Quantiferon-Tb gold and tuberculin skin test for the diagnosis of latent tuberculosis infection in children

Background: Appropriate diagnosis and treatment of latent tuberculosis infection [LTBI] play the most important role in the control of tuberculosis. This study aimed to determine the prevalence of LTBI among healthy tuberculosis unexposed children vaccinated with BCG using the tuberculin skin test [TST] and QuantiFERON TB Gold In-Tube [QFT-GIT] and comparing the agreement between the two tests

Methods: Across-sectional study was carried out between October 2009 and March 2010 in 24 schools and 11 daycare centers. A total of 967 children were divided into 15 age groups, with a minimum of 64 children per group

Results: The prevalence rates of LTBI with TST were 3.8%, and 2.2% with QFT-GIT. One case was positive in TST and QFT-GIT, 20 cases were QFT-GIT positive, but TST negative and 36 cases were TST positive, but QFT-GIT negative, and finally, 910 cases were negative in both. There was poor agreement between TST and QFT-GIT [1.8%, 95%, CI: 0%-5.3%, k-0.007]. The specificity of QFT-GIT in the BCG vaccinated, children aged 1-15 years old, was 97.8% [97.8%, 95% CI: 96.8%-98.8%]. After three months, 2/17[11.8%] of those initially QFT-GIT negative converted, and 10/15 [66%] of those initially QFT-GIT positive reverted

Conclusion: It seems that TST and QFT-GIT are not appropriate tests for the diagnosis of LTBI among healthy tuberculosis unexposed BCG vaccinated children. There was a low reproducibility rate of QFT-GIT. The cause of the the poor agreement requires further studies

Antifungal susceptibility of the Aspergillus species by Etest and CLSI reference methods

Because resistance to antifungal drugs is seen in patients, susceptibility testing of these drugs aids in choosing the appropriate drug and respective epidemiology. This study has investigated and compared susceptibility patterns of the Aspergillus species sisolated from patients by the Clinical and Laboratory Standards Institute [CLSI] reference broth microdilution [MD] assay and Etest method. The minimum inhibitory concentrations [MICs] of various antifungal agents [amphotericin B, ketoconazole, itraconazole, and voriconazole] for 108 Aspergillus species isolated from patients were determined by CLSI M38-A broth MD and Etest. The isolates were obtained from clinical samples that included tissues, sputum, bronchoalveolar lavage, abdominal tap, and cerebrospinal fluid. As revealed by the MD method, 63.9% of the isolates were sensitive to amphotericin B and 36.1% were resistant. Etest revealed that 61.1% were sensitive to amphotericin B and 38.9% were resistant. As for ketoconazole, 108 isolates [100%] were shown to be sensitive through the MD method; while the Etest revealedan 88.9% sensitivity and 11.1% were resistant. All species were susceptible to voriconazole, according to both methods. The measure of agreement [Kappa Index] for these three drugs was satisfactory [>/= 0.6]. According to the MD method, 69.4% of the species were susceptible to itraconazole, whereas 30.6% were not. For this drug, the Etest showed 86.1% susceptible and 13.9% resistant. Voriconazole was the most effective agent against isolates. Using RPMI agar, we found the Etest to be helpful, readily available, and easy to use for determining invitro susceptibilities of Aspergillus species to voriconazole, amphotericin B, ketoconazole, and itraconazole in the region of this study

[Prevalence of latent tuberculosis infection in low-risk children using tuberculin skin test: a study in Shiraz]

Tuberculin skin test [TST] is a readily available test for the diagnosis of latent tuberculosis infection [LTBI]. This study was designed to evaluate LTBI in low-risk children aged 1-15 years. This cross-sectional study was performed in Shiraz, Iran, over six months during 2009. Totally, 1289 boys and girls were selected by stratified multistage random sampling from four municipality areas before allocating them to 15 groups. Inclusion criteria included age 1-15 years, documented history of BCG vaccination at birth, Iranian nationality and a healthy state of being. Children with acute febrile diseases, immunosuppression, on medication and immigrants were excluded. We considered a TST >/= 10 mm of induration as positive. The prevalence of LTBI in 1-15 years old children was 4.5%. The percentage was 3.5% in 1-5 year old, 4.1% in 6-10 year old and 5.7% in 11-15 year old children. The highest rate of infection was 9.8% in 15 year olds and the lowest was 2.2% in 3-year old children. Gender had no effect on LTBI rate. There is no significant difference of LTBI prevalence between four municipality areas. The prevalence of LTBI in this study was lower in comparison with other studies performed in Iran. Positive predictive value of TST decreases in low endemic areas for tuberculosis, especially in low-risk groups; therefore, most positive results are false-positive created by nonspecific reactions and infection with environmental mycobacteria. Hence, there is a need for new diagnostic tools that are easy and cost-effective

