Dengue Fever Management Plan For North Queensland 2005 - 2010

{6. { mosquito surveillance and control} Mosquito surveillance and control personnel have an important preventive role during nonoutbreak periods. They monitor mosquito numbers, conduct routine elimination of Ae. aegypti breeding sites and conduct training sessions for stakeholders. Mosquito surveillance and control becomes critical when an imported case or locally-acquired case of dengue is reported. Traditional dengue mosquito surveillance involves inspecting yards and premises for breeding containers in so-called “house to house inspections”. However, recently, sticky ovitraps have been developed to trap adult Ae. aegypti (Ritchie et al. 2003, 2004). Large numbers of these can be used in a surveillance network to locate hotspots of dengue mosquitoes and thus target yard inspections. Mosquito control workers become the ‘firefighters’ of dengue once an imported or locally-acquired case of dengue is notified. Dengue can rage through a suburb like a bushfire, and Ae. aegypti populations are the fuel for the fire. The more mosquitoes present, the faster the dengue spreads. Mosquito control workers conduct house-to-house inspections and eliminate mosquitoes. This is a collaborative effort between TPHUN, local government and Indigenous community councils. The methods used in mosquito elimination involve removal or treatment of containers that can harbour larvae and pupae, placement of ‘lure and kill’ ovitraps, and, where permitted, discrete interior spraying to kill adult mosquitoes. The TPHUN has recently begun trialling the ‘lure and kill’ methods to control dengue. This involves using traps baited with specific mosquito attractants to lure a mosquito to a trap where it is killed. Currently, the method is limited to ‘lure and kill’ ovitraps [originally developed by Zeichner and Perich (1999)] that are baited with a hay infusion that attracts egg-laying mosquitoes that are then killed either by a pesticide or a glue. Mosquito surveillance and control activities can, if implemented promptly, limit the extent of dengue outbreaks. After the advent of the revised DFMP in 2000, prompt notification and careful larval control and interior spraying reduced the average duration of dengue outbreaks from 29 weeks to 4.5 weeks and the total cases from 181 to 17, a 91% reduction (Ritchie et al. 2002). (See Table 3 below.) It should be noted that late notifications to TPHUN of dengue cases greatly hinder the success of control strategies. House-to-house inspections are conducted throughout the year to monitor and control mosquitoes. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 27. {6. TABLE 3. DENGUE OUTBREAKS IN NORTH QUEENSLAND BEFORE AND AFTER THE REVISED (2000) DENGUE FEVER MANAGEMENT PLAN FOR NORTH QUEENSLAND (FROM RITCHIE ET AL, 2002)* DENGUE serotype 2 2 B E F O R E AFFECTED AREA/DATE Cairns/Feb 95 Torres Strait/ Dec 96-Feb 97 Cairns/ Dec 97-Feb 98 Cairns, Port Douglas, Mossman/ Dec 97-Mar 99 Cairns/Feb 00 Townsville/ Apr-May 01 Kuranda/ Mar-Apr 02 Townsville/ Apr 02 Cairns/ May 02 DURATION (weeks)** 6 29 CASES BEFORE control measures 1 49 CASES AFTER control measures 3 159 TOTAL 4 208 No. of foci of transmission 1 6 2 11 6 6 12 3 3 70 20 478 498 15 2 2 A F T E R 6.7 3.2 17 9 33 0 50 9 1 2 2 9 18 3 21 1 3 0.4 2 0 2 1 4 3 2 0 2 1 * Reprinted with the kind permission of the Dengue Bulletin. ** Time in weeks from onset of first case until onset of last known case. Similarly, during the 1997-99 Cairns dengue outbreak, a considerable number of viraemic patients travelled to Townsville, Proserpine and Mackay, potentially introducing the virus to these communities. TPHUN and local government councils possibly curbed transmission of dengue in these locations by responding with effective mosquito control. However, late notifications of dengue activity in 2003 in both Cairns and in the Torres Strait led to explosive epidemics with hundreds of cases. Thus, the revised DFMP incorporates an emphasis on mosquito surveillance and control before dengue outbreaks occur. This way, explosive epidemics are less likely even when notification of dengue cases is delayed. 28. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 { mosquito surveillance and control} 6.1 MOSQUITO CONTROL STRATEGIES Mosquito elimination involves house-to-house inspections of high risk premises and/or dengue case contact points. Mosquito elimination is a collaborative effort between TPHUN, local government and Indigenous community councils. The methods used in mosquito elimination involve: • removal or treatment of containers that can harbour larvae and pupae (known as source reduction) • using ‘lure and kill’ strategies such as placement of lethal ovitraps • discrete interior spraying to kill adult mosquitoes (where permitted). Residual pyrethroid insecticides are used inside homes and businesses to kill adult mosquitoes. Refer to Appendix 5a for work instructions on larval surveillance, larval control, sticky ovitraps, lethal ovitraps, interior spraying and other control methods. Interior spraying was conducted preferentially over external fogging because interior spraying targets the resting sites of adult Ae. aegypti. This is truly the cockroach of mosquitoes: like a cockroach it likes to rest in dark areas of the house - under beds, in wardrobes and on dark surfaces. Spraying these areas thoroughly with residual insecticides is believed to have been crucial to the elimination of dengue in several outbreaks, since it was adopted in 1999 (Ritchie et al. 2002). Since 2003 lethal ovitraps are being trialled with promising signs of success (Ritchie, in press). 