Tropical Health Matters

Anthony AHUMIBE is a staff member of Nigeria CDC and presently a doctoral student at the Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan. Herein he examines the challenges posed by Lassa Fever to the West African region.

Following the West Africa Ebola epidemic of 2014, the global community has been preoccupied with Lassa fever, a zoonotic viral infection that has caused sickness and death in some communities in Nigeria, Liberia, Sierra Leone, and Guinea. Familiar challenges like absence of vaccine and point of care diagnostics are being handled through investments in research and development. There are, however, some imperceptible yet weighty challenges along the path of Lassa fever control.

The recent finding by Happi and colleagues shows that several species of household rodents, nonspecific to the familiar multimammate rats and other peri-urban small animals carry the Lassa virus and demonstrate that the virus is adapting. Conversely the economic turn of events in the endemic countries indicates that more people are moving into poverty and are unable to make proper hygiene choices. Furthermore, the expansion of city slums, and poor structured housing increases the opportunity for human contact with these rodents, thereby increasing rodents to human virus transmission.

The table derives from weekly reports published by NCDC. Nigeria Lassa fever data summary for Epi week 15, 2024 is compared with Epi Week 15 cumulative data in 2023 and 2024 (Courtesy: Nigeria CDC Situation report).

Related to the issue of homestead hygiene is the ineffective management of hospital waste in most of these communities. Many cases of Lassa fever slip through the cracks as malaria fever in health centres with limited capacity for molecular diagnosis.  After treatment, body fluid-stained dressings and disposables as well as serum and other body fluids are disposed as waste. The ineffectual medical waste management, so unsupervised, promotes fomite-rodent transmission and genetic spill-over to other species of household animals.

Citizens in the endemic countries share the same burden of poor health infrastructure and limited access to healthcare. For instance, only about 3% of adults aged 15-49 years have a form of health insurance. The high out-of-pocket expenditure required has caused increased hesitance in visiting hospital. As an alternative, many persons become victims of charlatans while genuine traditional healers who approach medical care blindly and without protective equipment become targets of infection and sources of transmission.

The photo (by author) shows the traditional sun drying of grated cassava for fufu meal. This exposure increases potential for Lassa fever transmission through contamination with rodent excreta.

The large trust deficit between the citizens and the political leaders owing to the several years of perceived economic and social mismanagement is also a great source of concern. Trust in the system by the people has been affirmed as necessary in advancing the cause of public health. Marcia McNutt and Michael Crow wrote in their op-ed, published in Issues in Science and Technology magazine that scientists and elected leaders need to earn citizens’ trust to win the war against misinformation and disinformation. Hesitancy in uptake of available countermeasures, appropriate risk perception and required behavioural change, seem imperiled in these communities due to the lack of trust in government and government institutions.

Finally, it is often assumed that every new infection cycle is initiated by human contact with rodent or rodent fluid. This does not consider however that the reinfection cycle could have started from a lab leak. Pathogen escape pathways are preponderant with many vials of remnant serum held unaccounted for in many public and private care institutions, some in community hospitals. This can only change if these countries develop a national system for accountability and repository of high-consequence pathogens.

The United States has been assisting in the fight against malaria and tropical diseases throughout the tropics. The question now arises is it ready to tackle these diseases on the home front?

In recent months CBS News reported that “Malaria cases in Florida and Texas are first locally acquired infections in U.S. in 20 years,” according to CDC. Local transmission of these 8 cases is the key concern because there are always imported cases from travelers to malaria endemic areas throughout the year. This has led to better planning of mosquito control activities. All of the Florida cases were found in Sarasota County. Although Anopheles mosquitoes still existed in the environment, they had not been infected in recent years.

Likewise Pensacola News Journal noted that, “Rising evidence is pointing to the possibility that leprosy has become endemic in the southeastern U.S. with Florida being named among the top reported states.” The paper explains that these Leprosy cases in central Florida account for nearly 20% of the national total, and that the state is considering instituting contact tracing.

Chagas disease may affect up to 300,000 people from Florida across to California, but an Emerging Pathogens Institute report shared in the Apopka Voice, explained that most cases remain undetected. While Chagas primarily affects people who have immigrated from Latin America, researchers are discovering locally acquired cases because the vector, the kissing bug, has been found in 29 states, and thus local transmission now occurs.

An article in PLoS NTDs explains that Zika, Dengue, and Chikungunya viruses are spread in the southern and Gulf Coast states by members of the Aedes mosquito family, aided by changes in weather and climate patterns. Just as in other countries where NTDs are endemic, the US experience of these diseases also sees that, “poverty equates to substandard housing that exposes residents to insect vectors, a lack of access to sanitation and water, and degraded environments.”

