Ecological niches and blood sources of sand fly in an endemic focus of visceral leishmaniasis in Jiuzhaigou, Sichuan, China

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

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Exploring sand fly salivary proteins to design multiepitope subunit vaccine to fight against visceral leishmaniasis

International Journal of Infectious Diseases ◽

10.1016/j.ijid.2020.09.1248 ◽

2020 ◽

Vol 101 ◽

pp. 477

Author(s):

R. Pandey ◽

V.K. Prajapati

Keyword(s):

Visceral Leishmaniasis ◽

Subunit Vaccine ◽

Sand Fly ◽

Salivary Proteins

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Clinical and laboratory profiles of visceral leishmaniasis among adult patients admitted to Felege Hiwot Hospital, Bahir Dar, Ethiopia

SAGE Open Medicine ◽

10.1177/20503121211036787 ◽

2021 ◽

Vol 9 ◽

pp. 205031212110367

Author(s):

Berhanu Tarekegn ◽

Ayanaw Tamene

Keyword(s):

Visceral Leishmaniasis ◽

Leishmania Donovani ◽

Clinical Presentation ◽

Winter Season ◽

Adult Patients ◽

Sand Fly ◽

Timely Initiation ◽

Vector Borne Disease ◽

Vector Borne ◽

Endemic Areas

Background: Visceral leishmaniasis is a vector-borne disease caused by Leishmania donovani transmitted by sand fly species. It is the third most common vector-borne disease globally. Visceral leishmaniasis is endemic in Ethiopia with an estimated annual incidence ranging from 3700 to 7400 cases. This research aimed to assess the clinical presentations and laboratory profiles of visceral leishmaniasis for early diagnosis and timely initiation of management. Objective: To describe the clinical and laboratory manifestation and diagnostic modalities of visceral leishmaniasis among adult patients admitted to Felege Hiwot Hospital, from 1 September 2016 to 30 August 2019. Method: Institution-based retrospective cross-sectional study was conducted among 141 patients admitted to Felege Hiwot Hospital from 1 September 2016 to 30 August 2019. Descriptive statistics were used to describe the clinical presentation and laboratory profiles of patients with visceral leishmaniasis. Results: Among a total of 141 enrolled patients in the study, males were affected 13-fold. Most of them were travelers to endemic areas during the winter season for labor work. The mean duration of illness was 48 days. Common symptoms were fever (96.5%), weightless (82.5%), jaundice (18.4%), vomiting/diarrhea (13.5%), and bleeding episodes (11.3%). Splenomegaly was seen in 98.6%, ascites in 35.5%, and lymphadenopathy in 9.9%. Lymphadenopathy was seen significantly in HIV patients (40%). Anemia was seen in 95%, thrombocytopenia in 90.2%, leukopenia in 86.4%, and pancytopenia in 79.4%. Half of the patients had coinfection. Neutropenic sepsis was seen in 21.3%. The diagnosis was made by tissue aspiration in 65% of patients. Conclusion: The majority of patients who were diagnosed to have visceral leishmaniasis were young male adults who traveled to the endemic areas seasonally. Fever and splenomegaly were seen as the commonest clinical presentation. Lymphadenopathy occurred in high frequency among HIV co-infected patients. Anemia was the commonest hematologic finding.

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Visceral leishmaniasis (Kala-azar) in Qom Province, Iran: Report of two cases

F1000Research ◽

10.12688/f1000research.15805.1 ◽

2018 ◽

Vol 7 ◽

pp. 1371

Author(s):

Leyli Zanjirani Farahani ◽

Abedin Saghafipour ◽

Mehdi Mohebali ◽

Behnaz Akhoundi ◽

Hedayatollah Raufi

Keyword(s):

Visceral Leishmaniasis ◽

Rural Areas ◽

Control Strategies ◽

Sand Fly ◽

Recurrent Fever ◽

Kala Azar ◽

Periodic Monitoring ◽

History Of ◽

The Common

Visceral leishmaniasis (VL) is a fatal parasitic zoonotic worldwide disease, which transmits to humans by the infected Phlebotomine sand fly bite. The common form of VL in Iran is the Mediterranean type with the causative agent of Leishmania infantum, whose main reservoirs are stray and domesticated dogs. The disease has several endemic foci in Iran, mostly seen among children under the age of 10, living in rural areas and nomadic tribes. The first cases of Kala-Azar in Qom province, central Iran, were reported in the year 2001, from the villages of Ghahan district. After conducting VL control strategies in the area, no new cases of the disease had been reported until recently. The cases described here are two 2-year-old girls, living in the urban parts of Qom province, one of whom did not have a history of traveling to known endemic areas of the disease. The patients were admitted to hospital in 2016-2017, complaining from recurrent fever with unrecognized reason, associated with decreased appetite and weight loss. Disease follow-up demonstrated anemia and splenomegaly, which led to diagnosis of VL, and both patients are now fully recovered. VL was presumed to be controlled in Qom province but the present cases indicate that possible VL existence remains in the region. Therefore, urgent studies and periodic monitoring are needed to identify potential reservoirs of VL in the area.

