Malaria case investigation with reactive focal testing and treatment: operational feasibility and lessons learned from low and moderate transmission areas in Amhara Region, Ethiopia.

BACKGROUND: When malaria transmission is very low, investigation of passively detected malaria cases and reactive focal testing and treatment (FTAT) in the case and neighbouring households can identify and contain the source and spread of infections. METHODS: Case investigation with reactive FTAT for malaria was implemented in 10 villages in Amhara Region, Ethiopia during the 2014/2015 malaria transmission season. Intervention villages were purposively selected based on the incidence of passively detected Plasmodium falciparum and mixed infections (P. falciparum and Plasmodium vivax) during the 2013 transmission season. A passively detected P. falciparum or mixed index case triggered an investigation that targeted the index case household and the closest 10 neighbouring households in a 100-m radius. All consenting household members received a rapid diagnostic test (RDT) and RDT-positive individuals received artemether-lumefantrine (P. falciparum, mixed) or chloroquine (P. vivax). RESULTS: From October 2014 to February 2015, 407 P. falciparum or mixed index cases (approximately 6.5 per 1000 population) were passively detected. Of these, 220 (54.1%) were investigated, of which 87.3% were male, 61.8% were age 20-39 years [median age: 27 years (range 1-90)], and 58.6% spent ≥ 1 night away from home in the past month (ranging from 0.0 to 94.1% by village). Among the 4077 residents in the 914 households investigated, 3243 (79.5%) received an RDT and 127 (3.9%) were RDT-positive (2.2% P. falciparum, 0.5% P. vivax, 1.2% mixed). Three epidemiological patterns were found. In six villages, there were almost no cases, with less than 10 index and secondary cases. In three villages, most index cases had a history of travel (> 62%), but there were a small number of secondary cases (< 10). Lastly, in one village none of the index cases had a history of recent travel and there was a large number of secondary cases (n = 105). CONCLUSIONS: Three types of malaria transmission patterns were observed: (1) low importation and low local transmission; (2) high importation and low local transmission; and, (3) low importation and high local transmission. To achieve malaria elimination in Amhara Region, intervention strategies targeting these different patterns of transmission and population movement are required.

Mass testing and treatment for malaria in low transmission areas in Amhara Region, Ethiopia.

BACKGROUND: In areas with ongoing malaria transmission, strategies to clear parasites from populations can reduce infection and transmission. The objective of this paper was to describe a malaria mass testing and treatment (MTAT) intervention implemented in six kebeles (villages) in Amhara Region, Ethiopia, at the beginning of the 2014 transmission season. METHODS: Intervention kebeles were selected based on incidence of passively detected Plasmodium falciparum and mixed (P. falciparum and P. vivax) malaria cases during the 2013 malaria transmission season. All households in intervention kebeles were targeted; consenting residents received a rapid diagnostic test (RDT) and RDT-positive individuals received artemether-lumefantrine for P. falciparum/mixed infections or chloroquine for P. vivax. Data were collected on MTAT participation, sociodemographic characteristics, malaria risk factors, and RDT positivity. RESULTS: Of 9162 households targeted, 7974 (87.0 %) participated in the MTAT. Among the 35,389 residents of these households, 30,712 (86.8 %) received an RDT. RDT-positivity was 1.4 % (0.3 % P. vivax, 0.7 % P. falciparum, 0.3 % mixed), ranging from 0.3 to 5.1 % by kebele; 39.4 % of RDT-positive individuals were febrile, 28.5 % resided in the same household with another RDT-positive individual, 23.0 % were not protected by vector control interventions [mosquito net or indoor residual spray (IRS)], and 7.1 % had travel history. For individuals under 10 years of age, the odds of being RDT-positive was significantly higher for those with fever, recent use of anti-malarial drugs or residing in the same household with another RDT-positive individual; 59.0 % of RDT-positive individuals had at least one of these risk factors. For individuals 10 years of age and older, the odds of being RDT positive was significantly higher for those with reported travel, fever, recent use of anti-malarial drugs, no use of vector control, and those residing in the same household as another RDT-positive individual; 71.2 % of RDT-positive individuals had at least one of these risk factors. CONCLUSIONS: In the Ethiopia setting, an MTAT intervention is operationally feasible and can be conducted with high coverage. RDT-positivity is low and varies widely by kebele. While several risk factors are significantly associated with RDT-positivity, there are still many RDT-positive individuals who do not have any of these risk factors. Strategies that target populations for testing and treatment based on these risk factors alone are likely to leave many infections undetected.

