23 Jan 2017


Q1. Is Wolbachia a GMO?

No, Wolbachia has not been genetically modified, and is classed as a biological control agent. It already exists in the environment naturally (within invertebrate hosts). It is also not being used as a biopesticide because we are not using it to suppress populations.

Q2. Do the Wolbachia strains that will be released occur naturally in Malaysia?

Yes, in the common Drosophila fruit flies and in other mosquito species.

Q3. If Wolbachia occur naturally in Aedes albopictus, why don’t they block dengue transmission?

Natural Wolbachia strains occur at lower density and don’t have a big impact on virus transmission, while the introduced Wolbachia will be at much higher density within the mosquito cells and will block dengue.

Q4. Could Wolbachia increase transmission of some viruses?

Increased transmission efficiency of human viruses has never been observed for a stable mosquito Wolbachia infection; the viral inhibition seems to be a general effect for RNA viruses and occurs for both flaviviruses (including dengue) and alphaviruses (chikungunya)

Q5. Could the virus mutate to be transmitted efficiently by mosquitoes carrying the released Wolbachia?

This is unlikely as there are multiple mechanisms of viral blocking by Wolbachia within the mosquito cell, making the system naturally resistant to viral ‘escape’ mutations. There is no evidence to date of viruses having evolved in this way.

Q6. Could Wolbachia be transmitted to humans?

No, Wolbachia or Wolbachia proteins are not transmitted in mosquito saliva. These Wolbachia can only grow in insect cells; no Wolbachia can survive / grow in vertebrate cells. Humans have been exposed to Wolbachia in countless ways for millions of years and there is no evidence that there has ever been transmission to humans.

Q7. Could Wolbachia cause ecological damage in the environment?

No, Wolbachia can only survive and replicate inside host invertebrate cells, they do not escape and cause damage.

Q8. Does Wolbachia infect or cause damage to other insects?

Wolbachia is only transmitted from mother to offspring and so it is impossible for Wolbachia to spread into other insects. Furthermore, the Wolbachia strains to be used are already common in fly fruits/ other mosquitoes and will not cause ecological damage to the host insect.

Q9. Why do female mosquitoes have to be released?

Wolbachia spread is dependent on female release because it is transmitted by the females and not the males. So only by releasing females will the Wolbachia be introduced into a population.

Q10. Why not just release the males to suppress the mosquito population?

This is a much less efficient strategy that requires ongoing intervention with a much larger scale of release. It would have to be conducted continuously to have any effect on dengue transmission and so would be very expensive. As soon as male releases are stopped, the mosquito population bounce back. In contrast, the replacement strategy requires just a short period of releasing relatively small number of mosquitoes, and then Wolbachia spreads by itself.

Q11. I heard that Singapore is releasing the male? Why can’t we do the same?

Singapore is releasing the males in a huge scale to study whether the techniques are able to suppress the population. This might have an effect when mosquito densities are very low as they are in Singapore, but is not feasible for a large area such as in Malaysia, and requires a very large number of mosquitoes to be produced.

Q12. Would people notice an increase in mosquito biting?

The mosquitoes are released in a short period and the released males would be sterilizing wild females. Any increase if detected at all would only be minor. Plus, the wild mosquito populations will be reduced by fogging before release.

Q13. Will the public support releases?

Careful community engagement and education will be conducted at each site prior to any releases. Initial survey also showed that the locals support the release of Wolbachia mosquitoes.

Q14. What happens if individuals / families are opposed to releases?

They can be given a ‘veto’ and releases would not be conducted near their homes.

Q15. When can we expect to see dengue suppression occurring?

This will happen when all the wild Aedes population in the treated site is infected with Wolbachia.

Q16. How long will the Wolbachia effects last?

Their effects are permanent. Mosquitoes will stay infected with Wolbachia, it is a self-maintaining control method.

Q17. Can we still undertake our usual mosquito suppression measures while releases are occurring?

Yes. All normal methods of mosquito control like suppressing breeding sites continue while releases are undertaken.

Q18. What happens when there is a dengue outbreak in the area where releases are being undertaken?

Because the Wolbachia infected mosquitoes block dengue transmission, releases could continue, but this will be up to the community. They can also be stopped in a local area for a period.

