Open access peer-reviewed chapter - ONLINE FIRST

Dancing in a Cycle: Global Health Agenda and Schistosomiasis Control in Africa

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Adetayo Olorunlana

Submitted: December 26th, 2021 Reviewed: February 10th, 2022 Published: April 20th, 2022

DOI: 10.5772/intechopen.103164

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Parasitic Helminths and Zoonoses - From Basic to Applied Research Edited by Jorge Morales-Montor

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Parasitic Helminths and Zoonoses - From Basic to Applied Research [Working Title]

Prof. Jorge Morales-Montor, Dr. Víctor Hugo Del Río-Araiza and Dr. Romel Hernández Bello

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Abstract

Schistosomiasis and other Neglected Tropical diseases (NTDs) affect about 2 billion people globally. Africa shares approximately 90% of the global burden of schistosomiasis disease. Despite, World Health Organization (WHO) effort to control the disease, it remains neglected in most African countries. Historically, schistosomiasis is as long as 4,000 years in Africa, but lack accurate data and commitment to combat the disease. Control programs exclude adults in Mass Drug Administration (MDAs), and water, sanitation, and hygiene (WASH) as Praziquantel drug is used for the treatment. However, migratory patterns of the neglected population and the interplay of social, economic, political, and cultural factors introduce the disease into previously eliminated or/and new areas. The question is would Africa be able to achieve the new goals of the WHO NTDs 2021–2030 Roadmap, for schistosomiasis elimination? The chapter argued for and against if Africa changes the current top-down approach to schistosomiasis control and incorporates a dynamic approach. Or if the previous pattern of late implementation, dependent on only one drug and shifting focus to other diseases of relevance continues. If a new approach is not adopted the dance in the cycle has just begun.

Keywords

  • Africa
  • control programme
  • neglected tropical disease (NTDs)
  • Praziquantel
  • Schistosomiasis

1. Introduction

Schistosomiasisis among the Neglected Tropical Diseases (NTDs), and the main challenge is the control of the disease [1]. Schistosomiasistransmission has been reported from 78 countries with over 65% in Africa with estimated 800 million people at risk of the disease [2, 3]. Literature affirmed that Schistosomiasisis the third-highest burden among parasitic NTDs, 2019 estimation of the World Health Organization peg the infection at over 140 million people and at least 236.6 million people required preventive treatment and it remains among the major global health threats [4, 5, 6]. Consequently, schistosomiasisis still highly endemic in several countries especially in Sub-Saharan Africa [5, 6, 7, 8, 9].

Scientifically, schistosomiasiscould be a mild, acute, and chronic parasitic disease caused by blood flukes (trematode worms) of the genus Schistosoma[2, 6]. Africa shares not less than 90% of the global burden of schistosomiasisdisease necessitating her need for preventive chemotherapy (see Table 1) in about 51 endemic countries with moderate-to-high transmission [6]. There are five different types of species causing schistosomiasisinfection: Schistosoma haematobiumaffecting the urinary tract; Schistosoma mansoni, Schistosoma japonicum, Schistosoma intercalatum, and Schistosoma mekongiaffecting the intestine. S. haematobiumand S. mansoniinfections are common in Africa [9, 10].

