Serosurvey of Crimean-Congo hemorrhagic fever virus in livestock, Kohgiluyeh and Boyer-Ahmad, Iran, 2017.

BACKGROUND & OBJECTIVES: Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral zoonosis with up to 50% mortality rate in humans. In addition to the role of animals in the transmission of the virus and spread of infected ticks through livestock trade, they can be employed as sentinel hosts for monitoring the infection. Iran is one of the endemic counties for CCHF and the disease has been documented in all provinces. However, in some provinces such as Kohgiluyeh and Boyer-Ahmad, the rate of the disease has been dramatically low. Therefore, this serosurvey was designed to investigate CCHF virus (CCHFV) seroprevalence among livestock in different parts of Kohgiluyeh and Boyer-Ahmad Province. METHODS: This study was conducted in 2017, in which, blood samples were collected from 501 sheep and goats from eight different cities of Kohgiluyeh and Boyer-Ahmad Province. CCHFV IgG antibodies were detected in livestock serum samples by specific ELISA assays for detection of ovine and caprine antibodies. RESULTS: In total, four sheep serum of out of 501 (0.8%) livestock samples (3 from Gachsaran and 1 from Dena) had CCHFV IgG antibodies. No significant association was found between CCHFV seropositivity and sex or age of animals (P>0.05). INTERPRETATION & CONCLUSION: Our findings suggest a minor CCHFV circulation in Kohgiluyeh and Boyer-Ahmad Province, Iran. However, due to the notion that outbreaks of tick-borne infections is hard to predict; steady and comprehensive monitoring programs especially in ticks and animals would be critical for understanding the circulation on the pathogen in a region.

Prevalence and risk factors of intestinal protozoan infections: a population-based study in rural areas of Boyer-Ahmad district, Southwestern Iran.

BACKGROUND: Parasitic infections are still a significant health problem in rural areas in developing countries including Iran. There is no recent population-based data about the prevalence of human intestinal parasites in most rural areas of Iran. The current study aimed to determine the prevalence of intestinal protozoan infection in inhabitants of rural areas of Boyer-Ahmad district, Southwestern Iran. METHODS: A total of 1025 stool samples were collected from the inhabitant of 50 randomly selected villages in Boyer-Ahmad Township. The stool samples were evaluated by parasitological methods including, direct wet-mounting, formalin ethyl acetate concentration, zinc sulfate floatation, and Trichrome permanent stain for detection of protozoan infections. Diarrheic samples were further evaluated with a modified Ziehl-Neelsen staining method for detection of coccidian parasites. RESULTS: The prevalence of both pathogenic and nonpathogenic intestinal parasites in the population was 37.5% (385 out of 1025 cases), some individual with multiple infections. Giardia lamblia was detected in 179 (17.46%), Blastocystis hominis in 182 (17.76%), Entamoeba histolytica/dispar in 9 (0.87%), Endolimax nana in 216 (21.07%), Entamoeba coli in 151 (14.73%), Ioedamoeba butschlii in 45 (4.39%), Chillomastix mesnili in 22 (2.14%), Trichomonas hominis in 2 (0.19%) and Dientamoeba fragillis in 2 (0.19%) of cases. Multivariate logistic regression revealed significant associations between protozoan infection (pathogenic protozoa) and contact with animals (OR yes/no = 2.22, p < 0.001) and educational status (OR higher/illiterate = 0.40, P = 0.01). CONCLUSION: Findings of this study demonstrated that protozoan infection rate in rural areas of southwestern Iran is still high and remained as a challenging health problem in these areas.

Epidemiology of Human Fascioliasis and Intestinal Helminthes in Rural Areas of Boyer-Ahmad Township, Southwest Iran; A Population Based Study.

BACKGROUND: Fascioliasis, caused by Fasciola hepatica and F. gigantica, is one of the most important plant and water borne disease in Iran. This study aimed to determine the prevalence of fascioliasis and intestinal helminthes in inhabitants of rural areas of Boyer-Ahmad in Kohgiluyeh and Boyer-Ahmad province in Southwest of Iran. METHODS: Stool samples (1025) were collected from inhabitant of 50 randomly selected villages in Boyer-Ahmad Township. Samples were evaluated with modified Telemann and formalin-ethyl acetate methods. Blood samples of Fasciola positive cases were assessed with ELISA and Western blotting. DNA was extracted from Fasciola eggs from stool of positive individuals and evaluated by molecular (PCR) method and the PCR products were sequenced and analyzed. RESULTS: Of the 1025 participants, 473 (46.1%) were male and 552 (53.9%) were female. The mean age of the subjects was 20.25 (±15.86) years. Fasciola eggs were detected in stools of two cases (0.19%). Blood samples were obtained from the Fasciola positive cases and their infection was further confirmed by ELISA and Western blotting. Molecular analysis revealed that both cases are infected with F. hepatica. Furthermore, seven of participants (0.68%) were found to be infected with H. nana, 4 cases (0.39%) with E. vermicularis, and one case (0.09%) with Trichuris trichiura. CONCLUSION: Findings of this study showed that Boyer-Ahmad district is one of the endemic areas of human fascioliasis in Iran. The study also documented that the rate of helminthic infections in rural areas of the district has drastically declined over the past years.

The structural and functional studies of His119 and His12 in RNase A via chemical modification.

The histidyl residues of bovine pancreatic ribonuclease A (RNase A) play a crucial role in enzymatic activity. Diethylpyrocarbonate (DEPC) is a potent inhibitor of RNase A, and its precise sites of action on the imidazole rings of the four histidyl residues of RNase A are not clearly defined. We have used a multidisciplinary approach including enzyme assay, calculation of accessible surface area (ASA), isoelectric pH gradient technique, fluorescence investigations, circular dichroism spectroscopy, differential scanning calorimetry, and 1H NMR analysis to study the sites of DEPC interaction with the imidazole rings of the four histidyl residues. Our results demonstrate that among the histidyl residues of RNase A, His48 is not accessible to react with DEPC. However, the sequential carbethoxylation of the imidazole rings of His119, His105, and His12 occurs on the nitrogen atoms of Ndelta, Nepsilon, and Nepsilon, respectively. Carbethoxylation of His119 was followed by conversion of the A conformation to the B conformation in the active site. However, the carbethoxylation of His12 was accompanied by a second spatial rotation of the corresponding imidazole ring in the active site to adopt a new conformation. These conformation changes are accompanied by subsequent decrements in the thermal stability of the protein. Therefore, these findings reinforce the important structural roles of the spatial positions for His119 and His12 in the active site of RNase A.