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Biomedical subjects

J N Hanna

Publications and source records attributed to J N Hanna.

At least 19 recordsLinked to original sources
PubMed2000

Fulminant hepatitis A in indigenous children in north Queensland.

Since 1993, three Indigenous children in north Queensland have died of fulminant hepatitis A. Even if the children had been able to undergo liver transplantation, prolonged immunosuppressant therapy and the likelihood of opportunistic infections would inevitably have jeopardised any chance of long-term survival. As hepatitis A has become a leading infectious cause of death in young Indigenous children in north Queensland, hepatitis A vaccine has recently been introduced into the vaccination schedule for these children.

Child, Preschool↗
PubMed1999

Japanese encephalitis in north Queensland, Australia, 1998.

OBJECTIVE: To describe the circumstances of two cases of Japanese encephalitis (JE) in north Queensland in 1998, including one acquired on the Australian mainland. DESIGN: Serological surveillance of sentinel pigs for JE virus activity; serological surveys of humans and pigs and viral cultures of mosquito collections. SETTING: Islands in the Torres Strait and communities in the Northern Peninsula Area (NPA) and near the mouth of the Mitchell River in Cape York, Queensland, in the 1998 wet season (December 1997-May 1998). RESULTS: Sentinel pigs in the Torres Strait began to seroconvert to JE virus in February 1998, just before onset of JE in an unvaccinated 12-year-old boy on Badu island. By mid-April, most sentinel pigs had seroconverted. Numerous JE viruses were isolated from Culex annulirostris mosquitoes collected on Badu. In early March, a person working at the mouth of the Mitchell River developed JE. Serological surveys showed recent JE virus infection in 13 young pigs on a nearby farm, but not in 488 nearby residents. In NPA communities, sentinel pigs seroconverted slowly and JE viruses were isolated from three, but none of 604 residents showed evidence of recent infection. Nucleotide sequencing showed that 1998 JE virus isolates from the Torres Strait were virtually identical not only to the 1998 isolate from an NPA pig, but also to previous (1995) Badu isolates. CONCLUSIONS: JE virus activity was more widespread in north Queensland in the 1998 wet season than in the three previous wet seasons, but ecological circumstances (e.g., less intensive pig husbandry, fewer mosquitoes) appear to have limited transmission on the mainland. Nucleotide sequencing indicated a common source for the 1995 and 1998 JE viruses. Circumstantial evidence suggests that cyclonic winds carried infected mosquitoes from Papua New Guinea.

Adult↗
PubMed1999

The timeliness of notification of clinically suspected cases of dengue imported into north Queensland.

OBJECTIVE: Evaluate the timeliness of notifications by medical practitioners of clinically suspected dengue importations into north Queensland (NQ). Describe the features the disease and determine the likely duration of viraemia prior to implementating public health measures. METHOD: Since December 1994, the Tropical Public Health Unit (TPHU) has maintained a register of all imported cases of dengue into NQ. Only confirmed viraemic cases were included in the study. Timeliness of notifications was defined as the interval between the first medical consultation in NQ and notification to TPHU. An Epi info database was developed and used to analyse data. RESULTS: There were 31 confirmed dengue importations into NQ during the study period, including all four dengue serotypes. The largest source (39%) was Papua New Guinea. The median time for notifications was 5.5 days. Doctor notifications ranged from 0 to 21 days (median 2 days), remaining notifications range from 1 to 42 days (median 10 days) (p < 0.05). The mean duration of viraemia of public health importance was 7 days (2-12 days). CONCLUSIONS: Of concern, doctors failed to notify > 50% of suspected cases and only 26% of notifications were received within 48 hours. Notification delays led to prolonged viraemia of public health importance increasing the potential risk of secondary infections. IMPLICATIONS: General practitioners need to promptly notify all clinically suspected cases of dengue in travellers recently arrived in NQ. The TPHU intends to reemphasise to general practitioner the importance of timely notifications and develop an orientation package for new doctors.

Adult↗
PubMed1998

Two contiguous outbreaks of dengue type 2 in north Queensland.

