scholarly journals Human leishmaniasis vaccines: Use cases, target population and potential global demand

2021 ◽  
Vol 15 (9) ◽  
pp. e0009742
Author(s):  
Stefano Malvolti ◽  
Melissa Malhame ◽  
Carsten F. Mantel ◽  
Epke A. Le Rutte ◽  
Paul M. Kaye
Keyword(s):  
Visceral Leishmaniasis ◽  
Cutaneous Leishmaniasis ◽  
Target Population ◽  
Use Cases ◽  
Effective Vaccine ◽  
Development Effort ◽  
Prophylactic Vaccine ◽  
Routine Immunisation ◽  
Kala Azar ◽  
Human Leishmaniasis

The development of vaccines against one or all forms of human leishmaniasis remains hampered by a paucity of investment, at least in part resulting from the lack of well-evidenced and agreed estimates of vaccine demand. Starting from the definition of 4 main use cases (prevention of visceral leishmaniasis, prevention of cutaneous leishmaniasis, prevention of post-kala-azar dermal leishmaniasis and treatment of post-kala-azar dermal leishmaniasis), we have estimated the size of each target population, focusing on those endemic countries where incidence levels are sufficiently high to justify decisions to adopt a vaccine. We assumed a dual vaccine delivery strategy, including a wide age-range catch-up campaign before the start of routine immunisation. Vaccine characteristics and delivery parameters reflective of a target product profile and the likely duration of the clinical development effort were considered in forecasting the demand for each of the four indications. Over a period of 10 years, this demand is forecasted to range from 300–830 million doses for a vaccine preventing visceral leishmaniasis and 557–1400 million doses for a vaccine preventing cutaneous leishmaniasis under the different scenarios we simulated. In a scenario with an effective prophylactic visceral leishmaniasis vaccine, demand for use to prevent or treat post-kala-azar dermal leishmaniasis would be more limited (over the 10 years ~160,000 doses for prevention and ~7,000 doses for treatment). Demand would rise to exceed 330,000 doses, however, in the absence of an effective vaccine for visceral leishmaniasis. Because of the sizeable demand and potential for public health impact, a single-indication prophylactic vaccine for visceral or cutaneous leishmaniasis, and even more so a cross-protective prophylactic vaccine could attract the interest of commercial developers. Continuous refinement of these first-of-their kind estimates and confirmation of country willingness and ability to pay will be paramount to inform the decisions of policy makers and developers in relation to a leishmaniasis vaccine. Positive decisions can provide a much-needed contribution towards the achievement of global leishmaniasis control.

scholarly journals Human leishmaniasis vaccines: use cases, target population and potential global demand

2021 ◽  
Author(s):  
Stefano Malvolti ◽  
Melissa Malhame ◽  
Carsten Mantel ◽  
Epke A Le Rutte ◽  
Paul M Kaye
Keyword(s):  
Visceral Leishmaniasis ◽  
Cutaneous Leishmaniasis ◽  
Target Population ◽  
Use Cases ◽  
Effective Vaccine ◽  
Development Effort ◽  
Prophylactic Vaccine ◽  
Routine Immunisation ◽  
Kala Azar ◽  
Human Leishmaniasis

The development of vaccines against one or all forms of human leishmaniasis remains hampered by a paucity of investment, at least in part resulting from the lack of well-evidenced and agreed estimates of vaccine demand. Starting from the definition of 4 main use cases (prevention of visceral leishmaniasis, prevention of cutaneous leishmaniasis, prevention of post-kala-azar dermal leishmaniasis and treatment of post-kala-azar dermal leishmaniasis), we have estimated the size of each target population, focusing on those endemic countries where incidence levels are sufficiently high to justify decisions to adopt a vaccine. We assumed a dual vaccine delivery strategy, including a wide age-range catch-up campaign before the start of routine immunisation. Vaccine characteristics and delivery parameters reflective of a target product profile and the likely duration of the clinical development effort were considered in forecasting the demand for each of the four indications. Over a period of 10 years, this demand is forecasted to range from 310-830 million doses for a vaccine preventing visceral leishmaniasis and 557-1400 million doses for a vaccine preventing cutaneous leishmaniasis under the different scenarios we simulated. In a scenario with an effective prophylactic visceral leishmaniasis vaccine, demand for use to prevent or treat post-kala-azar dermal leishmaniasis would be more limited (over the 10 years ~160,000 doses for prevention and ~7,000 doses for treatment). Demand would rise to exceed 330,000 doses, however, in the absence of an effective vaccine for visceral leishmaniasis. Because of the sizeable demand and potential for public health impact, a single-indication prophylactic vaccine for visceral or cutaneous leishmaniasis, and even more so a cross-protective prophylactic vaccine could attract the interest of commercial developers. Continuous refinement of these first-of-their kind estimates and confirmation of country willingness and ability to pay will be paramount to inform the decisions of policy makers and developers in relation to a leishmaniasis vaccine. Positive decisions can provide a much-needed contribution towards the achievement of global leishmaniasis control.

