Infants were randomly allocated at less than 48 hours of age to: 6 weeks of zidovudine monotherapy; or 6 weeks of zidovudine with three doses of nevirapine in the first week of life; or 6 weeks of zidovudine, with nelfinavir and lamivudine for 2 weeks. Overall in this high-risk group the HIV transmission rate was 8.5%, and in multivariate analysis only ART arm and maternal viral load were significantly associated with transmission. For infants uninfected at birth, transmission was two-fold higher in the zidovudine-alone

arm compared to the multiple ART arms (P = 0.034). There was no significant difference in transmission rates between the two multiple ARV arms and neonatal neutropenia was significantly

higher in the three-drug arm. In a randomized African study, babies born to mothers presenting at delivery received single-dose nevirapine or single-dose nevirapine and 1 week of zidovudine. Of those HIV negative at Obeticholic Acid in vivo birth, 34 (7.7%) who received nevirapine plus zidovudine and 51 (12.1%) who received nevirapine alone were infected (P = 0.03): a protective efficacy of 36% for the dual combination [279]. However, in two other randomized African studies where the mothers received find more short-course ART, for infants uninfected at birth there was no significant difference in transmission rate at 6 weeks for dual versus monotherapy short-course regimens to the infant: zidovudine plus lamivudine versus nevirapine [280]; or zidovudine plus nevirapine versus nevirapine [281]. PEP for the infant of an untreated mother should be given as soon as possible after delivery. There are no studies of time of initiation of combination PEP, but in a US cohort study a significantly reduced risk of transmission was only observed in infants commenced on zidovudine when this was started within 48 hours of birth [158]. For this reason, infant

Carbohydrate PEP should only be started where a mother is found to be HIV positive after delivery if it is within 48–72 hours of birth. NSHPC data from the UK and Ireland 2001–2008 demonstrate how the clinical practice of combination PEP in neonates has increased over time [282]. In total, 99% of 8205 infants received any PEP, and for the 86% with data on type of PEP, 3% received dual and 11% triple. The use of triple PEP increased significantly over this period, from 43% to 71% for infants born to untreated women, and from 13% to 32% where mothers were viraemic despite cART. HIV infection status was known for 89% of infants with information on PEP; 14.7% of infants who received no PEP were infected (5 of 34, all born vaginally to untreated mothers), compared to 1% of those who received any PEP (72 of 7286). Among infants born vaginally to untreated mothers, those who received PEP were significantly less likely to be infected than those who did not (8.5% [4/47] vs. 45.5% [5/11], P = 0.002).

To provide further evidence that the additional bands represent supercoiled plasmid multimers, the putative dimer was isolated from a gel and partially this website digested

with PstI. As indicated in Fig. 2a, digestion of the putative dimer led, at low PstI concentrations, to formation of a linear fragment with twice the size of the completely digested plasmid. This fragment is expected if just one PstI site of the dimer is cleaved. Addition of more enzyme led to the formation of the same product as observed for the monomer. Moreover, the DNA topology was analysed by agarose gel electrophoresis in the presence of chloroquine. This intercalating agent differentially affects the electrophoretic mobility of DNA containing distinct numbers of supercoils resulting in characteristic ladders. In contrast, linear or nicked DNA molecules migrate in the presence of chloroquine also as single bands (Molloy et al., 2004). As expected, in the absence of chloroquine, the isolated monomer and dimer migrated, like linearized DNA, as single bands

(Fig. 2b, left panel; the trace amounts of open circle and linearized molecules present in the preparations selleck chemicals llc of pHW126ΔHH2 monomer and dimer originate from shearing forces during DNA purification). The linearized fragment showed one single band in the presence of chloroquine, while the plasmid monomer and dimer displayed a multiple band pattern as expected for supercoiled DNA. A similar effect was also observed for the trimer (data not shown). These results confirm that deletion of the accessory region induces rapid formation of supercoiled plasmid multimers. Quantification of the different forms revealed that the DNA isolated from cells freshly transformed with monomeric pHW126ΔHH2 consisted

