Open Access

Roles and challenges of construction firms and public health entomologists in ending indoor malaria transmission in African setting

Malaria Journal201615:554

https://doi.org/10.1186/s12936-016-1607-9

Received: 13 July 2016

Accepted: 8 November 2016

Published: 14 November 2016

Abstract

Indoor malaria transmission reduction across sub-Saharan Africa has been attained through implementation of long-lasting insecticidal nets and indoor residual spray interventions with small-scale larval source management. Improvement of house structures in sub-Saharan Africa can lead to zero indoor malaria transmission with evidence from West Africa, East Africa and Middle East countries. Residual malaria transmission cannot be targeted well with LLINs and IRS alone, but with incorporation of house structures modifications it may be possible.

Keywords

Malaria Indoor transmission House modification Entomologists Construction firms

Background

In recent past, malaria control has been successful for reduction of mortality and morbidity related cases upto 438,000 malaria deaths (range 236,000–635,000) worldwide per annum [1], which is a decrease of malaria mortality cases by 60% since 2000 [2]. The main routes which so far have played a major role in reduction of the observed malaria mortality and morbidity includes (1) proper diagnosis and the use of appropriate anti-malarial drugs; (2) the use of adult vector control tools such as indoor residual spray (IRS) and long-lasting insecticidal nets (LLINs); and (3) larval source management in some rural and urban areas [1]. For past two decades, insecticide resistant among malaria vectors has been reported for different classes of insecticides used for vector control [3]. Eighty percent of malaria cases have been found to be transmitted indoors in sub Saharan Africa [4]. The use of LLINs and IRS indoors has reduced but not limited the vector house entry and feeding behaviour which has cause to have a substantive changes in vector composition in many areas with Anopheles gambiae s.s. all but disappearing, leaving Anopheles arabiensis, which is known to be capable of feeding extensively on humans early in the evenings, before human go indoors, as the only remaining vector species of the An gambiae s.l. complex [4]. The use of LLINs and IRS indoors has reduced vectors house entry behaviour and caused species shifts due to indoor insecticidal pressure [5, 6], shifts to early-evening or early-morning biting [7]; shifts to exophagy [6, 8]; shifts to zoophily [9] and shifts to exophily [10]. More efforts are needed to address restriction of vector house entry behaviour and zero indoor malaria transmission. This commentary work put more emphasis on the way African house improvements could lead to the indoor vector abundance reduction and zero indoor malaria transmission and restrict to have the malaria foci.

The main routes for mosquito house entry are eaves, open window and doors [1116]. The traditional African houses are short and have eaves, unscreened doors windows [17]. The short walls of the houses have enhanced mosquito to enter the house easily at the height of 2–2.5 m; windows are mostly located at the height 1–1.5 m above the earth surface. The behavioural response of mosquitoes to human or other host odour indoors has found that, mosquitoes to have ability of going through windows, open doors and eaves [18]. The house structure have changed in terms of height, sealed caves and with screened windows and door [12]. These changes have found the indoor vector density declining [12]. In other sites, malaria incidences found decreasing among household members with reference to house type, entry points blocking (windows and doors screening, and eaves blocking) [14, 19]. In Western Kenya, introduction of house sealing using locally available cheap resources found the indoor house vector density decreased and subsequently malaria reduction [20]. In the Sao tomé, Charlwood and others realized that, increasing the house height upholds vectors opportunity to enter the houses [21]. In the other trial conducted in West Africa by Njie and others found that, screening the houses most entry points eaves, doors and windows lead to reduced density of An. gambiae s. l. in doors but not for Culicine species [13]. Reduction of Anopheline house entry directly reduces the risk of indoor malaria transmission.

The major role to be played by the construction industry (private–public sector collaboration) and public health entomology include capacity building to human resource available in the firms already practicing construction on mosquitoes house entry control by house structure modifications which includes, house walls height increase, eaves sealing, and house window and door screening. Capacity building by introduction of modules for public health entomologists and structural engineering in colleges for adapting training curriculum to changing epidemiological and entomological determinants, more implementation or operational research.

