Positive Latex Agglutination Test Research Articles

Epidemiology of Streptococcus pneumoniae Serotypes in Jordan Amongst Children Younger than the Age of 5: A National Cross-Sectional Study.

Streptococcus pneumoniae infections are a major cause of mortality and morbidity worldwide. In Jordan, pneumococcal conjugate vaccines (PCVs) are not included in the national vaccination program. Due to the current availability of several PCVs, including PCV-10, PCV-13, and PCV-15, along with PCV-20, currently undergoing pediatric approvals globally, the decision to introduce PCVs and their selection should be based on valid local data on the common serotypes of Streptococcus pneumoniae. This cross-sectional study aimed to identify the frequency of serotypes of Streptococcus pneumoniae in children aged below 5 years hospitalized with invasive pneumococcal diseases (IPDs), including pneumonia, septicemia, and meningitis, during the study's duration in representative areas of Jordan. Serotyping for culture-positive cases was based on the capsular reaction test, known as the Quellung reaction. qPCR was conducted on the blood samples of patients with lobar pneumonia identified via X-ray or on cerebrospinal fluid for those with a positive latex agglutination test for Streptococcus pneumoniae. This study was based on the analysis of the serotypes of 1015 Streptococcus pneumoniae cases among children younger than the age of 5: 1006 cases with pneumonia, 6 cases with meningitis, and 3 cases with septicemia. Only 23 culture-positive cases were identified in comparison to 992 lobar pneumonia cases, which were PCR-positive but culture-negative, with a PCR positivity rate of 92%. Serotypes 6B, 6A, 14, and 19F were the most common serotypes identified in this study, with prevalence rates of 16.45%, 13.60%, 12.12%, and 8.18%, respectively. PCV-10, PCV-13, PCV-15, and PCV-20 coverage rates were 45.32%, 61.87%, 64.14%, and 68.47%, respectively. To the best of our knowledge, this is the largest prospective study from the Middle East and one of the largest studies worldwide showing the serotypes of Streptococcus pneumoniae. It reveals the urgency for the introduction of a PCV vaccination in Jordan, utilizing recently developed vaccines with a broader serotype coverage.

Serological Study of Toxoplasmosis in Slaughtered Animals in Mousl, Iraq

A study was conducted to elucidate the prescence of T.gondii antibodies in the serum of slaughtered cattle, sheep & goats in Mosul abattoir. The study was carried out during the period from October 2002 to March 2003. For serological tests, 300 serum samples were collected from (100) of each slaughtered cattle, sheep & goats. Serum samples collected from slaughtered goats showed the highest percentage of infection using latex agglutination test and was (54%), followed by sheep (49%), while the lowest percentage (23%) was detected in cattle serum. To determine antibodies in positive serum samples, a modified latex agglutination test was used. The highest percentage of IgG was found in sheep (87.8%) followed by cattle (86.96%) and goats (83.3%). However, the highest percentage of IgM was found in goats (16.7%) followed by cattle (13.04%) and sheep (12.2%). A trial for preparing ELISA test manually was conducted in the laboratory of the Microbiology Branch/ College of Veterinary Medicine, University of Mosul, through the isolation of the parasite (antigen) from aborted sheep fetuses. The positive latex agglutination test, were confirmed by ELISA. Of these serum samples, (93.33%) were positive.

Cough, with a sac of marbles in the chest.

