Dengue Outbreak 2019 – Making Sense Of The Data

Comparing rates gives us a better idea of how different states are coping with dengue.

Dengue epidemics have been growing in size over the years. It is important that, as we look at the problem, our print and electronic mainstream media improve the quality of data and analysis to support public change and response.

The media is fond of highlighting states where there are larger numbers of a negative event occurring.

While numbers are very important, it is equally vital that the media take the effort to reflect the change over time and the occurrence of events by rates. Rates allow for a more meaningful comparison between regions because they take into account the population base for that state.

Allow me to take the current epidemic rise in dengue cases reported in the country as an example for us to learn from.

The table below shows the cumulative cases of reported dengue up to Week 29 of 2019, which ends 20th July.

As the media clearly points out, we have a significant rise in the number of dengue cases in the nation; a 89% increase from the previous year for the same period. Perhaps what is not highlighted is that this increase is not uniform through the country.

Note that by calculating the change for the previous year (see the ‘increase over previous year’ column) you can appreciate that some states are having an enormous outbreak, while others have not had a significant increase. In particular Kelantan (315% increase), Melaka (294% increase), Sarawak (258% increase) Terengganu (157% increase) and WP KL/Putrajaya (152% increase) are doing very poorly. Selangor, Negeri Sembilan, Johor and Pahang are also under-performing. But Kedah, Perak and WP Labuan are doing much better.

Comparing numerical change over time tells about changing epidemic size in that state and performance.

But we should also compare rates to get a true idea of the severity of the epidemic in each state.

Rates show that Selangor and WP KL/Putrajaya are having enormous epidemics compared to the rest of the country, four to six times the size of the other regions. Penang, Negeri Sembilan, Melaka, Johor and Kelantan are also not doing well, looking at their rates.

Table: Reported Dengue Cases, Cumulative Cases up to Week 29 of 2019 (20th July), Malaysia
StateCumulative Cases up to Week 29 of 2019 (20th July)*Comparison with
Cumulative Cases up to Week 29 of 2018 (20th July)*
Increase over Previous YearPopulation 2018#Rate of Reported Dengue per 100,000 population for Cases up to Week 29 of 2019 (20th July)*
WP KL & Putrajaya8,7943,488152%1,795,700489.7
N. Sembilan1,37074684%1,134,100120.8
WP Labuan2466-64%99,60024.1

* Source: CPRC Kebangsaan, Ministry of Health, Malaysia (Facebook page)

# Demographic Statistics, Department of Statistics, Malaysia (Note that numbers were rounded up in the source)

It is important that our government agencies display crucial data both as numbers, rates and trends (change) over time so the public can be better informed and respond appropriately.

This data then should then elicit responses that include:

  1. We should question the accuracy and completeness of the reports in each region. Reports of deaths (not shown here) could be a proxy indicator of epidemic severity in a state that has poor reporting. For example Sabah has a relatively low rate but has had 15 dengue deaths so far (third highest) and this warrants an evaluation and explanation.
  2. If reporting is good (as I know it is in Perak), we should ask why some states can do better and learn from them.
  3. It must be recognised that dengue is cyclical and every three to five years we will have larger epidemics (possibly when immunity wanes). Hence our response must take into account the larger picture of this cycle.
  4. Finally we cannot run away from the responsibility of the individual. Dengue spreads because of human behaviour. Our collective response as members of the public can help to halt and reduce this epidemic.

The media, whether print or electronic, play an important role in our lives and we value them. I implore our media to better report data in our country.

Reporting rates is vital in any problem that has large numbers over many regions. This will elevate the standard of our reporting and dialogue.

Dr Amar-Singh HSS is Advisor of the National Early Childhood Intervention Council (NECIC). He was previously a Senior Consultant Paediatrician and Head of the Paediatric Department, Hospital Raja Permaisuri Bainun, Ipoh. Recently retired, he worked in the public healthcare sector for over 36 years.

  • This is the personal opinion of the writer or publication and does not necessarily represent the views of CodeBlue.

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