Fighting River Blindness in Africa

Introduction

The river blindness also is known as Onchocerciasis is a deadly disease that afflicts an estimated number of about 40 million people across the globe (15). Notably, 99 per cent of the victims are residents of sub-Saharan African. River blindness disproportionately burdens the people living in remote and poorest areas in Africa. A negligible number in Yemen and Latin America are also affected (10). In most affected areas, it has been denoted that one-third of the adult population is represented by blind individuals. The infection approximately forms 90 per cent of the population (5). Onchocerciasis is caused by a warm referred to as Onchocerca volvulus. The warm gets into the human body through a bite of an infected blackfly. According to Kim (2015), in conducive riverine environments where the flies breed, it has been shown that the residents are bitten approximately 10000 times per day. The worm grows 2-3 feet in length while inside human producing millions of microfilaria (9). The continuous movement of the microfilaria in the infected person's skin causes a wide range of symptoms such as rashes, skin lesion, weakness, muscle pain and in adverse cases it can result in blindness. Currently, about 500 thousand people are blind as a result of Onchocerciasis (Dadzie et al., 2018). Notably, about 1.5 million persons have serious visual impairment. Health burden aside, river blindness causes adverse damage in the social and economic status of people in the whole community (5). The primary objective of this paper is to focus on the implemented strategies that have been employed to assist in the elimination of the river blindness in sub-Saharan African countries.

How onchocerciasis spread? Studies shows that the disease spread from one person to another if an individual is bitten by an infected blackfly (11). When a person infected by the river blindness is bitten by the blackfly, a microscopic warm commonly referred to as microfilariae present in the infected person skin gets into the blackfly. The worm develops inside the fly for about two weeks to a point that it can infect humans (6). According to Crump (2012), an infectious blackfly often drops the microscopic worm while biting a person. The skin of the person is then penetrated by the worm to infect the person. The fact that larvae produce exclusively in humans and should end some of their development inside the fly, the severity of the infection will depend on the number of bites a person is exposed to for a given period. Blindness will occur as a result of intense infection due to longstanding bites (5). Of the 34 countries that Onchocerciasis is endemic, 27 come from Africa. Special attention is given to Sub-Sahara Africa because in some hyperendemic villages, the rate of infection is about 100% which is significantly large compared to, say, Latin America where the figure is less than 10% (9). Even when a person is heavily infected with Forest strain O. volvulus, they are not likely to get blind. They however, may weak strains of ocular ailments. This strain is found in rainforest coastal regions. There is direct proportionality in endemic savannah places in Africa in microfilarial load of a given community and cases of blindness found therein. The immunity of the host plays a major role in determining load of worms present. This coupled with age are important factors in endemicity of Onchocerciasis. As such, this partly explains why children under the care of mothers infected with O. volvulus are more likely to get infected at young age. Back to regions that do not fall within savannah, the disease’s attribute of showing itself mainly through the skin is the major complexity of the ailment (14). Ghastly skin lesions and associated psychosocial implications. Over half of lost DALYs as a result of onchocerciasis is largely due to skin ailments.

When taking into consideration community impact felt, we establish valid relationship between endemicity of O.volvulus and pruritus occurrence. Note the cycle of prevalence found in hyperendemic regions. These are areas defined as facing thorough outbreak with only more than 60% of those with microfilardermia with more than 30% onchocercomas. The fact that about half all kids 5-9 years already have onchocerciasis. There is little hope in coming out of this vicious cycle of infection (2). This disease affects the eye and skin. It is caused by a parasite. The blackfly transmits the parasitic worm (fialria) to humans. They breed in rivers flowing in intertropics and once female worms get into a human body, they lay as much as 1000 eggs daily. Their death is the main cause of symptoms faced in eyes and skin. One aspect of endemicity is seen by large cases of blind men in some regions (upwards of 50%) such that people forced to take care of them are at risk of infection (11). Cases of poverty are abated by the disease as people are forced to run from arable properties to safer lands which are not necessarily fertile. The disease draws its name from the fact that the host of the parasite always breed in streams in remote places. These rivers have fast rate of flow and their presence is directly related to reliance of locals on agriculture.

Appreciate the fact that focus concerned body has shifted from merely controlling it to elimination. In West Africa, Onchocerciasis Control Programme (OCP) was mandated in 1974 to control prevalence of the new menace at that time and some successes were achieved. It is probable that they played a major role in helping to shift focus. They treated about 40 million people, saw to it that about 600000 did not go blind and made sure that more than 18 million infants were not infected by their mothers. Also, about 25 million ha of arable land was salvaged. This was the government catching up with the long unattended endemicity of this ailment. It was a stepping stone for the elimination stage (5). Healthcare in Sub-Sahara Africa ranks the lowest in the world. The poor patients are forced to finance more than half the cost of care with out-of-pocket financing. Attention from well-wishers has improved quality of care in select diseases leaving out some. Also, shortage of competent staff and improper infrastructure impede delivery of quality healthcare. Other major hindrances include high mortality rate with the continent having 95% of its members in the list of 20 nations with the most maternal mortality rate. Also, it has most number of neonatal deaths.