Public health entomologists, who are part of National Malaria Control Programmes (NMCP’s) across sub-Saharan Africa, have to play the role of educating the community on vector behaviour and house entry points. The shortage of public health entomologists in sub-Saharan African might be a problem to reach the rural community [22], but the effect of house construction for vector control could be vivid when engineers and all construction firms will be fully integrated in public health. Integration of public health entomologists and engineering firms can give better solution in vectors house entry control with use of existing evidences [11, 21]. Public health and field entomologists have declared that the IRS and LLIN lost efficacy against mosquitoes due to the insecticide resistance developed in some vectors [23]. The most reliable method for the fight against indoor vector density control could only be modification of the house structures (e.g., by sealing of eaves, screening of doors and windows). This could be the best supplement of larval source reduction, IRS and LLINs coverage. The larval source reduction in combination with IRS and LLINs have been great in vector and disease transmission reduction [24], but still there is residual malaria transmission in several part of Africa [25].

In Africa, the major challenges expected towards house modification for malaria control are traditions (for some tribes on house style) socio-economic status [26] and settlement problem for nomadic communities [27] and refugees. In Africa, some nomadic tribes are still hold on to their traditions which include none permanent low quality house style and poor access to health system [28]. These are among tribes that do not change their traditional life style easily and hence challenges to houses improvement still need more effort. These challenges can be resolved with the use of traditional leaders of each community who can champion the house style improvements in their communities in collaboration with public health entomologists. Traditional leaders are used as informers and changers in community in Africa [29]. Social economic status of African rural communities still a challenge on attaining better health and live hood, mostly in house infrastructure [30]. The main source of income in rural areas of Africa is agriculture which depends on natural rain cycles with small scale irrigation [30]. Unreliable rains have reduced harvests and subsequently family income due to climate changes and unpredicted climate changes [31]. The outcomes of low-income has been observed and indicated by the extreme poverty. The improvement of houses for malaria control shall be hindered on this circumstance of poverty. Nomadic communities have no settled home, move from place to place for fruit gathering, hunting, finding pasture for livestock, or otherwise making a living [32]. These communities have not permanent house structures as they migrate from time to time to meet their daily needs. More efforts are needed to motivate this community for permanent settlements by government and political leaders of their communities. Refugees in sub-Saharan Africa are the products of internal political conflict in different countries, such as Eritrea and southern Sudan, which makes Ethiopia a most refugee hub of Africa [33] followed by Kakuma camps in Kenya [33]. These camps have been having high malaria incidences due to poor sheltering and health services [34]. These camps are temporary for humanitarian basis and have to complement the standard practices for malaria control in humanitarian emergencies to increase indoor infectious mosquito bites protection and supplement protective gears for outdoor protections such as repellents [35]. More efforts to avoid having malaria foci for stabilizing political status in African countries are needed with the management of residual malaria transmission. Deployments of tools such as insecticide-treated plastic sheeting and treated blankets [36], Zero Fly [37], non-mesh LLINs products [38] and use of repellents both synthetic and plant based [39] for malaria control in conflict and emergency humanitarian situations. Government and private firms should ensure to promote these tools in terms of safety, acceptability and their availability upon demand. Strategise on purchase and distribution to enhance manufacturer confidence for production to meet the community demand. The use of non-pyrethroid compounds should be also promoted to manage the growing pyrethroid resistance such as non-pyrethroid treated wall lining materials [40].

What is the way forward?

Malaria control in sub-Saharan Africa should be taken as a multi-sectorial effort to maintain and exceed attained control efforts [41]. There should be a policy in place for integrating construction firms and NMCP’s programmes in Africa for designing better houses that bring indoor malaria transmission to zero. Refugees and nomadic life styles should be discouraged by head of African states with alternatives sources of better income for permanent settlements. Majority (80%) of the African population in rural areas rely on rain based agriculture for food and cash crop productions [42]. Climate change has lead to reduced and unreliable rains, hence governments should address better infrastructure for irrigation to enhance better family income, housing and increased social economic status (improved livelihood).