A 48-year-old male patient presented with productive cough, dyspnea and abdominal pain of 2 months duration. He was diagnosed with diabetes mellitus 6 months ago and had not been regular with his medications. Clinical examination revealed a respiratory rate of 18 per min with room air saturation of 95%, and a paucity of movements with bronchial breath sounds identified on inspection and auscultation, respectively, over the right hemithorax. Chest skiagram and computed tomography images of his thorax are shown below [Figure 1].Figure 1: (a) shows chest skiagram and (b–d) shows high-resolution computed tomography images of the chest. A description of the images is in the accompanying textQuestion: What is the diagnosis? Answer: Pulmonary and hepatic hydatid disease. DISCUSSION The chest skiagram [Figure 1a] revealed a well-defined round radio-opacity in the right mid zone with a crescentic hyperlucent medial margin, called the crescent sign (white arrow). Figure 1b is a coronal view of high-resolution computed tomography (HRCT) scan of the chest lung window, which shows a large cyst in the right lung, with multiple small rounded opacities with fluid attenuation, some of which appear to be floating within it, appearing like a sac of marbles. This is consistent with a diagnosis of a hydatid cyst with multiple daughter cysts within it. There are pockets of air seen between the outer pericyst and inner endocyst, aptly named ‘air-crescent sign’ (blue arrow) and ‘signet ring sign’ (red arrow), which suggest a ruptured or complicated hydatid cyst. Figure 1c, the sagittal section of the HRCT scan of the chest lung window at the level of the aortic outflow tract, shows the ruptured hydatid cyst in the right lung. The daughter cysts have collected in the dependent area of the larger cyst, with some appearing to ‘rise’ over the rest, or the ‘rising-sun sign’ (blue arrow). Also seen is a small air pocket inferiorly (red arrow) between the pericyst and endocyst, called the ‘air-bubble sign’. The presence of air on either side of the endocyst (red arrowheads) gives the appearance of an ‘onion-peel sign’, or the ‘cumbo sign’. Figure 1d shows a large well-defined homogenous cyst in the right lobe of the liver.[1] Blood investigations revealed uncontrolled blood sugar levels. Armed with the characteristic radiology above, and supplemented by a positive serum latex agglutination test for Echinococcus antigen, he was diagnosed with pulmonary and hepatic hydatid disease. He was started on oral albendazole and subsequently underwent pericystectomy of lung cyst along with partial pericystectomy of cyst in the liver. Post-surgery, he is at present asymptomatic and is on regular follow-up. Hydatid disease is a zoonosis, commonly caused by the accidental ingestion of ova of the tapeworm Echinococcusgranulosus, which subsequently develop into larvae in the host intestine and migrate to other parts of the body where they develop into embryos, with the liver and lung being the most commonly involved organs.[1] Characteristic thoracic radiology should lead clinicians to suspect pulmonary hydatid disease, especially when dealing with patients with non-resolving pneumonia or lung mass. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Alterations in acid-base balance, blood gases, and hematobiochemical profiles of whole-blood and thoracic fluid in goats with contagious caprine pleuropneumonia.

Background and Aim:Contagious caprine pleuropneumonia (CCPP) is a highly contagious and fatal disease affecting goats and some wild ruminants. It is a cause of major economic losses in the goat industry in Africa, Asia, and the Middle East. This study aimed to investigate the acid-base balance, blood gases, and hematobiochemical profiles of whole-blood and fluid collected from the thoracic cavity in goats with CCPP.Materials and Methods:Fifty-five goats suffering from weight loss, anorexia, dyspnea, polypnea, cough, and nasal discharges due to CCPP were studied. Twenty-five healthy goats were used as controls. Diseased animals were enrolled in this study based on a positive serological latex agglutination test (LAT) that confirmed the detection of Mycoplasma capricolum subsp. capripneumoniae. The control goats were enrolled based on a negative result of the LAT.Results:Compared with a mean value of 7.38±0.04 in controls, the pH in the diseased group was 7.41±0.05. The blood pressure of carbon dioxide (PCO2), pressure of oxygen (PO2), base excess (BE), bicarbonate (HCO3), total carbon dioxide (TCO2), and saturation of oxygen (SO2) were lower in goats with CCPP than in controls. However, the anion gap (AnGap) was higher in the diseased goats than in the healthy ones. Compared with the levels in blood samples, the thoracic fluid PCO2, PO2, BE, and SO2 were higher while pH, HCO3, TCO2, and AnGap were lower. Compared with the findings in healthy goats, hematological alterations included significant increases in white blood cells and neutrophils, and a significant decrease in the red blood cell count. In the thoracic fluid, neutrophilic leukocytosis was a remarkable finding. The serum concentrations of globulin, blood urea nitrogen, and glucose, and the activities of aspartate aminotransferase (AST) and g-glutamyl transpeptidase (GGT) increased significantly compared with those in controls. In contrast, serum concentrations of albumin, calcium, and magnesium, and the activity of alkaline phosphatase (ALP) decreased significantly compared with those of healthy animals. The activities of ALP, AST, GGT, and creatine kinase and the concentration of phosphorus were higher in thoracic fluid than the serum values in the diseased group.Conclusion:When compared with the healthy controls, goats with CCPP have metabolic acidosis. Compared with the levels in healthy goats, the blood PCO2, PO2, BE, HCO3, TCO2, and SO2 are low in goats with CCPP; however, the AnGap is higher in diseased goats.

