Trends in the Epidemiology of Campylobacteriosis in Israel (1999-2012).

The objective of this study was to examine the recent trends in the epidemiology of campylobacteriosis in Israel. A Sentinel Laboratory-Based Surveillance Network for Bacterial Enteric Diseases was established in Israel by the Israel Center for Disease Control (ICDC). This network generated data on subjects from whom Campylobacter spp. was isolated in community and hospital laboratories. Further characterization of the isolates was done at the Campylobacter National Reference Laboratory. Data from these two sources were integrated and analyzed at the ICDC. Between 1999 and 2012, 40,978 Campylobacter stool isolates were reported to the ICDC by the sentinel laboratories. The incidence rate of campylobacteriosis increased from 65.7 per 100,000 in 1999 to 101.7 per 100,000 in 2012. This increase resulted from a significant rise in the incidence of campylobacteriosis in the Jewish population which, since 2009, surpassed the consistent higher incidence of the disease in Israeli Arabs. The peak morbidity in Israel consistently occurred in late spring, with a risk excess in males compared with females, in younger age groups and earlier in the life span among Arabs than among Jews and others. These results suggest that further analytical studies should be carried out to identify risk factors responsible for the increased incidence of campylobacteriosis and better direct prevention and control of the disease in Israel.

A national survey of the molecular epidemiology of Clostridium difficile in Israel: the dissemination of the ribotype 027 strain with reduced susceptibility to vancomycin and metronidazole.

Our goals were to study the molecular epidemiology and antimicrobial susceptibilities of C. difficile strains in Israel. Microbiology laboratories serving 6 general hospitals (GH) and 10 long-term care facilities (LTCF) were asked to submit all stool samples in January-February 2014 that tested positive for C. difficile. Toxigenic C. difficile isolates were recovered in 208 out of 217 samples (95.8%), of which 50 (23.6%) were from LTCFs. Ribotype 027 was the most common type overall, identified in 65 samples (31.8%), and was the predominant strain in the 3 GHs with the highest incidence of C. difficile infections. Other common strains were slpA types cr-02 (n = 45) and hr-02 (n = 18). The proportions of vancomycin and metronidazole MIC values >2mg/L were high in ribotype 027 (87.7% and 44.6%, respectively) and slpA-cr-02 strains (88.8% and 17.8%, respectively). This study demonstrates that the ribotype 027 strain has disseminated across Israel and is now the most common strain.

Epidemiological, diagnostic, clinical, and therapeutic aspects of Brucella bacteremia in children in southern Israel: a 7-year retrospective study (2005-2011).

BACKGROUND: Data on the various aspects of brucellosis in children living in southern Israel are missing. OBJECTIVES: Our aim was to study the epidemiological, microbiological, diagnostic, clinical, therapeutic and outcome features of brucellosis in children <19 years of age in southern Israel during 2005-2011. PATIENTS AND METHODS: The study population included all patients hospitalized with a diagnosis of brucellosis, established according to a clinical presentation compatible with brucellosis+presence of Brucella bacteremia (BB). RESULTS: A total of 128 (50.8%) of 252 patients admitted with a diagnosis of brucellosis had BB (all with Brucella melitensis). All patients were of Muslim Bedouin ethnicity. The mean incidence of BB in southern Israel was 16 cases/100,000 Bedouin, with no significant changes during the study period. Overall duration of symptoms before diagnosis was 10.1±10.9 days. Fever at diagnosis was recorded in <20% of the patients. The most frequent symptoms were arthralgia (61.7%), weakness (32.8%), gastrointestinal disturbances (27.3%), myalgia (25%), and headache (18.8%). The main clinical findings included monoarthritis (36.7%), hepatosplenomegaly (25%), lymphadenopathy (17.2%), heart murmur (11.7%), and skin rash (9.4%), respectively. Anemia, leukopenia, thrombocytopenia, and pancytopenia were reported in 17.6%, 29.6%, 12.8%, and 2.3% of the patients, respectively. Twenty-nine (30.5%) patients with BB had serum agglutinin titers ≤1/160 (13, 13.7%%, had titers <1/160). Twenty-seven (93%) of the 29 patients aged 0-4 years were treated with gentamicin and trimethoprim-sulfamethoxazole; a total of 77 (60.2%) patients received gentamicin and doxycycline. CONCLUSIONS: Childhood brucellosis remains an important public health problem in southern Israel. BB was diagnosed in >50% of the children with brucellosis, and B. melitensis was identified in all cases. Arthralgia, weakness, and gastrointestinal complaints were the most common symptoms, and monoarthritis, hepatosplenomegaly, and lymphadenopathy were the most common clinical findings. A considerable number of patients with BB had undetectable/low serum agglutinin titers, suggesting insufficient reliability on serology alone in diagnosis of brucellosis.