Local, State and National health agencies in the US are starting to awaken to the fact that diseases which we thought were eliminated back in the mid-19^th-century are making a comeback. At a minimum, funding and training are needed to equip our Health Departments with environmentally appropriate vector control measures, appropriate treatment regimens, and disease surveillance tools to tackle the same problems that are threatening the lives of people throughout low- and middle-income countries throughout the world.

The concept and goal of eliminating a disease appears simple on the surface, but complications ensue when the words “as a public health problem” are added.  We know that the distinction exists between eradication and elimination with the former being globally and the latter being nationally or regionally. The sum total action of eliminating a disease from all endemic countries therefore results in total global eradication.

The challenge comes when we try to qualify the concept of elimination. The US CDC defined elimination of disease as, “Reduction to zero of the incidence of a specified disease in a defined geographical area as a result of deliberate efforts; continued intervention measures are required.” Thus, there is no more transmission.  Following from this eradication is defined as, “Permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts; intervention measures are no longer needed.” Penn Medicine summarized this as, “Elimination means stopping the transmission of a disease in a specific geographic area or country, but not worldwide. Elimination is a crucial step in the path toward eradication, requiring constant monitoring and interventions to keep serious diseases at bay.”

The foregoing definitions seem straightforward, but what does elimination as a public health problem or a disease of public health concern mean? The World Health Organization recently “congratulate(d) Benin and Mali for eliminating trachoma as a public health problem. Concerning another neglected tropical disease (NTD), lymphatic filariasis (LF), global control programs are aiming “to reduce the prevalence of infection below target thresholds and to alleviate the suffering of people affected by lymphoedema and hydrocele.” Wiegand and colleagues in The Lancet Global Health note that, “For schistosomiasis, the criterion for elimination as a public health problem (EPHP) is defined as less than 1% prevalence of heavy-intensity infections (ie, ?50 Schistosoma haematobium eggs per 10 mL of urine or ?400 Schistosoma mansoni eggs per g of stool).” They take issue with the fact that such definitions mean that morbidity still exists, though at very levels, so elimination of transmission has not really occurred for any of these NTDs.

Because the social, environmental, and behavioral conditions that favor transmission may still exists, one cannot guarantee that incidence such diseases may not increase again. All three diseases, LF, Schistosomiasis, and Trachoma have been tackled primarily through preventive chemotherapy, is simply put, using mass drug administration (MDA) over a period of years until active surveillance determines that “infection (is) below target thresholds.” Trachoma does have its SAFE strategy which includes water, sanitation and hygiene interventions, but drugs can reduce the disease without long term achievements in such activities have become sustainable.

Prada et al. in the Journal of Infectious Diseases warn that there can be resurgence of a disease that was documented to be eliminated as a public health problem. They explain that the transmission assessment survey held after several MDA rounds for LF may not be enough to guarantee that low levels of transmission and eventual elimination are achieved. They conclude that, “The risk of resurgence after achieving current targets is low and is hard to predict using just current prevalence. Although resurgence is often quick (<5 years), it can still occur outside of the currently recommended post-intervention surveillance period of 4–6 years,” and recommend monitoring beyond this period.

Toor and co-researchers suggest for NTD programs that, “as case numbers drop and elimination comes into prospect, transmission reduction through other interventions, such as vector control and sanitation, becomes crucial in reducing the probability and speed of resurgence, particularly when MDA or screening programs are halted. Surveillance activities for detecting elimination and resurgence become increasingly important to ensure that successes are maintained.”

Ultimately, unless the context of NTD transmission is addressed, elimination will be an elusive goal. Therefore, as WHO advocated on the recent World NTD Day, “Everybody, including leaders and communities, to confront the inequalities that drive NTDs and to make bold, sustainable investments to free the world’s most vulnerable communities affected by NTDs from a vicious cycle of disease and poverty.”

A May 28^th press release from the World Health Organization states that, “Togo eliminates trachoma as a public health problem.” The article explains that …

“Validation of trachoma elimination as a public health problem in Togo was based on evidence. Several population-based trachoma surveys were conducted starting from 2006 to 2017. The 2017 survey using WHO recommended methodology found that the prevalence of key indicators was below the WHO trachoma elimination threshold. There was also evidence that Togo’s health system is able to identify and treat new cases of late complications of trachoma.”

