Results
Vaccine preventable diseases
Introduction
This section summarises the national notification data for influenza and diseases targeted by the National Immunisation Program (NIP) in 2006. These include diphtheria, Haemophilus influenzae type b infection, measles, mumps, pertussis, invasive pneumococcal disease, poliomyelitis, rubella, tetanus and varicella (chickenpox, shingles and unspecified). Data on hepatitis B and meningococcal disease, which are also targeted by the NIP, can be found in this report under 'Bloodborne diseases' and 'Other bacterial infections'. Other vaccine preventable diseases (VPDs) presented in this report include hepatitis A and Q fever.
Major changes to the funded Australian NIP Schedule in November 2005 included:
- inactivated poliovirus vaccine (IPV) replaced oral poliovirus vaccine (OPV) for all age groups. All IPV-containing combination vaccines include diphtheria-tetanus-acellular pertussis (DTPa) antigens (i.e. quadrivalent vaccines) and some also include hepatitis B and/or Hib antigens (i.e. pentavalent and hexavalent vaccines). The specific combination vaccines administered at 2, 4, and 6 months of age vary between states and territories but all provide DTPa-IPV quadrivalent vaccine at 4 years of age.
- varicella vaccine was added to the NIPS as a single dose due at 18 months (for children born on or after 1 May 2004) or at 12–13 years of age.
In 2006, rotavirus (Rotateq® and Rotarix®) and human papilloma virus (HPV) (Gardasil®) vaccines were registered by the TGA and became available in the private market throughout Australia. In October 2006, the Northern Territory commenced a funded rotavirus immunisation program for infants. Both rotavirus and HPV vaccines were added to the funded NIP Schedule during 2007.
There were 22,240 notifications of vaccine preventable diseases in 2006 (16% of total notifications. This was significantly more than the 17,775 notifications of vaccine preventable diseases (VPDs) reported in 2005 due to the addition of varicella infections as notifiable diseases in 2006. Pertussis was the most commonly notified VPD (10,998, 49% of all VPD notifications). Numbers of notifications and notification rates for VPDs in Australia are shown in Tables 2 and 3.
Diphtheria
| Case definition – Diphtheria
Both confirmed cases and probable cases are reported. Confirmed case: Requires isolations of toxigenic Corynebacterium diphtheriae or toxigenic C. ulcerans. Probable case: Requires isolation of Corynebacterium diphtheriae or C. ulcerans (toxin production unknown) and pharyngitis/laryngitis or toxic symptoms OR clinical symptoms and epidemiological links with laboratory confirmed case. |
There were no cases of diphtheria reported in 2006. The last case of diphtheria reported in Australia was a case of cutaneous diphtheria in 2001, which was the only case reported since 1992. Immunity to diphtheria measured in a national serosurvey in the late 1990s in Australia, showed high levels in people aged less than 30 years and declining immunity with increasing age.12 High levels of immunisation are needed to protect Australians against diphtheria when travelling in the 21 countries where the disease is still prevalent (http://www.who.int/immunization_monitoring/en/globalsummary/timeseries/tsincidencedip.htm)
Haemophilus influenzae type b disease
| Case definition – Haemophilus influenzae type b
Only confirmed cases are reported. Confirmed case: Requires isolation of Haemophilus influenzae type b (Hib) from a sterile site OR detection of Hib antigen in cerebrospinal fluid consistent with meningitis. |
There were 22 notifications of Haemophilus influenzae type b (Hib) disease in 2006, a rate of 0.1 case per 100,000 population. This was 5 more cases than reported in 2005. Nine cases (41% of total) were in children aged less than 5 years and 3 were infants aged less than 1 year. There were 7 cases in males and 15 cases in females, (male:female ratio 0.46:1), unlike in 2005 when the ratio was 1.8:1 (Figure 39).
Figure 39. Number of notifications of Haemophilus influenzae type b infection, Australia, 2006, by age group and sex
Indigenous status was recorded for 18 of the 22 cases; 7 were Indigenous and 11 were non-Indigenous. The Hib notification rate was 1.4 cases per 100,000 in Indigenous people and 0.07 cases per 100,000 in non-Indigenous people; a ratio of 20:1. Between 2001 and 2005, Hib notification rates in Indigenous people have been between 4.6 and 8.6 times the rates in non-Indigenous people except in 2002 when the Indigenous rate was 25 times that of the non-Indigenous rate (Figure 40).
