Visceral leishmaniasis and HIV coinfection in Bihar, India: a wake-up call?

Abstract

Visceral leishmaniasis (VL) is a vectorborne protozoan infection caused by the Leishmania donovani spp. complex. Typical disease manifestations include persistent fever, hepatosplenomegaly, and pancytopenia [1]. Without treatment, overt VL is universally fatal. The disease is a global health problem, with an estimated annual incidence of 200 000– 400 000 cases [2]. VL caused by Leishmania infantum (chagasi) is prevalent in Latin America and the Mediterranean region, whereas L. donovani causes VL in East Africa and the Indian subcontinent. Around 90% of VL in India and almost half of the global burden occur in Bihar, a state in northeast India, with a population of more than 100 million [3]. Afflicted by poverty, this region also is home to large numbers of migrant workers who travel to and from the major cities in the region. Human immunodeficiency virus (HIV) coinfection of VL has been identified as an emerging challenge for VL control [4]. HIV infection dramatically increases the risk of VL and, conversely, VL accelerates HIV disease progression. Historically, VL–HIV coinfection prominently emerged in Europe in the early 1990s, where up to 60% of VL cases were coinfected [4]. With the introduction of antiretroviral therapy (ART) in the late 1990s, the incidence of new VL–HIV cases gradually declined [4]. The problem is now severe in some parts of eastern Africa, particularly Ethiopia, where up to 40% of VL patients are HIV coinfected [4]. In Brazil, coinfection was documented in 6% of VL cases in 2011 [5]. In this issue of Clinical Infectious Diseases, Burza and colleagues report on a large group of adult VL patients (aged 14 years) who were systematically offered HIV testing within a VL program run by Medecins Sans Frontieres (MSF) in Bihar, India [6]. Of the 2130 individuals diagnosed with VL over an 18-month period, 2077 (97.5%) agreed to HIV testing, of whom 117 (5.6%) were found to be HIV positive. This included 49 (2.4%) newly diagnosed HIV cases and 68 (3.3%) cases that had been diagnosed previously at other health facilities and were retested in the MSF program. Males aged 35–44 years were most markedly affected, with a total HIV prevalence of 12.8% and a prevalence of previously undiagnosed HIV of 5.4%. While the strengths of the report include the large sample size and the high uptake of HIV testing, the data come from a single nongovernmental program that provides free VL care and can obviously not be considered a representative sample. The authors acknowledge that the estimate could be inflated by the fact that the MSF program has an interest in VL–HIV coinfection and might attract referrals of coinfected patients from other centers. Nevertheless, newly diagnosed HIV infection in 2.4% of VL cases, which would have been missed without routine HIV testing, is still high. Assuming quality-assured testing, the applied HIV diagnostic algorithm should be appropriate, with very rare false-positive results. However, the use of 1 of the HIV rapid diagnostic tests in the MSF program could theoretically have led to a few missed diagnoses of HIV. The increased likelihood of atypical presentation of VL and the reportedly lower sensitivity of serological tests for VL in HIV-infected patients could possibly further contribute to underdiagnosis [7]. There are also few data to triangulate these findings. The limited number of studies on the topic have generally included very few patients. On the other hand, the VL–HIV coinfection rate reportedly increased from 0.88% (339 cases, presumably adults and children combined) in 2000 to 2.18% (776 cases) in 2006 at a major VL clinical trial center in the region [4]. Although further studies and enhanced surveillance are required to more accurately define the Received 24 April 2014; accepted 25 April 2014. Correspondence: Johan van Griensven, MD, MSc, PhD, Institute of Tropical Medicine, 2000 Antwerp, Belgium (jvangriensven@itg.be). Clinical Infectious Diseases The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Societyof America. All rights reserved. For Permissions, please e-mail: journals. permissions@oup.com. DOI: 10.1093/cid/ciu334