Conclusions

This commentary demonstrates that collaboration between public and private sectors under the national malaria control programmes to assess options for addressing residual transmission can have measurable outputs. This can be achieved under programmatic conditions through pilot studies with strong monitoring, evaluation and operational research components, similar to what has been done by the Onchocerciasis Control Programme in West Africa.

Abbreviations

LLIN: 

long-lasting insecticidal nets

IRS: 

indoor residual spray

NMCP: 

National malaria control programmes

Declarations

Acknowledgements

Author thanks Dr. Stephen Munga of Kenya Medical Research Institute, Kisumu, Kenya for his valuable critics during the development of this commentary.

Competing interests

The author declare that he has no competing interests.

Funding

This commentary work had no funds, Tropical Pesticides Research institute supported Internet access. Funding body had no role in the design of the study and collection of articles for review, analysis, and interpretation of gathered information and in writing this manuscript.

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors’ Affiliations

(1)
Division of Livestock and Human Diseases Vector Control, Tropical Pesticides Research Institute
(2)
Department of Medical Parasitology and Entomology, Catholic University of Health and Allied Sciences

References

  1. WHO. World Malaria Report 2015. Geneva: World Health Organization; 2016.Google Scholar
  2. Cibulskis RE, Alonso P, Aponte J, Aregawi M, Barrette A, Bergeron L, et al. Malaria: global progress 2000–2015 and future challenges. Infect Dis Poverty. 2016;5:61.View ArticlePubMedPubMed CentralGoogle Scholar
  3. Gnanguenon V, Agossa FR, Badirou K, Govoetchan R, Anagonou R, Oke-Agbo F, et al. Malaria vectors resistance to insecticides in Benin: current trends and mechanisms involved. Parasit Vectors. 2015;8:223.View ArticlePubMedPubMed CentralGoogle Scholar
  4. Huho B, Briët O, Seyoum A, Sikaala C, Bayoh N, Gimnig J, et al. Consistently high estimates for the proportion of human exposure to malaria vector populations occurring indoors in rural Africa. Int J Epidemiol. 2013;42:235–47.View ArticlePubMedPubMed CentralGoogle Scholar
  5. Bayoh MN, Mathias DK, Odiere MR, Mutuku FM, Kamau L, Gimnig JE, et al. Anopheles gambiae: historical population decline associated with regional distribution of insecticide-treated bed nets in western Nyanza Province Kenya. Malar J. 2010;9:62.View ArticlePubMedPubMed CentralGoogle Scholar
  6. Russell TL, Govella NJ, Azizi S, Drakeley CJ, Kachur SP, Killeen GF. Increased proportions of outdoor feeding among residual malaria vector populations following increased use of insecticide-treated nets in rural Tanzania. Malar J. 2011;10:80.View ArticlePubMedPubMed CentralGoogle Scholar
  7. Wamae PM, Githeko AK, Otieno GO, Kabiru EW, Duombia SO. Early biting of the Anopheles gambiae s.s. and its challenges to vector control using insecticide treated nets in western Kenya highlands. Acta Trop. 2015;150:136–42.View ArticlePubMedGoogle Scholar
  8. Reddy MR, Overgaard HJ, Abaga S, Reddy VP, Caccone A, Kiszewski AE, et al. Outdoor host seeking behaviour of Anopheles gambiae mosquitoes following initiation of malaria vector control on Bioko Island Equatorial Guinea. Malar J. 2011;10:184.View ArticlePubMedPubMed CentralGoogle Scholar
  9. Bugoro H, Iro’ofa C, Mackenzie DO, Apairamo A, Hevalao W, Corcoran S, et al. Changes in vector species composition and current vector biology and behaviour will favour malaria elimination in Santa Isabel Province Solomon Islands. Malar J. 2011;10:287.View ArticlePubMedPubMed CentralGoogle Scholar
