Last modified on 2 February 2012, at 10:09

Lentis/Malaria and Mosquito Nets

Each year there are 247 million cases of malaria globally, 881,000 of which result in death. Preventive measures currently exist to protect the approximately 3.3 billion people at risk in malaria-endemic areas.[1] In the absence of an approved malaria vaccine, the most widespread preventative measures are insecticide treated nets (ITNs) and indoor residual spraying (IRS). Recent anti-malaria efforts are centered on the distribution and effective use of ITNs because of the cost-effectiveness of the nets and their potential to reduce childhood mortality rates by 20%.[2]


Mosquito Net TechnologyEdit

The use of ITNs in malaria prevention started in World War II.[3] These early nets, however, were not adequately safe for human use. It was not until the 1980s, when safer photostable synthetic pyrethroids were used, that mosquito nets became a well-known malaria prevention method.[3] According to the World Health Organization, natural fibers such as cotton and artificial polymers such as nylon and polyester are options in the construction of ITNs.[4] The construction material of choice is then dipped in a solution of insecticide whose concentration is dependent on the adsorbing material.[4] Long-lasting insecticide nets are another measure designed to prevent malaria. They offer four to five years of protection when treated with Deltamethrin, a pesticide approved by the World Health Organization for use on mosquito nets and walls.[5] [6] The insecticide is embedded within the bulk of this specific mosquito net and releases over time. [7]

Distribution of NetsEdit

Over the past decade the global community has debated over whether aid organizations should distribute ITNs on a basis of equity or sustainability. Under the strategy of equitable distribution, organizations provide ITNs to all populations in malaria-endemic areas.[8] This requires significant funding from organizations such as the Global Fund to Fight AIDS, Turberculosis, and Malaria; UNICEF; and the World Bank.[9] The goal of the Roll Back Malaria Strategic Plan is to implement ITNs in 80% of the population at-risk for malaria.[10] This requires an estimated $1.9 billion per year, which is more than the current level of international investment in the fight against malaria. As an alternative approach, the strategy of sustainable distribution addresses concerns that funding for ITNs may wane and that public sector resources may strain in years to come. To encourage sustainable preventative measures against malaria, this strategy calls for commercial market development of ITNs.[8]


Social MarketingEdit

Social marketing is based on the concept that the poor value purchased brand-name goods more than freely distributed goods. This is the basis for aid distribution of contraceptives and oral rehydration therapy.[11]

Public and Private Sector CooperationEdit

The Academy for Education Development (AED), which is now part of the global development organization FHI360, and the US Agency for International Development (USAID) joined together to initiate the NetMark Project. The project aimed to create sustainable commercial markets for ITNs in seven African countries. Between 2002 and 2009 the AED sold over 60 million ITNs under the NetMark Project. They offered vouchers, which discounted nets from 40 to 100 percent, to 2.1 million families who could not afford the full price of ITNs. AED is no longer funding the project but remains tied to commercial distribution partners in the seven countries.[12]

Commercial SectorEdit

Vestergaard Frandsen, a company which specializes in disease control textiles, is a proponent for social marketing of ITNs. They offer the same net under two different names. Antenatal clinics distributed the Mama SafeNite net at a subsidized price while commercial outlets distributed the Permanet net at higher costs. The company hopes that Mama SafeNite will be accessible to vulnerable groups while Permanet will create demand for ITNs and lead to a sustainable market for the product.[13]

Sociotechnical InterfaceEdit

The debate between public vs. private sector health initiatives is analogous to policy issues in the agricultural development sector. In particular, the distribution of nets resembles the supply of food aid. There must be a balance between the rapid approach to distribution and sustainable development. Some groups believe that the public sector should provide ITNs for the masses. Another approach to distribution is to provide nets at low or no cost to the most vulnerable populations while simultaneously encouraging growth of the commercial ITN sector.[8] Recent reports show that most organizations are phasing out the social marketing strategy and increasing the relative percentage of freely distributed nets.[14]

Barriers to Effective Net UseEdit

Although mosquito nets can significantly reduce the prevalence of malaria, there are many variables that deter effective net use. These include environmental, technical, and social barriers.