This raises the question, is Trachoma gone from Togo or does trachoma continue to exist at some low level whereby, as WHO notes, Togo has joined, “12 other countries that have been validated by WHO for having eliminated trachoma as a public health problem.”

This description of disease elimination contrasts sharply with the global concerns when “health authorities in Malawi have declared an outbreak of wild poliovirus type 1 after a case was detected in a young child in the capital Lilongwe. This is the first case of wild poliovirus in Africa in more than five years.” Wild polio virus had been declared eliminated in Africa, and just one case in one country grabs international attention.

Would one case of trachoma tomorrow receive the same concern in Togo? Apparently not according to the WHO definition, “Elimination of trachoma as a public health problem is defined as: (i) a prevalence of trachomatous trichiasis (TT) “unknown to the health system” of < 1 case per 1000 total population; and (ii) a prevalence of trachomatous inflammation-follicular (TF) in children aged 1–9 years of < 5%, in each formerly endemic district.”

So, while no cases of smallpox, guinea worm or polio would be tolerated after elimination has been declared, parents of a child who develops trachoma in Togo tomorrow would be told that your child’s case is only 1 in a 1000 and not of concern to public health. The caveat is though that “the health system (must be) able to identify and manage incident TT cases.” Presumably, if such management capacity does not exist, the disease in question could spread and elimination would be eliminated.

Another Neglected Tropical Disease, Lymphatic Filariasis, faces the same challenge in terms of elimination status. WHO explained in its guidance that, “In 1997, the 50th World Health Assembly resolved to eliminate LF as a public-health problem (resolution WHA50.29). In response, WHO proposed a comprehensive strategy for achieving the elimination goal that included interrupting transmission in endemic communities and implementing interventions to prevent and manage LF-associated disabilities The LF guidance stresses “Effective monitoring, epidemiological assessment and evaluation are necessary to achieve the aim of interrupting LF transmission,” or in a word Surveillance. There is clear concern for “absence of transmission” and worries about “recrudescence.”

While polio has a vaccine and guinea worm relies on providing safe community water, LF and Trachoma elimination depends on mass drug administration (MDA) at planned intervals until such time as transmission is reduced. All require a strong health system to implement, but the challenges of maintaining MDAs until such time as elimination has been validated is somewhat more challenging. In this context the communication is extremely important. Just because WHO validates the elimination of a disease as a public health problem, does not give policy makers license to ignore that disease. Advocacy is continually needed such that even after apparent elimination, neglected diseases will not be forgotten and health systems themselves not neglected.

A variety of malaria and related issues have arisen over the past two days. A media coalition for malaria elimination formed in Ghana. A Nigerian NGO stresses the importance of addressing malaria on Nigeria’s 60th Independence Day (October 1). An innovative technology foundation is supporting various malaria and NTD treatment and diagnostic research efforts. Click on links below to read the details.

Media Coalition for malaria control and elimination launched

A Media Coalition comprising of selected journalists and editors, has been launched in Ghana under the umbrella of the “Zero Malaria Starts with Me” campaign to eliminate malaria by 2030. The Coalition, which aimed to enhance the quality and quantity of malaria coverage, and support broader advocacy efforts, was launched at a workshop in Accra organized by the National Malaria Control Programme (NMCP), in collaboration with the African Media and Malaria Research Network and Speak Up Africa, an advocacy and communication Organisation based in Senegal.

The workshop brought together media personnel from across the regions, who nominated their Regional Executives, with two National Co-Chairpersons coming from Greater Accra. The Members of the Coalition, made a firm declaration of their commitment towards the elimination of malaria in Ghana by the year 2030, by championing the fight, taking responsibility for their roles through proactive, regular, accurate, and high-quality media output of news on malaria.

Chinwe Chibuike Foundation Set To Flag-off Full Scale Malaria Eradication Program On Independence Day

A Nigeria indigenous and international non-governmental organization, envisioned to create a conducive environment towards the accessibility of healthcare facilities and improved educational opportunities, has joined the fight against the bizzare challenges of Malaria. The renowned Nigeria-USA humanitarian organization, Chinwe Chibuike Foundation is collaborating with other organizations to flagoff a full scale malaria eradication exercise tagged “Nigeria at 60 Malaria Eradication Project”, on the 1st of October 2020.

According to the founder and President of Chinwe Chibuike Foundation, Ms Gloria Chibuike, during an interview session with Pulse TV few days ago, she noted the forthcoming Nigeria At 60 Malaria Eradication Program will be different and of more impact, especially with the full scale approach and introduction a new Malaria repellant Band.

