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

Author(s):  
M. A. Hossen

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

2020 ◽  
Author(s):  
Subir Karmakar ◽  
Nevien Ismail ◽  
Fabiano Oliveira ◽  
James Oristian ◽  
Wen Wei Zhang ◽  
...  

AbstractVisceral Leishmaniasis (VL) is fatal if untreated. There is no licensed vaccine available against human leishmaniasis. We recently demonstrated protection in mice against L. major infection using a CRISPR genome edited attenuated Leishmania major strain (LmCen−/−). Here, as a pre-clinical step, we evaluated the protective efficacy of LmCen−/− against VL induced by sand fly transmitted Leishmania donovani in hamsters. Intradermal immunization of hamsters with LmCen−/− did not develop any lesion; while still priming a pro-inflammatory immune response. When challenged with L. donovani either by intradermal needle injection or by infected sand flies, LmCen−/−-immunized hamsters were protected, not showing spleen or liver pathology averting VL fatality compared to control animals. Spleen cells from LmCen−/− immunized and infected sand fly challenged hamsters produced significantly higher Th1-associated cytokines and chemokines including IFN-γ and TNF-α, and significantly reduced expression of the anti-inflammatory cytokines IL-10 and IL-21, compared to non-immunized challenged animals. We further developed a GLP-grade LmCen−/− which showed equal protection as laboratory-grade LmCen−/− parasites in hamsters. Importantly, GLP-grade LmCen−/− parasites also induced a proinflammatory immune response in the PBMCs isolated from healthy people living in non-endemic and endemic for VL as well as cured VL people living in endemic region. Together, this study demonstrates that the LmCen−/− parasites are safe and efficacious against VL and it is a strong candidate vaccine to be tested in a human clinical trial.


2012 ◽  
Vol 10 (1) ◽  
pp. 79-86 ◽  
Author(s):  
S Akter ◽  
M Z Alam ◽  
M T Islam ◽  
M M H Mondal

To study the effect of months, seasons, age and sex on visceral leishmaniasis (VL) in human, data were collected   during March 2010 through February 2011 from the register book of Upazila Health Complex (UHC) of Trishal, which  is an endemic region for VL in the Mymensingh district. Besides, 70 blood samples were collected from suspected VL   human patients to compare microscopy with rK39 immunochromatographic strip test. Additionally, 50 cattle blood samples were also collected from houses with active or recently-treated VL patients to determine the possible animal   reservoir of VL through rK39 strip test. Of the suspected VL patients in the UHC registered book, 43.8% were seropositive. The percentages of seropositive cases were higher in September (73.3%), November (67.2%) and   August (65.5%) than in May (18.5%), June (27.5%) and March (36.7%). The rainy season (58.4%) and the winter   season (50.6%) showed higher seropositive than the summer (30.7%) season which was significant (p? 0.001).   Hospital cases of VL were significantly (p?0.05) higher in 3-14 years (49.3%) and 15-45 years (43.5%) than in children <3 years (32.1%) and adults aged >45 years (33.6%) people. The estimated sensitivity of rK39 strip test and   microscopic examination were 100% and 58.8%, respectively and the specificity were 72% and 100%, respectively. Only two cattle blood samples were found positive to rK39 strip test. Our present study indicates that rK39 strip test is   superior to the diagnosis of VL compared with parasitological confirmation by direct microscopy of the peripheral   blood. Further works are needed to focus on molecular approaches for diagnosis and epidemiological study of VL, sand flies investigation and to confirm the cattle as animal reservoir for VL transmission.   DOI: http://dx.doi.org/10.3329/jbau.v10i1.12097   J. Bangladesh Agril. Univ. 10(1): 79–86, 2012    


2013 ◽  
Vol 55 (2) ◽  
pp. 101-104 ◽  
Author(s):  
Luciana Almeida Silva ◽  
Héctor Dardo Romero ◽  
Aline Fagundes ◽  
Nédia Nehme ◽  
Otávio Fernandes ◽  
...  