Figure 40. Notification rate of Haemophilus influenzae type b infection, Australia, 2001 to 2006, by indigenous status
Cases under the age of 15 years were eligible for Hib vaccination in infancy. Of the 13 cases in 2006, 4 were unvaccinated, 1 partially vaccinated and 8 were fully vaccinated. Four of the fully vaccinated cases aged 5 years or less had received 2 or 3 validated doses of vaccine and met the case definition for vaccine failure.
Australia now has one of the lowest rates of Hib in the world after nearly 20 years of Hib vaccination.13
Influenza (laboratory confirmed)
| Case definition – Influenza
Only confirmed cases are reported. Confirmed case: Requires isolation of influenza virus by culture OR detection of influenza virus by nucleic acid testing OR detection of influenza virus antigen from an appropriate respiratory tract specimen OR a significant increase in antibody levels, or IgG seroconversion or fourfold or greater rise in antibody titre or a single high titre antibody. |
Influenza notifications in 2006 were approximately one third lower than in 2005, and have been reported in detail separately.14 There were 3,159 reports of laboratory-confirmed influenza in 2006, a rate of 15.3 cases per 100,000 population. Notifications of influenza showed a peak in August (Figure 41).
Figure 41. Number of notifications of laboratory confirmed influenza, Australia, 2006, by month of onset
Peak rates in Queensland were substantially higher in August than in other states (174 cases per 100,000 population against 60 cases per 100,000 population for all Australia, Figure 42). Higher reporting rates in Queensland may be a product of the active promotion of influenza laboratory testing requests from general practitioners by public health authorities (Amy Sweeny, personal communication). There was an outbreak of influenza in an aged care facility in the Australian Capital Territory in November 200614 which accounts for the peak in notification rates (Figure 42).
Figure 42. Number of notifications of laboratory confirmed influenza, Australian Capital Territory, Queensland and Australia, 2006, by month of onset
There were 654 notifications in children aged less than 5 years (21% of all notifications). As in previous years, influenza notification rates were remarkably higher in children under 5 years compared with older age groups (notification rate of 51.3 cases per 100,000 population) (Figure 43). The rate was highest in those under 1 year of age (264 cases per 100,000 population) and declined progressively after that. The overall male to female ratio was 0.9:1.
Figure 43. Notification rate of laboratory-confirmed influenza, Australia, 2006, by age group and sex
In 2006, 3,088 (98%) influenza notifications had viral serotype data. Of these 72% (2,238) were influenza A, 26% (809) were influenza B and 1% (41) were mixed infections. A breakdown of influenza notification by virus type and jurisdiction is shown in Table 13.
Top of pageTable 13. Notifications of laboratory confirmed influenza, Australia 2006, by state or territory and type
Influenza type |
State or territory | Australia | |||||||
|---|---|---|---|---|---|---|---|---|---|
| ACT | NSW | NT | Qld | SA | Tas. | Vic. | WA | ||
| Influenza A | 72 |
420 |
28 |
1,223 |
34 |
36 |
354 |
71 |
2,238 |
| Influenza B | 8 |
150 |
12 |
406 |
55 |
10 |
66 |
102 |
809 |
| Influenza A & B | 0 |
35 |
0 |
5 |
0 |
0 |
1 |
0 |
41 |
| Influenza type unknown | 0 |
9 |
0 |
26 |
0 |
1 |
0 |
35 |
71 |
| Total | 80 |
614 |
40 |
1,660 |
89 |
47 |
421 |
208 |
3,159 |
Of 657 influenza virus isolates analysed at the WHO Collaborating Centre for Reference and Research on Influenza in 2006, 402 were A(H3N2), 24 were A(H1N1) strains and 231 were influenza B. Continued antigenic drift was seen within the A(H3N2) viruses from the previous reference strains (A/California/7/2004 and A/New York/55/2004) and drift was also noted in some of the A(H1N1)viruses from the reference strain A/New Caledonia/20/99. The influenza B viruses isolated were predominately of the B/Victoria lineage and similar to the reference vaccine strain B/Malaysia/2506/2004.14
Vaccination history was recorded in 405 cases; 50 were reported as vaccinated (31 of these were aged 65 years or older) and 355 were unvaccinated. Over 77% of Australians aged 65 years or older were vaccinated against influenza in 2006.14
Measles
| Case definition – Measles
Both confirmed cases and probable cases are reported. Confirmed case: Requires isolation of measles virus or detection of measles virus by nucleic acid testing OR detection of measles virus antigen OR IgG seroconversion or significant increase in antibody level or fourfold or greater rise in titre or detection of measles specific IgM antibody in a reference laboratory (except when vaccinated 8 days to 8 weeks prior to testing) OR clinical illness characterised by a maculopapular rash and fever and cough, coryza, conjunctivitis or koplik spots and epidemiological link to a laboratory confirmed case. Probable case: Requires detection of measles IgM antibody in other than an approved reference laboratory and clinical illness. |
There were 125 cases of measles (0.6 cases per 100,000 population) notified in 2006; a dramatic increase on the 10 cases notified in 2005 (<0.1 cases per 100.000 population), which was the lowest annual rate for Australia since national surveillance began in 1991 (Figure 44). The increase was largely due to a multi-state outbreak in April 2006.
