malaria elimination

This manual was developed through the work of numerous WHO staff and international partners in malaria control, to whom we are most grateful. For their guidance, input, and comment on the Elimination Scenario Planning manual, we would like to thank: Justin Cohen, Deepika Kandula, Bruno Moonen and Oliver Sabot from the Clinton Health Access Initiative, USA; Azra Ghani, Jamie Griffin, Thomas Churcher and Lucy Okell from Imperial College, UK; David Smith from Johns Hopkins University, USA, and Andy Tatem from the University of Southampton, UK; Roly Gosling and Allison Phillips from the University of California San Francisco’s Global Health Group, USA; Richard Steketee from the Malaria Control and Evaluation Partnership in Africa (MACEPA) and Allan Schapira, independent consultant in malaria and tropical diseases; Michael Lynch, Robert Newman, Richard Cibulskis, and Aafje Rietveld from WHO-GMP. We would also like to thank the following participants in a workshop on malaria elimination scenario planning held in Banjul, The Gambia, in May, 2012, for their valuable feedback on the ESP manual and accompanying malaria tools software: Adam Sonko, Balla Kandeh, Momadou Kalleh, Balla Gibba, Malick Gai, and Mamodou from the National Malaria Control Programme, The Gambia; Umberto D’Alessandro, Serign Ceesay, Joseph Okebe, Medical Research Council Unit, The Gambia; Cheikh Diop, Medoune Diop, Ousseynou Badiane, Jean-Louis Ndiaye from the Programme National de Lutte contre le Paludisme, Senegal; Boniface Mutombo, Yakou Dieye, MACEPA, Senegal.

In addition, the authors recommend that elimination programmes implement monitoring and evaluation of activities to assess the social impact of elimination pro- grammes. While this commentary warns of the potential for elimination discourse to lead to social harm, it is only through evaluating programmes and carrying out social impact assessments that programmes can ascer- tain whether their activities in fact carry unintended so- cial implications. As programmes become more targeted in local areas, strengthened community engagement may also add local knowledge to programmes and help pro- grammes become more responsive to localized dynamics influencing malaria transmission. Since resources often become constrained in elimination settings, it will be ne- cessary to continue advocating for sufficient resourcing to enable elimination efforts to continue and to reduce the risk that outbreaks may be blamed upon communities. Rather than risk profiling and targeting narrow demo- graphic groups, strengthened community engagement efforts will help to ensure that programmes provide accur- ate information to communities about the value of pursu- ing malaria elimination. This will help to ensure that communities nearing elimination can respond to any fu- ture disease outbreaks in ways that decreases the risk that elimination programmes will contribute to social harm but rather help to strengthen elimination efforts.

access to preventive measures such as ITN or effective chemotherapy will impact on parasite rates. While spa- tially expansive, surveys of this type are temporally lim- ited and may not indicate fluctuations in transmission rates that could occur at other times of the year or in different seasons. Malariometric surveys previously con- ducted on the island of Espiritu Santo in Vanuatu indi- cated that parasite rates varied between wet and dry seasons as did species composition with P. falciparum dominant in the wet season and P. vivax dominant in the dry season [23]. The present surveys in Tafea and Temotu Provinces reported here were conducted towards the end of the wet season when transmission would be at its peak. Despite this the overall malaria prevalence was only 2-3% with a predominance of vivax malaria. This follows a trend, which commenced in the early 1990 s, towards lower transmission rates for these remote island groups, and for the other Provinces in both Solomon Islands and Vanuatu as well [2,5,6,30]. Despite the development of chloroquine resistance in P. falciparum and in to a lesser degree P. vivax during the 1980 s [18,19], the downward trend in malaria has been driven by a general improvement in the overall health of the community, promotion of a greater awareness of malaria, and the efforts of the respective national Vector Borne Disease Control Programs through better access to treatment and vector control measures [30,35]. One can use the proportion of vivax malaria as a rough gauge of malaria elimination suitability as malaria con- trol activities preferentially stop falciparum malaria transmission leaving residual liver parasites of Plasmo- dium vivax to relapse and re-infect mosquitoes months to years later. After malaria transmission is stopped, incident vivax malaria cases will more likely be due to relapses from liver parasites and not recrudescences from asymptomatic bloodstream infections.

