ISSS608 2017-18 T1 Assign DENG CHUNLING

Disease Outbreak Investigation

Objective & Methodology

In light of the serious situation that Smartpolis faces (several deaths reported!), I need to:

1. Source: Determine origin of disease outbreak

2. Spread: Find out medium of transmission

3. Control: Suggest measures to contain spread

My approach to this problem is:

Action Step	Result
Filter blog text for spots of flu	Exclude non-disease blogs from analysis
Determine type of symptoms	Categorise symptoms into water, air or human
Correlate spots with map and time	Animate disease outbreak path by timelapse
Drill down into water-borne	Study the origin, spread and contributing factor
Drill down into air-borne	Study the origin, spread and contributing factor
Drill down into human-transmitted	Study the origin, spread and contributing factor

So that I can suggest containment measures and geo-fencing for each of the transmission type.

Data Preparation

Efforts are needed to transform the "Microblog" dataset into a format that is conducive for visualization.

Variable	Treatment	Description	Screenshot
Location	Break into "Lat" and "Lon" respectively	SAS EG workflow to prepare Lat/Lon and save to library
Text	Find stemmed words from text	SAS EM workflow to extract stemmed words from library. This will help avoid fuzzy lookup e.g. I search for "ache" but "mustache" is returned
Text	Filter microblogs to only pre-defined symptoms	SAS EG workflow to join documents and words list. Note that these are all stemmed words so whatever forms of words are in the microblogs, even misspelled ones, will be detected.
Symptom	Group symptoms into 3 broad categories: related to digestive system, respiratory system or muscle. The rationale is that some people may know that they have flu, but others are just describing the symptoms.		ddd

Origin and Initial Spread

My Tableau visualization below allows me to look at the disease situation in a multi-dimensional view.

• 

  Overall Disease Investigation

• 

  Daily Disease Dashboard

We can see from the Overall Dashboard, by filtering the date value one by one, that the flu outbreak happens on 18 May 2011. This is confirmed by another dashboard which shows the day-by-day view by more clearly. 18 May is also the day where we see a lot of symptoms coming out, from a mere hundred to a few thousand microblogs.

17 May	18 May

Comparing these two days, we know two things. First, the source of this flu originated from the downtown area, and initially it spread to the east. We see that this initial spread is along one of the water pipe, whereas the wind direction on 18 May is to the west. This is the indication that the initial spread is due to water-borne factors, not air-borne, because the wind direction is opposite the spread direction.

Transmission and Containment

Following the initial spread on 18 May, we see another outbreak on 19 May, but this time with very interesting characteristic.

18 May	19 May

We see that the complaints of nausea and diarrhea increases very rapidly, especially along the river in Westside, Plainsville and Smogtown. The wind direction on 19 May is North West, so we are very confident that this second surge in disease outbreak is due to water-borne factor again - not along the water supply, but rather the river itself.

Containment Suggestions

Next let's look at the time trend.

Link to Tableau Page

Feel free to access and comment on my visualization project here:

https://public.tableau.com/profile/deng.chunling#!/vizhome/cldeng_2016/DiseaseControl?publish=yes