Figure 44. Number of notifications of measles, Australia, 1996 to 2006, by month of onset
Cases were reported from all states and territories except the Northern Territory. There were 112 confirmed and 13 probable cases.
In 2006, there was a substantial increase in the number of cases in all age groups (Figure 45). There were 5 cases in children aged less than 1 year, 24 in those aged 1–4 years; 39 in the 5–14 years age group, 18 in the 15–24 years age group, 27 in the 25–34 years age group and 12 in those aged more than 35 years.
Top of pageFigure 45. Trends in notification rates of measles, Australia, 1999 to 2006, by age group
A multi-state outbreak of measles occurred in April 2006, and was associated with a touring Indian spiritual leader who visited Western Australia, New South Wales and Queensland. The index case(s) occurred in the unimmunised visitors and resulted in 82 cases, two-thirds of whom were unimmunised and only 7% of whom were fully immunised against measles.15 Measles virus genotyping indicated that the outbreak cases were all D8.
The World Health Organization Western Pacific Region has set the year 2012 as the target for the elimination of measles. Researchers at the National Centre for Immunisation of Vaccine Preventable Diseases report that by a number of criteria, Australia is close to, or has, achieved endemic measles elimination.16 These criteria include a low incidence of confirmed measles cases; a high proportion of the population receiving 2 doses of the measles-mumps-rubella (MMR) vaccine; serological evidence of high level immunity in the Australian population; absence of an endemic measles virus genotype; a high proportion of cases who acquired their infection outside Australia or linked to such cases; containment of outbreaks without re-establishing an endemic measles genotype and maintaining an effective reproductive number (Ro) of less than one.16
Mumps
| Case definition – Mumps
Only confirmed cases are reported. Confirmed case: Requires isolation of mumps virus or detection of mumps virus by nucleic acid testing or IgG seroconversion or significant increase in antibodies or a significant increase in antibody level, or a fourfold or greater rise in titre to mumps virus (except where there has been recent mumps vaccination) OR detection of mumps specific IgM antibody (in the absence of recent mumps vaccination) AND a clinically compatible illness characterised by swelling of the parotid or other salivary glands lasting 2 days or more without other apparent cause OR a clinically compatible illness AND an epidemiological link to a laboratory confirmed case. |
In 2006, there were 275 notifications of mumps (1.2 cases per 100,000 population), a small increase on the 241 notifications of mumps (1.2 cases per 100,000 population), reported in 2005. The number of mumps notifications has been increasing since 2004 (Figure 46).
Figure 46. Number of notifications of mumps, Australia, 2001 to 2006, by month of onset
Cases were reported from all jurisdictions except Tasmania, with the largest number of cases (154) in New South Wales. There were clusters of mumps cases reported in New South Wales in 2006.
There were cases in all age groups with the highest rates in the 25–29 years age group (4.2 cases per 100,000 population). Rates in young children aged less than 5 years remained low (0.5 cases per 100,000 population, 6 cases). In 2006, the male to female ratio of cases was 0.9:1 (Figure 47), which is a reversal of male preponderance seen in previous years, probably due to clustering of cases.
