Oral nystatin prophylaxis and neonatal fungal infections

BACKGROUND

The value of antifungal prophylaxis depends partly on the incidence of neonatal fungal infection. We compared the incidence of fungal infection in babies in neonatal units which do and do not give antifungal prophylaxis using oral nystatin.

METHODS

Prospective, multi-centre surveillance study from 1993 to 2006 of invasive fungal infection, defined as positive blood or cerebrospinal fluid culture, in babies <1500 g birth weight in neonatal units in Australia and New Zealand.

RESULTS

There were 118 episodes of invasive fungal infection in 14 778 babies <1500 g, an incidence of 0.80% (95% confidence interval (CI) 0.66 to 0.94%). All infections were due to Candida species, mostly C. albicans (74, 62.7%) and C. parapsilosis (39, 33.1%). The mortality was 16.5%. The incidence was 0.54% (0.38 to 0.70%) for babies <1500 g in units using selective or universal oral nystatin prophylaxis and 1.23% (0.84 to 1.62%) in units using no prophylaxis (p<0.001). The incidence of infection in babies <1000 g was 1.78% (106/5948) (95% CI 1.44 to 2.12%). The incidence was 1.23% (0.92 to 1.54%) for babies <1000 g in units using nystatin prophylaxis and 2.67% (1.97 to 3.37%) in units using no prophylaxis (p<0.001).

CONCLUSIONS

The incidence of neonatal fungal infection was low in Australia and New Zealand, even without antifungal prophylaxis. Antifungal prophylaxis with oral nystatin was associated with a significantly lower incidence of fungal infection compared with no prophylaxis.

Neonatal infections in Asia

OBJECTIVE

To study the epidemiology (including incidence, antibiotic sensitivity and mortality) of neonatal unit infections in countries in Asia.

METHODS

One year prospective study of neonatal infections in eight neonatal units in Asia.

RESULTS

There were 453 episodes of sepsis affecting 394 babies. Mortality from neonatal sepsis was 10.4%, with an incidence of 0.69 deaths/1000 live births. Group B streptococcus was the most common early-onset organism causing 38% of episodes of early-onset (<48 h old) sepsis, with a rate of 0.51 episodes per 1000 live births and a mortality of 22%. Gram-negative bacillary early-onset sepsis occurred at a rate of 0.15 episodes per 1000 live births with a mortality of 12%. There were 406 episodes of late-onset sepsis. The incidence was high at 11.6 per 1000 live births, and mortality was 8.9%. Coagulase-negative staphylococcus caused 34.1% of episodes, whereas Staphylococcus aureus caused only 5.4%. Gram-negative bacilli caused 189 episodes (46.6%). Only 44% of Gram-negative bacilli were sensitive to both gentamicin and a third-generation cephalosporin, whereas 30% were resistant to both antibiotics. Meningitis occurred in 17.2% of episodes of late sepsis, with a mortality of 20%.

CONCLUSIONS

The incidence of late-onset sepsis was higher in Asia than in resource-rich countries, but the organisms isolated and mortality were similar. Over half of all Gram-negative bacilli were antibiotic resistant.

Increased mortality among patients sustaining hip fractures requiring surgery in a district general hospital

Fractures of the femoral neck are a common condition the incidence of which continues to rise. Associated mortality remains very high and knowledge of factors contributing to this high mortality is crucial in understanding outcome for both patient and surgeon. A retrospective review of 1254 patients operated on for fracture neck of femur was conducted to identify mortality at 30 days, 90 days and one year. Age, type of fracture, sex and waiting time for surgery were evaluated along with mortality for 47 patients who sustained their fracture while already inpatients with other concurrent illnesses. Those patients who sustained an inpatient fracture were found to have significantly higher mortality at 30 days, 90 days and one year. We concluded that these patients represent a very high-risk group that needs special consideration in management of their fracture and concurrent medical condition to reduce their high mortality.

Unnatural selection: reducing antibiotic resistance in neonatal units

Antibiotic use selects for antibiotic resistant bacteria. This is an example of rapid Darwinian natural selection in action. It occurs in neonatal intensive care units with the use of parenteral antibiotics, and in the community with oral antibiotic use. A 10 point plan is put forward to reduce antibiotic resistance in neonatal units.

Recurrent parotitis of childhood

BACKGROUND

Recurrent parotitis (RP) of childhood is a rare condition of unknown aetiology, probably immunologically mediated.

OBJECTIVE

To review the clinical presentation, diagnosis and management of RP of childhood.