A randomized, double-blind, placebo-controlled trial of selective digestive decontamination using oral gentamicin and oral polymyxin E for eradication of carbapenem-resistant Klebsiella pneumoniae carriage.

OBJECTIVE: To assess the effectiveness of selective digestive decontamination (SDD) for eradicating carbapenem-resistant Klebsiella pneumoniae (CRKP) oropharyngeal and gastrointestinal carriage. DESIGN: A randomized, double-blind, placebo-controlled trial with 7 weeks of follow-up per patient. SETTING: A 1,000-bed tertiary-care university hospital. PATIENTS: Adults with CRKP-positive rectal swab cultures. METHODS: Patients were blindly randomized (1 :1) over a 20-month period. The SDD arm received oral gentamicin and polymyxin E gel (0.5 g 4 times per day) and oral solutions of gentamicin (80 mg 4 times per day) and polymyxin E (1 x 10(6) units 4 times per day for 7 days). The placebo arm received oral placebo gel 4 times per day and 2 placebo oral solutions 4 times per day for 7 days. Strict contact precautions were applied. Samples obtained from the throat, groin, and urine were also cultured. RESULTS: Forty patients (mean age ± standard deviation, 71 ± 16 years; 65% male) were included. At screening, greater than or equal to 30% of oropharyngeal, greater than or equal to 60% of skin, and greater than or equal to 35% of urine cultures yielded CRKP isolates. All throat cultures became negative in the SDD arm after 3 days (P < .0001). The percentages of rectal cultures that were positive for CRKP were significantly reduced at 2 weeks. At that time, 16.1% of rectal cultures in the placebo arm and 61.1% in the SDD arm were negative (odds ratio, 0.13; 95% confidence interval, 0.02-0.74; P < .0016). A difference between the percentages in the 2 arms was still maintained at 6 weeks (33.3% vs 58.5%). Groin colonization prevalence did not change in either arm, and the prevalence of urine colonization increased in the placebo arm. CONCLUSIONS: This SDD regimen could be a suitable decolonization therapy for selected patients colonized with CRKP, such as transplant recipients or immunocompromised patients pending chemotherapy and patients who require major intestinal or oropharyngeal surgery. Moreover, in outbreaks caused by CRKP infections that are uncontrolled by routine infection control measures, SDD could provide additional infection containment.

Distribution, dynamics and antibiotic resistance patterns of Streptococcus pneumoniae serotypes causing acute otitis media in children in southern Israel during the 10 year-period before the introduction of the 7-valent pneumococcal conjugate vaccine.

OBJECTIVES: To determine the dynamics of serotype prevalence, potential coverage by pneumococcal conjugate vaccines (PCV) and antibiotic resistance patterns of Streptococcus pneumoniae causing acute otitis media (AOM) in children in southern Israel before PCV7 introduction in the routine immunization program in Israel. METHODS: All S. pneumoniae isolates from middle ear fluid from children with AOM during 1999-2008 were included. Prospectively collected demographic data on S. pneumoniae serotypes and antibiotic resistance patterns were analyzed. RESULTS: A total of 14,911 tympanocenteses yielded 5281 (35%) S. pneumoniae. Proportion of S. pneumoniae-AOM did not vary significantly (overall 35%; 33% in 2007; 38% in 2002 and 2003). The most frequent serotypes were 19F, 14, 23F and 19A; in both Jewish and Bedouin children; serotypes 6A and 19A contributed 6% and 10%, respectively, of all S. pneumoniae isolates. Serotypes included in PCV7, PCV10 and PCV13 represented 60%, 64%, 85% in Jewish children vs. 49%, 55% and 74%, respectively, in Bedouin children (P < 0.001). Nonsusceptibility to TMP/SMX decreased significantly, in parallel with a significant increase in the nonsusceptibility to erythromycin, clindamycin and in multidrug resistant (MDR) isolates. No changes were recorded in the proportion of S. pneumoniae isolates with penicillin MIC ≥ 1.0 µg/ml. The proportion of penicillin- and erythromycin-nonsusceptible and of MDR serotype 6A and 19A isolates increased significantly in Bedouin children. CONCLUSIONS: (1) No significant changes were recorded in the yearly proportions of serotypes 23F, 19F, 19A, 14 and 6A in both ethnic populations; (2) Potential coverage of the 3 PCVs was higher in Jewish children than in Bedouin children; (3) The relatively high coverage of macrolides- and multidrug-resistant S. pneumoniae by PCV13 and lack of increase in penicillin, erythromycin and multidrug nonsusceptibility among non-PCV13 isolates is encouraging.