Figure 47. Notification rate of mumps, Australia, 2006, by age group
Trends in notification rates by age group for mumps (Figure 48) show a continued increase in the rates for the 25–34 and 5–4 years age groups and a small decline in the 15–24 years age group.
Top of pageFigure 48. Trends in the notification rate of mumps, Australia, 1999 to 2006, by age group
Information on vaccination status was available for 177 (64%) cases; 32 were recorded as fully vaccinated; 13 as partially vaccinated; 132 as unvaccinated and there was no information on the vaccination status of the remaining 98 (36%) cases.
The high rate of mumps in the 25–34 years age group probably represents a susceptible cohort of individuals who have not been immunised. Mumps vaccine was made available in Australia in 1980 for use at 12–15 months of age and was combined with the measles vaccine in 1982. Therefore, no childhood doses of mumps vaccine were available to most individuals in the 25–34 years age group. This cohort was also not targeted in the Measles Control Campaign in 1998 where the 2nd dose of MMR was offered to primary school aged children (5–12 years). Uptake of vaccination in older individuals from the 15–24 years age group was likely to be poor.
A similar pattern is seen in the United Kingdom and the United States of America where under-immunised young adult populations led to outbreaks of mumps in the 18–24 years age group in 2004/05 and 2006, respectively.17,18 The increase in notifications in 2005 and 2006 meant that the rates in Australia exceeded 1 cases per 100,000 population, a threshold for disease elimination and indicative of endemic mumps transmission in Australia.13
Pertussis
| Case definition – Pertussis
Both confirmed cases and probable cases are reported. Confirmed case: Requires isolation of Bordetella pertussis or detection of B. pertussis by nucleic acid testing OR seroconversion or significant increase in antibody level or fourfold or greater rise in titre (in the absence of pertussis vaccination) or a single high-titre IgA to whole cells or detection of B. pertussis by immunofluorescence AND clinical evidence (a coughing illness lasting 2 weeks or more or paroxysms of coughing or inspiratory whoop or post-tussive vomiting) OR clinical evidence AND epidemiological link to a confirmed case. Probable case: Requires clinically compatible illness. |
Pertussis is the most common vaccine preventable illness in Australia, with periodic epidemics occurring at intervals of 3 to 5 years on a background of endemic circulation. Rates are normally higher in late winter and spring, except from 2004 onward, when non-seasonal rates remained elevated compared with previous years (Figure 49).
Figure 49. Number of notifications of pertussis, Australia, 1996 to 2006, by month of onset
In 2006, 10,998 cases of pertussis were notified; a rate of 53.4 cases per 100,000 population. This was similar in number and rate to that reported in 2005 (11,197 cases, 55.1 cases per 100,000 population). In 2006, 10,559 (96%) were confirmed and 439 (4%) were probable cases.
Notification rates increased with age, with the highest notification rate in the 60–64 years age group (Figure 50). There were more cases among women (6,624) than men (4,362) with a male to female ratio of 0.7:1. The highest rate among women was in the 60–64 years age group (114.9 cases per 100,000 population) and the highest rate in men was in the 65–69 years age group (83.2 cases per 100,000 population).
Figure 50. Notification rate of pertussis, Australia, 2006, by age group and sex
Trends in the pertussis notification rate in different age groups are shown in Figure 51. In 2006, pertussis notification rates declined in all age groups except for the 60 year and over age group, where rates increased from 61.2 cases in 2005 to 77.7 cases per 100,000 population. In particular, the decline seen in the 10–19 years age group following the introduction of adolescent vaccination in 2004, continued in 2006. In 2006, 89% of pertussis cases were aged 20 years or over compared with 50% in 2000.
Top of pageFigure 51. Trends in the notification rate of pertussis, Australia, 2000 to 2006, by age group
Increases in rates of pertussis in Australia may be, in part, due to errors in diagnosis using serology. In October 2006, PanBio announced a major revision in the cut-off level for their pertussis serology tests. These kits were widely used in New South Wales. As a result, there was a sharp decline in pertussis notifications in the last months of 2006 (Figure 52).