CountriesEstimated number requiring preventive chemotherapy for SchistosomiasisannuallyEstimated number of school-age children requiring preventive chemotherapy for Schistosomiasisannually
AlgeriaNo PC requiredNo PC required
Angola5,034,8073,258,115
Benin2,300,0111,367,350
Botswana1,395,735366,693
Burkina Faso4,737,9984,285,046
Burundi1,701,4801,633,550
Cabo Verde5,674,5103,835,446
Cameroon5,670,7133,329,839
Central African Republic (CAR)1,216,727477,715
Chad3,990,2752,378,434
ComorosNon-endemicNon-endemic
Congo, Democratic Republic15,977,68011,521,955
Congo, Republic421,246225,225
DjiboutiNo PC requiredNo PC required
Egypt2,932,8151,464,425
Equatorial Guinea62,86432,196
Eritrea286,629243,835
Eswatini402,727282,396
Ethiopia14,979,3397,774,638
Gabon180,080160,0The 42
The Gambia180,080160,042
Ghana10,685,2014,369,206
Guinea4,435,0481,864,900
Guinea-Bissau160,922108,416
Kenya3,519,3211,924,082
LesothoNon-endemicNon-endemic
Liberia875,416447,595
LibyaNo PC requiredNo PC required
Madagascar9,914,9964,438,987
Malawi8,861,7683,735,144
Mali6,276,7153,518,177
Mauritania844,271390,854
MauritiusNo PC requiredNo PC required
MoroccoNo PC requiredNo PC required
Mozambique16,564,1366,264,395
Namibia486,997203,961
Niger10,249,6204,553,187
Nigeria26,289,93117,444,157
Rwanda2,784,9351,685,462
Sao Tome and Principe39,69824,126
Senegal2,614,8161,340,844
SeychellesNon-endemicNon-endemic
Sierra Leone3,002,8791,309,396
Somalia2,847,5922,549,993
South Africa4,628,8433,807,757
South Sudan2,841,5841,324,002
Sudan8,080,7064,515,705
Tanzania16,495,0746,750,656
Togo3,051,9131,740,023
TunisiaNo PC requiredNo PC required
Uganda12,305,7915,628,177
Zambia4,268,9092,338,006
Zimbabwe3,413,1542,021,614

Table 1.

Status of Schistosomiasisin 54 African countries showing the estimated number of people and school-age children that required preventive chemotherapy (PC) in the year 2020.

Source: Compiled by Author 2021; extracted from WHO [33].

In Sub-Saharan Africa (SSA), S. mansoni(intestinal schistosomiasis) and S. haematobium(urogenital schistosomiasis) (Table 2), transmitted through feces and urine, has been identified as the main species causing human schistosomiasis[11]. Research shows that S. mansoniis widely distributed across the tropics and subtropics especially in the vast poverty-stricken but environmentally and climatically friendly sub-Saharan Africa [12, 13]. Some reported that S. haematobiumis the most prevalent parasite in Nigeria, with an estimated population of 30 million people annually [8, 14]. Also, S. haematobiumis affirmed to be more endemic because of the agricultural activities such as fishing, subsistence farming, and washing among others that forces the rural people to interact with freshwater [15, 16].

SpeciesGeographical distribution
Intestinal schistosomiasisSchistosoma mansoniAfrica, the Middle East, the Caribbean, Brazil, Venezuela, and Suriname
Schistosoma japonicumChina, Indonesia, the Philippines
Schistosoma mekongiSeveral districts of Cambodia and the Lao People’s Democratic Republic
Schistosoma guineensisand related S. intercalatumRain forest areas of central Africa
Urogenital schistosomiasisSchistosoma haematobiumAfrica, the Middle East, Corsica (France)

Table 2.

Parasite species and geographical distribution of schistosomiasis.

Source: WHO [33].

Subsequently, the population experiences schistosomiasissymptoms like anemia, fever, genital lesions, stunting, and sometimes irreversible organ damage [17]. This was the rationale behind the preventive chemotherapy (PC) and the recommendation of Praziquantelby WHO as a notable strategy to control schistosomiasis by targeting the school-aged children (SAC) from aged 5–15 years because they were most infected and can be reached successfully through schools [5]. “The PC strategy is indicated by prevalence (estimated by initial parasitological assessment) at implementation unit level, usually, district, the prevalence of infection less than 10% requires triennial PC, 10% to 49% biennial treatment, and 50% or greater annual treatment” [5].

Although some countries recorded success of morbidity control, the narrative is different in most African countries. If some countries were able to eliminate schistosomiasis, some scholars have asked the question why not Africa [18]. Could it be argued that the COVID-19 Pandemic hinders the WHO set goals for the control and elimination of schistosomiasisin 2020? Or could we measure the progress so far and project that the WHO will achieve the goal of elimination of Schistosomiasisas a public health problem in all endemic countries by 2025 or 2030? Complete interruption of transmission is a target in selected regions by 2025 [19, 20, 21, 22, 23]. Although strategic plans exist on how the WHO guidance on how schistosomiasiscan be controlled and scale up to elimination [18, 20], but is yet uncertain if such goals can be achieved with the little time left [23]. The current review traced the historical analysis of schistosomiasis, exposed the neglected nature of the disease as a possible reason for persistent transmission, ex-rayed the burden and the challenge of elimination, explained the use of preventive chemotherapy and the proposition for African traditional medication, finally concluded with the global health agenda and schistosomiasiscontrol campaign in Africa.

