Past Japanese successes show the way to accomplish future goals

School-based approach for parasitic disease control in Japan and Africa

Japan has achieved significant improvements in the control and prevention of parasitic infections through a school-based approach since the 1930s. The use of chemical fertilizers in agriculture, safe water and food, and improved sanitation and hygiene also contributed to the near eradication of endemic parasites. However, parasite infections continued to affect children mostly in resource-limited countries. The African continent has one of the highest burdens of such infections. The application of school-based approaches has several advantages where the structure of health-care systems is not optimal. In Africa, soil-transmitted helminths and schistosomiasis are frequently targets for school-based public health intervention. Mass drug administration by teachers at school can reach targeted children effectively and safely. The limitations of this approach include missing unattended children and absentee of teachers. Initially, mass drug administration at school for parasitic infections was thought to improve health and even socioeconomic status of children in the community. However, more recently the socioeconomic impact has been questioned although the reduction of parasitic diseases is still apparent. Moreover, other basic public health measurements such as increased toilet use, assuring safe water access and avoiding the use of human excrement as an agricultural fertilizer, are equally important for control and prevention of parasitic diseases. Further global efforts should be continued to achieve equal health for every child in a sustainable way.

Review of the Urinary Schistosomiasis Control in Morocco (1960-2018)

The purpose of this study is to describe the epidemiological profile and evolution of urinary schistosomiasis in Morocco, from the first confirmed case in 1960 until disease elimination, and control snails. During this period, 129,526 cases were recorded in Morocco. A majority of cases were reported in Agadir province (25%), Errachidia (18%), and Beni Mellal (13%). Other cases have been reported in the other provinces. Activities within the National Schistosomiasis Control Programme for more than three decades were focused in priori on screening in schools located in high-risk communities, treatment program, surveillance of snails in water bodies, and mollusciciding. Then, the goal of eliminating the transmission of schistosomiasis has been reached in 2004. Sixteen years later, no indigenous cases were detected in Morocco, and only 25 residual cases (resulting from bilharziasis previously treated) are detected, such as in Tata ( 40%), Errachidia (16%), and (12%) in Marrackesh. Similarly, recent national studies conducted on children and the snail reservoir hosts have indicated that no human and molluscs are currently infected with Schistosoma haematobium. Actually, timely investigation and management of imported cases has been implemented to prevent the reintroduction of the disease. The Ministry of Health is planning to implement final confirmatory surveys before requesting WHO to proceed with the formal verification process.

Soil-transmitted helminth infections and taeniasis on Samosir Island, Indonesia

Soil-transmitted helminth (STH) infections are important causes of morbidity in poorer areas of developing countries, with high endemicity in Southeast Asia. Humans are most often exposed to the infective forms of STHs in areas with sub-standard sanitation. The number of STH infections globally was estimated at 1.5 billion in 2018. In Indonesia, the prevalence of STH infections ranges from 2.5% to 62.0%. STH and taeniasis infections were evaluated on Samosir Island, North Sumatra, Indonesia. Field surveys were conducted in January 2003, February 2005, and February 2006 in Simanindo Subdistrict, with a subsequent survey conducted in the subdistricts of Simanindo and Ronggurnihuta in September 2015. A total of 371 individuals were screened between 2003 and 2006 and 368 were screened in 2015 (314 from Simanindo and 54 from Ronggurnihuta). Fecal samples were collected and examined microscopically by the Kato-Katz technique. The prevalence of STH infections in Simanindo for the years 2003, 2005, 2006, and 2015 was 41.4%, 52.2%, 55.7%, and 46.8%, respectively. The 2015 prevalence of STH infections in Ronggurnihuta was 66.7%. Taenia asiatica taeniasis prevalence was 3.4% and 2.2% for the years 2003 and 2005, respectively, with no cases detected in 2006 or 2015. The prevalence of STH infections in Simanindo and Ronggurnihuta was similar to other STH prevalence values reported for Indonesia. Country-level values have not changed substantially from those reported in the 1980s and 1990s, where prevalence ranged from 40% to 70%. Improvement of personal hygiene and environmental sanitation for control of STH infections on Samosir Island will require collaboration among multiple sectors.

Lessons from the Field Count more than Ever: The New Era of Global Health

For many years, Japan has been silent on the achievements of Japan’s Overseas Development Assistance program including the health improvement of foreign countries. Japan’s contribution to global health communities through G8 process including Hashimoto Initiative is steadfast. On the other hand, in the field activity level, experts involved in ODA have not disclosed their achievements. However, the article by Wada et al., which describes the contents of TEN MR (Minimum Requirement), shed light on Japan’s silent ODA community by disclosing Japan’s achievements in global health by drawing lessons that may be applicable to other countries. Our future challenge in the global health will be how to synthesize actions that reflect the lessons learnt from the field and which show scientific evidence using established methods.

Time to set the agenda for schistosomiasis elimination

It is time to raise global awareness to the possibility of schistosomiasis elimination and to support endemic countries in their quest to determine the most appropriate approaches to eliminate this persistent and debilitating disease. The main interventions for schistosomiasis control are reviewed, including preventive chemotherapy using praziquantel, snail control, sanitation, safe water supplies, and behaviour change strategies supported by information, education and communication (IEC) materials. Differences in the biology and transmission of the three main Schistosoma species (i.e. Schistosoma haematobium, S. mansoni and S. japonicum), which impact on control interventions, are considered. Sensitive diagnostic procedures to ensure adequate surveillance in areas attaining low endemicity are required. The importance of capacity building is highlighted. To achieve elimination, an intersectoral approach is necessary, with advocacy and action from local communities and the health community to foster cooperative ventures with engineers, the private sector, governments and non-governmental organizations specialized in water supply and sanitation. Examples of successful schistosomiasis control programmes are reviewed to highlight what has been learnt in terms of strategy for control and elimination. These include St. Lucia and other Caribbean islands, Brazil and Venezuela for S. mansoni; Saudi Arabia and Egypt for both S. mansoni and S. haematobium; Morocco, Tunisia, Algeria, Mauritius and the Islamic Republic of Iran for S. haematobium; Japan and the People's Republic of China for S. japonicum. Additional targets for elimination or even eradication could be the two minor human schistosome species S. guineenisis and S. intercalatum, which have a restricted distribution in West and Central Africa. The examples show that elimination of schistosomiasis is an achievable and desirable goal requiring full integration of preventive chemotherapy with the tools of transmission control. An agenda for the elimination of schistosomiasis would aim to identify the gaps in knowledge, and define the tools, strategies and guidelines that will help national control programmes move towards elimination, including an internationally accepted mechanism that allows verification/confirmation of elimination.

Major trends in human parasitic diseases in China

Tremendous progress has been made in the control and prevention of human parasitic diseases in mainland China in the past 30 years because of China's Reform and Opening to the Outside Policies initiated in 1978. However, parasitic diseases remain a major human health problem, with significant morbidity and mortality as well as adverse socioeconomic consequences. Although soil-transmitted parasitic diseases are in the process of being gradually controlled, food-borne parasitic diseases and emerging parasitic diseases are becoming the focus of new campaigns for control and prevention. This article reviews major trends in human parasitic diseases in mainland China, with perspectives for control.