Search

Over the last decade, the incidence of visceral leishmaniasis (VL) has increased in many districts of the province of Fars, in southern Iran. Recent epidemiological reports indicate that asymptomatic human infections with Leishmania infantum (the causative agent of VL throughout the Mediterranean basin) occur more frequently in Iran than was previously believed. Between 2004 and 2006, blood samples were collected from 802 apparently healthy subjects from communities, in the north-west and south-east of Fars province, where VL cases had been recorded. Each of these samples was tested for anti-Leishmania antibodies, in direct agglutination tests (DAT), and for L. infantum kinetoplast DNA, in PCR-based assays. Of the 426 subjects from north-western Fars, eight (1.9%) were found seropositive and 68 (16.0%) PCR-positive. The corresponding values for the 376 subjects from south-eastern Fars were lower, with five (1.3%) seropositive and 32 (8.5%) PCR-positive. Of the 100 PCR-positive subjects, 18 (18.0%) each lived in a household in which there had been a case of VL, and six (6.0%) had had VL themselves (in each case, more than a year before the blood sampling for the present study). Although 21 of the PCR-positives have now been followed-up for at least 18 months, none has developed symptomatic VL. Since positivity in the PCR-based assay probably indicated the presence of L. infantum amastigotes in the peripheral blood of 12.5% of the subjects, it is clear that asymptomatic human carriers of L. infantum are quite common in the study areas and probably act as reservoirs in the transmission of the parasite, to humans and to dogs, by sandflies. [ABSTRACT FROM AUTHOR]

Cases of human visceral leishmaniasis (VL) are often found to have bacterial infections. Between 1997 and 2007, 60 cases of VL were admitted to the paediatric ward of the Afzalipour Medical Centre, which forms part of the Kerman University of Medical Sciences, in southern Iran. On admission, the 60 cases (39 boys and 21 girls), each of which was confirmed by the demonstration of amastigotes in a bone-marrow aspirate, had a mean (S.D.) age of 48.8 (44.4) months and a mean (S.D.) erythrocyte sedimentation rate of 53.2 (34.2) mm/h. Twenty-five (42%) of the cases (14 boys and 11 girls) were found to have bacterial infections. Urinary infections (seen in 36% of the cases with bacterial infection) were the most common, followed by blood (28%), respiratory (16%), gastro-intestinal (12%) and skin infections (8%). Despite treatment of all the VL cases with meglumine antimoniate, four (7%) died on the paediatric ward, all four having concurrent bacterial infections. The leucopenia and immunosuppression associated with VL probably facilitate the development of fatal bacterial co-infections. The prompt diagnosis and treatment of both the VL and any bacterial co-infections should therefore reduce mortality among VL cases. [ABSTRACT FROM AUTHOR]

The incidence of human visceral leishmaniasis (VL) caused by Leishmania infantum, which is endemic in several parts of Iran, has recently increased in the Nourabad-Mamassani district of Fars province, in the south of the country. Between 2003 and 2005, 12,688 sandflies were caught in this focus, using CDC miniature light traps, sticky traps and aspirators, in an attempt to identify the main vector of L. infantum. When 120 of the parous, female Phlebotomus (Paraphlebotomus) alexandri caught were individually checked for Leishmania infection, in an assay based on PCR and kinetoplast minicircle primers (LINR4 and LIN17), five (4.2%) of the flies were found to be infected with L. infantum. Thirty-nine (32.5%) of the 120 blood-fed Ph. alexandri checked in an ELISA were found positive for human blood. Since Ph. alexandri was the third-most common species caught (representing over 17% of the total catch), was clearly anthropophilic, and was not infrequently infected with L. infantum, it is probably an important vector in the Nourabad-Mamassani focus. Although other sandfly species have been found naturally infected with promastigotes in Iran, Ph. alexandri is the first that has been proven to harbour L. infantum in the country. [ABSTRACT FROM AUTHOR]