Delivering a Healthy WA
Disease WAtch

July 2014, Volume 18, issue 2

Full issue

Middle East respiratory syndrome coronavirus (MERS-CoV) infection made notifiable

MERS-CoV became a notifiable infectious disease in Western Australia, as of Wednesday 2 July, following publication of a notice in the Government Gazette the previous day.

An accompanying notice designated MERS-CoV a “dangerous infectious disease”, as defined in the Health Act 1911. The latter designation allows the use of formal powers – as outlined in section 251 of the Act – to order public health disease control measures such as isolation, quarantine, and testing, should they be necessary.

Attending doctors and pathology laboratories are now required by law to notify the WA Department of Health of persons considered on clinical and epidemiological grounds, or as a result of testing, to have MERS-CoV infection.

Background

MERS-CoV belongs to the same family of viruses as the Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) that emerged in southern China in late 2002 and subsequently caused outbreaks of serious respiratory disease in several countries, along with considerable community anxiety and disruption to affected economies and international travel. MERS-CoV does not appear to be as easily transmitted from person-to-person as was SARS-CoV, but understanding of the source of MERS-CoV and its transmissibility remains limited.

MERS-CoV has been recognised as causing severe respiratory and associated systemic disease in humans in countries of the Arabian Peninsula and surrounding area since April 2012, with the highest incidence in Saudi Arabia and the United Arab Emirates (UAE). It has a mortality rate of around 35% in diagnosed cases, with middle-aged and elderly people with an underlying disease being particularly susceptible. The disease has shown a propensity for transmission within households and in healthcare facilities to other patients and healthcare workers.

The rate of transmission of MERS-CoV increased significantly in April and May, especially in Saudi Arabia, but has declined since. To date, affected countries in the Middle East have included Saudi Arabia, the UAE, Jordan, Qatar, Iran, Kuwait, Oman, Lebanon and Yemen. Other countries reporting cases in travellers from the Middle East region have included Algeria, Egypt, Tunisia, France, Germany, Greece, Italy, the Netherlands, the United Kingdom, Malaysia, the Philippines and the USA.

No cases of MERS-CoV have been diagnosed in Australia to date, although many travellers from the Middle East region with respiratory diseases have been investigated. It seems inevitable that cases will eventually be confirmed in Australia, given the frequency of travel from the Middle East region, including pilgrims returning from the Hajj and Umrah.

Case definition

Doctors are advised to consider testing for and notification of MERS-CoV in persons who meet the following criteria for a suspect case:

Suspect case (patient under investigation)

A person with an acute respiratory infection, which may include history of fever or measured fever (≥ 38°C) and cough, AND

  • evidence of pulmonary parenchymal disease (e.g. pneumonia or Acute Respiratory Distress Syndrome (ARDS)), based on clinical or radiological evidence of consolidation, AND
  • residence in or history of travel to Middle Eastern countries where MERS-CoV is believed to be circulating, in the 14 days before onset of illness (OR close contact with a symptomatic PROBABLE or CONFIRMED case within 14 days before onset of illness), AND
  • not already explained by any other infection or aetiology, including all clinically indicated tests for community-acquired pneumonia according to local management guidelines. It is not necessary to wait for all test results for other pathogens before testing for MERS-CoV.

Probable and confirmed cases are currently defined as follows:

Probable case

A person fitting the definition of a “suspect case” but with absent (e.g. patient has died or no specimens remain) or inconclusive (e.g. negative on a single inadequate specimen, or positive on a single PCR target) testing for MERS-CoV, AND

  • close contact with a symptomatic laboratory-confirmed case.

Confirmed case

A person with laboratory confirmation of infection with MERS-CoV. PCR testing for MERS-CoV is available at PathWest.

Notification  

Please contact the on-call Public Health Physician at the Communicable Disease Control Directorate (CDCD) urgently to notify any suspect, probable or confirmed cases (telephone 9388 4801 during office hours, or 9328 0553 after hours).