253. Evaluation of a Cryptococcal Antigen Lateral Flow Assay and the Burden of Cryptococcal Disease: A Cohort Study at Grady Memorial Hospital in Atlanta, Georgia

BackgroundWhile Cryptococcus neoformans is a major cause of morbidity and mortality among HIV-infected persons worldwide, there is scarce recent data on disease prevalence in the United States, including in Southeastern states, where HIV rates are high. We sought to determine the prevalence of cryptococcal disease and compare the performance of a cryptococcal antigen (CrAg) lateral flow assay (LFA) vs. latex agglutination (LA) test.MethodsAll patients from Grady Memorial Hospital in Atlanta, Georgia who had a serum or cerebrospinal fluid (CSF) sample sent for CrAg LA testing as part of routine management from November 2017 to July 2018 were included. The LFA was performed on all samples by research staff; results were not available to clinicians. Rates of disease and agreement between the LA test and LFA were calculated.ResultsAmong 467 patients, 570 LA tests were performed; 417 on serum and 153 on CSF (87 patients with multiple tests performed). Mean age was 44 years, and most were male (n = 322, 69%). Most patients had HIV (n = 371, 79%); median CD4 count was 73 cells/mm3 and 77% were not receiving ART. Among HIV-infected individuals, testing was performed equally in the inpatient and outpatient setting. Cryptococcal testing was done in 53 persons without apparent risk factors. Thirty-three (7%) patients had a positive serum or CSF test. Five (1%) patients had both a positive serum and CSF LA test and LFA. While the overall agreement between the LA test and LFA was substantial to high for CSF (κ = 0.71) and serum (κ = 0.93), respectively, there were important discrepancies. Four patients with a negative serum LA test had a positive serum LFA. Five patients had false-positive CSF LA tests, determined by negative CSF LFA testing, India ink, and CSF and fungal cultures. All were treated with amphotericin and flucytosine with one patient experiencing a severe anaphylactic reaction to amphotericin.ConclusionWe found a moderately high rate of cryptococcal disease and important discrepancies between the LA test and LFA. The LFA appeared to be more sensitive for cryptococcemia and more specific for meningitis. Clinical implications of these findings include earlier detection and treatment of cryptococcemia, and averting unnecessary treatment of meningitis with costly medications associated with high rates of adverse events. Disclosures All authors: No reported disclosures.

Identification of Common Bacterial Pathogens Causing Meningitis in Culture-Negative Cerebrospinal Fluid Samples Using Real-Time Polymerase Chain Reaction.

Background. Meningitis is a serious communicable disease with high morbidity and mortality rates. It is an endemic disease in Egypt caused mainly by Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. In some settings, bacterial meningitis is documented depending mainly on positive cerebrospinal fluid (CSF) culture results or CSF positive latex agglutination test, missing the important role of prior antimicrobial intake which can yield negative culture and latex agglutination test results. This study aimed to utilize molecular technology in order to diagnose bacterial meningitis in culture-negative CSF samples. Materials and Methods. Forty culture-negative CSF samples from suspected cases of bacterial meningitis were examined by real-time polymerase chain reaction (real-time PCR) for the presence of lytA, bexA, and ctrA genes specific for Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, respectively. Results. Positive real-time PCR results for Streptococcus pneumoniae were detected in 36 (90%) of culture-negative CSF samples while no positive results for Haemophilus influenzae or Neisseria meningitidis were detected. Four (10%) samples were negative by real-time PCR for all tested organisms. Conclusion. The use of molecular techniques as real-time PCR can provide a valuable addition to the proportion of diagnosed cases of bacterial meningitis especially in settings with high rates of culture-negative results.

Profile and mortality outcome of patients admitted with cryptococcal meningitis to an urban district hospital in KwaZulu-Natal, South Africa.