Binding of different forms of lipopolysaccharide and gene expression in bovine blood neutrophils.

The objective of this study was to evaluate the effect of smooth (S) and rough (R) forms of lipopolysaccharide (LPS) on gene expression in bovine blood neutrophils. Isolated neutrophils (10(7) cells/mL) were treated with Escherichia coli LPS serotype O111:B4 (S+R) and R forms (Ra, Rd, or Rc). Flow cytometry was used to assess surface expression of toll-like receptor 4 (TLR-4). Specific primers for IL-8, tumor necrosis factor-alpha (TNF-alpha), IL-1beta, cluster of differentiation antigen 14 (CD14), and natural resistance associated macrophage protein 1 (Nramp1) were used to assess transcription. Secretion of IL-8, TNF-alpha, or IL-1beta was determined using ELISA kits. Both S and R forms of LPS bound to neutrophils. Exposure induced increased surface expression of TLR-4. No TLR-4 or CD14 mRNA was detected but transcripts for IL-8, TNF-alpha, IL-1beta, and Nramp1 were detected. Secretion of IL-8 and TNF-alpha but not IL-1beta was observed following treatment with R forms of LPS. The longest R form tested (Ra) increased RNA purity and IL-8 and TNF-alpha secretion in bovine neutrophils. The Rd form increased TLR-4 expression and reduced IL-8 and TNF-alpha secretion. Exposure to LPS induced increased cell surface expression of TLR-4 and enhanced expression of IL-8 genes. Enhanced TLR-4 activity by LPS was not dependent on transcriptional activation. Recruitment of TLR-4 to the cell membrane may account for increased cell surface expression. A CD14-independent, TLR-4-dependent pathway may be important in the response to different forms of LPS by bovine neutrophils.

Effects of ranitidine bismuth citrate on Helicobacter pylori motility, morphology and survival.

AIM: The effects of the anti-ulcer agents ranitidine bismuth citrate (RBC), ranitidine hydrochloride (R) and colloidal bismuth citrate (BC), on Helicobacter pylori motility, morphology and survival were examined to determine whether the clinical effectiveness of RBC might be linked to a specific action that inhibits bacterial motility. METHODS: H. pylori from patients with duodenal ulcer or non-ulcer dyspepsia were exposed to RBC and BC at bismuth concentrations ranging from 12.5 to 50 microg/mL, and R at ranitidine concentrations ranging from 12.5 to 50 microg/mL for a brief period (< 15 min), 6 h and 24 h. Bacterial motility was assessed with a Hobson BacTracker, bacterial morphology by transmission electron microscopy, and growth inhibition by counting colony-forming units. RESULTS: H. pylori motility was diminished with RBC and BC but not R. However, the effect of RBC was markedly greater than that of BC at each bismuth concentration and time of exposure tested: (i) brief exposure to RBC/bismuth 50 microg/mL but not to BC, resulted in a significant loss of motility without loss of viability or change in cell morphology, and (ii) bacteria were immobilized, and lost viability after exposure to RBC/bismuth 50 microg/mL for 24 h but not to BC. Morphological destruction caused by RBC differed from that by BC: after 24 h exposure to the highest concentration tested, cell fragmentation and flagella detachment occurred more frequently with BC than RBC, but the latter produced greater disruption of intracellular structures. CONCLUSIONS: RBC suppresses growth of H. pylori, and has a specific inhibitory effect on the bacterial motor mechanism. These pharmacological actions are likely to contribute to the clinical effectiveness of the agent.

Measurement of motility of Helicobacter pylori, Campylobacter jejuni, and Escherichia coli by real time computer tracking using the Hobson BacTracker.

