Visceral leishmaniasis-HIV coinfection: Time for Concerted Action

As PLOS Neglected Tropical Diseases launches its Visceral Leishmaniasis-HIV Collection, Johan van Griensven discusses the importance of a multidisciplinary approach to tackling VL-HIV co-infection.

In 2013, PLOS Neglected Tropical Diseases decided to dedicate a special collection to VL-HIV co-infection. With Ed Zijlstra, Asrat Hailu, and myself as guest editors, they sent out a call for papers. Today the Visceral Leishmaniasis-HIV Collection is launched, containing the first batch of submitted papers. Previously published content from across the various PLOS journals are also included. The collection will be expanded over time with novel publications published by PLOS.

VL-HIV coinfection is an emerging global problem. It is on the rise in South-America and the Indian subcontinent, which harbours more than half of the global VL burden. In North-West Ethiopia, up to 40% of patients with VL were found to be co-infected with HIV, mainly among seasonal migrant workers.

Currently, prognosis of VL-HIV coinfection is poor. In the setting where we work in Ethiopia, case fatality rates of up to 25% have been documented. Many patients do not respond to therapy, and if they do, around half relapse within the following year. To help address this problem, we founded the AfriCoLeish Consortium, supported through the European Union. Two clinical trials (one on secondary prophylaxis, one on VL combination therapy) are currently ongoing. While such initiatives are highly needed, we should move beyond.

Clinical research can only have a lasting impact on the ground if new interventions can be effectively implemented by national programs. As a neglected disease, VL and VL-HIV coinfection have traditionally not ranked high on the health agenda in many endemic countries. In East Africa, VL care is still highly dependent on international actors such as Medecins Sans Frontieres, the Drugs for Neglected Diseases initiative and the World Health Organization. Reinforcing national VL programs will be crucial.

While clinical research can help improve case management, a broader and deeper understanding of all dimensions of VL and VL-HIV coinfection is required to effectively tackle it. This calls for truly trans-disciplinary research initiatives, linking up with public health, environmental, and social sciences. Operational research is required to optimize the implementation of (cost-)effective and sustainable disease control activities and move towards VL elimination.

Clinical trials also provide unique opportunities for laboratory research, including biomarker/diagnostic studies, and cellular and molecular studies on the immunopathogenesis of VL-HIV coinfection. This would require linking the different disciplines and careful biobanking of precious samples. Few clinical trials or groups currently fully exploit or facilitate opportunities for nested laboratory studies and sample sharing. This merits exploration, though, since it might be a critical way to exponentially speed up the research process and develop novel tools.

Would it make sense to launch an international network or consortium, as recently done for post kala-azar dermal leishmaniasis? This could serve as a means for improved global surveillance, more effective advocacy and drafting of comprehensive research agendas and action plans. Such a network could also engender exchange of expertise and experience amongst stakeholders and standardization of research methodologies. Moreover, it could be the ideal vehicle to share bio specimens.

Progress towards elimination and control of VL and VL-HIV coinfection will ultimately hinge on the concerted efforts of all stakeholders, within a multidisciplinary approach, with research feeding into policy.