Disseminated mycobacterium tuberculosis in an infant with aids

Disseminated Mycobacterium tuberculosis with involvement of liver, spleen, and bone marrow is a nonspecific and rare complication in human immunodeficiency virus [HIV] infected infants. Here, we report a six month old girl with fever, recurrent infections, bilateral axilary lymphadenitis, hepatomegaly, huge splenomegaly, and failure to thrive. The infant and her mother had positive enzyme immunoassay [EIA] and Western blot. HIV DMA PCR test of the infant was positive with subtype A [A1] in genotyping. A positive bone marrow aspirate staining for acid fast bacilli and PCR test on culture revealed Mycobacterium tuberculosis

Assessment of a real-time PCR method to detect human non-cryptococcal fungal meningitis

The signs and symptoms associated with fungal meningitis are similar to those seen with more common bacterial infections. In this study, we investigate whether Aspergillus or Candida DMA can be detected in cerebrospinal fluid [CSF] samples from patients suspected of fungal meningitis using real-time PCR assay. From April 2007 to November 2009, we evaluated CSF samples and sera from patients with risk factors for cerebral fungal meningitis in Nemazi Hospital, Shiraz University of Medical Sciences, Iran, by real-time PCR assay and routine mycological studies [direct microscopy examination and culture]. Two CSF and two serum samples from each patient were examined. CSF and serum samples from 38 patients [total: 152] suspected of fungal meningitis were examined. India ink staining and KOH smear were negative for all patients. C. albicans was isolated from two CSF samples. There were ten patients with positive real-time PCR results in their CSF samples: three patients had C. albicans, one with C. glabrata, four with Aspergillus species and two with both C. albicans and Aspergillus species DMA. Four patients had positive serum results for Aspergillus or Candida infections. Considering the findings, it seems that molecular examination can help in the diagnosis of fungal meningitis in patients with clinical and radiological presentations. Further studies should be conducted in other regions and settings to confirm these findings

Il-1 beta [+3953 C/T] and IL-8 [-251 A/T] gene polymorphisms in H.pylori mediated gastric disorders

Previous studies imply that IL-1 and IL-8 gene variations may play a crucial role in the genetic predisposition to different gastric disorders upon H. pylori infection. The aim of this study was to determine the potential association between the prevalence of certain polymorphic sites and the risk of gastric disorders in Iranian population. One hundred and forty three unrelated individuals with different gastric disorders and 374 normal individuals with no gastric disorders and with a negative serology test for H. pylori [control group] were studied for the association between IL-1 beta [+ 3953 C/T] and IL-8 [-251 A/T] gene polymorphisms and H. pylori - mediated gastritis and gastric ulcer. An analysis of genotype frequency for these genes was performed using RFLP- PCR. Based on the data obtained from culture and pathologic findings, the patients were classified into three subpopulations: H pylori [+] non-ulcerative gastritis [+], H. pylori [+] ulcerative gastritis [+] and H. pylori[-] non-ulcerative gastritis [+]. A significantly higher frequency of TT genotype [p=0.02] in IL-1 beta +3953 in H.pylor[+] ulcerative gastritis [+] was revealed compared to the control group. There were no significant differences among other subpopulations. No significant differences in allele and genotype frequencies of IL-8 [-251A/T] were found among the patients. The data suggest that TT genotype in IL- 1 beta +3953 may be a major contributing genetic risk factor for H. pylori induced gastric ulcer. Moreover, the role of other bacterial and host response factors, such as bacterial adherence peptides, host chemokines, and genes involved in gastric acid secretion, must be further investigated in different ethnic populations

