Hepatitis A and B immunization for individuals with inherited bleeding disorders.

Hepatitis A and B vaccines are highly effective tools that can greatly reduce infection risk in the bleeding disorder population. Although hepatitis A and B immunization for individuals with bleeding disorders is universally recommended, various advisory bodies often differ with respect to many practical aspects of vaccination. To review the published literature and guidelines and form a practical, comprehensive and consistent approach to hepatitis A and B immunization for individuals with bleeding disorders. We reviewed published immunization guidelines from North American immunization advisory bodies and published statements from North American and international haemophilia advisory bodies. A search of the MEDLINE database was performed to find original published literature pertaining to hepatitis A or B immunization of patients with haemophilia or bleeding disorder patients that provided supporting or refuting evidence for advisory body guidelines. Various advisory bodies' immunization guidelines regarding individuals with bleeding disorders have contradictory statements and often did not clarify issues (e.g. post vaccination surveillance). Published literature addressing immunization in bleeding disorder patients is sparse and mostly examines route of vaccine administration, complications and corresponding antibody response. Although the risk of hepatitis A and B infection is low, the use of simple measures such as vaccination is reasonable and advocated by haemophilia advisory bodies. Following our review of the available literature and North American guidelines, we have developed comprehensive and practical recommendations addressing hepatitis A and B immunization for the bleeding disorder population that may be applicable in Bleeding Disorder clinics.

Congenital cytomegalovirus infection. Is there a breakthrough?

QUESTION: My 26-year-old patient is planning her first pregnancy in the coming month. She works in a day-care centre. Recently, two cases of cytomegalovirus (CMV) infection were diagnosed in her class. What tests should she have before and during the pregnancy, and how should I care for her? ANSWER: Cytomegalovirus infection, the most common congenital viral infection in humans, carries high risk of long-term morbidity and mortality. Seronegative mothers of children in day-care centres are at as high risk of acquiring the infection as day-care workers themselves. The immune status of at-risk patients should be evaluated as pregnancy progresses. Evidence of fetal infection does not necessarily mean fetal disease or damage. With a primary-infected fetus, termination of pregnancy might be discussed with the parents.

The morbidity and mortality of pediatric splenectomy: does prophylaxis make a difference?

PURPOSE: The aim of this study was to analyze the incidence of postsplenectomy sepsis morbidity and mortality after prophylaxis, in comparison with our previous 13-year study (1958 to 1970, inclusive). METHODS: All patients who had splenectomy at the Hospital for Sick Children, Toronto, between 1971 and 1995, inclusive (to give a minimum of 2 years for follow-up), were reviewed for infection and mortality. The criterion for classifying a patient as "infected" was the recovery of an invading encapsulated organism from the blood culture in a patient admitted to the hospital. RESULTS: Of the 264 patients studied, 10 had a postsplenectomy infection (3.8%); nine occurred in patients who underwent splenectomy between the ages of 0 and 5 years. Infection took place within 2 +/- 3 years (mean +/- SD) after splenectomy for the immunized patients and 11 +/- 5 days (mean +/- SD) for the nonimmunized children. A significant number of patients were admitted for an apparent respiratory infection, but no serum organisms were isolated. One died of overwhelming sepsis, but the responsible organism was not identified. CONCLUSION: Although there has not been a decrease in the number of splenectomies performed per year, the incidence of infection and mortality has decreased by 47% and 88%, respectively, with prophylaxis.

Congenital rubella syndrome. How can we do better?

QUESTIONMy 22-year-old patient immigrated to Canada 6 years ago from a country where there are no routine immunizations. She is now at 10 weeks' gestation and was exposed to a child with rubella infection. Her immune status is unknown. Should I give her passive or active immunization? How should I follow her pregnancy? And what should I tell her about the risk for her fetus?ANSWERIf the exposure took place less than 1 week ago, blood should be sent for rubella antibody titre. If results are positive for IgG, she is immune and there is no risk for the fetus. If a patient's immune status is unknown and the time of exposure is uncertain, serum samples for rubella antibodies should be obtained 3 weeks apart. Detection of rubella-specific IgM in a sample will confirm recent infection. Your patient should be counseled about the potential risk for her fetus and referred to high-risk pregnancy clinic for follow up. If seroconversion does not take place, she requires immunization immediately postpartum before discharge from hospital.

Cost of chickenpox in Canada: part I. Cost of uncomplicated cases.

