Stable germline transformation of the malaria mosquito Anopheles stephensi

Anopheline mosquito species are obligatory vectors for human malaria, an infectious disease that affects hundreds of millions of people living in tropical and subtropical countries. The lack of a suitable gene transfer technology for these mosquitoes has hampered the molecular genetic analysis of their physiology, including the molecular interactions between the vector and the malaria parasite. Here we show that a transposon, based on the Minos element and bearing exogenous DNA, can integrate efficiently and stably into the germ line of the human malaria vector Anopheles stephensi, through a transposase-mediated process.

Randomised controlled trial of an educational strategy to increase school-based adolescent hepatitis B vaccination

OBJECTIVES

This study aimed to evaluate a specifically designed hepatitis B education/promotion curriculum package as part of a successful hepatitis B vaccination delivery system to adolescents.

METHODS

A randomised-controlled trial was used to evaluate the effect of the curriculum package (or intervention) on uptake of vaccine. Schools were randomly selected from the metropolitan region of Melbourne to intervention (66 schools or 7,588 students) or control groups (69 schools or 9,823 students). Class teachers administered the intervention to students over 4 class periods before the vaccination course.

RESULTS

The difference in mean school uptake between intervention and control was small at 1-2% per dose. 95% confidence intervals around the differences were -5% to 2% per dose and not significant. Intervention schools taught an average of 7 items out of 12 from the curriculum package. Immunisation rates increased by 4-10% per dose between low and high implementation schools, but this trend was not significant. Impact evaluation demonstrated significantly greater knowledge of hepatitis B and vaccination among students in the intervention than the control group.

CONCLUSION

Hepatitis B vaccination of pre-adolescents was not increased by the implementation of a curriculum package that successfully increased knowledge and awareness of hepatitis B in a school-based vaccination program. Additional strategies directed at the education of parents, the cooperative role of schools and pro-active providers might also be required to maximise vaccine uptake in this age group.

Oral absorption of clarithromycin in acute illness and during convalescence in patients with community-acquired pneumonia

STUDY OBJECTIVE

To compare the extent of oral clarithromycin absorption in patients during an illness and in health.

DESIGN

Sequential two-phase prospective study including an acutely ill pneumonia phase (PP) and a subsequent convalescent phase (CP).

STUDY POPULATION

Patients >/= 18 years old with radiographically confirmed community-acquired pneumonia (CAP) who were admitted to the hospital.

METHODS

During both study phases, patients received one single 500-mg dose of oral clarithromycin. Serial blood samples were drawn over a 24-h period in order to characterize the plasma concentration-time curves. Area under the curve from zero to 24 h (AUC(0-24)), maximum plasma concentration (Cmax), and time to maximum concentration (Tmax) were determined for both clarithromycin and its metabolite, 14-hydroxyclarithromycin, and compared between the two phases.

RESULTS

Twelve patients completed both phases of the study. For clarithromycin, there was a significant increase AUC(0-24) (47.37 +/- 8.51 microg/h/mL vs 36.22 +/- 6.09 microg/h/mL) in favor of the PP. There were no significant differences detected with respect to Cmax (4.32 +/- 0.63 microg/mL vs 3.57 +/- 0.46 microg/mL), or Tmax (3.50 +/- 0.50 h vs 2.83 +/- 0.59 h) between PP and CP. For 14-hydroxyclarithromycin, the AUC(0-24) and Cmax were significantly higher (5.84 +/- 1.08 microg/h/mL vs 8.84 +/- 1.92 microg/h/mL; 0.42 +/- 0.08 microg/mL vs 0.76 +/- 0.23 microg/mL) in the CP as compared to the PP. Tmax remained unchanged.

CONCLUSION

The extent of absorption of oral clarithromycin was not diminished during an acute illness with CAP.