The diagnosis of asymptomatic infection with Leishmania (Leishmania) chagasi has become more important over recent years. Expansion of visceral leishmaniasis might be associated with other routes of transmission such as transfusion, congenital or even vector transmission, and subjects with asymptomatic infection are potential reservoirs. Moreover, the identification of infection may contribute to the management of patients with immunosuppressive conditions (HIV, transplants, use of immunomodulators) and to the assessment of the effectiveness of control measures. In this study, 149 subjects living in a visceral leishmaniasis endemic area were evaluated clinically and submitted to genus-specific polymerase chain reaction (PCR), serological testing, and the Montenegro skin test. Forty-nine (32.9%) of the subjects had a positive PCR result and none of them developed the disease within a follow-up period of three years. No association was observed between the results of PCR, serological and skin tests. A positive PCR result in subjects from the endemic area did not indicate a risk of progression to visceral leishmaniasis and was not associated with a positive result in the serological tests.


2019 ◽  
Vol 56 (5) ◽  
pp. 1368-1376 ◽  
Author(s):  
Josiane V Lopes ◽  
Erika M Michalsky ◽  
Nathalia C L Pereira ◽  
Adão J V de Paula ◽  
Fabiana O Lara-Silva ◽  
...  

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.


2013 ◽  
Vol 88 (2) ◽  
pp. 222-226 ◽  
Author(s):  
Dharmendra Singh ◽  
Neena Verma ◽  
Sushmita Das ◽  
Vidya Nand Rabi Das ◽  
Pradeep Das ◽  
...  

2017 ◽  
Vol 5 (1) ◽  
pp. 430-441
Author(s):  
Belal Abdallah A. Adam ◽  
Moawia Mukhtar Hassan ◽  
Osman Mohammed Abd Elnour ◽  
Ahmed Hamid Awadallah

Visceral leishmaniasis (VL; kala-azar) is one of the most important parasitic tropical diseases in Sudan   and the Sudan is considered to be one of the most important foci in the world. The visceral leishmaniasis has been described in Sudan since the beginning of the twentieth century. In Sudan, VL is caused by Leishmania donovani complex: MON 18, MON 30 and MON 82 zymodemes and  The proven vector is Phlebotomus (Larroussius) orientalis, in this study a survey was carried out to identify the principal vector of VL based on Leishmania infection, morphological characters and to determine some ecological aspects of the sand flies prevalent in the area . Ten species of sand flies were recorded, three Phlebotomus species and seven Sergentomyia species of these sandflies, P. rodhaini was collected only from Acacia seyal/Balanities aegyptiaca at the Island whereas S. hunti was collected from the Acacia nilotica forest only of the total collections, P. orientalis representing 3.80% (248 specimens) of the total collection and P. papatasi were 3.11% of the collection. Sand flies identification was done under a binocular microscope at 40x (magnification). The main features used for sand flies identification were the sperm theca of the female, the termination of the male and the pharyngeal and the ciboria toothed structures of both sexes. According to results of this study we recommended the following:  more studies are needed in the future to determine the transmission season, and infection rates of Leishmania parasites in human and the animal host in this area. Annually Entomological surveys must be done to determine density of Sand fly Vectors and Encourage the use of personal protection tools (ITNs), repellents, and improving of houses to avoid bite of sand fly.


Author(s):  
Anna Maria da Cruz Ferreira Evaristo ◽  
Andreina de Carvalho Araujo ◽  
Andréa Pereira da Costa ◽  
Kamila Gaudêncio da Silva Sales ◽  
José Alexandre Menezes da Silva ◽  
...  

Abstract The aim of this study was to investigate the level of exposure to Leishmania infection in stray dogs in an area of intense visceral leishmaniasis transmission in the state of Pernambuco, Brazil. Blood samples from 178 dogs were analyzed using serological and molecular assays: rapid immunochromatographic test (ICT), enzyme-linked immunosorbent assay (ELISA), immunofluorescence antibody test (IFAT), and conventional and quantitative polymerase chain reaction (cPCR and qPCR). Positivity values obtained with serological tests were 71.4% (127/178), 70.2% (125/178), and 50.6% (90/178) using ICT, ELISA, and IFAT, respectively, with 38.8% (69/178) of the dogs were simultaneously positive for all three tests. The positivity values obtained with cPCR and qPCR were 20.2% (36/178) and 38.8% (69/178), respectively, with 11.8% (21/178) testing positive in both molecular assays. Overall, 87.1% (155/178) were positive for anti-Leishmania spp. antibodies and/or Leishmania spp. DNA. Positivity to one or more tests was statistically associated with lymphadenomegaly, skin lesions, lymphocytosis, anemia and hyperproteinemia. The results of this study revealed a high level of exposure to Leishmania in stray dogs in an area of intense human visceral leishmaniasis transmission, suggesting that dogs play a role as reservoirs in the transmission cycle of this zoonosis.