  10. Magesa S, Wilkes T, Mnzava A, Njunwa K, Myamba J, Kivuyo M, et al. Trial of pyrethroid impregnated bednets in an area of Tanzania holoendemic for malaria Part 2. Effects on the malaria vector population. Acta Trop. 1991;49:97–108.View ArticlePubMedGoogle Scholar
  11. Kirby MJ, West P, Green C, Jasseh M, Lindsay SW. Risk factors for house-entry by culicine mosquitoes in a rural town and satellite villages in The Gambia. Parasit Vectors. 2008;1:41.View ArticlePubMedPubMed CentralGoogle Scholar
  12. Ogoma SB, Lweitoijera DW, Ngonyani H, Furer B, Russell TL, Mukabana WR, et al. Screening mosquito house entry points as a potential method for integrated control of endophagic filariasis, arbovirus and malaria vectors. PLoS Negl Trop Dis. 2010;4:e773.View ArticlePubMedPubMed CentralGoogle Scholar
  13. Njie M, Dilger E, Lindsay SW, Kirby MJ. Importance of eaves to house entry by Anopheline, but not Culicine, mosquitoes. J Med Entomol. 2009;46:505–10.View ArticlePubMedGoogle Scholar
  14. Lindsay S, Jawara M, Paine K, Pinder M, Walraven G, Emerson P. Changes in house design reduce exposure to malaria mosquitoes. Trop Med Int Health. 2003;8:512–7.View ArticlePubMedGoogle Scholar
  15. Snow WF. Studies of house-entering habits of mosquitoes in The Gambia, West Africa: experiments with prefabricated huts with varied wall apertures. Med Vet Entomol. 1987;1:9–21.View ArticlePubMedGoogle Scholar
  16. Spitzen J, Koelewijn T, Mukabana WR, Takken W. Visualization of house-entry behaviour of malaria mosquitoes. Malar J. 2016;15:1.View ArticleGoogle Scholar
  17. Wanzirah H, Tusting LS, Arinaitwe E, Katureebe A, Maxwell K, Rek J, et al. Mind the gap: house structure and the risk of malaria in Uganda. PLoS ONE. 2015;10:e0117396.View ArticlePubMedPubMed CentralGoogle Scholar
  18. Gillies M, Wilkes T. Evidence for downwind flights by host-seeking mosquitoes. Nature. 1974;252:388–9.View ArticleGoogle Scholar
  19. Lindsay SW, Emerson PM, Charlwood JD. Reducing malaria by mosquito-proofing houses. Trends Parasitol. 2002;18:510–4.View ArticlePubMedGoogle Scholar
  20. Atieli H, Menya D, Githeko A, Scott T. House design modifications reduce indoor resting malaria vector densities in rice irrigation scheme area in western Kenya. Malar J. 2009;8:108.View ArticlePubMedPubMed CentralGoogle Scholar
  21. Charlwood JD, Pinto J, Ferrara PR, Sousa CA, Ferreira C, Gil V, et al. Raised houses reduce mosquito bites. Malar J. 2003;2:45.View ArticlePubMedPubMed CentralGoogle Scholar
  22. Baraka V, Kweka E. The threat of Zika virus in Sub-Saharan Africa-the need to remain vigilant. Front Public Health. 2016;4:110.View ArticlePubMedPubMed CentralGoogle Scholar
  23. Chabi J, Baidoo PK, Datsomor AK, Okyere D, Ablorde A, Iddrisu A, et al. Insecticide susceptibility of natural populations of Anopheles coluzzii and Anopheles gambiae (sensu stricto) from Okyereko irrigation site, Ghana West Africa. Parasit Vectors. 2016;9:182.View ArticlePubMedPubMed CentralGoogle Scholar
  24. Worrall E, Fillinger U. Large-scale use of mosquito larval source management for malaria control in Africa: a cost analysis. Malar J. 2011;10:338.View ArticlePubMedPubMed CentralGoogle Scholar
  25. Hetzel MW, Reimer LJ, Gideon G, Koimbu G, Barnadas C, Makita L, et al. Changes in malaria burden and transmission in sentinel sites after the roll-out of long-lasting insecticidal nets in Papua New Guinea. Parasit Vectors. 2016;9:340.View ArticlePubMedPubMed CentralGoogle Scholar