Toward Anopheles transformation: Minos element activity in anopheline cells and embryos

The ability of the Minos transposable element to function as a transformation vector in anopheline mosquitoes was assessed. Two recently established Anopheles gambiae cell lines were stably transformed by using marked Minos transposons in the presence of a helper plasmid expressing transposase. The markers were either the green fluorescent protein or the hygromycin B phosphotransferase gene driven by the Drosophila Hsp70 promoter. Cloning and sequencing of the integration sites demonstrated that insertions in the cell genome occurred through the action of Minos transposase. Furthermore, an interplasmid transposition assay established that Minos transposase is active in the cytoplasmic environment of Anopheles stephensi embryos: interplasmid transposition events isolated from injected preblastoderm embryos were identified as Minos transposase-mediated integrations, and no events were recorded in the absence of an active transposase. These results demonstrate that Minos vectors are suitable candidates for germ-line transformation of anopheline mosquitoes.

Global cDNA amplification combined with real-time RT-PCR: accurate quantification of multiple human potassium channel genes at the single cell level

We have developed a sensitive quantitative RT-PCR procedure suitable for the analysis of small samples, including single cells, and have used it to measure levels of potassium channel mRNAs in a panel of human tissues and small numbers of cells grown in culture. The method involves an initial global amplification of cDNA derived from all added polyadenylated mRNA followed by quantitative RT-PCR of individual genes using specific primers. In order to facilitate rapid and accurate processing of samples, we have adapted the approach to allow use of TaqMan real-time quantitative PCR. We demonstrate that the approach represents a major improvement over existing conventional and real-time quantitative PCR approaches, since it can be applied to samples equivalent to a single cell, is able to accurately measure expression levels equivalent to less than 1/100th copy/cell (one specific cDNA molecule present amongst 10(8) total cDNA molecules). Furthermore, since the initial step involves a global amplification of all expressed genes, a permanent cDNA archive is generated from each sample, which can be regenerated indefinitely for further expression analysis.

Global cDNA amplification combined with real-time RT-PCR: accurate quantification of multiple human potassium channel genes at the single cell level

We have developed a sensitive quantitative RT-PCR procedure suitable for the analysis of small samples, including single cells, and have used it to measure levels of potassium channel mRNAs in a panel of human tissues and small numbers of cells grown in culture. The method involves an initial global amplification of cDNA derived from all added polyadenylated mRNA followed by quantitative RT-PCR of individual genes using specific primers. In order to facilitate rapid and accurate processing of samples, we have adapted the approach to allow use of TaqMan real-time quantitative PCR. We demonstrate that the approach represents a major improvement over existing conventional and real-time quantitative PCR approaches, since it can be applied to samples equivalent to a single cell, is able to accurately measure expression levels equivalent to less than 1/100th copy/cell (one specific cDNA molecule present amongst 10(8) total cDNA molecules). Furthermore, since the initial step involves a global amplification of all expressed genes, a permanent cDNA archive is generated from each sample, which can be regenerated indefinitely for further expression analysis.

Immunisation uptake, services required and government incentives for users of formal day care

OBJECTIVES

To determine immunisation uptake in children attending formal day care prior to the introduction of certificates (state) and parent incentives (federal), and to document parent and child carers' attitudes to these strategies.

METHOD

In 1997, 60 child care centres and 300 family day carers in suburban Melbourne were randomly sampled. Immunisation dates, service use and preference, and views on government incentives were obtained from parents of children under three years of age.

RESULTS

From 2,454 eligible children, information was obtained for 1,779, of whom 84% (95% CI 82-86) were completely immunised. Low income (OR 1.8, 95% CI 1.2-1.9, p < or = 0.001) and larger family size (OR 1.8, 95% CI 1.2-2.7, p = 0.002) and only ever using a doctor (OR 1.6, 95% CI 1.1-2.3) was associated with incomplete immunisation. Main reasons for delaying immunisation were occurrence of minor illness and work commitments. Families would prefer immunisation services at Maternal and Child Health visits (39%), evening sessions (22%) and at day care (22%). Immunisation uptake could increase to 94% if those receiving Childcare Assistance (67%) immunised their children on time but would increase to 87% if these incentive only motivated those for whom Childcare Assistance was essential (15%). While 98% of day care co-ordinators and 71% of family day care co-ordinators documented immunisation status at commencement of child care, only 51% and 33% respectively regularly updated this information.