While emphasizing on the extensive features of the project, Ms Gloria described Malaria as one of the biggest problems in Africa at the moment, considering the increased number of recorded deaths and infection. She narrated that the discovery of the new malaria repellent band was timely and off-course very efficient, especially with testimonies from few persons who have already tried the brand.

Drugs and Diagnostics: Malaria and NTDs

The Global Health Innovative Technology (GHIT) Fund announced today a total of 1.37 billion yen (US$13 million*) to invest in seven partnerships to develop new lifesaving drugs and diagnostics for malaria, Buruli ulcer, Chagas disease, leishmaniasis, schistosomiasis, and soil-transmitted helminths (STH). This includes three newly funded projects and four that will receive continued funding. The RBM Partnership is planning on how to monitor and provide technical support for ITN programs. Click the links within each section to read details.

As of September 29, GHIT’s portfolio includes 50 ongoing projects: 26 discovery projects, 16 preclinical projects and eight clinical trials (Appendix 3). The total amount of investments since 2013 is 22.3 billion yen (US$211 million).

Support the Improvement of Operational Efficiency of ITN Campaigns

The Alliance for Malaria Prevention (AMP) is a workstream within the RBM Partnership to End Malaria. With malaria indicators stagnating and intense pressure to improve access and use of effective ITNs, WHO has renewed focus on stratifying vector control strategies in countries. Along with the introduction of new, more expensive ITNs, countries are now challenged to determine where they should deploy different ITN types to manage insecticide resistance within limited funding envelopes, as well as to identify more efficient ways to implement mass ITN distribution.

Countries that have accessed AMP technical assistance have significantly improved their capacity to modify and update strategies and tools to increase ITN access, use and accountability. They have also continued to identify further gaps and look for effective ways to address them. Now AMP planning to support update and finalization of ITN tracking tool, aligned with priorities across major partners (GF, PMI, RBM).

Malaria Journal released three articles ranging from the relation between malaria and agricultural irrigation, artemisinin resistance on the Myanmar-China border, and efforts at costing malaria elimination interventions. PLoS Medicine examined the quality of malaria clinical management in children. Finally, Frontiers in Cellular and Infection Microbiology reported on a new drug against malaria and toxoplasmosis. Click on links to read more details.

Minimal tillage and intermittent flooding farming systems show a potential reduction in the proliferation of Anopheles mosquito larvae in a rice field in Malanville, Northern Benin

Irrigation systems have been identified as one of the factors promoting malaria disease around agricultural farms in sub-Saharan Africa. However, if improved water management strategy is adopted during rice cultivation, it may help to reduce malaria cases among human population living around rice fields.

A clear reduction of larva density was observed with both intermittent flooding systems applied to minimal tillage (MT?+?IF?+?NL) and intermittent flooding applied to deep tillage (DT?+?IF?+?AL), showing that intermittent flooding could reduce the abundance of malaria vector in rice fields. Recommending intermittent flooding technology for rice cultivation may not only be useful for water management but could also be an intentional strategy to control mosquitoes vector-borne diseases around rice farms.

No evidence of amplified Plasmodium falciparum plasmepsin II gene copy number in an area with artemisinin-resistant malaria along the China–Myanmar border

The emergence and spread of artemisinin resistance in Plasmodium falciparum poses a threat to malaria eradication, including China’s plan to eliminate malaria by 2020. Piperaquine (PPQ) resistance has emerged in Cambodia, compromising an important partner drug that is widely used in China in the form of dihydroartemisinin (DHA)-PPQ. Several mutations in a P. falciparum gene encoding a kelch protein on chromosome 13 (k13) are associated with artemisinin resistance and have arisen spread in the Great Mekong subregion, including the China–Myanmar border. Multiple copies of the plasmepsin II/III (pm2/3) genes, located on chromosome 14, have been shown to be associated with PPQ resistance.

DHA-PPQ for uncomplicated P. falciparum infection still showed efficacy in an area with artemisinin-resistant malaria along the China–Myanmar border. There was no evidence to show PPQ resistance by clinical study and molecular markers survey. Continued monitoring of the parasite population using molecular markers will be important to track emergence and spread of resistance in this region.

