Intra-urban air pollution in a rapidly growing Sahelian city.

In this paper we analyze spatial and temporal variations of air pollution (PM(1), PM(2.5), PM(10), CO, NO(x), O(3), Toluene and Benzene) and climate in areas of different development typology in Ouagadougou, Burkina Faso. Analyses are based on measurements from fixed sites and car traverse measurements during field studies in 2007 and 2010. Large spatial and temporal variations were found, showing a generally poor air quality situation, with extreme levels of PM(10), commonly exceeding air quality guidelines of WHO. Pollution levels increase considerably with increased atmospheric stability. Important sources were transported dust and re-suspension of dust from unpaved roads, but also traffic emissions and biomass burning. The spatial variations are examined with focus on effects for variations in potential exposure depending on for example area of residence and daily activity pattern, showing that great differences are likely to exist. Ouagadougou, like most developing countries worldwide, currently experiences an extremely rapid population growth in combination with limited financial means. This is likely to create increasingly harmful air pollution situations for the rapidly growing populations of these areas, and shows an urgent need for increased understanding of the pollution situation as well as development of mitigation strategies.

Asking about condom use: a key to individualized care when screening for chlamydia.

Chlamydia trachomatis (CT) infection has been a target for both selective and national screening programmes, and Sweden has an opportunistic approach. A national plan of action states that risk groups should be identified and offered risk reduction counselling. Patients attending a drop-in sexually transmitted infection (STI) clinic reception at the University Hospital, Umeå, Sweden, were invited to complete a questionnaire regarding sociodemographic characteristics, symptoms and sexual risk behaviour; all had a CT test taken. A total of 1305 patients were included, 58% men, mean age 27.8 years. CT prevalence was 11%; 51% of those with CT were ≥ 25 years old. Only 5% used a condom during the entire sexual intercourse with their last new/temporary partner. Sexually active inconsistent condom users comprised 62% of the study population and contributed to 81% of the chlamydia infections. Asking whether a condom was used could quickly triage patients into groups with a 'higher risk' (none or inconsistent use of condoms and at least one new/temporary partners), and 'lower risk' (with more consistent condom use, although not always accurate) allowing for individualized care and counselling when screening for chlamydia. Evaluating whether a condom was used throughout the sexual intercourse did not add any useful information.

Improved contact tracing for Chlamydia trachomatis with experienced tracers, tracing for one year back in time and interviewing by phone in remote areas.

OBJECTIVES: To evaluate the Swedish model for contact tracing and especially the "Västerbotten model" with centralised, extended contact interview periods, sometimes by telephone. METHODS: Using questionnaires, the contact tracing and interview procedure was evaluated during 2002, followed by an evaluation of contact interviewing by phone in 2005-6. RESULTS: Patients with diagnosed Chlamydia trachomatis infection reported on average 2.5 sexual contacts, 3.0 contacts when contact interviewing was performed at the clinic, and 2.3 contacts when performed by phone. 65% of the sexual contacts with a known test result were infected. CONCLUSION: Centralised contact tracing, exploring the sexual history for at least 12 months back in time, shows good results. Combined with screening of certain risk groups it is probably one effective way of preventing C trachomatis infections. Preventing C trachomatis by primary prevention such as information and counselling is, however, still of great importance.

Demonstration of Chlamydia trachomatis IgG antibodies in the male partner of the infertile couple is correlated with a reduced likelihood of achieving pregnancy.

BACKGROUND: The objective of this study was to determine the prevalence of Chlamydia trachomatis among both men and women seeking help at an infertility clinic, and to prospectively follow the effect of previous infection on pregnancy rates and pregnancy outcome after a long follow-up period (mean 37 months). METHODS: A total of 244 infertile couples was tested for C. trachomatis IgG antibodies, and IgG(+) couples were also tested for C. trachomatis DNA by PCR in a first-void urine sample. Study parameters were serology, PCR results, clinical diagnoses, treatments, pregnancy rates and pregnancy outcome. As controls, age-matched and spontaneously pregnant women were also tested with serology. RESULTS: The prevalence of IgG antibodies was 24.2, 20.1 and 15.6% among infertile women, infertile men and control women respectively. The prevalence of C. trachomatis DNA was 6.8 and 7.1% among tested women and men respectively. The presence of C. trachomatis IgG antibodies in women was related to tubal factor infertility (TFI) (P = 0.002). Decreased pregnancy rates were seen in couples where the man was IgG(+) (P = 0.005) with no relationship to TFI. Among women who achieved pregnancy, there was no difference in pregnancy outcome between IgG(+) or negative couples. CONCLUSIONS: C. trachomatis IgG antibodies in the man of the infertile couple was related to decreased pregnancy rates and to the presence of IgG antibodies in the woman. There was a high prevalence of asymptomatic persistent infections among infertile couples.