CONCLUSION

Providing client-focused, flexible immunisation services and government incentives and legislation may work together to boost immunisation levels for those in formal child care.

Sparfloxacin versus ciprofloxacin for the treatment of community-acquired, complicated skin and skin-structure infections

Fluoroquinolones have been shown to be effective in the treatment of complicated skin and skin-structure infections, in part because of their broad-spectrum antibacterial activity against causative pathogens that are resistant to older antimicrobial agents. We enrolled 603 adult patients (>58% male, >85% white) in a double-masked, double-dummy, randomized, multicenter trial to compare the efficacy and tolerability of sparfloxacin (400-mg loading dose followed by 200 mg once daily) with those of ciprofloxacin (750 mg twice daily) for 10 days in the treatment of community-acquired, complicated skin and skin-structure infections. The primary efficacy variable was clinical response, based on assessment of signs and symptoms, in the clinically assessable population. Patients in the sparfloxacin and ciprofloxacin groups were comparable with respect to demographic characteristics, underlying diseases, medical history, and laboratory test results. Wound infection was the most common diagnosis, and Staphylococcus aureus was the most frequently isolated pathogen. For the 475 clinically assessable patients, the clinical success rate (percentage of patients cured or improved) was 90.1% (210/233) with sparfloxacin and 87.2% (211/242) with ciprofloxacin. In this analysis (95% confidence interval [CI], -2.8 to 8.6) and the intent-to-treat analyses (95% CI, -4.2 to 6.2), results with sparfloxacin were statistically equivalent to those with ciprofloxacin (95% CI, -1 to 15.3). For bacteriologically assessable patients, eradication rates were 87.0% (141/162) with sparfloxacin and 79.9% (123/154) with ciprofloxacin (95% CI, -1 to 15.3). Eradication rates of S. aureus and coagulase-negative staphylococcal infections were 90.2% (101/112) with sparfloxacin and 77.9% (88/113) with ciprofloxacin. For patients with 2 or more pathogens at baseline (mixed infections), bacteriologic success was 87.6% for sparfloxacin and 77.9% for ciprofloxacin. Pseudomonas aeruginosa infections were eradicated or presumed eradicated in 71.4% (10/14) of sparfloxacin-treated patients and 87.5% (7/8) of ciprofloxacin-treated patients. Overall success rates in the bacteriologically assessable patients for sparfloxacin (84.6% [137/162]) and ciprofloxacin (78.6% [121/154]) were statistically equivalent (95% CI, -2.5 to 14.5). Tolerability was assessed in all patients who received study medication. The overall frequency of treatment-related adverse events was comparable in the 2 treatment groups (26.5% sparfloxacin, 23.3% ciprofloxacin). Drug-related adverse events involving the digestive system occurred in 7.1% of sparfloxacin-treated patients and 19.0% of ciprofloxacin-treated patients; photosensitivity reactions were reported in 11.1% of patients in the sparfloxacin group and 0.7% of patients in the ciprofloxacin group (P < 0.001). The mean change in QTc interval from baseline to the maximum on-treatment value was greater in the sparfloxacin group (9 milliseconds) than in the ciprofloxacin group (3 milliseconds) (P = 0.005; 95% CI, 0.002 to 0.010). The efficacy of sparfloxacin was comparable to that of ciprofloxacin in the treatment of community-acquired, complicated skin and skin-structure infections, including those caused by staphylococci, the most common pathogens. Sparfloxacin's once-daily regimen, high skin-tissue penetration, and improved activity against gram-positive cocci make it a therapeutic alternative to ciprofloxacin for patients who are not at risk for photosensitivity reactions or adverse events associated with prolongation of the QTc interval.

