections were more frequent among Bedouins than Jews. There was no significant difference in the occurrence of Hib among Jews in the Negev before and after the vaccine was introduced. Hib among Bedouins in the Negev was significantly more frequent than in the Israeli population as a whole before the vaccine was introduced. That gap narrowed after the vaccine was introduced because of the decrease in morbidity among the 2 groups.

* Medical student.

First Year's Experience of the Post, Operative Cardiac Care Unit, Schneider Children's Medical Center

O. Dagan, E. Birk, J. Katz, B. Vidne

Cardiothoracic Pediatric Service, Schneider Children's Medical Center, Petah Tikva

In the past 10 years there has been a growing preference for early, complete correction of congenital heart disease. The first year of operation of this cardiac unit is described. 216 operations were performed: 15% in the neonatal age group and 35% in the newborn to l-year-old groups; 2% were palliative procedures. Mortality was 4.9%. Average stay in the ICU was 3.2  days, with a median of 2.25. Average length of ventilation was 35 hours, with a median of 17.5. Complications were: diaphragm paralysis in 13 (6%), 2/3 of which were recurrent operations; in 2 patients (0.9%) we had to plicate the diaphragm. There was severe neurological damage in 2, which deteriorated to brain death in 1. There was peripheral, reversible neurological damage in 4 (1.8%), and acute renal failure in 3%, with half of them requiring dialysis. 75% of these children died and there was superficial infection in 4.1%, deep wound infection in 1.3%, bacteremia in 4.1%, superior vena cava syndrome in 3 (1.3%) and chylothorax in 2 of them (0.9%). 1 patient (0.45%) required a ventricle-peritoneal shunt after acute viral meningitis. We are encouraged by our results to offer early complete correction to all children with congenital heart disease.

Gram-Negative Enteric Bacteremia in Children in the Negev

Michal Maimon-Greenwald, Eugene Leibovitz, Nimrod Maimon, Nechama Peled, Ron Dagan

Pediatric Infectious Disease Unit and Clinical Microbiology Laboratory, Soroka Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba

During 1989-1994, there were 322 episodes of Gram-negative enteric bacteremia in 308 children. The incidence increased from 31/100,000 in children younger than 15 years of age during 1989-1991, to 50/100,000 during 1992-1994. The most common pathogens were Klebsiella, E. Coli, Salmonella and Enterobacter. 39% of episodes were nosocomial and a significant increase was recorded for each species during the last 3 years of the study. Klebsiella represented the most common pathogen causing nosocomial bacteremia, while E. coli and Salmonella were the main pathogens causing community-acquired bacteremia. In this study in southern Israel, the incidence of Gram-negative enteric bacteremia was significantly higher in Bedouin children, with the exception of bacteremia due to Salmonella, which occurred mainly in Jewish children.

Epidemiologic Characteristics of Pediatric Emergency Room Referral and Hospitalization for Diarrhea in the Negev

Moni Benifla, Drora Fraser, Zvi Weizman, Amalia Levy, Ron Dagan

Dept. of Epidemiology and Health Services Evaluation and S. Daniel International Center for Health and Nutrition, Ben-Gurion University of the Negev, and Pediatric Dept. and Pediatric Infectious Disease Unit, Soroka Medical Center and Ben-Gurion University of the Negev

Diarrheal diseases weigh heavily on the health of children, especially in developing countries, but also impose burdens on health care services worldwide. This study was performed to determine whether patterns of referrals in the Negev to the pediatric emergency room (PER) for diarrhea differ between the Jewish and Bedouin populations of the Negev, and the extent of the burden imposed on the PER and in-hospital services in the Negev. Characteristics of referrals and hospitalizations were examined from March 1994 to February 1995. Of the 27,834 referrals to the PER for children under 16, 2518 (9%) had diarrhea and there were 5,169 hospital admissions, 701 (13.6%). The annual rates of referral were 146 per 10,000 in Jews and 225 in Bedouin, giving an odds ratio (OR) of 1.5 (p<0.001). for Bedouin. The rates of hospitalization were 23 per 10,000 in Jews and 99 in Bedouin (OR 4.4, p<0.001). 1380 (54.8%) of the PER referrals were of infants under a year of age. For hospitalization, the annual rates were 164 per 10,000 in Jews and 756 in Bedouins (OR 4.9, p<0.001). During June to August referrals and hospitalizations for diarrhea were significantly higher, and from December to February significantly lower than during the remaining months. These differences arise from the marked seasonal pattern in the Bedouin population, whereas in the Jewish population there was no seasonal variation. Even in the 90's the burden on health services in the Negev as a result of diarrheal illness is considerable and the Bedouin population still contributes to that burden disproportionately. There is need both to reduce the gap in referrals and hospitalization between the populations, as well as to reduce the rates, using currently available means such as education, while developing new technologies, such as vaccines.