METHODS

Retrospective study from 1983 to 2004 of children diagnosed with RP of childhood at a tertiary children's hospital.

RESULTS

We identified 53 children, 37 (70%) male and 16 (30%) female. The age of onset was biphasic, with peaks at 2-5 years of age and at 10 years. The commonest symptoms were swelling (100%), pain (92.5%) and fever (41.5%). Symptoms usually lasted 2-7 days with a median of 3 days. The mean frequency was 8 episodes per year. The diagnosis was often delayed, >1 year in 70% of patients, maximum 8 years. The most common diagnoses, before the definitive diagnosis of RP, were mumps (21%), 'infection' (15%) and stones (11%). Sialogram (57%) and/or ultrasound (41%) showed sialectasis in 81% of patients. Over half the patients (54%) were given antibiotics at least once to treat the parotitis. Two children had hypogammablobulinaemia, one child had human immunodeficiency virus infection, and one child had Sjogren's syndrome. Two children had high titre antinuclear antibodies.

CONCLUSIONS

Recurrent parotitis had a biphasic age distribution. The major clinical features that distinguish it from other causes of parotid swelling are the lack of pus and recurrent episodes. A clinical diagnosis can often be confirmed by ultrasound. Antibiotics do not have a role in treatment. Affected children should be screened for Sjogren's syndrome and immune deficiency.

Mycoplasma pneumoniae infections in Australian children

OBJECTIVES

To describe the epidemiology, clinical features and outcome of Mycoplasma pneumoniae infection in children presenting to a tertiary children's hospital.

METHODS

Sixty-three month retrospective review of serologically diagnosed M. pneumoniae infections.

RESULTS

There were 76 children, 42 boys and 34 girls, mean age 6.3 +/- 3.5 years. The age group most commonly affected was 5-9 years, followed by children 1-5 years. More than half of the patients had failed to respond to antibiotics before referral. The commonest presentation was with cough and fever. Coryza, diarrhoea, vomiting, tachypnoea and recession were significantly more common in children less than 5 years than in children 5-15 years. Hospitalized patients were more likely than non-hospitalized patients to have respiratory distress with recession and wheeze. Radiographic findings were non-specific. Thrombocytosis was found in 29 (41.4%) of 70 children studied.

CONCLUSION

The clinical features of M. pneumoniae infection were different in children less than 5 years than in children aged 5-9 years. The presence of thrombocytosis in 40% of the cases has not previously been reported in children.

Early onset neonatal meningitis in Australia and New Zealand, 1992-2002

OBJECTIVES

To study the epidemiology of early onset neonatal bacterial meningitis (EONBM) in Australasia.

DESIGN

Prospective surveillance study, 1992-2002, in 20 neonatal units in Australia and New Zealand. EONBM was defined as meningitis occurring within 48 hours of delivery.

RESULTS

There were 852 babies with early onset sepsis, of whom 78 (9.2%) had EONBM. The incidence of early onset group B streptococcal meningitis fell significantly from a peak of 0.24/1000 live births in 1993 to 0.03/1000 in 2002 (p trend = 0.002). There was no significant change over time in the incidence of Escherichia coli meningitis. The rate of EONBM in very low birthweight babies was 1.09/1000 compared with the rate in all infants of 0.11/1000. The overall rate of EONBM was 0.41/1000 in 1992 and 0.06 in 2001, but this trend was not significant (p trend = 0.07). Case-fatality rates for EONBM did not change significantly with time. Birth weight <1500 g (odds ratio (OR) 7.2 (95% confidence interval (CI) 4.8 to 10.9)) and Gram negative bacillary meningitis (OR 3.3 (95% CI 2.2 to 4.9)) were significant risk factors for mortality. Sixty two percent of the 129 babies who died from early onset sepsis or suspected sepsis did not have a lumbar puncture performed.

CONCLUSION

The incidence of early onset group B streptococcal meningitis has fallen, probably because of maternal intrapartum antibiotic prophylaxis, without a corresponding change in E. coli meningitis. Gram negative bacillary meningitis still carries a worse prognosis than meningitis with a Gram positive organism.