of approximately 34% monomers, 41% dimers, 16% trimers and 10% tetramers or higher multimers. As mentioned earlier, a copy number of approximately 8 has been reported for the constructs shown in Fig. 1a (Rozhon et al., 2011). However, qPCR measures only the number of pHW126-units per genome. Taking the multimerization of constructs Acetophenone lacking the accessory region into account, their number of physically independent plasmid molecules per cell is significantly lower, particularly < 5 per genome, providing an explanation for the increased plasmid loss rate. To map the genetic elements necessary for maintaining pHW126 in its monomeric state, we prepared a number of truncated versions of pHW126. The constructs pHW126ΔHH2 to pHW126-80 could replicate autonomously, while plasmids with larger deletions (pHW126-81 to pHW126-84) were replication deficient (Fig. 3a and b). This is in good agreement with a previous study, which showed that the HpaII-SpeI fragment contains the origin of replication (Rozhon et al., 2011). However, the data presented here have an improved resolution and allow assigning the 5′ end of the origin of replication to base pair 1689 (previously: 1669).

Despite this, HIV-positive patients continue to smoke. Several reasons have been suggested, including social conditions, polysubstance abuse, psychiatric comorbidities, physical and mental distress, poor access to smoking cessation interventions and poor adherence to such treatments, as well as the negative perception of long-term survival among HIV-positive patients [3,5,21]. The health benefits of stopping cigarette smoking in the general population are substantial and widely documented. The risk of coronary heart disease (CHD) and mortality is considerably reduced within the first 2 years of stopping smoking [22–27], and in some studies has been shown to return

to levels observed GSK1120212 manufacturer in nonsmokers within 5 years [22,23,25]. Whether HIV-positive patients also benefit from stopping smoking in 17-AAG cell line terms of cardiovascular and mortality risk has not previously been investigated, although recent data have demonstrated a reduced risk of bacterial pneumonia after at least 1 year of having ceased smoking [28]. If similar evidence observed in the general HIV-negative population could be demonstrated

in HIV-positive populations, then this may provide an additional incentive to stop smoking. The D:A:D study is a large international prospective cohort study with detailed follow-up information on incident CVD and smoking status. Our objective was to estimate the rates of CVD events and mortality after smoking cessation in HIV-positive patients participating in the D:A:D study. The D:A:D study is a prospective, multi-cohort observational collaborative study that includes 11 previously established cohorts in which 33 308 patients are followed at 212 clinics in Europe, Argentina, Australia and the USA. The primary objective of the study is to investigate the possible association between cART and the risk of MI. At the time of enrolment in the D:A:D study, patients were under active follow-up at the individual cohorts, and were included in D:A:D irrespective of whether or not and for how long they were receiving antiretroviral therapy (ART). Data were collected as part of their routine

clinical care and include demographic Tangeritin and other prospectively collected data such as age, sex, body mass index (BMI), hepatitis B and C status, history of CVD, diabetes mellitus (DM) status, family history of CVD, data on cigarette smoking, blood pressure therapy, DM therapy and lipid-lowering and antihypertensive therapy, and serum lipid levels. HIV-related core clinical data collected include mode of HIV transmission risk group, ART medication received, CD4 cell count, viral load and all clinical AIDS diagnoses. A detailed description of the study methodology has been given previously [17]. Ethical approval has been gained by the individual D:A:D collaborating cohorts from their local Institutional Review Boards (IRBs) as required.

One class of cells had an initial standing signal indicative of high extracellular H+ adjacent to

the cell membrane; challenge with glutamate, kainate or high extracellular potassium induced an extracellular alkalinization. This alkalinization was reduced by the calcium channel blockers nifedipine and cobalt. A second class of cells displayed RG7204 chemical structure spontaneous oscillations in extracellular H+ that were abolished by cobalt, nifedipine and low extracellular calcium. A strong correlation between changes in intracellular calcium and extracellular proton flux was detected in experiments simultaneously monitoring intracellular calcium and extracellular H+. A third set of cells was characterized by a standing extracellular alkalinization which was turned into an acidic signal by cobalt. In this last set of cells, addition of glutamate or high extracellular potassium did not significantly alter the proton signal. Taken together, the response characteristics of all three sets of neurons are most parsimoniously explained by activation of a plasma membrane Ca2+ ATPase pump, with an extracellular alkalinization resulting from exchange of intracellular calcium for extracellular H+. These findings argue strongly against the hypothesis that H+ release from horizontal cells AZD1208 mouse mediates lateral

inhibition in the outer retina. “
“Tricyclic antidepressants (TCAs) have been used to treat melancholic depression, which has been associated