For more information visit:

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Campaign bid to boost varicella vaccination rates

Varicella (chickenpox) is a common, highly contagious disease caused by varicella-zoster virus. Varicella infection causes a generalised itchy rash and blisters. It typically starts on the trunk and face and spreads to the limbs.

Most children who get varicella have a mild illness but some can become quite ill. Infection is, on average, more severe in adults and can cause serious and occasional fatal illnesses in people with low immunity (including pregnant women).

Under the national immunisation program (NIP), the varicella vaccine is provided free to all children aged 18 months of age. This vaccine is now included in the measles, mumps and rubella vaccine as a combination vaccine – MMRV. The varicella vaccine is also offered through the year 8 school-based immunisation program.

In Western Australia, uptake of the varicella vaccine is lower than for other vaccines. From July 2014 it was added to the list of vaccines required for a child to be considered ‘fully vaccinated’ on the Australian Childhood Immunisation Register (ACIR). This change is likely to lower the state’s immunisation rates to below the nationally accepted target of 90%.

The low vaccine uptake and potential severity of disease, particularly in adults, has led to a decision by WA Health to launch a chickenpox campaign in August 2014.

WA Health recently conducted a survey to determine parents’ level of knowledge and attitudes to chickenpox. The survey found that parents’ main reasons for not accessing the varicella vaccine were that they did not consider it as effective as natural immunity and did not see chickenpox as a serious disease. The results highlighted a need to raise awareness of the potential severity of varicella and the importance of vaccination. The campaign will thus be aimed primarily at parents of pre-school children.

The community component of the campaign will consist of radio messages, targeted website advertising and some print advertising in community newspapers.

Posters and brochures will also be sent to general practices, local councils, hospitals, childcare centres, Medicare Locals and Centrelink offices to raise awareness among immunisation providers.

The campaign is scheduled to run from mid-July to the end of August 2014.

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Trends in notifications of HIV infection in WA

In 2013, 119 new cases of HIV infection were notified in Western Australia, similar to the record number of 121 cases reported in 2012. HIV notifications in WA have increased steadily over the past decade to more than double the number of cases reported in 2004 (n=51). While HIV notifications have increased, notifications of AIDS and deaths in persons with HIV infection have remained relatively stable over this period (Figure 1).

In 2013, 94 males and 25 females were notified with HIV infection (male to female ratio 3.8:1). The median age of all HIV cases notified in 2013 was 37 years (range: 18 to 77 years) with the median age in males 6 years older than that in females (39 vs. 33 years).

Figure 1 -Number of notifications for HIV infection, AIDS and deaths in persons infected with HIV, WA, 1983 to 2013
Figure 1 – Number of notifications for HIV infection, AIDS and deaths in persons infected with HIV, WA, 1983 to 2013

Risk exposures

The rise in newly notified HIV infections in WA can be attributed to increases in notifications among both men who have sex with men (MSM) and people acquiring the virus through heterosexual exposures.

From 2004 to 2013, HIV notifications among MSM almost doubled from 31 to 58 new cases, with most of this increase occurring after 2009. In 2013, the majority of these men had acquired their infection in Australia (69%; n=40). There was a more dramatic almost 4-fold increase in the number of heterosexually acquired HIV notifications between 2004 and 2010 (17 to 66 cases), with a relative stabilisation since then (Figure 2). In 2013, most heterosexually acquired cases were infected overseas (83%; n=45), and the majority were male (61%; n=33).

Heterosexual acquisition was the most commonly reported risk exposure for HIV infection in WA between 2005 and 2012, accounting for more than half of all new cases over this period (54%; n=388). However, the disparity with MSM has decreased progressively since 2010, with MSM again becoming the most commonly reported risk exposure in 2013 (49%; n=58) (Figure 2).

Figure 2 - HIV notifications by exposure  category, WA residents, 2004 to 2013
Figure 2 – HIV notifications by exposure category, WA residents, 2004 to 2013

Trends by place of acquisition and birth among heterosexual cases

Most of the recent increase in heterosexually acquired cases was among overseas-born people who also acquired HIV infection overseas. Between 2004 and 2013, the number of cases reporting heterosexual exposure who were born and acquired their infections overseas increased from 7 to 34 cases, although the number has been relatively stable since 2009 (Figure 3). In 2013 the majority of these cases were sub-Saharan African born males (29%; n=10) and females born in sub-Saharan Africa (18%; n=6) or South-East Asia (18%; n=6). The majority of overseas born and acquired heterosexual cases from 2013 acquired HIV infection in their region of birth (79%; n=27).