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Larval Microhabitats of Lutzomyia longipalpis (Diptera: Psychodidae) in an Endemic Focus of Visceral Leishmaniasis in Colombia

Journal of Medical Entomology ◽

10.1093/jmedent/34.6.719 ◽

1997 ◽

Vol 34 (6) ◽

pp. 719-728 ◽

Cited By ~ 23

Author(s):

Cristina Ferro ◽

Raul Pardo ◽

Mariela Torres ◽

Amy C. Morrison

Keyword(s):

Visceral Leishmaniasis ◽

Lutzomyia Longipalpis ◽

Endemic Focus

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Entomological Studies in Itaúna, Brazil, an Area With Visceral Leishmaniasis Transmission: Fauna Survey, Natural Leishmania Infection, and Molecular Characterization of the Species Circulating in Phlebotomine Sand Flies (Diptera: Psychodidae)

Journal of Medical Entomology ◽

10.1093/jme/tjz061 ◽

2019 ◽

Vol 56 (5) ◽

pp. 1368-1376 ◽

Cited By ~ 4

Author(s):

Josiane V Lopes ◽

Erika M Michalsky ◽

Nathalia C L Pereira ◽

Adão J V de Paula ◽

Fabiana O Lara-Silva ◽

...

Keyword(s):

Visceral Leishmaniasis ◽

Natural Infection ◽

Local Population ◽

Influential Factor ◽

Sand Fly ◽

Health Concern ◽

Leishmania Infection ◽

Lutzomyia Longipalpis ◽

Sand Flies ◽

Phlebotomine Sand Flies

Abstract Among neglected tropical diseases, visceral leishmaniasis (VL) shows great relevance in global terms and is a serious public health concern due to the possibility of severe and lethal forms in humans. In this study, we evaluate entomological factors such as diversity and abundance of phlebotomine sand flies (Diptera:Psychodidae) and the Leishmania species circulating in these species in possible association with VL transmission in the Brazilian town Itaúna. The entomological collections were performed during three consecutive nights, always in the third week of each month, within a period of 12 mo. A total of 1,786 sand fly specimens were collected, from which 20% were collected inside houses. The influence of three local climatic variables (temperature, rainfall, relative humidity) on the population sizes of these insects was evaluated. Temperature was the most influential factor, with a significant positive correlation with the local population size of phlebotomine sand flies collected per month. Lutzomyia longipalpis (Lutz & Neiva, 1912) was the predominant species in the study area. Leishmania DNA was detected in nine out of 133 pools of sand fly females, using nested/PCR, which resulted in a minimal natural infection rate of 2.91%. DNA from Leishmania infantum Nicolle, 1908 (Kinetoplastida: Trypanosomatida), was detected in Evandromyia cortelezzii (Bréthes, 1923), Ev. evandroi (Costa, Lima & Antunes, 1936), Ev. lenti (Mangabeira, 1938), and Ev. termitophila (Martins, Falcão & Silva, 1964), besides Lu. longipalpis. Our study indicates favorable conditions for VL spreading in Itaúna due to the presence of Lu. longipalpis and Le. infantum-infected phlebotomine sand flies.

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Recalibration of insecticide-measuring containers could prevent underdosing of insecticide during indoor residual spraying for visceral leishmaniasis (kala-azar) elimination in India

Transactions of the Royal Society of Tropical Medicine and Hygiene ◽

10.1093/trstmh/traa026 ◽

2020 ◽

Vol 114 (7) ◽

pp. 549-552

Author(s):

Suman Saurabh ◽

Ravindra Kumar Yadav

Keyword(s):

Visceral Leishmaniasis ◽

Vector Control ◽

Indoor Residual Spraying ◽

Sand Fly ◽

Kala Azar ◽

Elimination Programme

Abstract Background The visceral leishmaniasis (kala-azar) elimination programme in India relies on indoor residual spraying (IRS) for sand-fly vector control. Insecticide supplied by a new manufacturer was introduced for IRS in 2019. We aimed to explore whether this led to a change in insecticide quantity being used in the field. Methods We compared measurements of weights of 250 mL of insecticide powder of two different manufacturers using a certified and calibrated weighing instrument. Results The density of insecticide supplied in 2019 was 43.4% lower than that in 2018, thereby leading to underdosing during current IRS activity. Conclusions Insecticide-measuring containers should be recalibrated prior to every IRS round and also when an insecticide manufacturer changes, so that the insecticide dose is maintained within the recommended range.

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