with elevated hypothalamic–pituitary–adrenocortical (HPA) axis activity, whereas patients suffering from atypical depression, which is often associated with decreased HPA axis activity, show preferential responsiveness to monoamine oxidase inhibitors (MAOIs). We previously reported drug-specific effects of the TCA imipramine and the MAOI phenelzine Arachidonate 15-lipoxygenase on HPA axis-relevant endpoints in mice that may explain differential antidepressant responses in melancholic vs. atypical depression. However, selective serotonin reuptake inhibitors (SSRIs) are reported to be effective in both melancholic and atypical depression. We therefore hypothesized that SSRIs would share HPA axis-related effects with either TCAs or MAOIs. To test this hypothesis, we measured HPA axis-relevant gene expression in male C57BL/6 mice treated for 5 weeks with 10 mg/kg/day fluoxetine. To control for potential fluoxetine-induced changes in glucocorticoid secretion, mice were adrenalectomized and given fixed levels of glucocorticoids. Fluoxetine decreased glucocorticoid receptor (GR) gene expression in the prefrontal cortex, amygdala, locus coeruleus and dorsal raphé nucleus, and increased locus coeruleus tyrosine hydroxylase and dorsal raphé nucleus tryptophan hydroxylase-2 (TPH2) gene expression.

The TEER was calculated from the resistance using Eqn.(1), where the background resistance was 14 Ω and the membrane area was 1.54 cm2. The change in TEER for each insert was calculated using Eqn.(2). Treatments were compared in genstat (version 11) using residual maximum likelihood (REML) analysis with an unstructured covariance model to take into account the repeated measures. (1) Bacterial cultures were grown overnight in MRS broth at 37 °C with 5% CO2. Each culture was vortexed, and separate 10-mL aliquots were collected by centrifugation (3800 g for 20 min). Cell pellets were suspended to

an approximate cell concentration of 108–1010 CFU mL−1 in the following test solutions: MRS broth control, MRS broth adjusted to pH 2.0, MRS broth adjusted to pH 4.0, 0.5% w/v bile and 1% w/v bile. The time points (2 and 4 h) were chosen to represent the time it takes to pass through the human upper see more gastrointestinal system to the lower intestinal tract. The concentrations of bile (0.5% and 1%) and pH values (pH 2.0 and 4.0) were chosen to represent the range of these variables found in the human stomach. Bacterial viability was assessed after 2 and 4 h with triplicate 20-μL dilution spots on Z-VAD-FMK datasheet Luria–Bertani

(LB) agar plates. Values were log-transformed before REML analysis using an unstructured covariance model. Quantitative analysis of bacterial adherence to both confluent undifferentiated (5 days) and differentiated (18 days) Caco-2 cells was tested as described previously (Donnenberg & Nataro, 1995). Bacterial strains were grown overnight in MRS broth and approximately 107 CFU (10 μL) were added to each well, with each strain being assessed for Exoribonuclease adherence (3 and 6 h) in triplicate. Lactobacilli were enumerated on LB agar plates as described previously. Values were log-transformed

before anova analysis. The effect of coculture of L. plantarum DSM 2648 and EPEC O127:H6 (E2348/69) was examined in both the TEER and the cell adherence assay. The TEER assay was performed with two hourly readings for 10 h as described previously with overnight cultures of L. plantarum DSM 2648 prepared from MRS broths. The EPEC strain was grown aerobically overnight at 37 °C in LB broth, with shaking at 100 r.p.m. EPEC cells were collected by centrifugation (20 000 g for 5 min) and suspended in M199 with 1% v/v nonessential amino acids to an OD600 nm of 0.1. TEER coculture experiments also included both bacterial strains individually to assess separate effects for control purposes. For adherence to Caco-2 cell monolayers, both the L. plantarum DSM 2648 and the EPEC strain were grown in MRS and LB broth and inoculated into tissue culture wells containing undifferentiated Caco-2 cells as described previously. The EPEC strain was incubated alone or simultaneously cocultured with L. plantarum DSM 2648 for 3 or 6 h. The effects of a 3-h preincubation of L.

