1. SOME MOSQUITO FACTS!
Female Ae. aegypti. Lateral view
MOSQUITO
- The word
"mosquito" originated from the Spanish words "muscato",
"muskitto" or "musqueto" to mean "small fly"
- Their
importance is not known except that they BITE!
- Patrick Mason
first discovered that mosquitoes – the Culex quinquefasciatus –
can transmit filariasis, a parasitic disease, in 1878
- Ronald Ross
discovered the malaria parasite in Anopheline mosquitoes in
1897
- Colonel
Walter Wright discovered that Ae. aegypti (Aedes aegypti)
can transmit yellow fever in 1900
- The male
mosquito is smaller than the female mosquito
Aedes aegypti (Male
on the left, Female on the right) Source: Wikipedia
Only female mosquitoes BITE!
Male mosquitoes do not bite or spread disease as they do not have the
mouthparts to bite
Diseases transmitted by mosquitoes in Malaysia : There are 5 human
diseases transmitted by mosquitoes in Malaysia: Malaria, Dengue, Filariasis,
Japanese Encephalitis and Chikungunya.
The mosquito life cycle:
2. THE DENGUE SCOURGE
The incidence of dengue in Malaysia has been rising steadily, from 7,103
cases in 2000 to 46,171; including 134 deaths, in 2010 and the disease costs
the Malaysian economy between RM270 million and RM667 million per annum. In
light of this, the Malaysian government has identified dengue control as a
national priority.
Dengue has also put some 2.5 billion people in more than 100 countries
at risk.
At present, there is no effective vaccine or specific treatment for
dengue fever while current control methods (eg. larviciding, space spraying
with insecticides or fogging, public education or ComBI, legally enforced
breeding site reduction, etc.) have not stopped the spread of the disease. So
there is an urgent need to evaluate promising new technologies.
Source : National Enviroment Agency
2.1. Dengue
Dengue is transmitted by the bite of a female Aedes aegypti mosquito
infected with any one of four versions of the dengue virus and the major
source, or reservoir, of the virus is humans. The disease is transmitted when a
female Aedes aegypti mosquito bites an infected person and
then bites someone else. Symptoms appear within 3 – 14 days (average 4 – 7
days).
Classical dengue fever is a severe, flu-like illness that affects
infants, young children and adults. Dengue hemorrhagic fever is a potentially
lethal complication, particularly in children, and early clinical diagnosis and
careful clinical management by experienced physicians and nurses is necessary
to reduce the number of fatalities.
More than 70% of the global disease burden is in South-East Asia, Asia
and the Western Pacific areas. In Latin America and the Caribbean, the
incidence and severity of the disease are increasing rapidly while the USA,
Europe and the Eastern Mediterranean are much less affected. International air
travel is facilitating the rapid global movement of dengue viruses as it
increases the risk of dengue hemorrhagic fever epidemics by introducing new
dengue viruses into susceptible populations.
2.2. Chikungunya
Chikungunya is a viral disease. First observed in 1952 in Tanzania, the
name comes from the local Swahili dialect which means "that which bend
up" for the stooped walk that reflects the physique of a person suffering
from the disease.
Chikungunya (also known as chikungunya virus disease or chikungunya
fever) is a debilitating but usually non-fatal, viral illness that is spread by
the bite of infectedAedes aegypti mosquitoes. Its symptoms can
resemble those of dengue fever.
There is no specific treatment for chikungunya either. Supportive
therapy that helps ease symptoms; such as non-steroidal anti-inflammatory drugs
and getting plenty of rest, may be beneficial.
2.3. Yellow Fever
Also transmitted through the Aedes aegypti mosquito,
Yellow Fever displays similar symptoms to that of Dengue and Chikungunya and
although not very common in the Asian region, the risk of infection still
exists.
3. GENETICALLY-MODIFIED AEDES AEGYPTI RESEARCH
The Ministry of Health Malaysia (MoH) has been evaluating a promising
technology, called RIDL®, which involves genetically modified Aedes
aegypti male mosquitoes. Using genetically-modified male mosquitoes to
mate with the local Aedes aegypti mosquitoes means they will
not produce offspring that survive adulthood leading to a reduction in the
overall Aedes aegypti population. This technique is based on
the well-understood and tested concept known as Sterile Insect Technique. By
evaluating this technology in a methodical and step-wise manner, the Ministry
can assess its potential to be deployed as a long-term solution to controlling
dengue.