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2. Historical analysis of Schistosomiasisin Africa

Historically, scholars assumed that schistosomiasisin Africa must have originated from Egypt during the Egyptian mummies of the twentieth dynasty around 1250–1000 B.C. because of the symptoms characteristic of urinary schistosomiasiswhich were first described in early Egyptian papyri and the eggs of S. haematobiumidentified in the urinary tracts approximately around 4000 years ago [23, 24].

According to Di Bella, there were reports of persistent haematuriarecorded by members of Napoleon’s army in Egypt in 1798 [24], and in forces involved in the Boer war (1899–1902). In the Eastern Cape of South Africa, schistosomiasiswas first recorded in 1863, after Dr. J Harley diagnosed endemic haematuriawith unknown cause in residents which cause was only known 11 years after. Although schistosomiasisaffects all age categories but was more common in children in South Africa between 1864 and 1899 this was associated with contact with freshwater [23, 25]. Although certain studies claimed that women and girls were considered to be less affected as they had little contact with “natural” water but other studies claimed they are more likely to be affected because they have more contact with freshwater [2, 25].

The name schistosomiasiswas given by a German physician called Theodore Bilharz as he was the first to identify the parasite causing schistosomiasisin 1851. In his study he recovered two distinct species from autopsies of dead soldiers in Egypt and first named the parasite Distomum haematobiumand also described hatching of eggs, linking the existence of the parasite to clinical symptoms– primarily haematuria–attributed to the disease [23]. Bilharzia was later adopted as the generic term for the schistosomiasisparasites after the German physician Theodore Bilharz.

In Africa, cultural interference influenced the way schistosomiasissymptoms are described. For example in Nigeria among Song people in the North, schistosomiasis is a sign of manhood; among the Yewa people in Southwestern, is called “Atosiaja”as a result of urinating where dogs urinated, while Anambra people in the Eastern part of Nigeria called it “ogbodu”meaning red urine, as a sign of venereal disease; a sign of maturity or a result of a curse, malaria fever, witchcraft or dirtiness [26]. In north Cameroon, the Fulbe people relate red urine to “cille naange”(sun urine), in Upper Egypt, is seen as “harzia”, a serious disease that weakens people, eats the liver, and causes blood loss, bladder stones, calcium disease and other afflictions [26]. In most of the African descriptions of Schistosomiasis, water contacts or snails were not mentioned. General knowledge of the disease causation and the perceived severity may influence people a little toward the disease.

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3. Factors promoting the neglect of Schistosomiasisand reasons for persistent transmissions

Author and colleagues [2], emphasize the place of human culture in the persistent transmission of schistosomiasis, in Nigeria. Their emphasis was based on human behavior related to occupation, recreation, and daily house chore that necessitate the people to have contact with freshwater bodies that carries the snail with the schistosomiasislava. Notably, schistosomiasisis one of the 20 NTDs, is a water-based parasitic disease of public health importance [27].

The NTDs in the early 2000s was categorized as 17 conditions in the WHO portfolio [1, 28], there was a varied group of communicable diseases caused by bacteria, helminths, protozoa, or viruses, such as Buruli ulcer, Chagasdisease, dengue, dracunculiasis(guinea worm disease), echinococcosis, foodborne trematodiasis, human African trypanosomiasis(sleeping sickness), leishmaniasis, leprosy, lymphatic filariasis(elephantiasis), onchocerciasis(river blindness), rabies, schistosomiasis(snail fever), soil-transmitted helminthiasis(intestinal worms), taeniasis/cysticercosis(pork tapeworm), blinding trachoma, and yaws [1, 28]. Since 2016, this list was expanded with three groups of diseases to currently include 20 NTDs or groups of NTDs. Those new NTDs include mycetoma, chromoblastomycosis, and other deep mycoses; scabiesand other ectoparasites; and snakebite envenoming[1].