The managerial duties of the nurse in charge of a unit in combating the spreading of HIV/AIDS

The charge sister has an essential role to play in combating the spreading of the HIV in the environment of the nursing unit. The HIV/AIDS dilemma is a reality in the health care environment. On a daily basis nurses is treating patients with the HIV. Through the basic conceptual framework of the management process, the charge sister can play her part and contribute in keeping the disease under control in her work environment. An explorative, descriptive study was done through a structured questionnaire with four open questions. This study was aimed at developing and formulating guidelines to be included in a policy to be used in the combating of spreading of HIV in the health care unit by the charge sister and her staff. The results indicate the absence of policy regarding the prevention of the spreading of the HIV, necessary for orientation and in service training of staff.

Comprehensive health assessment for newly arrived refugee children in Australia

Providing appropriate and responsive care to refugees from diverse backgrounds and with unique health needs is challenging. Refugee children may present with a wide range of conditions, which may be unfamiliar to health professionals in developed countries. Additionally, refugees may experience unfamiliarity with the Australian health system and distrust of authority figures and/or medical practitioners. This article provides an overview of the priority areas in health and health management for paediatric refugee patients for paediatricians as well as other relevant health care providers caring for this group. Specific issues covered include general health assessment, infectious diseases, immunization, growth and nutrition, oral health, development and disability, mental health and child protection. Comprehensive health assessment can assist in identifying children at risk of poor health and to provide them with timely and effective care, advocacy and appropriate referral.

Should routine childhood immunizations be compulsory?

Routine childhood immunizations are compulsory in a small number of countries, including the United States of America. Arguments used to justify making immunizations compulsory include enhancing the health of the community and treating as paramount the rights of the child to be protected against vaccine-preventable diseases. But compulsory immunization infringes the autonomy of parents to make choices about child rearing, an autonomy which we generally respect unless doing so seriously endangers the child's health. We present a historical review and ethics discussion on whether routine childhood immunizations should be compulsory. We conclude that, for both ethical and practical reasons, routine immunization should not be compulsory if adequate levels of immunization can be achieved by other means.

Staphylococcus aureus infections in Australasian neonatal nurseries

OBJECTIVE

To study the incidence and outcome of systemic infections with methicillin sensitive (MSSA) and methicillin resistant Staphylococcus aureus (MRSA) infections in Australasian neonatal nurseries.

METHODS

Prospective longitudinal study of systemic infections (clinical sepsis plus positive cultures of blood and/or cerebrospinal fluid) in 17 Australasian neonatal nurseries.

RESULTS

The incidence of early onset sepsis with S aureus, mainly MSSA, was 19 cases per 244 718 live births or 0.08 per 1000. From 1992 to 1994, MRSA infections caused only 8% of staphylococcal infections. From 1995 to 1998, there was an outbreak of MRSA infection, in two Melbourne hospitals. The outbreak resolved, after the use of topical mupirocin and improved handwashing. Babies with MRSA sepsis were significantly smaller than babies with MSSA sepsis (mean birth weight 1093 v 1617 g) and more preterm (mean gestation 27.5 v 30.3 weeks). The mortality of MRSA sepsis was 24.6% compared with 9.9% for MSSA infections. The mortality of early onset MSSA sepsis, however, was 39% (seven of 18) compared with 7.3% of late onset MSSA infection presenting more than two days after birth.

CONCLUSIONS

S aureus is a rare but important cause of early onset sepsis. Late onset MRSA infections carried a higher mortality than late onset MSSA infections, but babies with early onset MSSA sepsis had a particularly high mortality.

Should Australia introduce a vaccine injury compensation scheme?

At least a dozen countries or states in the world have introduced vaccine injury compensation schemes. This paper argues that the Australian Government should introduce such a scheme, which may reduce litigation, and may improve consumer and provider confidence. The most important justification, however, is an ethical argument from justice and equity: introduction of a vaccine injury compensation scheme acknowledges the unique situation that routine childhood immunization is a public health measure, given and accepted in good faith, that may occasionally damage the recipient.

Bacteraemia and antibiotic use in respiratory syncytial virus infections

AIMS

To examine the frequency of and risk factors for bacteraemia in children hospitalised with respiratory syncytial virus (RSV) infection; and to determine current use of antibiotics in hospitalised children with RSV infection.

METHODS

Retrospective study of all children, aged 0-14 years, admitted to a tertiary children's hospital with proven RSV infection over a four year period. Children with concurrent bacteraemia and RSV infection were identified, and risk factors examined for bacteraemia. The case notes of a randomly selected comparison sample of 100 of these RSV infected children were examined to assess antibiotic use and population incidence of risk factors for severe RSV infection.