Evaluation of a national surveillance unit

AIM

The Australian Paediatric Surveillance Unit (APSU) facilitates national active surveillance of uncommon childhood conditions. This study assessed whether it fulfilled its objectives and satisfied criteria established by the Centers for Disease Control and Prevention (CDC) for evaluating surveillance systems.

METHODS

Anonymous questionnaires were sent to users of the system, individual studies were reviewed, and data were collected from independent sources.

RESULTS

Seven hundred and sixty six clinicians, 48 investigators, and 15 public health professionals responded to the questionnaires. Clinicians reported that the APSU was useful, 33% saying information provided by the APSU informed or changed their clinical practice. Most (88%) reported that completing monthly report cards was not a burden. Impact on policy development was limited by suboptimal dissemination of information to public health professionals. Flexibility and timeliness were limited by design. Estimated sensitivity of APSU studies ranged from 92% (congenital rubella) to 31% (drowning/near drowning). Positive predictive value of notified cases was over 70% for most studies.

CONCLUSION

The APSU fulfils most of its objectives and meets CDC criteria salient to these. Ways in which the APSU could be improved have been identified, as have methodological challenges and limitations in applying CDC guidelines to this type of unit.

A combined liquid Hib (PRP-OMP), hepatitis B, diphtheria, tetanus and whole-cell pertussis vaccine: uncontrolled preliminary clinical trial of immunogenicity and reactogenicity

We have conducted a preliminary uncontrolled clinical trial of the immunogenicity and reactogenicity of a new fully liquid pentavalent combination vaccination which incorporates a diphtheria, tetanus and whole-cell pertussis vaccine with Hib (PRP-OMP) and hepatitis B vaccines. Forty-five infants received three doses of the pentavalent vaccination at 2, 4, and 6 months of age, and then a fourth dose at 18 months of age. Subjects were bled prior to each vaccination, and a month after the third and fourth vaccinations. A 7-day diary card was used to record subject temperatures and other systemic and local clinical signs after each vaccination. After the third dose, 98% of subjects had anti-PRP titres above 1 microgram ml-1 (95%ci 88%, 100%). Following boosting, the geometric mean titre (GMT) rose a mean 27-fold (95%ci 19-fold, 38-fold) to 33 micrograms ml-1, and all subjects' titres (lower bound of 95%ci 92%) exceeded 1 microgram ml-1. For hepatitis B antibody, there was a GMT of 100 mIU ml-1 after the third dose, and 86% of infants (95%ci 73%, 95%) had antibody levels > or = 10 mIU ml-1. After the fourth dose, there was a mean 77-fold boost (95%ci 48-fold, 130-fold) to a GMT of 860 mIU ml-1 and 95% (95%ci 84%, 99%) of subjects had titres > or = 10 mIU ml-1. Diphtheria, tetanus, and pertussis antibody levels were all at acceptable levels after the first three doses and again after the fourth vaccination. The pentavalent vaccine was well tolerated at all administration times, and had a minor reactogenicity profile similar to DTPw alone as reported in previous studies. This study has provided preliminary evidence for both the safety and immunogenicity of the pentavalent vaccine given as a course at 2, 4, 6 and 18 months.

Randomised controlled trial of biofeedback training in persistent encopresis with anismus

BACKGROUND

Paradoxical external anal sphincter contraction during attempted defecation (anismus) is thought to be an important contributor to chronic faecal retention and encopresis in children. Biofeedback training can be used to teach children to abolish this abnormal contraction.

METHODS

A randomised controlled trial in medical treatment resistant and/or treatment dependent children with anismus using surface electromyographic (EMG) biofeedback training to determine whether such training produces sustained faecal continence. Up to four sessions of biofeedback training were conducted at weekly intervals for each patient. Anorectal manometry was performed before randomisation and six months later. Parents of patients completed the "child behaviour checklist" (CBCL) before randomisation and at follow up.

