Dengue Outbreak in a Large Military Station: Have We Learnt Any Lesson? Col Rajesh Kunwar, Col Rajat Prakash Armed Forces Medical services, India

Introduction Dengue - a mosquito borne viral infection Fast emerging in pandemic proportions Incidence increased 30-fold over the last 50 years Spread over 100 endemic countries Annually 50 -100 million cases reported 5,00,000 people require hospitalization 12,500 (about 2.5% of those affected) die.

Introduction In India from 2008 to 2013 Number of dengue cases increased by 6 – fold Deaths due to dengue by 2-fold. The outbreak of 2013 worst in last 6 years States in Southern India affected the most An outbreak reported from a large military station - more than 200 cases of dengue reported from Jun to Aug 2013

The objective To share the challenges we faced in controlling the outbreak To bring out the lessons learnt during our endeavour To suggest strategy for controlling, if not preventing, a similar outbreak in future

Methodology Study design – Descriptive The setting - The Military station located in contiguity with the civil areas on all sides Altitude of 3092 ft from mean sea level Mean atmospheric temp from 200C to 300C Relative humidity from 60% to 80%.

Methodology - The Setting The Military Station comprises of 6 Regimental Centres and many smaller units Approx strength of serving personnel & families 25,000 Medical set up Unit Regimental Medical Officers Large tertiary care hospital Station Health Organization (SHO)

Methodology - The Setting Incidence of dengue Year No. of dengue fever cases 2010 13 2011 19 2012 36 2013 > 100

The Outbreak

Methodology - Data Collection Data compiled from Existing hospital records Epidemiological case sheets Inclusion criteria All serologically confirmed cases All admitted cases Exclusion criteria Dependents treated on outpatient basis Dependents who did not report to service hospital

Control Measures Adopted Health advisories issued well in advance. Dengue Task Force (DTF) constituted at unit levels. Capsule course for training of members of DTF conducted by the local SHO. Dengue fever cases continued to be reported from almost all the units - 3 serving persons died due to severe dengue - indiscriminate fogging without much result.

The Challenges Vast training area with abundance of natural vegetation Plenty of natural and artificial breeding places Maintenance of ornamental ponds and potted plants perceived as essential Laxity in garbage clearance

The Challenges Indiscriminate and inappropriate use of hygiene and chemicals Inadequate supervision of control activity By unit/ sub-unit commanders By health functionaries Lack of awareness about dengue and its vector

The Action Senior Administrative Authorities visited the station. Working uniform changed to full sleeve dress with immediate effect. Administrative support and health resources augmented Insecticides and repellants procured

The Action Officer Commanding (OC) SHO stationed at unit which reported maximum number of cases OC SHO with a health assistant visited all units and ensured elimination of breeding places in their presence. Peri-domestic areas cleared of vegetation and all water bodies – small or large- were either drained out or larvicides were added to them.

The Action Concerted indoor and outdoor fogging in the entire station on twice weekly basis. Municipal authorities approached and daily clearance of garbage ensured Early diagnosis, adequate treatment and prompt notification of dengue fever cases ensured

The Action The epidemic curve started showing downward trend within a week The outbreak controlled in about a months time

Age-wise Distribution of Cases Age group Serving pers (%) Dependents (%) Total (%) <15 years - 23 (31.1) 23 (08.6) 16 – 20 years 36 (18.8) 12 (16.2) 48 (18.0) 21 – 25 years 60 (31.3) 07 (09.4) 67 (25.2) 26 – 30 years 19 (09.8) 03 (04.1) 22 (08.3) 31 – 35 years 27 (14.1) 04 (05.4) 31 (11.7) 36 – 40 years 24 (12.5) 28 (10.5) 41 – 45 years 20 (10.4) > 45 years 06 (03.1) 18 (24.3) 24 (09.1) Total 192 (100) 74 (100) 266 (100)

Distribution – Clinical Features

Trend of Dengue Fever Cases

Lessons Learnt - 1 Correct and timely perception of the threat is essential Need to go beyond routine Commander’s perception of threat matters Commanders to be advised well in advance about Likelihood of an outbreak Perceived severity of the outbreak Availability of resources to control Administrative and technical support required

Lessons Learnt - 2 Behavioural change of individuals is desired Protective behavior linked to risk perception Change in human behaviour brought out by Communicating risk perception to individuals Emphasising that personal protection alone not adequate in outbreak situation Health authorities imparting correct knowledge Administrative authorities having the will to implement it.

Lessons Learnt - 3 Availability of adequate health functionaries is mandatory Direct supervision by a Specialist in Community Medicine essential Availability of adequate resources Technical manpower for supervision Administrative backup for ensuring availability of health functionaries at a short notice Administrative will to support health functionaries and to implement their advice

Lessons Learnt - 4 Complete dataset helps correct perception Threat perception based on availability of data helps early onslaught Completeness of dataset can be achieved by Having a mechanism to collect, compile and analyse the data and communicate the findings Centralised registry system in the hospital Cross verification of data from clinics and laboratories Maintenance of data

Public Health Implications Future strategy for control of dengue outbreak Repeated survey for correct risk perception Assessment of behavioural change among individuals Operational research to assess the impact of ongoing public health campaign Close interaction between communities and municipal vector control services Newer research into development of vaccine for dengue

Conclusion Gaps remain in knowledge, attitude and behaviour in the community with regard to dengue prevention. Dengue surveillance and control policies Should be reviewed regularly Should focus on emergency preparedness and anticipated response planning

Conclusion Two major components of the emergency response to a dengue outbreak are: Emergency vector control to curtail transmission of the dengue virus as rapidly as possible Early diagnosis and the appropriate clinical case management of severe dengue to minimize the number of dengue-associated deaths. These responses should occur concurrently

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