RESULTS

A total of 1795 children had proven RSV infection, and blood cultures were sent on 861 (48%). Eleven (0.6%) of the 1795 RSV positive children had bacteraemia. RSV positive children had a significantly higher incidence of bacteraemia if they had nosocomial RSV infection (6.5%), cyanotic congenital heart disease (6.6%), or were admitted to the paediatric intensive care unit (2.9%). Forty five (45%) of the random comparison sample of RSV infected children received antibiotics.

CONCLUSIONS

Bacteraemia is rare in RSV infection. Children with RSV infection are more likely to be bacteraemic, however, if they have nosocomial RSV infection, cyanotic congenital heart disease, or require intensive care unit admission.

Concurrent HIV infection and neuroblastoma

An infant is reported who presented with Pneumocystis carinii pneumonia, secondary to HIV infection, diagnosed at 3 months of age, and who had concurrent paravertebral neuroblastoma. Although neuroblastoma cell lines support the growth of HIV in vitro, this is the first report of a clinical association between HIV infection and neuroblastoma. Although we do not think the conditions are causally linked, we report the case to raise awareness of a possible association between HIV and neuroblastoma. The case also raises the importance of starting antiretroviral treatment with three drugs.

A ten year, multicentre study of coagulase negative staphylococcal infections in Australasian neonatal units

OBJECTIVE

To study late onset systemic infections with coagulase negative staphylococci.

METHODS

Prospective longitudinal study of coagulase negative staphylococcal infection in 18 Australasian neonatal nurseries.

RESULTS

From 1991 to 2000 inclusive, there were 1281 cases of coagulase negative staphylococcal (CoNS) sepsis, comprising 57.1% of all late onset infections. The male/female ratio was 1.27:1 (p < 0.05). The incidence of CoNS sepsis was 3.46 episodes per 1000 live births. Most infected babies (71%) were 24-29 weeks gestation at birth (mode 26 weeks). The first positive culture was day 7-14 in 49% of babies (mode 10 days). Five cases of meningitis were reported, an incidence of 0.4% of all CoNS infections. Twenty nine babies (2.3%) had concurrent necrotising enterocolitis and CoNS septicaemia. Four babies (0.3%) died from CoNS infection, but CoNS infection possibly contributed to the death of an additional 20 babies (1.6%). The mortality directly attributable to CoNS infection was significantly lower than that from late onset infections with Staphylococcus aureus (13.1%; relative risk (RR) = 36.1 (95% confidence interval (CI) 13.0 to 100.2) or with Gram negative bacilli (14.2%; RR = 45.5 (95% CI 16.8 to 123.3)).

CONCLUSIONS

CoNS are currently responsible for most late onset neonatal infections. Most infected babies are < 30 weeks gestation at birth, and usually present between 7 and 14 days of age. CoNS infections may be associated with necrotising enterocolitis, although causality is unproven. Neonatal CoNS infections are relatively benign: meningitis is rare and mortality low compared with infection from other organisms. Over-vigorous attempts to reduce the incidence of CoNS infections using prophylactic antibiotics are not advisable.

Carbohydrate-protein conjugate vaccines

Various pathogenic bacteria have coats of polysaccharide, many with repeating epitopes. Though polysaccharide vaccines have been available for some time, they induce mainly IgM production, and are only moderately protective in adults and ineffective in young children. It was originally shown in 1931 that the immunogenicity of polysaccharides could be enhanced by conjugating to a protein. The last two decades have witnessed the production and clinical testing of polysaccharide-protein conjugates specific for at least four different bacteria which normally cause considerable mortality and morbidity, especially in young children. In some cases, immunizing children from 4 months of age, with a booster early in the second year, has resulted in remarkably high success rates in protecting them from disease. For one pathogen, Haemophilus influenza type b, the success rate has been sufficiently high (> 95%) to suggest that this disease might, in time, be globally controlled in this way. The results of immunization with conjugate vaccines to Streptococcus pneumoniae, Neisseria meningiditis and Salmonella typhi are also very encouraging. More conjugate preparations are under development.

