A Comparison of Pneumococcal Nasopharyngeal Carriage in Very Young Fijian Infants Born by Vaginal or Cesarean Delivery

IMPORTANCE

Pneumococcal nasopharyngeal carriage is a prerequisite for pneumococcal disease. The main transmission route is from toddlers, who commonly carry pneumococci. However, neonatal pneumococcal disease case reports suggest that vertical pneumococcal transmission may also occur.

OBJECTIVE

To describe and compare pneumococcal nasopharyngeal carriage and density by infant mode of delivery in young Fijian infants.

DESIGN, SETTING, AND PARTICIPANTS

Annual cross-sectional surveys were performed in Suva, Fiji, before the introduction of 10-valent pneumococcal conjugate vaccine (PCV10), from September 14 to December 20, 2012, and after PCV10 was introduced, from July 11 to November 19, 2013; July 15 to December 9, 2014; and August 13 to November 19, 2015. Caregivers of 2006 infants aged 5 to 8 weeks participated in the surveys. Statistical analysis was performed from May 24, 2018, to August 12, 2019.

EXPOSURES

Caregivers provided data on infant mode of delivery and demographics via interviewer-led survey.

MAIN OUTCOMES AND MEASURES

Pneumococci in swab samples were detected and quantified by lytA quantitative polymerase chain reaction with molecular serotyping by microarray. Pneumococci were categorized as PCV10 or non-PCV10 serotypes.

RESULTS

Of the 2006 infants (976 girls and 1030 boys; mean [SD] age, 6.1 [0.02] weeks]), 1742 (86.8%) were born vaginally and 264 were born by cesarean delivery. Infants delivered vaginally, compared with those born by cesarean delivery, had a higher prevalence of overall pneumococcal nasopharyngeal carriage (470 of 1722 [27.3%; 95% CI, 25.2%-29.4%] vs 47 of 260 [18.1%; 95% CI, 13.6%-23.3%]; P = .002), PCV10 carriage (113 of 1698 [6.7%; 95% CI, 5.5%-7.9%] vs 8 of 256 [3.1%; 95% CI, 1.4%-6.1%]; P = .03), and non-PCV10 carriage (355 of 1698 [20.9%; 95% CI, 19.0%-22.9%] vs 38 of 256 [14.8%; 95% CI, 10.7%-19.8%]; P = .02), and had higher median densities of overall pneumococci (4.9 log10 genome equivalents [GE]/mL [interquartile range, 4.8-5.0 log10 GE/mL] vs 4.5 log10 GE/mL [interquartile range, 4.1-4.6 log10 GE/mL]; P = .01) and non-PCV10 pneumococci (4.9 log10 GE/mL [interquartile range, 4.7-5.0 log10 GE/mL] vs 4.4 log10 GE/mL [interquartile range, 4.0-4.7 log10 GE/mL]; P = .01). Vaginal delivery was associated with overall (adjusted odds ratio, 1.57 [95% CI, 1.10-2.23]; P = .01) and non-PCV10 (adjusted odds ratio, 1.49 [95% CI, 1.01-2.20]; P = .04]) pneumococcal nasopharyngeal carriage. Vaginal delivery was not associated with PCV10 carriage (adjusted odds ratio, 1.67 [95% CI, 0.80-3.51]; P = .17). After adjustment, vaginal delivery was not associated with density.

CONCLUSIONS AND RELEVANCE

Pneumococcal nasopharyngeal carriage prevalence and density were higher in infants delivered vaginally compared with those delivered by cesarean birth. After adjustment, vaginal delivery was associated with pneumococcal carriage. Differences in carriage by mode of delivery may be due to differential exposure to the vaginal microbiota during delivery and the effect of intrapartum antibiotics during cesarean delivery on the infant microbiome. Our findings also raise the hypothesis that vertical transmission may contribute to pneumococcal acquisition.

Epidemiology and risk factors for typhoid fever in Central Division, Fiji, 2014-2017: A case-control study

Background

Typhoid fever is endemic in Fiji, with high reported annual incidence. We sought to identify the sources and modes of transmission of typhoid fever in Fiji with the aim to inform disease control.