Lack of UseEdit

One factor that leads to a lack of use of mosquito nets is individuals not possessing the nets or not possessing enough nets. A study by Vanden Eng et al., showed that in Madagascar, 75.2% of the persons living in households with ITNs hanging, but who did not sleep under an ITN, replied "either someone else was using the net or there were not enough nets available." [15]

Another factor that affects net use is the structure of sleeping arrangements inside the home. According to the malaria journal, the most suitable location for hanging nets is in bedrooms. However, non-living room areas are also used as sleeping quarters and users are more likely to take down nets during the day in non-bedroom locations to increase space for various daily activities. [16] Another reason for lack of use of mosquito nets is the stability of sleeping sites.[16] Depending on the daily activities, individuals must shift their non-bed sleeping sites to different areas of the living room. Moving the mosquito nets is seen as a hassle and this reduces the use of such nets. Another technical reason for non-use of mosquito nets is that many houses lack the infrastructure to hang mosquito nets. Most homes in Sub-Saharan Africa are not made of brick and it is difficult to secure the nets the ceiling of houses.


Mosquito nets exacerbate the already hot climate of the Sub-Saharan region because they reduce air flow. People feel uncomfortable and hot when trying to sleep under these nets. A Malaria Journal study found that discomfort, primarily due to heat, was one of the major reasons why people did not use mosquito nets. [17] The perceived discomfort from sleeping under the net led individuals not to use it. Another primary reason for not using mosquito nets was a low perceived risk of malaria or a low perceived mosquito density in the surrounding area.[17] Studies from medical anthropologists show that rural African villagers view malaria as a common aliment similar to how western culture views the flu. [18]


"Misuse"Edit

Many people misinterpret mosquito net misuse. When there is an excess of nets in a particular community, that community will often use the the nets for different purposes. This is not so much misuse as it is a novel way to utilize a surplus of resources. Villagers use nets for a variety of tasks including ant traps, bridal veils, and fishing nets.


Sociotechnical InterfaceEdit

Mosquito nets are technical artifacts. However, social factors govern their use and possible misuse. As seen above, the individual decides how to best use the technology. Non-technical factors such as discomfort due to heat and a perceived low mosquito density are factors that limit the use of mosquito nets. [19] Both technical and social factors are involved in the use of mosquito nets and the prevention of malaria. [20]

ConsiderationsEdit

Different methods exist to prevent the spread of malaria. A mosquito net is one such technology that the health community implements in this effort. However, the promotion of malaria prevention innovations may have unintended consequences. Psychology Professor Gerald Wilde of the Queen's University in Canada hypothesizes that people "will adjust their behavior in an attempt to eliminate any discrepancies" between their perceived risk and their "target level of risk," which is defined as the level of risk an indivudal is willing to accept. [21] This theory essentially explains that a person will take on more risk if the risk associated with an action is perceived to be lower than it actually is. This hypothesis applies to the use of anti-malaria mosquito nets. The perceived risk associated with contracting malaria should be high, but the above explanations show that it is in fact low for many people. Those susceptible to malaria should take every precaution to avoid the high risk, and follow the guidelines provided through the promotion of ITNs and LLINs. According to Wilde's theory, the institution of mosquito nets would eventually lead to the people raising the amount of risk they are willing to take. Any preventative technology must take into account this possibility of users reverting back to their old mindset of low perceived risk. Susceptible groups eventually come to an equilibrium, or "homeostasis", by lowering their perceived malaria risk to levels before the institution of mosquito nets.[21]

As previously mentioned, multiple avenues exist to combat the prevalence of malaria in Africa and other regions. Rather than rely on social groups such as charities or government institutions to enforce the use of malaria prevention technology, the people directly fighting the disease should be the primary innovators and enforcers. This solution is embodied in an economic theorem named the endogenous growth theory. It states that a nation's economic growth is a result of "internal processes" and increases through investment in human capital. In particular, growth is caused by new forms of technology developed from within the culture.[22] Application of this theory to malaria prevention depends on local people to develop prevention technologies. This method could eliminate the barrier between the experts and the affected population and actually increase the willingness to overcome barriers to use.