Figure 52. Number of notifications of pertussis, Australia, 2005 to 2006, by week of onset and state or territory
Notification rates of pertussis varied considerably by geographic location (Map 5). The highest rates were reported from South Australia, New South Wales and the Australian Capital Territory. The trends in pertussis notification rates by month of diagnosis are shown for these 3 states and for Australia in Figure 53.
Top of pageMap 5. Notification rates of pertussis, Australia, 2005, by Statistical Division of residence
Figure 53. Notification rate of pertussis, Australian Capital Territory, New South Wales, South Australia, and Australia, 2003 to 2006, by month of notification
Invasive pneumococcal disease
| Case definition – Invasive pneumococcal disease
Only confirmed cases are reported. Confirmed case: Requires isolation of Streptococcus pneumoniae from a normally sterile site by culture or detection by nucleic acid testing. |
There were 1,443 notifications of invasive pneumococcal disease (IPD) in Australia in 2006, a rate of 7 cases per 100,000 population. Notification rates declined in 2006 by 14% nationally, with declines in all jurisdictions between 7% and 37%. The Northern Territory continued to have the highest notification rate (27 cases per 100,000 population) while Victoria had the lowest (5.4 cases per 100,000 population). The geographical distribution of IPD varied within states and territories, with the highest rates in central and northern Australia.
The highest rates of IPD notification in 2006 were in male adults aged 85 years or older (43.2 cases per 100,000 population, Figure 54). The male to female ratio of IPD cases was 1.3:1.
Figure 54. Notification rate for invasive pneumococcal disease, Australia, 2006, by age group and sex
Additional data were collected on cases of invasive pneumococcal disease in all Australian states and territories during 2006. Analyses of these data are reported separately.19
Poliomyelitis
| Case definition – Poliomyelitis
Both confirmed cases and probable cases are reported. Confirmed case: Requires isolation of wild-type poliovirus or detection of wild-type poliovirus by nucleic acid testing (confirmed in reference laboratory) and acute flaccid paralysis. Probable case: Requires acute flaccid paralysis not due to other causes as determined by the Polio Expert Committee. |
In 2006, no acute flaccid paralysis (AFP) cases due to wild poliovirus, vaccine-derived poliovirus (VDPV) or vaccine associated paralytic poliomyelitis (VAPP) were reported in Australia.
The WHO target for AFP surveillance in a polio non-endemic country is 1 case of AFP per 100,000 children aged less than 15 years. A total of 48 eligible AFP cases were notified in Australia between 1 January and 31 December 2006, giving an AFP rate of 1.2 cases per 100,000 population. The Polio Expert Committee (PEC) reviewed clinical and laboratory information on 43 of the 48 eligible AFP notifications. The PEC was unable to provide final classification for 5 AFP notifications due to insufficient clinical information. Hence the 2006 non-polio AFP rate, based on the 43 eligible cases classified by the PEC, was 1.1 per 100,000 children aged less than 15 years.
Since the inception of the Australian AFP surveillance system in 1995, the WHO AFP surveillance standard has only been achieved in 2000, 2001, 2004 and 2006. However, adequate faecal sampling remains well below the 80% target established by WHO with only 23% of eligible AFP notifications having 2 samples collected 24 to 48 hours apart and within 14 days of onset of paralysis.20
With the introduction of IPV into the standard immunisation schedule in Australia from November 2005, no further isolations of OPV strains of poliovirus are expected in Australian-born AFP cases without overseas travel. This was demonstrated in 2006, with the last reported laboratory isolations of a poliovirus occurring after 2 infants were vaccinated with OPV at the end of 2005.
