Seroprevalence of Leishmania infection among the healthy blood donors in kala-azar endemic areas of Iran.

Visceral leishmaniasis (VL) is a serious health problem in Iran. The disease is mainly transmitted by sand fly bites, but its transmission through transfusion in endemic areas may also occur. The current study aimed to determine the prevalence of Leishmania infection among blood donors in VL-endemic areas in south of Iran. A total of 2003 healthy blood donors from blood service centers in five VL-endemic districts in Fars province, southern Iran, were enrolled in the study. The blood samples were assessed for antibodies against Leishmania infantum by direct agglutination test (DAT). Seropositive subjects were tested for the presence of L. infantum DNA in their buffy coat by the molecular method. Socio-demographic features of the subjects were also documented during sample collecting. The mean age of participants was 36.3 (SD = 10.7 years). Male constituted 94.7 % of the subjects while only 5.3 % of donors were female. Twenty-eight blood donors (1.4 %) were positive for Leishmania infection by DAT. Only one of these seropositive donors was positive for Leishmania infection by polymerase chain reaction. A significant correlation was found between age, the place of residence and seropositivity to Leishmania (P < 0.05). Findings of this study revealed that the prevalence of Leishmania infection among blood donors in transfusion centers in the VL-endemic areas in Iran is relatively high. These asymptomatic blood donors may constitute a risk of transmitting of VL to susceptible recipients.

Toxoplasma seroepidemiology in women who intend to marry in Jahrom, Islamic Republic of Iran.

Infection with Toxoplasma gondii during pregnancy can lead to severe fetal sequelae. This cross-sectional study aimed to determine T. gondii seropositivity among a sample of young women in Jahrom, Islamic Republic of Iran. Four hundred and three young women with a mean age of 20.3 years who presented for pre-marriage laboratory testing were entered in the study. T. gondii antibodies (IgG and IgM) were measured using ELISA. Of the 403 women, 15% were seropositive for T. gondii antibodies (13% for IgG and 2% for IgM). Seropositivity for T. gondii IgG differed according to age groups but there was no significant difference (P = 0.83). IgM seropositivity showed the highest rate among women aged < 20 years. Many young women in Jahrom Province are susceptible to primary toxoplasmosis during pregnancy, therefore, appropriate educational programmes to improve knowledge in this population should be implemented to prevent toxoplasmosis-related congenital malformations.

Toxoplasma seroepidemiology in women who intend to marry in Jahrom, Islamic Republic of Iran

Infection with Toxoplasma gondii during pregnancy can lead to severe fetal sequelae. This cross-sectional study aimed to determine T. gondii seropositivity among a sample of young women in Jahrom, Islamic Republic of Iran. Four hundred and three young women with a mean age of 20.3 years who presented for pre-marriage laboratory testing were entered in the study. T. gondii antibodies [IgG and IgM] were measured using ELISA. Of the 403 women, 15% were seropositive for T. gondii antibodies [13% for IgG and 2% for IgM].Seropositivity for T. gondii IgG differed according to age groups but there was no significant difference [P = 0.83]. IgM seropositivity showed the highest rate among women aged < 20 years. Many young women in Jahrom Province are susceptible to primary toxoplasmosis during pregnancy, therefore, appropriate educational programmes to improve knowledge in this population should be implemented to prevent toxoplasmosis-related congenital malformations

First microscopical and molecular-based characterization of Leishmania major within naturally infected Phlebotomus salehi (Diptera; Psychodidae) in Fars province, southern Iran.

Zoonotoc cutaneous leishmaniasis is endemic in several parts of Iran. Jahrom district is one of the most important endemic foci of leishmaniasis located in Fars province, southern Iran. To identify the vectors of leishmaniasis in this area, a total of 349 sandflies were collected during May to August 2009. They were caught from outdoors in five regions of Jahrom district including villages of Mousavieh, Ghotb-Abad, Heydar-Abad, Fath-Abad and Jahrom County. Eleven species of Phlebotomine (three Phlebotomus spp. and eight Sergentomyia spp.) were detected. To determine the sandflies naturally infected by Leishmania spp., 122 female sandflies were dissected and evaluated microscopically using Giemsa-stained slides. Natural infection of 2 out of 38 (5.26%) P. papatasi and 1 out of 8 (12.5%) P. salehi to Leishmania major was confirmed in the region. Sequencing and nested polymerase chain reaction-based detection of Leishmania were carried out to confirm the microscopic findings. Five (13.16%) P. papatasi and two (25%) P. salehi were positive in nested polymerase chain reaction assay. All positive samples were shown 72-76% similarity with L. major Friedlin. On the basis of our knowledge, this is the first molecular detection of L. major within naturally infected P. salehi in this region in southern Iran.

The changing profile of cutaneous leishmaniasis in a focus of the disease in Jahrom district, southern Iran.

Human cutaneous leishmaniasis (CL) is endemic in several parts of Iran, and there is an urban focus of the disease in the district of Jahrom, which forms part of the southern province of Fars. To explore the current profile of the disease in Jahrom district, samples were taken from the skin lesions of 40 cases of CL patients in the district, so that the causative parasites could be identified, to species, in a nested PCR. Although Leishmania tropica has been identified, in the past, as the cause of most of the urban CL in Fars province, the predominant species represented in the recent samples from Jahrom district was L. major (87.5%), while L. tropica was relatively rare (12.5%). More than one in every three (35%) of the cases examined was a child aged <10 years. The most common location of the skin lesions was on the hands. Although most of the cases had one skin lesion each, two cases each had >25 such lesions. The change in the predominant parasite causing CL in Jahrom district, from the L. tropica usually associated with the urban disease in Iran to the L. major more usually associated with CL in rural settings, may well necessitate changes in the local strategies for the prevention and control of CL.

Cryptosporidium infection in major histocompatibility complex congeneic strains of mice: variation in susceptibility and the role of T-cell cytokine responses.

Studies with murine infection models have shown that immunity to the protozoan parasite Cryptosporidium involves T-cells and interferon-gamma (IFN-gamma) activity. The present study was performed to compare the course of infection of Cryptosporidium muris in major histocompatibility complex (MHC) congeneic strains of mice and examine the relationship between susceptibility to infection and production of T-cell cytokines. In experiments with BALB mice, the BALB/c strain (H-2d) produced significantly fewer oocysts and recovered from infection sooner than the BALB/B (H-2b) or BALB/K (H-2k) strains. BALB/B X BALB/c F1 hybrid mice were found to express the more susceptible phenotype of the BALB/B parent strain, indicating that the gene(s) in the H-2 locus conferring increased susceptibility to C. muris infection was dominant. At different times during infection of the resistant BALB/c strain and the susceptible BALB/B strain, splenocytes were cultured with soluble parasite antigen and measurements were made of production of a number of T-cell cytokines. Similar patterns of increasing levels of IFN-gamma and interleukin 2 (IL-2) were observed in both the resistant and susceptible strains during the patent stage of infection, indicating that production of these type 1 T-helper-cell (TH1) cytokines (i.e. involved in cell-mediated responses) correlated with the development of immunity. This also suggested that the increased susceptibility of BALB/B mice was not associated with a defective TH1 cytokine response. In the study of TH2 cytokines (involved in induction of an antibody response), low levels of IL-10 were detected during infection of BALB/c and BALB/B mice. In contrast, although IL-4 was released by splenocytes of both strains, significantly larger amounts were obtained from cells of the susceptible BALB/B mice in the early stages of infection. Thus, the H-2-dependent variation in susceptibility to infection between these BALB strains correlated with a difference in the pattern of IL-4 secretion.