WHO updates treatment guidelines for visceral leishmaniasis and PKDL

WHO revises leishmaniasis treatment protocols

The World Health Organization has released updated treatment guidelines for visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL), marking a shift in how these neglected tropical diseases are managed globally.

The revision, published this week, incorporates new evidence from clinical trials conducted in endemic regions, including parts of India, Bangladesh, and East Africa. Visceral leishmaniasis, also known as kala-azar, is a parasitic disease transmitted by sandflies. If left untreated, it is almost always fatal.

Post-kala-azar dermal leishmaniasis is a skin condition that can develop in patients who have recovered from VL. The rash serves as a reservoir for the parasite, making treatment crucial for controlling transmission.

New drug combinations take centre stage

The updated guidelines recommend combination therapies over monotherapy for first-line treatment of VL. The WHO now endorses a regimen combining liposomal amphotericin B with miltefosine, and another combining paromomycin with miltefosine.

These combinations aim to reduce treatment duration and lower the risk of drug resistance. For PKDL, the new protocols shorten the course of miltefosine from 12 weeks to 8 weeks in most cases, based on data showing comparable efficacy.

Health officials in Bihar and West Bengal, states that report the highest number of VL cases in India, have already begun reviewing the changes. The National Vector Borne Disease Control Programme is expected to issue an advisory to state health departments soon.

Implications for India's elimination target

India has been working towards eliminating VL as a public health problem by 2025, a target set by the WHO South-East Asia Regional Office. The new guidelines could accelerate progress by making treatment more accessible and affordable.

Shorter regimens mean fewer hospital visits and lower out-of-pocket costs for patients, many of whom live in rural, impoverished communities. The WHO noted that the updated protocols also simplify diagnosis and case management at primary health centres.

However, challenges remain. Access to liposomal amphotericin B, which must be stored at specific temperatures, is limited in remote areas. The WHO has urged governments and partners to strengthen supply chains and training for health workers.

Focus on PKDL as a hidden reservoir

Post-kala-azar dermal leishmaniasis has long been neglected in control programmes. Patients with PKDL can harbour parasites for years and infect sandflies, perpetuating the disease cycle even when VL cases decline.

The new guidelines emphasise active case finding for PKDL and integration of its treatment into routine VL services. The WHO recommends that all patients treated for VL be followed up for at least 12 months to detect PKDL early.

In India, community health workers in endemic districts have been trained to identify and refer PKDL cases. The updated WHO protocols provide clearer criteria for diagnosis and treatment, which should boost these efforts.

Global health experts have welcomed the revision. Dr. Shyam Sundar, a leading leishmaniasis researcher at the Banaras Hindu University, described the update as a significant step forward. “These evidence-based changes will save lives and bring us closer to elimination,” he said.

The WHO has also called for increased funding for research into new drugs and vaccines. No vaccine currently exists for leishmaniasis, and treatment options remain limited compared to other infectious diseases.

Implementation of the new guidelines will be phased over the next year. The WHO plans to release operational manuals and conduct training workshops in high-burden countries. India's health ministry is expected to incorporate the changes into its national protocols by early 2027.