2018 ◽  
Vol 27 (4) ◽  
pp. 570-574 ◽  
Author(s):  
Fernanda Morcatti Coura ◽  
Stephanie Karoline Pereira Passos ◽  
Marina de Oliveira França Pelegrino ◽  
Fabiola de Oliveira Paes Leme ◽  
Gustavo Fontes Paz ◽  
...  

Abstract The role of cats in the epidemiological cycle of leishmaniasis remains unclear. To better understand the occurrence of leishmaniasis in cats, we studied the frequency of Leishmania in serum samples of 100 cats living in an endemic region for canine and human leishmaniasis by serological, parasitological, and molecular methods. Of the 100 cats, 54 were seropositive for Leishmania antibodies by immunofluorescence antibody test. None of the bone marrow aspirates collected from these cats tested positive for the parasite in culture or upon polymerase chain reaction (PCR) analysis. Biopsy samples of the ears also tested negative for Leishmania upon PCR analysis. These findings may indicate that the region is endemic for canine leishmaniasis and cats are infected by Leishmania; or that cross-reaction with antibodies against other parasites increases the frequency of seropositivity; or that cats respond to Leishmania infection by producing antibodies when few or no parasites are present in bone marrow and tissue samples. Overall, our results suggest that cats can be infected by Leishmania ; however, we failed to demonstrate feline parasitosis. These findings highlight the need to study leishmaniasis in cats, since sandflies feed on cats, these animals may act as a reservoir for the parasite.


2020 ◽  
Author(s):  
Sophie Owen ◽  
Faria Hossain ◽  
Prakash Ghosh ◽  
Rajashree Chowdhury ◽  
Md. Sakhawat Hossain ◽  
...  

AbstractBackgroundAsymptomatic Leishmania infections outnumber clinical infections on the Indian sub-continent (ISC) where disease reservoirs are anthroponotic. Diagnostics which detect active asymptomatic infection, which are suitable for monitoring and surveillance, may be of benefit to the visceral leishmaniasis (VL) elimination campaign on the ISC.Methodology/Principal FindingsQuantitative polymerase chain reaction (qPCR), loop mediated isothermal amplification (LAMP), the direct agglutination test (DAT), and the Leishmania antigen ELISA were carried out on blood and urine samples collected from 720 household and neighbouring contacts of 276 VL and post kala-azar dermal leishmaniasis (PKDL) index cases, with no symptoms or history of VL and PKDL, in endemic regions of Bangladesh between September 2016 and March 2018. Of the 720 contacts of index cases, asymptomatic infection was detected in 69 (9.6%) participants by a combination of qPCR (1.0%), LAMP (2.1%), DAT (3.9%), and Leishmania antigen ELISA (3.3%). Only 1 (0.1%) participant was detected positive by all 4 diagnostic tests. Poor agreement between tests was calculated using Cohen’s kappa (k) statistics, however the Leishmania antigen ELISA and DAT in combination capture all participants positive by more than one test. We find strong evidence for association between the index case being a PKDL case (OR 1.94, p = 0.009), specifically macular PKDL (OR 2.12, p = 0.004) and being positive for at least one of the four tests.Conclusions/SignificanceLeishmania antigen ELISA detects active asymptomatic infection, requires a non-invasive sample, and therefore may be of benefit for monitoring transmission and surveillance in an elimination setting in combination with serology. Development of an antigen detection test in RDT format would be of benefit to the elimination campaign.Author summaryInfection with the parasite Leishmania donovani can lead to an asymptomatic infection with only around 5% of asymptomatics converting to visceral leishmaniasis the clinical manifestation of the infection. Serological assays detect anti-Leishmania antibodies and therefore cannot distinguish between past and active infection. Molecular assays and those which detect Leishmania antigens detect active infection. Since the signing of a memorandum of understanding in 2005, visceral leishmaniasis has been targeted for elimination in India, Nepal and Bangladesh. In an elimination setting such as Bangladesh, where disease reservoirs are anthroponotic, a relatively simple test such as the Leishmania antigen ELISA which requires a non-invasive urine sample, may be of benefit in combination with serology for surveillance and monitoring of Leishmania transmission. Development of an antigen test into a field compatible rapid diagnostic test would be of further benefit to the elimination campaign.


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