IntroductionCryptococcal meningitis (CCM) is one of the leading causes of early mortality among HIV-infected patients. This study was a part of clinical audit [1] aimed at improving care for patients with CCM at an urban district hospital in South Africa.MethodsClinical records of all patients (age>13 years) admitted to the hospital with a diagnosis of CCM (based on a positive India ink, positive cryptococcal latex agglutination test (CLAT) or a positive culture of Cryptococcus neoformans) between June 2011 and December 2012 were retrospectively reviewed. Descriptive statistics and Chi-square analysis were generated with Epi Info 7.1.2.0. 95% confidence intervals were reported where appropriate.ResultsOf the 127 patients admitted with CCM, only 97 (76.4%) knew their HIV status. Only 44.8% (43/96) of those who knew they were HIV positive were on antiretroviral therapy (ART). Seventeen out of 25 patients (68%) previously treated for CCM had defaulted fluconazole and only 60% (15/25) were on ART. Acute mortality (death within 14 days of CCM diagnosis) was 55.9% (71/127). The median time to death from diagnosis was four days (IQR 2–9). The association between CSF WBC count<20cells/mL and increased risk of death within 14 days was statistically significant (OR 2.2; 95% CI 1.1–4.6, p=0.03). Patients with heavy cryptococcal burden (reported as numerous yeasts seen on microscopy) at diagnosis were three times more likely to die within 14 days of diagnosis of CCM (OR 3.2; 95% CI 0.9–10.7, p=0.06). Even though a CD4 count<100cells/mm3 was associated with a 1.6 times increased acute mortality risk, the association was not statistically significant (OR 1.6; 95% CI 0.6–4.6, p=0.3). The role of elevated CSF opening pressure at diagnosis was not assessed because only two (1.6%) patients had their baseline opening pressure measured.ConclusionsAcute CCM-related mortality remains high. The number of patients who do not know their HIV status, the number of HIV positive patients not on ART, the high level of non-adherence to fluconazole and the proportion of patients not on ART after at least one previous CCM episode all point to the need of developing comprehensive strategies aimed at encouraging HIV testing and improving patient's retention in HIV care and support.

Epidemiology of invasive meningococcal disease in the Netherlands, 1960–2012: an analysis of national surveillance data

Epidemiological data for invasive meningococcal disease is essential for public health policy and vaccine development. We analysed national surveillance data from the Netherlands for PorA coverage of two PorA-based meningococcal serogroup B vaccines to describe the epidemiology of invasive meningococcal disease. We examined national surveillance data from the Netherlands Reference Laboratory of Bacterial Meningitis (NRLBM) for cases of culture-positive invasive meningococcal disease from Jan 1, 1960, to Jan 1, 2013. We included cases with a meningococcal isolate cultured from cerebrospinal fluid, blood, skin biopsy, or all, and cases with a positive cerebrospinal fluid latex agglutination test, counter current electrophoresis test, or positive cerebrospinal fluid PCR for Neisseria meningitidis. To test for completeness of case ascertainment, we compared data of the NRLBM with those of the Dutch National institute for public health and the environment (RIVM) to which notification was compulsory. We did serogrouping by ouchterlony gel diffusion. We tested susceptibility of meningococcal strains by agar dilution and E test. We tested differences between proportions with the Pearson χ(2) test or Fisher's exact test, and differences in frequencies between time periods with the Mann-Whitney U test. We defined penicillin resistance as MIC of 1·0 μg/mL or higher. Annual incidence rates of invasive meningococcal disease per 100 000 population increased from 0·5 in 1960, to 4·5 in 2001, and subsequently decreased to 0·6 in 2012. Median age increased from 1·8 years in 1960, to 6·1 years in 2012 for all serogroups. The proportion of blood culture positive cases increased from 4% in 1960, to 60% in 2012 (p<0·0001). Serogroup B was the most common serogroup over time, 64% of isolates were from ST-41/44 complex. We established PorA finetype of 4133 isolates, 19 of 252 variable regions covered 99% of sequenced serogroup B cases. Coverage of the 4CMenB PorA component was 4% in 1960-65, and 36% in 2006-12. In response to a serogroup C epidemic (1999-2001), serogroup C conjugate vaccine was introduced, which reduced serogroup C disease by 95%. Since 2003, serogroup Y disease emerged and serogroup A disease disappeared. We identified evidence of capsular switching, but not of serogroup replacement. The rate of reduced penicillin susceptibility increased to 37% from 1993 to 2012, but penicillin resistance was not recorded. Incidence of invasive meningococcal disease has decreased, but decreasing rates of penicillin susceptibility and the possible resurgence of this devastating disease remain a threat to public health. Our long-term serosubtyping and porA sequencing data is valuable for the assessment of vaccine coverage and future serogroup B vaccine development. National Institute of Public Health and the Environment, the European Union's seventh Framework programme, Netherlands Organization for Health Research and Development, Academic Medical Center, and the European Research Council.