Community-acquired complicated intra-abdominal infections in children hospitalized during 1995-2004 at a paediatric surgery department.

UNLABELLED: Information on the epidemiologic, clinical, microbiologic and therapeutic aspects of community-acquired complicated intra-abdominal infections in paediatrics is limited. The objectives of this study were to investigate the epidemiologic, clinical, microbiologic and therapeutic characteristics of community-acquired complicated intra-abdominal infections occurring in children aged 1 month-15 y. Medical charts and microbiology data of all children hospitalized with complicated intra-abdominal infections were retrospectively examined. Complicated intra-abdominal infections were defined as infections extending beyond the viscus of origin into the peritoneal space, with subsequent development of abscess or peritonitis. One hundred and twenty-three patients with complicated intra-abdominal infections (99/123, 80% >5 y of age) were included; 113 (92%) had complicated acute appendicitis. Twelve (10%) patients underwent computerized tomography-guided percutaneous drainage of periappendicular abscesses. The mean rate of complicated intra-abdominal infections among patients with complicated acute appendicitis was 10% without significant changes during the study years. Positive intra-abdominal cultures were recorded in 97/108 (90%) evaluable patients; 65/97 (67%) cases were characterized by mixed bacterial flora growth. One hundred and ninety pathogens (aerobes n=164, 86%; anaerobes n=26, 14%) were isolated. Escherichia coli was the most common pathogen (94 isolates, 57%). In vitro amoxicillin/clavulanate coverage of E. coli and Klebsiella spp was modest (81% and 86%, respectively). The ampicillin/gentamicin/metronidazole regimen was more appropriate in vitro than the amoxicillin/clavulanate regimen (3/80, 4% resistant pathogens compared with 8/43, 19%; p=0.02). Post-operative complications were recorded in 33/123 (27%) patients. Time until defervescence to < 37.5 degrees C was shorter in children with periappendicular abscess than in children with generalized peritonitis (6+/-4 vs 4+/-3 days; p=0.009). IN CONCLUSION: (1) most community-acquired complicated intra-abdominal infections occurred as a result of acute appendicitis; (2) the rate of complicated intra-abdominal infections among patients with acute appendicitis was low and without significant changes during the study period; (3) E. coli was the most frequently isolated pathogen; (4) amoxicillin/clavulanate provided only partial coverage for complicated intra-abdominal infection pathogens and should be used with caution in the empiric treatment of complicated intra-abdominal infections.

Dissemination of Kingella kingae in the community and long-term persistence of invasive clones.

BACKGROUND: Although Kingella kingae is being increasingly recognized as an important pediatric pathogen, our current understanding of the transmission of the organism is limited. The dissemination of K. kingae in the community was studied in 2 ethnic groups living side-by-side in Southern Israel. METHODS: Organisms recovered from oropharyngeal cultures, obtained from healthy young Jewish and Bedouin children during a 12-month period, were typed by pulsed-field gel electrophoresis and compared. RESULTS: Isolates from Bedouin children usually differed from those derived from Jews, confirming the relative social isolation of the 2 populations and the importance of close mingling in the spread of K. kingae. Significant clustering of genotypic clones in households and Bedouin neighborhoods was observed, indicating person-to-person transmission through intimate contact. Organisms detected in the study were identical to historical isolates recovered over the last 15 years from respiratory carriers and patients with bacteremia or skeletal infections. CONCLUSIONS: The present study demonstrates that children may be asymptomatically colonized in the respiratory tract by virulent K. kingae clones. The organism is transmitted from child-to-child through intimate contact. Some strains exhibit increased fitness and are maintained in the population for prolonged periods.

Clinical and laboratory aspects of Moraxella catarrhalis bacteremia in children.

