Detection of serum antibodies against measles, mumps and rubella after primary measles, mumps and rubella [MMR] vaccination in children

In Iran, the measles, mumps and rubella vaccine [MMR] is administered in a two-dose protocol where the first dose is scheduled at 12 months of age. This study aims to determine the efficacy of the MMR vaccine by testing IgM and IgG antibody levels 4 - 7 weeks after primary vaccination. A single group cohort study was performed on healthy children, 12 - 15 months of age, who were vaccinated at health centers affiliated with Shahid Beheshti University of Medical Sciences in Tehran, from January to April 2009. Children with negative vaccination and/or clinical history for measles, mumps or rubella were administered the first dose of the MMR live attenuated vaccine. IgG and IgM antibodies were checked by enzyme linked immunoassay [ELISA] in serum samples 4 - 7 weeks after vaccination. A child was considered seropositive if antibody levels were higher than the assay cut-off level set by the ELISA kit. Samples from 240 children were checked for antibodies against measles and rubella. Measles serum IgM level was positive in 71.7% of samples and IgG in 75.8%. The rubella serum IgM level was positive in 71.7% of children and IgG in 73.8%. From 190 blood samples that were checked for mumps antibodies, serum IgM was positive in 68.9% and IgG in 95.3%. No significant relationship was found between seropositivity and age or gender. IgG and IgM antibody levels were below the assay cut-off levels against measles and rubella in approximately one-fourth of the children following primary MMR vaccination. A second dose was necessary to raise the level of protection against measles and rubella

ELISA cut-off point for the diagnosis of human brucellosis; a comparison with serum agglutination test

Brucellosis is a world-wide disease, which has a diverse clinical manifestation, and its diagnosis has to be proven by laboratory data. Serum agglutination test [SAT] is the most-widely used test for diagnosing brucellosis. The enzyme linked immunosorbent assay [ELISA] can also determine specific antibody classes against brucella. It is a sensitive, simple and rapid test, which could be an acceptable alternative to SAT with fewer limitations, however, like any other new test it should be further evaluated and standardized for various populations. This study was planned to determine an optimal cut-off point, for ELISA which would offer maximum sensitivity and specificity for the test when compared to SAT. Four hundred and seven patients with fever and other compatible symptoms of brucellosis were enrolled in the study. Serum agglutination test, 2-Mercaptoethanol test, and ELISA were performed on their sera. The cut-off point of 53 IU/ml of ELISA-IgG yielded the maximal sensitivity and specificity comparing to the other levels of ELISA-IgG, and was considered the best cut offpoint of ELISA-IgG to diagnose acute brucellosis. At this cutoff, the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were 84.09%, 85.38%, 62.20, 94.90, 5.75, 0.18, respectively. The best cut-off point of ELISA-IgG is 53 IU/ml, which yields the maximal sensitivity and specificity to diagnose acute brucellosis

use of polymerase chain reaction assay versus cell culture in detecting neonatal chlamydial conjunctivitis

One of the most common bacterial infections that causes ophthalmia neonatorum is Chlamydia trachomatis, [C. trachomatis]. Very few studies have been performed in Iran using both cell culture and polymerase chain reaction [PCR] methods to determine the prevalence of C. trachomatis as an etiological agent of ophthalmia neonatorum. This study aimed to evaluate the prevalence of neonatal chlamydial conjunctivitis [NCC] as diagnosed by both methods in two hospitals in Tehran, Iran. From March 2008 to May 2009, out of 2253 neonates, 241 [10.7%] with clinical findings of conjunctivitis were included in this study. A total of241 conjunctival swabs were tested by cell culture [as the gold standard test], PCR, and Giemsa staining. Cell cultures were positive for C. trachomatis in 31 [12.9%] neonates, C. trachomatis was positive in 40 [16.6%] neonates by PCR and 18 [7.5%] by Giemsa staining. The sensitivity of PCR was 100%, whereas Giemsa staining sensitivity was 58.1%. High sensitivity [100%] and specificity [95.7%] of PCR as compared to culture makes it a proper diagnostic method for the detection of C. trachomatis

Serologic evidence of pertussis infection in vaccinated Iranian children

It seems that the incidence of pertussis-like illnesses is considerably increasing despite the wide coverage of immunization with the whole cell pertussis vaccine. We aimed to investigate the occurrence of pertussis in vaccinated children by measuring anti-pertussis antibodies. In this cross-sectional study, blood samples were taken from vaccinated children aged 2, 4, 6, 12, 18, and 72 months. Anti-pertussis IgG and IgA were measured by ELISA. P < 0.05 was considered significant. 725 children were enrolled in the study. Geometric mean titers for IgG that showed a slight decease after 2 months of age and increased distinctly in children aged 72 months. The frequency of the individuals whose IgG was above the determined cut-off [derived from mean+2SD] was observed in 1% of the 2, 4, and 6-month-old infants, 6% of the 12 and 18-month-olds and 12% of the 6-year -old children. Positive IgA titers were detected in 5, 9, 6, 23, 11, and 8% of children aged 2, 4, 6, 12, 18, and 72 months, respectively. Since a considerable percentage of children had high levels of anti-pertussis IgG antibodies [>/=2 SD], positive anti-pertussis IgA, and most importantly an increased level of anti-pertussis IgG geometric mean titer at 6 years of age, further investigations regarding the protection provided by the presently used pertussis vaccine seems necessary

