1
|
Joshi AB, Banjara MR, Das ML, Ghale P, Pant KR, Pyakurel UR, Dahal G, Paudel KP, Das CL, Kroeger A, Aseffa A. Epidemiological, Serological, and Entomological Investigation of New Visceral Leishmaniasis Foci in Nepal. Am J Trop Med Hyg 2024; 110:44-51. [PMID: 38011729 DOI: 10.4269/ajtmh.23-0373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 09/15/2023] [Indexed: 11/29/2023] Open
Abstract
The aim of this study was to explore epidemiological, serological, entomological, and social aspects of visceral leishmaniasis (VL) in new foci in Nepal. The study was conducted in 11 villages of five districts that had been previously free of VL but that reported new cases between 2019 and 2021. We screened 1,288 inhabitants using rK39 tests and investigated the epidemiological and clinical characteristics of 12 recent VL cases. A total of 182 community members were interviewed about knowledge, attitude, and practices regarding VL. They then underwent an awareness training; 40 of them had a second interview at 6 months to assess the training impact. Vector surveys were conducted in six houses per village to assess sandfly density and infection rates. The prevalence of VL infection was 0.5% and 3.2% among screened populations in Dolpa and Kavre districts, respectively, while the other districts had no rK39-positive cases. No association between travel history and VL infection was found. Phlebotomus argentipes sandflies were collected in three districts at high altitudes (from 1,084 to 4,450 m). None of the sandflies captured had Leishmania donovani DNA. People in new foci were not aware of VL symptoms, vectors, or preventive measures. The training significantly improved their knowledge and practice in seeking medical care in case of illness. The epidemiological, serological, and entomological investigations suggest indigenous focal transmission of VL. An integrated package of strategic interventions should be implemented by the national VL elimination program in districts with new VL foci.
Collapse
Affiliation(s)
- Anand Ballabh Joshi
- Public Health and Infectious Disease Research Center (PHIDReC), Kathmandu, Nepal
| | - Megha Raj Banjara
- Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu, Nepal
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), Geneva, Switzerland
| | - Murari Lal Das
- Public Health and Infectious Disease Research Center (PHIDReC), Kathmandu, Nepal
| | - Pragyan Ghale
- Public Health and Infectious Disease Research Center (PHIDReC), Kathmandu, Nepal
| | - Krishna Raj Pant
- Public Health and Infectious Disease Research Center (PHIDReC), Kathmandu, Nepal
| | - Uttam Raj Pyakurel
- Epidemiology and Disease Control Division, Department of Health Services, Teku, Kathmandu, Nepal
| | - Gokarna Dahal
- Epidemiology and Disease Control Division, Department of Health Services, Teku, Kathmandu, Nepal
| | - Krishna Prasad Paudel
- Epidemiology and Disease Control Division, Department of Health Services, Teku, Kathmandu, Nepal
| | - Chuman Lal Das
- Epidemiology and Disease Control Division, Department of Health Services, Teku, Kathmandu, Nepal
| | - Axel Kroeger
- Centre for Medicine and Society, Albert-Ludwigs-University, Freiburg, Germany
| | - Abraham Aseffa
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), Geneva, Switzerland
| |
Collapse
|
2
|
Maity S, Sengupta S, Sen M. Therapeutic potential of rWnt5A in curbing Leishmania donovani infection. Infect Immun 2023; 91:e0026723. [PMID: 37725061 PMCID: PMC10580910 DOI: 10.1128/iai.00267-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 07/24/2023] [Indexed: 09/21/2023] Open
Abstract
In view of the antagonism of Wnt5A signaling toward microbial pathogens, we were interested in evaluating the therapeutic potential of recombinant Wnt5A (rWnt5A) in curbing Leishmania donovani infection. Initially, using L. donovani-infected RAW 264.7 and peritoneal macrophages, we demonstrated that application of rWnt5A as opposed to the vehicle control to the infected cells significantly dampens L. donovani infection. Inhibition of infection was associated with increase in cell-associated reactive oxygen species (ROS), and blocked by the ROS production inhibitor diphenylene iodonium chloride (DPI). rWnt5A, but not the vehicle control (PBS: phosphate-buffered saline) administration to L. donovani-infected mice appreciably reduced the infection load, and inhibited disease progression as evident from the preservation of splenic white pulp architecture. rWnt5A administration, moreover, led to elevation of both cell-associated ROS and the activation of splenic T cells. Substantial increase in T cell-associated Interleukin-2 (IL-2) and Granzyme B (GRB) upon exposure of splenic lymphocytes harvested from rWnt5A-treated mice to L. donovani-infected RAW 264.7 macrophages in vitro validated the occurrence of L. donovani-responsive T cell activation in vivo. In summary, this study unveils the therapeutic potential of rWnt5A in curbing L. donovani infection and the progression of experimental visceral leishmaniasis possibly through increase in cellular ROS and T cell activation. Accordingly, it opens up a new avenue of investigation into the use of rWnt5A as a therapeutic agent for restraining the progression of drug-resistant L. donovani infection.
Collapse
Affiliation(s)
- Shreyasi Maity
- Division of Cancer Biology & Inflammatory Disorder, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India
| | - Soham Sengupta
- Division of Cancer Biology & Inflammatory Disorder, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India
| | - Malini Sen
- Division of Cancer Biology & Inflammatory Disorder, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India
| |
Collapse
|