  26. Thomson H, Thomas S, Sellstrom E, Petticrew M. Housing improvements for health and associated socio-economic outcomes. Cochrane Database Syst Rev. 2013;2:008657.Google Scholar
  27. Hunter M. The failure of self-reliance in refugee settlements. Polis J. 2009;2:1–46.Google Scholar
  28. Lawson DW, Borgerhoff Mulder M, Ghiselli ME, Ngadaya E, Ngowi B, Mfinanga SGM, et al. Ethnicity and child health in Northern Tanzania: maasai pastoralists are disadvantaged compared to neighbouring ethnic groups. PLoS ONE. 2014;9:e110447.View ArticlePubMedPubMed CentralGoogle Scholar
  29. Nangawe E, Shomet F, Rowberg E, McGinn T, van Wie W. Community participation: the Maasai health services project Tanzania. Int Q Community Health Educ. 1987;7:343–51.View ArticleGoogle Scholar
  30. Kahn M. Rural poverty in developing countries. Finance Dev. 2002;37:26–9.Google Scholar
  31. Dinar A, Hassan R, Mendelsohn R, Benhin J. Climate change and agriculture in Africa: impact assessment and adaptation strategies. London: Routledge; 2012.Google Scholar
  32. Barnard A. Anthropology and the Bushman. Oxford: Berg Publishers; 2007.Google Scholar
  33. Kalipeni E, Oppong J. The refugee crisis in Africa and implications for health and disease: a political ecology approach. Soc Sci Med. 1998;46:1637–53.View ArticlePubMedGoogle Scholar
  34. Nabie Bayoh M, Akhwale W, Ombok M, Sang D, Engoki SC, Koros D, et al. Malaria in Kakuma refugee camp, Turkana, Kenya: facilitation of Anopheles arabiensis vector populations by installed water distribution and catchment systems. Malar J. 2011;10:149.View ArticlePubMedPubMed CentralGoogle Scholar
  35. World Health Organization. Malaria control in humanitarian emergencies: an inter-agency field handbook. Geneva: World Health Organization; 2013.Google Scholar
  36. Burns M, Rowland M, N’Guessan R, Carneiro I, Beeche A, Ruiz SS, et al. Insecticide-Treated plastic sheeting for emergency malaria prevention and shelter among displaced populations: an observational cohort study in a refugee setting in Sierra Leone. Am J Trop Med Hyg. 2012;87:242–50.View ArticlePubMedPubMed CentralGoogle Scholar
  37. Mittal P, Sreehari U, Razdan R, Dash A. Evaluation of the impact of ZeroFly®, an insecticide incorporated plastic sheeting on malaria incidence in two temporary labour shelters in India. J Vector Borne Dis. 2011;48:138.PubMedGoogle Scholar
  38. Gore-Langton GR, Mungai J, Alenwi N, Abagira A, Bicknell OM, Harrison R, et al. Investigating the acceptability of non-mesh, long-lasting insecticidal nets amongst nomadic communities in Garissa County, Kenya using a prospective, longitudinal study design and cross-sectional household surveys. Malar J. 2015;14:52.View ArticlePubMedPubMed CentralGoogle Scholar
  39. White DJ, Davis P, Walter MH. Survey of repellent use by service members arriving in Kuwait for Operation Iraqi Freedom 2. Mil Med. 2005;170:496–500.View ArticlePubMedGoogle Scholar
  40. Messenger LA, Larsen MLM, Thomas JH, Rowland M. Installation of insecticide-treated durable wall lining: evaluation of attachment materials and product durability under field conditions. Parasit Vectors. 2014;7:508.View ArticlePubMedPubMed CentralGoogle Scholar
  41. Kweka EJ, Mazigo HD, Munga S, Magesa SM, Mboera LE. Challenges to malaria control and success stories in Africa. Global Health Persp. 2013;1:71–9.View ArticleGoogle Scholar
  42. Mellor JW. High rural population density Africa-What are the growth requirements and who participates? Food Policy. 2014;48:66–75.View ArticleGoogle Scholar

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