RESULTS

Sixty eight children underwent anorectal manometry and EMG. Of these, 29 had anismus (ages 4-14 years) and were randomised to either EMG biofeedback training and conventional medical treatment (BFT) (n = 14) or to conventional medical treatment alone (n = 15). All but one child were able to learn relaxation of the external anal sphincter on attempted defecation. At six months' follow up, laxative free remission had been sustained in two of 14 patients in the BFT group and in two of 15 controls (95% confidence interval (CI) on difference, -24% to 26%). Remission or improvement occurred in four of 14 patients in the BFT group and six of 15 controls (95% CI on difference, -46% to 23%). Of subjects available for repeat anorectal manometry and EMG at six months, six of 13 in the BFT group still demonstrated anismus v 11 of 13 controls (95% CI on difference, -75% to -1%). Of the four patients in full remission at six months, only one (in the BFT group) did not exhibit anismus. Rectal hyposensitivity was not associated with remission or improvement in either of the groups. Mean CBCL total behaviour problem scores were not significantly different between the BFT and control groups, but there was a significant improvement in CBCL school scale scores in the BFT group, and this improvement was significantly greater than that seen in the control group.

CONCLUSIONS

The result of this study, together with those reported in other controlled trials, argues against using biofeedback training in children with encopresis.

Immunogenicity and reactogenicity associated with an 18-month booster dose of a new diphtheria-tetanus-whole cell pertussis vaccine

OBJECTIVE

To establish safety and immunogenicity of a reformulated whole cell pertussis based diphtheria-tetanus-pertussis vaccine (DTPw) at the 18-month booster stage following a 2, 4, and 6-month primary immunization course.

METHOD

Open trial in suburban Melbourne in 100 healthy children initially recruited through maternal and child health centres. Thirty-five subjects were bled prior to vaccination, and 4-6 weeks after vaccination. A 7-day diary card was used to record subject temperatures and other systemic and local clinical signs.

RESULTS

The increase in antibody geometric mean titres (GMT) after boosting was 19.5-fold (95%ci 14.2, 27.2) for tetanus and 26.5-fold (95%ci 16.6, 42.4) for diphtheria. Pertussis antibody GMTs also all showed substantial increases following the booster, with mean fold changes in titre ranging from 7.3 (Agg2) to 31.3 (Fha). Seventeen percent of subjects (95%ci 10%, 26%) experienced axillary temperatures > or = 38 degrees C during the 24-h period following vaccination. Low rates of significant (> 25 mm) injection site redness (13%) and swelling (8%) were recorded at 24 h postvaccination.

CONCLUSION

This vaccine was well tolerated by children at 18 months of age, and showed substantial boosting of antibody to all components.

Is a paediatrician needed at all Caesarean sections?

OBJECTIVE

The need for a skilled neonatal resuscitator in the form of a paediatrician or paediatric registrar to attend a vaginal delivery or Caesarean section (CS) is not clearly defined. This study was undertaken in order to ascertain the level of resuscitation a neonate might require dependent on the delivery mode and type of anaesthesia used.

METHODOLOGY

We analysed the Tasmanian Obstetric Audit from 1980 to 1989 for the need for intubation and Apgar scores at 1 min of term singleton deliveries by the mode of delivery.

RESULTS

The number of singleton term deliveries was 64739. When the data were analysed annually there was a trend for a reduction in the need for intubation in CS deliveries during the first 5 years, although this was not paralleled by an improvement in Apgar scores. Thus the intubation rate data are also presented for the last 5 years of the study. The intubation rate, Apgar score at 1 min of < 4, and Apgar score at 1 min of > or = 4 < 7 for repeat CS under epidural anaesthesia were 0.55% (0.26% for 1985-89) 0.83% and 3.58%, respectively, with relative risks when compared with spontaneous normal vaginal delivery of 1.8 (1.2 for 1985-89), 0.7 and 0.5, respectively. The relative risk of these outcomes was higher than for normal vaginal delivery for all other modes of delivery including repeat CS under general anaesthesia.