Source of information : http://biotechboffins.blogspot.com/2012_07_01_archive.html
3.1. How it all started
The genetically-modified Aedes aegypti OX513A mosquito
strain (OX513A) was originally developed at the University of Oxford, which
founded and part-owns Oxitec, a UK company. Upon the invitation of the MoH,
Oxitec transferred its lead strain of Aedes aegypti OX513A to
the Institute for Medical Research Malaysia (IMR) for independent evaluation in
2006. Since then, the IMR has successfully evaluated this new control
technology under laboratory and semi-field conditions. The technology has also
been evaluated by reputed institutes around the world including the Institut
Pasteur in Paris, France, and the WHO Collaborating Centre for the Ecology,
Taxonomy and Control of Vectors of Malaria, Filariasis & Dengue at the IMR
and so far, the results have been very encouraging.
Oxitec's genetically-modified technology is a genetic enhancement of the
well established sterile insect technique (SIT). SIT is used in large-scale
operational control or eradication programs against insect species of
agricultural importance, throughout the world, and is a technique which is
well-understood due to operational deployment spanning 50 years. Oxitec's-SIT
works by repeatedly releasing large numbers of (genetically) sterile male Ae.
aegypti mosquitoes in the area where control is desired. These
released sterile males compete with their wild male counterparts for available
wild female mating partners. Matings between OX513A sterile males and fertile
wild females produce no viable offspring. Successive releases quickly cause a
crash in the population level.
On the 20th of December, 2006 the Government of Malaysia and Oxitec
signed a Joint Initiative Agreement to undertake an evaluation on the latter's
technology in Malaysia. The evaluation was planned to be conducted in three
phases:
PHASE 1: Laboratory Studies [ COMPLETED]
PHASE 2: Contained Field Trials [COMPLETED]
PHASE 3: Open Field Release
3(a) MRR in uninhabited area - Bentong [COMPLETED]
3(b) MRR in inhabited area – to be conducted in Alor Gajah,
Melaka [To be conducted once all regulatory requirements met]
3(c) Suppression Trial [Currently undergoing institutional review
by IMR]
Cayman Islands and Brazil have already initiated Aedes aegypti OX513A
open field trials in inhabited areas under their respective local conditions as
a potential means to control the spread of dengue.
Link to Nature Biotechnology publication on the study in Cayman Island:
If the Aedes aegypti OX513A is successful in
eliminating local populations, then there would be a dramatic reduction in the
number of dengue cases and deaths in Malaysia, to the great benefit of not just
Malaysia, but other countries that are fighting this same scourge. The technology
is not seen as a standalone solution but as part of Integrated Vector
Management (IVM), as recommended by the World Health Organisation (WHO).
3.2. The first open trial in Malaysia -
limited 'mark-release-recapture' experiment
Permission was received from the National Biosafety Board, Ministry of
Natural Resources and Environment (NRE) for a limited mark-release-recapture
(MRR) experiment (NRE(S) 609 – 2/1/3) in October 2010. The limited release of
approximately 6,000 non-biting sterile male Aedes aegypti mosquitoes
from the OX513A strain was carried out on 21 December 2010 in an uninhabited
location in Hutan Tanah Kerajaan (Bukan Hutan Simpanan or Non-Reserved
Government Forested Land) off Jalan Tentera (off 'Lebuhraya Bentong-Raub') in
Daerah Bentong, Pahang, in the presence of representatives from the independent
monitor (Akademi Sains Malaysia) and the NRE to ensure compliance with the
terms and conditions associated with the approval from the NBB. The release
experiment was completed on 5 January 2011 and the area treated twice with
insecticide (fogged), as stipulated by the NBB.
The limited mark-release-recapture trial was to study the dispersal and
longevity of the Aedes aegypti OX513A mosquitoes in the field
and compare them with wild type male Aedes aegypti mosquitoes
(which were co-released for comparison), something which could not be
ascertained in a laboratory or a contained setting. This in turn, will provide
information to the IMR for the risk assessment and risk management of
subsequent trials, all of which will be subject to NBB approval.
Following are the chronology of events during the first open release
trial in uninhabited area in Bentong, Pahang.
15 December 2010
Mock-run, trial not conducted due to bad weather. Ministry of Natural
Resources and Environment (NRE) and independent monitor, Akademi Sains Malaysia
(ASM), were present.
21 December 2010
6,045 sterile (GM) males and 5,372 wild (Lab) males released at mid-day
in an insular, uninhabited non-reserve forest near Bentong. NRE and independent
monitor ASM were both present.
3-5 January 2011
No recaptures, so according to protocol, trial stopped on 5th.
6 & 18 January 2011
Pejabat Kesihatan Bentong conducts fogging as demanded by NBB.
14 February 2011
Weekly ovitrap monitoring (from 7 January 2011) completed.