Interferon-gamma levels in nasopharyngeal secretions of infants with respiratory syncytial virus and other respiratory viral infections

Respiratory syncytial virus (RSV) infection, one of the most common causes of hospitalization of children in developed countries, has been implicated as a cause of asthma. We aimed to characterize the cytokine profile in nasopharyngeal aspirates (NPAs) taken from infants during upper respiratory tract infection to investigate whether RSV induced a unique immune response as compared with other viruses. Additionally, we sought to determine whether this profile was influenced by the infants' atopic status. A prospective birth cohort of babies at high risk of atopy was recruited. Ratios of a T-helper 1 (Th1) cytokine, interferon gamma (IFN-gamma) and a T-helper 2 (Th2)-like cytokine, interleukin-10 (IL-10), in NPAs were determined during episodes of respiratory tract infections in the first year. The viral aetiology of the respiratory tract infections was determined using polymerase chain reaction (PCR), culture and immunofluorescence. Atopic status was ascertained at 1 year of age using skin prick tests. Participants were recruited antenatally and subsequently followed in the community. Sixty babies with one or both parents atopic were enrolled into the study. IFN-gamma : IL-10 ratios in NPAs during upper respiratory tract infections and their correlation with viral aetiology and atopic status were the main outcome measures. The mean IFN-gamma : IL-10 ratio was significantly lower (due to lower IFN-gamma) during RSV infections than during infections with other viruses (P = 0.035). The cytokine ratio, however, did not differ between infants with or without wheeze during URTIs (P = 0.44), or between infants who were atopic or non-atopic (P = 0.49). This study suggests that RSV is associated with lower IFN-gamma production in young babies, regardless of their atopic status, compared to upper respiratory tract infections where either another virus is detected or where no viral identification is made.

Parent-requested treatment

The decision about EPO was referred to and made by the Drug Committee, a committee of physicians, nurses and pharmacists. This committee has perforce to make decisions about drugs and vaccines, decisions which sometimes have a significant ethical component due to concerns about cost, safety and efficacy. Our hospital is considering developing a Clinical Ethics Advisory Committee, to assist with difficult ethical decisions such as this one. Should such a committee be asked to make acute ethical judgements on patient management? Larcher describes his ideal Hospital Ethics Committee as nonprescriptive, and suggests a more appropriate role is retrospective analysis and reflective discussion of clinical ethical problems. Such discussion may help with future rather than current management issues, and can help support clinicians in their decisions and hospital staff in their management of patients.

Cost-effectiveness analysis of changing from live oral poliovirus vaccine to inactivated poliovirus vaccine in Australia

OBJECTIVE

Estimate the economic impact of introducing inactivated poliovirus vaccine (IPV) into the Australian childhood immunisation schedule to eliminate vaccine-associated paralytic poliomyelitis (VAPP).

METHODS

Cost-effectiveness of two different four-dose IPV schedules (monovalent vaccine and IPV-containing combination vaccine) compared with the current four-dose oral poliovirus vaccine (OPV) schedule for Australian children through age six years. Model used estimates of VAPP incidence, costs, and vaccine utilisation and price obtained from published and unpublished sources. Main outcome measures were total costs, outcomes prevented, and incremental cost-effectiveness, expressed as net cost per case of VAPP prevented.

RESULTS

Changing to an IPV-based schedule would prevent 0.395 VAPP cases annually. At $20 per dose for monovalent vaccine and $14 per dose for the IPV component in a combination vaccine, the change would incur incremental, annual costs of $19.5 million ($49.3 million per VAPP case prevented) and $6.7 million ($17.0 million per VAPP case prevented), respectively. Threshold analysis identified break-even prices per dose of $1 for monovalent and $7 for combination vaccines.

CONCLUSIONS

Introducing IPV into the Australian childhood immunisation schedule is not likely to be cost-effective unless it comes in a combined vaccine with the IPV-component price below $10.

IMPLICATIONS

More precise estimates of VAPP incidence in Australia and IPV price are needed. However, poor cost-effectiveness will make the decision about switching from OPV to IPV in the childhood schedule difficult.

The management of varicella-zoster virus exposure and infection in pregnancy and the newborn period. Australasian Subgroup in Paediatric Infectious Diseases of the Australasian Society for Infectious Diseases

Zoster immunoglobulin (ZIG) should be offered to pregnant, varicella-seronegative women with significant exposure to varicella-zoster virus (VZV) (chickenpox) infection. Oral aciclovir prophylaxis should be considered for susceptible pregnant women exposed to VZV who did not receive ZIG or have risk factors for severe disease. Intravenous aciclovir should be given to pregnant women who develop complicated varicella at any stage of pregnancy. Counselling on the risk of congenital varicella syndrome is recommended for pregnant women who develop chickenpox. ZIG should be given to a baby whose mother develops chickenpox up to 7 days before delivery or up to 28 days after delivery. Intravenous aciclovir should be given to babies presenting unwell with chickenpox, whether or not they received ZIG. Breastfeeding of babies infected with or exposed to VZV is encouraged. A mother with chickenpox or zoster does not need to be isolated from her own baby. If siblings at home have chickenpox, a newborn baby should be given ZIG if its mother is seronegative. The newborn baby does not need to be isolated from its siblings with chickenpox, whether or not the baby was given ZIG. After significant nursery exposure to VZV, ZIG should be given to seronegative babies and to all babies born before 28 weeks' gestation.

