Clinical Research Directory

Diagnosis and Treatment of Leishmania Infections

This study will examine the natural history of Leishmanial infections and their treatments. It will provide an opportunity for NIAID staff to learn more about leishmaniasis and perhaps to improve diagnostic tests for these infections. Patients between 2 and 80 years of age with known or suspected leishmaniasis are eligible for this study. Participants will have routine blood tests and a biopsy to confirm leishmanial infection. The biopsy procedure will be determined by the type of infection local cutaneous leishmaniasis (LCL), mucocutaneous leishmaniasis (MCL) or visceral leishmaniasis (VL). CL will be confirmed with a punch biopsy, in which a cookie-cutter type razor is used to remove a small circular piece of skin tissue. MCL will be confirmed using a thin flexible tube inserted into the nose. This tube is used to examine the nose and upper airway and to remove a tissue sample, if an affected area is seen. VL will be confirmed with either a bone marrow or liver biopsy or a splenic aspirate. For these procedures, a small tissue sample is withdrawn through a needle placed in the hipbone, liver or spleen, respectively. Some patients may also have a skin test for leishmaniasis similar to tuberculin skin testing. Treatment and length of hospital stay are determined by the type of infection. CL may be treated with Pentostam, amphotericin, amphotericin B, itraconazole or ketoconazole; ML with amphotericin B, or encapsulated amphotericin; and VL with Pentostam or encapsulated amphotericin. Pentostam is infused daily for 18 to 28 doses, most as an outpatient. Blood is drawn 3 times a week for safety tests and an electrocardiogram is done 2 to 3 times a week to monitor heart rhythm. Amphotericin B is infused every day or every other day for about 30 doses, all on an inpatient basis. Patients undergo hydration (infusion of a large amount of fluid) just before and immediately after each infusion to protect the kidneys. Blood is drawn every other day and urine samples are collected occasionally for routine urinalysis. Encapsulated amphotericin is infused every other day, on an outpatient basis. Blood is generally drawn every other day to every 2 days and urinalyses are done periodically. Itraconazole and ketoconazole are taken orally for at least 1 to 3 months, with blood drawn every 2 to 3 weeks. Patients may be asked to have photographs taken before, during and after treatment to document progress. They may also be asked to provide extra blood samples for research purposes, either through a vein in the arm or through apheresis, a method for collecting large numbers of cells. For apheresis, whole blood is collected through a needle in an arm vein and circulated through a machine that separates it into its components. The desired cells are then removed, and the rest of the blood is returned to the body, either through the same needle used to draw the blood or through a second needle in the other arm. Patients with cutaneous leishmaniasis will have a follow-up clinic visit 2 weeks to 3 months after treatment is completed. If there are no complications, their participation will end at that time. Patients with mucocutaneous leishmaniasis and visceral leishmaniasis will be followed every 3 to 6 months indefinitely for routine evaluations and re-treatment if the infection recurs.

Risk Assessment of Community Spread of Multiple Endemic Infectious Diseases in a One Health Perspective

RACSMEI addresses the high burden of infectious diseases in low- and middle-income countries, including Cambodia, where limited surveillance and laboratory capacity often obscure etiologies and transmission dynamics. This knowledge gap hinders the design of effective prevention and control strategies. RACSMEI will improve understanding across multiple pathogens using a multidisciplinary One Health approach. We will answer key questions on burden, ecology, transmission and population immune status to inform targeted and culturally appropriate interventions. The project combines a nationally representative One Health survey, social-science methods, and multiplex, diverse diagnostics to efficiently test for 57 priority pathogens, including zoonotic and vector-borne agents, vaccine-preventable and elimination-targeted diseases, enteric, respiratory, and environmentally transmitted pathogens and selected neglected tropical diseases and parasites relevant to Cambodia. Mathematical modelling will reconstruct and forecast transmission dynamics and assess the potential impact of future public-health strategies. By integrating intersectoral data and innovative methods, RACSMEI will generate actionable evidence for public-health authorities, support precision One Health interventions, and help reduce disease burden in affected communities. The project also aims to ensure the transferability of methods and insights to other countries facing similar challenges.