Costing malaria interventions from pilots to elimination programmes

Malaria programmes in countries with low transmission levels require evidence to optimize deployment of current and new tools to reach elimination with limited resources. Recent pilots of elimination strategies in Ethiopia, Senegal, and Zambia produced evidence of their epidemiological impacts and costs. There is a need to generalize these findings to different epidemiological and health systems contexts. Drawing on experience of implementing partners, operational documents and costing studies from these pilots, reference scenarios were defined for rapid reporting (RR), reactive case detection (RACD), mass drug administration (MDA), and in-door residual spraying (IRS). These generalized interventions from their trial implementation to one typical of programmatic delivery. In doing so, resource use due to interventions was isolated from research activities and was related to the pilot setting. Costing models developed around this reference implementation, standardized the scope of resources costed, the valuation of resource use, and the setting in which interventions were evaluated. Sensitivity analyses were used to inform generalizability of the estimates and model assumptions.

Populated with local prices and resource use from the pilots, the models yielded an average annual economic cost per capita of $0.18 for RR, $0.75 for RACD, $4.28 for MDA (two rounds), and $1.79 for IRS (one round, 50% households). Intervention design and resource use at service delivery were key drivers of variation in costs of RR, MDA, and RACD. Scale was the most important parameter for IRS. Overall price level was a minor contributor, except for MDA where drugs accounted for 70% of the cost. The analyses showed that at implementation scales comparable to health facility catchment area, systematic correlations between model inputs characterizing implementation and setting produce large gradients in costs. Prospective costing models are powerful tools to explore resource and cost implications of policy alternatives. By formalizing translation of operational data into an estimate of intervention cost, these models provide the methodological infrastructure to strengthen capacity gap for economic evaluation in endemic countries. The value of this approach for decision-making is enhanced when primary cost data collection is designed to enable analysis of the efficiency of operational inputs in relation to features of the trial or the setting, thus facilitating transferability.

Quality of clinical management of children diagnosed with malaria: A cross-sectional assessment in 9 sub-Saharan African countries between 2007–2018

Appropriate clinical management of malaria in children is critical for preventing progression to severe disease and for reducing the continued high burden of malaria mortality. This study aimed to assess the quality of care provided to children under 5 diagnosed with malaria across 9 sub-Saharan African countries. We used data from the Service Provision Assessment (SPA) survey. SPAs are nationally representative facility surveys capturing quality of sick-child care, facility readiness, and provider and patient characteristics across 9 countries, including Uganda (2007), Rwanda (2007), Namibia (2009), Kenya (2010), Malawi (2013), Senegal (2013–2017), Ethiopia (2014), Tanzania (2015), and Democratic Republic of the Congo (2018).

In this study, we found that a majority of children diagnosed with malaria across the 9 surveyed sub-Saharan African countries did not receive recommended care. Clinical management is positively correlated with the stocking of essential commodities and is somewhat improved in more recent years, but important quality gaps remain in the countries studied. Continued reductions in malaria mortality will require a bigger push toward quality improvements in clinical care. Despite increases in the distribution of malaria tests and effective antimalarial medications, significant gaps in the quality of care for pediatric malaria are present in these 9 countries. Further improvements in quality of malaria care may require a better understanding of remaining barriers and facilitators to appropriate management.

Novel drug could be a powerful weapon in the fight against malaria and toxoplasmosis

Princeton researchers are making key contributions toward developing a promising new treatment for the widespread and devastating diseases toxoplasmosis and malaria.
The Princeton scientists specialize in preparing the drug compound into a medicine that is both safe and effective for humans and able to reach its intended sites of action in the body in sufficient doses. An international team of scientists found the new drug—designated JAG21—to be highly effective against parasites in cell-based studies in the lab. After the discovery, team representatives contacted Princeton’s Robert Prud’homme for help in translating the JAG21 compound into a deliverable medication. Prud’homme is a co-author of a study, published in June 2020 in Frontiers in Cellular and Infection Microbiology, that describes the compound and its excellent preliminary results in mice.

Today we share news and abstracts concerning detecting malaria in pregnancy, news about the opening remarks from the WHO Director General at a special malaria and COVID-19 webinar, resumption of NTD activities after COVID-19 restrictions reduced, and mapping of Ebola carrying bats whose territory overlaps malaria in Africa. Click on the links to read more.

Prevalence and clinical impact of malaria infections detected with a highly sensitive HRP2 rapid diagnostic test in Beninese pregnant women

While sub-microscopic malarial infections are frequent and potentially deleterious during pregnancy, routine molecular detection is still not feasible. This study aimed to assess the performance of a Histidine Rich Protein 2 (HRP2)-based ultrasensitive rapid diagnostic test (uRDT, Alere Malaria Ag Pf) for the detection of infections of low parasite density in pregnant women.

This study demonstrates the higher performance of uRDT, as compared to cRDTs, to detect low parasite density P. falciparum infections during pregnancy, particularly in the 1st trimester. uRDT allowed the detection of infections associated with maternal anaemia.