6.2 LEVELS OF DENGUE ACTIVITY 6.2.1 Ongoing prevention Mosquito control during non-outbreak situations aims to reduce Ae. aegypti populations in high risk areas. Mosquito control is very labour intensive and demands collaboration between state and local government agencies. Thus, TPHUN, local government and Indigenous community council workers attempt to eliminate Ae. aegypti breeding sites by identifying and prioritising areas likely to have containers according to (1) type of venue and (2) geographical ‘hot spots’. These targets are then surveyed, mosquitoes controlled and occupants informed about steps they can take to prevent mosquito breeding. High-risk venues: • backpackers/hostels/guest houses • hospitals • tyre dealers • schools (pre-schools, primary, high schools, TAFEs, day-care centres) • travel transit centres. Mosquitoes will breed in any container that pools water. Geographical hot spots: • older areas of town with non-screened housing (especially with a history of high Ae. aegypti numbers) • areas that have had previous dengue activity • industrial areas (especially if there are tyre yards and wreckers) • Torres Strait Island communities with high numbers of potential mosquito breeding sites. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 29. {6. 6.2.2 Sporadic cases The objective of mosquito control in response to a sporadic dengue case is to thoroughly control Ae. aegypti within 200m of ‘dengue case contact points’. ‘Dengue case contact points’ are defined as localities that were visited by the person with dengue during daylight hours, when they were vireamic, where contact with Ae. aegypti was possible (eg. residence, place of business, school). Clearly, promptness and thoroughness are essential. If the decision is made to take preventive mosquito control action, this action is taken by TPHUN, local government and Indigenous community councils. The dengue case house and case contact points are mapped and vector control activities begin immediately. The Dengue Action Response Team (DART) can be rapidly deployed to assist local government and Indigenous community councils anywhere within the TPHUN zone. Control activities include: • planning and mapping respective mosquito control response areas • conducting intensive Ae. aegypti larval control within a 200m radius of the case residence and high risk contact areas (eg. place of business, school) (see Figure 8) • controlling adult Ae. aegypti by a combination of ‘lure and kill’ trapping and interior spraying within 100m radius of the case residence and high risk contact areas (see Figure 8 and Appendix 5) • providing door-knob alerts, brochures, verbal information and handouts to the public within the treatment area. Interior spraying is generally conducted by the DART. Larval control is conducted at all premises within a 100m radius of the case by DART (see Appendix 5), and from 100 to 200m radius of the case residence and high-risk contact points by local councils, at the discretion of the medical entomologist (See Figure 8). In Queensland all mosquito control activities involving pesticide must be conducted by a licensed pest technician (see Appendix 6). Junk in yards serve as an ideal breeding ground for dengue mosquitoes. 30. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 { mosquito surveillance and control} FIGURE 8. MOSQUITO CONTROL RESPONSES FOLLOWING NOTIFICATION OF A SPORADIC CASE 200m KI 6.2.3 Outbreak response During an outbreak, most mosquito control responses occur in locations with substantial current dengue activity. Flowchart 3 illustrates the mosquito surveillance and control responses during outbreaks. Cases are mapped using GIS (see Figure 8). Mosquito control responses are planned in collaboration with local government and Indigenous community councils and depicted on the map accordingly. Areas with new dengue activity that have not been previously surveyed and treated are a priority. HI L HE RO LA U RA B L OU AR EV D RO AD EN TYRE DEALER LA NE PE NN Y ST RE ET 100m JO SE PH I NE FI O NA CL OS E WRECKERS RU TH CASE HOUSE ST ST RE ET KEY Case house Premises that fall within a 100m radius of the case house. Interior spraying, ovitrapping and source reduction is conducted. Educational material is given to occupants. Premises that fall within a 200m radius of the case house (may be extended). Source reduction is conducted and educational material is given to occupants. LA NE TPHU staff work together to inform and update the following stakeholders: • District Manager • Manager CDU Brisbane • Local GPs • Emergency Dept Doctors • Local laboratories • TPHU colleagues Public Affairs Manager facilitates media liaison and media conferences on new cases, dengue prevention and Dengue Warning and Dengue Watch Areas. Departmental briefing notes prepared * See glossary for explanation of abbreviations DENGUE FEVER management plan for North Queensland 2005 ~ 2010 AN GE LA CONFIRMED CASE of locally-acquired dengue CDC consults with the Medical Entomologist, TPHUN Director, DEHS, DART and Public Affairs Manager CDC, the Medical Entomologist and DEHS map the Dengue Warning Area and plan immediate action with local government TPHUN, local government and community councils commence Ae. aegypti control activities (larval and adult mosquito control) FLOWCHART 3. MOSQUITO CONTROL - OUTBREAK RESPONSE* 31. {6. Interior spraying is especially important during a large outbreak. Numerous viraemic people mean that there are numerous viraemic mosquitoes. The residence and adjacent premises of each dengue case (case contact points) should be sprayed to minimise the number of bloodfed Ae. aegypti that survive long enough to transmit the dengue virus. For outbreaks with numerous cases over a broad area, the entire area should be subject to larval and adult control (see Figure 9). Queensland Health has found that dengue can be eliminated from areas treated in this way within one to two months (S. Ritchie, unpublished data). FIGURE 9. MOSQUITO CONTROL RESPONSES DURING AN OUTBREAK WITH NUMEROUS CASES OVER A BROAD AREA QUOLL ST RIF LE RA NG E Native Bushland Native Bushland SCHOOL (High Risk Premise) Canefield RUPERT ST CETAC RIVE EAN D RD WHALE RD SEAGRASS ST LEWIS LANE DUGONG WA Y ALEX ST BACKPACKERS (High Risk Premise) Canefield L BU LD ER RD Native Bushland HOSPITAL (High Risk Premise) CAROLINE DR IVE OZ KEY Confirmed cases MALCOLM ST Canefield Both larval and adult mosquito control is conducted. Note: Mosquito control is not conducted on non-urban sites such as canefields. 32. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 { mosquito surveillance and control} 6.2.3.1 Staff issues during outbreaks During an outbreak, many staff will be involved in extensive field work and other related duties. Preparations should be made to ‘back-fill’ these staff with personnel who will be able to manage ongoing prevention work, as well as to provide occasional relief to the field officers to avoid staff ‘burn-out’. These preparations should be planned before an outbreak occurs so that a pool of relief workers can be identified. Workplace Health and Safety obligations require organisations to protect the health and safety of their employees. It is important for employers to ensure that the following resources are made available to employees conducting mosquito surveillance and control operations in the field: • insect repellent • sunscreen (15+ minimum) • hats • rehydration fluids including water. Employees should have a two hour midday break particularly during hot weather and/or over prolonged outbreaks. They should also have access to dog behaviour awareness training, if possible. For security reasons, it is prudent that field officers do not operate in isolation but travel in teams of at least two. 6.3 STAKEHOLDER PLANNING Stakeholders’ plans for dengue control should include identifying the organisation’s • labour and non-labour resource capacity • equipment and insecticides to be used • training needs before an outbreak occurs. Training should be conducted in: • the relevant legislation, including powers of entry, trespassing and evidence gathering (see Appendix 6) • mosquito control roles and responsibilities according to this Dengue Fever Management Plan. All training should be revised if an outbreak occurs. Stakeholders also need to ensure that all personnel intending to carry out pest management activities receive the relevant mandatory training qualification [Certificate II in Asset Maintenance (Pest Management – Technical)]. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 33. {7. 34. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 { public education} Mosquito control workers cannot eliminate mosquito breeding in all homes and businesses in North Queensland, so an important element of dengue management is the education of members of the public about their role in eliminating mosquito breeding at home and protecting themselves from dengue. Education programs utilise public relations, advertising, promotional materials (brochures, posters), training sessions, a web site (www.health.qld.gov.au/dengue) and information sheets. Programs are either targeted at the general community or specific community settings such as schools, work sites and travellers’ hostels. FIGURE 10. The Dengue Blitz 04 media campaign was an effective tool to keep the public informed during the multiple outbreaks of 2004. 