Q19. Why don’t you start releases first in field cages?

Wolbachia have already been shown to invade field cages successfully many times, so these experiments do not provide any new information. Moreover, Wolbachia have now been released successfully in many countries without any issues and they are already present naturally in the environment in many insects.

Q20. Why we do not implement this research earlier if the results are encouraging?

This technique has been used by other countries namely, Australia, Brazil, Columbia, China, French Polynesia, Indonesia, Singapore, Thailand and Vietnam. Malaysia decided to apply this technique because the outcome of the research in these countries is encouraging.

Q21. How many mosquitoes will be released into the population?

The number of mosquitoes that shall be released will be based upon the density of mosquitoes in the area..

Q22. How do we control the mosquitoes if the dengue cases arise?

Conventional vector control measures such as fogging will be conducted concurrently with the release of Wolbachia mosquito at the area of study.

Q23. Would these viruses (dengue, Zika & chikungunya) survive after Wolbachia has been injected into the mosquito?

Wolbachia bacteria are able to stop the growth of dengue, Zika & chikungunya virus. Hence these viruses will not be able to grow and survive.

Q24. Why Wolbachia are not injected directly into the human body?

Wolbachia bacteria require insect as their host since it is unable to live inside human body. Therefore, injecting Wolbachia directly into the human body would not restrain the spreading of dengue, Zika and chikungunya.

Q25. For how long this duration of the Wolbachia mosquito suppression/release program will take?

The research is expected to run until the year 2020. If the research data are positive, the technique will be implemented throughout the nation. However, for the time being, we will only focus on AU2 and Seksyen.7.

Q26.How long do mosquito live?

The lab strain mosquitos are able to live for up to a month given the right conditions. The wild mosquito will normally survive around 7-10 days. This was proven by a research.

Q27. Can dengue virus mutate when interacting with the Wolbachia?

This is unlikely as there is multiple mechanisms of viral blocking by Wolbachia within the mosquito cells. There is no evidence to date of viruses having evolved in this way.

Q28. How can we be sure that the mosquito carries Wolbachia? Is there any difference on the physical appreance of the mosquito?

IMR will recapture the mosquitoes and screen them in the laboratory to ensure that the Wolbachia is present. There is no physical difference that can be seen on mosquito carrying Wolbachia.

Q29. Will we only inject the male mosquito with Wolbachia?

Since we choose the “Population Replacement” technique, both male and female will be injected with Wolbachia.

Q30. If these mosquitoes already carrying Wolbachia, does that mean we will not have problem with the virus anymore?

Theorically, the presence of Wolbachia in Aedes aegypti and Aedes albopictus would restrain dengue, Zika and chikungunya viruses from spreading.

Q31. How effective is this programme and why don’t we just use other country’s data? Is the geography and climate are contributing factors?

Till 2017, nine countries have succesfully implementing this programme. Australia and Vietnam have  reported that the treated area is free from dengue cases.

Q32. What is the the difference between Wolbachia mosquito and GM mosquitoes that was released in Bentong?

There is a significant difference between GM mosquito and Wolbachia mosquito. GM mosquito is genetically modified, while the Wolbachia mosquito uses bacteria naturally found in almost 60% of insects.

Q33. Is it true that the mosquito eggs will be injected with Wolbachia in United Kingdom?

Yes. However, these eggs are originally collected from our local Aedes mosquitoes bred in Institute for Medical Research (IMR) before they were sent to United Kingdom.

Q34. What happen if Wolbachia mosquito bite human?

The Wolbachia mosquito bites are pretty much the same as wild mosquito but without the risk of dengue infection.

Q35. Why these mosquitoes only breed in clean stagnant water?

Aedes aegypti naturally requires clean water to breed.

Q36. If release programme is done in 2017, what is the effectiveness of the release?

It is going to take a while for us to see the effect. When the Wolbachia mosquitoes successfully take over the wild population, the dengue cases is expected to decrease.

Q37. Is there any side effect of Wolbachia mosquitoes?

After 6 years of release programme in Australia, there is still no side effect ever reported.

Q38. Why is this programme taking long time to be implemented?

