Fogging for Dengue: Does it Work?

Dengue fever poses a significant health risk in many regions. Dengue fever, which is caused by the dengue virus, is spread through mosquitoes. Therefore, one of the many ways to control the spread of dengue is to reduce the population of mosquitoes. Fogging is one of many methods used to control mosquito populations. In this article, we will delve into the intricacies of fogging for dengue, exploring its effectiveness and best practices. Let's get started!

Why is Fogging Necessary?

Fogging provides a swift and targeted approach to controlling adult mosquito populations.¹ The fine mist of insecticides effectively reaches inaccessible areas, reducing the number of disease- carrying mosquitoes in a short period.²

Fogging is able to cover expansive areas efficiently making it useful in urban settings like cities.

As fogging reduces the number of mosquitoes in an area, it is a valuable tool in emergencies, such as dengue outbreaks.³ Its quick deployment can help contain the spread of the disease, protecting communities from a sudden surge in mosquito activity thereby reducing the spread of dengue.^3 4

What Is Used for Fogging?

The insecticides used in fogging are formulated specifically for targeting flying adult mosquitoes.¹ They are different from typical cockroach sprays, which are designed for crawling insects like cockroaches. The main difference lies in how the insecticide is applied and the type of insects it's meant to control.

Health Implications of Fogging 

Inhaling the vapour from fogging insecticides can potentially cause health concerns such as⁵:

• Respiratory Irritation: Inhaling vapours may irritate the respiratory system, leading to coughing, wheezing, or shortness of breath, especially for those with existing respiratory conditions like asthma.
• Eye and Skin Irritation: Direct contact with the mist may cause irritation to the eyes and skin. It's important to avoid exposure by staying indoors during fogging operations and keeping windows closed.

To minimise health risks, follow advice from local authorities on how to protect yourself during fogging operations. This might include staying indoors, covering food and water sources, and keeping pets away from treated areas.

Best Practices for Dengue Fogging

• Timing and Frequency

Effective fogging requires strategic timing. It is most beneficial during periods of high mosquito activity, typically early morning or late evening.⁶ 

The best time to use insecticide fogging to reduce dengue cases is early in the wet season, before the peak of the outbreak. By starting fogging early, we can slow down the spread of dengue and prevent the number of cases from reaching high levels during the rainy season. This approach is more effective than waiting until the outbreak is at its worst. It's important to consider seasonal changes and plan fogging accordingly to control dengue better in endemic areas.⁶ 

• Choosing the Right Insecticide

Selecting the appropriate insecticide is critical. The choice depends on the specific mosquito species prevalent in the area. Consulting with local health authorities or pest control experts can help determine the most effective solution.

Challenges and Considerations of Fogging for Dengue Prevention

1. Environmental Impact

The use of insecticides in fogging raises concerns about its environmental impact.⁷ It is crucial to choose insecticides carefully, opting for formulations that are less harmful to non-target organisms and ecosystems.⁷

2. Weather Dependency

The effectiveness of fogging is influenced by weather conditions such as wind speed, temperature, and humidity.⁸ Unfavourable weather may limit the dispersal of insecticides, affecting the overall success of mosquito control efforts.⁸

3. Insecticide Resistance

Over time, mosquitoes can develop resistance to the chemicals used in fogging.⁹ This poses a significant challenge, necessitating continuous research and adaptation of insecticide formulations to maintain their effectiveness.⁹

4. Community Awareness and Cooperation

Successful fogging campaigns rely on community awareness and cooperation.10 Educating the public about the importance of fogging, addressing concerns, and obtaining support for preventive measures are vital for the sustained success of dengue prevention initiatives.¹⁰

5. Immediate Treatment vs. Long-Term Solutions

Fogging is effective for rapidly reducing adult mosquito populations, but it's a short-term solution. By complementing fogging with long-term preventive measures like habitat removal, communities can better manage and reduce dengue transmission over time.⁹

Fogging as a Crucial Tool in Dengue Prevention

In summary, fogging is a powerful tool in the fight against dengue fever, swiftly controlling mosquito populations. Despite its benefits, fogging creates challenges like environmental impact and insecticide resistance. To succeed, it requires careful insecticide selection, community awareness, and adaptability to changing conditions. Balancing effectiveness with environmental considerations is crucial for ongoing success in preventing dengue outbreaks.

References

1. “Mosquito 'fogging' will not harm you, reminds WHO and Solomon Islands Ministry of Health.” World Health Organization (WHO), 5 May 2014, https://www.who.int/westernpacific/about/how-we-work/pacific-support/news/detail/05-05-2014-mosquito-fogging-will-not-harm-you-reminds-who-and-solomon-islands-ministry-of-health. Accessed 22 January 2024.
   
   
2. “Fogging to combat dengue: factors influencing stakeholders' attitudes in Malaysia - BMC Public Health.” BMC Public Health, 14 June 2023, https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-023-16054-3. Accessed 22 January 2024.
   
   
3. “Operational guidelines for Dengue prevention and control in emergency situation.” National Dengue Control Unit, https://www.dengue.health.gov.lk/web/index.php/ta/new-circular?download=49:operational-guidelines-for-dengue-prevention-and-control-in-emergency-situations. Diakses pada 22 January 2024.
   
   
4. K. G. Thilanka N, et al. “Effect of dengue mosquito control insecticide thermal fogging on non-target insects.” Springer Link, https://link.springer.com/article/10.1017/S1742758416000254. Accessed 22 January 2024.
   
   
5. O'Malley, Gerald F., and Rika O'Malley. “Insecticide Poisoning - Injuries and Poisoning - MSD Manual Consumer Version.” MSD Manuals, https://www.msdmanuals.com/home/injuries-and-poisoning/poisoning/insecticide-poisoning. Accessed 2 May 2024.
   
   
6. “Optimal Timing of Insecticide Fogging to Minimize Dengue Cases: Modeling Dengue Transmission among Various Seasonalities and Transmission Intensities.” NCBI, 25 October 2011, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3201920/. Diakses pada 22 January 2024.
   
   
7.  “Impact of pesticides use in agriculture: their benefits and hazards.” NCBI, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2984095/. Accessed 22 January 2024.
   
   
8. “Influence of climate change and pesticide use practices on the ecological risks of pesticides in a protected Mediterranean wetland: A Bayesian network approach.” ScienceDirect, https://www.sciencedirect.com/science/article/pii/S0048969723016364. Accessed 23 January 2024.
   
   
9.  “NEA | Fogging should be used judiciously and not as a routine mosquito-control measure.” The National Environment Agency, 13 June 2022, https://www.nea.gov.sg/media/readers-letters/index/fogging-should-be-used-judiciously-and-not-as-a-routine-mosquito-control-measure. Accessed 23 January 2024.
   
   
10. “Practices of Dengue Fever Prevention and the Associated Factors among the Orang Asli in Peninsular Malaysia.” PLOS, https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0003954. Accessed 23 January 2024.

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

Disclaimer: 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.

These images depict hypothetical patients and/or healthcare professionals.

C-ANPROM/MY/DENV/0285 May 2024