Moraxella catarrhalis is an uncommon cause of bacteremia in children. We present 17 children with M. catarrhalis bacteremia. Most patients were <2 years old (76.4%), immunocompetent (82.3%), and had concomitant lower respiratory symptoms (76.5%). Moraxella catarrhalis bacteremia occurs in young immunocompetent children and is frequently associated with lower respiratory tract symptomatology.

Anti-amebic antibody activity in patients, determined with antigens prepared from virulent parasites (indirect hemagglutination assay and enzyme-linked immunosorbent assay).

BACKGROUND: The serology of amebiasis is affected by low sensitivity and specificity. OBJECTIVES: To evaluate the advantage of the indirect hemagglutination assay and enzyme-linked immunosorbent assay in the diagnosis of amebiasis, using Entamoeba histolytica soluble antigen (macerated amebic antigens) prepared from four different virulent isolates, continuously cultivated in the presence of the original enteric bacteria. METHODS: Using IHA and ELISA with MAA antigen we examined 147 sera samples from patients with gastrointestinal symptoms, and 11 sera from amebiasis cases (confirmed by microscopy and copro-antigen ELISA). RESULTS: Of 104 of the 147 (70.7%) symptomatic cases that were amebiasis positive by IHA, 81 (55.1%) were positive by MAA-ELISA. In addition, of 11 amebiasis cases confirmed by microscopy and copro-antigen ELISA, 7 (64%) were amebiasis positive by both tests. Four species of bacteria were isolated from the ameba cultures: Escherichia coli, Morganella morganii, Proteus mirabilis, and Streptococcus lactis. Elimination of the bacteria from the cultures by an antibiotics cocktail containing gentamicin, imipenem, piperacillin-tazobactam and vancomycin was the preferred method. Absorption of patients' sera to bacterial antigen prior to serological analysis had only a marginal effect. CONCLUSIONS: These results indicate a correlation of 61% between the ELISA developed in this study and the IHA tests in the diagnosis of amebiasis.

Antibiotic susceptibility, serotype distribution and vaccine coverage of nasopharyngeal and oropharyngeal Streptococcus pneumoniae in a day-care centre in St. Petersburg, Russia.

UNLABELLED: The objectives were to study serotypes and antibiotic susceptibility of Streptococcus pneumoniae carried by healthy children attending a day-care centre in St. Petersburg. S. pneumoniae colonization was investigated in 125 children aged 16-70 months. Antibiotic susceptibility was determined by E-test and disk diffusion. 83 S. pneumoniae cases were isolated in 75/125 (60%) children: 36/75 (48%) in the nasopharynx, 12/75 (16%) in the oropharynx and 27/75 (36%) in both. Carriage rates were 100%, 68%, 72%, 46% and 54% in children aged 12-23, 24-35, 36-47, 48-59 and >or=60 months, respectively. 97.6% of isolates were susceptible to penicillin. 61.4%, 32.5%, 19.3%, 16.7% and 6% isolates were non-susceptible to trimethoprim/sulfamethoxazole, tetracycline, clindamycin, erythromycin and chloramphenicol, respectively. 20.5% of isolates were multidrug resistant (MDR). 45% of isolates were of serotypes included in the 7-valent pneumococcal conjugate vaccine (7V-PCV); 64.9%, 56.8%, 32.4% and 27% of 7V-PCV serotypes were resistant to trimethoprim/sulfamethoxazole, tetracycline, clindamycin and erythromycin, respectively. The respective figures for MDR isolates were 100%, 94.1%, 70.6% and 76.5%; 76.5% of all MDR isolates were covered by 7V-PCV. IN CONCLUSION: 1) resistance to trimethoprim/sulfamethoxazole and tetracycline was high; 2) resistance to macrolides was higher than in other Russian regions; 3) 7V-PCV coverage was modest, but the vaccine may potentially reduce MDR-S. pneumoniae.

First national surveillance of susceptibility of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella spp. to antimicrobials in Israel.