AIMS: (1) To make precise measurements and comparisons of various aspects of motility of three gastrointestinal pathogens, Helicobacter pylori, Campylobacter jejuni, and Escherichia coli, in log phase growth; (2) to provide background information on motility data to study the influence of pH, viscosity, and chemotactic factors, thereby gaining a better understanding of bacterial pathogenesis. METHODS: Computer image processing technology and phase contrast microscopy (Hobson BacTracker) were used to measure several indices of bacterial motility in real time. Ten clinical isolates of each species in log phase liquid culture were studied. RESULTS: C jejuni moved fastest, with a median curvilinear velocity (CLV) of 38.76 microns/s (range 29.08 to 52.82). Next was H pylori, median CLV 25.02 microns/s (range 12.07 to 29.07). E coli was the slowest, median CLV 12.73 microns/s (range 8.20 to 18.04). The straight line velocities showed similar trends. Measurement of track linearity (TL) showed that C jejuni moved the straightest (TL 60.3%), H pylori moved in wide circles (TL 28.7%), and E coli showed spinning movement without much linear displacement (TL 18.3%). There were significant differences in these three variables between the species studied, but no significant differences in measurements of time and frequency of halts between movement runs. CONCLUSIONS: The BacTracker provides a useful technical aid for measuring several indices of bacterial motility objectively, reproducibly, and precisely, which is difficult to achieve without computer assistance. Accurate quantification of motility provides a basis for studying the factors which influence bacterial motility. It can provide phenotypic measurements of the effect of flagellar gene depletion.

Motility of Helicobacter pylori in a viscous environment.

BACKGROUND: Patients with gastroduodenal disease produce gastric mucus of higher viscosity, and mucins that are of a smaller size, than normal. We have modelled these changes to the mucus layer in solutions of methylcellulose, and measured bacterial motility in biopsied mucus, to assess how they might influence the movements of Helicobacter pylori. METHODS: Motilities of Helicobacter pylori were measured in solutions of methylcellulose with molecular mass of 14 and 41 kDa, and in biopsied mucus with a Hobson BacTracker. Four parameters of bacterial motility were quantified: curvilinear velocity (CLV), path length, track linearity and curvature rate. RESULTS: All H. pylori were motile in methylcellulose solutions, and had optimal motilities at a viscosity of 3 cp (CLV in methylcellulose of 41 kDa, for instance, was 33 +/- 1.4 microm/s (mean +/- SEM) and the path length in methylcellulose of 41 kDa was 22.4 +/- 2 microm). At higher viscosities, mean CLVs, path lengths and curvature rates decreased, and track linearities increased in direct proportion to the increase in methylcellulose viscosity. Bacteria become non-motile at a viscosity of 50 cp in methylcellulose of 14 kDa, and at 70 cp in methylcellulose of 41 kDa. Mean CLVs, path lengths and curvature rates (but not track linearities) were greater in methylcellulose of 41 kDa than in methylcellulose of 14 kDa at each viscosity tested. Motilities of H. pylori from patients with duodenal ulcer or non-ulcer dyspepsia in methylcellulose solutions were not significantly different. H. pylori had poor motility in biopsied mucus, but became highly motile when biopsied mucus was diluted with saline. CONCLUSIONS: The viscosity-motility profiles of H. pylori in methylcellulose and the motilities of H. pylori in biopsied mucus suggest (1) that H. pylori may have poor motility in mucus at the epithelial surface, but high motility at the luminal surface of the mucus layer, and (2) that the increased mucus viscosity and decreased mucin size in patients with gastroduodenal disease act in combination to decrease H. pylori motility in vivo.

Oral administration of a water extract of Phytolacca dodecandra l'herit in mice--effects on reproduction.

Experiments were conducted to determine whether oral administration of a water extract of P. dodecandra had significant effects on reproduction in mice. The work is based on earlier reports in this journal that butanol extracts of the berries of this plant had spermatocidal properties in vitro and blastocidal activity when injected directly into the uterus of rabbits. The extract was supplied to groups of mice in the drinking water at predetermined concentrations (range 0-250 mg per liter) and treatment intervals (continuous and monthly). An analysis of variance was performed on the results of the following variables for all the groups: mean number of females giving birth in each treatment group, mean number of days taken to give birth, mean number of young born per group, and mean number of young surviving at four days post-parturition. The results indicated that there were no significant differences (p greater than 0.05) between all the groups on all of the parameters evaluated. From the results obtained a tentative conclusion was reached that bodies of water treated with molluscicidal concentrations (approximately 50-100 mg/liter) of P. dodecandra water extract, probably do not pose a great danger to reproduction in mice within the limits of the experimental conditions described.