OBJECTIVES: To investigate two outbreaks of dengue type 2 in north Queensland, one in the Torres Strait beginning in late 1996, the other in a Cairns suburb in early 1997. DESIGN: Epidemiological investigation of all laboratory-confirmed cases of dengue, entomological investigation of the local environment, and laboratory analysis of the isolated dengue viruses. MAIN OUTCOME MEASURES: Numbers of confirmed and of locally acquired cases; virus serotype; comparison of nucleotide sequences between viruses isolated from the two outbreaks; and Breteau Index (BI = number of containers with larvae of the mosquito vector Aedes aegypti found per 100 houses investigated) on the affected islands and in the Cairns suburb. RESULTS: There were 201 confirmed cases of dengue in the Torres Strait outbreak, which lasted nearly seven months, and seven confirmed cases in the Cairns outbreak, which lasted about nearly 11 weeks. Most (190) were confirmed as dengue type 2. Nucleotide sequencing of viruses isolated from the two outbreaks showed they were identical. Ae. aegypti breeding sites were very common on the five Torres Strait islands surveyed (BIs, 73-219--high risk), but less so in the Cairns suburb (BI, 23). The most common breeding sites were water storage reservoirs, particularly rainwater tanks, on the outer Torres Strait islands, discarded containers (such as plastic containers, buckets and tyres) on Thursday Island, and garden items (such as flowerpot bases and jars) in Cairns. CONCLUSIONS: The virus responsible for the Cairns outbreak was most probably introduced from the Torres Strait, whereas the virus responsible for the Torres Strait outbreak was imported from Papua New Guinea. Preventive strategies tailored to specific locations are needed to reduce breeding of Ae. aegypti in north Queensland, and the consequent risk of future outbreaks of dengue.

Adolescent↗
PubMed1998

Malaria and its implications for public health in Far North Queensland: a prospective study.

This prospective study's objectives were to describe the features of all episodes of malaria diagnosed in Far North Queensland (excluding the Torres Strait) and to assess how much of a threat they posed to the area's public health. Over a three-year period, 216 episodes of malaria were diagnosed (158 Plasmodium vivax and 68 P. falciparum infections). Most (82%) of the infections were acquired in Papua New Guinea (PNG). Approximately 70% of the episodes occurred in Australian citizens, about half of whom were in malaria-endemic countries for work; the remainder travelled abroad for recreation. Three-quarters of the Australian citizens with malaria had taken either no or inadequate prophylaxis. Australian citizens who had taken adequate prophylaxis were much less likely to develop P. falciparum than other types of malaria compared to those who took either no or inadequate prophylaxis (p = 0.01). Gametocytes were present in 121 (56%) of the episodes of malaria. Mosquito surveillance was carried out in response to 38 (31%) of these gametocytaemic episodes. Significant numbers of Anopheles farauti sensu lato mosquitoes were found close to the residence of a patient in 4 (11%) of these episodes. Only two occasions when local transmission could have possibly occurred were recognised. We do not believe malaria poses an important threat to the health of the public in Far North Queensland. Nevertheless, it remains an important problem for those who travel abroad to malarious areas.

Adolescent↗
PubMed1998

The vaccination status of aboriginal and Torres Strait Island children in far north Queensland.

A survey was undertaken to ascertain the vaccination status of all 773 Aboriginal and Torres Strait Island children who were born and remained in Far North Queensland during the 1993-94 financial year. Only 42% had received all 15 vaccines scheduled in the first two years of life by their second birthday. More who resided in remote communities were fully vaccinated (64%) by then than those who lived in rural towns (32%) or an urban setting (21%) (p < 0.01). The 445 children who were not fully vaccinated required a median of three vaccines to have been fully vaccinated by the second birthday. Of these, 146 (33%) required only one vaccine, nearly 60% of whom would have been fully vaccinated if they had had the fourth (18-month) dose of diphtheria-tetanus-pertussis (DTP) vaccine. Of the 445, 143 (32%) required five or more vaccines to have been fully vaccinated. Only 26% and 36% of the children received all the vaccines scheduled at six and 12 months of age, respectively, on the same day. However, the eventual uptakes of the three vaccines scheduled at six months of age were very similar (approximately 80%) and simultaneous vaccination with the two vaccines scheduled at 12 months of age would have made a very limited (approximately 4 percentage points) impact on the overall percentage of fully vaccinated children. Considerably more than simple and apparently logical strategies will be required to ensure that Indigenous children in Far North Queensland are adequately vaccinated. A systematic approach, with a careful understanding of the barriers to routine vaccination and a means of prospectively tracking the vaccination status of each child, will be needed if state and national vaccination goals are to be met.

Age Factors↗
PubMed1997

Airport malaria in Cairns.

