BACKGROUND
Visceral leishmaniasis (VL) is a vector-borne disease caused by Leishmania parasites and transmitted by sand fly bites, targeted for elimination in India. VL primarily affects rural, low-income populations with limited health care access. In South Asia, few studies have explored patients’ perspectives, diagnoses, and treatment experiences; particularly lacking an understanding about the patients’ life experiences outside of clinical research settings.
METHODOLOGY/PRINCIPAL FINDINGS
A qualitative study was conducted in Bihar, India, using moderator-facilitated, protocol-defined discussion. Eighteen adult patients and 12 caregivers of children diagnosed with and treated for VL within the last 12 months were identified by self-report. Mean time from symptom onset to diagnosis was 13.8 days. Challenges of the early patient life experience included lack of urgency by health care professionals, delayed diagnosis, and no guarantee of treatment at the location of their VL diagnosis (63% had to switch to a different center for treatment, at times delaying treatment). Key barriers identified in previous studies that were re-confirmed in this study include out-of-pocket financial burden, absence from work/home duties, and long-distance travel to hospitals. Patients and caregivers (n = 29/30) expressed a preference for a potential oral treatment that could be taken close to home.
CONCLUSIONS/SIGNIFICANCE
This study reveals new insights about the patient life experience and reconfirms previous research indicating that access to care for patients with VL in the Bihar area remains a challenge. Although most patients with VL seek care early, diagnosis often requires multiple visits to a health care facility. Despite access to therapy in public hospitals, some patients reported a preference for private care. Even if diagnosis takes place in a government-funded public setting, some patients reported needing to move from the location of diagnosis to another center to receive therapy, creating an additional burden for patients. As a potential alternative to current parenteral treatment, adult patients and caregivers of pediatric patients expressed interest in a potential oral therapy because it may reduce barriers to access care.
Treatment regimens for post-kala-azar dermal leishmaniasis (PKDL) are usually extrapolated from those for visceral leishmaniasis (VL), but drug pharmacokinetics (PK) can differ due to disease-specific variations in absorption, distribution, and elimination. This study characterized PK differences in paromomycin and miltefosine between 109 PKDL and 264 VL patients from eastern Africa. VL patients showed 0.55-fold (95%CI: 0.41-0.74) lower capacity for paromomycin saturable reabsorption in renal tubules, and required a 1.44-fold (1.23-1.71) adjustment when relating renal clearance to creatinine-based eGFR. Miltefosine bioavailability in VL patients was lowered by 69% (62-76) at treatment start. Comparing PKDL to VL patients on the same regimen, paromomycin plasma exposures were 0.74-0.87-fold, while miltefosine exposure until the end of treatment day was 1.4-fold. These pronounced PK differences between PKDL and VL patients in eastern Africa highlight the challenges of directly extrapolating dosing regimens from one leishmaniasis presentation to another.
Background
People with human immunodeficiency virus (PWH) with recurrent visceral leishmaniasis (VL) could potentially drive Leishmania transmission in areas with anthroponotic transmission such as East Africa, but studies are lacking. Leishmania parasitemia has been used as proxy for infectiousness.
Methods
This study is nested within the Predicting Visceral Leishmaniasis in HIV-InfectedPatients (PreLeisH) prospective cohort study, following 490 PWH free of VL at enrollment for up to 24–37 months in northwest Ethiopia. Blood Leishmania polymerase chain reaction (PCR) was done systematically. This case series reports on 10 PWH with chronic VL (≥3 VL episodes during follow-up) for up to 37 months, and 3 individuals with asymptomatic Leishmania infection for up to 24 months.
Results
All 10 chronic VL cases were male, on antiretroviral treatment, with 0–11 relapses before enrollment. Median baseline CD4 count was 82 cells/µL. They displayed 3–6 VL treatment episodes over a period up to 37 months. Leishmania blood PCR levels were strongly positive for almost the entire follow-up (median cycle threshold value, 26 [interquartile range, 23–30]), including during periods between VL treatment. Additionally, we describe 3 PWH with asymptomatic Leishmania infection and without VL history, with equally strong Leishmania parasitemia over a period of up to 24 months without developing VL. All were on antiretroviral treatment at enrollment, with baseline CD4 counts ranging from 78 to 350 cells/µL.
Conclusions
These are the first data on chronic parasitemia in PWH from Leishmania donovani–endemic areas. PWH with asymptomatic and symptomatic Leishmania infection could potentially be highly infectious and constitute Leishmania superspreaders. Xenodiagnosis studies are required to confirm infectiousness.
Visceral leishmaniasis (VL) is a neglected tropical disease prevalent in populations affected by poverty, war, and famine. Without effective treatment, death is the norm. Prognostic models, as used by Médecins Sans Frontières (MSF) in East Africa, are used to identify high-risk patients for intensive management, including hospital admission, treatment with liposomal amphotericin B, broad-spectrum antibiotics, and blood transfusions. We provide a comprehensive and objective resource for policymakers, healthcare providers, and investigators, by identifying, summarising, and appraising the available prognostic models predicting clinical outcomes in patients with VL.
METHODS
We performed a systematic review of published studies that developed, validated, or updated models predicting future clinical outcomes in patients diagnosed with VL. We searched five bibliographic databases (Ovid Embase, Ovid MEDLINE, Web of Science Core Collection, SciELO, and LILACS) on March 1, 2023, for papers published from database inception, with no language restriction. Screening, data extraction, and risk of bias assessment were performed in duplicate. This study is registered with PROSPERO (ID: CRD42023417226).
RESULTS
Eight prognostic model studies, published between 2003 and 2021, were identified describing 12 prognostic model developments and 19 external validations. Nine models were developed in Brazil and three in East Africa by MSF investigators (two developed in South Sudan and one in Ethiopia). In-hospital mortality was the outcome for all but two Brazilian models, which predicted registry-reported mortality. Three models were developed exclusively in adolescents or children. Risk of bias was assessed as high for all model evaluations. Model overfitting due to small sample sizes, leading to optimistic model performance measures and exaggerated risk estimates, was identified for all but one model development. Only half of the presented risk scores were reproducible by following the authors’ methodology.
CONCLUSION
A poorly developed model can result in inaccurate risk estimation, potentially leading to harmful and inequitable decision making. With half of all risk scores incorrectly calculated, and a high risk of bias identified across all model evaluations, caution must be exercised when using these models to guide patient management. In the first systematic review of VL prognostic models, we show that no models predicted treatment failure and relapse, and despite South Asia representing the highest VL burden before 2010, no models were developed in this population. These represent important evidence gaps, which should be prioritised when developing new models. Using the Infectious Diseases Data Observatory repository of VL individual patient data from clinical trials, we are currently building a prognostic model for VL relapse in South Asia, which we hope to serve the ongoing elimination campaign.