Selective expansion and continuous culture of macrophages from adult pig blood.

Macrophages were selectively expanded and continuously cultured from adult pig blood. One-half ml of heparinized adult pig blood was inoculated directly into the medium overlaying a feeder layer of STO mouse fibroblasts. After attachment to the feeder cells for 24 h, the culture was washed several times with the medium to remove most of any unattached blood cells and re-fed. Approximately 7 x 10(4) blood monocytes were initially detected and enumerated by specific binding of DiI-labeled acetylated low density lipoprotein (DiI-Ac-LDL). Macrophage outgrowths appeared in the primary culture after 6-7 days. The macrophages grew to relatively high density in 2-3 weeks (2-3 x 10(6) cells/T25 flask), and the culture was passaged on to fresh STO feeder layers to begin secondary culture. Over 2-3 months of culture the macrophage replication produced as many as 1.4 x 10(9) DiI-Ac-LDL-positive cells. The macrophages grew on top of the feeder cells in two forms: either a semi-attached, round morphology, or a closely adherent, flat ameboid morphology with several extended pseudopods. Electron microscopic examination revealed the cells to be uniformly of macrophage character and that 4-5% were giant cells. The macrophages were phagocytic and expressed CD14 on their surfaces. They also reacted positively with pig macrophage-specific monoclonal antibody (mAb), and were negative for reactivity with pig T- and B-cell-specific mAb. This simple method for isolating and propagating macrophages may indicate the replicative capacity of either adult pig blood monocytes or circulating blood stem cells, and it may be useful in providing macrophages for general research, virological assay, adoptive-immunotherapy models, and somatic gene therapy models.

Continuous cultures of macrophages derived from the 8-day epiblast of the pig.

Secondary macrophage cell cultures were generated from the primary culture of epiblasts of 8-d-old pig blastocysts. The epiblast-derived macrophagelike (EDM) cells have a morphology and ameboid behavior that is typical of tissue histocytes. The cells reacted positively with monoclonal antibodies specific for pig granulocyte-macrophage lineage cells, and were not reactive with monoclonal antibodies specific for pig B and T lymphocytes. Marked phagocytic behavior and the formation of phagosomes were demonstrated following incubation with FITC-labeled bacteria. The EDM cells stained positively for nonspecific acid esterase that was not inhibited by sodium fluoride. DiI-acetylated-LDL was rapidly taken up by the cells. Transmission electron microscopy of the EDM cells showed phagolysosomes, numerous cytoplasmic vacuoles, large, lobed nuclei, and numerous pseudopods or filopodia at the cell surface. Strong reactivity of the cells with anti-CD14 monoclonal antibody was observed. Further, cytotoxic activity was produced from the EDM cells after exposure to lipopolysaccharide in a concentration and time-dependent manner. The cultures could be maintained and expanded for several months on STO co-culture. Their derivation from the epiblast of the pig demonstrates the possibility of obtaining hemopoietic cell cultures from the preimplantation blastocysts of all mammals.

Modulation of Fc receptors for IgG on bovine polymorphonuclear neutrophils by interferon-gamma through de novo RNA transcription and protein synthesis.

