Guest blog by Gemma Ortiz, Neglected Diseases Senior Advocacy and Liaison Officer, Médecins Sans Frontières (MSF), Barcelona, Spain
Over 1 billion people, about one-sixth of the world’s population, are infected with one or more neglected tropical diseases (NTDs). These parasitic diseases are the most common infections in the 2.7 billion people living on less than $2 a day, afflicting populations who live in remote, rural areas, urban slums, or conflict zones and are often marginalized or forgotten by governments and the rest of the world.
Of the 14 NTDs identified by the World Health Organization (WHO), 4 are specifically highlighted as being the most neglected and requiring “innovative and intensified disease management” (IDM): sleeping sickness, Chagas disease, leishmaniasis, and Buruli ulcer. Except for Buruli ulcer, these IDM diseases have the highest fatality rates of all NTDs.
These IDM NTDs are particularly challenging to control due to poorly understood disease burdens, difficult and costly management (diagnosis, treatment, follow-up), inadequate R&D investment, and affected populations who often live in remote or insecure areas. Despite these challenges, MSF has been able to diagnose and provide life-saving treatment for those infected with these NTDs over the past 10-20 years, and continue to prioritize these populations.
Human African trypanosomiasis (HAT, or sleeping sickness) has been treated by MSF since 1986, with more than 48,000 patients treated to date in 7 countries in sub-Saharan Africa, where 99% of cases occur. MSF helped develop an improved treatment option, nifurtimox-eflornithine combination therapy (NECT), which is now being rolled out in endemic countries. However, current diagnostic algorithms need to be simplified; a new biomarker that allows diagnosis and staging of HAT using whole blood or serum, removing the need for a painful lumbar puncture, is urgently needed. More R&D and investment are needed to improve treatment (without injections) and ensure it is affordable, effective in both stages of the disease, and easy to use in remote, primary health posts close to the patients.
Patients with HAT also often live in areas of violent conflict, making it difficult to access care. For example, in a HAT program in the Democratic Republic of Congo, MSF was forced to halt activities in March 2009 due to insecurity; HAT treatment was only able to resume in January 2010.
Chagas disease (American trypanosomiasis) primarily afflicts populations throughout Latin America, where MSF has diagnosed and treated patients over the last decade. To date, we have tested more than 60,000 people and treated over 3,000. A barrier to patients not being treated is the lack of screening, leading to underreported numbers of cases. Two drugs are currently available to treat Chagas, benznidazole and nifurtimox, but few treatment programs exist, especially in rural and periurban areas, where ironically the burden of disease is higher due to the transmission cycle of the parasite. Both available drugs were developed in the 1960s for other indications and are associated with adverse events that can hinder treatment compliance. Safer, more effective medicines are needed, as is a test for cure.
The proposed Chagas Resolution from the WHO Executive Meeting in 2009 will finally be presented, discussed, and hopefully approved at the World Health Assembly in May this year.
Visceral leishmaniasis (VL, or kala azar) is the second-deadliest parasitic disease after malaria. VL is troublesome for similar reasons as the above trypanosomal NTDs, but with the compounded medical challenges of HIV co-infection, propensity for epidemic spread, and high endemicity in Africa, Asia, and Latin America. Over the past 20 years, we have treated more than 95,000 patients for VL, and have validated and introduced a rapid diagnostic test (rK39 antigen-based dipstick) that can be used in the field (ie, testing of patients possible in any context, without depending on the existence of health care or laboratory structures). In Bihar, India, one of the poorest states in the world, we have treated more than 4,000 patients with liposomal amphotericin B (AmBisome) since 2007; this treatment is simpler than conventional amphotericin B. However, drug costs of AmBisome and other VL drugs, such as sodium stibogluconate (SSG), are a key barrier to patients receiving treatment.
With the release of the proposed US federal budget for fiscal year 2011, global health has received attention, including NTDs. The largest proportional increase in the US global health budget went to NTDs: 138.5% increase from $65 million in 2010 to $155 million in 2011. Although this is welcome news, none of deadliest NTDs—HAT, Chagas, or VL—are included among these NTDs, nor is emphasis placed on R&D. This glaring omission of the most fatal NTDs is something MSF is addressing today (February 22) at a US Congressional Briefing in Washington DC, alongside the Drugs for Neglected Diseases initiative (DNDi) and RTI International. We hope this will bring more action on NTDs by both US and international policymakers and researchers. The US approach to NTDs needs to be comprehensive and include increased patient access to diagnosis and treatment for HAT, Chagas, VL, and Buruli. This must be coupled with increased R&D for new, more effective, field-adapted drugs and diagnostic tools. There is a clear opportunity to break the cycle of neglect and save lives.