Group B Streptococcal Meningitis in Infants Beyond the Neonatal Period

To describe the clinico-bacteriological profile, and early outcomes of infants diagnosed with Group B streptococcus (GBS) meningitis. This was a retrospective review of infants (aged 1mo to 2y) diagnosed with GBS meningitis in a tertiary care hospital in New Delhi from October 2010 through January 2012. The clinico-bacteriological data and early outcomes of infants with suspected bacterial meningitis and a positive CSF latex agglutination test for GBS were studied. The CSF samples were subjected to PCR for broad spectrum 16s ribosomal DNA and the GBS species specific gene, the scpB. Twenty seven patients (13 boys, and 14 girls) were diagnosed with GBS meningitis during the study period. Broad spectrum 16s ribosomal DNA PCR was performed on 18 of the 27 CSF samples. Sixteen were positive. All these 16 were also positive for the species specific scpB gene. The median duration of hospital stay was 7d (range 1-72d). Nine patients died. One patient each developed ventriculitis, optic atrophy and hydrocephalus. Overall, 12 patients had a complete recovery at discharge. GBS must be considered in the etiology of bacterial meningitis in Indian infants.

COMMUNITY‐ACQUIRED BACTERIAL MENINGITIS IN OLDER PEOPLE

To the Editor: A definition such as the one used in the study “Community acquired bacterial meningitis in older people”1 that makes culture positivity of cerebrospinal fluid (CSF) an absolute requirement for the diagnosis of bacterial meningitis might be too restrictive, thereby increasing the likelihood of underrecognition or even misdiagnosis of this disorder. An acknowledgment that meningitis could be characterized by coexistence of bacteremia and culture-negative CSF is implicit in diagnostic criteria that specify “presence of clinical symptoms and signs of meningitis and identification of pneumococci in the CSF by culture, Gram stain, or antigen detection using latex particle agglutination and/or growth of pneumococci from blood cultures.”2 In that study, seven of 87 patients with clinical stigmata of meningitis had bacteremia coexisting with CSF that was sterile on culture but nevertheless exhibited features such as positive Gram staining for diplococci or a positive latex agglutination test for Streptococcus pneumoniae.2 In another report, a patient who presented with some of the clinical stigmata of meningitis and had a positive blood culture for Streptococcus pneumoniae that coexisted with initially sterile CSF, the latter being also acellular, exemplified discordance between blood and CSF culture. It was only on repeat lumbar puncture that a culture-positive CSF was obtained, which now also had profuse pleocytosis typical of bacterial meningitis.3 In the context of pneumococcal meningitis, bacteremia is age related and also appears to be associated with CSF cellularity of less than 1,000 per μL.4 A CSF cellularity of less than 1,000 per μL, in turn, overlaps with the cellularity found in tuberculous meningitis,5 thereby increasing the risk of diagnostic confusion between the two disorders, especially when the latter is characterized by a predominance of neutrophils in its cell content.5 The risk of diagnostic confusion is potentially greatest when the CSF is sterile, a risk that a 100% blood culture rate and prompt acquisition of results can mitigate. The latter is an achievable aim, given the fact that, in bacteremic patients with pneumococcal meningitis, positive blood culture results can be obtained within 1.2 to 10.9 hours of being ordered.6 This could sometimes be well within the time it takes to order a lumbar puncture, which is potentially subject to delays such as the perceived requirement to perform a preliminary computed tomography scan.7 The diagnostic advantage conferred by prompt acquisition of positive blood culture results would be even more decisive in cases in which the initial CSF is sterile and has low cellularity, the latter exemplified by CSF cell counts as low as 3 per μL2 or even total acellularity.3 In conclusion, clinicians need to be alert to the existence of a subgroup of patients with bacterial meningitis in whom clinical stigmata and bacteremia coexist with culture-negative cerebrospinal fluids. A 100% blood culture rate and early acquisition of positive blood culture results could have a decisive effect on the management and prognosis of such patients. Financial Disclosures: I have no conflicts of interest. I have no financial disclosure to make. Author Contributions: I take full responsibility for the concept and design of this document, analysis and interpretation of data, and preparation of the manuscript. Sponsor's Role: There is no sponsor.