Acronymophilia: an update

The history, epidemiology, clinical features, and treatment of the epidemic infection, acronymophilia, a sinister scourge of modern medicine are described.

Is it Kawasaki disease?

Atypical cases of KD are common (up to 10% of the total) and the diagnosis should be considered without the full complement of diagnostic criteria. The risk of coronary dilation is high if IVIG is not given. Administration of IVIG is effective at preventing aneurysms, if given early. The high-risk groups for coronary artery disease are infants younger than 6 months of age and older children with very high platelet counts, high ESR and fever persisting for more than 2 weeks.

Critical influenza virus infection

OBJECTIVE

To determine the risk of death from influenza infection in children with chronic underlying disease.

METHODOLOGY

An 18-year retrospective study of children with 'critical' influenza A or B virus infection, defined as requiring admission to intensive care or resulting in death, but excluding laryngotracheobronchitis (LTB). Influenza infection was diagnosed by viral culture and/or immunofluorescence of respiratory secretions. Patients with LTB were analysed separately.

RESULTS

There were 27 cases of critical influenza virus infection over the study period, comprising 26 admissions to the intensive care unit (excluding LTB) and one death on the general wards. Thirteen (48%) of the 27 children had chronic underlying disease. In addition, 12 children with LTB were admitted to the intensive care unit. The LTB children were older and less likely to have chronic underlying disease. Nosocomial infection caused seven (26%) of the 27 critical infections. Nine (33%) of the 27 children with critical influenza died. Six (46%) of 13 children with chronic underlying disease and influenza admitted to intensive care died, compared with three of 14 (21%) without any underlying disease (odds ratio = 3.1, 95% confidence interval 0.6-14.0).

CONCLUSIONS

Critical life-threatening influenza virus infection was uncommon, but the mortality was high (33%), particularly in children with chronic underlying disease. Nosocomial infection with influenza was an important cause of admission to intensive care.

Comparison of influenza A and influenza B virus infection in hospitalized children

BACKGROUND

Influenza A and B viruses were cocirculating in Australia in the winter of 1997.

OBJECTIVE

To compare the clinical and demographic features of children with influenza A or influenza B virus infection admitted to a paediatric tertiary referral centre.

METHODOLOGY

Retrospective chart review of 91 hospitalized children with culture-proven influenza A or B virus infection during 1997.

RESULTS

Thirty-six (56%) of 64 children with influenza A were under 12 months of age compared with seven (26%) of 27 children with influenza B virus infection (P = 0.02). Influenza B virus infection was more common in children with underlying medical problems (P = 0. 01). Neurological manifestations were present in eight (12.5%) of 64 children with influenza A and none with influenza B virus infection (P = 0.09). There were no significant differences in signs and symptoms of children with influenza A and B virus infection, in severity of illness or in duration of hospital stay.

CONCLUSIONS

A greater proportion of children admitted with influenza A virus infection were under 12 months of age. Influenza B virus infection is associated more commonly with underlying medical disorders. It is not possible to differentiate between influenza A or B virus infection from presenting clinical signs and symptoms.

Differing serologic responses to an haemophilus influenzae type b polysaccharide-neisseria meningitidis outer membrane protein conjugate (PRP-OMPC) vaccine in australian aboriginal and caucasian infants - implications for disease epidemiology

This study compared Hib antibody responses to a single lot of PRP-OMPC vaccine given at 2, 4 and 12 months to 57 Aboriginal infants in rural areas of the Northern Territory and 56 Caucasian infants in Sydney, Australia. The Aboriginal infants had lower levels of antibody in cord blood (P>0.05), which were significantly lower (P<0.02) by 2 months of age. Antibody responses to one or two doses of vaccine, measured at 4 and 12 months of age, were similar but the geometric mean titre following the booster dose in Aboriginal infants was significantly lower (1.98 vs. 6.04 mcg/ml, P = 0.002). Low preimmunisation antibody is consistent with the early onset of Hib disease in Aboriginal infants before immunisation. Lower responses to boosting could correlate with persistence of Hib colonisation in indigenous populations.