ABSTRACT
Background: Leishmaniasis is a regional infectious disease caused by the bite of Leishmania-carrying sandflies. The clinical symptoms include prolonged fever, spleen enlargement, anemia, emaciation, leukopenia, and increased serum globulin levels. If not appropriately treated, patients may die of complications caused by leishmaniasis within 1-2 years after the onset of the illness. Therefore, further investigation of the mechanisms of infection by this pathogen is required. Here, an epidemiological study of Leishmania carriers was conducted. The potential mechanism of infection through domestic animals as carriers of the parasite was investigated to identify potential reservoir hosts for Leishmania. Methods: The rK-39 strip test was performed on blood samples from previously infected patients. Blood samples were collected from the patients and their families. The blood, liver, spleen, and diaphragm muscle samples were collected from livestock. To perform nested polymerase chain reaction (PCR), DNA was extracted and the internal transcribed spacer sequence was used. The amplified products were then subjected to restriction fragment length polymorphism and phylogenetic analyses. Results: Among previously infected patients, 40% (12/30) showed positive results in the rK-39 strip test. The nested PCR positive rates for previously infected patients/relatives and livestock samples were 86% (77/90) and 80% (8/10), respectively. Moreover, the phylogenetic analysis showed that the pathogen was Leishmania infantum. Dogs, patients, and domesticated animals carrying Leishmania were found to be a potential source of infection for leishmaniasis. Conclusions: The results of this study provide a basis for developing disease prevention and control strategies for leishmaniasis.
Subject(s)
Leishmania infantum , Leishmaniasis , Psychodidae , Animals , China , Dogs , Humans , PhylogenyABSTRACT
Few outbreaks of the desert sub-type of zoonotic visceral leishmaniasis (VL) have been described worldwide. In 2008, the incidence rate of VL in Jiashi County, Xinjiang Uygur Autonomous Region in the western part of the People's Republic of China, increased more than twenty-folds compared to the average annual incidence rate. The majority of the cases (96.6%) occurred among <2 year-old infants. For the first time in the desert area of Xinjiang, the parasites were isolated from bone marrow aspirates, using the NNN medium culture approach. The genetic analysis of the ITS-1 nucleotide sequence indicated that three isolates from eastern Jiashi County were genetically closely related and belonged to the Leishmaniainfantum group. However, they differed from an isolate from Kashi city which was classified as a member of the Leishmaniadonovani group.
Subject(s)
Desert Climate , Disease Outbreaks , Leishmania donovani/isolation & purification , Leishmania infantum/isolation & purification , Leishmaniasis, Visceral/epidemiology , Zoonoses/epidemiology , Animals , Child, Preschool , China/epidemiology , DNA, Ribosomal Spacer/analysis , Female , Humans , Infant , Infant, Newborn , Leishmania donovani/classification , Leishmania donovani/genetics , Leishmania infantum/classification , Leishmania infantum/genetics , Leishmaniasis, Visceral/parasitology , Male , Molecular Sequence Data , Sequence Analysis, DNA , Zoonoses/parasitologySubject(s)
Amphotericin B/therapeutic use , Antiprotozoal Agents/therapeutic use , Leishmania donovani/drug effects , Leishmaniasis, Visceral/drug therapy , Adult , Amphotericin B/pharmacology , Animals , Antimony Sodium Gluconate/pharmacology , Antimony Sodium Gluconate/therapeutic use , Antiprotozoal Agents/pharmacology , Drug Resistance , Humans , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/parasitology , Male , Treatment OutcomeABSTRACT
OBJECTIVE: To analyze the status of Leishmania infantum asymptomatic infection in human population of a Kala-azar endemic area in Wenxian County, Gansu Province, and to evaluate the tests used. METHODS: Blood samples were tested by PCR using two pairs of primers, RV1-RV2 and K13A-K13B, for detecting Leishmania-specific DNA. ELISA and rK39-dipstick were used to detect Leishmania-specific antibodies. RESULTS: The positive rate of PCR, ELISA and rK39-dipstick was 30.9%(83/269). 24.2%(65/269) and 0 (0/269) respectively. CONCLUSION: The prevalence of asymptomatic infection of L. infantum in humans is high in the area. PCR test based on RV1-RV2 and K13A-K13B primer pairs is a sensitive and specific method for detecting the asymptomatic infection.