Forward [f] and reverse [r] primer pairs: CB58 [f] and CB57 [r] (icmW–CBU1651–icmX), CB59 [f] and CB60 [r] (icmV–dotA), CB718 [f] and CB716 [r] (dotA–CBU1647), CB603 [f] and CB602 [r] (dotB–CBU1646), selleck compound CB63 [f] and CB64 [r] (dotD–dotC–dotB), and CB62 [f] and CB61 [r] (icmT–icmS–dotD), were used to demonstrate transcriptional linkage. RT-PCR analysis of icmT, icmV, and icmW ORFs was performed using CB78 [f] and CB79 [r], CB70 [f] and CB71 [r], and CB40 [f] and CB41 [r], respectively. Oligonucleotide primers

(Table 1) for RT-qPCR analysis of icmX, icmW, icmV, dotA, dotB, and icmT were designed using primer3plus (Andreas Untergasser et al., 2007). The primer efficiency of all primer sets were within the efficiency window for the calculation method (Livak & Schmittgen, 2001; Schmittgen & Livak, 2008). Single-step RT-qPCR analysis using SuperScript III (Invitrogen) reverse transcriptase and the SYBR Green Master Mix Kit (Applied Biosystems) was performed on an ABI 7500 cycler. Each reaction contained 15 μL total volume and 20 ng total RNA. To calculate the relative temporal RNA

expression fold changes over the time course, to each individual gene was used, respectively. For each gene, the respective mean time-zero cycle threshold (CT) value was used as LDK378 the baseline reference point for all other (respective) mean time point CT values over the evaluation period. Therefore, for each individual gene, their relative fold expression at each time point is internally referenced to time zero RNA levels. Each time-zero point

has been referenced to themselves, resulting in a calculated fold value of 1. Statistical significance between the time points was evaluated by single-factor anova with a 95% confidence interval using ms excel 2007 (Microsoft). A P-value of <0.05 was considered significant. Recombinant C. burnetii IcmT  and protein-specific antibody were the same as described previously (Morgan et al., 2010). Briefly, to ensure specificity, the rabbit sera against recombinant C. burnetii IcmT were absorbed against Vero cell lysates as well as the Escherichia coli DH5α expression strain to remove cross-reactive antibodies. This antibody was designated RαIcmT. For immunoblot analysis, purified C. burnetii NMII was pelleted and resuspended in protein lysis/running buffer [Tris-HCl, pH 6.8, 62.5 mM, very sodium dodecyl sulfate (SDS) 2%, glycerol 25%, bromophenol blue 0.01%, and 2-mercaptoethanol 5% added before loading]. Protein representing 108C. burnetii genome equivalents and 104 Vero cells, respectively, was separated by 16% SDS-polyacrylamide gel electrophoresis and transferred to a nitrocellulose membrane (Whatman, Dassel, Germany) along with a protein ladder (Bio-Rad, Hercules, CA). Immunoblot analysis was carried out using a Pico Western Chemilluominescent Kit (Pierce, Rockford, IL) following the manufacturer’s directions using the RαIcmT primary antibody at a 1 : 1000 dilution in a hybridization buffer.

However, it remains possible that KS may impart an independent NVP-BKM120 cell line risk of mortality, as 91% of KS-related mortality occurred in the group with disseminated disease, similar to mortality rates observed in other studies [13-16]. Other studies have noted that improved immunological and virological responses are associated with clinical responses to KS [15]. However, our observation that the median CD4 count at the time of diagnosis for the patients with incident KS was 158 cells/μL compared with 83 cells/μL at baseline implies that

the risk for developing KS continues for some time, even with some degree of immune recovery. Other studies have shown the impact of HAART on KS in HIV-infected patients [17-19]. However, we had the opportunity to examine both risk factors for KS and clinical outcomes among patients predominantly treated with NNRTI-based regimens in a KS endemic country. The fact that regression rates in our study

are similar to those published for industrialized countries, learn more where clinical responses range from 67 to 85% [8, 9], should be somewhat reassuring to patients and physicians who do not have easy access to specific anti-neoplastic therapy or PI-based HAART regimens. Less than half of the patients in this study were able to access any chemotherapy for KS, and only four completed a full course of treatment, which suggests that NNRTI-based HAART may be adequate therapy for most patients who develop PAK6 KS when starting or while receiving HAART. Nevertheless, our study has a number of limitations. Because of the relatively small number of KS patients, we may have lacked sufficient power to detect other risk factors for

