According to the World Health Organization, lymphatic filariasis (LF) affects 120 million people globally, making it one of the world’s leading causes of clinical morbidity and disfigurement. This debilitating condition leads to the abnormal enlargement of various body parts, most commonly the legs and knees, causing disability and disfigurement. In fact, the disease is the second leading cause of permanent, long-term disability.
Asia is home to nearly two-thirds of all infected individuals. In India, this disease is a major public health problem as it is widespread across the country. It is endemic in 256 districts across 17 states in India.
Mass Drug Administration
India first started mass drug administration in 2004 with a single drug, switching to two drugs in 2008. Once the rate of microfilaria is reduced to below one percent, the conditions for interruption of the transmission are created, making elimination of the disease an achievable goal. So far, 99 of the 256 endemic districts in India have successfully interrupted the transmission of lymphatic filariasis, achieving a less than one percent microfilaria rate. Microfilaria rates are currently being validated by a transmission assessment survey under post-mass drug administration surveillance.
The remaining 157 districts are either implementing the mass drug administration or preparing for the survey. It is in these districts that transmission of the disease continues to be problematic, persisting even after five rounds of drug administration.
Switching to Triple Drug Therapy
In 2017, the World Health Organization recommended an alternate regimen to help accelerate elimination of lymphatic filariasis globally: triple drug therapy. This new treatment, also called IDA, combined the two drugs that were being used with Ivermectin. Research found that the triple drug regimen was faster and more effective at clearing microfilaria than the mass drug administration regimen.
In 2018, India introduced a pilot triple-drug therapy regimen across four districts. This new medical combination will eventually be used to accelerate lymphatic filariasis elimination efforts in the remaining 157 endemic districts.
Development of the dose pole
In order to help the government achieve its elimination goals, the Neglected Tropical Diseases and Malaria team at PATH India has provided assistance to the National Vector Borne Disease Control Program (NVBDCP), an arm of the Ministry of Health and Family Welfare, Government of India. PATH is providing technical assistance at the country and state levels for lymphatic filariasis elimination activities, along with support for the introduction of triple drug therapy. With PATH’s support, NVBDCP developed the operational guidelines, multiple-training resource materials, and an innovative 'dose pole' for determining the required dosage of Ivermectin.
How does the dose pole work?
The Directorate of National Vector Borne Disease Control recommends administering Ivermectin according to the height of the individual. During drug administration campaigns, the dose pole is used by health workers to ascertain the correct dosage of Ivermectin.
The dose pole is a simple six foot pole that can be retracted into four foldable pieces, making it easy for health workers to carry. A color-coded vinyl sticker is pasted on the external surface of the dose pole and each colour corresponds to the dose of Ivermectin required to be administered for a range of heights. It is the result of combining PATH’s innovation with its extensive on-ground expertise. It will be a valuable resource for health workers in low-resource settings. The pole has so far been used in four districts across India.
The use of height to determine dosage of Ivermectin has been incorporated in mass drug administration programs across Sierra Leone, Kenya, Sudan, and Burkina Faso. The dose pole is a practical solution when working in low-resource field conditions and is preferable to weighing machines as it does not require frequent calibration or any power source.
This innovation by PATH will help with India’s ambitious goal of eliminating lymphatic filariasis. India is one the first countries globally to roll out triple-drug therapy and the experience can inform similar introduction efforts in other countries where this disease is prevalent. PATH will continue to support the national and state governments and partners to help bring India closer to the goal of eliminating lymphatic filariasis from the country.