Polymorphonuclear neutrophils (PMN) from 4 cows were preincubated (30 minutes, 37 C) in either actinomycin D (100 micrograms/ml) or puromycin (10 micrograms/ml), inhibitors of mRNA transcription and protein translation, or in medium 199. The PMN were incubated for a further 4.5 hours in medium containing 100 U of recombinant bovine interferon-gamma (rboIfn-gamma). The PMN were then incubated with bovine IgG1, IgG2, IgM, or aggregated IgG (aIgG; 4 C, 12 hours) for flow cytometric analysis, using fluoresceinated isotype-specific antibody. The percentage of PMN binding the ligand and the logarithmic mean fluorescent channel (LMFC), an indicator of the amount of receptor (R) expression, were recorded. Competitive inhibition of ligand binding was measured by incubating PMN with fluoresceinated IgG2 in the presence or absence of 100-fold excess of IgG1, IgG2, and aIgG. Activation with rboIfn-gamma induced a 4.5-fold increase in binding of IgG1 and a fivefold increase in LMFC for IgG2. These increases were inhibited by actinomycin D and puromycin. Percentage of PMN binding aIgG decreased after activation by rboIfn-gamma. Interferon-gamma treatment did not affect binding or LMFC of IgM. However, binding of IgM was reduced by treatment with actinomycin D. Binding of fluoresceinated IgG2 was inhibited by unlabeled IgG1, IgG2, and aIgG. Results indicate that bovine PMN Fc receptors (FcR) for IgG1 and IgG2 were rboIfn-gamma inducible, that induction required de novo transcription and translation, that a heterogeneous population of FcR exist on bovine PMN, and that IgG1 and IgG2 share a common FcR. Further, bovine PMN are capable of gene activation and are responsive to changes in their environment, thus being amenable to modulation for effective pathogen destruction.

Effect of in vitro and in vivo migration of bovine neutrophils on binding and expression of Fc receptors for IgG2 and IgM.

Binding of endogenous and exogenous homologous IgG2 and IgM to bovine neutrophils before and after in vitro migration through micropore filters, and in vivo migration through mammary tissues after intramammary injection of endotoxin was evaluated by use of flow cytometry. Immunoglobulin binding to neutrophils at 4 and 37 C was also evaluated. Before and after in vitro migration, neutrophils with endogenously bound IgG2 and IgM averaged 1 and 2% and 23 and 7%, respectively. Before and after in vivo migration, IgG2 and IgM binding averaged 1 and 7% and 26 and 15%, respectively. Before and after in vitro migration, binding of purified IgG2 and IgM averaged 75 and 67% and 8 and 24%, respectively. Before and after in vivo migration, percentage of neutrophils binding purified IgG2 and IgM averaged 92 and 98% and 54 and 70%, respectively. When serum was used as a source of exogenous immunoglobulins, binding of total IgG after in vitro migration increased from 5% to 28% and of IgM from 4% to 20%. After in vivo migration, binding increased from 21% to 47% and from 24% to 56%, respectively. Exogenous binding of IgG2 at 4 and 37 C averaged 75 and 84%, and binding of IgM averaged 8% at either temperature. Endogenous IgG2 was unaffected by temperature, however, binding of IgM decreased from 23% at 4 C to 2% at 37 C. These data indicate that endogenous binding was higher for IgM before migration than after migration, in vitro and in vivo. Furthermore, migration in vivo through cellular matrices induced receptor upregulation for IgG and IgM.(ABSTRACT TRUNCATED AT 250 WORDS)

Complement component C3b and immunoglobulin Fc receptors on neutrophils from calves with leukocyte adhesion deficiency.

Receptors for opsonins, such as complement component C3b (CR1) and immunoglobulins, Fc receptors, interact with adhesion glycoproteins in mediating immune functions. Defects in expression of the adhesion glycoproteins CD11/CD18 results in severely hampered in vitro and in vivo adherence-related functions of leukocytes. Little is known regarding the effect of leukocyte adhesion deficiency (LAD) on ligand binding and receptor expression. We investigated the binding and expression of CR1 and Fc receptors by bovine neutrophils isolated from dairy calves suffering from LAD, compared with clinically normal (hereafter referred to as normal) age-matched calves. Neutrophils were also assayed for endogenously bound IgG and IgM and for exogenous binding of C3b, IgG1, IgG2, IgM, and aggregated IgG (aIgG), using flow cytometry. Luminol-enhanced chemiluminescence (CL) production in response to IgG2 opsonized zymosan was studied, and specific inhibition of CL was used to determine the specificity of IgG2 binding. Activation of protein kinase C with phorbol myristate acetate was used to determine the effect of cellular activation on expression of CR1. A greater percentage of neutrophils from normal calves bound C3b than did neutrophils from LAD-affected calves. Receptor expression was similar. Activation with phorbol myristate acetate resulted in increased expression of CR1 on neutrophils from normal and LAD-affected calves, but expression was almost twofold greater on neutrophils from normal calves. There was no difference between LAD-affected and normal calves in percentage of neutrophils that bound endogenous IgG and IgM. A greater percentage of neutrophils from normal calves bound exogenous IgM than did neutrophils from LAD-affected calves.(ABSTRACT TRUNCATED AT 250 WORDS)

Sequential transformation of mesenchymal stem cells is associated with increased radiosensitivity and reduced DNA repair capacity.