In 2006, globally 2000 confirmed cases of wild poliovirus were reported to WHO.21 Four countries: Nigeria, India, Pakistan and Afghanistan, were considered to be endemic. Imported wild poliovirus was detected in 10 countries and active transmission of imported poliovirus occurred in 4 of those (http://www.polioeradication.org/content/general/casecount.pdf). Australia is at risk of importation of polio through visitors and migrants from polio endemic areas and requires AFP and laboratory surveillance to be timely and comprehensive.22
Rubella
| Case definition – Rubella
Both confirmed cases and probable cases are reported. Confirmed case: Requires isolation of rubella virus OR detection of rubella virus by nucleic acid testing OR IgG seroconversion or significant increase in antibody level or fourfold or greater rise in titre to rubella virus in the absence of recent rubella vaccination, OR detection of rubella specific IgM in the absence of recent rubella vaccination and confirmed in a reference laboratory. Probable case: Requires clinical evidence AND laboratory suggestive evidence OR epidemiological evidence. Laboratory suggestive evidence: In a pregnant patient, detection of rubella-specific IgM that has not been confirmed in a reference laboratory, in the absence of recent rubella vaccination. Clinical evidence: A generalised maculopapular rash AND fever AND arthralgia/arthritis OR lymphadenopathy OR conjunctivitis Epidemiological evidence: An epidemiological link is established when there is: 1. Contact between 2 people involving a plausible mode of transmission at a time when: a) one of them is likely to be infectious (about 1 week before to at least 4 days after appearance of rash) AND b) the other has an illness which starts within 14 and 23 days after this contact AND 2. At least 1 case in the chain of epidemiologically linked cases (which may involve many cases) is laboratory confirmed. |
In 2006, there were 59 notifications of rubella (0.3 cases per 100,000 population) an increase of 90% on the 31 notifications in 2005. In 2006, rubella cases were reported from New South Wales (37 cases), Queensland (12 cases), Victoria (6) and 2 cases each in South Australia and Western Australia. No cases were reported from other jurisdictions.
The overall male to female ratio of notified cases in 2006 was 1.2:1; but in the 25–29 years age group, the ratio was 2.3:1 (Figure 55). There was an overall predominance of males in notifications in 1999, 2002 and 2003.
Figure 55. Notification rate of rubella, Australia, 2006 by age group and sex
In Australia, populations at risk of rubella include young men who did not receive rubella immunisation in school based programs;23 migrant women who did not receive rubella vaccines in their countries of birth;24,25 and Indigenous women with inadequate immunity.26
There were more than 28,000 cases of rubella reported to the WHO Western Pacific Region office in 2005, which implies that rubella infections could be acquired by Australian travellers to neighbouring rubella endemic countries.
Figure 56 shows trends in rubella notification rates in different age groups, with a slight increase in rates in young adults in 2006, but otherwise continuing at the low levels seen since 2003.
Figure 56. Trends in notification rates for rubella, Australia, 1999 to 2006, by age group
There were no cases of congenital rubella reported in 2006. Altogether there were 22 cases of rubella notified from women of child bearing age (15–49 years) in 2006.
As for measles and mumps, Australia is approaching the elimination of endemic rubella with rates of reported disease less than 1 case per 100,000 population since 2002 (Table 4a). In 2004, the United States was declared free of endemic rubella based on epidemiological evidence; the absence of a circulating endemic rubella genotype; high rubella vaccine coverage; and serological evidence of high levels of population immunity and mass immunisation in the Pan American region.27 The WHO Regional Committee for Europe agreed in 2005 to eliminate measles and rubella by 2010. http://www.euro.who.int/vaccine/20030808_4
Brotherton, et al13 suggest that the achievement and confirmation of the elimination of locally acquired rubella circulation may require targeted immunisation of migrants from countries with low levels of rubella vaccination and the establishment of rubella genotyping in Australia.
Tetanus
| Case definition – Tetanus
Only confirmed cases are reported. Confirmed case: Requires isolation of Clostridium tetani from a wound in a compatible clinical setting and prevention of positive tetanospasm in mouse test using a specific tetanus antitoxin OR a clinically compatible illness without other apparent cause. |
In 2006, there were 3 notifications of tetanus. One case occurred in an 18-year-old (partially immunised) female from Victoria. The other 2 cases were aged 66 and 74 years.
Varicella infections
In November 2005, varicella vaccine was added to the NIP Schedule as a single dose due at 18 months (for children born on or after 1 May 2004) or at 12–13 years. In 2006, CDNA agreed to make varicella infections notifiable in Australian jurisdictions. Three categories of varicella infection are notifiable: chickenpox, shingles and varicella infection (unspecified).
By the end of 2006, 5 jurisdictions, were sending data to NNDSS. New South Wales decided in 2006 not to make varicella infections notifiable. The legal processes to make varicella notifiable in the Australian Capital Territory and Victoria were still underway.
