Opinions on progress towards malaria elimination in Tanzania
Research scientists, regulators and policy makers discussed the progress made by Tanzania towards malaria elimination in terms of declining malaria prevalence as observed during the past decade. On the other hand, community members discussed the progress in terms of their daily life experiences.
Two major arguments emerged within this theme. On the one hand, it was agreed that the country had made good progress and was on the right track. On the other hand, it was also noted that the progress was slow and inadequate for elimination by 2030 as planned. Participants who emphasized that the country was on track referred to the significant reduction in malaria prevalence over the past decade, particularly noting that malaria has reduced by more than 50% since 2000. For example, one policy maker stated, “Of course we have come far from when prevalence was as high as 20% in the whole country. Back then when you look at the map it was all red, all red I tell you. There was malaria everywhere. But now you can see quite a lot of places that have prevalence of less than 1%, so when I see that I know that we are doing well.” (Female, Policy maker).
For community members, their idea of progress was informed mostly by their lived experiences. For example, they noted that the frequency and severity of malaria has greatly declined over the years, noting that unlike in the past when malaria infections were very frequent, several months could now go by without their children getting sick. Even when they did get sick, it was more likely not to be malaria. As one participant said, “Ten years back there was a lot of malaria. During that time, every time you did not feel well and went to the hospital you would be told that you have malaria. Kids were getting sick very often. But now we can go for even six months without our children getting sick or needing to go to the hospital. And when we do go we hear about other diseases like urinary tract infections or typhoid. So then I know that malaria is not a big disease like it used to be.” (Female, Community member).
There was also a group of participants who argued more cautiously that while there has been some progress, it is too slow, and does not reflect the amount of effort that the country has put in place. They also noted that the decline in malaria prevalence is not uniform across the country. As one policy maker reported, “I think we are doing well, but not as well as I would like. As a country we have put a great deal of efforts to finish off this disease, but I am sad to see that there are areas in the country where prevalence is as high as 40%. We should not be in a situation like this.” (Male, Policy maker).
Opinions on potential of current interventions in leading the country towards malaria elimination
Two main viewpoints were expressed regarding the potential of current interventions in leading the country through elimination by 2030. One viewpoint, expressed by a majority of the participants, was that current interventions would not be sufficient to achieve elimination even if they were utilized fully and effectively. One reason given was that the current interventions do not address challenges such as insecticide resistance and changes in mosquito biting behaviours. As one community leader explained, “I really do not think that the insecticide-sprays or the bed nets are enough, because if they were enough we would not have malaria anymore. I sleep under a bed net every night, but mosquitoes still bite me when I am outside cooking or chatting with my family and friends. Sometimes I also spray my house with insecticides, but when I go inside to sleep, I see there are mosquitoes still. So then I know that these sprays are useless.” (Female, Community member).
An opposite viewpoint was that the currently available interventions would be enough to lead the country through elimination if they were utilized to their maximum potential. As pointed out by one research scientist, “We already have what it takes to achieve elimination. If bed nets were properly made, properly distributed and properly used, why would we not eliminate the disease? If they killed mosquitoes as they are supposed to, if the universal distribution was actually universal, and if people actually slept under bed nets, I do not think we would need anything else…” (Female, Scientist).
Other participants pointed out that the current interventions are passive rather than active. That is, they only target mosquitoes coming to human dwellings rather than actively targeting them in their larval habitats and hiding places. As one policy maker stated, “We need means to target and eliminate all the mosquitoes, not just the ones that get inside the house. If we decide to kill mosquitoes, then we should really kill all of them. We should target them at larval stage and adult stage to make sure that we are not leaving any windows for escape.” (Male, Policy maker).
Opinions on the need for alternative interventions for malaria elimination in Tanzania
There were diverse inputs from participants on the need for complementary interventions for malaria elimination in Tanzania, although majority participants agreed that it would be unavoidable to have some of the alternative approaches used to complement current ones. Insights that emerged most clearly included: a) the importance of learning from similar countries that have achieved elimination, b) importance of knowing more about current interventions, including where or why they have failed or succeeded, and c) the need to consider combinations of interventions as a more holistic approach to achieve malaria elimination.