Generally, Africa lacks accurate data on the NTDs, moreover, the constant contact with water containing S. haematobium cercariaereleased from the Bulinussnail, often occurs regularly, resulting in re-infection with the disease [27], this also affects the data on the prevalence of schistosomiasisin Africa. Using documented evidence in data gathering, research shows that adult worms could live in humans for as long as 30 years [29]. When humans host the worm for such long a time in endemic areas it becomes possible for infection or/and re-infection at some point in their life [27], leading to a vicious cycle within the communities irrespective of preventive chemotherapy. For example, statistics affirmed that the highest schistosomiasisdisease burden globally can be found in Nigeria (see Table 1), however, Nigeria does not have accurate national data on schistosomiasisprevalence. Although, she sometimes embark on a large-scale deworming implementation exercise for SAC in endemic areas with praziquantel[30], neglecting the adults and out-of-children as they were not covered by mass administration of praziquantelwould be a challenge to the control of the disease.

Sometimes, the affected communities and individuals affected by schistosomiasistend to neglect the symptoms, depending on the stage of the infection, because of the wide range of clinical symptoms that may occur, many of which are hard to distinguish from several other diseases [15]. It was also argued from the perspectives of the medical sociologist as perceived by the people as a disease but not an illness [26]. From that argument, the affected community does not see schistosomiasisas a serious ailment since they can go about their daily business without being bed riding. However, a study shows that schistosomiasis causes morbidity with many infected persons experiencing hematuria, dysuria, bladder-wall pathology, and hydronephrosis[27]. But because these conditions are not peculiar to schistosomiasisalone it tends to be neglected.

From the Nigeria scenario as related to other sub-Sahara Africa, is the cost for diagnosis and tool kits that inform the diseases being neglected. Nigeria did tackle schistosomiasisthrough a 2-step approach: case management and a control program [31]. According to Isere and colleagues, in the case management approach, cases are diagnosed at the primary care level. While for the control program, school-aged children are given praziquantelfor the treatment of schistosomiasis. Sturrock [32], affirmed that schistosomiasisis common among children with the highest intensity of infection found in children between ages 5 and 15 years. However, the study also revealed that women and men carry a high risk of urinary schistosomiasisdue to social and occupational activities such as farming and washing, especially in areas with poor water, and sanitation services [2]. Water-related domestic activities such as washing clothes and fetching water, as well as recreational water activities also increase the risk of infection for women and children [33]. It is also more common in fishing and agriculture dominant communities where direct interactions with water increase the risk of contracting the disease.

Other concerns for schistosomiasisbeing tag neglected disease include missed diagnosis, need for more sensitive, accurate, cheaper, and easy to use devices for the diagnosis and control of schistosomiasis. Study shows that several persons do not pass bloody urine which is characteristic of the disease [34]. Notably, most of the control program does not include adults in MDAs [30], meaning that adults with schistosomiasis infections are not being treated. “Schistosomiasis haematobiuminfection is mainly diagnosed using microscopy to detect parasite eggs in urine specimens which are not sensitive in detecting light infections of <50 eggs per 10mls of urine; while labor-intensive, and sensitivity of diagnosis depends on the skill of the laboratory personnel” [35]. “Also, egg excretion in urine varies daily and can be complicated by interaction between the host and the parasite” [36]. There are other tests for the detection of S. haematobiuminfection, but they are contested for their poor specificity and high cost for endemic countries [37]. Although some of the tests are useful they are at the stage of schistosomiasiselimination, a phase that the majority of the African countries are yet to reach [17]. From the various range of factors and the tendencies for continuous transmission, it is certain, that the challenge and burden of the schistosomiasiswill be burdensome.

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4. Schistosomiasisburden and the challenge of eliminating the disease in Africa

Schistosomiasisdisease burden is high in Sub-Saharan Africa [38]. This is because Sub-Saharan Africa accounts for not less than 93% of the world’s burden of diseases. As of 2015, there were about 207 million schistosomiasiscases, with the highest prevalence found in Nigeria, Tanzania, Ghana, Mozambique, and the Democratic Republic of Congo, these 5 countries account for 78 million cases [39]. In this region, after Nigeria, Tanzania was the second country having the highest cases of schistosomiasisand approximately 51.5% of the Tanzanian populations were either exposed or live in areas with a high risk of exposure [40], in current data [6] Mozambique has slightly overtaken Tanzanian (See, Table 1).