scholarly journals Misdiagnosis and Mistreatment of Post-Kala-Azar Dermal Leishmaniasis

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ahmed Mohamed El Hassan ◽  
Eltahir Awad Gasim Khalil ◽  
Waleed Mohamed Elamin ◽  
Lamyaa Ahmed Mohamed El Hassan ◽  
Mogtaba Elsaman Ahmed ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Cutaneous Leishmaniasis ◽  
Past History ◽  
Previous History ◽  
Clinical Appearance ◽  
Kala Azar ◽  
Pcr Diagnosis ◽  
The Face ◽  
History Of ◽  
High Parasite

Post-kala-azar dermal leishmaniasis (PKDL) is a known complication of visceral leishmaniasis (VL) caused byL. donovani. It is rare in VL caused byL. infantumandL. chagasi. In Sudan, it occurs with a frequency of 58% among successfully treated VL patients. In the majority of cases, PKDL can be diagnosed on the basis of clinical appearance, distribution of the lesions, and past history of treated VL. The ideal diagnostic method is to demonstrate the parasite in smears, by culture or PCR. Diagnosis is particularly difficult in patients who develop PKDL in the absence of previous history of visceral leishmaniasis. We describe a case of cutaneous leishmaniasis misdiagnosed as PKDL and 3 cases of PKDL who were either misdiagnosed or mistreated as other dermatoses. This caused exacerbation of their disease leading to high parasite loads in the lesions and dissemination to internal organs in one of the patients, who was also diabetic. The latter patient hadL. majorinfection. A fourth patient with papulonodular lesions on the face and arms of 17-year duration and who was misdiagnosed as having PKDL is also described. He turned out to have cutaneous leishmaniasis due toL. major. Fortunately, he was not treated with steroids. He was cured with intravenous sodium stibogluconate.

scholarly journals Emergence of visceral leishmaniasis in Kollam district, Kerala, southern India

2019 ◽  
Vol 6 (3) ◽  
pp. 1350 ◽  
Author(s):  
R. Sandhya ◽  
P. S. Rakesh ◽  
Soumya Dev
Keyword(s):  
Visceral Leishmaniasis ◽  
Cutaneous Leishmaniasis ◽  
Southern India ◽  
Outbreak Investigation ◽  
Epidemiological Analysis ◽  
Major Threat ◽  
Kala Azar ◽  
Epidemiological Link

An outbreak investigation was initiated following an unusual occurence of kala azar reported among people residing in the tribal belt of Kulathupuzha area, eastern part of Kollam district, Kerala, Southern India. 2 cases of kala azar were investigated during 2016-2018. Epidemiological analysis indicated no epidemiological link between the cases. However the Visceral leishmaniasis and cutaneous leishmaniasis intruding into newer regions pose a major threat to ongoing leishmaniasis elimination and maintenance programs.

Workshop no. 11. Ecology of Leishmania

Parasitology ◽  
1981 ◽  
Vol 82 (4) ◽  
pp. 143-152 ◽  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Kala Azar ◽  
Phlebotomine Sandflies ◽  
Human Leishmaniasis ◽  
Vertebrate Hosts ◽  
Reservoir Hosts

The ecology of Leishmania of man is concerned with the circulation of the parasite in nature from one mammal to another by the bite of phlebotomine sandflies. The natural vertebrate hosts are anthropocentrieally referred to as reservoir hosts although in sorac foci of human leishmaniasis (anthroponotic cutaneous leishmaniasis and Indian kala-azar) man himself is thought to be the reservoir.

scholarly journals Investigations on mediterranean Kala Azar. VI.—Canine visceral leishmaniasis

1932 ◽  
Vol 110 (768) ◽  
pp. 402-412 ◽  
Keyword(s):  
Visceral Leishmaniasis ◽  
Cutaneous Leishmaniasis ◽  
Canine Leishmaniasis ◽  
Causative Organism ◽  
Extensive Literature ◽  
Canine Visceral Leishmaniasis ◽  
Human Beings ◽  
Kala Azar ◽  
Human Adults ◽  
Direct Experiment

Following the discovery of canine visceral Leishmaniasis in Tunis by Nicolle and Comte (1908), an extensive literature has developed dealing particularly with the possible relationship between human and canine Leishmaniasis. Most authors, following Nicolle, consider Leishmania infantum , to be the causative organism of both human and canine Kala Azar. In the case of cutaneous Leishmaniasis, L. tropica has been conclusively proved by direct experiment to be the causative organism in both man and dog (1930), but in this case there is no evidence that the dog serves as a reservoir of the human disease. It is more likely that where human and canine cutaneous Leishmaniasis co-exist, human beings serve as a reservoir from which dogs are infected (1929). It is, however, difficult to carry out similar direct experiments with visceral Leishmaniasis, for human adults are naturally immune to Mediterranean Kala Azar.