In 2007, the Australian Government initiated through the Department of Foreign Affairs and Trade’s external aid organization, AusAID, a programme to support Vanuatu and Solomon Islands in their efforts to control and if feasible eliminate malaria from the islands. Known as the Pacific Malaria Initiative (PacMI), this programme is supported through the Pacific Malaria Initiative Support Centre (PacMISC), a consortium made up of the School of Population Health at the Uni- versity of Queensland, the Australian Army Malaria Institute and the Queensland Institute of Medical Research. As an entry point to enhanced malaria control possibly leading to elimination, malariometric surveys were conducted in the southern-most provinces of both Vanuatu (Tafea Province) and Solomon Islands (Temotu Province) during 2008 by the National Vector Borne Disease Control Programs in each country with Pac- MISC support. (See orientation map, Figure 1.) This report contains the results of the two surveys and attempts to extend these point prevalence observations towards what may evolve into a malaria elimination pro- gramme for both nations.

Abstract: In 2010 deaths from malaria in Nigeria were the highest recorded worldwide. This was a strange phenomenon since so much effort has been geared towards eradicating this dreaded disease in the country, hence the need to critically investigate the reasons for these challenges confronting eradication efforts. There is need to identify some of the setbacks confronting malaria elimination in Nigeria. Some of the challenges x-rayed include: inadequate healthcare infrastructure in the rural areas, poor drug distribution, increases in drug resistant parasites, increase in insecticide resistant mosquitoes, poverty leading to poorly constructed rural dwellings with cracks and crevices, and individuals’ non-compliance with the control program due to high level of illiteracy. Much work still need to be done to reduce malaria incidence to a minimum level in Nigeria. No single individual method can be used to achieve a successful malaria control program. Strategic control methods must involve some combination of effective clinical control, vector control, reduction in contact of the mosquito with its human host, improved sanitation, and better health education and malaria prevention programs. If these efforts are sustained, over time Nigeria may succeed in eradicating malaria.

lessons highlight a range of challenges and opportunities for the malaria community. The major challenges relate to obtaining a global consensus to endorse a defined strategy focusing on elimination, and developing tools to support the business case. Economic modelling is required to de- velop robust cost-benefit modelling that focuses on elimin- ation targets. This is a core need for ongoing elimination advocacy. Some of these lessons involve extending existing efforts. For example, the malaria community has a history of developing messages and communications tools; the current opportunity is to extend this work to incorporate elimination targets. Similarly, there are a number of global and regional malaria partnerships that could provide a plat- form for elimination advocacy - these partnerships need to be provided with the mandate to focus on elimination, with a clear structure of coordination. Most importantly, these lessons also highlight opportunities for the malaria com- munity to embrace new approaches. Advocates for malaria elimination can work within developmental frameworks - building synergies with other health and social pro- gramming - to maximize outcomes from investment and prevent competition for increasingly scarce resources. Engaging effectively with communities is vital for build- ing support and optimizing local implementation that is essential for effective long-term programming.

The resurgence of malaria in Swaziland in early 1970 occurred as a result of the migration of sugar cane workers from malaria-endemic Mozambique (Martens and Hall, 2000; Packard, 1986). More recently, the current migra- tion of labourers into Swaziland from Mozambique is likely to be a challenge for Swaziland’s stated plan of malaria elimination by 2015 (Koita et al., 2013). The rapid rise in malaria incidence in Brazil in the late 1970s and early 1980s was attributed to the influx of malaria-infected migrants from endemic Bolivia (Cruz Marques, 1987). The resurgence of malaria in Costa Rica resulted due to the development of the banana industry in which workers were moved from endemic areas into areas with increased suitability for vector breeding (Najera et al., 1998). The oil-exporting countries of the Middle East have attracted a large number of semiskilled workers from malarious countries such as India, Pakistan and Indonesia, who are a source of malaria introduction (Schultz, 1989). The importation of malaria to Kuwait occurs mostly from the Indian subcontinent (Hira et al., 1988, 1985; Iqbal et al., 2003). Saudi Arabia is an attractive employer of skilled workers from malaria-endemic countries such as Iran, Pakistan and India, as well as east Africa (Bruce et al., 2000; Babiker et al., 1998). The main source of malaria cases in the UAE is from Pakistan and neighbouring Oman, including families of UAE nationals living across the border in Oman (Dar et al., 1993). These examples highlight the important role that economic migrations have in re-establishing malaria in areas where con- trol efforts had previously been successful.