High titers of hemagglutination inhibition antibodies against 2009 H1N1 influenza virus in southern Iran

Pandemic flu had at least two waves in Iran. Knowing how many of the general population were already exposed to this infection has a major impact on national preventive measures. As of December 30, 2009, a total of 3672 confirmed cases of human infection with a novel Influenza A [2009 H1N1] virus had been reported in Iran with 140 deaths. In this study we aim to measure, as a pilot study, the seroprevalence of positive antibody titer [humoral immunity] against 2009 H1N1 virus in Iranian population in Shiraz, Southern Iran. Through cluster random sampling of families residing in Shiraz, 2553 subjects were selected and after a medical interview blood samples were taken and checked for polyclonal antibody against 2009 H1N1 antigen using hemagglutination inhibition assay. An antibody titer of more than 1:40 dilution was considered positive. Data were analyzed considering the demographic characteristics of the population and were compared among different age groups. 1504 [58.91%] samples were tested positive for the presence of polyclonal antibody against 2009 H1N1 virus. The prevalence of positive titers were significantly higher in 60 to 64 years old group and significantly lower in 20 to 24 years old group [p<0.05]. Data did not differ based on other demographic characteristics or the history of flu like illnesses in the past 6 months. High seroprevalence of antibody against 2009 H1N1 in the sera of our subjects describes either a high level of preexisting immunity against H1N1 in Iranian population or a high rate of asymptomatic infection in our area compared to other countries

Expression of recombinant heat-shock protein 70 of MCAN/IR/96/LON-49, a tool for diagnosis and future vaccine research

Heat shock protein 70 [HSP70] is present in all organisms studied so far, and is a major immunogen in infections caused by pathogens including Leishmania spp. The aim of this study was to clone and express HSP70 from L. infantum strain MCAN/IR/96/LON-49 and evaluate antibody response against HSP70 in visceral leishmaniasis [VL]. The L. infantum HSP70 gene segment was amplified by specific primers. It was cloned into pTZ57R vector and subcloned into pET32a [+] expression vector. The new construct was transformed in the E.coli Rosetta strain, and HSP70 protein was expressed in the presence of 1 mM IPTG and purified using a Hi- Trap chelating column. Antibody responses against HSP70 were determined by ELISA in 37 patients with visceral leishmaniasis and 63 healthy controls. Expression of HSP70 protein was confirmed using SDS-PAGE electrophoresis and dot blot with an anti-His tag antibody. There was no difference between the sequence of nucleotides of the HSP70 gene in the present study and other reported sequences. The ELISA results indicated that the sera of 81.1% [30/37] of the patients and 6.3% [5/63] of controls reacted to L. infantum HSP70. The conservative nature of the HSP70 molecule is an advantage in vaccine studies, because of minor differences [6%] between the nucleotide sequences and consequently the similarity in amino acid sequences in various strains of L. infantum. It could therefore be used in vaccine research against leishmaniasis and also as a tool for serodiagnosis

Effect of corticosteroid therapy in esophageal stricture of a child with chronic granulomatous disease

In chronic granulomatous disease [CGD] patients, esophageal stricture is a rare complication and the treatment of choice is still controversial. There are few reports of successful therapy with antibiotics, corticosteroids, multiple balloon dilatations or their combination. We report a 3-three-year-old Iranian boy with recurrent esophageal obstruction due to CGD. The patient transiently responded to dilatation in one occasion and at another time to short term steroid therapy. We observed an excellent response when long term and high dose of corticosteroid was administered. It showed that a long term and high dose steroid therapy is more effective than a short term in a patient with CGD and esophageal stricture

Comparison of arbitrarily primed-polymerase chain reaction and plasmid profiles typing of Pseudomonas aeruginosa strains from burn patients and hospital environment