Since 2010, notifications in Australian-born people who acquired HIV overseas, particularly in South-East Asia, have been relatively stable, comprising 20% of heterosexual cases in 2013 (Figure 3). The number of Australian-born, Australian-acquired heterosexual cases has remained relatively steady over the past 10 years, ranging between 4 and 11 cases per year.

Figure 3 - HIV notifications with a reported heterosexual exposure by place born and acquired, WA residents, 2004 to 2013
Figure 3 – HIV notifications with a reported heterosexual exposure by place born and acquired, WA residents, 2004 to 2013

HIV infection in Aboriginal people

The number of HIV notifications in Aboriginal people has remained low and relatively stable in recent years, and no new cases were notified among Aboriginal people in either 2012 or 2013 (Table 1). The age-standardised HIV notification rate has remained similar to, or lower than, the rate in non-Aboriginal people over this period.

Year Aboriginality Total Rate ratio (Aboriginal: Non-Aboriginal)
Aboriginal Non-Aboriginal
Number Per cent ASR Number Per cent ASR Number ASR
2009 3 3.3 5.3 87 96.7 4.1 90 4.1 1.3
2010 2 1.8 3.1 111 98.2 5.0 113 5.0 0.6
2011 5 4.8 6.0 100 95.2 4.4 105 4.4 1.4
2012 0 0.0 0.0 121 100.0 5.1 121 5.0 0.0
2013 0 0.0 0.0 119 100.0 4.9 119 4.8 0.0

Notes: ASR = Age-standardised notification rate per 100,000 population

Table 1 – Number and age-standardised rate of HIV notifications in WA by Aboriginality, 2009-2013

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Hot HIV topics in 2014

7th National HIV Strategy

Five new national strategies addressing HIV, hepatitis B, hepatitis C, sexually transmissible infections (STIs) and Aboriginal and Torres Strait Islander blood-borne viruses (BBVs) and STIs have been released to provide the policy framework for Commonwealth, State and Territory governments and key stakeholders to respond to BBVs and STIs until 2017.

The 7th National HIV Strategy includes several targets that are driven by the Australian Government being a signatory to the 2011 United Nations Political Declaration on HIV/AIDS.

Rapid HIV (point-of-care) testing

A wide range of point of care (PoC) tests is in use in both developed and developing countries. In December 2012, the TGA approved the first PoC test (Alere Determine™ HIV Combo) for use in Australia as a preliminary screening test. On 1 May 2014, the WA AIDS Council’s M Clinic became part of the Kirby Institute’s national trial of PoC testing in clinical settings. For more information visit the M Clinic website (external site).

Amendment to the Pharmaceutical Benefits Scheme 

The Pharmaceutical Benefits Scheme (PBS) has been amended to broaden the group of HIV-positive people eligible for subsidised treatment. The April 2014 amendment allows doctors to prescribe HIV treatment for people with a CD4 cell count of above 500 cells/mm3 with no clinical symptoms. Previously patients with no clinical symptoms had to have a CD4 cell count of below 500 cells/mm3 to qualify for the subsidy.

The CD4 cell count of an HIV-negative adult is usually between 600 and 1200 CD4 cells/mm3. As a result of the amendment, anyone with HIV and a Medicare card can receive subsidised treatment through the PBS. This enables people diagnosed with HIV to start treatment earlier.

Treatment can reduce HIV to undetectable viral plasma levels. This means that an HIV-positive person is far less likely to pass on HIV to a sexual partner. Current findings show that the risk of HIV transmission is extremely low from a HIV-positive person with an undetectable viral plasma level. This may motivate people to start treatment earlier.  Many experts say that untreated HIV causes damage from the time of infection.