OBJECTIVE: The purpose of this study was to assess the direct medical costs and productivity losses associated with uncomplicated chickenpox (no hospitalization) in Canada. METHODS: A total of 179 otherwise healthy 1- to 9-year-old children with active chickenpox were recruited from schools, day care centers, and physician offices in 5 provinces. Direct medical (physician contacts, medication, and diagnostic tests) and nonmedical (personal expenses including child care) resources expended during the illness were determined by caregiver interview. Productivity losses attributable to the disease were determined by assessing caregiver time lost from work and daily activities. Unit costs for all resources were obtained from sources in 2 provinces, and per-patient treatment costs were determined from the patient, Ministry of Health, and societal perspectives. RESULTS: From a societal perspective, the per-case cost for children from 1 to 4 years of age and from 5 to 9 years of age was $370.2 and $236.5, respectively. Direct medical costs accounted for 10% of the total costs in both groups. The largest cost driver in patient care was caregiver productivity losses, which amounted to $316.5 in the younger age group and to $182.7 in the older age group. Based on an estimated yearly incidence of 344 656 cases of uncomplicated chickenpox in Canada, the total annual societal burden of the disease can be estimated at $109.2 million, with a cost to the Ministry of Health of $11.2 million. CONCLUSION: Chickenpox is one of the last common childhood diseases prevalent in Canada, and the uncomplicated disease, despite its rather benign course, imparts a large annual economic burden.

Cost of chickenpox in Canada: part II. Cost of complicated cases and total economic impact. The Immunization Monitoring Program-Active (IMPACT).

OBJECTIVE: Primarily, to determine the direct medical costs and productivity losses associated with complicated chickenpox (hospitalized cases) and, secondarily, to quantify the overall economic burden of chickenpox in Canada. METHODS: Direct medical resource consumption patterns were determined by chart review of 160 otherwise healthy children and 40 children with leukemia hospitalized for chickenpox. Children were selected from the database of the Immunization Monitoring Program Active (IMPACT), a network of 11 tertiary-care hospitals in Canada that collected information at the time of hospitalization from January 1991 to March 1996. An additional 26 healthy children hospitalized were recruited prospectively by IMPACT. Productivity losses (time lost from work and daily activities) were assessed by caregiver interviews. Treatment costs were determined from the patient, Ministry of Health, and societal perspectives. RESULTS: The average societal per case cost for complicated chickenpox in healthy children was $7060 and $8398, respectively, from the retrospective and prospective assessments. For children with leukemia, the direct medical cost was estimated at $7228. These costs were combined with a cost established previously for uncomplicated chickenpox. The estimated yearly overall economic impact of chickenpox in Canada was $122.4 million, with $24.0 million attributable to Ministry of Health costs, assuming an estimated yearly incidence of 346 527 cases and a 0.54% rate of hospitalization for healthy children. CONCLUSIONS: Direct medical costs are the major cost driver in the care of complicated chickenpox. However, in the context of the overall economic burden of the disease, uncomplicated chickenpox is the major cost driver, contributing 89% to the total cost.

Congenital toxoplasmosis: prenatal diagnosis, treatment and postnatal outcome.

We report a female patient with congenital toxoplasmosis who presented with hydrops fetalis and cerebral abnormalities, detected on fetal ultrasound. Following prenatal treatment, the hydrops fetalis resolved and at four months of age she has normal growth and development. This case emphasizes the potential good prognosis in cases with congenital toxoplasmosis detected and treated prenatally.

Nosocomial infection following cardiovascular surgery: comparison of two periods, 1987 vs. 1992.

OBJECTIVE: To evaluate whether changes have occurred at our center in the rate of nosocomial infections and in the infectious organisms consequent to changes in policy and procedure as of 1987. SETTING: Multidisciplinary pediatric intensive care unit (PICU) in a major tertiary care center. DESIGN: Prospective comparative study. PATIENTS: Four-hundred and fifty-five consecutive patients who underwent cardiac surgery within a 10-month period. INTERVENTIONS: Changes related to antibiotic use and invasive device management were introduced after the 1987 survey. To determine the effect of these changes, all patients undergoing cardiac surgery between July 1991 and April 1992 were followed daily from PICU admission to 2 months after hospital discharge for signs of infection. Each infectious episode was reviewed by the nosocomial infection control committee. A weighted scoring system was used to determine risk. MEASUREMENTS AND MAIN RESULTS: In the 1987 study, 40 of 310 patients had 78 infections for a nosocomial infection ratio (NIR) of 25.2. Of the 455 patients surveyed in 1992, 72 had 91 episodes of infection. The nosocomially infected patient rate was 15.8 and the NIR was 20. The frequency of wound infection decreased from 7% in 1987 to 4.3% in this study, and no episode of mediastinitis was observed. In the bacteriological spectrum, the absence of candidal infection was significant, and there was a decrease in the proportional frequency of pseudomonas infection from 21% to 15%. CONCLUSION: The comparison between the two time periods demonstrates that an aggressive approach to managing intravascular catheters and urinary catheters and limiting the use of antibiotics probably affects the spectrum of nosocomial infections.

