Stop the Dengue Spread: Avoid Getting Infected!

Dengue fever is a viral illness with potentially severe consequences such as dengue haemorrhagic fever. It is primarily transmitted through mosquito bites and in more rare cases via maternal transmission or other transmission modes.1 2

Why should we learn about these transmission methods? It allows us to prevent the spread of dengue outbreaks caused by mosquitoes infected with the dengue virus. 

How Dengue Spreads Through a Bite

Dengue is transmitted through the bite of an infected mosquito, primarily the Aedes aegypti and Aedes albopictus mosquitoes which have been identified in numerous urban areas across Southeast Asia, including Malaysia.^1,3

A person with dengue virus in their bloodstream gets bitten by an Aedes mosquito.¹ After about a week, the mosquito can transmit the virus while biting a healthy person.⁴ 

Despite their ability to fly up to 400 metres in search of water-filled containers to lay eggs, Aedes aegypti mosquitoes often remain close to human habitats.⁴ 

While humans cannot pass dengue infections directly to one another, an infected individual can transmit the virus to other mosquitoes.⁴

From Mother to Child: Infected at Birth

The primary route for transmitting dengue virus among humans is through mosquitoes. Nonetheless, there is indication that maternal transmission from a pregnant mother to her baby is possible. However, the rates of such transmission seem to be low, and the risk appears to be associated with the timing of the mother's dengue infection during pregnancy. If a mother is infected with DENV during pregnancy, it may lead to adverse outcomes such as pre-term birth, low birthweight, and foetal distress.¹

Dengue Transmission in Healthcare Settings

Apart from mosquito-borne transmission, dengue can also surprise us by spreading through infected blood and in healthcare settings, though it's important to note that this mode of transmission is rare.¹Nosocomial transmission refers to the infection's spread within healthcare environments, and it can occur via:⁵ 

• Blood transfusion
• Needle stick injuries
• Skin or mucous membrane exposure to blood

A stark example from South Korea in 2014 revealed how a laboratory worker, despite working in a well-controlled laboratory environment, contracted dengue through a needle stick injury7. Symptoms such as muscle pains, vomiting, chills, and fever emerged quickly.⁶

Another example that highlights the need for vigilance in the healthcare sector occurred in Singapore, involving a frequent blood donor who had dengue but was asymptomatic. Subsequent investigations revealed that recipients of the donor's blood products also tested positive for dengue virus type 2 (DENV2).⁷

Preventing Dengue: Strategies for Protection

To combat the dengue infection, it is vital to adopt preventative measures that encompass both personal responsibility and community-level action. These include:⁸

• Eliminate Breeding Sites: Regularly inspect your surroundings and eradicate any stagnant water where mosquitoes can breed. This includes flower pots, tires, and containers. 
• Use Mosquito Repellent: Apply mosquito repellent containing DEET when venturing outdoors, especially during peak mosquito activity times. 
• Wear Protective Clothing: Use long-sleeved shirts and pants to reduce exposure to mosquito bites.
• Install Screen Windows and Doors: Put up screens on windows and doors to keep mosquitoes out of your home.

In Summary

In conclusion, dengue fever is a serious viral illness with distinct modes of transmission, each demanding our attention and vigilance. Let us take collective responsibility for dengue prevention, from personal actions to community-level initiatives.

By understanding the dengue virus transmission and embracing preventive strategies, we can work together to reduce the impact of this debilitating disease on our communities and protect our loved ones.

References

1. Centers for Disease Control and Prevention. (2019). Dengue transmission. Retrieved September 27, 2023, from CDC: https://www.cdc.gov/dengue/transmission/index.html
2. WHO. “Dengue and severe dengue.”17 March 2023, Retrieved December 1, 2023 from World Health Organization (WHO): https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue
3. Zainon, N., Mohd Rahim, F. A., Roslan, D., & Abd-Samat, A. H. (2016). Prevention of Aedes Breeding Habitats for Urban High-rise Building in Malaysia. Journal of the Malaysian Institute of Planners, 5, 115–128. https://doi.org/10.21837/pmjournal.v14.i5.197 
4. World Health Organization. (2019). Dengue and severe dengue. Retrieved September 27, 2023, from WHO: https://www.who.int/news-room/questions-and-answers/item/dengue-and-severe-dengue
5. Almeida-Nunes, J., Marcilio, I., Oliveira, M. S., Gonçalves, E. M., Batista, M. V., Mendrone, A., Levi, J. E., Costa, S. F., & Levin, A. S. (2016). Hospital-Acquired Vector-Transmitted Dengue Fever: An Overlooked Problem?. Infection Control and Hospital Epidemiology, 37(11), 1387–1389. https://doi.org/10.1017/ice.2016.173
   
6. Lee, C., Jang, E. J., Kwon, D., Choi, H., Park, J. W., & Bae, G. R. (2016). Laboratory-acquired Dengue Virus Infection by Needlestick Injury: A Case Report, South Korea, 2014. Annals of occupational and environmental medicine, 28, 16. https://doi.org/10.1186/s40557-016-0104-5
   
7. The New England Journal of Medicine. “Dengue Hemorrhagic Fever Transmitted by Blood Transfusion.” Accessed 21 February 2024. https://www.nejm.org/doi/full/10.1056/nejmc0708673#:~:text=A%2052%2Dyear,reaction%20(PCR)%20assay
   
8. Centers for Disease Control and Prevention. (2023). Avoid Dengue by Preventing Mosquito Bites. Retrieved September 27, 2023, from CDC: https://www.cdc.gov/ncezid/dvbd/media/avoid-dengue.html
   
9. WHO “WHO recommends R21/Matrix-M vaccine for malaria prevention in updated advice on immunization.”, 2 October 2023, Retrieved December 1, 2023 from World Health Organization (WHO): https://www.who.int/news/item/02-10-2023-who-recommends-r21-matrix-m-vaccine-for-malaria-prevention-in-updated-advice-on-immunization. 

This article is brought to you by Takeda Malaysia Sdn. Bhd. 200901025887 (868989-K)

Disclaimer: These images depict hypothetical patients and/or healthcare professionals. This information is available to the public for information purposes only; it should not be used for diagnosing or treating a health problem or disease. It is not intended to substitute consultation with a healthcare provider. Please consult your healthcare provider for advice.

C-ANPROM/MY/DENV/0262 FEB 2024