CONCLUSION

It is concluded that a paediatrician or paediatric registrar is not required to routinely attend repeat CS under epidural anaesthesia, but should be present for repeat CS under general anaesthesia.

Vaccine preventable diseases and immunisations: a qualitative study of mothers' perceptions of severity, susceptibility, benefits and barriers

This study investigated mothers' perceptions of vaccine-preventable diseases and associated vaccines in terms of perceived susceptibility, severity, benefits and barriers. A purposive sampling strategy was used to choose mothers whose only or youngest child was completely, incompletely (behind the recommended immunisation schedule) or partially (parents chose or advised not to have a specific immunisation) immunised or had no immunisations. Semi-structured interviews found that complete immunisers believed the risk of vaccines was lower than the risk from disease and that the likelihood of contracting many of these diseases was low. Incomplete immunisers perceived vaccines to be less effective in preventing disease and were often confused about which diseases the vaccines would protect against. Non-immunisers were more concerned about unknown, long-term side effects of vaccines than the diseases. Many mothers who did immunise believed that preventing diseases was not always possible and for diseases such as measles, mumps and rubella, it was not always necessary nor desirable. Vaccines were perceived as placing stress on the immune system rather than strengthening it. Important themes relating to barriers to the decision to immunise were a lack of 'balanced', detailed information and poor communication between health providers and parents. The major barrier to timely, age-appropriate immunisations was the occurrence of minor illnesses in the target child or the family. This study found that many mothers were balancing the risks of immunising with the risks of not immunising and this must be taken into account, along with factors such as difficulties in obtaining immunisations.

Measles-mumps-rubella and hepatitis B vaccination uptake in adolescents: a survey in metropolitan Melbourne

OBJECTIVE

To measure the uptake of preadolescent measles-mumps-rubella (MMR) and adolescent hepatitis B vaccinations and assess the influence of certain demographic factors on the uptake of these vaccines.

DESIGN

Prevalence surveys of uptake rates of preadolescent (school Year 6; age 10-11 years) MMR and adolescent (school Year 9; age 13-14 years) hepatitis B vaccination.

SETTING

City of Darebin, an inner northern metropolitan region of Melbourne, 1996.

SUBJECTS

1160 Year 6 school students (580 boys) and 1102 Year 9 school students (548 boys).

INTERVENTION

School-based vaccination program administered by Darebin Council.

RESULTS

83% of Year 6 students were vaccinated with the MMR vaccine (84.1% of girls and 81.9% of boys). 71.6% of Year 9 students completed the full course of hepatitis B vaccination (68.9% of boys and 74.2% of girls). There was a higher uptake of MMR in non-government primary schools, but no other demographic factors (sex, economic status, non-English-speaking background, parental education, school class size) were associated.

CONCLUSIONS

These uptake rates do not meet National Health and Medical Research Council (NHMRC) recommendations. Further study is required to determine and quantify the factors that affect vaccination uptake in adolescence. Programs may then be developed to improve vaccination uptake.

School based bicycle safety education and bicycle injuries in children: a case-control study

OBJECTIVES

To evaluate possible benefits of a school based bicycle safety education program ("Bike Ed") on the risk of bicycle injury in children.

METHODS

A population based case-control study was undertaken in a region of Melbourne, Australia. Cases were children presenting at hospital emergency departments with injuries received while riding bicycles. Controls were recruited by calling randomly selected telephone numbers. Data were collected by personal interview.