To combat schistosomiasis, WHO did develop numerous roadmaps for NTDs, and significant progress has been made by many sub-Saharan African countries by rolling out national action plans and programs targeting schistosomiasiscontrol and elimination [7]. Considering all these efforts, we are tempted to ask why is it that schistosomiasisstill remains a huge problem in sub-Saharan Africa? With such an unmet need for the treatment [5]. Conversely, over 150 000 deaths are attributable to chronic infection with S. haematobiumin Africa [41]. Researchers affirm that schistosomiasiscommonly affects the poor, the majority of them living in rural, underprivileged urban, or peri-urban settings with limited access to clean water, inadequate sanitation, and lack hygienic services [42]. Schistosomiasisburden is beyond health impact it also has social and economic implications for communities [39].

Children are at a greater risk of acquiring the infection as well as reinfection [43]. Schistosomiasisis known to cause anemia, growth stunting, and reduced productivity; and accounts for between 1.6 and 4.2 million disability-adjusted life years (DALYs) lost annually in sub-Saharan Africa [42, 44, 45]. New data show a reduction of an estimated 1.43 million DALYs lost to schistosomiasisin 2016 globally [46]. However, in aggregate schistosomiasiswith other NTDs were estimated to affect close to 2 billion people at the turn of the millennium, with a collective DALYs burden that was equivalent to HIV/AIDS, tuberculosis, or malaria [47]. There exist indirect consequences of NTDs, which are beyond condemning affected people to live long years with disability and stigma, it was noted that it keeps children out of school, adults out of work, burden households with considerable costs to seek health care, trap communities in endless cycles of poverty and cost developing economies billions of dollars every year [48].

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5. Mass drug administration and its inadequacy to control Schistosomiasisin Africa

Schistosomiasiscontrol and elimination involve several strategies ranging from disease treatment to managing complications and controlling disease transmission with a combination of preventive chemotherapy dispersed through MDAs, and water, sanitation, and hygiene (WASH) programs [7, 19, 49, 50]. The focus of the WHO plan for schistosomiasiscontrol and elimination is on preventive chemotherapy, particularly MDAs in sub-Saharan Africa [51]. Although some progress has been made such as partnerships with donor foundations, interventions of international organizations like Merck the producer of praziquantel,and the exercise of large-scale treatments [7, 52]. There is because Praziquantelhas been considered cost-effective, relatively safe, inexpensive, and effective; with donor organizations willing to provide the drug at no cost making it the only viable choice for the treatment of schistosomiasis[19].

Praziquantelis the key bullet for schistosomiasiscontrol and elimination, however, Onasanya and colleagues [51], observed that in practice is reactive instead of proactive and is an unavoidable consequence of a one-size-fits-all approach. According to them, this reactive approach is limiting for several reasons. They stated that firstly, despite the “efforts at making praziquantelavailable to those in need and Merck KGaA’s commitment to praziquanteldonations, targets for MDAs coverage have still not reached all people at risk who require treatment” [51, 53]. This they said, “may indicate an under-representation or undercount of cases based on low-level awareness” [8, 12, 54], the disease may be introduced to new or previously eliminated areas due to our migratory patterns [4, 55, 56], it is safe to assume that the similarity of the disease makes its transmission easy across different tropical regions and countries. For example, countries like Nigeria have prioritized praziquantelfor SAC but leave out adults and preschool children during MDAs [54]. In this context, it implies that schistosomiasiscannot be effectively eliminated in communities where MDAs treatment is on-ongoing.

Secondly, it was noted that, although there is a commitment to the donation of praziquantel, there is a high chance of recrudescence of disease to pre-MDAs levels once donations reduce or cease, or even during MDAs programs [57, 58]. Thirdly, “praziquantelitself has not demonstrated 100% curative ability in both single-dose and multi-dose regimens in various settings, implying that relying only on praziquanteltreatment use during MDAs is not an effective strategy for control and elimination of this disease” [59, 60, 61]. Fourthly, “given the neglected nature of the disease in most healthcare systems in sub-Saharan Africa, there is currently inadequate funding for the disease from the national governments which is likely to persist or worsen in the future once the current external funding and support are reduced. They also noted that there is also a potential for donor fatigue as current gains in treatment to be reversed when donation stops because countries do not have sustainable strategies to own and incorporate programs within their current healthcare systems” [62].