We report a patient with Plasmodium vivax malaria that was acquired in Cairns in October 1996. Rather than being "introduced" (i.e., derived from an imported case), we believe this is likely to have been a case of "airport malaria" (i.e., acquired from an infected mosquito imported in an aircraft). It is, to our knowledge, the first report of airport malaria in Australia.

Adult↗
PubMed1997

Further observations on the immune response to recombinant hepatitis B vaccine after administration to aboriginal and Torres Strait Island children.

OBJECTIVE: To determine the prevalence of markers of hepatitis B virus (HBV) immunity and infection at 5 years of age in Aboriginal and Torres Strait Island children who were fully vaccinated in infancy, and to examine the response to a booster dose of hepatitis B vaccine in those children who had no detectable immunity despite vaccination. METHODOLOGY: A cross-sectional study of serological markers to HBV in a sample of 239 Aboriginal and Torres Strait Island children, with a mean age of 5.7 years, who were fully vaccinated in infancy. The antibody response to a booster dose of hepatitis B vaccine was determined in those children in the sample who had no markers of either immunity to HBV or infection with HBV. RESULTS: Of the 239 children, 6% (95% CI 4-10%) had been infected and, of these, four were HBV surface antigen (HBsAg) positive. Of the remaining 224 children, only 41% (95% CI 35-48%) had evidence of immunity (i.e. an antibody to HBV surface antigen (anti-HBs) level of > or = 10 miu/mL) to HBV. Of the children with no detectable immunity (i.e. anti-HBs < 10 miu/mL), 113 were followed up after receiving a booster dose of hepatitis B vaccine. Of these, 84% (95% CI 76-90%) had an anamnestic response (i.e. anti-HBs < 10 miu/mL following the booster dose). Therefore 16% (95% CI 10-24%) still had no detectable immunity following the booster dose. CONCLUSIONS: This study provides further evidence that Aboriginal and Torres Strait Island children have a suboptimal response to recombinant hepatitis B vaccine. It also indicates that a considerable number of Aboriginal and Torres Strait Island children in the study age cohort have been exposed to HBV. However, despite these concerns, this study and historical data provide strong evidence that there has been a marked reduction in the prevalence of HBV infection and carriage in previously 'high risk' Aboriginal and Torres Strait Island children since the introduction of hepatitis B vaccines. Aboriginal and Torres Strait Island children who have been fully vaccinated in infancy do not require a booster dose of hepatitis B vaccine at school entry.

Australia↗
PubMed1997

Salmonella meningitis in children in far north Queensland.

Seven cases of Salmonella meningitis have occurred in infants in Far North Queensland since 1982. The mean age of onset was 2.8 months, and at least five of the cases were caused by Salmonella virchow. Five of the cases had significant complications during the acute illness: all required prolonged (median 34 days) inpatient management, and four developed permanent neurological sequelae. S. virchow is the serovar most frequently isolated from infants in Far North Queensland. The source of S. virchow infections in these infants remains uncertain, but transmission may occur through cross-infection and person-to-person transmission in the home.

Female↗
PubMed1997

Pneumococcal vaccination: an important strategy to prevent pneumonia in Aboriginal and Torres Strait Island adults.

The objective of the study was to examine the appropriateness of the National Health and Medical Research Council (NHMRC) recommendations concerning pneumococcal vaccination for Aboriginal and Torres Strait Island adults. Laboratory surveillance of invasive pneumococcal disease identified 95 cases acquired by adults 15 years of age and over in Far North Queensland from 1992 to 1995. The most common diagnosis was pneumonia (77 per cent). Sixty-one cases (64 per cent) occurred in Aboriginal and Torres Strait Island adults, who acquired the disease at a younger age (mean 40 years) than did other adults (mean 50 years). Most (93 per cent) of the Aboriginal and Torres Strait Island adults had at least one of the pre-existing medical conditions in the NHMRC criteria for pneumococcal vaccination. The most common was 'alcohol abuse' (62 per cent). Fifty-three (93 per cent) of the pneumococcal isolates from the Aboriginal and Torres Strait Island adults who had pre-existing conditions were serotyped. Fifty (94 per cent) belonged to types included in the currently available pneumococcal vaccine. We conclude that the NHMRC recommendations for pneumococcal vaccination are appropriate, considering the pattern of invasive pneumococcal disease that occurs in Aboriginal and Torres Strait Island adults in Far North Queensland. Because pneumococcal vaccination can reduce the pneumonia-associated morbidity and premature mortality experienced by Aboriginal and Torres Strait Island adults, the vaccine should be offered routinely to those considered to be at risk, particularly young men who have recently begun to consume hazardous amounts of alcohol, and recently diagnosed diabetics.