How long should someone wait after CMV infection to start pregnancy?

QUESTION: One of my patients contracted a primary cytomegalovirus (CMV) infection. What is the recommended waiting time between primary CMV infection and conception, and which tests are valid for determining whether infectivity is over? ANSWER: Although no data on the proper waiting period between primary CMV infection and conception are available, we suggest waiting until CMV-specific immunoglobulin G antibodies are present (at least 6 months).

Pseudobacteremia due to Pseudomonas fluorescens.

Pseudomonas fluorescens was recovered from 62 of 22,270 (0.26%) blood cultures, from 57 patients, over a 22-month period at a pediatric hospital. No illness was attributable to the blood culture isolate. A case-control study identified a significant correlation between the recovery of P. fluorescens in blood culture and concomitant coagulation studies (p less than 0.0001). In all cases blood for coagulation studies had been obtained at the same time as the blood culture. A review of venipuncture technique revealed that occasionally the coagulation study tubes (containing 3.8% sodium citrate) were being inoculated before blood culture bottles. P. fluorescens was subsequently isolated from coagulation tubes and from sodium citrate solutions prepared and dispensed in the hospital for use in coagulation studies. In vitro studies confirmed that sodium citrate solutions supported the growth of P. fluorescens, with preferential growth at 25 degrees C and 4 degrees C. This is the first description of P. fluorescens as a cause of pseudobacteremia. Pseudobacteremia was attributed to cross-contamination of blood cultures following inoculation of contaminated citrated collection tubes.

Q fever: hazard from sheep used in research.

The recent recognition that Q fever is endemic in Ontario and the known occupational risk of Q fever to research personnel working with sheep prompted a study to determine the prevalence of antibodies to the causative organism, Coxiella burnetti, in animals and staff at a Toronto animal research institute. Of 37 sheep 34 (92%) were found to be seropositive--that is, to have a titre of complement-fixing antibody to the phase II antigen of 1:8 or greater. Of 331 staff members tested, 18% were found to be seropositive, compared with 0.6% of a random sample of Toronto blood donors. The highest rate of seropositivity, 68%, was in the 28 animal attendants tested. Seropositivity was associated with working with sheep or fetal lamb tissue (p less than 0.0001) and with visiting the animal facility (p less than 0.001). Of the 59 seropositive staff members 63% had had no direct contact with sheep. There were 12 clinically apparent cases of Q fever, 2 of which required admission to hospital. Q fever remains a serious occupational hazard to staff working in research laboratories using sheep, even to those with indirect exposure to infected animals.

The management of central intravenous catheter infections.

Catheter-associated infection is a frequent complication in patients with indwelling intravenous catheters used for administration of total parenteral nutrition and/or cancer chemotherapy. Thirty-seven catheter-associated infections in 19 patients were identified in our retrospective survey conducted for the period from January 1, 1982, through December 31, 1982. Fourteen patients were receiving total parenteral nutrition for gastrointestinal disorders, and five were receiving total parenteral nutrition and chemotherapy for underlying malignancy. Coagulase-negative staphylococci were isolated from 65% of catheter-associated bacteremias, as a single species (18 cases) or as one of multiple species (6 cases). Ten of 33 coagulase-negative staphylococcal isolates (30%) were methicillin-resistant. Twenty-one infections (57%) were initially treated with antibiotics administered through the central venous catheter. There were three failures with this treatment; in two cases the catheter was removed because of continued fever and positive blood cultures despite antibiotics, and one patient developed a pyogenic granuloma. The remaining 18 (86%) catheter-associated infections were cured without catheter removal. However, a new infection occurred subsequently in two of these patients. We recommend that vancomycin and an aminoglycoside be the initial empiric therapy for suspected catheter-associated sepsis. Lack of defervescence or continued positive blood cultures for 2 to 4 days despite antibiotics are indications for catheter removal. Otherwise antibiotics should be continued for 14 to 21 days.