Forty years of meningococcal disease in Israel: 1951-1990

Meningococcal disease accounts for approximately 20% of cases of bacterial meningitis in Israel. During the period 1951-1990, the annual incidence of meningococcal disease rarely exceeded two cases per 100,000 persons and was generally higher among non-Jews (largely the Arab population) than among Jews; there were some notable peaks of disease activity during 1963-1967, 1975, and 1987-1988. The highest incidence was among infants and young children, with a slight male predominance. The main period of disease activity was from January to April, but an unusual secondary peak in July coincided with the onset of peak summer temperatures. Monthly disease frequencies were significantly correlated with relative humidity. Incidence rates varied between regions and were lower in cities than in smaller settlements. Overall case-fatality rates decreased to approximately 11% for the period 1981-1990. Outbreaks were infrequent and tended to be small. Meningococci of serogroup B have dominated since the mid-1970s. Group A meningococci were isolated significantly more commonly from Arabs (26.26%) than from Jews (1.03%; P < .000001). The frequency with which group A organisms occurred among clinical isolates appeared to follow a more or less cyclical pattern.

Role of cadmium in activating nuclear protein kinase C and the enzyme binding to nuclear protein

Specific effects of cadmium on nuclear protein kinase C activity were found with 3T3/10T1/2 mouse fibroblast and rat liver nuclei. Treatment of the mouse fibroblasts in culture with 12-O-tetradecanoylphorbol-13-acetate resulted in the stimulation of nuclear protein kinase C activity in a "fixed" pool which is defined by its resistance to chelator extraction, whereas the chelator extractable enzyme activity, defined as the "labile" pool was unaffected. Cadmium was found to potentiate the effect of the phorbol ester, directed specifically to nuclei, since the particulate protein kinase C activity was not changed under similar treatment. In a reconstituted system consisting of rat liver nuclei and rat brain protein kinase C, cadmium stimulated the binding of the enzyme to a 105-kDa nuclear protein. The binding of a 105-kDa protein to protein kinase C is attributed strictly due to the cadmium effect, whereas a 50-kDa protein binding to protein kinase C was only enhanced by cadmium. We propose a mechanistic model, where cadmium substitutes zinc in the regulatory domain of protein kinase C rendering the putative protein-protein binding site exposed.

Effect of labor and delivery on neonatal polymorphonuclear leukocyte number and function

The ability of the neonate to mount an adequate polymorphonuclear leukocyte (PMN) response, either quantitatively or functionally, is impaired. To assess whether neonatal PMN number and function are altered by labor and delivery, three groups of infants were studied: cesarean section without labor (10), cesarean section after labor (10), and vaginal delivery (11). PMN counts were higher in the groups undergoing labor (p less than 0.01) compared with the cesarean section without labor group. Similarly, the labor groups had evidence of complement activation (increased C3a desarg) compared with the cesarean section without labor group. No differences were noted between the groups in measures of PMN motility (chemokinesis or chemotaxis) or PMN degranulation (plasma lysozyme), suggesting that normal labor and delivery does not contribute to the general PMN dysfunction of the neonate.

Enhancement of neonatal neutrophil motility (chemotaxis) with adult fresh frozen plasma

We examined the effect of adult fresh frozen plasma (FFP) on neonatal neutrophil (PMN) motility (chemotaxis) using a micropore filter assay. Adult FFP was transfused into 13 neonates receiving FFP transfusion for suspected life-threatening sepsis. Blood was obtained from neonates before and after FFP transfusion for assessment of PMN chemotaxis. An increase in PMN chemotaxis was noted in 12 of the 13 neonates following FFP transfusion, with a mean percentage increase of 12 +/- 3% (p less than 0.01). PMN chemotaxis increased 13 +/- 2% (p less than 0.01) in four bacteremic infants and 11 +/- 5% (p = 0.06) in nine infants without bacteremia. Adult FFP transfusion may enhance impaired neonatal PMN motility and improve outcome from infection in newborn infants.