Agreement, commitment and good understanding from all parties are essential and a must especially from the residents in the study field to be evaluated before the release may be executed.

Q39. Are we going to breed all species of mosquito for this project?

No. Only two species of mosquito (Aedes aegypti and Aedes albopictus) will be bred for this project because they are the vectors of the dengue, Zika and chikungunya virus.

Q40. Is there any scientific evidence to show the success of this programme?

There are a number of studies and scientific journals showing the application of Wolbachia is able to restrain dengue, Zika and chikungunya.

Q41. Why AU2 and Seksyen 7 are choosen as the place of study for this research?

There are few criteria to select the place as an area of study:

  1. Dengue “Hotspot”.
  2. Both Aedes aegypti and Aedes albopictus are present.
  3. Close to IMR, for logistic consideration.
  4.   Total area of 0.60km2

Q42. If this programme is a success, why we don’t apply it throughout the nation?

Eventhough this project is a huge success in other countries; we still need our own data to confirm its efficacy before implementing it thoroughly.

Q43. What would happen to the Wolbachia mosquito if the fogging took place?

Like any wild mosquito, Wolbachia mosquito will die as well when fogging is carried out.

Q44. Do the resicence still need to undertake precautionary steps while releases are occurring?

All normal methods of mosquito control continue while releases are undeway.

Q45. What is the duration of the release?

The mosquitoes will be released for  up to 10 weeks. Then, the density of Wolbachia mosquitoes will be screened until we have reached the desired target.

Q46. Does the presence of Wolbachia affect the interaction between mosquito and its natural predator?

The interaction between mosquito and its natural predator are not affected in the presence of Wolbachia.

Q47. Did Myanmar use Wolbachia to control mosquito?

Yes. The house mosquito Culex pipiens fatigans was controlled using the Population Suppression technique and the finding had been published.

Q48. You mentioned that Wolbachia mosquitoes will be released until 60% of the wild mosquito population carry Wolbachia. How do you confirm this?

Ovitraps (mosquito larval traps) will be setup to obtain wild mosquito eggs which will be hatched to obtain larvae. Screening will be conducted in laboratory to determine the density of Wolbachia in these larvae.

Q49. Do Wolbachia affect the flying radius of the mosquito?

The flying distance of Wolbachia mosquito is similar to wild mosquito.

Q50. If the eggs are stored in a dry place, how long can the Wolbachia last?

The Aedes eggs that contain Wolbachia can be stored for up to 6 months, since dried Aedes eggs remain viable up to 6 months. After 6 months, these eggs will be discarded.

Q51. Who will be responsible if something is going wrong? Is it IMR or IPTK?

Every research project has to go through the Medical Research & Ethics Committee (MREC) under the supervision of Health Ministry. Any problem that arises from the research will be handled by the Health Ministry.

Q52. What happened when Wolbachia are injected into the eggs/body of the mosquito?

The mosquitoes developed from the injected eggs will carry Wolbachia. When the female Wolbachia mosquito mate with wild male mosquito, Wolbachia will be transferred to the offspring. The presence of Wolbachia will stop the growth of dengue, Zika and chikungunya.

Q53. If there is a breeding site at the resident/construction area, will the owner be fined for breeding mosquitoes?

During the release programme, the residents will not be fined if breeding is found. However, it is recommended that the resident destroy any mosquito breeding sites.

Q54. Will they release the mosquito into the house/water tank?

The adult Wolbachia mosquitoes will only be released outside the house.

Q55. Can we stop the fogging/cleaning activity after this programme took place?

The vector control activities should be done on a regular basis.

Q56. Will the mosquitoes die if sprayed with aerosol pesticide?

The Wolbachia mosquitoes will die because of the insecticide, just like any other mosquitoes.

Q57. Is the Wolbachia mosquito active like any other mosquitoes?

The behaviour of Wolbachia mosquito is exactly the same as the wild mosquito. There is no different on physical features or behaviour that can be observed.

Q58.Have other countries implemented this research technique?

There are few ongoing researches in countries such as Australia, Singapore and Indonesia. In fact, Australia has conducted this research for more than 6 years.

Q59. When will this mosquito be released?

The mosquito is expected to be released in March 2017.