Where significant differences from Europe at the time of malaria elimination exist, they are in climatic con- ditions. Higher temperatures, increased precipitation and fewer frost days all suit malaria transmission, mak- ing present-day elimination countries more receptive to transmission, and thus more of a challenge in terms of achieving elimination than was the case in Europe [46, 47]. Nevertheless, many European countries remain receptive to transmission today, but outbreaks rarely occur, despite significant numbers of imported cases [48]. A combination of factors is likely behind these ‘sticky’ states [5, 6], and some of these are related to economic development, land use and health systems, which have made elimination sustainable. With today’s elimination countries approaching or exceeding the levels that Euro- pean countries were at when elimination was achieved, it seems feasible that they are moving towards similar sticky elimination states.

Results: Both malaria-related morbidity and mortality have decreased significantly across all three malaria-endemic provinces since 2000. The greatest decline was seen in KwaZulu-Natal where cases decreased from 42,276 in 2000 to 380 in 2010 and deaths dropped from 122 in 2000 to six in 2010. Although there has been a 49.2 % (8,553 vs 4,214) decrease in the malaria cases reported in Limpopo Province, currently it is the largest contributor to the malaria incidence in South Africa. Despite all three provinces reporting average insecticide spray coverage of over 80%, malaria incidence in both Mpumalanga and Limpopo remains above the elimination threshold. Locally transmitted case numbers have declined in all three malaria provinces but imported case numbers have been increasing. Knowledge gaps in vector distribution, insecticide resistance status and drug usage were also identified. Conclusions: Malaria elimination in South Africa is a realistic possibility if certain criteria are met. Firstly, there must be continued support for the existing malaria control programmes to ensure the gains made are sustained. Secondly, cross border malaria control initiatives with neighbouring countries must be strongly encouraged and supported to reduce malaria in the region and the importation of malaria into South Africa. Thirdly, operational research, particularly on vector distribution and insecticide resistance status must be conducted as a matter of urgency, and finally, the surveillance systems must be refined to ensure the information required to inform an elimination agenda are routinely collected.

Malaria elimination is back on the agenda, but it remains challenging for countries to make the transition from effective control to elimination. Many other infectious diseases have been targeted by globally-coordinated elimination advocacy campaigns, and advocacy has been considered an essential component of the success of other disease elimination programmes. What can the malaria community learn from these successes? A review of infectious disease elimination programmes to identify successful elements of advocacy for disease elimination was undertaken. Key elements are: (i) a global elimination plan, supported by international health bodies; (ii) thorough costings and tools to support the business case; (iii) an approach that is positioned within a development framework; (iv) core elimination advocacy messages; (v) provision of advocacy tools for partners (vi) extensive and effective community engagement; and (vii) strong partnerships. These features provide insights into ‘ what works ’ in global elimination advocacy. Advocacy is a powerful tool to support the long-term political and financial commitment necessary for malaria elimination. The global malaria community needs to work together, to ensure that the early steps towards the end goal of malaria elimination are taken.

The impact of regional climate phenomena on malaria transmission was also studied recently. Bouma et  al. showed that El Niño conditions might have contributed to the 2016–2017 malaria outbreaks in Ethiopia [16]. Hashizume et  al. also observed that the Indian Ocean Dipole (IOD) exhibits a 4-year cycle coherent with malaria seasons in the East African highlands [38]. Severe flooding due to extreme rainfall have also caused malaria outbreaks in the highland areas of western Uganda [39]. Although the multivariate El Niño Southern Oscilla- tion Index (MEI) is not strongly associated with malaria transmission risk in Swaziland, public health authorities should nevertheless be vigilant of future climate changes and extreme local weather events that may affect ongoing malaria elimination strategies. For instance, vector con- trol should continue along with case management, since the Anopheles spp. remains active in Swaziland.

Regional efforts such as the Lubombo Spatial Development Initiative [35] and the Asia Pacific Malaria Elimination Network [51,52] are excellent examples of where cross border collabora- tions have succeeded in addressing the challenge of imported malaria. Today, seven countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, the United Arab Emirates and Yemen) remain committed to supporting intensification of malaria control efforts on the Arabian Peninsula [20]. It is clear that reinvigoration of the border collaboration with Yemen will be necessary to achieve a malaria-free Saudi Arabia by 2015. Novel strategies of quickly identifying imported cases should also be considered. Recent work in Swaziland, a country also targeting elimination by 2015, has shown that snowball and time-location sampling can quickly identify networks of individuals at high-risk of bringing malaria into the country [53]. Adoption of this approach in Saudi Arabia would allow for targeted screening and treatment, preventing onward transmission. Additional strategies may include parasite genotyping, which would allow more accurate determination of common sources of infection.