Population-based surveillance for cryptococcosis in an antiretroviral-naive South African province with a high HIV seroprevalence

To measure the burden of disease and describe the epidemiology of cryptococcosis in Gauteng Province, South Africa. The study was an active, prospective, laboratory-based, population-based surveillance. An incident case of cryptococcosis was defined as the first isolation by culture of any Cryptococcus species from any clinical specimen, a positive India ink cryptococcal latex agglutination test or a positive histopathology specimen from a Gauteng resident. Cases were identified prospectively at all laboratories in Gauteng. Case report forms were completed using medical record review and patient interview where possible. Between 1 March 2002 and 29 February 2004, 2753 incident cases were identified. The overall incidence rate was 15.6/100 000. Among HIV-infected persons, the rate was 95/100 000, and among persons living with AIDS 14/1000. Males and children under 15 years accounted for 49 and 0.9% of cases, respectively. The median age was 34 years (range, 1 month-74 years). Almost all cases (97%) presented with meningitis. Antifungal therapy was given to 2460 (89%) cases of which 72% received fluconazole only. In-hospital mortality was 27% (749 cases). Recurrences occurred in 263 (9.5%) incident cases. Factors associated with death included altered mental status, coma or wasting; factors associated with survival included employment in the mining industry, visual changes or headache on presentation. This study demonstrates the high disease burden due to cryptococcosis in an antiretroviral-naive South African population and emphasizes the need to improve early recognition, diagnosis and treatment of the condition.

Is measurement of IgM and IgA rheumatoid factors (RF) in juvenile rheumatoid arthritis clinically useful?

The prevalence and clinical relevance of IgM and IgA RF detected by ELISA were studied in 91 patients with juvenile rheumatoid arthritis (JRA) and 45 healthy children. IgM and IgA RF were detected, respectively, in 33 and 44% of the patients, compared to 6.7 and 15.6% of the healthy children (p = 0.001 and 0.0006, respectively). The frequency of IgM RF was significantly higher in patients with polyarticular (52%) as compared to systemic onset JRA (21%; p = 0.04). Five out of ninety-one patients and none of the control group were IgM RF positive by the latex test. High levels of IgM RF were detected more frequently in patients with active disease (p = 0.01) and positive latex agglutination test (p < 0.001) and had a marginally significant association with severe radiological deformities (p = 0.05). The presence of IgA RF was associated with active disease in polyarticular onset JRA children (p = 0.04). In conclusion, high levels of IgM RF and the detection of IgA RF can be useful in assessing clinical activity in a subset of patients with JRA.

A nested PCR assay to detect DNA in sera for the diagnosis of deep-seated trichosporonosis.

Deep-seated trichosporonosis caused by Trichosporon asahii has a high mortality rate and a very poor prognosis. New species-specific oligonucleotide primers for T. asahii were developed from a sequence analysis of rRNA genes that included the internal transcribed spacer regions. A nested PCR assay with specific primers was used to examine 11 serum samples from 7 patients, who were diagnosed with deep-seated trichosporonosis histologically at autopsy. In addition, Trichosporon cell wall polysaccharide (PS) was detected by a latex agglutination (LA) test. Of 11 samples, seven had a positive LA test, and T. asahii DNA was also detected with the nested PCR assay. Of the four samples in which PS antigen was not detected, the nested PCR of two samples was positive. Our new nested PCR assay may be used as an adjunct to conventional methods for diagnosing T. asahii infection.

Epidemiologic study of bacterial meningitis in Jakarta and Tangerang: preliminary report.

To identify the cause of bacterial meningitis in children >1 month of age and <5 years of age in several hospitals in Jakarta and Tangerang, Indonesia. Hospital-based, prospective surveillance study of 100 subjects between 1 month and 5 years of age. Subjects meeting inclusion criteria were evaluated for clinical and laboratory findings of bacterial meningitis. Of 16 subjects enrolled thus far, 11 have been diagnosed as bacterial meningitis. Of these 11, 6 had positive cerebrospinal fluid (CSF) cultures (2 with Haemophilus influenzae and one each with Neisseria meningitidis, Staphylococcus aureus, Klebsiella ozaenae and Escherichia coli). Three of the 6 had positive latex agglutination tests (LAT; 2 H. influenzae and 1 N. meningitidis); LAT was negative for all 10 with negative CSF culture. CSF Gram-stained smear was positive only for the subject with E. coli. The number of children admitted with bacterial meningitis has been declining, perhaps because of early treatment with antibiotics in the community. Of culture-positive cases 33% have been caused by H. influenzae, but this result is based on few patients thus far. LAT has correlated well with culture, whereas Gram stain has had low sensitivity, perhaps reflecting deficiencies in technique.