In this 1st national surveillance study, the susceptibility pattern of 1011 consecutive isolates of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella spp. isolated from patients hospitalized in Israel hospitals, covering 62.3% of all general hospital beds in the country, was investigated. Proportion of susceptibilities (range among institutions, MIC(50)/MIC(90) in micrograms per milliliter) were to ertapenem 95.0% (88.8-100%, 0.19/0.75), imipenem 98.8% (88.8-100%, 0.25/0.38), meropenem 98.2% (90.0-100%, 0.06/0.19), piperacillin-tazobactam 59.1% (42.6-77.0%, 16/256), ciprofloxacin 17.2% (9.0-24.6%, 32/32), levofloxacin 17.8% (9.0-24.6%, 32/32), amikacin 74.5% (63.8-98.0%, 6/32), and gentamicin 19.3% (12.3-28.5%, 96/256). Coresistance, cross-resistance, and variability between institutions were high. Only carbapenems retain predicted activity against ESBL-producing E. coli and Klebsiella spp. across Israeli hospitals.

The many faces of human-to-human transmission of brucellosis: congenital infection and outbreak of nosocomial disease related to an unrecognized clinical case.

BACKGROUND: Because person-to-person transmission of brucellosis is exceptional, physicians who care for patients with this disease are not considered to be at increased risk. A woman in her 24th week of pregnancy who had received a diagnosis of placenta previa presented to the hospital with massive vaginal bleeding and hypovolemic shock, requiring performance of an emergency Cesarean delivery. Two physicians who assisted the surgical delivery developed culture-proven Brucella melitensis infection. The organism was also recovered from cultures of blood samples obtained from the mother and the premature newborn. The mother had been observed since early pregnancy because of an undiagnosed febrile hepatitis, but no specific tests for brucellosis had been performed. Retrospective testing of serum samples obtained at the onset of disease were positive for Brucella antibodies, indicating that the disease could have been diagnosed earlier. METHODS: Hospital records of the obstetric, intensive care, and surgical departments were examined to identify all staff members who took care of the mother and her offspring. The identified personnel were interrogated about exposure to potentially infective blood and fomites and were screened by blood cultures and serologic tests for Brucella species. RESULTS: An additional physician who assisted in the resuscitation of the newborn had a blood culture positive for B. melitensis and a positive result of a diagnostic serological test. Ninety-five other members of the hospital staff, who were potentially exposed to the organism, were found to be uninfected. CONCLUSIONS: Although rare, transmission of B. melitensis from patients to medical personnel may occur. Strict adherence to universal precautions, especially during performance of medical procedures characterized by massive blood exposure, should be reinforced.

Community-acquired bloodstream infections in children > one month old in southern Israel (1992-2001): epidemiological, clinical and microbiological aspects.

We studied the epidemiology, microbiology, clinical picture and outcome of community-acquired bloodstream infections (CABI) in children in southern Israel during 1992-2001. Information was collected prospectively by daily surveillance. CABI was diagnosed when a positive blood culture was reported in a patient discharged from the emergency room or during <48 h since admission if hospitalized. There were 1439 CABI episodes in 1396 children aged 1 month to 14 y. CABI incidence was 100/100,000 children with no increase during the study period. Risk of CABI was 3.8 times higher in a Bedouin than in a Jewish child. 1561 bacteria (793, 50%, gram-positive and 768, 49% gram-negative organisms, respectively) and 13 fungi were recovered. Most frequent gram-positive organisms were Streptococcus pneumoniae (509 isolates, 32% of all isolates, 64% of all gram-positive), Staphylococcus aureus (137, 9%, 17%) and Streptococcus pyogenes (46, 3%, 6%). Enterobacteriaceae spp. were the most frequent gram-negative pathogens (279, 18%, 36%), followed by Brucella (205, 13%, 27%). S. pneumoniae was the most common pathogen in children <12 months and 1-5 y age; Brucella was the most frequent pathogen in children >5 y of age. Coverage of 7-valent pneumococcal conjugated vaccine for CABI was 38.5%. 38 (2.7%) patients died; 16 cases were caused by S. pneumoniae.

Blood culture contamination in pediatric patients: young children and young doctors.

OBJECTIVE: The objective of this study was to assess the role played by the patient's age and physician's experience in determining the contamination rate of pediatric blood cultures. METHODS: The proportion of true-positive (isolation of a pathogen) and false-positive (isolation of a contaminant) results among blood cultures obtained by in-training physicians and experienced pediatricians from young children (aged 1-35 months) and older children (>or=36 months of age) and the value of a positive blood culture to predict a true-positive result were retrospectively determined. RESULTS: The odds of a positive blood culture to predict isolation of a true-pathogen was 0.366 only when the sample was obtained by an inexperienced physician and 0.523 when it was drawn by an experienced physician (P < 0.001), 0.419 when it was obtained from a young child and 0.429 when it was drawn from an older child (P = 0.781). The predictive value of a positive result for isolating a pathogen was significant higher when an experienced physician drew the blood culture regardless of the patient's age. CONCLUSIONS: Patient's young age and lack of experience of the physician who draws the specimen increase the risk of blood culture contamination. These results strengthen the need to improve the technical skills of young physicians.