Lastly, Onasayan and colleagues submitted that the disease context is complex with an interplay of social, economic, political, and cultural factors that may affect achieving the goals of the NTD 2021–2030 Roadmap [56, 63, 64]. Affirming that in light of the daunting challenges, there is a need to revisit the current top-down approach to schistosomiasiscontrol among sub-Saharan African countries irrespective of the level of the endemicity. From the angle of WHO, there have been several resolutions over time toward the control and elimination of schistosomiasis, including renewing interest, addressing partnerships, for example in 2012, the need to attach importance to both preventative and control strategies by developing applicable plans with progressive targets was initiated [20]. Moreover, “in 2013, the WHA66.12 resolution on NTDs focused on advocating for continuous country ownership of programs for NTD prevention, control, elimination, and eradication” [7, 49]. “The current roadmap for 2021–2030 for NTDs also reiterates the importance of community-based and applied research for effective NTD programs, it highlights the need to integrate mainstream approaches into national healthcare systems, coordinate action across sectors, and close coordination and multi-sectoral action across all sectors” [50].

We may wonder if enough literature has not been done on schistosomiasiscontrol. But Mazigo and colleagues [65], simply noted that planning and implementation of schistosomiasiscontrol activities requires an understanding of the prevalence, intensity of infection, and geographical distribution of the disease in different epidemiological settings. It is safe to assume that the reasons why preventive chemotherapy strategy for schistosomiasisfails sometimes are the lack of understanding of the geographical distribution of the disease and the infection level in endemic communities living in different geographical settings [65]. For effectiveness, therefore, Mazigo and colleagues [65], pointed out the importance of identifying areas where infections have continued to be a public health problem despite repeated rounds of MDAs. Noting that this will allow the development of focused integrated control measures. Generalizing from Tanzania research, they affirmed that in many of the schistosomiasisendemic countries, there is inadequate attention given to research on the geographical distribution of schistosomiasisin other areas outside the historically known and highly researched areas.

5.1 Use of preventive chemotherapy and proposition for Africa traditional medication to control Schistosomiasis

If schistosomiasisaffects the intestine and is not attended to in the time it can become complex and lead to critical organ failure [66, 67]. To prevent this, the single dose of praziquantel(PZQ) has been prescribed as a first-line treatment since 2005 with the remarkable success achieved against schistosomiasisthrough targeted mass chemotherapy [52]. According to Moon [68], PZQ was discovered in the 1970s and approved for human use in the United States of America in 1982. For effectiveness and in pursuant of elimination of schistosomiasis, preventive treatment should be repeated over several years, to reduce and prevent morbidity [6].

Some progress has been recorded by the World Health Organization (WHO), in 2017 for example, it was estimated that out of at least 290.8 million infected people, and about 98.7 million were treated for schistosomiasis[69]. The statistics account for less than 30% of the infected population receiving treatment. What possible factors could be responsible for the low coverage? Hotez, and colleagues [70] attributed the inadequate coverage to cost. Other scholars argued that PZQ has its limitations. For instance, it has the property that reduced prophylacticeffect at the recommended doses against immature stages [71, 72]. Others claimed that there is little data on PZQ safety and efficacy in preschool children leading to the exclusion of this age group from chemotherapy preventive control programs [73], and others said that there is no oral formulation for infants and preschool children [74]. It was even concluded that the drug has no effect if the liver and spleen are seriously affected [33].

A report from Nigeria shows treatment once annually with praziquantelfor schistosomiasisinfections, which is said to be effective for the treatment of all species of schistosomiasis[39]. According to some scholars [75], this program was said to have been achieved through school-based deworming (SBD) carried out by the State Ministries of Health in collaboration with the Federal Ministry of Health Nigeria (FMoH), WHO, and other nongovernmental organizations (NGOs). This program according to research [30], offers treatment of all school children in the country. However, due to the poor environment as well as poor hygiene behavior by individuals, reinfection occurs rapidly after treatment.

Though PZQ appears safe and effective against all adult Schistosomiasisspecies in general [76], further research is needed to understand the efficacy and safety of various doses for different Schistosomaspecies. “Some studies reported PZQ therapeutic failure up to 40%” [77, 78]. What should be the main concern? First is the heavy reliance on the single available drug, which studies show has been in use for the past 40 years. Secondly, is the tendencies for drug resistance which is an eventual scenario for any drug, and PZQ cannot be an exception [79]. Hence, there is a need to search for novel drugs against all schistosomiasislifecycle, (see Figure 1) and the stages of the parasite with considerations for both pediatric and adult use.

Figure 1.

