Spatial Pattern Analysis - Dengue Fever
![Picture](/uploads/5/0/2/9/50290067/denguefever-studyarea_1.jpg?501)
Dengue Fever is a disease that is painful and potentially fatal that is spread by mosquitoes. With an estimate of as many as 100 million people contracting this disease each year it is imperative to better understand the disease in order to identify strategies that might reduce the disease. This analysis looks at an outbreak of the disease over a 6 week period in a small village in southeast Asia.
To begin, an analysis was undertaken to look at the disease and its spatial patterns. Using a variety of statistical methods it was found that:
These values were used in the hot spot analysis with a distance band = 75m. These results are shown below:
To begin, an analysis was undertaken to look at the disease and its spatial patterns. Using a variety of statistical methods it was found that:
- the incidents were clustered around the study area (z-score=-26.91), proving that there is statistical evidence that the disease does spread based on spatial distribution.
- the mean distance from neighbour to neighbour was 9.8m, the maximum distance to a neighbour was 52.7m.
- at 75m the probability is greatest to be a spatial cluster.
These values were used in the hot spot analysis with a distance band = 75m. These results are shown below:
- the north-east to centre of the village tended to be a hot spot for outbreaks of the fever (witnessed a majority of the outbreaks), while the northwest was a cold spot (did not have a significant outbreak).
- the centre of the village was the mean centre to outbreaks for all 6 weeks during the study.
To understand why the centre of the study area was such a hot spot, a look into some underlying variables were undertaken. During the 6 week study 294 incidents occurred. Of these 294 incidents, 56% to the female population while a slightly lower percentage attacking the male population at 44%. It was also found that there were more cases found for those between the age of 14-42 with an average age of 30. The age did not have a very significant affect on the distribution of incidents. The mean male age of contracting the fever is below average at 28 years of age while female has an average of 32 years of age.
As the weeks of the study went on, the number of incidents increased dramatically, and then fell back down in the final week. The most noticeable effect was on the populations under the age of 20 resulting in a large amount of incidents, especially week 5 where 50 incidents were recorded for the ages 20 and under. There was also a similar trend for those under 30, 40 and 60 as they each increased and then dramatically decreased during week 6.