Adolescent↗
PubMed1996

An outbreak of Japanese encephalitis in the Torres Strait, Australia, 1995.

OBJECTIVES: To determine the distribution of virus infection during an outbreak of Japanese encephalitis (JE) in the Torres Strait, and to describe the environmental factors facilitating the outbreak. DESIGN: Human and porcine serological surveys for JE virus activity throughout the Torres Strait, and mosquito and household surveys on the island of Badu. SETTING: The island of Badu (where the clinical cases occurred) and the other islands of the Torres Strait, Australia, during April-May 1995. RESULTS: The serological surveys identified recent JE virus infection among residents or domestic pigs on at least nine outer Torres Strait islands. A JE virus, confirmed by nucleotide sequencing, was isolated from two asymptomatic Badu residents. Virus isolations and mosquito surveys implicated Culex annulirostris as the major vector involved in the outbreak. There was prolific Cx. annulirostris breeding in a variety of water bodies close to and within the Badu community. Over half (53%) of the households kept pigs in pens, and many (63%) of the pigpens were situated near standing water; in 56% of these "wet" pigpens Cx. annulirostris was breeding. CONCLUSIONS: There was evidence of widespread JE virus activity throughout the outer islands of the Torres Strait. We suggest that migratory birds and/or wind-blown mosquitoes could have imported the virus into the Torres Strait from a focus of viral activity, possibly in Papua New Guinea, thereby initiating the outbreak. A combination of environmental factors, with large numbers of domestic pigs in close proximity to human dwellings and mosquito breeding sites, undoubtedly facilitated the outbreak on Badu.

Adult↗
PubMed1996

An outbreak of hepatitis A in an intensive care unit.

We describe an outbreak of hepatitis A that occurred in an Intensive Care Unit (ICU) in a regional hospital in North Queensland. Seven people were infected including two patients, two close contacts of the index patient and three ICU nursing staff. The index case was admitted with an overdose and multiple trauma; he was not suspected to be incubating hepatitis A. The outbreak was initiated as a result of inadequate precautions taken whilst handling the index patient's bile. Problems identified upon reviewing the outbreak were inadequate terminal cleaning of equipment, food consumption in the ICU and inadequate handwashing practices. Implementation and maintenance of standard infection control practices is vital if further outbreaks of hospital-acquired hepatitis A and other enteric infections are to be avoided. We also suggest that the inactivated hepatitis A vaccine be considered for ICU staff.

Adult↗
PubMed1995

Invasive pneumococcal disease in central Australia.

OBJECTIVES: To document the incidence, case fatality, clinical and demographic features of invasive pneumococcal disease in central Australia. DESIGN: Invasive isolates from the regional central laboratory were prospectively recorded over five years and case notes retrospectively reviewed. Population denominators were calculated from national Census data from 1986 and 1991. RESULTS: The population estimates for the region were 14,568 for Aboriginals and 28,680 for non-Aboriginals. There were 185 episodes of invasive pneumococcal disease over the five years, 162 (87.5%) in Aboriginals and 23 (12.5%), in non-Aboriginals. The incidence in Aboriginal children under two years of age was 2052.7 per 100,000 and for those 20-59 years was 178.2 per 100,000. The relative risk in Aboriginals compared with non-Aboriginals was 10.8 (95% CI, 5.6-20.7; P < 0.0001) for those aged 0-4 years and 20.4 (95% CI, 9.7-42.5; P < 0.0001) for those 15-59 years. Forty-one Aboriginal adults aged over 14 (62%) had at least one conventional risk factor for pneumococcal disease; alcohol abuse was present in 27 (41%). There were 13 Aboriginal deaths and the case fatality rose from 2% in those under four years to 40% for those over 59 years. CONCLUSIONS: Central Australian Aboriginals have the highest incidence of invasive pneumococcal disease reported. The rate for children under two years is 59 to 80 times the rates for children in the United States and Sweden. These data have implications for improving vaccine use, health service delivery and environmental health in Aboriginal communities.

Adolescent↗
PubMed1995

An epidemic of acute post-streptococcal glomerulonephritis among aboriginal children.