Presence of Chlamydia pneumoniae in abdominal aortic aneurysms is not associated with increased activity of matrix metalloproteinases.

OBJECTIVE: to test the hypothesis that the presence of Chlamydia pneumoniae (C. pneumoniae) in the wall of abdominal aortic aneurysms (AAA) is associated with increased activity of matrix metalloproteinase (MMP)-2 and/or MMP-9. DESIGN: case-control study. MATERIAL AND METHODS: in a series of 40 patients with AAA > or =5cm in maximal cross-sectional diameter, C. pneumoniae-DNA was identified in the aneurysm wall by nested PCR in 14 (35%) patients. Another 14 C. pneumoniae-DNA-negative AAA patients from the same series, matched for gender and aneurysm diameter, were used as controls. In each group there were 7 asymptomatic (aAAA) and 7 ruptured (rAAA) aneurysms. MMP-2 and -9 activity was estimated in AAA wall biopsies by gelatin zymography. RESULTS: patients with a C. pneumoniae-DNA-positive aneurysm wall specimen showed an over-all lower activity of MMP-2 and MMP-9 (pro- and active enzyme) compared to the C. pneumoniae-DNA negative patients. However, there were no statistically significant differences in MMP activity between the two groups of patients with aAAA. Among patients with rAAA both pro-MMP-9 (p=0,026) and active-MMP-9 (p=0.007) were significantly lower in C. pneumoniae-DNA-positive patients compared to C. pneumoniae-DNA-negative patients, whereas there were no significant differences in pro-MMP-2 or active-MMP-2. CONCLUSION: this preliminary study does not support the hypothesis that the presence of C. pneumoniae in the AAA wall is associated with increased activity of MMP-2 and MMP-9.

Is Chlamydia pneumoniae found in spinal fluid samples from multiple sclerosis patients? Conflicting results.

Cerebrospinal fluid samples from controls and patients with multiple sclerosis (MS) were split and sent to laboratories with different experiences for the detection of Chlamydia pneumoniae by polymerase chain reaction. Vanderbilt investigators identified C. pneumoniae in the majority of patients with MS and uncommonly in controls. Laboratories at Johns Hopkins University, University of Umeå, and the Centers for Disease Control and Prevention did not identify C. pneumoniae in any of the samples. Conflicting reports of C. pneumoniae detection in the some samples from patents with MS highlight the need to exchange detection techniques among laboratories involved in this controversy.

In vitro degradation of aortic elastin by Chlamydia pneumoniae.

OBJECTIVES: to investigate whether Chlamydia pneumoniae (C. pneumoniae) may increase elastin degradation in the aortic wall. MATERIALS AND METHODS: eighteen full thickness aortic wall samples from non-aneurysmal infrarenal abdominal aortas were collected from autopsies. Two adjacent and equally large pieces were cut out of each aortic sample. From each sample, one piece was incubated in a HEp-2 cell culture infected with C. pneumoniae and the other piece was incubated in an uninfected HEp-2 cell culture. The incubation time was one week at 35 degrees C. The concentration of elastin-derived peptides (EDP) (ng/ml) in the medium of each cell culture was measured in duplicate. For each paired sample, delta-EDP (EDP in HEp-2 cell culture infected with C. pneumoniae- EDP in uninfected HEp-2 cell culture) was calculated. RESULT: there was a significantly increased degradation of aortic elastin, estimated by EDP concentrations in cell culture conditioned medium, when aortic wall samples were incubated in C. pneumoniae cultures compared with uninfected cultures (p=0.025, Wilcoxon signed ranks test). CONCLUSION: these results indicate that there is a relationship between the presence of C. pneumoniae and increased elastin degradation in the aortic wall in vitro. This suggests C. pneumoniae in the aortic wall directly or indirectly leads to the degradation of aortic elastin.

Application of blood-based polymerase chain reaction for detection of Chlamydia pneumoniae in acute respiratory tract infections.