Photos showing the Limited Mark Release Recapture Study in Uninhabited
Area in Bentong, Pahang:
Transporting the male Aedes
aegypti (L.) Wild Type
and OX153A strain mosquitoes to the
release point
Male mosquitoes were marked using florescent dye
In accordance with NRE guidelines, no further release will be carried
out until the post-trial monitoring is completed, and the results analysed and
presented in peer-reviewed scientific journals and/or meetings. In parallel,
the results will be presented to the independent monitor and the NBB for their
review.
3.3. The Next Step – Inhabited
'Mark-Release-Recapture' Experiment
The next step is the inhabited MRR experiment which will also entail the
release of approximately 6,000 non-biting sterile male Aedes aegypti mosquitoes
but in an inhabited location. Albeit IMR has researched over 50 sites
nationwide, timing and location of this next exercise will be dependent on
certain scientific requirements; such as the mosquito population dynamics, as
well as fulfilling the parameters put forth by the NBB.
3.4. Evaluation & Regulatory Processes
National Biosafety Board and Genetic Modification Advisory Committee
The National Biosafety Board (NBB) and Genetic Modification Advisory
Committee (GMAC) were established in May 2010 under the Biosafety Act 2007 by
the Ministry of Natural Resources and Environment Malaysia (NRE). One of the
areas under the NBB's purview is responsibility for decisions pertaining to the
release, importation, exportation and contained use of any living modified
organism (LMO) derived from modern biotechnology. The GMAC, on the other hand,
is responsible for providing scientific, technical and related advice to the
NRE and the NBB.
Approval Process
Application for approval is completed by the applicant and submitted to
the Director-General (DG) of NBB together with the prescribed fees, risk
assessment and a risk management report, emergency response plan and any other
information as may be specified by the NBB.
Upon receipt of the application, the DG refers it to the GMAC and
relevant government agencies for their recommendations and invites public
participation for the purpose of public disclosure.
The GMAC recommends whether the application should be approved and the
terms and conditions to be imposed by the NBB.
After giving due consideration to the GMAC's recommendations, comments
of the relevant agencies, views of the public; if any, and any additional
information, the NBB then determines whether or not a certificate of approval
will be granted.
For further information on the NBB, GMAC or the approval process, visit
http://www.biosafety.nre.gov.my
Public Engagement Exercise
The following activities were carried out by IMR and MNRE to inform the
public before the MRR trial in Bentong:
A public announcement was issued by MNRE in Berita Harian and New Strait
Times on August 5th and 19th 2010. The public announcement message was also
simultaneously uploaded onto the Biosafety Department's website
(www.biosafety.nre.gov.my).
Due to low turnout of response from the public, the Biosafety Department
invited nine Non-Governmental Organizations to provide their comments/response
on August 23rd 2010. They were given 30 days to provide their feedback.
The issues raised by the NGOs were analysed and the feedback was
published in the Biosafety Department website.
A Question & Answer session with the media was
organized by the MNRE on October 29th 2010.
21 members of the media registered at this event. The session was chaired
by Mr. Letchumanan Ramatha, Director General of the Biosafety Department of
MNRE. Other resource people present were Dr. Ahmad Parveez Hj. Ghulam Kadir
(Chair of the Genetic Modification Advisory Committee), Prof. Helen Nair,
Assoc. Prof. Dr. Mohd Faiz Foong Abdullah and Dr. Tan Swee Lian (Members of the
Committee).
Besides engaging the public at large through media public announcement
and public consultation, IMR has also conducted the following briefings or meet
the people in Bentong, Pahang. The following sessions were organized:
Briefing to the Bentong Municipal Council members – a briefing was
carried out to the members of the Council, chaired by Tuan Jamiri Haji Sainan,
Evaluation Officer of the Majlis Perbandaran Bentong on November 1st 2010. The
briefing session was attended by IMR and Oxitec representatives and Bentong's
Municipal staffs. Dr. Lee Han Lim gave a background presentation on the
transgenic Aedes aegypti project and terms & conditions of
the approval from the National Biosafety Board. There was a hands-on demonstration
of the inability of male mosquitoes to bite, both wild type and transgenic
strains. Representatives from Bentong Municipal Council stressed that they
supported the project. However, they proposed that all of the stakeholders in
Bentong (Bentong Health Office, Bentong District and Land Office and Bentong
Police Department) should be invited to meet and discuss the implementation of
the project. IMR was asked to find out the ownership of the proposed trial site
from the Bentong District and Land Office.