Schistosomiasis life cycle. Sources: CDC [10]. Available at:https://www.cdc.gov/parasites/schistosomiasis/biology.html.

Onasanya and colleagues seem confused because of the lack of clarity on how sub-Saharan African countries would achieve the targets beyond the desire for easy wins through the use of praziquantelas a reactive way to achieve the aims of control and elimination of schistosomiasis[51]. They stated that if schistosomiasiscontrol is to be attained, then it will require a dynamic approach that incorporates more proactive and holistic strategies beyond the current top-down approach. Affirming that such an approach most of the necessity incorporates the socio-cultural, epidemiological, economic, and geographical dynamics within each country to create a mix-set of feasible strategies for schistosomiasiscontrol.

Consequently, the WHO calls for the need to eliminate schistosomiasisby 2030, and proposed the development of new intervention tools and alternative drugs to PZQ [52]. Scholars are of the view that most modern drugs have their root in traditional medicine, as noted that nearly 30% or more of the modern pharmacological drugs are derived directly or indirectly from plants [80, 81]. Notably, African people are majorly from low-income countries relying heavily on traditional medicine for the treatment of all forms of ailment including schistosomiasisand other parasitic diseases [26]. In Ethiopia a large number of communities, particularly in rural areas, rely on traditional medicinal plants to fight several diseases including schistosomiasis[82, 83], this is not different from Ghana, Nigeria, Mali, Senegal, and other African countries. One scholar argued that the reasons why people practice traditional medicine are the high cost of modern drugs, paucity and inaccessibility of modern health services, and cultural acceptability of traditional medicine [82]. However, observation shows that in health pathways some African combine both modern and traditional medicine in health help-seeking behavior. Some participants in Nigeria affirmed that there are medicinal plants that have already shown therapeutic efficiency against schistosomiasisinfection [26]. When will the goal of total elimination of schistosomiasisbe achieved?

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6. Global Health Agenda and Schistosomiasiscontrol campaign in Africa

The global health agenda can be traced to the World Health Organization and the World Health Assembly (WHA) in 1975, when the Executive Board called for an international conference to address the conspicuous inequalities in health and health services between countries [84, 85]. In the said conference WHA adopted the call to scale up efforts in drug development, proper engineering design of water management projects, and mobilization of partners for schistosomiasiscontrol [86]. In the following year, in 1976, a resolution was passed on the need to consider the epidemiological aspects of the disease during the planning and implementation of water management schemes in endemic countries [23]. The resolution considered the need to implement measures to prevent the spread of schistosomiasisto new geographical locations [87]. In 1977, WHA specified that the central social goal of WHO was the level of “acceptable” health that would allow a “socially and economically productive life” for all people by 2000 and called on nation-states to work toward this goal [85]. To pursue this agenda, the primary health care framework was formulated at the Alma-Ata conference in 1978 [88]. The purpose of the Alma-Ata Declaration was to influence strategies, policies, and programs of national and global communities for the next two decades. The declaration emphasized the need to provide “Health for All” by adequate collaboration between biomedical and traditional sectors, in order to encourage encompasses approaches to health care that incorporated community development and community participation [85].

Oyeyemi and colleagues noted that while these efforts recorded some positive outcomes in some countries, the situations in sub-Saharan African countries were rather the same [23]. Another research confirmed the lack of interest in the schistosomiasiscontrol campaign in sub-Saharan Africa as other diseases were given more priority in the region’s health agenda [89]. Little or no efforts were recorded between the 1970s after the Agenda to the year 2001 when significant results were expected. For example, Oyeyemi and colleagues said there was no single record of an epidemiological study on schistosomiasisin some Nigerian States [23]. They, however, agreed that most of the notable schistosomiasiscontrol strategies in Nigeria started in the late 2000s.