Management of the young febrile child: a commentary on recent practice guidelines.

Recently published “practice guidelines”1,2 and randomized antibiotic trials3,4 reflect a climate of increased diagnostic testing, more frequent treatment, and more invasive (ie, parenteral rather than oral) treatment of febrile children 3 to 36 months of age. For children in this age group with a temperature ≥39.0°C, the guidelines1,2 suggest a white blood cell (WBC) count and provide two options with respect to obtaining a blood culture: all such children or those whose WBC count is ≥15 000/mm2. Culture of urine obtained by catheterization or suprapubic aspiration is recommended for all boys <6 months and all girls <24 months. The guidelines recommend empiric treatment with ceftriaxone, once again with two options: treat all such children or those whose WBC count is ≥15 000/mm2. These practice guidelines are based on a meta-analysis that pooled data from both randomized controlled trials and observational (nonexperimental) studies of clinical outcomes in young febrile children, and on the views of an expert panel chosen by the senior author.1,2 Although the guidelines have not been officially endorsed by any professional organization, they were developed by authors who are widely recognized in the field and thus could have an important impact on both clinical practice and health care policy. The clinical setting is that of a child with acute onset (≤4 days) of fever who does not appear “toxic” (ie, seriously ill) and has no apparent focus of bacterial infection (otitis media, pneumonia, osteomyelitis/septic arthritis, lymphadenitis, cellulitis, dysentery-like enteritis, or meningitis) after a history is obtained and a physical examination is performed. When confronted with such a child, the clinician must make a series of decisions: 1. Should she obtain diagnostic tests to identify an “occult” bacterial infection [such as pneumonia, bacteremia, meningitis, or urinary …

Evaluation of suprapubic bladder aspiration for detection of group B streptococcal antigen by latex agglutination in neonatal urine.

Our objective was to determine whether urine collection by suprapubic bladder aspiration (SBA) improves the specificity of the group B streptococcal (GBS) latex agglutination (LA) test by avoiding contamination of urine with GBS from perineal and rectal colonization that can result in a positive LA test in an uninfected infant when the urine is collected by bag. Part 1 consists of a retrospective review of the medical records of 113 infants who had urine collected by SBA for GBS LA testing as part of evaluation for possible sepsis. The sensitivity and specificity of the urine LA test was assessed by comparing it with blood culture results. In part 2, a prospective analysis was performed of 19 newborns who had rectal and vaginal/penile cultures as well as urine by SBA and bag for GBS cultures and LA. Results of LA testing on urine collected by both of these methods were compared with results of urine, perineal, and rectal cultures. In the retrospective review of GBS LA testing performed on 113 consecutive urine specimens collected by SBA from neonates being evaluated for suspected sepsis, the sensitivity and specificity were 67% and 89%, respectively, when compared with blood culture results. Twelve infants who had a positive LA test result but a sterile blood culture (BC-,LA+) were compared with 95 infants with both blood cultures and urine LA tests negative for GBS (BC-, LA-). BC-, LA+ infants were more likely than those with BC-, LA- to have an immature to total neutrophil (I/T) ratio > or = 0.16 at 12 and 24 hours (p = 0.04 and 0.02, respectively). In the prospective study, we found that a positive GBS LA test can be due to perineal contamination and possibly to gastrointestinal absorption of GBS antigen. No false positive LA test results occurred on urine obtained by SBA; however, use of this method failed to detect the one infant with GBS bacteremia. Because of suboptimal sensitivity and specificity, use of the GBS LA test on urine obtained either by SBA or bag cannot be recommended for diagnosis of early onset GBS disease.