A second briefing was conducted in Majlis Perbandaran Bentong on
November 10th 2010, chaired by Tuan Zainal Abidin Bin Md Amin, Secretary of the
Majlis Perbandaran Bentong in presence of other government departments
including Bentong Health Office and Bentong Land & District Office. All
stakeholders and chairman agreed to give their cooperation to IMR by giving all
the necessary support letters in order to fulfil the terms and conditions
required by NBB. Dr. Lee and Dr. Vasan informed all stakeholders that the exact
spot(s) where the transgenic mosquito would be released was located in a
government land. IMR requested for approval from the Bentong Municipal. The
Chairman agreed and the support letter was faxed to IMR. In addition, since
some mosquito traps (BG-Sentinel and ovitrap) were to be placed in a private
land adjacent to the trial location, IMR also provided the written consent from
the land owner.
Briefing to the Independent Monitor (Akademi Sains Malaysia
representative, Dato' Prof. Dr. C.P. Ramachandran) by Dr. Lee and Dr. Vasan was
carried out on November 16th 2010.
Based on the NRE guidelines, IMR was requested to display posters
announcing the trial in the uninhabited trial sites at least 2 weeks before the
beginning of the trial. They were placed on November 30th 2010, 22 days before
the release.
The position of the posters were inspected and validated by the NRE
representatives, Mr. Onn B. Mohd Jadi and Mr. Mohamad B. Omar, on December 1st
2010.
Briefing to Pahang State Exco Members chaired by the Chief Minister was
carried out on December 1st 2010.
A Public briefing on the Limited Mark-Release-Recapture Experiment in
uninhabited area in Bentong Pahang was conducted on December 9th 2010. The
briefing was carried out in two sessions. The first session was conducted in
Bentong Municipal Council Hall in Bahasa Malaysia and English languages while
the second session was conducted in Dewan Perhimpunan Cina (Chinese Town Hall,
Bentong) in Mandarin.
3.5. The Team
Oxitec
Oxitec Limited was founded in 2002 to develop and commercialise
leading-edged science and biotechnology developed at the University of Oxford,
United Kingdom. Oxitec has built a broad portfolio of patented technology as
well as world-leading expertise in insect molecular biology and regulatory
affairs.
In 2010, Oxitec Malaysia Sdn Bhd was established, demonstrating the
Company's commitment to helping Malaysia in her dengue control efforts.
Oxitec's approach to insect control via the development of genetic
strategies to control disease-carrying mosquitoes has been recognised by
leading academics and institutions worldwide. The Company has also received
grants from the UK Government to facilitate research and development and is
working with the WHO on a project to develop best practices in the deployment
of genetic control methods against mosquito disease vectors in disease endemic
countries.
For further information on Oxitec, visit http://www.oxitec.com
Institute for Medical Research
The Institute for Medical Research (IMR) began in 1900 with a
recommendation from Sir Frank Athelstane Swettenham, Resident–General of the
then-Federated Malay States, to establish a Pathological Institute in Malaya to
'carry out scientific and sustained research into the causes, treatment and
prevention of such scourges as beri-beri and all forms of malaria fevers.'
In 2001, the IMR restructured into six research and two support centres.
Within each of these, scientists from various disciplines collaborate with IMR
researchers on priority research projects. This approach and the consolidation
of resources have enabled the IMR to venture into growth areas and bring
research closer to the cutting edge of science and technology.
For further information on IMR, visit http://www.imr.gov.my/index.php
4. TOP 12 FAQs
1. Why did the Government give its approval for
this experiment?
The Aedes aegypti mosquito is the main carrier of
dengue, for which there is currently no effective vaccine or specific
treatment. The only way to stop dengue is to control the mosquito. As existing
control technologies seem unable to stop the spread of dengue and chikungunya,
there is an urgent need to evaluate new control technologies.
2. How does the experiment work?
The male Aedes aegypti (OX513A) mosquito strain that
was released has a self-limiting genetic element. When female Aedes
aegypti mate with the OX513A male mosquitoes, any offspring will die,
hence preventing the emergence of the next generation of adult mosquitoes. The
released sterile male itself will also die. The strain also contains a
fluorescent molecular marker which glows under specific light wavelengths to
aid identification between the OX513A and wild Aedes aegyptimosquitoes
in the field in the monitoring of trial results.
3. Will this limited release experiment reduce the
mosquito population?
No, because the number of sterile male mosquitoes to be released is too
small. This will be a first step for larger-scale experiments that may be
carried out in future, subject to approvals from the relevant authorities.
4. What if I am bitten by an OX513A mosquito?
Only male Aedes aegypti mosquitoes will be released and
male mosquitoes cannot bite. Aedes aegypti mosquitoes also
CANNOT mate with any other types of mosquitoes or with any other
organisms. It should be noted that this experiment will NOT control wild
female mosquitoes that are already in the area. Therefore, if by chance you are
bitten by a WILD FEMALE mosquito, treat the bite like you normally would and,
if you feel any symptoms such as headache, joint pain, nausea and fever, then
immediately consult a doctor for further treatment.