RESULTS

Analysis, based on 148 cases and 130 controls aged 9 to 14 years, showed no evidence of a protective effect and suggested a possible harmful effect of exposure to the bicycle safety course (odds ratio (OR) 1.64, 95% confidence interval (CI) 0.98 to 2.75). This association was not substantially altered by adjustment for sex, age, socioeconomic status, and exposure, measured as time or distance travelled. Subgroup analysis indicated that the association was strongest in boys (OR 2.0, 95% CI 1.1 to 3.8), younger children, children from families with lower parental education levels, and children lacking other family members who bicycle.

CONCLUSIONS

It is concluded that this educational intervention does not reduce the risk of bicycle injury in children and may possibly produce harmful effects in some children, perhaps due to inadvertent encouragement of risk taking or of bicycling with inadequate supervision.

Pragmatic science: accelerating the improvement of critical care

Adapting practices that are described in the literature or used effectively in other critical care units provides an opportunity to improve the quality of critical care and reduce costs. Described in the literature are different techniques for the gradual withdrawal of mechanical ventilator support from patients during weaning from the ventilator. Phoebe Putney Memorial Hospital in Albany, GA used a systematic approach to adapt these techniques to improve the weaning process. This resulted in a reduction in the number of days patients were on a ventilator and a reduction in the ICU length of stay for patients with acute respiratory failure requiring mechanical ventilation.

Kawasaki disease in Australia, 1993-95

AIM

To describe the epidemiology, management, and rate of cardiac sequelae of Kawasaki disease in Australia.

DESIGN

Cases were notified to the Australian Paediatric Surveillance Unit, an active national surveillance scheme, from May 1993 to June 1995.

RESULTS

139 cases of Kawasaki disease were confirmed. In 1994, the annual incidence was 3.7/100,000 children < 5 years old. Sixteen children were not admitted to hospital. Coronary artery abnormalities were reported in 35 (25%) children. Two patients were diagnosed at postmortem examination. Sixty six per cent of patients were diagnosed within 10 days of onset and 81% of these received intravenous gammaglobulin within 10 days. Forty five of the notified children did not fulfil the study criteria because of streptococcal infection or insufficient clinical criteria. One child with streptococcal infection had coronary artery dilatation.

CONCLUSION

Diagnosis of Kawasaki disease was delayed beyond 10 days in one third of patients, and almost 20% of children who could have received gammaglobulin within 10 days did not. The distinction between Kawasaki disease, streptococcal infection, and other possible diagnoses is problematic in some children.

Paediatric slow-speed non-traffic fatalities: Victoria, Australia, 1985-1995

An important group of fatal incidents are slow-speed pedestrian non-traffic incidents to children, which account for 14% of accidental deaths from all causes in Victorian children under 5 years of age between 1985 and 1995, and 12% of pedestrian deaths of all ages. In Victoria, Australia, the database of the state Consultative Council on Obstetric and Paediatric Morbidity and Mortality was utilised to identify paediatric slow-speed pedestrian non-traffic-accident deaths in the local population. Additional data relating to the car and its driver, the child, and the circumstances of the incident were abstracted from records kept by the State Coroner and the Victorian compulsory third party traffic injury insurance organisation. Twenty eight Victorian children were identified who had died in one of three types of incident (driverless cars, child interacting with the vehicle and driver, and drivers who were unaware of the child's proximity). These incidents were more common in rural areas compared with urban, usually occurring at the child's home. The child was with or near an adult on all occasions. The vehicle was usually being driven by a relative, and was reversing in a higher proportion of 'unaware' incidents compared with the 'interactive' type. The association of 'off-road' family vehicles and trucks with these incidents appears to be increasing, especially in recent years. These findings suggest some countermeasures, including the separation of vehicle driveways from children's play areas, and object vicinity ultrasonic warning devices for vehicles.