Methodology/Principal findings

We identified and surveyed patients with blood culture-confirmed typhoid fever from January 2014 through January 2017. For each typhoid fever case we matched two controls by age interval, gender, ethnicity, and residential area. Univariable and multivariable analysis were used to evaluate associations between exposures and risk for typhoid fever. We enrolled 175 patients with typhoid fever and 349 controls. Of the cases, the median (range) age was 29 (2–67) years, 86 (49%) were male, and 84 (48%) lived in a rural area. On multivariable analysis, interrupted water availability (odds ratio [OR] = 2.17; 95% confidence interval [CI] 1.18–4.00), drinking surface water in the last 2 weeks (OR = 3.61; 95% CI 1.44–9.06), eating unwashed produce (OR = 2.69; 95% CI 1.48–4.91), and having an unimproved or damaged sanitation facility (OR = 4.30; 95% CI 1.14–16.21) were significantly associated with typhoid fever. Frequent handwashing after defecating (OR = 0.57; 95% CI 0.35–0.93) and using soap for handwashing (OR = 0.61; 95% CI 0.37–0.95) were independently associated with a lower odds of typhoid fever.

Conclusions

Poor sanitation facilities appear to be a major source of Salmonella Typhi in Fiji, with transmission by drinking contaminated surface water and consuming unwashed produce. Improved sanitation facilities and protection of surface water sources and produce from contamination by human feces are likely to contribute to typhoid control in Fiji.

Modeling suggests that Oceania has surpassed Asia and sub-Saharan Africa as the region with the highest typhoid fever incidence. While Pacific Islands are often neglected due to small population sizes, there is an urgent need to understand the epidemiology of typhoid fever in the region. Fiji, an upper-middle income country in Oceania, has reported an increase in typhoid fever notifications over the last decade. However, the epidemiology of typhoid fever in Fiji is incompletely understood due to gaps in surveillance and lack of epidemiological research on local risk factors. We conducted a case-control study in the Central Division of Fiji to help inform prevention and control strategies. We found unimproved sanitation facilities to be major source of typhoid fever in Fiji, with transmission by drinking contaminated surface water and consumption of unwashed produce. We also found an association between poor water availability and poor hygiene with typhoid fever. Improvements in sanitation facilities to protect surface water and produce from contamination are likely to contribute to improved typhoid control in Fiji. Because of the distinct socio-demographic and environmental conditions found in Oceania, our findings may reflect sources and modes of transmission predominant elsewhere in the region.

Real-time qPCR improves meningitis pathogen detection in invasive bacterial-vaccine preventable disease surveillance in Fiji

As part of the World Health Organization Invasive Bacterial-Vaccine Preventable Diseases (IB-VPD) surveillance in Suva, Fiji, cerebrospinal fluid (CSF) samples from suspected meningitis patients of all ages were examined by traditional methods (culture, Gram stain, and latex agglutination for bacterial antigen) and qPCR for Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Of 266 samples tested, pathogens were identified in 47 (17.7%). S. pneumoniae was the most common pathogen detected (n = 17) followed by N. meningitidis (n = 13). The use of qPCR significantly increased detection of IB-VPD pathogens (P = 0.0001): of 35 samples that were qPCR positive for S. pneumoniae, N. meningitidis, and H. influenzae, only 10 were culture positive. This was particularly relevant for N. meningitidis, as only 1/13 cases was culture positive. Molecular serotyping by microarray was used to determine pneumococcal serotypes from 9 of 16 (56%) of samples using DNA directly extracted from CSF specimens. Results indicate that qPCR significantly increases detection of S. pneumoniae, N. meningitidis, and H. influenzae in CSF, and that application of molecular diagnostics is a feasible way to enhance local and global surveillance for IB-VPD.

Climate change and freshwater ecosystems in Oceania: an assessment of vulnerability and adaptation opportunities

Human-forced climate change significantly threatens the world’s freshwater ecosystems, through projected changes to rainfall, temperature and sea level. We examined the threats and adaptation opportunities to climate change in a diverse selection of rivers and wetlands from Oceania (Australia, New Zealand and Pacific Islands). We found common themes, but also important regional differences. In regulated floodplain rivers in dry regions (i.e. Australia), reduced flooding projected with climate change is a veneer on current losses, but impacts ramp up by 2070. Increasing drought threatens biota as the time between floods extends. Current measures addressing water allocations and dam management can be extended to adapt to climate change, with water buy-back and environmental flows critical. Freshwater wetlands along coastal Oceania are threatened by elevated salinity as sea level rises, potentially mitigated by levee banks. In mountainous regions of New Zealand, the biodiversity of largely pristine glacial and snow melt rivers is threatened by temperature increases, particularly endemic species. Australian snow melt rivers face similar problems, compounding impacts of hydro-electric schemes. Translocation of species and control of invasive species are the main adaptations. Changes to flow regime and rising water temperatures and sea levels are the main threats of climate change on freshwater ecosystems. Besides lowering emissions, reducing impacts of water consumption and protecting or restoring connectivity and refugia are key adaptations for conservation of freshwater ecosystems. Despite these clear imperatives, policy and management has been slow to respond, even in developed regions with significant resources to tackle such complex issues.