If complete malaria elimination is the goal, vivax malaria must be eliminated in regions where it is prevalent. A dif- ferent approach from that used for P. falciparum elimina- tion is required because of differences in the life cycle of the two parasites. A typical MP is only equipped to treat the asexual blood stages of P. vivax. Plasmodium vivax gametocytes emerge much earlier in the course of an infection, sometimes prior to clinical presentation. EDT is therefore not expected to be as efficient at breaking the transmission cycle of P. vivax compared with P. falcipa‑ rum [8, 62]. Plasmodium vivax is characterized by liver- stage hypnozoites which cause relapsing blood-stream infections without exposure to new infective bites. These hypnozoites are not killed by chloroquine and relapses are therefore not prevented by early treatment at the MP [63]. The only available treatment for the radical cure for P. vivax is a 14-day course of primaquine but it is rarely used because of poor adherence and potential toxicity in case of G6PD deficiency [64, 65]. Point-of-care G6PD tests and better treatments of the hypnozoites are needed to eliminate P. vivax.

Malaria remains a major health burden especially for the developing countries. Despite concerted efforts at using the current control tools, such as bed nets, anti malarial drugs and vector control measures, the disease is accountable for close to a million deaths annually. Vaccines have been proposed as a necessary addition to the armamentarium that could work towards elimination and eventual eradication of malaria in view of their histori- cal significance in combating infectious diseases. However, because malaria vaccines would work differently depending on the targeted parasite stage, this review addresses the potential impact various malaria vaccine types could have on transmission. Further, because of the wide variation in the epidemiology of malaria across the endemic regions, this paper proposes that the ideal approach to malaria control ought to be tailor-made depending on the specific context. Finally, it suggests that although it is highly desirable to anticipate and aim for malaria elimination and eventual eradication, many affected regions should prioritize reduction of mortality and morbidity before aspiring for elimination.

As the number of malaria cases is falling worldwide, more asymptomatic, submicroscopic malaria reservoirs are being found [4–6], which require detection strate- gies different to those for symptomatic, microscopic infections. It is known that asymptomatic cases repre- sent parasite reservoirs that contribute to malaria trans- mission [5, 7], but to what degree is unknown [6] and depends on various host and parasite factors [5, 7, 8]. Among these, the production of mature gametocytes in adequate densities is necessary to transfer the parasite from humans to mosquitoes [7, 9]. Other factors include host immune responses and the duration of the infection [4, 10]. Guatemala currently participates in the initiative Elimination of Malaria in Mesoamerica and the Island of Hispaniola (EMMIE initiative) sponsored by the GFATM, whose activities are oriented to facilitate regional efforts towards malaria elimination [11]. However, since partici- pating countries have only recently begun these efforts, there is a knowledge gap regarding how these strategies should be implemented in the region [12, 13]. While studies on the detection of asymptomatic, submicro- scopic reservoirs and gametocyte carriers are becoming more common worldwide, none have been published from Mesoamerica. This study aimed to assess whether asymptomatic, submicroscopic reservoirs with gameto- cyte carriers exist in this region, to help guide novel con- trol and elimination strategies in Mesoamerica.

The diagnosis of malaria parasites by nested PCR in the present assessment is at medium level with an accur- acy of 84.21% (48/57). The ease and speed of PCR makes it an important tool in malaria elimination programmes and should be improved to detect asymptomatic infec- tions. Since various PCR methods have been developed for malaria diagnosis [40-44], it is necessary to compare the benefits of different methods, optimize the protocol, and train staff in the reference laboratory network. Mean- while, more samples with different densities should be in- cluded in future QA activities.

