Office of Overseas Programming & Training Support (OPATS) Bed Net Distribution Malaria Prevention and Control
Session Learning Objectives : Having identified false statements about malaria, insecticides and resistance, participants will roleplay a conversation with adversarial community members and accurately and effectively respond to challenges about insecticide safety and resistance, and the benefits of universal bed nets in comparison to targeted use. Having read AMP Toolkit Chapter 3: Planning participants, working in small groups, will correctly sequence the steps of a bed nets distribution campaign. Having identified Peace Corps’ niche in bed net distribution activities, participants will list at least eight concrete actions they can take to engage or prepare for engagement in bed net distribution efforts at their sites. Provided with a bed net census form, working in pairs, participants will identify five key concerns and potential solutions in relation to obtaining an accurate count.
Bed Nets: A key strategy in malaria prevention LLINs are one of the four cornerstones of the WHO’s malaria prevention strategy. Over the past ten years LLIN production has increased dramatically (from 30 million to 150 million between 2004-2009 alone). Ensuring universal bed net coverage in all Peace Corps work zones is one of the three goals of Stomping Out Malaria in Africa.
The science shows that the use of Insecticide Treated Nets: – Reduces all-cause child mortality by 17% on average in sub-Saharan Africa (Lengeler C. Insecticide-treated bednets and curtains for preventing malaria. Cochrane Database of Systematic Reviews, 2000 ) – Reduces clinical episodes of uncomplicated malaria caused by Plasmodium falciparum and P. vivax by 50% and reduces incidence of severe malaria by 45% (Hill J, Lines J, Rowland M. Insecticide-treated nets. Advances in Parasitology, 2006) – Increases mean birth weight by 55 g, reduces low birth weight by 23%, and reduces miscarriages/stillbirths by 33% in the first to fourth pregnancies. Placental parasitaemia was reduced by 23% in all pregnancies (Gamble C., Ekwaru J.P., ter Kuile F.O. Insecticide-treated nets for preventing malaria in pregnancy. Cochrane Database of Systematic Reviews, 2006)
The Science shows that in [Insert Post name here] LLINs: [Post Adaptation – If available, insert data from a study on LLIN use done in your country. Good sources of research data are: PubMed - http://www.ncbi.nlm.nih.gov/pubmed/ and Google Scholar http://scholar.google.com/] http://www.ncbi.nlm.nih.gov/pubmed/ http://scholar.google.com/
What Volunteers are doing [Insert one or more examples of successful net-related malaria prevention activities that Volunteers are doing at post or in the region]
What do you know about malaria? – Malaria is transmitted by anopheles, culex and aedes mosquitoes. (a) true or (b) false? – The malaria-transmitting mosquitos take blood meals primarily between 4 and 8 pm. (a) true or (b) false? – After taking a blood meal many malaria-transmitting mosquitoes rest on the upper third of interior walls in order to digest (a) true or (b) false? – Mosquitoes take blood meals in order to provide energy for egg laying. (a) true or (b) false?
Mmmmm… People…. Mosquitoes are attracted to CO2, and body odors (especially from the feet) Some people produce more of the chemicals that attract mosquitoes Pregnant women produce more attractive chemicals The odors tend to waft up through the eves of houses – which is why mosquitoes arrive at the top rather than the side of bed nets.