We used sequentially transformed mesenchymal stem cells to investigate how the events that lead to tumorigenicity influence the cellular response to radiation. Bone marrow derived SH2(+), SH4(+), Stro-1(+) mesenchymal stem cells (MSC) were transformed stepwise by retroviral transfection of hTERT, HPV-16 E6 and E7, SV40 small T antigen and oncogenic H-ras. Cells at three different stages of transformation were irradiated and compared using assays for cytotoxicity, apoptosis, DNA double-strand break (DSB) repair and checkpoint signaling. The effects of inhibition of cell cycle checkpoint signaling on radiosensitivity were investigated using RNA interference. During stepwise transformation, specifically after HPV-16 E6 and E7 transduction, MSCs became more sensitive to radiation. This was associated with increased residual DNA DSB at 24 h and increased apoptosis. Enhanced checkpoint signaling occurred during transformation and there was a differential effect of checkpoint targeting in cells at different stages; Chk1 knockdown enhanced radiosensitivity in all cells while Chk2 knockdown only affected non-transformed cells. These data show that transformation of MSC is associated with a reduction in DNA DSB repair capacity and increased radiosensitivity. Up-regulation of checkpoint signaling does not overcome this and the effect of checkpoint inhibition may change with transformation status.

Bioconversion of glycerol to ethanol by a mutant Enterobacter aerogenes.

The main objective of this research is to develop, by adaptive evolution, mutant strains of Enterobacter aerogenes ATCC 13048 that are capable of withstanding high glycerol concentration as well as resisting ethanol-inhibition. The mutant will be used for high ethanol fermentation from glycerol feedstock. Ethanol production from pure (P-) and recovered (R-) glycerol using the stock was evaluated. A six-tube-subculture-generations method was used for developing the mutant. This involved subculturing the organism six consecutive times in tubes containing the same glycerol and ethanol concentrations at the same culture conditions. Then, the glycerol and/or ethanol concentration was increased and the six subculture generations were repeated. A strain capable of growing in 200 g/L glycerol and 30 g/L ethanol was obtained. The ability of this mutant, vis-à-vis the original strain, in utilizing glycerol in a high glycerol containing medium, with the concomitant ethanol yield, was assessed. Tryptic soy broth without dextrose (TSB) was used as the fermentation medium. Fermentation products were analyzed using HPLC.In a 20 g/L glycerol TSB, E. aerogenes ATCC 13048 converted 18.5 g/L P-glycerol and 17.8 g/L R-glycerol into 12 and 12.8 g/L ethanol, respectively. In a 50 g/L P-glycerol TSB, it utilized only 15.6 g/L glycerol; but the new strain used up 39 g/L, yielding 20 g/L ethanol after 120 h, an equivalence of 1.02 mol ethanol/mol-glycerol. This is the highest ethanol yield reported from glycerol bioconversion. The result of this P-glycerol fermentation can be duplicated using the R-glycerol from biodiesel production.

Comparison of two enzyme immunoassays to culture for the diagnosis of chlamydial conjunctivitis and respiratory infections in infants.