In 2006, there were 6,156 varicella notifications from those jurisdictions, 1,514 (25%) reported as chickenpox, 1,077 (17%) as shingles and 3,565 (58%) as unspecified varicella infection.
Varicella zoster infection (chickenpox)
| Case definition – Varicella-zoster infection (chickenpox)
Both confirmed cases and probable cases are reported. Confirmed case: Isolation of varicella-zoster virus from a skin or lesion swab OR detection of varicella-zoster virus from a skin or lesion swab by nucleic acid testing from a skin or lesion swab OR detection of varicella-zoster virus antigen from a skin or lesion swab by direct fluorescent antibody from a skin or lesion swab. If the case received varicella vaccine between five and 42 days prior to the onset of rash the virus must be confirmed to be a wild type strain OR detection of varicella-zoster virus-specific IgM in an unvaccinated person AND acute onset of a diffuse maculopapular rash developing into vesicles within 24–48 hours and forming crusts (or crusting over) within 5 days. OR acute onset of a diffuse maculopapular rash developing into vesicles within 24–48 hours and forming crusts (or crusting over) AND where an epidemiological link is established when there is: contact between two people involving a plausible mode of transmission at a time when one of them is likely to be infectious AND the other has illness 10 to 21 days after contact AND at least one case in the chain of epidemiologically-linked cases is laboratory confirmed. Top of pageProbable case: Acute onset of a diffuse maculopapular rash developing into vesicles within 24–48 hours and forming crusts (or crusting over) |
In 2006, there were 1,514 notifications of chickenpox reported from 5 jurisdictions. The highest rates were reported from the Northern Territory (93.4 cases per 100,000, 193 cases) and South Australia (48.9 cases per 100,000 population, 760 cases). South Australia made varicella infections notifiable in 2002.
One thousand and sixty-four cases (70%) occurred in children aged less than 10 years. The highest rates were in the 0–4 years age group (120 cases per 100,000 population) and within this age group 3-year-olds had the highest rate (156 cases per 100,000 population, Figure 57) There were slightly more female than male cases notified (male:female ratio 0.9:1).
Figure 57. Notification rate of chickenpox, Australia,* 2006, by age group and sex
* Excluding the Australian Capital Territory, New South Wales and Victoria.
One thousand and sixty-two cases were confirmed and the remainder were probable cases.
Seventy-six were recorded as fully vaccinated for age; 7 partially vaccinated; 1,221 unvaccinated and there was no vaccination status information on the remainder of the notified cases.
Varicella zoster infection (shingles)
| Case definition – Varicella-zoster infection shingles
Both confirmed cases and probable cases are reported. Confirmed case: Isolation of varicella-zoster virus from a skin or lesion swab OR detection of varicella-zoster virus from a skin or lesion swab by nucleic acid testing from a skin or lesion swab OR detection of varicella-zoster virus antigen from a skin or lesion swab by direct fluorescent antibody from a skin or lesion swab AND a vesicular skin rash with a dermatomal distribution that may be associated with pain in skin areas supplied by sensory nerves of the dorsal root ganglia. Probable case: A vesicular skin rash with a dermatomal distribution that may be associated with pain in skin areas supplied by sensory nerves of the dorsal root ganglia. |
There were 1,077 notifications of shingles reported to NNDSS in 2006 (a rate of 5.2 cases per 100,000 population). The highest rates were in South Australia (40.2 cases per 100,000 population, 625 cases) and the Northern Territory (38.7 cases per 100,000 population, 80 cases).
There was a predominance of female cases with a male to female ratio of 0.8:1. The highest rates were in the over 85 years age groups for both males and females (54.5 cases per 100,000 population, Figure 58).
Top of pageFigure 58. Notification rate of shingles, Australia,* 2006, by age group and sex
* Excluding the Australian Capital Territory, New South Wales and Victoria.