OBJECTIVE: To describe an epidemic of acute post-streptococcal glomerulonephritis (APSGN) that occurred in Aboriginal children in three remote Aboriginal communities in Far North Queensland between July and October, 1993. METHODOLOGY: Children at the communities aged between 2 and 14 years were screened so as to identify all cases of APSGN. Parenteral penicillin was administered to all 583 children who presented for the screening procedure. RESULTS: APSGN was diagnosed in 58 (10%) of the 583 children. A further 142 (24%) children had microscopic haematuria. Children aged 5-8 years had the highest APSGN attack rate, and the highest prevalence of microscopic haematuria. Of all 583 children, 34% had skin sores, and group A streptococci (GAS) were isolated from 71% of the skin swabs. The prevalence of both skin sores and GAS were greater in the children with APSGN, and in those with microscopic haematuria, than in children with normal urine. A marked decline in the number of cases of APSGN occurred after the mass administration of penicillin. CONCLUSIONS: The epidemic of APSGN was associated with GAS skin infections. The mass use of penicillin may have had an effect in reducing the transmission of the nephritogenic strain of GAS. Microscopic haematuria was a significant finding in many of the children, and further prospective studies are required to understand the significance of this finding.

Acute Disease↗
PubMed1995

Immunity to hepatitis B, poliomyelitis and measles in fully vaccinated aboriginal and Torres Strait Island children.

OBJECTIVE: To determine the immunity to hepatitis B, poliomyelitis and measles in fully vaccinated Aboriginal and Torres Strait Island children in north Queensland. METHODOLOGY: A cross-sectional survey of immunity in a sample of children; 101 fully vaccinated Aboriginal and Torres Strait Island children, with a median age of 24.5 months, from 10 communities in North Queensland participated in this study. The main outcome measures were the prevalence of adequate antibody levels against hepatitis B, poliomyelitis and measles. RESULTS: Only 54% (95% CI 44-63%) of the children had adequate immunity (> or = 10 m iu/mL) to hepatitis B, and one child had been infected despite vaccination. Although all the children (95% CI 96-100%) had adequate immunity (i.e. neutralizing antibodies at a dilution of > or = 1:8) to poliovirus 2, only 93% (95% CI 86-96%) and 60% (95% CI 50-69%) had adequate immunity to polioviruses 1 and 3, respectively. Nearly all (96%; 95% CI 90-98%) of the children had adequate immunity (i.e. detectable IgG antibody) to measles. CONCLUSIONS: Although a relatively low proportion of the children had adequate antibody levels against hepatitis B the clinical significance of this observation is uncertain. Further studies are needed to determine whether fully vaccinated Torres Strait Island children have been adequately protected and whether they require a booster dose of hepatitis B vaccine. A substantial proportion of fully vaccinated Aboriginal and Torres Strait Island children are inadequately protected against poliomyelitis, and therefore any such child with acute flaccid paralysis should be investigated fully for poliomyelitis. Vaccinated Aboriginal and Torres Strait Island children are well protected against measles, as are other Australian children.

Antibodies, Viral↗
PubMed1994

Childhood immunisation: factors associated with failure to complete the recommended schedule by two years of age.

This study aimed to determine the immunisation status of preschool-aged children attending formal child-care facilities in north Queensland, and to examine factors associated with failure to be completely immunised by two years of age. Child-care centres and kindergartens within the Cairns City and Mulgrave Shire local government boundaries were selected randomly with probability proportional to size, and 613 children (median age of 47.0 months) were selected randomly from the facilities. Only 60.3 per cent (95 per cent confidence interval (CI) 56.3 to 64.3) of the children were fully immunised by two years of age. Children who had not received any vaccines by three months of age (that is, 'late starters') were less likely to be fully up-to-date at two years of age than children who started on time (odds ratio (OR) 10.3; CI 5.2 to 20.9). Children without a parent-held immunisation record were less likely to be up-to-date at two years of age than those children with a parent-held immunisation record (OR 2.8; CI 1.9 to 4.0). With follow-up of late-starters, and with the simultaneous administration of overdue vaccines with vaccines given in the second year of life, the percentage of children up-to-date at 24 months of age could have increased from 60.3 per cent to 82.3 per cent (CI 79.1 to 85.5). The immunisation coverage rates were inadequate to prevent outbreaks of vaccine-preventable diseases. Innovative strategies will be required if the vaccine coverage rates are to be improved. The parent-held immunisation record is of fundamental importance to all these strategies.

Australia↗