Viral load suppression, practising safe sex and adopting safe injecting practices can all reduce the risk of HIV transmission.

Guidelines for post-exposure prophylaxis

Post-exposure prophylaxis (PEP) is a course of antiretroviral drugs used to reduce the risk of HIV infection after potential exposure has occurred.

The national PEP guidelines (external site) were released in 2013.

WA Health’s operational directive on PEP following a non-occupational exposure is currently being updated in consultation with key stakeholders.

Pre-exposure prophylaxis

Pre-exposure prophylaxis (PrEP) refers to antiretroviral drugs used to reduce the risk of HIV infection before a potential exposure. PrEP is available in a number of countries. The Centers for Disease Control and Prevention (CDC) in the United States recently released guidelines supporting the prescribing of PrEP for high-risk individuals.

PrEP is not generally available in Australia although several demonstration projects and trials are underway in the Eastern States. The aim of these trials is to provide information about the effectiveness of PrEP in Australia and to help develop policies around PrEP that are appropriate for Australia.

Over the next few months, WA Health will develop a position paper on PrEP in consultation with key stakeholders.

20th International AIDS Conference (AIDS 2014)

AIDS 2014 (external site) was held in Melbourne from 20 - 25 July 2014.

WA stakeholders hosted a booth in the AIDS 2014 Global Village. The Global Village was an interactive and participatory space consisting of art exhibitions, installations, film screenings, performances, workshops, networking areas and marketplace booths. It was open to both conference delegates and non-delegates including community organisations from around the world, local and national groups and the general public.

The WA booth entitled “Size doesn’t matter in Western Australia” celebrated the uniqueness of WA within the Asia Pacific region. Visitors learnt about WA's partnership approach to HIV prevention and management and its relevance to other remote areas within the Asia Pacific region.

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Decline in HPV vaccination across three scheduled doses: A tale of two sexes

As part of Western Australia's school-based vaccination program, males and females in year 8 are offered 3 doses of the human papillomavirus (HPV) vaccine to protect them against a number of cancers, including cervical and throat cancers, as well as genital warts. Girls have been offered this vaccine at school since 2009, with boys joining the program in 2013.

It is important that children receive all three doses to gain full and effective protection. Recent data extracted by the WA Department of Health show a decline in uptake over the course of the 3-dose schedule, particularly in boys. Data analysed from 2012 and 2013 showed that only 86% of males were recorded as having received dose 3 compared with 98% receiving dose 1 (a 12% decline), and only 92% of females having received dose 3 compared to 99% receiving dose 1 (a 7% decline) (Figure 1).

Figure 1 - Proportion of children who returned consent for HPV to receive doses 1-3, females (2012) and males (2013)
Figure 1 – Proportion of children who returned consent for HPV to receive doses 1 – 3, females (2012) and males (2013)

Absence from school (largely due to illness) has been reported as a major reason for non-completion of the 3-dose schedule in a study of Australian females1. Although the reasons for these differences in decline between sexes have not been fully investigated, females have had an additional year to receive any previously missed doses. Figures for males may therefore improve over the course of 2014, however the proportion of all children who have returned consent forms but not completed the full schedule is still of concern.

These data highlight the importance of ‘catch ups’ for children who do not complete the full HPV schedule at school. A child who has not received a scheduled dose is eligible to receive a free catch-up vaccination at their school, community health or local government vaccination clinic or from their general practitioner. The details of this vaccination should be forwarded to the Department of Health to ensure the child’s vaccination record is up to date and prevent over-vaccination.

To raise HPV vaccination rates:

  • parents and providers should familiarise themselves with the school-based vaccination program schedule
  • all eligible (year 8) children should be encouraged to have their HPV vaccines at school
  • catch-up vaccinations should be offered to children who did not complete their HPV vaccine course either in the current school year, or when they are in year 9.

References

1. Watson M, Lynch J, D'Onise K, Brotherton J. Barriers to better three-dose coverage with HPV vaccination in school-based programs. Australian and New Zealand Journal of Public Health. 2014;38(1):91-2.

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