Varicella zoster infection (unspecified)
| Case definition – Varicella-zoster infection unspecified
Only confirmed cases are reported. Confirmed case: Isolation of varicella-zoster virus from a skin or lesion swab OR detection of varicella-zoster virus from a skin or lesion swab by nucleic acid testing from a skin or lesion swab OR detection of varicella-zoster virus antigen from a skin or lesion swab by direct fluorescent antibody from a skin or lesion swab OR detection of varicella-zoster virus-specific IgM in an unvaccinated person. |
There were 3,565 cases of varicella infections (unspecified) based on laboratory diagnosis, and largely from Queensland (3,167, 89%). There was a female predominance with a male to female ratio of 0.8:1. The age distribution of unspecified varicella infections is shown in Figure 59.
Figure 59. Notification rate of varicella zoster infection (unspecified), Australia,* 2006, by age group and sex
* Excluding the Australian Capital Territory, New South Wales and Victoria.
Childhood vaccination coverage reports
Estimates of vaccination coverage both overall and for individual vaccines for children at 1 year, 2 years and 6 years of age in 2006 are shown in Tables 14, 15 and 16 respectively. During 2006, there were no significant changes in coverage for children 'fully immunised' or individual vaccines for the 1 year and 2 year milestone ages. However, there was a significant change in coverage for children 'fully immunised' and individual vaccines for the 6 year milestone age. Coverage increased by 2 to 3.5 percentage points for all vaccines between the first and second quarter of 2006 and was maintained through the following 2 quarters. A possible factor in this increase in coverage at 6 years of age is the introduction of the multivalent combination vaccine Infanrix-IPV onto the schedule that occurred in November 2005, reducing the number of vaccines to be recorded from 3 to two. Other factors that may have had an impact at the local level include promotional campaigns centred around child care or school entry or data cleaning activities. Estimates at 6 years of age for all vaccines still remain significantly lower than estimates at the 1 year and 2 years milestones.
Table 14. Percentage of Australian children born in 2005 immunised according to data available on the Australian Childhood Immunisation Register, estimate at 1 year of age
Birth date |
1 Jan–31 Mar 2005 | 1 Apr– 30 Jun 2005 | 1 Jul–30 Sep 2005 | 1 Oct–31 Dec 2005 |
|---|---|---|---|---|
Vaccine |
% immunised | % immunised | % immunised | % immunised |
| DTP | 92.2 |
91.9 |
92.0 |
91.9 |
| Polio | 92.1 |
91.8 |
92.0 |
91.8 |
| Hib | 94.2 |
94.4 |
94.8 |
94.5 |
| Hepatitis B | 94.7 |
94.4 |
94.7 |
94.4 |
| Fully immunised | 90.7 |
90.8 |
91.2 |
91.0 |
Table 15. Percentage of Australian children born in 2004 immunised according to data available on the Australian Childhood Immunisation Register, estimate at 2 years of age
Birth date |
1 Jan–31 Mar 2004 | 1 Apr–30 Jun 2004 | 1 Jul–30 Sep 2004 | 1 Oct–31 Dec 2004 |
|---|---|---|---|---|
Vaccine |
% vaccinated | % vaccinated | % vaccinated | % vaccinated |
| DTP | 95.2 |
95.1 |
95.2 |
94.8 |
| Polio | 95.2 |
95.0 |
95.1 |
94.8 |
| Hib | 93.8 |
93.7 |
93.9 |
93.6 |
| MMR | 94.0 |
93.9 |
94.0 |
93.7 |
| Hepatitis B | 95.8 |
95.8 |
95.8 |
95.6 |
| Fully immunised | 92.4 |
92.2 |
92.4 |
92.0 |
Table 16. Percentage of Australian children born in 2000 immunised according to data available on the Australian Childhood Immunisation Register, estimate at 6 years of age
Birth date |
1 Jan–31 Mar 2000 | 1 Apr–30 Jun 2000 | 1 Jul–30 Sep 2000 | 1 Oct–31 Dec 2000 |
|---|---|---|---|---|
Vaccine |
% vaccinated | % vaccinated | % vaccinated | % vaccinated |
| DTP | 85.0 |
87.0 |
88.8 |
88.8 |
| Polio | 83.8 |
87.1 |
88.8 |
88.9 |
| MMR | 85.0 |
87.1 |
88.8 |
88.9 |
| Fully immunised | 82.7 |
86.2 |
88.0 |
88.0 |
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Communicable Diseases Surveillance
This issue - Vol 32 No 2, June 2008
NNDSS Annual report 2006
Communicable Diseases Intelligence