Mediterranean Visceral Leishmaniasis With Leishmania Infantum

L. infantum leishmaniasis is endemic in the South of France. For several years, there has been an expansion of the territory of sandflies (vector of leishmaniasis), with the appearance of cases of canine leishmaniasis in new outbreaks: West of the Occitania region (South-West). The transition from asymptomatic to disease depends largely on the immune status of the carrier, but many other factors specific to the parasite and host remain poorly defined. Asymptomatic carriage is present in a large majority of infected subjects, however, to date, only parasite isolates causing the patent form have been characterized. In this PHRC, the team wishes to study the genetics of parasite isolates present in asymptomatic carriers of the Alpes-Maritimes outbreak and the new Occitanie outbreak as well as the genetics of the host. The primary objective is the genetic characterization of L. infantum isolates by the microsatellite method, present in asymptomatic carriers in southeast and southwestern France. The secondary objectives are: 1. Comparison of the genetic profiles of L. infantum isolates, by microsatellite method, from asymptomatic carriers of the new Southwestern outbreak with isolates from asymptomatic carriers of the historical Southwestern outbreak. 2. Comparison of the genetic profiles of L. infantum isolates, by the microsatellite method, present in asymptomatic carriers in the Southeast with the profiles of isolates present in patients in the same outbreak, for whom a microsatellite study has already been obtained previously. 3. the team is also conducting a preliminary study of the host genetic factors that would be associated with asymptomatic carriage by studying the association between potential host-related genetic risk factors (HLA typing, NLRP3 gene study) and asymptomatic carriage. Indeed, a recent study showed that the NLRP3 gene prevents the development of the patent form of leishmaniasis in the mouse model. This preliminary genetic study will identify potential host-related factors associated with asymptomatic carriage. To meet these objectives, leuco-platelet layer parasites (CLP) obtained via EFS from the 2 sources of interest will be isolated. This project is a research not involving the human person. It is multicentric and non-randomized. As a result of this research, isolates from asymptomatic carriers of the historical outbreak will be studied and compared to those present in new endemic outbreaks, as well as to those of patients already studied in a previous study. A better knowledge of parasites circulating in asymptomatic carriers will make it possible to study in a comprehensive way the risk factors associated with the parasite. In addition, the study of asymptomatic carrying in new endemic outbreaks such as Occitania is very original, since no human studies have yet been undertaken in this region. The results obtained in this PHRC will be used to understand the factors associated with the development of visceral leishmaniasis.

Serological Measurement of Montpellier Professionals' Contacts with Infectious Agents Responsible for Animal-borne Diseases

Zoonoses and arboviroses refer to a group of diseases transmitted from animals to humans, either directly or indirectly (via mosquitoes, ticks or contact with contaminated environments). Most of these diseases are found in certain tropical zones, but global warming and increased international trade are modifying their geographical distribution, with a gradual trend towards temperate regions. A number of these pathogens have already been detected in Occitania, including dengue fever, West Nile, leishmaniasis and Q fever. Given the region's high mosquito population and favorable climatic conditions, other zoonoses have a strong potential to appear in the region, or may already be circulating at a low level. The study focuses on 18 pathogens selected for their potential to emerge and establish themselves in the Occitanie region: Leishmaniasis, Leptospirosis, Brucellosis, Q fever, Rickettsiosis, Tularemia, Psittacosis, Lyme disease, Tick-borne encephalitis, Hantavirus, Hepatitis E virus, Dengue virus, Zika virus, Chikungunya virus, West-Nile virus, Usutu virus, Toscana virus, Crimean-Congo haemorrhagic fever virus. The aim of the study is to find out whether patients have antibodies against these infectious agents, which would indicate that they have been exposed to them in the past, even in the absence of symptoms. Describing the circulation of these pathogens will enable to implement appropriate public health measures to avoid the risk of epidemics (mosquito control, informing professionals, etc.), as well as to assess the risk incurred in the workplace and have this risk recognized by the healthcare system.

Human Leishmaniasis: Antigen Recognition Pattern and Study of New Potential Biomarkers

This is an exploratory experimental multicentre study on archived serum samples and on prospectively collected serum samples and blood samples. General objectives of the study are: to identify specific biomarkers in order to develop more accurate serological tests for the screening of Leishmania infections that does not present cross-reaction with other infectious diseases; to unveil the Antigen Recognition Patterns (ARPs) of Leishmania infection in humans; to verify whether the ARPs and the new biomarkers are common to different Leishmania infantum strains isolated in Italy as well as in other part of the World and to different strains of L. donovani isolated in Sudan as well as in other part of the World and discard any possible cross reaction with other infectious diseases such as Chagas, TB, leprosy or malaria.

The Association of Miltefosine and Pentoxifylline to Treat Mucosal and Cutaneous Leishmaniasis: A Clinical Trial in Brazil

Mucocutaneous leishmaniasis is endemic in the central region of Brazil and other countries worldwide. The standard treatment with meglumine antimoniate has a high rate of important adverse effects. This interventional study consists in a randomized clinical trial to access efficacy and safety of the association of miltefosine and pentoxifylline compared to meglumine antimoniate and pentoxifyline.