ReferencesEdit

  1. Roll Back Malaria. Key Malaria Facts. http://www.rollbackmalaria.org/keyfacts.html
  2. Centers for Disease Control and Prevention. Insecticide-Treated Bed Nets. http://www.cdc.gov/malaria/malaria_worldwide/reduction/itn.html
  3. a b Ehiri, J. E., Anyanwu, E. C., & Scarlett, H. (2004). Mass use of insecticide-treated bednets in malaria endemic poor countries: public health concerns and remedies. Journal of Public Health Policy, 9-22.
  4. a b World Health Organization. (1995). Annex VII: Procedure for Treating Mosquito Nets and curtains. Retrieved from Regional Guidelines on Dengue/DHF Prevention and Control: http://searo.who.int/en/Section10/Section332/Section554_2554.htm
  5. International Traveler's Clinic. (2011). Long-lasting mosquito net. Retrieved from Travel Health Help: http://www.travelhealthhelp.com/nets7.html
  6. Tenenbaum, D. J. (2005). A Safe Mosquito Net Treatment? Minimizing Deltamethrin Risks to Children. Environmental Health Perspectives, A402.
  7. Khandal, R. K., Tyagi, A., Sharma, T., Singh, M., Fatma, K., Rawat, V. S., et al. (2010). Studies on Deltamethrin Treated Mosquito Net. E-Journal of Chemistry.
  8. a b c Hill, J., Lines, J., & Rowland, M. (2006). Insecticide-treated nets. Advances in Parasitology, 61, 77-128. doi: 10.1016/S0065-308X(05)61003-2.
  9. UNICEF. (2011). Malaria. www.unicef.org/health
  10. Roll Back Malaria. (2005). Global Strategic Plan 2005-2015. http://www.rollbackmalaria.org/forumV/docs/gsp_en.pdf
  11. Kyama, R. & McNeil, Jr., D.G. (2007, October 9). Distribution of nets splits malaria fighters. The New York Times. http://www.nytimes.com/2007/10/09/health/09nets.html
  12. AED Center for Private Sector Health Initiatives. (2011). Malaria fact sheet. http://pshi.fhi360.org//pdfs/Malaria_NM_Dec2010.pdf
  13. Vestergaard Frandsen, M. Sociatl Markting of ITNS. http://www.docstoc.com/docs/21368144/Social-Marketing-of-ITNs
  14. Kyama, R. & McNeil, Jr., D.G. (2007, October 9). Distribution of nets splits malaria fighters. The New York Times. http://www.nytimes.com/2007/10/09/health/09nets.html
  15. Vanden Eng et al. Malaria Journal 2010, 9:133 http://www.malariajournal.com/content/9/1/133
  16. a b Sleeping arrangement and house structure affect bed net use in villages along Lake Victoria. Malaria Journal. 2010; 9: 176. http://www.malariajournal.com/content/9/1/176
  17. a b Pulford J, Hetzel MW, Bryant M, Siba PM, Mueller I: Reported reasons for not using a mosquito net when one is available: a review of the published literature. Malar J 10:83. http://www.malariajournal.com/content/10/1/83
  18. Shan,Sonia. In Africa, anti-malaria mosquito nets go unused by recipients.May 2 2010 http://soniashah.com/articles-by-sonia-shah/in-africa-anti-malaria-mosquito-nets-go-unused-by-recipients/
  19. Pulford, J; Hetzel, M.W.; Bryant, M; Siba, P.M.; Mueller, I. Reported reasons for not using a mosquito net when one is available: a review of the published literature. http://www.malariajournal.com/content/10/1/83
  20. Abdella Y.M, Deribew A, Kassahun W: Does insecticide treated mosquito nets (ITNs) prevent clinical malaria in children aged between 6 and 59 months under program setting? J Community Health 2009, 34:102–112.
  21. a b Wilde, G. J. (1998). Risk Homeostasis Theory: An Overview. Inj Prev, 89-91.
  22. Investopedia. (2011). Endogenous Growth Theory. Retrieved from Investopedia: http://www.investopedia.com/terms/e/endogenousgrowththeory.asp#axzz1fPGpfitP