Those participants who emphasized the value of learning from other successful countries argued that there was no need to develop interventions from scratch, and that the country should follow in the footsteps of those who had been successful in eliminating malaria. Other participant noted that, since malaria prevalence was not homogeneous across the country, it would be essential to employ different interventions in different settings based on the specific conditions. For example, one participant stated, “Malaria prevalence is not the same in all the country. There are parts of the country that are near elimination, and there are parts that have prevalence in double digits. This should tell you that one single method is not enough for the whole country. You need to look at different places and figure out what can work where.” (Female, Regulator).
Participants who recommended combinations of interventions argued that we now have greater knowledge of mosquito behaviours than in the past, and that this knowledge can be used to target them from multiple angles to accelerate elimination. In one of the FGDs, one participant noted that “In order to really eliminate mosquitoes we need a combination of different strategies…We need to target all the water bodies to get rid of the larval stages, then all the hiding places like long grass and bushes, and then in the houses where they go to look for people to bite. If we do all of this, can you tell me how we can still have malaria in our country?” (Male, Policy maker).
There were also participants who suggested that it was not wise to rush to new interventions without learning from limitations of current interventions, and possibly addressing those first. In one session, there was an elaborate pronouncement by one policy maker, who noted that, “Why aren’t the bed nets killing mosquitoes? Why are the indoor insecticide sprays not killing mosquitoes? We have heard a lot about mosquitoes being resistant to the insecticides, but I still think we have not answered the question of where the resistance is coming from; what causes it and how it can be prevented or corrected. And also, do people know that the insecticides no longer kill mosquitoes? And if this is already a common knowledge, why are we still using these insecticides? I am sure that it costs a great deal of money to treat all the bed nets in the country with insecticides; but if these insecticides no longer work as insecticides, then why are we still using them?” (Male, Policy maker).
Opinions on the potential of the selected alternative interventions for malaria elimination in Tanzania
Discussions on alternative interventions for malaria elimination were based on participants’ opinions about their effectiveness, sustainability, safety, as well as about Tanzania’s readiness to adapt the interventions. There was a wide variation in levels of preference for different intervention options as described below:
Improved housing: All stakeholder groups associated improved housing conditions with reduced malaria risk. However, there were disagreements on need for the government to support transition towards better living conditions in malaria endemic communities. While community members were strongly supportive of this idea, policy makers were hesitant, pointing out issues of sustainability, affordability and competing government priorities.
The community members, in support of improved housing, argued that no intervention would be fully effective without adequate housing. Specifically, they noted that none of the other interventions under discussion would be particularly useful, if people continued to live in poorly-constructed houses with gaps on walls, roofs, doors and eave spaces. They further stressed that the government could indeed afford housing for the poorest community members living in areas with high malaria burden. The community members proposed several ways that the government could assist these communities, such as by providing loans for people to build improved houses, subsidizing prices for building materials or building and renting houses to the poorest at a reduced price. As one community member said, “If the government could listen, I would advise them to assist people, especially the poor people, to build improved houses. They can maybe build the houses, and people can repay the government slowly, everyone can pay according to what they can afford.” (Female, Community member).
Policy makers also agreed that improved houses provide extra protection against malaria-transmitting mosquitoes. However, they were against the idea of the government building or modifying houses for poor people living in areas of high malaria transmission. They noted that it is not the responsibility of the government to build houses for citizens, and that given the required magnitude, the program would be expensive and unsustainable. As one policy maker said: “You know our country is still poor, which means that a lot more people live in poverty than not. If you say that we start building or improving houses for all the poor people, then we will not have money for any of the other important things like health care and education.” (Female, Policy maker). Additionally, policy makers also indicated that building better houses alone would not be enough to eliminate malaria; a lot more effort would still be needed to ensure that mosquitoes are controlled in their larval habitats and hiding places.
Research scientists and regulators also agreed that it would be advantageous if poor people in malaria endemic areas had access to better housing. Nonetheless, they too noted that it would not be sustainable for the government to support this initiative, or even to get funding to investigate its potential. As one researcher noted: “For house improvement, no one denies that this works. The only problem is cost implications; that could be one of the reasons that this has not been taken up. Also, the way our research is organized and funded does not help in things like house improvement. It is difficult to get funding for this” (Male, Scientist).
