Dengue Update: Is Sri Lanka winning the war?

Worrying trends

Until recently  the number of reported dengue cases in Sri Lanka has been increasing at an alarming rate; this chart only goes up to 2013. The upward trend is steep especially when you add in the 2014 figure: 47502!

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Of those cases by far the majority were reported in Western Province (the most densely populated region of Sri Lanka).

For those living in Colombo the growth of Dengue has been particularly worrying. In 2010 there were just under 6,000 cases reported in Colombo. That rose to 10,000 in 2012 and, worryingly, 14,700 in 2014; that is 30% of all cases reported on the island.

For an up to date count of cases check out Dengue Count

Getting better?

However, this year the trend has been reversed; in 2015 there were 29777 reported cases. The number of cases in Colombo is down below 10,000; again good news although the city still accounts  for over 30%  of all cases.

So what went wrong in the past?

Reading back over some references I came across an article in the Sunday Times which probably sums up the problems of the past. These are just some of the points the journalists made

  1. There is no coordination among all relevant authorities on this issue of national importance and only ad hoc programmes are carried out whenever there is a crisis, was the view expressed by many including the public.
  2. Assistant Secretary of Government Medical Officers’ Association (GMOA) Dr. Upul Gunasekara said in the report that the Dengue Control Act, though brought in with good intentions was not practical. “There seems to be an administrative failure,” he said, adding that authorities such as the Ministries of Local Government, Environment and Education should be part of the group. “MOHs and PHIs can educate the public, but the local bodies must clear the garbage, the environment authorities must find solutions to the rubbish issue and the education authorities must chip in and instruct schools on a routine basis about cleanliness.

I remember when I researched  an article on Dengue for Geographical Review in 2012 it seemed to me that dengue controls were not being enforced; newspapers routinely reported that landowners, schools, commercial premises and households either ignored advice or flouted the law. I was told of operatives in Kotte who were selling off the insecticides to the highest bidder or charging exorbitant amounts to spray neighbourhoods. Routine fogging was noticeable by its absence

and what may be going right now?

But maybe things have turned around?  One years’ figures prove very little but if the downward trend is maintained much credit will be due to the Epidemiology Unit of the Ministry of Health, and the Centre for Dengue Research.

There is a lot of work ongoing which is aimed at dealing with dengue. There are two strands to this work;

  • dealing with the mosquito and its breeding grounds
  • trying to find a way to immunise the population; a dengue jab if you like

The use of insecticides and routine fogging are commonplace but on their own they cannot control the mosquito; to do that as everyone knows you need to remove the breeding grounds and there has been a lot of public information put out there;

top5breedingsports

Getting people engaged is the key; what excites me is that G.I.S. mapping is now being used on an extensive basis to build a detailed picture of dengue: where cases occur, how many cases and so on. in Sri Lanka (other countries as well)

It goes like this;

  1. first map the location of all newly reported cases of Dengue using GIS technology
  2. Identify hotspots of dengue from the maps
  3. make site visits to the hotspot areas and try to identify where the main mosquito breeding areas are
  4. take steps to destroy the breeding areas; enforce where necessary the law in relation to dengue control

I first came across this idea in a paper written in 2008. You can find details here. Researchers visited Kadugannawa near Kandy where dengue was endemic. They used GIS and GPS technology to locate and map dengue hotspots, create risk maps and to  use various vector control methods on the mosquito population. As a result the incidence of dengue fever reduced.

Now it seems the Centre for Dengue Research has taken this further: they are carrying out two related projects:

  1. Geospatial mapping of dengue transmission in the Colombo district
  2. Defining environmental factors that affect dengue transmission

and they have come up with a set of maps which show for the first time where the dengue hotspots are; check this out.

 

img-gis1

using these maps the group have been able to produce a “hotspot” map see below

img-gis2

you can see how the hotspots which have been identified are the same for each time period; that in turn means that the can produce a kind of risk map for Colombo

 img-gis4

Armed with that information the authorities can focus on the key problem areas and to control the breeding sites of the mosquito.

Like I said; information is the key!

Mo buzz; using the power of social media

and check out this: using the power of social media The Colombo Municipal Council’s Public Health Department along with Sri Lanka Telecom Mobitel, the Nanyang Technological University, Singapore (NTU) and the University of Colombo, School of Computing (UCSC) launched the ‘Mo-Buzz Dengue’ App. So now anyone can use the Android-based Mo-Buzz Dengue application to send a complaint about mosquito breeding sites to the CMC  by taking and sending a picture of the breeding site using the app, which automatically transmits the location of the complaint to the CMC, who can then deal with the problem.

if you haven’t already you should check out MO Buzz at http://www.mo-buzz.org/srilanka/

Getting people engaged in the fight mobilising the power of social media, coming down hard on those who ignore or flout the law, getting the information out there to the people so they can take the steps they need to control the mosquito.. that is what it is really all about.

It is too early to say whether the Sri Lankan authorities are getting the upper hand but the signs are promising. The authorities are taking the issue of dengue seriously now, and although dengue fever is unlikely to be eradicated any more than influenza will disappear from the UK, there is some hope that it is being brought under control.

Footnote: I spoke to a senior epidemiologist at the Centre for Dengue Research recently. She cautioned not to read too much into one year’s data. Often a bad year is followed by a year when the number of reported cases falls. This year (2016) so far there have been just over 9700 cases reported a little less than last year but.. in Colombo the numbers are 300 higher than 2015, and locally the authorities warn of a new epidemic, so maybe the disease is fighting back. It seems we will need to wait to see how 2016 pans out before we can start thinking about any real progress in the fight to contain dengue.

See also the latest article.. Dengue Count; Sri Lanka

In the meantime check out Newsfirst : http://newsfirst.lk/english/2016/01/dengue-outbreak-in-colombo-health-ministry-warns-public/125976

 

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