The aim of this study was to investigate whether blood-based polymerase chain reaction could serve as a diagnostic tool to identify individuals with acute respiratory Chlamydia pneumoniae infection. Respiratory specimens and peripheral blood mononuclear cells of 58 patients were analyzed using nested polymerase chain reaction and cell culture. Fifteen patients were polymerase chain reaction-positive for Chlamydia pneumoniae. Nine patients were positive in only the respiratory specimen; two in both the respiratory and blood sample (time intervals between onset of symptoms and sample collection, 3-10 days and 3-4 weeks, respectively); and four in only the blood sample. Detection of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells does not seem to be a suitable marker for acute respiratory Chlamydia pneumoniae infection.

Standardizing Chlamydia pneumoniae assays: recommendations from the Centers for Disease Control and Prevention (USA) and the Laboratory Centre for Disease Control (Canada).

Chlamydia pneumoniae has been associated with atherosclerosis and several other chronic diseases, but reports from different laboratories are highly variable and "gold standards" are lacking, which has led to calls for more standardized approaches to diagnostic testing. Using leading researchers in the field, we reviewed the available approaches to serological testing, culture, DNA amplification, and tissue diagnostics to make specific recommendations. With regard to serological testing, only use of microimmunofluorescence is recommended, standardized definitions for "acute infection" and "past exposure" are proposed, and the use of single immunoglobulin (Ig) G titers for determining acute infection and IgA for determining chronic infection are discouraged. Confirmation of a positive culture result requires propagation of the isolate or confirmation by use of polymerase chain reaction (PCR). Four of 18 PCR assays described in published reports met the proposed validation criteria. More consistent use of control antibodies and tissues and improvement in skill at identifying staining artifacts are necessary to avoid false-positive results of immunohistochemical staining. These standards should be applied in future investigations and periodically modified as indicated.

Failure to demonstrate Chlamydia pneumoniae in cardiovascular tissue from children with Kawasaki disease.

Chlamydia pneumoniae has been associated with atherosclerosis and myocardial infarction in adults. Coronary artery tissues of five fatal cases of Kawasaki disease were examined by PCR; none was positive.

Multicenter comparison trial of DNA extraction methods and PCR assays for detection of Chlamydia pneumoniae in endarterectomy specimens.

The reported rate of detection of Chlamydia pneumoniae DNA within atherosclerotic lesions by PCR varies between 0 and 100%. In this study, identical sets of coded experimental atheroma samples (n = 15) and spiked controls (n = 5) were analyzed by 16 test methods in nine centers by means of PCR. The positive controls were correctly identified to levels of 1, 0.1, and 0.01 inclusion bodies of C. pneumoniae/ml of tissue homogenate by 16 (100%), 11 (69%), and 3 (19%) of the test methods, respectively. Three out of 16 negative controls (19%) were rated positive. Positivity rates for atheroma samples varied between 0 and 60% for the different test methods, with the maximum concordant result for positivity being only 25% for one carotid artery sample. There was no consistent pattern of positive results among the various laboratories, and there was no correlation between the detection rates and the sensitivity of the assay used.

A preliminary evaluation of a new enzyme immunoassay to detect Chlamydia pneumoniae-specific antibodies.

New enzyme immunoassays (EIAs) for determination of specific IgG, IgA, and IgM antibody titers to Chlamydia pneumoniae were evaluated independently in three research laboratories. Specificity of the EIAs was enhanced by removing LPS from the chlamydial antigen. The performance of these EIAs was evaluated in comparison with the microimmunofluorescence (MIF) test using specimens from: (i) a group of adult patients with community-acquired pneumonia (CAP) previously diagnosed as having an acute chlamydial infection by the complement fixation test or the whole inclusion fluorescence test; (ii) from a group of adult patients with acute respiratory tract infections; and (iii) from a group of young children consecutively presenting with acute respiratory tract infections. The MIF test and the EIAs detected acute infections in paired serum specimens from 12 of 14 patients from the first group. Eleven of these 12 patients were positive in both tests. The MIF test detected seven acute infections in single convalescence serum specimens from eight patients. Two of these were also positive in the EIAs. Paired serum specimens from the second group of adult patients (n=12) were collected during an epidemic of C. pneumoniae. The EIAs detected six acute infections. The MIF test detected two additional patients with acute infections. From the group of young children (n=30), the EIAs detected two patients with acute infections. Our conclusion from this preliminary evaluation is that these EIAs could be useful for laboratory diagnosis of acute C. pneumoniae infections. Comprehensive prospective studies should provide suitable data to calculate the sensitivity, specificity, and predictive values.

Is Chlamydia pneumoniae present in brain lesions of patients with multiple sclerosis?