Studies of the aggregation behavior of cyclic gemini surfactants

The specific conductance, surface tension, mean aggregation number, and apparent molar volume properties of aqueous solutions of a novel series of N,N'-bis(cyclododecyldimethyl)-alpha,omega-alkanediammonium dibromide (c12-s-c12) surfactants, where s is the spacer chain length, are reported. Surfactants with s = 3, 4, and 6 have been prepared and characterized in terms of their Krafft temperature (T(Kr)), critical micelle concentration (cmc), surfactant head group area (a) at the air-water interface, mean aggregation number (N(agg)), and the volume change upon micelle formation (deltaV(phi,M)). The c12-3-c12 shows little evidence of aggregate formation, while the results obtained for the c12-4-c12 and c12-6-c12 homologues suggest the formation of small, poorly defined micellar aggregates in aqueous solution.

Evidence that a New Antibiotic Flavone Glycoside Chemically Defends the Sea Grass Thalassia testudinum against Zoosporic Fungi

[This corrects the article on p. 1491 in vol. 64.].

Evidence that a New Antibiotic Flavone Glycoside Chemically Defends the Sea Grass Thalassia testudinum against Zoosporic Fungi

Significantly fewer thraustochytrid protists (zoosporic fungi) were observed in association with healthy leaf tissue of the marine angiosperm Thalassia testudinum than in association with sterilized samples that were returned to the collection site for 48 h. In support of the hypothesis that sea grass secondary metabolites were responsible for these differences, extracts of healthy T. testudinum leaf tissues inhibited the growth of the co-occurring thraustochytrid Schizochytrium aggregatum and deterred the attachment of S. aggregatum motile zoospores to an extract-impregnated substrate. By using S. aggregatum for bioassay-guided chemical fractionation, a new flavone glycoside was isolated and structurally characterized as luteolin 7- O -β- d -glucopyranosyl-2"-sulfate. Whole-leaf tissue concentrations of this metabolite (4 mg/ml of wet leaf tissue) inhibited S. aggregatum attachment, and a significantly lower concentration (270 μg/ml) reduced thraustochytrid growth by 50%, suggesting that natural concentrations are at least 15 times greater than that needed for significant microbiological effects. These results offer the first complete chemical characterization of a sea grass sulfated flavone glycoside and provide evidence that a secondary metabolite chemically defends T. testudinum against fouling microorganisms.

Application of total organic carbon analysis to cleaning validation

Cleaning validation is the process of assuring that cleaning procedures effectively remove residue from manufacturing equipment/facilities below a predetermined level. This is necessary to assure the quality of future products using the equipment, to prevent cross-contamination and as a GMP requirement. Currently, cleaning validation samples are measured using HPLC or spectrophotometric methods of analysis which are often time consuming and subject to a number of interferences. Total Organic Carbon (TOC) analysis is a new method which has previously only been applied to measurement of carbon residues on production surfaces for biopharmaceuticals. We have applied the TOC analysis method to a number of traditional pharmaceutical products including antibiotics, steroids, and antinauseants in addition to biopharmaceuticals. The method offers extremely low detection capability (ppm and ppb), rapid sample analysis time and therefore quick turn-around of production equipment and facilities. TOC analysis is also applicable to on-line analysis. The method allows the measurement of extraneous materials such as process intermediates, cleaning agents, and protein materials not possible by other methods.

In vitro evaluation of the plasma and blood compatibility of a parenteral formulation for ditekiren, a novel renin inhibitor pseudopeptide

Ditekiren (U-71038; Boc-Pro-Phe-N-MeHis-Leu-psi[CHOHCH2]-Val-Ile-(aminomethyl)pyridine ) is a potent renin inhibitor peptide and was formulated for clinical intravenous administration in acidified dextrose. This formulation of ditekiren was evaluated in vitro with human and monkey plasma as to its potential for forming a precipitate either of drug or of plasma proteins. Analysis by centrifugation showed that no drug precipitation occurred in plasma from either species at concentrations 25 times higher than anticipated in clinical studies. Results obtained by turbidimetry indicated that formulated ditekiren did not cause aggregation of human platelets or flocculation of proteins at concentrations approaching the solubility limit of the drug in plasma. Ditekiren or vehicle also caused no detectable lysis of red cells at concentrations representing 10 times the maximum clinical level. Therefore, ditekiren solutions as formulated are judged completely compatible with blood and plasma upon clinical intravenous administration.

