Understanding Rare Diseases: Lessons for Nepal’s Public Health System

Rare diseases are often perceived as conditions that affect only a very small number of people. However, their importance goes far beyond numbers. They highlight gaps in diagnosis, treatment, health systems, and research capacity. In the United States, the Genetic and Rare Diseases (GARD) Information Center, a program of the National Institutes of Health (NIH), provides accessible and reliable information on rare diseases for patients, families, and healthcare professionals. GARD supports people living with rare diseases by offering simplified information on diagnosis, symptoms, care, and support resources.

In the United States, a disease is generally considered rare if it affects fewer than 200,000 people. Although each rare disease affects a relatively small population, the combined burden is substantial. Older NIH-linked estimates often cite more than 6,800 to 7,000 rare diseases affecting 25 to 30 million Americans. More recent GARD information notes that advances in disease classification and genetics may place the number at over 10,000 rare diseases. This shows that rare diseases are not a minor issue, but a significant public health challenge.

Why Are Rare Diseases Called “Rare”?

A disease is labeled rare because of its low prevalence within a specific population, not because it is unimportant or poorly understood. Many rare diseases are caused by changes in genes or chromosomes, which can affect disease development, severity, and inheritance patterns. At the same time, not all rare diseases are genetic. Some infectious and tropical diseases may be classified as rare in high-income countries like the United States simply because they affect very few people there, even if they remain major public health concerns elsewhere.

This distinction is especially important for countries like Nepal. A disease that is “rare” in the United States may still be common, neglected, or highly relevant in South Asia.

Tuberculosis in Nepal: Rare in the U.S., Common in Nepal

Tuberculosis (TB) is a strong example of how disease classification depends on setting. In the United States, TB may be relatively uncommon compared with many low- and middle-income countries. In Nepal, however, TB remains a major public health challenge.

Nepal conducted its first National Tuberculosis Prevalence Survey in 2018–19, which revealed a significantly higher TB burden than previously estimated. According to the survey:

• TB prevalence was estimated at 416 per 100,000 population
• Around 117,000 people were living with TB disease
• TB incidence was estimated at 245 per 100,000 population
• Approximately 69,000 new TB cases occurred in 2018
• TB mortality was found to be 3.1 times higher than previous estimates

These findings indicate that TB remains far from controlled in Nepal. With increasing transportation, migration, and public movement, infectious diseases such as TB continue to spread easily, particularly when diagnosis is delayed or treatment access is uneven. Active TB case detection, timely reporting, and treatment completion remain essential if Nepal is to reduce transmission and move toward TB elimination.

Other Diseases of Public Health Concern in Nepal

Tuberculosis is not the only example. Diseases such as malaria, dengue, rabies, and snakebite-related illness continue to pose serious challenges in Nepal. In some international databases or registries, such conditions may appear under rare or neglected disease listings because they are uncommon in certain countries. However, in Nepal, these conditions are not rare in practical public health terms. They remain important causes of illness, disability, and preventable death.

This difference reminds us that disease registries should be interpreted with caution. A label used in one country’s policy or information system may not reflect the real burden in another.

The Way Forward for Nepal

The concept of rare disease should not be understood as a sign of low importance. In some settings, it reflects successful disease control. In others, it reflects limited case numbers but not necessarily low impact. For Nepal, both infectious and genetic rare diseases require a stronger health system response.

1. Strengthen surveillance and disease registries

A national disease registry is critical for early diagnosis, case tracking, service planning, and policy development. Every identified case should be properly documented and linked to available care. Better registries would also help Nepal understand the true burden of both rare genetic disorders and neglected infectious diseases.

2. Expand early diagnosis and reporting

For infectious diseases, active surveillance, community-level screening, rapid notification, and public education are essential. Conditions like TB, malaria, dengue, and rabies can be better controlled when cases are identified early and responded to quickly.

3. Develop disease-specific public health programs

National policies must be tailored to local epidemiology. For example:

• Areas with high malaria burden should receive targeted vector control and case detection programs
• Rabies prevention requires vaccination campaigns, dog-bite awareness, and zoonotic disease control
• TB control needs stronger laboratory services, contact tracing, and uninterrupted treatment access

4. Invest in genetics and molecular research

Genetic rare diseases present a different challenge. Their diagnosis and management often require advanced laboratory facilities, molecular testing, and specialized expertise. Nepal currently faces limitations in these areas. Therefore, institutional collaboration, international partnerships, and investment in genomic and translational research are highly necessary.

5. Improve access to treatment and support

People living with rare diseases often need not only medical care, but also psychological, social, and family support, similar to the support model promoted by GARD. A patient-centered approach can improve quality of life even when curative treatment is not available.

Conclusion

Rare diseases are not rare in their overall impact. They represent an important intersection of medicine, genetics, public health, and health equity. While the United States defines a rare disease as one affecting fewer than 200,000 people, the relevance of any disease depends on context. Tuberculosis, malaria, dengue, rabies, and snakebite may be uncommon in some countries, but they remain major public health concerns in Nepal.

For Nepal, the path forward includes stronger registries, earlier diagnosis, better surveillance, targeted disease-control programs, and greater collaboration in genetic and molecular research. Recognizing and responding to disease burden in local context is the key to protecting vulnerable populations and improving long-term public health outcomes.