KS. This also limited our ability to ascertain differential response rates to different HAART regimens. In many instances we found factors that had ORs or HRs much greater than or less than 1, but with very wide confidence intervals. In particular, we had very few individuals who were switched from NNRTI-based regimens to PI-based regimens, which greatly limited our ability to detect differences in outcomes associated with these regimen changes. Furthermore, subjects were not randomly assigned to switch treatment and the lack of a significant difference in outcomes associated with treatment switching may have been attributable to other confounding factors. However, despite these limitations, these results are somewhat reassuring to patients and clinicians who may not have access to more expensive specific anti-neoplastic KS treatment or PI-based regimens. In conclusion, the use of NNRTI-based HAART regimens appears to induce remission of KS in HIV-infected patients in Uganda, although mortality associated with KS was still very high.

Striatal tissue from the adult rat was immunolabelled to reveal tyrosine hydroxylase (TH; biosynthetic enzyme of dopamine) and one of the three known VGluTs. Importantly, we compared the immunogold labelling for each of the VGluTs associated with TH-positive structures

with background labelling at the Ivacaftor in vitro electron microscopic level. In addition, we carried out a subregional analysis of the core and shell of the nucleus accumbens. We found that dopaminergic axons and terminals in the dorsolateral striatum and ventral striatum (nucleus accumbens core and shell) do not express VGluT1, VGluT2 or VGluT3. We conclude, therefore, that in the normal, adult rat striatum, dopaminergic axons do not co-release glutamate. “
“Intense feeding can be elicited by injections of the GABAA receptor antagonist bicuculline into the medial ventral pallidum (VPm), a basal forebrain structure anatomically interposed between two other feeding-related brain regions, the nucleus accumbens shell and the lateral hypothalamus (LH). To determine whether the VPm effects changes in feeding behavior through actions on the LH, we examined feeding following unilateral injections of bicuculline into the VPm made either ipsilateral or contralateral to a unilateral excitotoxic lesion of the LH in nondeprived rats. BIBW2992 We found

that lesions of the LH significantly attenuated feeding induced from the ipsilateral VPm, as compared to sham-operated controls. In striking contrast, unilateral LH lesions significantly potentiated the feeding response elicited by injections of bicuculline into the contralateral

VPm. The ‘ipsilateral–contralateral disruption’ design we used makes it extremely unlikely that our findings could have resulted from nonspecific effects of the lesions. These results suggest that the LH is causally involved in mediating the ingestive effects produced by activation of the VPm, and provide an important insight mafosfamide into the functional circuitry by which basal forebrain structures control food intake in mammals. “
“The throughput of information from the accessory olfactory bulb (AOB) to downstream structures is controlled by reciprocal dendrodendritic inhibition of mitral cells by granule cells. Given the high expression levels of mGluR2, a metabotropic glutamate receptor, in the AOB and the fact that the activation of mGluR2 permits the formation of a specific olfactory memory, we reasoned that mGluR2 might play an important role in regulating dendrodendritic inhibition. To test this hypothesis, we examined the effects of pharmacological and genetic manipulations of mGluR2 on synaptic responses measured from mitral or granule cells in slice preparations from 23- to 36-day-old Balb/c mice.

The MTCT rate decreased substantially after 1994, reaching 1% in 2005–2007 (Table 1). Among premature infants, the crude MTCT rates for those delivered by elective CS, by emergency CS and vaginally were 2.8% (nine of 319), 6.2% (14 of 226) and 21.6% (58 of 268), respectively; 79% (251 of 319) of those delivered by elective CS were born

at 35–36 weeks and for 96% Entinostat mw maternal HIV infection was stated as the CS indication. Elective CS and emergency CS delivery were both univariably associated with a statistically significant reduction in MTCT risk overall vs. vaginal delivery [respective ORs 0.06 (95% CI 0.02–0.16) and 0.19 (95% CI 0.09–0.42)]. In multivariable analysis adjusting for maternal CD4 cell count and receipt of antenatal ART (classified as none, mono/dual therapy and HAART), including 496 premature infants, elective CS was associated with an 89% decreased E7080 price risk of MTCT (AOR 0.11; 95% CI 0.03–0.32; P<0.001) and emergency CS with a 63% reduced risk (AOR 0.37; 95% CI 0.16–0.87; P=0.02). Repeating this analysis for the 2081 MCPs with term delivery, elective CS was associated with a halving of MTCT risk (AOR 0.49; 95% CI 0.30–0.80; P=0.004), but the association with emergency CS was not significant (AOR 0.74; 95% CI 0.38–1.43; P=0.37). Results from a subanalysis among all MCPs with maternal viral load <400 copies/mL (n=960) are presented in Table 3. Elective CS and emergency CS were associated with a reduced MTCT risk