The distribution range of Ebola virus carriers in Africa may be larger than previously assumed

Since Ebola overlaps both symptomatically and geographically with malaria in Africa, it is “Worrying that science has hitherto underestimated the range of Ebola-transmitting bat and fruit bat species. In this case, the models would provide a more realistic picture,” explains Dr. Lisa Koch

Based on ecological niche modeling, his team was able to show that the respective bat and fruit bat species are able to thrive in West and East Africa, including large parts of Central Africa. A wide belt of potential habitats extends from Guinea, Sierra Leone, and Liberia in the west across the Central African Republic, the Republic of the Congo and the Democratic Republic of the Congo to Sudan and Uganda in the East. A few of the studied bats and fruit bats may even occur in the eastern part of South Africa.

WHO Director-General’s Opening Remarks At the Webinar – Responding to the Double Challenge of Malaria and Covid-19

The WHO Director General is encouraged by efforts to maintain malaria services despite the COVID-19 outbreak, but says, “I would like to recognize and applaud all these efforts, and to thank all of you who have worked so hard to preserve and maintain those services to the greatest degree possible. However, despite these actions, it breaks my heart to report that we still expect to see an increase in cases and deaths from malaria.

“In a recent WHO survey of 105 countries, 46% of countries reported disruptions in malaria diagnosis and treatment. These disruptions threaten to set us back even further in realizing our shared vision for a malaria-free world.”

NTD Disease treatments restart in Africa as COVID-19 restrictions ease

It is not just malaria services that have been disrupted by COVID-19 responses. Treatment programmes that will reach millions of Africans at risk from debilitating neglected tropical diseases (NTDs) have restarted in a significant step towards COVID-19 recovery. Around one million people in Jigawa state, Nigeria have received antibiotics to treat the blinding eye disease trachoma and stop it from spreading.

Nigeria is the first country that Sightsavers and partners has supported to resume work on NTDs, which can have a devastating impact on some of the poorest communities in the world, with other African countries due to follow soon. In April, the threat of COVID-19 led the World Health Organization to recommend suspending mass treatment campaigns, which treat and prevent these diseases, but it has since provided guidance on restarting activities safely.

As part of the activities in the course Social and Behavioral Foundations of Primary Health Care, class members write a blog on a current health issue. Amr Marawan has shared the context of schistosomiasis control in Nigeria on the class blog. His writing is reposted below and can also be read along with those of his classmates in the SBFPHC Blog site.

Schistosomiasis was described in papyrus papers thousands of years ago by ancient Egyptians. Then it was re-described by Theodore Bilharz, a pioneer parasitologist, 150 years ago in Cairo, Egypt. Schistosomiasis is among a group of neglected tropical diseases hitting sub-Saharan Africa. There are more than 25 million individuals infected and more than 100 million at risk in Nigeria. Among the different types of schistosomiasis, Schistosoma Haematobium affects the urogenital system causing blood in the urine and other symptoms and predisposes to urinary cancer.

photo source: http://www.bio.davidson.edu/people/midorcas/GISclass/GISwebsites/grayson/Schistosomiasis.htm

Despite the global efforts over the past 50 years, we only achieved limited success in Nigeria. Most of the campaigns designed used Praziquantel for prevention and treatment, as it has shown great success in multiple countries. Unlike other previously endemic states, the use of chemotherapy was not sufficient to address this major problem in Nigeria due to several limitations. In 2012. The World Health Organization (WHO) and World Health Assembly (WHA) adopted a multifaceted plan to eradicate schistosomiasis. The plan aims at strengthening the local health systems, using chemotherapy, appropriate sanitation, and water systems, as well as promoting hygiene education and snail control. There will be multiple designs for this approach to address the different challenges in the different states.

In order to succeed in this battle, all the stakeholders should cooperate and understand their role. The Federal ministry of health in Nigeria should communicate and supervise the local communities closely to ensure that there is no waste of resources. The pharmaceutical companies play a fundamental role by supplying millions of praziquantel pills with the help of non-governmental organizations (such as the Carter Center). The schools and religious leaders should educate the citizens about this disease and the role of both chemotherapy and sanitation to lead a healthy and productive life. The local community leaders are responsible for maintaining the momentum to achieve the utmost benefit for their people in spite of the conflicting perception for this campaign.

Six years after the WHA declaration, there was a substantial success demonstrated by treating approximately 75 % of school aged children. There is a new road map issued by the WHO for the tropical diseases for 2021-2030 to address the gaps and finish the incomplete mission.