Over the years, several resolutions aimed toward improvement on schistosomiasiscontrol have been made with great commitment but little or no achievement, portraying the African countries like a dancer, dancing around in a cycle. However, there seems to be a resurgent in recent years, as the control of schistosomiasisand other NTDs started to have some level of awareness and taken the priority list of some African governments, international organizations, and donors among others [7]. The resurgent can be traced to the WHA 54.19 resolution on schistosomiasisand soil-transmitted helminths on attaining at least 75% regular treatment benchmark of all school-aged children in endemic communities by 2010, endorsed in 2001 by the WHO member states [23, 90]. But it took more than a decade for some countries to come up with a national action plan for the control of NTDs. For example, a well-organized control implementation for the schistosomiasisprogram was only supported after the year 2010 by the Nigerian government [23]. As of January 2012, when WHO published NTDs Roadmap, it described the strategic approach to fast-track work to overcome the global impact of NTDs, targeting the period of 2012–2020 [91]. These resolutions received the overwhelming support of donors, member states, and other stakeholders who pledged their support for the WHO Roadmap and its 2020 target [51, 91], in the same 2012, the WHA 65.21 resolution on the elimination of schistosomiasiswas endorsed [92].

Consequently, all affected regions (See, Figure 2 and Table 3) are to strengthen the control interventions and surveillance and embark on schistosomiasiselimination where possible [19]. So, in the year 2013 WHA 66.12 resolution on NTDs, member states were to take ownership of NTDs’ various control programs [49]. Then, between the years 2015 and 2020, three time-bound goals for control of schistosomiasiswere set by the WHO NTD Roadmap for the Mediterranean Region, Americas, Western Pacific, and sub-Saharan African countries [7, 23]. Oyeyemi and colleagues, assert that although the WHO NTDs Roadmap envisaged the potential elimination of schistosomiasisin some countries in the sub-Saharan region by 2020, it was certain that this feat was unachievable by the end of 2020 [23]. They assumed that conflict in the Nigerian communities might have contributed to the non-realization of the control of schistosomiasis. They also alluded to the COVID-19 pandemic as a possible impediment to schistosomiasiscontrol implementation programs in Nigeria. The question is, would the WHO NTDs 2020 target have been realized in the absence of conflict and the current pandemic? The answer is possibly a no, going by the previous patterns of attention given to previous resolutions. It was, however, affirmed that epidemiological evidence suggests that the country has a long way to go and a new WHO NTDs Roadmap for control or elimination of schistosomiasisis inevitable [23], now that there is a new roadmap for 2021–2030 [52]. Following the previous pattern of late implementation, the presence of other diseases of priority such as COVID-19 and incessant conflict in Africa, are we not going to be singing the same song of a long way to go? We may need time to tell, since the new resolution just began, it may be too early to judge if it will succeed or fail.

Figure 2.

Principal places affected by Schistosomiasis in Africa. Sources: MDPI [93]. Available at:https://www.mdpi.com/2414-6366/6/3/109.

NameValue
Africa218,779,749
Americas2,252,917
Eastern Mediterranean17,275,612
EuropeanNot applicable
South-East Asia24,179
Western Pacific2,937,454
Global241,269,911

Table 3.

Schistosomiasis global statistics.

Source: WHO [33].

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7. Conclusion

Historically schistosomiasisin Africa can be traced to the Egyptian mummies of the twentieth dynasty, it has spread over the continents with the highest global burden in the world. Despite several efforts brought forth to combat the disease is still categorized among the neglected tropical diseases for several reasons. It is not all affected populations that are treated during MDAs, also certain symptoms look like that of other diseases, mode of transmission also are associated with the people social and occupational activities, sometimes schistosomiasisis missed diagnosis and devices for the diagnosis are expensive. The high cost of logistics and the exclusion of adults and out-of-school children during mass drug administration are possible factors that promote continuous transmission of schistosomiasisin Africa. Schistosomiasisand other NTDs affect close to 2 billion people with other indirect consequences such as disability, stigma, truancy, abscond from duty, poverty, and economic loss. With all the concerted effort of government, donors, and WHO, the MDAs is still inadequate to control schistosomiasisin Africa. Maybe because of the inadequate attention is given to research on the geographical distribution of schistosomiasis in other areas outside the researched areas. There is current advocacy for the use of traditional medicine as an additional effort to combat schistosomiasis in Africa. This is because several declarations and roadmap for the control and elimination program have failed, we hope that the 2030 target will be a success.

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Conflict of interest

The authors declare no conflict of interest.

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Note

I deeply appreciate my wife and children, for their understanding, when I was supposed to have time for them during the Christmas holiday, they allowed me to concentrate on the write-up, love you dearly.

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Written By

Adetayo Olorunlana

Submitted: December 26th, 2021 Reviewed: February 10th, 2022 Published: April 20th, 2022