Blastoschizomyces capitatus keratitis and melting in a corneal graft.

CASE REPORT: We present the first case, to our knowledge, of Blastoschizomyces capitatus keratitis and melting in a corneal graft. An 80-year-old man was treated for a large, severe corneal abscess and melting in the corneal graft of his right eye. Medical history was negative for hematologic disorders. Urgent penetrating keratoplasty was performed. COMMENTS: Corneal cultures grew B. capitatus. Systemic fluconazole and systemic and topical amphotericin B treatment were started. Three months after the last operation, no recurrence was observed and the graft remained clear. B. capitatus can rarely cause severe keratitis in patients even in the absence of hematologic disorders.

Nosocomial bloodstream infections in children and adolescents in southern Israel: a 10-year prospective study (1992-2001).

We studied the epidemiology, microbiology, clinical presentation and outcome of nosocomial bloodstream infections (NBI) in children and adolescents in southern Israel during 1992-2001. Information on NBI was collected prospectively by active surveillance. NBI was diagnosed when a clinically significant positive blood culture was drawn in a patient during >48 h after admission. 469 episodes occurred in 370 children and adolescents aged 1 m-18 y. The overall incidence of NBI was 5.3/1000 patients, with no increase during the study period. A significant decrease in NBI incidence was recorded at the neonatal intensive care unit (NICU) during 1997-2001 vs 1992-1996. The incidences of NBI at the paediatric ICU (PICU), paediatric wards and paediatric surgery departments (PSD) were 24.1, 2.8 and 2.5/1000 patients, with an increase in NBI cases at PICU and PSD during 1997-2001 vs 1992-1996. Of 661 pathogens, Gram-negative, Gram-positive and fungal organisms were isolated in 54.3%, 36.6% and 9.1% of cases, respectively. Enterobacteriaceae (34.6% of all isolates) were the most frequently isolated Gram-negative organisms. Enterococcus spp., coagulase-negative staphylococci and Staphylococcus aureus (9.5% of all isolates each) were the most frequently isolated in Gram-positive organisms. A significant increase was recorded in the incidence of NBI caused by Streptococcus pneumoniae and Pseudomonas spp. A significant decrease in the susceptibility of Enterobacteriaceae spp. to piperacillin, ceftazidime, gentamicin and ceftriaxone was recorded during the study period. 33 (8.9%) patients with NBI died.

Lack of evidence of transmission of Pseudomonas aeruginosa among cystic fibrosis patients attending health camps at the Dead Sea, Israel.

BACKGROUND: Transmission of Pseudomonas aeruginosa among cystic fibrosis patients attending health camps has been reported previously. OBJECTIVES: To determine the transmission of P. aeruginosa among CF patients during three winter camps in the Dead Sea region in southern Israel. METHODS: Three consecutive CF patient groups were studied, each of which spent 3 weeks at the camp. The patients were segragated prior to camp attendance: patients who were not colonized with P. aeruginosa constituted the first group, and colonized patients made up the two additional groups. Sputum cultures were obtained upon arrival, at mid-camp and on the last day. Environmental cultures were also obtained. Patients were separated during social activities and were requested to avoid social mingling. Isolates were analyzed by antibiotic susceptibility profile and by pulsed field gel electrophoresis. RESULTS: Ninety isolates from 19 patients produced 28 different fingerprint patterns by PFGE. Isolates from two siblings and two patients from the same clinic displayed the same fingerprint pattern. These patients were already colonized with these organisms upon arrival. Two couples were formed during the camp, but PFGE showed no transmission of organisms. All other patients' isolates displayed unique fingerprint patterns and were distinguishable from those of other attendees, and none of the P. aeruginosa-negative patients acquired P. aeruginosa during camp attendance. Environmental cultures were negative for P. aeruginosa. CONCLUSIONS: We were unable to demonstrate cross-infection of P. aeruginosa among CF patients participating in health camps at the Dead Sea who were meticulously segregated.