Detection and treatment of brucellosis by screening a population at risk

Brucellosis presents a difficult diagnostic challenge in view of its protean manifestations, multiple organ involvement and variable clinical course. The purpose of the present study was to determine whether active screening of a population at risk, identified through index cases, would enhance the detection rate of brucellosis and improve treatment. During a 1-month period all 98 individuals sharing risk factors with 4 diagnosed symptomatic cases of brucellosis in one Bedouin town in southern Israel were approached and 86 agreed to undergo screening. Symptomatic brucellosis was found in 8 (9%) of the screened population and an additional 5 (6%) asymptomatic individuals were found to be seropositive. These 13 were followed for 12 months. All symptomatic cases were treated and cured. Of the 5 asymptomatic seropositive individuals 2 showed a further elevation of Brucella antibody titers. One became symptomatic, was treated and was cured. This screening program provided 53% of all reported cases from the Bedouin town during the entire year of the study. Screening a population at risk increased the detection rate of brucellosis and improved the treatment.

Reduction of transmission of shigellosis by control of houseflies (Musca domestica)

The effect of control of houseflies on the incidence of diarrhoea and shigellosis was evaluated in a prospective crossover intervention study at two military field bases several kilometers apart. In early summer, 1988, intensive fly control measures (mainly bait and trap strategy) were introduced on one base, while the other served as a control. After 11 weeks, as new cohorts arrived, the intervention was abruptly discontinued in the first base and instituted in the second for the next 11 weeks. The study was repeated the next summer. Overall, fly counts were 64% lower on the bases exposed to fly control measures (p = 0.024). Concomitantly, clinic visits dropped by 42% (p = 0.146) for diarrhoeal diseases and by 85% for shigellosis (p = 0.015), as did rates of seroconversion, by 76% (p = 0.024) for antibodies to Shigella and by 57% (p = 0.006) for antibodies to enterotoxigenic Escherichia coli. The findings indicate that houseflies, acting as mechanical vectors, transmit Shigella (and possibly enterotoxigenic E coli) diarrhoeal infections.

Four decades of shigellosis in Israel: epidemiology of a growing public health problem

Despite the improved standard of living in Israel, shigellosis remains a common disease. Examination of trends in the incidence of shigellosis in Israel between 1951 and 1987 showed a period of declining rates followed by an increase in the reported incidence beginning around 1969. This increase was mainly due to Shigella sonnei; rates of infection with Shigella flexneri remained relatively constant. Trends showed marked differences between age groups and between ethnic groups. In comparison, the rates in the United States--much lower than those in Israel--began to decline in the early 1950s and have remained low. The incidence in Israel is now about 20 times higher than that in the United States. Thus shigellosis remains a major and growing public health problem in Israel, a country that has enjoyed a dramatic improvement in basic sanitary services and infrastructure over the past few decades. This disturbing finding lends urgency to efforts to control the disease.

Prospective study of the association between serum antibodies to lipopolysaccharide O antigen and the attack rate of shigellosis

A means for determining immune status against shigellosis would significantly improve the design and evaluation of interventional and other epidemiologic studies. Previous case-control studies have indicated the potential role of humoral antilipopolysaccharide antibodies. To test this proposition, 190 soldiers serving in a field unit were monitored prospectively for 2.5 months for shigellosis. Blood samples were taken at the beginning of the follow-up period and tested for serological evidence of prior exposure to Shigella sonnei and Shigella flexneri. The risk for acquiring S. sonnei shigellosis was 3.7 times higher for individuals lacking homologous antibodies (P less than 0.02). The risk for acquiring S. flexneri shigellosis was 2.4 times higher for individuals lacking antibodies, although a low attack rate for S. flexneri resulted in numbers too small to achieve statistical significance. While the importance of the serum antilipopolysaccharide antibodies in protection against the disease remains unclear, these findings demonstrate that they are strong markers of acquired immunity. Serological markers should be incorporated in epidemiologic studies of shigellosis and in the design and evaluation of future trials of potential anti-Shigella vaccines.

Probing of active site residues of the zinc enzyme 5-aminolevulinate dehydratase by spin and fluorescence labels