Know your enemy Most bite inside, but some do not Most prefer to rest inside, but some like to get out in the fresh air All find humans tasty, but some also like cows Different breeding grounds Even within a country there may be different species of anophelene mosquitos in different regions that behave differently – see http://www.map.ox.ac.uk/http://www.map.ox.ac.uk/
Hanging together Deflection vs. Prevention Reducing burden on the HE system Why free? – People don’t value externalities – benefits that accrue to the community – WHO recommendations Incomplete Coverage Universal Coverage
Hanging together From a study done in Kenya in 2007. Note that even the people not using a net in the Universal Coverage zone were less likely to contract malaria than those outside the zone. From the same study, the danger of contracting malaria increased for those not using nets the farther they were from the center of the Universal Coverage Zone. C HANCE OF C ONTRACTING M ALARIA D ISTANCE FROM U NIVERSAL C OVERAGE Z ONE
Bed Nets: How do they work? Pyrethroid Insecticides – Deltamethrin (Permanet, Lifenet and others) – Alpha-cypermethrin (Duranet, Interceptor, etc.) – Permethrin (Olyset) Synergists (improve the effectiveness of pyrethroids) – Piperonyl Butoxide (Permanet 3.0) Pyrethroid Insecticides interfere with normal production and conduction of nerve signals in the insect nervous system Knockdown time of between 7-9 minutes (unwashed net) and 8-13 minutes (after 10 washes) – data from study of Permanet 2.0
Bed Nets: Not your grandpa’s net Advances in net manufacture allow for more open, breathable weave Some nets have insecticide coated on top of a polyester Others incorporate the insecticide inside the polyethelene or polypropylene fibers.
WHOPES, I did it again… WHO Pesticide Evaluation Scheme (WHOPES) established to coordinate testing and evaluation of pesticides for public health. WHOPES comprises a four-phase safety and effectiveness evaluation and testing program. All LLINs and chemicals used for Indoor Residual Spraying are certified by WHOPES.
Safety in numbers Mice fed the human equivalent of a teaspoonful of pure deltamethrin every day for the duration of a Peace Corps service show no treatment-related effects. Doctors prescribe permethrin to treat scabies. Alpha-cypermethrin is in the same WHO moderate toxicity ranking as the other two chemicals. All pyrethroids bind strongly to soils and therefore do not pose a significant risk to groundwater. The average half-life of the chemicals is 30 – 40 days. In other words, they stay put in the soil while waiting to (fairly rapidly) degrade into other compounds. For more info: National Pesticide Information Center npic.orst.edu
Resistance is everything A resistant A gambiae mosquito chills out on a mosquito net There is resistance to pyrethroids Mean Knock Down Time or KDT 50 is a common way of characterizing the amount of resistance - how long it takes to kill a mosquito. In Uganda a four-fold increase in KDT 50 was recorded after the introduction of universal coverage of nets. In Senegal, mosquito mortality decreased significantly partially due to agricultural use of pesticides. BUT
Resistance is futile Even with an increased KDT 50, mosquitoes still die. Children still receive a measure of protection. Malaria is averted. Things to remember: – Resistance isnt an all-or-nothing proposition: insecticides can still kill resistant mosquitoes – just more slowly – Even an untreated net provides a physical barrier – The hardest thing about bed nets distribution is getting people to use them. If people are in the habit of using them, as new insecticides are developed, more and more people will be protected. – Fitness costs of resistance mutations mean that resistance isn’t forever.
Correct the Errors Some of the following statements are incorrect. Identify those that are factually incorrect. Later you will consider culturally appropriate responses to community members who believed these assertions. 1.You can’t breathe underneath a bed net. 2.Bed nets are bad for your health. 3.Mosquitoes are more attracted to pregnant women. 4.The government said only kids under five need a bed net so I don’t need one. 5.I’ve gotten malaria every year, malaria isn’t dangerous, so I don’t need a bed net. 6.My government purchases cheap nets which don’t work. 7.I get bitten by mosquitoes all day, so it’s useless to use a bed net at night. 8.If God didn’t want us to get malaria he wouldn’t have created mosquitoes. 9.I heard there was resistance here, so nets are useless. 10.Insecticides are more dangerous than malaria.
Case Study Review What challenges do you believe Barbara and her counterparts will face on the day of distribution? What additional preparation could Barbara and her counterparts have done to minimize those challenges? To what degree will the distribution methodology outlined provide an equitable distribution of nets? What activities were planned to ensure that those who have nets use the nets? What additional activities might Barbara have done?
What did you do today at school? What did you learn today? What do you want to know more about? What do you not understand well?