7.1 ONGOING PUBLIC EDUCATION Preventive public awareness during non-outbreak periods involves informing the general public about the risk of outbreaks and the importance of regular mosquito control. These population level education strategies about dengue prevention are designed to create and maintain awareness and motivation within the community. These activities are best timed to occur just before and throughout the North Queensland wet season (December-April). Activities include: • media liaison and media releases (see Appendix 7) • media conferences featuring media-trained, authoritative spokespeople • advertising (TV, radio and print) • publicity for opportunistic promotional strategies (eg. Flozzie the Mozzie). Key preventive messages include: • facts about the disease • urging householders to adopt dengue-protective behaviour (tip out or dispose of unwanted containers, use personal and household insect repellent, screen houses). FIGURE 12. Dengue Fever poster FIGURE 11. Media coverage of dengue. Articles in the media educate the public about how they can prevent dengue. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 35. {7. 7.2 SPORADIC CASES Education in response to sporadic cases is specifically targeted at occupants of premises in the immediate vicinity of the imported or possible dengue case. The objective is to heighten awareness of the risk of local transmission of dengue fever in the immediate vicinity of the dengue case and urge occupants to take immediate steps to control Ae. aegypti. If the possible locally-acquired case becomes confirmed, the Outbreak Response Procedures would be followed. One confirmed locally-acquired case is defined as an outbreak. In general, the media is rarely informed of sporadic imported cases. If the media does become aware of the sporadic case, TPHUN will prepare a response reassuring the public of the preventive steps being taken by TPHUN, local government and community councils. 7.3 OUTBREAK RESPONSE During outbreaks, educational programs are intensified. TPHUN staff, coordinated by the Public Affairs Manager, keep the public informed of outbreak details. Educational strategies aim to heighten public perception of immediate risk and motivate the public to take action. Key outbreak response messages include: • Dengue Warning Area - this classification is used for suburbs where local transmission has occurred recently (in the past four weeks) and is delineated by specific geographical boundaries • Dengue Watch Area - this classification is used for all suburbs or towns that are at risk of local transmission during outbreak periods. (For a few cases of local transmission, the Dengue Watch Area may be neighbouring suburbs. For a serious outbreak, the Dengue Watch Area may cover the whole North Queensland zone.) • map of Dengue Warning Areas • tally on number of cases • preventive and protective measures • results of mosquito surveys • signs and symptoms • importance of seeking medical advice, for those with symptoms of dengue. Outbreak response publicity involves informing the public of potential dengue outbreaks and providing updates on current outbreaks. Activities include: • media liaison and media releases • advertising • customised media plan for probable cases • media conferences featuring trained, authoritative spokespeople • asking media spokespeople from Divisions of General Practice and local councils to reinforce messages • keeping dengue website updated • keeping relevant agencies (eg. tourism bodies) informed of public relations activities to promote collaboration and minimise the risk of negative reactions to media and other dengue control strategies • preparing departmental briefings. 36. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 { education} 7.4 PROFESSIONAL EDUCATION AND STAFF TRAINING TPHUN environmental health staff and DART conduct educational training sessions, as required, with local government and Indigenous community council staff in all communities considered at risk of dengue fever outbreaks. Topics covered include: • overview of dengue fever • importance of being pro-active • larval control procedures • adult Ae. aegypti control procedures • legislative requirements. During an outbreak, TPHUN CDC staff will arrange in-service training in places that are not serviced by a major referral hospital. This training is arranged in collaboration with the hospital infectious disease physician for health professionals and laboratories. Topics include clinical management and public health management of dengue fever. Similarly, early in an outbreak, community health staff also need in-service training about the clinical and public health aspects of dengue. The North Queensland Workforce Unit has resources about dengue designed specifically for community health staff, including rural and remote Registered Nurses and Indigenous Health Workers. 7.5 STRATEGIC ONE-TO-ONE EDUCATION TPHUN, local government and Indigenous community councils conduct strategic one-to-one education sessions to personnel in high-risk premises or geographical settings (such as schools). In addition, occupants of premises in the vicinity of the imported or possible locally-acquired case are informed of the potential risks. Topics covered include the signs and symptoms of dengue, dengue natural history and how people can prevent mosquito breeding in their home and workplace. Dengue brochures and posters are handed out if appropriate. For some businesses (eg. hospitals, schools) customised dengue mosquito control programs are developed. 