If it were not difficult enough to guide global health during a pandemic, some world leaders are trying to deflect attention from the real dangers at hand to score on their petty political concerns. In the meantime, we need to focus on what tropical health and disease issues may actually be coming under consideration at the virtual WHA 73.

Agenda item 3 (A73/CONF./1 Rev.1) or “COVID-19 response Draft resolution” directly addresses the concerns of many that other major deadly diseases and essential services should not be further neglected. The large group of resolution proponents urge countries and organizations to,

“Maintain the continued functioning of the health system in all relevant aspects, in accordance with national context and priorities, necessary for an effective public health response to the COVID-19 pandemic and other ongoing epidemics, and the uninterrupted and safe provision of population and individual level services, for, among others, communicable diseases, including by undisrupted vaccination programmes, neglected tropical diseases, noncommunicable diseases, mental health, mother and child health and sexual and reproductive health and promote improved nutrition for women and children, recognizing in this regard the importance of increased domestic financing and development assistance where needed in the context of achieving UHC.”

In Provisional agenda item 23 (A73/32) “Progress reports by the Director-General” we find updates on guinea worm eradication and the burden of snakebite envenoming. The report notes the situation in 2019, which is a far cry from the millions of cases in the 1980d when the dracunculiasis eradication effort was launched. “In 2019, three countries reported a total of 53 human indigenous cases of dracunculiasis (guinea-worm disease), namely, Angola (one case), Chad (48 cases) and South Sudan (four cases), from a total of 28 villages. Cameroon reported one human case, probably imported from Chad.”

It is important to note that, “The global dracunculiasis eradication campaign is based on both community and country-focused interventions,” where community members play an important role in surveillance and notification. This includes at-risk and border areas, as is being done in Cameroon. The challenge of human Dracunculus medinensis infection in dogs continues and points to the importance of One Health in the control and elimination of NTDs. Surveillance is not cheap, and the report stresses that funds are still needed so that international partners can continue to ensure that the last case of guinea worm is detected and contained.

Moving from the smaller serpent to the larger variety, the report recalls the May 2018 World Health Assembly resolution WHA71.5 on addressing the burden of snakebite envenoming. A global strategy, “Snakebite envenoming: a strategy for prevention and control” was launched in  in May 2019. The WHO Secretariat has “fostered international efforts to improve the availability, accessibility and affordability of safe and effective antivenoms for all, through assessments of antivenom manufacturing, training programs and stockpile procedures.

Finally, provisional agenda item 11.8 (A73/8) addresses a “Draft road map for neglected tropical diseases 2021–2030.” This builds on resolution WHA66.12 (2013) on WHO’s earlier road map for accelerating work to overcome the global impact of neglected tropical diseases (2012–2020). The proposed interventions build on important principles including:

1. Tackling neglected tropical diseases through support of the vision of universal health coverage
2. Adopting grassroots approaches that enable access to some of the world’s poorest, hard-to reach communities and people affected by complex emergencies
3. Monitoring progress against neglected tropical diseases as a litmus test of progress towards the achievement of universal health coverage

The report notes that “40 countries, territories and areas have eliminated at least one neglected tropical disease,” most notably dracunculiasis (as mentioned above, lymphatic filariasis and trachoma. Although “substantive progress has been made since 2012, it is evident that not all of the 2020 targets will be met.” Hence, a new draft road map for neglected tropical diseases for 2021–2030 is required. The three pillars supporting the new roadmap are outlined in the attached figure.

It is good to know that the 73^rd World Health Assembly will not be completely overshadowed by COVID-19 and politics. Efforts to sustain and improve NTD control and elimination must not be jeopardized.

In the past week urban transmission in Goma, a city of at least 2 million inhabitants in eastern Democratic republic of Congo, was documented as a gold miner came home and infected his wife and child. To get a grip on the spread of the disease, DRC is considering another vaccine, not without some controversy. WHO provides detailed guidance on all aspects of response. On the malaria front we have learned more about malaria vectors, natural immunity and reactive case detection.

Ebola Challenges: Vaccines, Urban Transmission

The current Ebola vaccine being deployed to over 150,000 people in North Kivu and Ituri Provinces was itself an experimental intervention during 2016 when it was first used in the largest ever outbreak located in West Africa. BBC reports that, “World Health Organization (WHO) data show the Merck vaccine has a 97.5% efficacy rate for those who are immunised, compared to those who are not.”