Primary course immunogenicity and reactogenicity of a new diphtheria-tetanus-whole cell pertussis vaccine (DTPw)

OBJECTIVE

To establish safety, immunogenicity, and batch stability of a reformulated whole cell pertussis based diphtheriatetanus-whole cell pertussis (DTP) vaccine (nDTPw) compared to the currently marketed Australian DTPw vaccine (Triple Antigen) in a three dose 2, 4 and 6 month primary immunization course. Reformulation was necessary to make the DTPw vaccine suitable for combination with hepatitis B and Haemophilus influenzae b vaccines.

METHODS

Double blind randomized controlled trial in suburban Melbourne in 812 healthy infants recruited through maternal and child health centres, of whom 208 received Triple Antigen and 604 received nDTPw.

RESULTS

Results for both reactogenicity and immunogenicity were similar and were not significantly different for the three batches of nDTPw. No new, serious, or unexpected adverse effect was recorded. Nearly twice as many nDTPw infants experienced no general reaction to the third dose (18%) compared to Triple Antigen (11%, P = 0.06). An elevated temperature (> or = 38 degrees C axillary) occurred in about three out of 10 babies overall, with rates being slightly higher for both vaccines after the second vaccination. Local reaction rates were significantly less common for nDTPw on days 2 and 3 following each of the three vaccinations. After dose three, 30% of nDTPw subjects experienced no local reaction compared to 20% of Triple Antigen subjects (P = 0.015, 95% Cl on difference 2%, 19%). Swelling after doses one and three occurred in 30% and 24% of Triple Antigen subjects, compared to 23% (P = 0.07, 95% Cl diff 0%, 13%) and 14% (P = 0.017, 95% Cl diff 2%, 17%) of nDTPw subjects. Tenderness after doses two and three occurred in 80%, and 78% of Triple Antigen subjects, compared to 71% (P = 0.04, 95% Cl diff 1%, 17%) and 68% (P = 0.025, 95% Cl diff 2%, 19%) of nDTPw subjects. There was a significantly higher post immunization diphtheria antitoxin GMT (2.73 IU/mL) for Triple Antigen compared to nDTPw (1.89 IU/mL; P = 0.02), although no subject in either vaccine group had a tetanus or diphtheria antibody titre less than six times the protective level of 0.01 IU/mL following immunization. The nDTPw post immunization GMTs were significantly higher for Agg2, Fha, and pertactin compared to Triple Antigen geometric mean titres (GMTs).

CONCLUSION

nDTPw is a safe and immunogenic vaccine when compared to Triple Antigen. The reformulated vaccine is an acceptable replacement for the currently marketed formulation, and for evaluation as a component of future combination vaccines.

Reduction in paediatric burn admissions over 25 years, 1970-94

Objective–To describe trends in burn admissions to a large paediatric burn centre, between 1970 and 1994.

Methods–Hospital records of the Royal Children's Hospital burns unit were audited for the years 1970-94 (n=4992), statewide hospital admissions identified from the Victorian Inpatient Minimum Database for the period, 1987-94 (n=3353), and Victorian burn deaths ascertained from the Australian Bureau of Statistics (n=163), 1970-94.

Results–Between 1970 and 1994 there was a 66% reduction in the annual number of burn admissions to the Royal Children's Hospital, a similar reduction across the state, from 52.4 (95% confidence interval (CI): 48 to 57)/100 000 in 1987 to 34.5 (95% CI:31 to 38)/100 000 in 1994 (p<0.05), and over a 40% fall in the mortality rate. Reductions occurred for all types of burns: scalds 60%; flame burns 55%; and contact burns 70%, but at differing time periods corresponding to the introduction of product legislation, education programs, or changes in heating practices. There was no decline in beverage related scalds. The proportion of children admitted with severe burns increased over the 25 year period, probably reflecting changes in referral practice, while the average length of hospital stay steadily declined, independent of burn type or burn severity.

Conclusions–We believe these reductions reflect the effects of mandatory changes in sleepwear standards and regulations, modifications in heating practices, legislated improvements in the safety of household products, and to a lesser extent the effect of burn education prevention campaigns in the media, especially those directed towards hot water burn injuries among younger children.