Note that poor and middle income nations do not have appropriate parameters for gauging emergency care capacity. The fact that this is true and that it was developed by the African Federation for Emergency Medicine (Emergency Care Assessment Tool) much later shows that the continent is not capable of finding out suitability of Emergency care. Best emergency care is not replicated properly in Africa as it is in developed countries with scenarios of inadequate training lack of or few specialists in the field. Health awareness in the continent has been improving and it seeks to unify mental, physical and social welfare for members of the community. For instance, it would be quite important for local governments to know that approach taken has shifted to elimination from control. It is reported that APOC had projected 80% elimination target by 2025, in hyperendemic and endemic regions of Sub-Sahara but later decried this objective; citing low funding and poor strategies employed (3).

Strategies that have been implemented and their effectiveness

Onchoncerias control program(OCP) and the African Program for Onchocerciasis Control( APOC) have been proposed and implemented to assist in combating this deadly disease. In 1972, after observing the kind of devastation caused by the river blindness in children and adults leading to blindness, the World Bank president intervenes into the matter and consequently spearheaded an international collaboration to combat the disease. He committed his own institution to take charge of catalytic financing. Onchocerciasis Control Program (OCP) was established under the control of the World Bank, WHO, United Nation Development Program (UNDDP), and the Food and Agriculture Organization (FAO) (10). Donor and financing support was then mobilized via World Bank from various private foundations, donor countries and multilateral institutions. This is the largest ever implemented strategy by the World Bank to help in managing and eliminating this deadly disease. The primary objective of this program was to use the vector control in interacting the transmission of onchocerciasis. A detailed Onchocerciasis prevalence epidemiological mapping and mapping of the remote reverse of 12000 miles these efforts. A substantial budget for research operation was rolled into the program to divert the problems and challenges and as well as investigating effective treatment and prevention options. This program was expected to run for 20 years. During this period, a number of the initial donors supported the program for 28 years. OCP's program has projected a remarkable achievement towards controlling river blindness in Sub-Saharan Africa. At the start of the program, about 30 million inhabitants in all areas covered by the program were infected (9). 100000 individuals of this number were blind. Currently, the spreading of the disease has been halted virtually. Notably, the 1.5 persons who were afflicted by the disease no longer experience any symptom. An estimated number of 50 thousand blind people have been combated and 20 million children born in the regions since the inception of the program are free from the risk of the disease. While OCP provided a wider range of success in controlling onchocerciasis, the disease still remains to be endemic in areas not covered by the OCP. Controlling disease was organizationally and technically intricate due to aerial spraying which was the only available option at the time (3). Mectizan Donation program. Merck and Co put in place various opportunities for controlling river blindness. In 1998, Merck decided to expand the mandate of the program to include the elimination of the lymphatic filariasis through the albendazole and Mectizan co-administration in all sub-Saharan African countries where onchocerciasis is co-endemic. Recently, more than 60milion treatment has been approved for river blindness (10). Sightsavers is expected to continue with the broader partnership to champion for the generous donation. Clinical trial supported by WHO and Mectizan denoted that the disabling symptoms of the river blindness could be averted just by one dose and this could translate to the death of 95 per cent of the tiny killer worms. The challenging part of this drug was the fact that it was difficult to be reached out by many developing Sub-Saharan countries where river blindness is endemic. Additionally, the resources provided by the donor communities failed to cater for the extra cost of the drug, which would then pose a double costs of the program. The Mectizan expert committee was formed to set and implement the rules on ways the drug would be delivered and the manner in which it would reach people. The committee came up with an annual process of application, a channel through which request for the drug would be granted. Notably, Mectizan Donation program by far superseded it initial projected goal of 6 million treatment to be achieved in 6 years. The program has rolled more than 400 million annual treatment since its inception. It is important to note that Mectizan was ranked as the highest-selling animal product in 1984 (5). A number of economic offsets significantly contributed to the feasibility of this program. For instance, the tax benefit that cut down the program cost.