The proposed addition of a Johnson and Johnson vaccine would be in that same experimental phase if introduced in DRC now. It has been proven safe as well as effective in other primates. The challenge is that even though the Merck vaccine supplies are near 500,000, this is not enough to cover the potential needs in an area with over 10 million people, although Merck is still producing more. At present, BBC says, “Those pushing for the use of the new Johnson & Johnson vaccine, had proposed using it to create a protective wall, vaccinating people outside the outbreak zone.” In addition, the new national response team is concerned that “Only about 50% of cases of Ebola in the Democratic Republic of Congo are being identified.”

Finally, there is the issue of community mistrust of government workers and challenging logistics. “There are also concerns that the new vaccine – which requires two injections 56 days apart – may be difficult to administer in a region where the population is highly mobile, and insecurity is rife.”

If efforts at vaccination are needed soon in Goma, up to 2 million doses might be needed. Reuters reports that, “Congolese authorities were racing to contain an Ebola epidemic on Thursday, after a gold miner with a large family contaminated several people in the east’s main city of Goma before dying of the hemorrhagic fever.” Readers may recall that the West Africa outbreak of 2014-16 in Guinea, Sierra Leone and Liberia accelerated greatly after infected people went to major cities in search of help.

The miner is the second ‘imported case into Goma, which borders Rwanda, but because his family lives there, he has already infected his wife and one of his 10 children. Contacts are being traced and monitored, but this urban and border threat is one of the factors that led WHO to finally declare the current outbreak a public health emergency.

Malaria

As we move toward malaria elimination Reactive Case Detection (RCD) has been proposed as an integral part of these efforts with the hopes that is can be conceived of as a way of gradually decreasing transmission, according to an article in Malaria Journal. In fact, the value of RCD may be limited as follows:

• RCD alone can eliminate malaria in only a very limited range of settings, where transmission potential is very low
• In other settings, it is likely to reduce disease burden and help maintain the disease-free state in the face of imported infections

Another article looks at “natural exposure to gametocytes that can result in the development of immunity against the gametocyte by the host as well as genetic diversity in the gametocyte.” The researchers learned that there can be variations in immune response depending on season and geography. This information is helpful in planning malaria elimination interventions.

On the vector front a baseline susceptibility testing was conducted in 16 countries in sub-Saharan Africa for neonicotinoids. “The target site of neonicotinoids represents a novel mode of action for vector control, meaning that cross-resistance through existing mechanisms is less likely.” The findings will help in the preparation for rollout of clothianidin formulations as part of national IRS rotation strategies by PMI and other partners.

Researchers also called on us to learn more about malaria vectors in other parts of the world. In order to eliminate Plasmodium falciparum from the Caribbean and Central America program planners should consider local vector characteristics such as An. albimanus. They found that, “House-screening and repellent IRS are potentially highly effective against An. albimanus if people are indoors during the evening.”

Vectors are also of concern on the edges of malaria transmission, particularly in South Africa, one of the ‘elimination eight’ countries of the Southern Africa Development Community. Researchers examined the, “potential role of Anopheles parensis and other Anopheles species in residual malaria transmission, using sentinel surveillance sites in the uMkhanyakude District of northern KwaZulu-Natal Province.” They found Anopheles parensis is a potential but minimal vector of malaria in South Africa “owing to its strong zoophilic tendency.” On the other hand, An. arabiensis was found to be the major vector responsible for residual malaria transmission in South Africa. Since these mosquitoes were found in outdoor-placed resting traps, interventions are needed to control outdoor-resting of vector populations.

NTDs of Concern

During the week, the member states of the African Union renewed their commitment to fight and permanently eliminate Neglected Tropical Diseases. Africa.com reported that, “Achievements to date include 1 billion people treated against at least one NTD and 37 countries have completed the removal of at least one NTD.”

Although some reports have discounted the idea of trachoma in Namibia, there may be reason to re-examine the situation. On Twitter Anthony Solomon notes that Namibia needs #trachoma prevalence surveys. A just-completed joint Ministry of Health & Social Services/@WHO mission found active trachoma & trichiasis in Zambezi & Kunene Regions.

The Times of India draws attention to snakebite. It says that “Under-reported and inadequately treated, fatalities in India are estimated at close to 50,000 a year, the world’s highest.”

Overall we can see that the concept of ‘neglect’ has several uses. There is neglect if half of Ebola cases are undetected. There is neglect if we do not understand malaria vectors in low transmission areas. Finally, there is neglect if we do not conduct up-to-date disease surveys to determine whether a disease is present or not. Elimination of tropical diseases is challenging when key processes are neglected.