To identify the strengths and weakness of arbitrary primed-polymerase chain reaction [AP-PCR] and plasmid profiles for typing of Pseudomonas aeruginosa [P. aeruginosa] and tracking of source of infections. Seventy-four strains of P. aeruginosa were isolated from burn patients and hospital environment between January to April 2003 in Ghotbadden Burn Hospital, Shiraz, Iran. The strains were classified by photo Capt Mw program, similarity and clustering of strains were assessed using NTSYS-PC version 2.02K software. Based on 50% and 64.7% and 67.5% similarity on the plotted dendrogram, 38 plasmid profiles were classified into: 2, 3 and 5 clusters, respectively. Photo Capt Mw program categorized AP-PCR products to 47 different types of 6 to 12 bands between 0.376 to 3.7 kb. Based on dendrogram pattern 3 levels [62%, 81% and 84.6%] of similarity were selected. Using these criteria 2, 5and 11 clusters were obtained, respectively. As compared with plasmid profiles, AP-PCR analysis protocol is rapid, reproducible and differentiated the isolates with higher discrimination power. These results suggest that during admission of patients in burn center a limited number of common strains cross-contaminate burn victims. However, transmissions of infection from hospital environment to patients also occur in the minority of the victims. To control cross-contamination of the patient wounds with antibiotics resistant isolates, strong disinfection of patients' bathroom after scrubbing of each patient wounds is mandatory

[Antibiotic susceptibility patterns in H. influenzae type B isolated from healthy children oropharynx in day care centers of Tehran]

Haemophilus influenzae type b [Hib] is a most frequent cause of invasive diseases such as meningitis, septic arthritis and pneumonia in children under 5 years old. Asymptomatic oropharyngeal colonization is an origin of distribution of microorganism to others and probable bacteremia in the same child. The aim of this study was to determine antibiotic susceptibility of Hib in Tehran day care centers. Hib was isolated from oropharynx of 1000 children visiting 25 day care centers selected randomly in different parts of Tehran city during second half of year 2005. For antibiotic susceptibility determination we used disk diffusion test. Ampicillin resistance was 32.3% and Beta lactamase production was seen in 23.6%. Cephalosporins resistance except for cefixime was between 10% to 20% and in cefixime was 58.8%. Rifampin resistance was 17.6%. Resistance to studied macrolids including azythromycin and clarythromycin was 19.6% and 35.3%. On the base of high antibiotic resistance to Hib in our study and other similar studies in Iran, we recommend to use optimal effective and proper antibiotics to decrease the high rate of antibiotics resistance to Hib colonization and its invasive diseases

Immunodominant antigens of helicobacter pylori strains isolated from patients with different gastroduodenal diseases

To detect the immunogenic proteins in Helicobacter pylori [H. pylori] strains isolated from patients with different gastric diseases. We performed this study in the Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran, during July 2003 to September 2004. Total proteins of H. pylori strains isolated from the gastric biopsies of 3 groups of patients were separated by 1D-SDS-PAGE and then blotted with the sera of their respective hosts. In SDS-PAGE the members of each group showed high correlation according to similarity in their patterns, resulting in considering them in the same cluster. The patterns of immunoblots differed from that of Coomassie Brilliant Blue stained gels. The blotting method did not recognize some of the protein bands in the SDS-PAGE. Only the bands of 106 and 45 kDa from H. pylori strains isolated from patients with gastric cancer were significantly [p<0.05] recognized specifically with the sera of their respective patients, and the band of 13 kDa was recognized specifically [p<0.05] with the sera of nonulceric patients. With the exception of these bands, in the patterns of blotting of the sera from all patients no significant differences were observed. By using 1D blotting methods we could find 2 antigenic protein bands [106 and 45 kDa] for H. pylori strains isolated from cancerous patients, and one [13 kDa] for the strains isolated from nonulceric patients, which were specifically recognized with their respective host

Case Report: Churg-Strauss Syndrome in an 8-year-old girl

Churg-Strauss Syndrome [CSS] is a small vessel granulomatous vasculitis that characteristically affects the middle age group and is extremely rare in children. We describe an 8-year-old girl with a prolonged history of cough and eosinophila that initially was labelled as pulmonary tuberculosis, but after complementary assays, associated with skin biopsy, eosinophilic fibrinoid vasculitis, CSS was eventually diagnosed. In this case, due to her young age and more prevalence of infectious lung diseases in our area, there was a few months delay for correct diagnosis and treatment. After meeting the CSS criteria the appropriate treatment was started and her condition improved