Larval source management: Two strategies were discussed regarding this intervention: environmental management and larviciding (Table 1). However, most of the interest was directed towards larviciding. One major issue voiced by all stakeholder groups was lack of clear regulations or enforcement on environmental management regulations, especially in relation to settlement planning and waste water management. Community members complained about lack of regulations on where people build, cultivate crops or manufacture bricks for construction, which often results in the accumulation of standing water near settlements, increasing the risk of malaria and other mosquito-borne diseases. In the words of a community member, “The town is rapidly growing now. There were parts of the town that people were allowed to make bricks in the past; no one lived there at the time. But now many people live there, and it is not safe because there are so many brick-pits, hence so many mosquito breeding places…It would be important if there were requirements, [for example] that the brick makers move to other unoccupied places, or [that] they should be required to fill in the pits” (Female, Community member).
The use of larvicides for malaria control was highly preferred across the stakeholder groups, but with some caveats. Policy makers strongly supported the use of bio-larvicides, stating that the government had invested on creation of a bio-larvicide plant as part of the national strategy towards malaria elimination, but that use of this bio-larvicide remained low. “The biolarvicides we are producing are designed to only affect mosquitoes, so they are relatively safe on the environment. We expected a high uptake from community and civil organizations, but I am sad to say that we are getting more customers from outside the country than within the country….” (Female, Policy maker). Research scientists were also supportive of larviciding for malaria elimination, but they noted that the efficacy of the locally produced bio-larvicides should be evaluated since any perception of low efficacy might cause low uptake.
While a majority of the community members were in favour of larviciding for malaria control, a few members expressed concerns that there were so many water pools in their villages, particularly in the rainy season, that it would be difficult to treat all of them with larvicides without harming the environment, particularly the fish. One person stated: “I would also like to stress that I do not trust this idea of putting chemicals in water. We all know that all of this water makes its way into the river where we get our fish. If we treat all the pools then that means a lot of chemicals will be going to the river. Now, are you telling me that it will not harm the fish? Most of us are fishermen here and our fish is part of who we are. Anything that can harm the fish will not be welcomed here. Maybe if you want to put these chemicals, you can do it during the dry season, but then there are no many mosquitoes during this time, so it will just be a waste” (Male, Community member).
MDA using the endectocide, ivermectin: MDA with ivermectin is currently undergoing trials as a potential vector control tool, but there are already several completed trials demonstrating impact on mosquito populations and malaria burden (14,56). When given to humans and/or cattle, it kills malaria vectors that bite these hosts. The drug was widely known among all stakeholder groups as it is already widely distributed for control of lymphatic filariasis in humans (41,42) and several cattle diseases (57).
Community members referred to it as Usubi, and spoke of ‘health workers’ going from house to house every year to distribute the drug and encourage people to take it for control of Matende (elephantiasis) and Mabusha (hydrocele), conditions commonly associated with lymphatic filariasis. Despite the high awareness of this drug, there were mixed views among the stakeholder groups on its use for malaria control. Regulators, policy-makers and research scientists were hopeful and supportive of the approach, given its safety and effectiveness for control and treatment of lymphatic filariasis in Tanzania. They argued that deploying it for control of malaria-carrying mosquitoes would represent an important advantage at relatively low cost. They also stressed the need to spend time and resources to educate and raise awareness of the alternative use of ivermectin among target communities.
Community members on the other hand had strong objections to this intervention, reporting negative experiences with previous mass drug administration (MDA) campaigns, particularly of Praziquantel, which is commonly used for treatment and control of schistosomiasis among school children. They reported that a number of children who received the drug suffered fainting spells in schools, and this resulted in negative sentiments among community members. They also noted that generally people did not like to take medicines. One participant stated: “I really must tell you that these medicines that you have to swallow have a challenge. When they brought Usubi, even with all the education and the advocacy they had provided, people still did not take the medicines. Some people just picked it so as not to make the health workers feel bad, but after they [health workers] left people threw the medicine away.” (Male, Community member).
