ZSI study on blackflies offers hope for river blindness control

DNA barcoding aids in identifying blackfly species to improve river blindness management, crucial for public health protection.

A new study involving DNA barcoding to identify species accurately is expected to lead to better management and control strategies for blackflies, which are carriers of a worm causing river blindness.

The findings by a team from the Diptera division of the Zoological Survey of India (ZSI) were published in Vector-Borne and Zoonotic Diseases, a leading international research journal. The authors of the study are Arka Mukherjee, Oishik Kar, Koustav Mukherjee, Bindarika Mukherjee, Atanu Naskar, and Dhriti Banerjee.

River blindness is a parasitic disease caused by the worm Onchocerca volvulus, transmitted through the bites of infected blackflies that breed near fast-flowing rivers, leading to skin problems and potential blindness.

River blindness follows trachoma as the leading cause of infection-related blindness worldwide. The World Health Organisation (WHO) considers river blindness or onchocerciasis among the most neglected tropical diseases.

The ZSI team collected blackflies or Simuliidae from eight distinct central Himalayan locations around Kalimpong and Darjeeling in West Bengal. These blackflies are locally called pipsa or potu.

A recent world inventory lists 2,424 species of Simuliidae, of which at least 27 species or species complexes are known to transmit Onchocerca volvulus, the causative agent of the disease in humans.

The researchers said the first step in protecting people from this disease was to properly identify and control the vector — the blackfly. Better identification of the disease carrier was thus deemed essential for improved treatment.