Introduction
There are a lot of entities that might have been the cause of a lot of deaths in the past years and it is the researchers and the scientists’ responsibility to determine what entities might have caused it. One entity that might have caused the deaths of these people is different diseases that are most likely transmitted via an insect or any other host (MLER, 2011). There are already a lot of issues that researchers and experts are discussing about this particular microbe. To better understand this paper, a brief overview about Wolbachia and vector borne diseases is necessary.
Wolbachia is a bacterium that could also act as a parasite. Actually, it is amongst the world’s most common microbes that are also considered as parasites. The interesting thing about Wolbachia is the fact that it can affect and infest mosquitoes and affect them in an unusual way. It’s a wonder how these microbes can still manage to survive the harsh environment inside the body, defended by the insects’ first line of defense against foreign bodies. These parasitic microbes could easily be transmitted into an insects system because a lot of other insect species can actually carry these microbes.
There is a great issue that becomes a common product and source of debates these days and it has basically two components. One is the microbe Wolbachia and the second is the occurrence of vector borne diseases. We are going to figure out if there are direct or indirect relationships between Wolbachia, a microbe, and the transmission of different diseases, particularly the ones that could result from Wolbachia infestation.
Wolbachia to Reduce Transmission of Mosquito Borne Diseases
It’s still remains a question for many whether Wolbachia could really play a significant role in reducing the transmission rates of different mosquito and insect induced diseases. Is it impossible? Or is it possible, only that it has a lot of gaps? According to a study conducted by Hancock, Sinkins, & Godfray (2011), there is a great possibility that certain strains of Wolbachia could have the potential of lowering the vectorial capacities of mosquitoes, regardless of gender and specie, to transmit different diseases.
The fact that mosquitoes are one of the most common causes of transmission of deadly diseases around the world is part of our common knowledge already (WHO, 2011). In their research, they used different models to determine what gender bias would be more applicable in providing the results that they wanted.
Basically, the aim of the research was to identify what type of gender bias model could be more important in decreasing the possibility of further spread of mosquito-transmitted diseases in the future. They basically tried different strategies. First, they tried to favor a population of female mosquitos. After getting the results, they then tried doing the same set of procedures to a population of male mosquitos and so on and so forth. This is actually called a sex-structured model of Wolbachia-mosquito interactions.
The results of their study showed that male-biased releases are more effective and safer in the establishment of the symbiont in mosquito populations. The significance is that this research could be a major stepping stone and could even be considered a breakthrough for other researchers to devise out more accurate strategies in preventing the spread of vector-borne diseases (Osborne, Leong, O’Neill, & Johnson, 2009)—these diseases have already caused our society a lot of deaths and it is imperative that researchers and experts find something significant about lowering the incidence cases soon.
If we are going to base on the results of this particular research, we could easily say that by introducing Wolbachia into mosquito populations, in a couple of years or so, the rate of transmission of different mosquito borne diseases such as malaria and dengue would have been reduced already. As of now, the normal process of introducing Wolbachia into mosquito populations is by release of equal numbers of male and female mosquitoes with Wolbachia. At some point, the number of female mosquitoes that will be released would have to be decreased because they are (in most species) the ones responsible for nuisance biting. Regarding the type of gender bias to be facilitated, it would be more appropriate to analyze the different types of mosquito species first so that it could be easily known whether a male-bias release could be more effective than others or not.
Another research about the possible results of Wolbachia introduction to mosquitoes was conducted by a group of researchers from the American Society of Microbiology. According to such research, Wolbachia research offers a wider field to be researched by future researchers (Tamarozzi et al., 2011).
They found out that introduction of Wolbachia in species containing different pathogens could be a wise decision to make once the reputation of Wolbachia in decreasing rates of malaria and dengue cases is already established. Onchocerciasis is one of the most common causes of blindness and is also caused by a parasite. If we are to use the same principle (introduction of Wolbachia to the involved parasite transmitting population), there could be a great chance that the incidence rates of Onchocerciasis would be decreased as well. This is one of the progressions that could be made once it’s already proven that Wolbachia plays an important role in the life cycle of mosquitoes, as if it means life and death to them (Fenn et al., 2006). Wolbachia after all causes the parasites present in the mosquitoes to be killed or the mosquitoes themselves to have a significantly shorter lifespan.
As an addition to the evidences that were gathered, Walker and O’Neill’s research (2011) was also of significant importance. It is important not only in terms of proving the effectiveness of Wolbachia in decreasing rates of vector-borne and mosquito-induced diseases.
Wolbachia Transfer into Mosquito Populations
This is one of the most common ways of controlling spread of diseases brought about by different mosquito species. Particular mosquito specie that was targeted in the study was the Aegis Aegypti. Generally, its behaviors are the same with other mosquitoes only that it carries a parasite that could cause a serious illness once it already bitten a human. Embryonic microinjection is the one that is usually done in using this method but it would be important to know that mosquitoes could still be naturally infected by Wolbachia.
Relative Merits of using Wolbachia to control Vector-borne diseases
It is clear that by exposing mosquitoes to Wolbachia and having them infected by the said bacteria, certain changes in their body, particularly in their sex organs could take place. All in all, such would usually result to a shorter life span for the host insect. If the insect has a shorter lifespan, then the probability that it would be able to transmit the pathogen present inside its body to an animal or worse to a human being would be significantly decreased. This is probably the biggest merit that our society could get from using Wolbachia as an intervention.
Conclusion
In summary, it could be inferred, based on the evidences gathered that mosquitoes and their harmful effects could be dramatically reduced once Wolbachia, a bacteria, is introduced to their population. Also, there is a great possibility that mosquito-borne diseases will not be the only ones that could be targeted. Other vector-borne diseases could also be targeted provided that Wolbachia could carry on the same effects that it did to the mosquitoes, based on the researches critically reviewed. Furthermore, there are a lot of possible methods we could conduct to introduce Wolbachia to different insects but the most usual method of transfer appears to be the use of embryonic microinjection.
References
MLER. (2011). Wolbachia Collection. MLER. Accessed January 2011. Available at http://serc.carleton.edu/microbelife/topics/wolbachia/resources.html.
Hancock, Sinkins, & Godfray. (2011). Strategies for introducing Wolbachia to Reduce Transmission and Mosquito-Borne Diseases. PLOS Negl Trop Dis. Print.
WHO. (2011). Vector-Borne Disease. HELI. Accessed January 2011. Available at http://www.who.int/heli/risks/vectors/vector/en/index.html.
Osborne, Leong, O’Neill, & Johnson. (2009). Variation in Antiviral Protection Mediated by Different Wolbachia Strains in Drosophilia Simulans. PLOS Pathog 5. Print.
Tamarozzi, F., Halliday, A., Gentil, K., Hoerauf, Pearlman, E., & Taylor, M. (2011). Onchocerciasis: The Role of Wolbachia Bacterial Endosymbionts in Parasite Biology, Disease Pathogenesis and Treatment. Clinical Microbiology Reviews. Print.
Fenn, K., Conlon, C., Jones, M., Quail, MA., Holroyd, NE., Parkhill, J., & Blaxter, M. (2006). Phylogenic Relationships of the Wolbachia of Nematodes and Arthropods. PLOS Pathog. Print.
Walker, T., & O’Neill, S. (2011). Wolbachia and the Biological Control of Mosquito-Borned Disease. Victoria, Australia: Embo Reports. Print.