The practice of labelling migrants, indigenous groups and poor rural communities as ‘hotpops’ or ‘reservoirs of infection’ is concerning, since these discourses are directed at groups that often already face multiple forms of structural violence. Although malaria may be culturally normalized in some societies where it is still common, mal- aria programmes operating in elimination settings should be aware that programmes are increasingly seeking to target narrowly defined demographic groups that are often already social vulnerable. As the authors argued in a review of the literature on malaria and population mobility [35], recent elimination programmes have painted an exagger- ated image of mobile populations as segregated from local communities, engaged in illegal activities and avoiding authorities. Williams and colleagues [14] have expressed concern about the way that elimination discourse describes displaced persons as a threat to programme success, while comparatively little attention is given to their health needs. While the discussion about ‘reservoirs of infection’ is clearly intended to inform accurate surveillance strat- egies, it also uses highly negative language to describe groups as a source of infection. While not suggesting that malaria elimination programmes are currently gen- erating negative impacts through elimination discourse, the potential for this to occur is evident. As malaria re- duces it will be important for malaria elimination pro- grammes to consider how malaria is understood within this changing socio-political context – especially when managing malaria imported malaria and disease out- breaks – and to develop strategies that are aware of the changing socio-political context in which elimination programmes operate.

The recent scale-up of malaria interventions, the ensuing reductions in the malaria burden, and reinvigorated dis- cussions about global eradication have led many countries to consider malaria elimination as an alternative to maintaining control measures indefinitely. Evidence-based guidance to help countries weigh their options is thus urgently needed. A quantitative feasibility assessment that balances the epidemiological situation in a region, the strength of the public health system, the resource constraints, and the status of malaria control in neighboring areas can serve as the basis for robust, long-term strategic planning. Such a malaria elimination feasibility assess- ment was recently prepared for the Minister of Health in Zanzibar. Based on the Zanzibar experience, a framework is proposed along three axes that assess the technical requirements to achieve and maintain elimination, the operational capacity of the malaria programme and the public health system to meet those requirements, and the feasibility of funding the necessary programmes over time. Key quantitative and qualitative metrics related to each component of the assessment are described here along with the process of collecting data and interpreting the results. Although further field testing, validation, and methodological improvements will be required to ensure applicability in different epidemiological settings, the result is a flexible, rational methodology for weighing differ- ent strategic options that can be applied in a variety of contexts to establish data-driven strategic plans.

China has had remarkable success in controlling locally transmitted malaria through several initiatives facilitated by increased funding, including: effective vector control, strengthening of health systems, improving case man- agement with more effective treatment regimens, and enhanced case reporting and surveillance [8]. Since 2010, annual numbers of reported malaria cases have fallen to unprecedentedly low levels, with only hundreds of autochthonous malaria cases now occurring in limited areas [9–11]. In 2010, the Chinese government launched the national malaria elimination programme with the goal of eliminating malaria nationwide by 2020 [12]. However, China shares more than 22,000 km of land bor- der with 14 neighbouring countries, six of which are still malaria-endemic [3, 13, 14]. Malaria from these coun- tries, especially Myanmar poses a major threat to the achievement and maintenance of national malaria elimi- nation [15]. Although there were checks in international land borders, population movement between China and other malaria-endemic countries becoming even more frequent was still a high risk of malaria infection. The epi- demiological situation in these high-risk areas needs to be further investigated. In this study, the changing risk of malaria occurrence in all counties with international land borders was explored following the initiation of the Chi- nese malaria elimination programme in 2010, in order to identify remaining high-risk areas, formulate response measures and allocate resources for malaria elimination.

Brazil currently contributes 42 % of all malaria cases reported in the Latin America and the Caribbean, a region where major progress towards malaria elimination has been achieved in recent years. In 2014, malaria burden in Brazil (143,910 microscopically confirmed cases and 41 malaria-related deaths) has reached its lowest levels in 35 years, Plasmodium falciparum is highly focal, and the geographic boundary of transmission has considerably shrunk. Transmission in Brazil remains entrenched in the Amazon Basin, which accounts for 99.5 % of the country’s malaria burden. This paper reviews major lessons learned from past and current malaria control policies in Brazil. A compre- hensive discussion of the scientific and logistic challenges that may impact malaria elimination efforts in the country is presented in light of the launching of the Plan for Elimination of Malaria in Brazil in November 2015. Challenges for malaria elimination addressed include the high prevalence of symptomless and submicroscopic infections, emerging anti-malarial drug resistance in P. falciparum and Plasmodium vivax and the lack of safe anti-relapse drugs, the largely neglected burden of malaria in pregnancy, the need for better vector control strategies where Anopheles mosquitoes present a highly variable biting behaviour, human movement, the need for effective surveillance and tools to identify foci of infection in areas with low transmission, and the effects of environmental changes and climatic variability in transmission. Control actions launched in Brazil and results to come are likely to influence control programs in other countries in the Americas.