Surveillance of ventilator-associated pneumonia in a neonatal intensive care unit: characteristics, risk factors, and outcome

This study determined the incidence, characteristics, risk factors, and outcomes of ventilator-associated pneumonia [VAP] in newborns hospitalized in a Neonatal Intensive Care Unit [NICU] in Tehran, Iran. A prospective cohort study was carried out in the NICU of Mandieh Hospital over a period of one year, from December 2008 to November 2009, on all neonates mechanically ventilated for more than 48 hours. VAP was diagnosed in accordance with the CDC definition of nosocomial pneumonias for patients younger than 12 months. Risk factors relevant to the development of VAP were studied. Multiple logistic and Cox regression analysis were performed to determine independent predictors for VAP and survival rate, respectively. There were 81 neonates enrolled. VAP occurred in 14[17.3%], at rate of 11.6/1000 days on the ventilator. Gram negative bacteria were the predominant etiologic agents. The most common bacterial isolates from the endotracheal aspirate were E.coli [21.4%]. KIebsiella [21.4%], and Pseudomonas [14.1%]. The only VAP predictor was sputum [odds ratio [OR]=5.11, P=0.02]. Mortality rate for VAP was 2/14[14.3%]. Duration of mechanical ventilation [hazard ratio [HR] 0.96, P0.01], birth weight [HR=0.81, P < 0.001], and purulent tracheal aspirate [HR=0.25, P < 0.006] were independent predictors of overall survival. VAP occurs at a significant rate in mechanically ventilated newborns. Additional studies are needed to accurately determine the incidence and risk factors in order to develop effective preventive and therapeutic protocols

Association of serum soluble triggering receptor expressed on myeloid cells levels in malignant febrile neutropenic patients with bacteremia and fungemia

Infections are the major cause of morbidity and mortality in febrile neutropenic patients with malignancy. Rapid diagnostic tests are needed for prompt diagnosis and early treatment which is crucial for optimal management. We assessed the utility of soluble triggering receptor expressed on myeloid cells [sTREM-1] in the diagnosis of bacteremia and fungemia in febrile neutropenic patients. Sixty-five febrile neutropenic children with malignancy hospitalized in Mofid Children's Hospital during a period of one year from January 2007 were recruited for this cross sectional study [mean age 66.2 +/- 37 months; 35 females and 30 males]. Thirty patients [46.2%] had acute lymphoblastic leukemia, 2 [3.1%] acute myeloid leukemia, one [1.5%] lymphoma and 32 [49.2%] were under treatment for solid tumors. Simultaneous blood samples were collected for measurement of serum sTREM-1 levels and for blood cultures which were grown in BACTEC media. Gold standard for the presence of infection was a positive BACTEC culture as a more sensitive method compared to current blood culture techniques. Blood cultures with BACTEC system were positive in 13[20%] patients [12 bacterial and one fungal culture]. The mean serum sTREM-1 level in BACTEC positive patients was 948.2 +/- 592.9 pg/ml but in BACTEC negative cases it was 76.3 +/- 118.8 pg/ml [P<0.001]. The optimal cut-off point of sTREM-1 for detecting patients with positive result of BACTEC was 525 pg/ml with sensitivity and specificity of 84.6% and 100%, respectively. Our study revealed a significant association between serum sTREM-1 level and bacteremia and fungemia in febrile neutropenic patients suffering malignancy with acceptable sensitivity and specificity

Lumbar puncture in neonates under and over 72 hours of age

To identify the criteria for performing a spinal tap in neonates with suspected sepsis and compare the findings in infants under and over the age of 72 hours. Analytical. Neonatal Ward of Taleghani Medical Centre, Shaheed Beheshti University of Medical Sciences, Evin,Tehran. Study period was of one year, from March 2003 to February 2004. All newborns subjected to a lumbar puncture during the first 24 hours of admission were enrolled in the study. Results of cerebrospinal fluid analysis were scrutinized. There were 380 neonates in the study. Majority i.e. 248 infants were aged < 72 hours. Meningitis was diagnosed in 22 cases, [5.8%]. There was no significant difference in the incidence of meningitis between neonates under and over 72 hours of age, [6.9% vs. 3.8%, p-value >0.5]. Comparison of risk factors, clinical manifestations, and routine laboratory investigations revealed no significant difference in babies with or without meningitis. The findings of this series do not support a selective approach for performing a lumbar puncture in a possibly septic newborn. A lumbar puncture is recommended in all neonates with suspected sepsis regardless of age, risk factors, or specific neurological manifestations

Acute glomerulonephritis in children

Acute glomerulonephritis [AGN] remains fairly common in the developing world although its frequency has declined in the industrial countries. The pattern of AGN was studied in one hundred hospitalized children. We recorded an increased prevalence in school age, i.e. 6-15 years [75%] and the occurrence of a streptococcal infection [90%], most often a pharyngeal infection [86%], one to three weeks preceding the illness. The problems that needed specific management during the acute phase were hypertension [39%], encephalopathy [5%] and ARF with hyperkalemia, 2% of the patients needing haemodialysis. Most of our patients [98%] recovered with 2% progressing to RPGN. The excellent prognosis of AGN with proper management emphasises the need for optimal care during the acute phase in the hospitalised children