We investigated the presence of Chlamydia pneumoniae in 81 normal and pathological specimens obtained from postmortem brain tissues of patients with multiple sclerosis and with other neurological or nonneurological diseases. The assays used included PCR amplification of all DNA samples in the initial study. Culture and a second PCR amplification of the organism in a subset of 19 brain specimens were also performed in two separate laboratories. All results were negative. Thus, this study on a large number of brain tissues suggests that C. pneumoniae is not involved in inflammatory demyelination.

Small-bowel obstruction secondary to malignant disease: an 11-year audit.

OBJECTIVE: To determine the efficacy and long-term prognosis for operative versus nonoperative treatment of small-bowel obstruction (SBO) secondary to malignant disease. DESIGN: A chart review. SETTING: A university-affiliated teaching hospital. PATIENTS: The medical records of all patients with malignant disease as the established etiology of their obstruction who presented to the Sir Mortimer B. Davis-Jewish General Hospital, Montreal, between 1986 and 1996 were reviewed. There were 32 patients accounting for 74 admissions. INTERVENTIONS: Selective nonoperative management and exploratory laparotomy, immediate or delayed. MAIN OUTCOME MEASURES: The value of nonoperative management and need for operation. RESULTS: Colorectal and ovarian neoplasms were the principal primary malignant diseases that led to SBO. The median time between diagnosis of the malignant disease and SBO was 1.1 years. At their initial presentation, 80% of patients were treated by operation, but 47% of these patients had an initial trial of nonoperative treatment. Reobstruction occurred in 57% of patients who were operated on compared with 72% of patients who were not. The median time to reobstruction was 17 months for patients who underwent operation compared with 2.5 months for patients who did not. Also, 71% of patients were alive and symptom free 30 days after discharge from operative treatment compared with 52% after nonoperative treatment. Postoperative morbidity was 67%. Mortality was 13%, and 94% of patients eventually died from complications of their primary disease. CONCLUSIONS: SBO secondary to malignant disease usually indicates a grim prognosis. Operative treatment has better outcome than nonoperative management in terms of symptom free interval and reobstruction rates. However, it is marked by high postoperative morbidity. We recommend that, after short trial of nasogastric decompression, patients with obstruction secondary to malignant disease be operated on if clinical factors indicate they they will survive the operation.

Etiology of small bowel obstruction.

BACKGROUND: Small bowel obstruction (SBO) is a major cause of morbidity and financial expenditure in hospitals around the world. The leading cause of SBO in the western world has become adhesions. The goal of this study was to determine the causes of SBO. METHODS: The medical records of all patients admitted to one hospital between 1986 and 1996 with the diagnosis of SBO were reviewed retrospectively. This included 552 patients accounting for 1,001 admissions. RESULTS: The etiology of SBO was adhesions (74%), Crohn's disease (7%), neoplasia (5%), hernia (2%), radiation (1%), and miscellaneous (11%). Patients with Crohn's disease were younger than patients with other etiologies. Surprisingly, recurrence rates were similar for patients treated operatively as for those treated nonoperatively with the exception in the hernia group where higher recurrence rates were noted for patients initially treated in a nonoperative manner. CONCLUSION: The most common cause of SBO is adhesions followed by Crohn's disease and neoplasia.

Asthma, skin symptoms, and allergy in a condom factory.

BACKGROUND: Cases of occupational asthma have been reported in condom factories in the UK and France, but there has been no epidemiologic study of groups of workers in such factories. This investigation aimed to study the prevalence of symptoms in a Swedish condom factory, to determine groups at special risk, and to suggest preventive measures. METHODS: A questionnaire was mailed to 35 employees, 29 women and six men with mean ages of 37 and 32 years, respectively. All subjects were interviewed by a physician and underwent skin prick test with latex and epicutaneous testing with 39 substances, and blood samples were taken for allergy testing. RESULTS: Phadiatop was positive in 23%, RAST against Lycopodium in 31%, and RAST against latex in one of these 11. Ten subjects (29%) had work-related nose/eye symptoms; of these, eight had positive RAST to Lycopodium; three also had symptoms of occupational asthma and contact urticaria. Only one had positive RAST to latex. Five of the nine subjects with positive Phadiatop also had positive RAST to Lycopodium. All those with RAST positive to Lycopodium had worked in packaging, the area of the factory with the greatest exposure. The results of the patch tests did not correlate with the work-related symptoms. CONCLUSIONS: In a Swedish condom factory, there were a high prevalence of rhinoconjunctivitis and a small number of cases of asthma and contact urticaria caused by allergy to Lycopodium.