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

Epidemiology of typhoid fever in Iran during last five decades from 1962-2011

Typhoid fever is one of the most important infectious diseases transmitted by contaminated food and water. This study aimed at epidemiological features of disease during the last five decades, over the period from 1962-2011. A retrospective cross-sectional study was conducted using typhoid fever national surveillance data. The highest incidence of typhoid fever was registered in 1965 with 133.4 /100,000 cases/year and the lowest in 2011 with 0.52/100,000 cases/year. Typhoid fever incidence in Iran had three phases. Before the year 1969, with high incidence >100 [phase 1], the period between1969-1996 with medium [10-100], [Phase 2] and the phase 3 has inaugurated from 1996 until now with low incidence rate less than 10 /100,000. Kermanshah Province was the most infected area. Most cases were occurred in warm months in 2010. Of 196 [31%] cases were under 15 years old whom were more affected. 53.6% of total cases in 2010 were female and 56.6% stayed in rural area. In 2010, 27.8% cases were confirmed. Among positive cases, the sources of culture were 46.8% stool, 37.2% blood, 14.6% urine and 1.2% bone marrow. Following treatment, 97.8% of cases were recovered completely and in 1.6% of cases had experienced complications and only 0.6% of confirmed cases have been died. As a result of development in socio-economic condition in Iran, the typhoid fever incidence has been dramatically declined from high [133.4/100,000 cases/year] in 1965 to low [0.52/100,000 cases/year] in 2011

[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

Epidemiology of nosocomial infections in a pediatric intensive care unit [PICU]

Nosocomial infections [NI] are major concerns in the management of patients in hospitals and are growing problem in developing and developed countries because of increased mortality and morbidity rates and corresponding costs. This cross sectional study was carried out on all patients hospitalized for more than 48 hours in pediatric intensive care unit [PICU] of Rasul Akram hospital in Tehran Nosocomial infection was defined according to the criteria of National Nosocomial Infections Surveillance [NNIS] System. During the study period, 102 patients were hospitalized of whom 15 [14.7%] proved to have NI. The mean duration of PICU stay was 16.1 days for NI group and 8.9 days for non-NI group [p<0.05]. Mortality rate was significantly higher among NI group [40%] when compared with non-NI group [11.5%] [OR=5.13 95% CI:1.29-20.60, p<0.05]. Age under 2 years was a risk factor for NI [OR=4.44, 95% CI:1.23-16.67]. The most common causative organisms for nosocomial infections in PICU were coagulase-negative staphylococci [CONS], followed by Klebsiella and Pseudomonas aeruginosa. Pneumonia was the most common nosocomial infection followed by urinary tract infection and sepsis. The calculated NI rate in our study [14.7%] is higher than usual rates reported from PICU in other societies. Meanwhile, long stay in PICU and age less than 2 years are the main risk factor for NI and subjects with NI are 5.13 times more likely to die

[ effect of age group under 15 years on cholera morbidity during the past 10 years in Iran [1996-2005]]

The study of the effect of age, especially children under 15 years, on cholera morbidity during a period often years [1996-2005] was carried out in Iran. There are no other studies on this topic in Iran and other countries. In this cross sectional study, we used cholera surveillance data collected in Center for Disease Control. All cholera cases were divided into two groups: under 15 years and above 15 years. Incidence rate of cholera per 100000 was calculated in total population and the two mentioned groups during 10 years. The relative risk of less than 15 year-olds group to above 15 year-olds was calculated with95% CI for 10 years by EPI6 and SPSS software. The trend of cholera incidence during the past 10 years shows two epidemic peaks in 1998 and 2005 by the rate of 15.7 and 1.63 per 100000, respectively. During the year with no epidemic and the years between two peaks, the age group under 15 year-olds was more affected with significant relative risk. For example, in 2001 this rate was 4.53. So, we can consider this age group as a risk factor to cholera morbidity. The age group of above 15 year-olds was more affected to cholera during epidemic years [1998, 2005] and relative risk was less than one. So, the age was protective on cholera morbidity for children in these years. One of the most important causes of periodic cholera epidemics every 5-6 years is changing of herd immunity. During the years between two epidemics adults have sufficient immunity and children are more affected because of first exposure and less immunity. With reduced herd immunity epidemics occur. We recommend continuing and strengthening of cholera surveillance system for detection of epidemics and treatment of highly sensitive age groups