Derivatization of primary amines by 2-naphthalenesulfonyl chloride for high-performance liquid chromatographic assay of neomycin sulfate

A normal phase high-performance liquid chromatographic (HPLC) method has been developed for the assay of neomycin sulfate. The method involves pre-column derivatization with 2-naphthalenesulfonyl chloride (NSCl) followed by extraction in chloroform and chromatography using a normal phase silica column with detection at 254 nm. The standard curve for the HPLC assay of neomycin sulfate is linear with a correlation coefficient of 0.9996 over the range of 0.02 to 0.4 mg/ml. Neomycins B, and C, and neamine can be separated and quantified isocratically with relative standard deviations of 0.92% and 1.4% for neomycin (B + 1/2C) and neamine, respectively. Prednisolone is used as an internal standard to aid in quantification. Mass spectrometric data confirms that neomycin is derivatized at all the six primary amines on the neomycin molecule. Eight lots of neomycin sulfate were used to compare the HPLC [NSCl and 1-fluoro-2,4-dinitrobenzene (DNFB)], gas-liquid chromatographic and microbiological assay methods. The average results of the NSCl-HPLC method fell between those of the microbiological and DNFB-HPLC methods. Also, good correlation of the neomycin C contents in neomycin were obtained between the NSCl-HPLC and DNFB-HPLC methods.

Derivatization of secondary amines with 2-naphthalene-sulfonyl chloride for high-performance liquid chromatographic analysis of spectinomycin

A normal-phase high-performance liquid chromatographic (HPLC) method has been developed for the assay of spectinomycin hydrochloride and spectinomycin sulfate for detection at 254 nm. The method involves pre-column derivatization of secondary amines of spectinomycin with 2-naphthalenesulfonyl chloride (NSCl) using a catalyst. Lincomycin, 1-methylpyrrole, 2-acetyl-1-methylpyrrole, and 2-acetyl-pyrrole act as catalysts for sulfonylation of spectinomycin. Without a catalyst, the derivatization reaction forms a considerable amount of actinospectinoic acid, a degradation compound of spectinomycin, and peak area:weight ratio of the derivative is approximately 15% lower than those with the catalyst. Following derivatization the sample is extracted and chromatographed on a normal-phase silica column with detection at 254 nm. The method is applicable for the analysis of both the hydrochloride and sulfate salt forms of spectinomycin. All the known degradation compounds of spectinomycin such as actinamine, actinospectinoic acid and the biosynthesis intermediates, dihydrospectinomycin diastereoisomers, are completely separated with this method. Mass spectrometric data confirms that spectinomycin is derivatized with NSCl at the secondary amines located at positions 6 and 8 of the ring structure. The standard curves for the HPLC assay of spectinomycin hydrochloride and sulfate are linear with correlation coefficients of 0.9997 and 0.9999, respectively over the range of 0.05 mg/ml to 0.3 mg/ml. The relative standard deviations (R.S.D.) of the HPLC assay methods for spectinomycin hydrochloride and sulfate are 0.67% and 0.86%, respectively. Spectinomycin hydrochloride and sulfate bulk drugs were assayed by the HPLC method and compared to gas-liquid chromatography and microbiological assay results. The HPLC method was used to assay spectinomycin in a veterinary formulation, Linco-Spectin soluble powder. The sensitivity of the HPLC assay was determined to be approximately 4 ng sample load on the column, which suggests applicability in serum and residue level studies.

Human intestinal mononuclear cells. II. Demonstration of a naturally occurring subclass of T cells which respond in the allogeneic mixed leukocyte reaction but do not effect cell-mediated lympholysis

We have examined the T-cell functional capabilities of human intestinal mononuclear cells isolated from surgically obtained normal and inflammatory bowel disease intestinal specimens. Intestinal mononuclear cells have T cells present which respond to the mitogenic lectins E-PHA, Con A, and PWM and to foreign cell-surface antigens in the allogeneic-mixed leukocyte reaction. Intestinal mononuclear cells from ulcerative colitis patients exhibit a significantly decreased responsiveness in comparison to normal intestinal mononuclear cells with regard to both mitogenesis and the allogeneic-mixed leukocyte reaction; however, these defects may be secondary to the severity of the disease process that led to intestinal resection or the therapy which patients had received. Although both normal and inflammatory bowel disease intestinal mononuclear cells exhibit responsiveness in the allogeneic-mixed leukocyte reaction, thus indicating recognition of and sensitization by foreign cell-surface determinants, intestinal mononuclear cells do not subsequently kill the sensitizing cells in cell-mediated lympholysis. Therefore, the subclass of T cells which mediates cell-mediated lympholysis may either be absent from intestinal mononuclear cells or nonfunctional, while the subclass of T cells which responds in the allogeneic-mixed leukocyte reaction is both present and functional. This observation adds to the evidence of major functional differences between intestinal and peripheral blood mononuclear cells. Therefore, it will be necessary to better understand the factors regulating the effector capabilities of intestinal mononuclear cells before delineation of immunopathologic events in these tissues.