5. You say only sterile male mosquitoes will be
released. How can you be so sure? What if a female mosquito is released
accidentally?
Great care is taken in the sorting out of the male from the female pupae
in the laboratory. It is possible for an experienced person to sort the male
pupae from the female as the males are smaller and they have different
characteristics. Quality control checks are also carried out in several stages
to reduce the possibility of females being included. If however, small numbers
of females are released, they will die. Even if they potentially mate, the
offspring will die as larvae.
6. What happens once the sterile male mosquitoes are released?
The Aedes aegypti is a relatively short-living
mosquito. Adult males can live around 10 days or so in the environment. In the
laboratory, under ideal conditions, they can live a bit longer and in extreme
cases, up to a month. Once the sterile male mosquitoes have mated with the wild
female Aedes aegypti, any offspring will die. The average time the
released males lived in this experiment was between 2-3 days.
7. Should we be doing anything different while the
experiment is taking place eg. stay indoors, etc?
You should go about your lives as normal. The experiment is only taking
place for two days, with four releases (one in the morning and one at night) in
total and this process will not interrupt your daily routine.
We however, seek your cooperation with the IMR’s field officers to allow
them to place the ovitraps or adult traps and to collect them from your
premises.
8. Can we still use insecticide (Ridsect) during
the trial period?
You can if you want to. However, we prefer if no insecticide is used
during the trial period as this will allow us to obtain a more accurate
statistics on the reduction of theAedes aegypti mosquito
population.
9. Was the mark-release-recapture trial the first of its kind in the world?
No. The Cayman Islands Mosquito Research and Control Unit has successfully used this technology in open field trials since 2009 and similar (open field) trials are ongoing in Brazil.
The US Department of Agriculture has also been conducting open field trials of a living modified strain for the Pink Bollworm (Pectinophora gossypiella), a moth that is a pest of cotton, since 2006. In 2008, over 15 million modified moths were released aerially in one experiment. These trials and the living modified moths performed exactly as predicted and no negative outcomes of any type (whether environmental, agricultural or to human health) were observed.
10. How was the site for the first test selected? Does this mean the locations chosen are breeding grounds for Aedes aegypti?
The IMR has been carrying out fieldwork at a number of places to study
and collect the necessary data and to carefully evaluate potential sites for
open field trials. The defined criteria; such as scientific, regulatory, social
and ethical, have to be taken into consideration before a site is selected. The
criteria include:
i.
Presence of Aedes
aegypti mosquitoes
ii.
A stable
population of Aedes aegypti mosquitoes
iii.
Size of the
trial site can demonstrate the accuracy of the trial results
iv.
An isolated
site that reduces the possibility of incoming Aedes aegypti mosquitoes from
surrounding areas
v.
Logistics ie,
not too far from the IMR laboratory in Kuala Lumpur
11. What are the likely impacts on the environment
and humans when releasing GM mosquitoes?
Aedes aegypti is not
a native insect to Malaysia and only achieved pan-tropical distribution in the
1930s. It is an urban and semi-urban mosquito which prefers to live around
humans. As there are no birds, fish or other insects that feed exclusively on
it and there are other mosquito species they can eat, reducing the number of Aedes
aegypti is not likely to have any impact on the environment.
Additionally, the released mosquitoes will die in the environment and their
progeny will die so this is a 'self-limiting' approach ie, there is no
permanent change to the wild mosquito population.
The main impact will be to reduce the number of Aedes aegypti females
that bite and spread disease. There is no threat to humans as the mosquitoes
that are released are all males and males do not bite or spread disease.
12. How do we know if our homes are breeding grounds or not and how can we stop this?
Aedes aegypti breed
in clear, stagnant water in containers – not dirty water in drains (longkang),
river, stream, etc. – and they breed both outdoors and indoors. You can help
control Aedes aegypti by removing their breeding sites by:
i.
Checking roof
gutters and apron drains for blockages regularly
ii.
Removing
water from pot plant plates
iii.
Keeping toys
and canvas sheets under shelter
iv.
Changing the
water in vases regularly and scrubbing the insides of the vases
before refilling with fresh water
v.
Fitting gully
traps with anti-mosquito valves
If everyone plays their role in helping wipe out the places where Aedes
aegypti mosquitoes breed, this, combined with Integrated Vector
Management, will go some way towards helping control the spread of dengue in
Malaysia.
Info : http://www.imr.gov.my/
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