The dengue virus is being spread by Aedes mosquitoes. Mosquitoes like Anopheles, Culex and other species do not carry the dengue virus. Does that mean Aedes mosquitoes suddenly began to breed over the last 2-3 months? Not really.
There were Aedes mosquitoes in Dhaka before dengue broke out. The virus probably was brought in by a dengue-infected mosquito or man who may have flown in to Dhaka by plane. The Aedes mosquitoes which were here before, didn’t carry the dengue virus. They would bite people, but not infect them.
When a female Aedes mosquito bites a dengue patient, it is infected by the virus. Then when it bites another person, it infects that person with the dengue virus. That is how the disease is spread. So if the dengue patients can be kept away from mosquitoes, then the spread of dengue will eventually come to a close.
When dengue first broke out, I wasn’t really alarmed. After all, there were so many national and international public health institutions associated with the government who were working in Bangladesh. I had full faith in them.
Then things slid from bad to worse. There was no effective work plan in sight.
I had some expertise in such situations. I worked on various USAID projects for around eight years where I had the opportunity to participate in various workshops and training programmes pertaining to GIS, demographic analysis, data presentation, etc. Armed with such experience, I felt I had a degree of responsibility too. After all, it was my country too and so I took up voluntary work in this regard.
On 4 August I posted a Facebook status: “If any government or non-government organisation can collect the addresses of dengue-affected persons, I will do the rest as a volunteer.”
An old colleague drew the attention of Dhaka North City Corporation (DNCC) to my status and that evening the information officer of the city corporation called me over to discuss the details of what I wanted to do. I went over and spoke about drawing up a map to identify the localities in Dhaka where the incidence of dengue was higher and also to locate the sources of dengue. Measures would then be taken accordingly. They were eager to work with me, but that evening we couldn’t finalise how to collect the data.
I understood that it would not be easy to collect details about the dengue patients, particularly their addresses. On my way home I began formulating a back-up plan about using a form to collect data through crowdsourcing. I went home and that night prepared a form to collect information online, then shared it on Facebook. The next day it went viral and with the data received by the next day, I prepared an initial map.
Over a span of four days, till 9 August, 245 persons had provided information. Of them, 25 provided insufficient and inaccurate information from which I couldn’t pinpoint the exact locations. I dropped these 25 from my study.
According to the information received through crowdsourcing, till the day before Eid the most dengue-prone area was from Dhanmondi to Shahbagh, via Green Road. Next was from Niketon to Badda. And then was Basundhara residential area and Uttara. Outside of that, dengue appeared in most other areas too, in varying degrees. But over a span of 7 days, there most dengue-affected persons were in these 4 locations.
It is now imperative to take steps to immediately destroy the Aedes mosquito breeding sites in the areas marked in red. The city corporation can involve the local people in the task. This will make the task relatively easier.
From the perspective of a medical anthropologist, I noted that the number of hospitals was higher in the areas with higher incidence of dengue. I inquired at two hospitals and learnt that it was not possible for them to provide mosquito nets to all the patients.
It wasn’t enough just to clear away water from flowerpots and old tyres. It was essential to ensure that the dengue patients in hospitals were kept under mosquito nets. Those undergoing treatment at home also would have to be kept away from mosquitoes.
Over the Eid holidays, many have travelled home with dengue fever. That causes further fear of the virus spreading there. Here too it is imperative to keep the dengue patient away from mosquitoes.
It is important to take up a long-term plan to prevent any such outbreak in the future. There should be a central control and an efficient data collection system. The city corporations’ health department can use dynamic dashboards to study graphs and maps and take action accordingly.
I extend my sincerest thanks to those who helped in sharing the forms and providing information.
*Atik Ahsan is a medical anthropologist and former senior research investigator of icddr,b. This piece appeared in Prothom Alo online and has been rewritten in English by Ayesha Kabir