5-Aminolevulinate dehydratase from bovine liver requires Zn(II) for its activity and is inhibited by micromolecular concentrations of Pb(II). To elucidate the structure of the active site and its interactions between the active site and the metal binding site we labeled the active site for fluorescence studies and ESR spectroscopy. o-Phthalaldehyde reacted with active site lysyl and cysteinyl residues to form a fluorescent isoindole derivative. The fluorescence energy was independent of the deprivation of Zn(II) and of its substitution by the inhibitory Pb(II). For ESR-studies five iodoacetamide and four isothiocyanate pyrrolidine-N-oxyl derivatives with various spacer lengths were used to label the active site cysteinyl and lysyl residues, respectively. The ESR spectra of the modified enzyme preparations exhibited a significant immobilization of all labels, even with the longest spacers employed. Obviously the reactive cysteine is buried more than 12 A, and the active site lysine more than 11 A in a cleft of the enzyme structure. Zn(II) deprivation from the iodoacetamide spin-labeled enzyme caused a marked reversible increase in label mobility, whereas the Pb(II) substituted enzyme exhibited a smaller mobilization of the label. These results are interpreted by a model of the active site where the reactive cysteinyl and the lysyl side groups are close enough to be crosslinked by o-phthalaldehyde within a distance of 3 A. A structural role is assigned to Zn(II) in the enzyme, since Zn(II) deprivation does not alter the fluorescence of the isoindole derivative and increases the mobility of the cysteine-bound spin labels in the active site cleft.

Nasal carriage of Staphylococcus aureus: correlation with hormonal status in women

In view of recent observations on hormone-microorganism interactions, a study of Staphylococcus aureus nasal carriage in relation to sex-hormone status was undertaken. Prospectively in 479 women attending a colpocytologic clinic, hormonal status was assessed by determining the karyopyknotic index (KI) on smears stained by the Papanicolaou method. Rates of S. aureus nasal carriage were 29.3% in premenopausal women and 21.9% in postmenopausal women (P not significant). Carriage rates were significantly higher (P = .026, chi 2 7.32) for women with high KIs (40.7%) than for those with intermediate and low KIs (27.03% and 25.1%, respectively). S. aureus nasal carriage also correlated independently and significantly with previous antibiotic use and the presence of insulin-treated diabetes mellitus. This preliminary observation confirms an association between levels of sex hormones as reflected by the KI and S. aureus nasal carriage rates.

An in-use evaluation of decontamination of polypropylene versus steel bedpans

A prospective cross-over study in three different wards has demonstrated the lack of effect of two disinfectants compared with a detergent when added to the washing cycle of automatic bedpan washers that employ hot water centrally supplied at 60 degrees C. An unexpected and potentially important finding was that polypropylene pans were much more effectively cleaned and decontaminated than their stainless steel counterparts. The role, if any, of bedpans in the epidemiology of nosocomial infections remains a mystery. The continued absence of information clearly incriminating these ubiquitous devices in the transmission of potential pathogens, or of genes encoding antibacterial drug resistance, raises questions as to whether extensive efforts to achieve a high degree of decontamination of bedpans are necessary at all.

Pefloxacin versus ceftazidime in therapy of soft tissue infections in compromised patients

Soft tissue infections in compromised patients are frequently caused by Gram-negative organisms and particularly by Pseudomonas aeruginosa. These pathogens are effectively eradicated by pefloxacin as well as by ceftazidime. The effectiveness and safety of these two agents were compared in a prospective randomized study in 67 patients with soft tissue infections. Underlying conditions included malignant diseases, diabetes mellitus and chronic renal failure. The infections included: post operative infection, septic foot, soft tissue abscess and cellulitis. Thirty-three patients were treated with intravenous ceftazidime for a mean duration of ten days. More than half the 34 patients given pefloxacin were treated only orally for a mean period of 13 days. The clinical and bacteriological outcomes were similar in both groups. There was clinical cure or improvement in 26 pefloxacin cases and in 23 ceftazidime cases, failure in six pefloxacin cases and in seven ceftazidime and relapse in two pefloxacin and in three ceftazidime patients. The bacteriological responses were eradication in 23 pefloxacin cases and in 22 ceftazidime cases, persistence in five pefloxacin cases and in six ceftazidime cases, relapse in one pefloxacin case and in none of the ceftazidime group, reinfection in four pefloxacin cases and in three ceftazidime cases and there was one unassessed patient in the pefloxacin group and two in the ceftazidime group. Nausea and vomiting occurred in three patients and elevation of liver enzymes in another patient; all side effects were observed only in the pefloxacin treated patients. These results suggest that oral pefloxacin could offer an alternative to intravenous ceftazidime in half the compromised patients with tissue infections. However, adverse reactions due to pefloxacin administration should be watched for during such therapy.