Helicobacter Pylori Antibodies in a Saudi Population

The authors determined the sensitivity and specificity of a rapid latex-agglutination test (Pylori-set) to detect Helicobacter pylori infection and screened an asymptomatic Saudi population in different age groups for H. pylori seroprevalence. The study was designed as a blind comparison of a commercial serologic test kit for serologic diagnosis of H. pylori with a standard biopsy-related test in a tertiary referral center and teaching hospital. We included 70 symptomatic male and female Saudi patients, as well as 90 randomly collected sera from asymptomatic Saudi patients. The sensitivity of the Pylori-set was 59%, with a specificity of 89%. Screening of the asymptomatic Saudi population showed an age increase in antibody prevalence. Because of the limited sensitivity in the investigated population, the use of this latex-agglutination test alone cannot be recommended for the serological diagnosis of H. pylori infection in the Saudi population.

Use of the Pastorex aspergillus antigen latex agglutination test for the diagnosis of invasive aspergillosis.

To evaluate the Pastorex aspergillus antigen latex agglutination test for the diagnosis of invasive aspergillosis in patients undergoing liver or bone marrow transplantation. Serum samples were taken at least twice weekly post-transplant and tested for Aspergillus antigen. Latex agglutination test results were compared with microbiological examination of respiratory, urine and bile specimens. Serum samples from liver transplant patients were also tested for antibodies to Aspergillus fumigatus by counter immunoelectrophoresis. Eight of the 91 patients studied developed invasive aspergillosis. Positive latex agglutination tests were obtained in eight of 187 (4.3%) serum samples from four of these eight patients. The other four patients with invasive aspergillosis gave consistently negative latex agglutination tests. A positive latex agglutination test was the first indication of invasive aspergillosis in two patients; these patients were already on amphotericin B. Positive latex agglutination tests were the only evidence of invasive aspergillosis in one patient who subsequently died of the infection. False positive latex agglutination tests were obtained in five of 83 (6%) patients with no evidence of invasive aspergillosis and misleading positive cultures seen in nine of 83 (10.8%). No antibodies were detected in three of four liver transplant patients with invasive aspergillosis. Conversely, antibodies were detected in 63 of 262 (24%) serum samples from 43 liver transplant patients with no evidence of invasive aspergillosis; one of these patients had an antibody titre of 1:2 on four separate occasions. The Pastorex aspergillus antigen latex agglutination test, when used alone, lacks sensitivity and specificity for the early diagnosis of invasive aspergillosis. A diagnosis was made in all patients with invasive aspergillosis when both culture and antigen tests were performed although using these criteria a false positive diagnosis would have been made in 13 of 83 (15.6%) patients. Microbiological and serial serological investigations for antigen should both be performed and the results considered in conjunction with radiological and clinical evidence.

Identification of Sepsis in Neonates Following Maternal Antibiotic Therapy

To examine the value of current diagnostic tests identifying neonatal sepsis related to intrapartum treatment with antibiotics, we reviewed the charts of 219 mother-infant pairs, of which 139 mothers received intrapartum antibiotics (group 1) and 80 mothers did not (group 2). When compared with group 2 infants, group 1 infants had fewer positive blood cultures (4.3% vs 20%, P < 0.003), blood cultures positive for group B streptococci (GBS) (P < 0.001), and positive urine GBS latex agglutination (LA) tests (P < 0.001). Although the sensitivity of the white blood cell count (WBC) was 81%, the specificity was < 60% in both groups. The specificity of the urine GBS LA test was 92%. These results suggest (1) the WBC will neither confirm nor rule out neonatal septicemia; (2) blood cultures are indicated in suspected neonatal sepsis even if there was maternal intrapartum treatment with antibiotics; and (3) a urine GBS LA test is a useful adjunct in the diagnosis of neonatal GBS septicemia.

Estimation of the prevalence of cryptococcal infection among patients infected with the human immunodeficiency virus in New York City.

Cryptococcal infections are not reportable illnesses, and there have been limited attempts to estimate their incidence or prevalence. This study estimates the prevalence of cryptococcal disease in New York City in 1991 among human immunodeficiency virus (HIV)-infected patients who were at risk. Numerator data were generated by surveying all hospitals in New York City to determine the number of patients with cultures positive for Cryptococcus neoformans as well as the number of patients with positive cryptococcal latex agglutination tests in 1991; 517 culture-positive patients were identified, and 1,277 patients were estimated to have a positive cryptococcal latex antigen test. Of these cases, 96% were estimated to be related to infection with HIV. Denominator data were generated via an active surveillance program of the New York City Department of Health. The annual prevalence of cryptococcosis among HIV-infected patients at risk in New York City is estimated to be 6.1%-8.5%.