7.6 OPPORTUNISTIC COMMUNITY EDUCATION TPHUN staff conduct community education sessions with service clubs and other community groups and organisations (eg. Neighbourhood Watch, P&Cs, schools) when time allows and as requested. In addition, occupants of premises in the vicinity of the imported or possible locally-acquired case are informed of the potential risks. 7.7 HEALTH PROMOTION RESEARCH Dengue knowledge and awareness research over the past decade has measured: • public perception of the immediate risk • the public’s ability to recall the two key messages, which are: - eliminate mosquito breeding sites - use insect repellent Health promotion and public affairs staff periodically research the public’s existing knowledge, attitudes and behavioural practices with respect to dengue fever prevention and control. Responses to existing resources are also researched and resource materials reviewed accordingly. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 37. {8. 38. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 { managing multiple outbreaks} For the purposes of this plan, multiple outbreaks can be defined as substantial outbreaks which occur simultaneously in two or more separate locations. INTERNAL AND STAKEHOLDER COMMUNICATIONS During multiple outbreaks, such as those in Cairns, the Torres Strait and Townsville during 2004, TPHUN staff from communicable disease control (CDC), medical entomology, and public affairs meet frequently for updates on the status of the outbreaks and to prioritise activities. Status reports and actions are summarised using a risk analysis table (see Appendix 8). TPHUN alert and update other stakeholders during all outbreaks (GPs, hospitals, mosquito control officers, councils, and public and private laboratories). These updates are particularly important when multiple outbreaks are occurring, as high levels of dengue activity increase the risk of outbreaks expanding or being transported to other high-risk areas. TPHUN enhance their public education strategies during multiple outbreaks to maximise opportunities to communicate dengue prevention messages to the general public, media and stakeholders. MOSQUITO SURVEILLANCE AND CONTROL During multiple outbreaks mosquito control responses must be carefully prioritised at the discretion of the TPHUN medical entomologists in consultation with CDC. Priority may be given to locations where: • there is a high risk that the outbreak could become substantial • substantial dengue activity has occurred previously (particularly where the prior dengue activity was a different strain to the current strain) • there is known to be intense mosquito breeding (eg. older, unscreened open houses such as Queenslanders) • the outbreak could spread rapidly to other areas (eg. an outbreak in Torres Strait Islands spreading to Cairns or Townsville or an outbreak in industrial areas spreading to urban areas) • there are suspected dengue cases, but confirmed dengue cases have not recently been reported in the area. The level of mosquito control responses and entomological interventions required will be determined according to the level of priority and staffing levels (see below). It may be necessary to abbreviate the standard 100m response area (see page 31), and to rapidly control mosquitoes using a mass deployment of ‘lure and kill’ traps and limiting internal spraying to the case premises and adjacent premises. BACKFILLING AND USE OF EMERGENCY STAFF It is often necessary to second additional staff from other Public Health Units or from elsewhere in Queensland Health during multiple or prolonged outbreaks. Staff seconded for large scale response activities may include DART members, EHOs, nurses, local government staff and vector control officers. The Data Officer, CDC, TPHUN, is responsible for data entry from large and multiple outbreaks. During these periods it may be necessary to negotiate the Data Officer’s availability with the Medical Officer, CDC. When staff are seconded from elsewhere in Queensland Health, it may be necessary to negotiate terms with the relevant district management. Outbreaks can escalate very quickly, so ideally a pool of relief staff should be identified during non-outbreak periods. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 39. {9. 40. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 {after the outbreak} AFTER THE OUTBREAK An outbreak will be declared over after an interval of three months has passed since the onset of the last case. It is pragmatic to wait three months to be certain that transmission of dengue has ceased as there may be some undetected transmission following the last recognised case. The Public Affairs Manager will then notify the public that the outbreak is over. After an outbreak, TPHUN may convene a debriefing and review of the outbreak with the relevant local government and Indigenous council personnel as soon as is practical. Each outbreak should be reviewed at the annual DFMP Executive Committee meeting. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 41. { references} Gubler DJ (1997). Dengue and dengue haemorrhagic fever: its history and resurgence as a global public health problem. In: Dengue and Dengue Hemorrhagic Fever. DJ Gubler and GK Kuno eds, CAB International 1997. Hanna JN, Ritchie SA, Merritt AD, van den Hurk AF, Phillips DA, Serafin IL, Norton RE, McBride WJH, Gleeson FV and Poidinger M (1998). Two contiguous outbreaks of dengue type 2 in north Queensland. Med J Aust 168: 221-225. Hanna JN, Ritchie SA, Phillips DA, Serafin IL, Hills SL, van den Hurk AF, Pyke AT, McBride WJH, Amadio MG and Spark RL (2001). An epidemic of dengue 3 in far north Queensland, 1997-1999. Med J Aust 174:178-182. Hare FE (1898). The 1897 epidemic of dengue in north Queensland. The Australasian Medical Gazette. 17: 98-107. Montgomery BL and Ritchie SA (2002). Roof gutters: a key container for Aedes aegypti and Ochlerotatus notoscriptus (Diptera: Culicidae) in Australia. Am J Trop Med Hyg 67: 244-246. Ritchie SA, Hanna JN, Hills SA, Piispanen JP, McBride WJH, Pyke A, and Spark RL (2002). Dengue control in north Queensland, Australia: case recognition and selective indoor residual spraying. Dengue Bull 26: 7-13. Ritchie SA, Long SA, Hart AJ, Webb CE, and Russell RC (2003). An adulticidal sticky ovitrap for sampling container-breeding mosquitoes. J Am Mosq Control Assoc 19:235-242. Ritchie SA, Long S, Smith G, Pyke A, and Knox TB (2004). Entomological investigations in a focus of dengue transmission in Cairns, Queensland, Australia using the sticky ovitrap. J Med Entomol 41: 1-4. Ritchie SA (In press). Evolution of dengue control strategies in north Queensland, Australia. Arborvirus Research in Australia 9. Zeichner BC and Perich MJ (1999). Laboratory testing of a lethal ovitrap for Aedes aegypti. Med Vet Entomol 13: 234-238. 42. DENGUE FEVER management plan for North Queensland 2005 ~ 2010 { glossary} Aedes aegypti The mosquito vector for dengue in North Queensland Geographic Computerised information system Information used to process, map and output System (GIS) geographic data HAI Haemagglutination Inhibition Assay: a confirmatory test for dengue Two different classes of antibodies: IgM indicates a recent or acute infection whereas IgG indicates a prior infection Periods between epidemics Antigen A substance which can induce a specific immune response and react with the products of that response AQIS Australian Quarantine and Inspection Service Assay A laboratory test that not only is able to detect something (eg. an antibody) but also is able to measure the amount (eg. of the antibody) present CDC DEHS Communicable Disease Control, TPHUN Director of Environmental Health Services, TPHUN IgM and IgG Inter-epidemic Japanese Infection caused by a virus encephalitis (JE) transmitted by mosquitoes Northern Zone The North Queensland zone covered by TPHUN Outbreak A localised, as opposed to generalised, epidemic (NB: One case of locally-acquired dengue in North Queensland is enough to declare an outbreak) Polymerase chain reaction (a technique used to amplify specific sequences of genetic material so that they may be more easily identified. May be applied to the detection of dengue virus) Royal Australian Air Force Non-outbreak situations A strain of a microorganism that has been distinguished from other strains by a serological (ie. immunological) test Tropical Public Health Unit Network Vector Control Officer A living carrier that transports an infectious agent from an infected individual (or its wastes) to a susceptible individual (or its food or immediate surroundings) Dengue Action TPHUN team focusing on dengue Response Team control (DART) Dengue Fever Infection caused by one of four serotypes of dengue viruses that has been transmitted by Ae. aegypti PCR Dengue Potentially fatal complication of Haemorrhagic dengue fever, characterised by Fever (DHF) severe bleeding Dengue Shock Potentially fatal complication of Syndrome (DSS) dengue fever, characterised by shock Dengue Warning Suburb or town that has had Area confirmed local transmission of dengue during an outbreak, delineated by specific geographical boundaries Dengue Watch Suburbs, towns or cities that are Area at risk of local transmission of dengue during an outbreak EHO EHW EIA Environmental Health Officer Environmental Health Worker Enzyme immunoassay: used to test biological samples (eg. blood) for the presence of antibodies The constant presence of a disease or infectious agent within a given geographic area or population group The occurrence in a community or region of cases of an illness or other health-related events clearly in excess of what is expected RAAF Routine Serotype TPHUN VCO Vector Endemic Viral culture The isolation of a virus by propagating it in a special culture medium Viraemia The presence of viruses in the blood Epidemic DENGUE FEVER management plan for North Queensland 2005 ~ 2010 43.