Current strategies

TNT strategies: This is a strategy that needs a diagnosis for the infection and contraindication before the final decision is made concerning who to be treated using the made regimen. The primary objective of the TNT program is to diagnose a person who requires treatment and should be excluded from a given treatment due to an adverse reaction or rather no need for treatment. This has enhanced confidence in treatment that are pertinent and beneficial among the asymptomatic individuals. It has also resulted in safety treatment specifically in regions with severe adverse events. A rigorous mobilization is necessary to enhance the involvement of the whole community during the TNT strategy campaign (11).

ATSs: It entails an enhanced CDTI, complementary vector control, Test-and-Treat strategy, CDT with new drugs and drug combinations. All ATSs needs substantially more financial and human resources as well as commitment and determination at all health system level. By 2025 it expected that ATS will help in achieving the goal of the complete elimination of river blindness.

Complementary vector control: Some areas of OCP and the SIZs combined ivermetctin and vector control distribution. According to the data released by the Guinea, it was suggested that the distribution of the ivermectin would allow for the reduction of larviciding without a negative effect shown on the progress towards the elimination of river blindness. Notably, this combined strategy has equally been applied in Uganda in isolated foci. Considering the costs, ATS larvuciding is not a realistic vector elimination. Notably, addition of larvividing the season of peak transmission to treat ivermetctin could greatly reduce the rate of biting (5).

Enhanced CDTI: Research shows that ivermectin treatment effect every 3 or 6 months more regular treatment contains a greater effect on longevity and larvae reproductive capacity as compared to the annual treatment. Additionally, more regular treatment cut down on the level of skin microfilariae there by resulting in less transmission. This strategy has greatly resulted to the elimination of river blindness largely in American foci. Notably, some countries in Africa have introduced the strategy in selected areas for different programmatic reasons. It important to note that biannual treatment strategy was first launched in 2006. In 2007, Uganda resolved to the treatment of biannual in areas where simulius neavei was not viable. CDTI biannual has equally been applied since 2012 together with vector control to focus on the greater northern in order to eliminate the nodding syndrome linked with river blindness. According to Cheke (2017), biannual CDTI can assist in driving progress towards the elimination in areas where annual CDTI cannot.

The determinants of the success

Effective long-Term collaboration. Regional partnership is one of the major determinants that has led to the remarkable achievement towards the elimination of river blindness. It is based on comparative advantage. This is combined with the empowerment of the community. The long-term partnership has been proven to be an ideal model. Partners’ roles transparent delineation in a memorandum of agreement has reduced turf battles, instil trust among partners and maximized on effectiveness. In order to keep the commitment of the partners as well as sustaining large coalition for longer periods, communication has been activated and sharing of credit liberally has been championed (14). A detailed regional approach. Considering the natural history of the river blindness that has been characterized by blackfly vectors movement across the national borders, a detailed approach has been important. All the involved African countries have been effectively involved in contributing to the common objective hoping that they would all benefit from the outcome and any burden that may arise would be shared equally. Constant deliberation among countries has piled pressure on nations and their professional staff to put efforts into delivering results. The use of a well-schemed exit strategy and detailed approach have significantly contributed to in reassuring donors that the integrated effort would bear fruits (10). Africanisation and Capacity building. APOC and OCP programs have made significant efforts in strengthening technical capacity and African management. In the early 1970s, 70 per cent of OCP about 30 per cent were expatriate. Currently, 99 per cent of Africa the technical team are expatriates. More than 100 thousand community distributors have undergone extensive training and since the launch of APOC in 1995. Importantly, more than 500 former staff have gone back to their native countries coming back with advanced degrees, logistical, scientific and technical capacity needed to retain the program gains. Grassroots empowerment and Community participation. CDT has been integral in driving the program's objective of eliminating the disease as a health problem in Africa. The communities resolved to strategies that would then ensure Mectizan treatment is fully complied with as well as choosing trusted distributors (5). This type of system is cost-effective following the practice of compensating distributors with food as well as the donated drugs. Both cost-effectiveness and ownership have boosted the hopes that the network of Mectizan treatment will be sustained for a very long. Additionally, the community distributors system has addressed the dearth of skilled staff in rural and remote areas where river blindness is majorly a threat.

Conclusion

As evident above, great efforts have been made over the last decades in the fight against the river blindness in order to eradicate and completely eliminate it in Africa. Implemented strategies employed in the elimination of the disease have widely achieved their objectives in a significant number of countries. This has provided hope for the currently projected target to completely eliminate the disease in Africa by 2025. However, there are various problems and challenges that derailing the progress to eliminate the disease in Africa. For instance civil unrest and conflict, financial and technical challenges, ivermectin resistance emergence, transmission zones incomplete mapping loiasis and onchocerciasis co-endemicity among others. It is therefore essential that the effect of such challenges should be identified in all proposed and implemented strategies and necessary measures and mechanism to be put in place to drive the acceleration and progress of the elimination.

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