DETECTION OF LEISHMANIA INFECTION IN STRAY DOGS IN HUMAN LEISHMANIASIS ENDEMIC AREA IN MYMENSINGH DISTRICT WITH ITS POSSIBLE PUBLIC HEALTH SIGNIFICANCE IN BANGLADESH

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
M. A. Hossen
Keyword(s):  
Visceral Leishmaniasis ◽  
Asymptomatic Carrier ◽  
Asymptomatic Infection ◽  
Reservoir Host ◽  
Sand Fly ◽  
Leishmania Infection ◽  
Endemic Region ◽  
Stray Dogs ◽  
Human Leishmaniasis ◽  
Strip Test

Background: Leishmaniasis is primarily caused by two species of Leishmania (L. donovani and L. infantum) of which clinical infection with L. infantum has been recognized in both humans and dogs as zoonotic disease with dogs as the main reservoir hosts in the Mediterranean, the Middle East, Asia and South America. Although L. donovani has been associated with both clinical and asymptomatic infection in humans but it is still associated with asymptomatic infection in dogs in Indian sub-continent without any evidence of zoonotic infection. Objectives: The objective of this research was to investigate the potentiality of dog as reservoir host for visceral leishmaniasis in the human leishmaniasis endemic regions in Bangladesh. Materials and Methods: A total of 20 stray dogs in the human VL endemic areas of Mymensingh district were captured for the detection VL during the period of November 2010 to May 2011. The dipstick test rK39 (Bios International; n = 20), Giemsa’s stained impression smears of liver and spleen (n = 6) and PCR with the tissue of liver and spleen (n = 6) were tested as per manufacturer instructions and conventional standard methods. Results: Out of 20 stray dogs examined, 4 (20.0%) were positive for L. donovani infection with rK39 strip test. Of the six randomly selected dogs tested with Modified Giemsa’s stained of impression smears of spleen and liver showed 2 (33.33%) positive whereas PCR technique detected 5 (83.33%) positive for L. donovani. Results of PCR showed 145bp amplicon, specific for L. donovani infection in 83.33% stray dogs. Conclusions: This study reveals that a high percentage of L. donovani asymptomatic carrier infections occur in dogs and evidence indicates that dogs and humans may potentially serve as a source of infection to sand fly vectors and accordingly dogs can be recognized as a probable animal reservoir for the Leishmania infection in the endemic region in Bangladesh. However, further studies are required to determine the ability of dogs to transmit the L. donovani to the vector sand fly in nature and its evidence on ‘One Health’ perspectives. Keywords: Visceral leishmaniasis, Endemic region, Stray dogs, rK39 strip test, Giemsa’s stained liver and spleen impression smears, PCR, Reservoir host, Mymensingh

scholarly journals Cutaneous Leishmaniasis in Algeria; Highlight on the Focus of M’Sila

2021 ◽  
Vol 9 (5) ◽  
pp. 962
Author(s):  
Razika Beniklef ◽  
Karim Aoun ◽  
Karim Boudrissa ◽  
Meriem Ben Abid ◽  
Kamel Cherif ◽  
...  
Keyword(s):  
Risk Factors ◽  
Visceral Leishmaniasis ◽  
Cutaneous Leishmaniasis ◽  
Leishmania Infantum ◽  
Psammomys Obesus ◽  
Phlebotomus Papatasi ◽  
Wild Rodents ◽  
High Incidence ◽  
Medical Importance ◽  
Underlying Risk

Algeria ranks second after Afghanistan for the incidence of cutaneous leishmaniasis (CL) worldwide. Here, we report a 34-years retrospective analysis of CL in Algeria and focused on the most affected region, the M’Sila province. All 66 cutaneous isolates corresponded to Leishmania (L.) major. Our study of the sandfly and rodent fauna further highlighted the high density of Phlebotomus papatasi and additional phlebotomine species of medical importance, not previously identified in M’Sila. Wild rodents belonging to nine species were trapped in M’Sila, and Psammomys obesus and Meriones shawi were found infected by L. major. In addition, Leishmania infantum was isolated from two visceral leishmaniasis cases, one dog and its proven vectors (P. perniciosus, P. longicuspis, and P. perfiliewi) inventoried during the survey. The high incidence of CL in the M’Sila province is likely a consequence of the increase in minimum temperatures recorded that constitutes suitable conditions for establishing a high endemicity and leads to an explosive rise in leishmaniases cases in this region. A thorough investigation of the underlying risk factors is urgently needed to detect new cases earlier. All these would improve the preparedness to fight the disease.

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