vs. vaginal delivery, but the emergency CS association was only of borderline significance. We were unable to repeat this analysis restricted to the 559 MCPs with maternal viral load <50 copies/mL,

as there were only two cases of vertical transmission (overall MTCT rate 0.4%; 95% CI 0.04–1.29): one infected infant was born vaginally at <34 weeks and the other by elective CS at 37 weeks; both mothers were receiving HAART in pregnancy, the former from before pregnancy and the latter for 2 months prior to delivery. A further analysis was performed to explore the value of a strategy of an elective CS (prophylactic CS) to prevent MTCT vs. a policy of vaginal delivery (including vaginal deliveries converted to an emergency CS) in women on HAART. Among 1132 Phosphoprotein phosphatase women on HAART with viral load measurements available 30 days before delivery or 1 day post-partum, the MTCT rate was 0.65% (two of 310) among women who started their labour vaginally (both transmissions occurred among women with viral loads ≥1000 copies/mL) and 1.3% (11 of 822) among those who had a prophylactic CS (P=0.64); among the subgroup of women with viral load <1000 copies/mL, three of those having a prophylactic CS transmitted (0.7%; three of 424; 95% CI 0.15–2.05) and none of those who started their labour vaginally did so (0 of 155; one-sided 97.5% CI 2.35%). The MTCT rate among women undergoing prophylactic CS with HIV RNA levels <50 copies/mL was 0.4% (1 of 238) (P=0.48).

The study protocol was approved by the ethics committee of the Hospital Clinic of Barcelona. On June 19, 2009, the medical students traveled from Barcelona to Santo Domingo, Dominican Republic on a scheduled flight with a stopover in Madrid. A bus took them to their hotel located at a beach resort in Punta Cana. Meals were shared depending on daily activities organized and the number of students participating in each activity. The students slept in rooms for two, three,

or four Dabrafenib nmr people with members of their own travel group. Activities were organized according to the interests of the students, and included sightseeing excursions. On June 26, all students traveled on the same bus on a 4-hour trip from Punta Cana to Santo Domingo, where they boarded an Airbus aircraft with 284 economy class and 20 business class seats. The flight back

to Spain lasted 8 hours. Of the 113 students, 86 (76%) were contacted and agreed to participate in the study. The rest could not be contacted or declined to participate. Of the 86 students, 58 (67%) were female. The median age was 24 years, (range 22–56 y). A total of 62 (72%) students developed ILI, and influenza A(H1N1) was confirmed in 39 (45%) (two confirmed cases GSK2126458 were asymptomatic). Thus, assuming that none of the students who did not participate were ill or infected, the minimum attack rate among all 113 students was 55% for probable influenza and 35% for confirmed influenza. Two of the 37 confirmed cases developed symptoms during the stay in the Dominican Republic. The

first confirmed case first developed symptoms on June 24, followed by a second case on June 25 (2 and 1 d before starting the return trip, respectively). Between June 26 (day of departure ADAMTS5 from Santo Domingo) and 48 hours after arriving in Barcelona, 29/39 (74%) of the students with confirmed A(H1N1) infection developed symptoms; 6 students (15%) developed symptoms more than 72 hours later, and 2 remained asymptomatic (Figure 1). The predominant symptoms in confirmed cases (Table 1) were cough (87%), malaise (60%), and sore throat (51%). Gastrointestinal symptoms (diarrhea) were reported by 16 (43%) of the confirmed cases. Univariate analyses showed that cough, fever, myalgia, rhinorrhea, and malaise were significantly associated with confirmed infections, and this was supported by the logistic regression analysis (Table 1). Laboratory testing for influenza was more likely to be negative when the time between the onset of illness and the day of diagnostic sampling was longer (Figure 2). The mean time between onset of symptoms and blood sampling was 3.5 days; most (92%) of the positive samples were obtained between 1 and 3 days after onset, whereas most (83%) of the negative samples were obtained 3 or more days after onset. On arriving home from the trip, the students went to their homes, where they lived with family or other students.