Two different zinc sites in bovine 5-aminolevulinate dehydratase distinguished by extended X-ray absorption fine structure

The zinc coordination in 5-aminolevulinate dehydratase was investigated by extended X-ray absorption fine structure (EXAFS) associated with the zinc K-edge. The enzyme binds 8 mol of zinc/mol of octameric protein, but only four zinc ions seem sufficient for full activity. We have undertaken a study on four forms of the enzyme: (a) the eight-zinc native enzyme; (b) the enzyme with only the four zinc sites necessary for full activation occupied; (c) the enzyme with the vacant sites of (b) occupied by four lead ions; (d) the product complex between (b) and porphobilinogen. We have shown that two structurally distinct types of zinc sites are available in the enzyme. The site necessary for activity has an average zinc environment best described by two/three histidines and one/zero oxygen from a group such as tyrosine or a solvent molecule at 2.06 +/- 0.02 A, one tyrosine or aspartate at 1.91 +/- 0.03 A, and one cysteine sulfur at 2.32 +/- 0.03 A with a total coordination of five ligands. The unoccupied site in (b), obtained by taking the difference spectrum between the spectra from samples (a) and (b), is dominated by a single contribution of four cysteinyl sulfur atoms at 2.28 +/- 0.02 A. Spectra from samples (c) and (d) show only small changes from that of (b), reflecting a slight rearrangement of the ligands around the zinc atom.

Rapid screening of urine for bacteria and cells by using a catalase reagent

Five hundred urine samples were tested for cells and bacteria by using a commercial dipstick, a catalase screening device, standard culturing, and chamber counts. The sensitivities of the catalase test were 83% for all samples and 97.6% for specimens containing significant numbers of leukocytes and bacteria. The catalase screening test is simple to perform and should prove useful for the detection of urinary tract infections.

Effects of intravenous fat infusion on neonatal neutrophil and platelet function

Intravenous fat (Intralipid) is used extensively as a major component of parenteral nutrition for patients in the neonatal intensive care unit. Abnormalities of polymorphonuclear leukocyte (PMN) and platelet number or function related to Intralipid infusion have been reported although conflicting results exist. In order to examine potential adverse hematologic effects of Intralipid, 10 ill neonates were studied before and after a 16-hr infusion of 1 g/kilo of Intralipid. PMN count, chemokinesis, chemotaxis, and aggregation were unchanged pre- and post intralipid infusion. Platelet count, bleeding time, and platelet aggregation were also unchanged. Similar results were obtained in vitro when neonatal and adult PMNs and platelets were incubated in Intralipid and their function analyzed. These findings suggest that short-term, low-dose Intralipid has no measurable impact on neonatal PMN or platelet activity and support its use in neonates even in the presence of infection or thrombocytopenia.

Apparent effect of immune serum globulin prophylaxis in the military on viral hepatitis incidence in the civilian population in Israel

Since 1969, extensive use of immune serum globulin in the Israel Defence Force for prophylaxis against hepatitis A virus (HAV) infection has produced a sharp decline in the incidence of the disease. However, it is not clear whether this policy has affected the susceptibility of Israeli adults to HAV infection. In this study, we examined the effect of the immunisation policy on the incidence of hepatitis A virus infection in the civilian population in the 15-44 year age group, which includes all those who have completed compulsory military service since vaccination was introduced. The incidence of viral hepatitis in the Jewish civilian population aged 15-44 increased by approximately 50% 3-4 years after the implementation of the immunisation policy. This rise was not seen in the non-Jewish population of the same age nor among Jews aged 45-64. These findings strongly suggest that the immunisation policy in the military prevents both clinical and sub-clinical disease, but has had the effect of producing more susceptible people at an older age in the civilian population.

Rise in the incidence of viral hepatitis in Israel despite improved socioeconomic conditions

The incidence of viral hepatitis (mostly type A) in Israel, an area highly endemic for the disease, was examined between 1951 and 1985. During a period of improved standards of living, the overall reported incidence of the disease increased. In the Jewish population, the age of peak incidence shifted from 1-4 y to 5-9 y; this change is compatible with improved sanitation. However, whereas the absolute incidence declined among children 1-4 y old, it doubled among those 5-9 y old over the same period. The peak incidence in the non-Jewish population remains in children 1-4 y old. One possible explanation for the rise in overall incidence is an increase in the ratio of clinical to subclinical infections due to a shift of peak incidence to an older age group. Seasonal patterns have persisted against a background of changing morbidity, with the maximal incidence from late summer to midwinter. An unexplained, consistent excess incidence among males is observed for all age groups.