Data are limited for the performance of enzyme immunoassays for the detection of Chlamydia trachomatis in conjunctival and nasopharyngeal specimens from infants. The only available data are for one assay, Chlamydiazyme (Abbott Diagnostics). The purpose of this study was to compare a new enzyme immunoassay, Pathfinder (Kallestad Diagnostics), with Chlamydiazyme and culture for the diagnosis of chlamydial conjunctivitis and pneumonia in infants. Pathfinder differs from Chlamydiazyme in that it uses a monoclonal antibody directed against the chlamydial lipopolysaccharide in addition to a polyclonal antichlamydial antibody. Triplicate conjunctival and nasopharyngeal specimens were obtained from 97 infants with conjunctivitis, and additional nasopharyngeal specimens were obtained from 14 infants with suspected chlamydial pneumonia (total, 111 nasopharyngeal specimens). Twenty-nine (30%) of the conjunctival specimens from infants with conjunctivitis and four (28.6%) of the nasopharyngeal specimens from the infants with pneumonia were positive for C. trachomatis by cell culture. The sensitivities, specificities, and positive and negative predictive values for Pathfinder for conjunctival specimens were 96.6, 98.5, 96.6, and 98.5%, respectively. The results for Chlamydiazyme were 96.6, 100, 100, and 98.6%, respectively. For nasopharyngeal specimens, the results for Pathfinder were 77.8, 94.6, 73.7, and 95.7%, respectively. The results for Chlamydiazyme were 66.7, 95.7, 75, and 93%, respectively. Pathfinder and Chlamydiazyme appeared to perform equivalently for the detection of C. trachomatis in both eye and nasopharyngeal specimens from infants with chlamydial conjunctivitis and pneumonia.

Comparison of Kodak Surecell Chlamydia Test Kit with culture for the diagnosis of chlamydial conjunctivitis in infants.

The accuracy of the Surecell Chlamydia Test Kit (Kodak Clinical Products, Rochester, N.Y.) in detecting neonatal conjunctival infection caused by Chlamydia trachomatis was determined by comparison of this enzyme immunoassay with the isolation of C. trachomatis in tissue culture. Kodak Surecell is a rapid monoclonal antibody-based membrane capture enzyme immunoassay which can be processed in the office of a physician. The sensitivity and specificity compared to culture in detecting C. trachomatis in conjunctival specimens from infants with conjunctivitis were 93 and 96%, respectively. The test does not require specialized equipment or trained personnel and would be ideal for physicians who see low numbers of infants with possible chlamydial conjunctivitis in their offices.

Comparison of a chemiluminometric immunoassay with culture for diagnosis of chlamydial infections in infants.

The performance of Magic Lite (CIBA-Corning), a chemiluminescent immunoassay (CIA), was compared with that of culture for the diagnosis of neonatal chlamydial conjunctivitis and respiratory infection. We performed a retrospective evaluation of 51 ocular and 96 nasopharyngeal specimens previously collected for culture testing with the CIA. The sensitivities for the ocular and the nasopharyngeal specimens were 91 and 91.7%, respectively. The specificities for both sites were 100%. A subsequent prospective study evaluating 71 ocular and 38 nasopharyngeal specimens revealed sensitivities of 83.3 and 20%, respectively. The specificities for both sites were 100%. The CIA performed favorably, compared with culture, for the diagnosis of chlamydial conjunctivitis; however, the CIA appeared less sensitive for the diagnosis of respiratory infection, including pneumonia.

Comparison of two rapid microscopic methods and culture for detection of Chlamydia trachomatis in ocular and nasopharyngeal specimens from infants.

The data available for the diagnosis of chlamydial infections in infants which compare direct fluorescent-monoclonal-antibody stains (DFAs) with culture are limited to one reagent, MicroTrak (Syva Inc., Palo Alto, Calif.). We therefore performed a comparison of Pathfinder (Kallestad Diagnostics, Chaska, Minn.) and MicroTrak with chlamydia culture. Paired conjunctival and nasopharyngeal specimens for DFAs and cultures were obtained from 56 infants less than 1 month of age with conjunctivitis. The sensitivities for detecting C. trachomatis in conjunctival specimens with MicroTrak and Pathfinder were 93.8 and 88.2%, respectively, and the specificities were 87.5 and 94.9%, respectively. The DFA tests on nasopharyngeal specimens from infants with conjunctivitis did not perform as well. The sensitivities for Pathfinder and MicroTrak were 33 and 50%, respectively. There were a total of six patients with culture-positive chlamydial conjunctivitis whose nasopharyngeal specimens were DFA positive and culture negative; four of the specimens were positive by both DFAs. These six discordant specimens were further evaluated by preparing pellets and smears of the original culture specimens. All six contained typical fluorescing elementary bodies when stained with the Syva DFA reagent.