Targeted spraying of mosquito swarms: A great deal of scepticism was expressed by all stakeholder groups about sustainability and feasibility of targeted spraying of swarms of Anopheles mosquitoes. It was noted that the approach would require extensive community participation, and would be expensive. One participant stated: “The setback with this is that you need a lot of people to do that, so it may also be expensive. But I agree maybe you use less insecticides, but if you are worrying about the cost of the insecticides, you will still be spending more in paying people to spray” (Male, Policy maker). Community members also pointed out that it would be inconvenient to spray at the time of the day when mosquitoes swarm and in many of the locations where they do so: “…it will be difficult to find someone at home during that time, people will still be at work, or they will be too tired to accept more work.” (Male, Community member).
Modified mosquitoes: This possibility of releasing modified mosquitoes generated a lot of discussions and resulted in polarized viewpoints among all stakeholder groups. Although groups were introduced to different technological approaches constituting mosquito modification (i.e., sterile insect technique, genetically modified-sterile mosquitoes and gene drive technology), most of the interest centered on implications of gene drive technologies, particularly those used for suppression of malaria vector populations.
Scientists were the most critical of gene drive technology. They questioned its safety and the country’s readiness for such advancements. They also pointed out that there are still a lot of unknowns, and that long-term research would be needed to provide evidence on various aspects of the technology. They expressed concerns about possibility of mutations in either the Plasmodium parasite or the modified mosquitoes themselves. Specific concerns in this case were that the modified malaria vectors could become vectors for other diseases or the Plasmodium parasite could mutate and survive in other mosquito species. The fact that the technology would target a single malaria vector was also seen as a risk as this could possibly increase the prevalence or vectorial capacity of the other malaria vectors. Targeting one mosquito species was also seen as a drawback in securing community acceptance. One participant stated: “For the people, no malaria means no mosquitoes. They still cannot distinguish between malaria-transmitting and non-malaria transmitting mosquitoes, so if you tell them that you are controlling malaria then they need to see mosquitoes gone.” (Female, Scientist). The scientists were also concerned that there were not many African and particularly Tanzanian scientists taking leading roles in this research. One scientist stated: “There are more fears than certainty regarding this technology. It is mainly being driven by foreigners. I worry that there are not many African researchers participating in the detailed research of this technology” (Female, Scientist).
Policy makers were divided in their views regarding gene drives. Some were in favor of it, pointing out that it was environmentally friendly and required little compliance from communities, yet others were skeptical, noting that there is currently a great deal of controversy over genetically-modified food products, thus it might be unwise to introduce another genetically-modified organism. One policy maker said; “We are already struggling with acceptance of GM crops, adding yet something like this may bring havoc in the country. Let them [other countries] try it first, let us learn from our neighbours and go last in this.” (Female, Policy maker). The policy makers also recognized that the technology is not yet ready, and cannot be considered in the 2030 malaria elimination campaigns.
In contrast, and significantly, community members expressed a great deal of fascination with the technology. They were struck in particular by the fact that it will require little work or participation from residents, compared to traditional malaria interventions. They also expressed a preference for this technology since it was seen to pose the least harm to the environment, particularly to fish. One participant said: “I like that it does not have any chemicals, so the environment and the fish are all safe, but the malaria-mosquitoes will be gone (Male, Community member).
Regulators pointed out that, while the potential of gene drive technologies ought to be explored, there are currently no policies and regulations for their governance, and in order to put those in place, more research is needed to assure short- and long-term safety. One participant said: “There are regulations for GMOs, but this technology you have is not GMO, rather GM edited organisms. Gene-edited is not the same as GMO. We do not have policies or regulations for that. I believe you can advise us on this; provide all the information needed and the evidence of its safety and we can add this into the regulations concerning GM organisms” (Female, Regulator).
Spatial repellents: All stakeholder groups agreed that this technology would be appropriate as complementary (rather than primary) intervention for malaria control and elimination. Scientists however indicated that there was still insufficient evidence to indicate the best spatial repellents, and their availability, cost and feasibility of use.
Community members spoke positively about this technology, saying that it was most useful when people were outdoors in early night hours, when cooking, eating and relaxing with their family and friends before going indoors to sleep. They alleged that it would be best if the government could distribute bed nets together with spatial repellents as a package in order to tackle the problem of mosquitoes changing their behaviours. One participant stated: “We have been told that mosquitoes are clever and have changed their biting times, so we have to be smart too and respond to that change using these repellents. If the government can provide these repellents to every household and teach them when, where and how to use them, I think we can make a very big progress in ending the malaria problem.” (Female, Community member).