HIV incidence in the Estonian population in 2013 determined using the HIV-1 limiting antigen avidity assay.

OBJECTIVES: Estonia has one the highest number of new HIV diagnoses in the European Union, mainly among injecting drug users and heterosexuals. Little is known of HIV incidence, which is crucial for limiting the epidemic. Using a recent HIV infection testing algorithm (RITA) assay, we aimed to estimate HIV incidence in 2013. METHODS: All individuals aged ≥18 years newly-diagnosed with HIV in Estonia January- December 2013, except blood donors and those undergoing antenatal screening, were included. Demographic and clinical data were obtained from the Estonian Health Board and the Estonian HIV-positive patient database. Serum samples were tested for recent infection using the LAg-avidity EIA assay. HIV incidence was estimated based on previously published methods. RESULTS: Of 69,115 tested subjects, 286 (0.41%) were newly-diagnosed with HIV with median age of 33 years (IQR: 28-42) and 65% male. Self-reported routes of HIV transmission were mostly heterosexual contact (n = 157, 53%) and injecting drug use (n = 62, 21%); 64 (22%) were with unknown risk group. Eighty two (36%) were assigned recent, resulting in estimated HIV incidence of 0.06%, corresponding to 642 new infections in 2013 among the non-screened population. Incidence was highest (1.48%) among people who inject drugs. CONCLUSIONS: These high HIV incidence estimates in Estonia call for urgent action of renewed targeted public health promotion and HIV testing campaigns.

EAN consensus review on prevention, diagnosis and management of tick-borne encephalitis.

BACKGROUND AND PURPOSE: Tick-borne encephalitis (TBE) is an infection of the central nervous system (CNS) caused by tick-borne encephalitis virus (TBEV) and transmitted by ticks, with a variety of clinical manifestations. The incidence of TBE in Europe is increasing due to an extended season of the infection and the enlargement of endemic areas. Our objectives are to provide recommendations on the prevention, diagnosis and management of TBE, based on evidence or consensus decisions. METHODS: For systematic evaluation, the literature was searched from 1970 to 2015 (including early online publications of 2016), and recommendations were based on evidence or consensus decisions of the Task Force when evidence-based data were not available. RECOMMENDATIONS: Vaccination against TBE is recommended for all age groups above 1 year in highly endemic areas (≥5 cases/100 000/year), but also for individuals at risk in areas with a lower incidence. Travellers to endemic areas should be vaccinated if their visits will include extensive outdoor activities. Post-exposure prophylaxis after a tick bite is not recommended. A case of TBE is defined by the presence of clinical signs of meningitis, meningoencephalitis or meningoencephalomyelitis with cerebrospinal fluid (CSF) pleocytosis (>5 × 106 cells/l) and the presence of specific TBEV serum immunoglobulin M (IgM) and IgG antibodies, CSF IgM antibodies or TBEV IgG seroconversion. TBEV-specific polymerase chain reaction in blood is diagnostic in the first viremic phase but it is not sensitive in the second phase of TBE with clinical manifestations of CNS inflammation. Lumbar puncture should be performed in all patients with suspected CNS infection unless there are contraindications. Imaging of the brain and spinal cord has a low sensitivity and a low specificity, but it is useful for differential diagnosis. No effective antiviral or immunomodulating therapy is available for TBE; therefore the treatment is symptomatic. Patients with a potentially life threatening meningoencephalitis or meningoencephalomyelitis should be admitted to an intensive care unit. In the case of brain oedema, analgosedation should be deepened; osmotherapy and corticosteroids are not routinely recommended. If intracranial pressure is increased, therapeutic hypothermia or decompressive craniectomy might be considered. Seizures should be treated as any other symptomatic epileptic seizures. CONCLUSIONS: Tick-borne encephalitis is a viral CNS infection that may result in long-term neurological sequelae. Since its incidence in Europe is increasing due to broadening of endemic areas and prolongation of the tick activity season, the health burden of TBE is enlarging. There is no effective antiviral treatment for TBE, but the disease may be effectively prevented by vaccination.

An observational study of blood concentrations and kinetics of methyl- and propyl-parabens in neonates.

PURPOSE: Systemic exposure to parabens in the neonatal population, in particular propyl-parabens (PPB), remains a concern. Blood concentrations and kinetics of methyl-parabens (MPB) and PPB were therefore determined in neonates receiving medicines containing these excipients. METHODS: A multi-centre, non-interventional, observational study of excipient-kinetics in neonates. 'Dried Blood Spot' samples were collected opportunistically at the same time as routine samples and the observations modelled using a non-linear mixed effects approach. RESULTS: A total of 841 blood MPB and PPB concentration data were available for evaluation from 181 pre- and term-neonates. Quantifiable blood concentrations of MPB and PPB were observed in 99% and 49% of patients, and 55% and 25% of all concentrations were above limit of detection (10 ng/ml), respectively. Only MPB data was amenable to modelling. Oral bioavailability was influenced by type of formulation and disposition was best described by a two compartment model with clearance (CL) influenced by post natal age (PNA); CL PNA<21 days 0.57 versus CL PNA>21 days 0.88 L/h. CONCLUSIONS: Daily repeated administration of parabens containing medicines can result in prolonged systemic exposure to the parent compound in neonates. Animal toxicology studies of PPB that specifically address the neonatal period are required before a permitted daily exposure for this age group can be established.

Impact of empiric antibiotic regimen on bowel colonization in neonates with suspected early onset sepsis.

The purpose of this study was to compare the impact of ampicillin and penicillin used for empiric treatment of early onset sepsis (EOS) on initial gut colonization by aerobic and facultative anaerobic microorganisms. A cluster-randomized, two-center, switch-over study was conducted in two paediatric intensive care units in Estonia and included 276 neonates. Rectal swabs were collected twice a week until discharge or day 60. Colonizing microbes were identified on species level and tested for ampicillin resistance (AR). The number of patients colonized with Gram negative microorganisms and Candida spp was similar in both treatment arms but ampicillin resulted in longer colonization duration (CD) of K. pneumonia (p = 0.012), AR Serratia spp (p = 0.012) and Candida spp (p = 0.02) and penicillin in that of AR Acinetobacter spp (p = 0.001). As for Gram positive microorganisms penicillin treatment was associated with a greater number of colonized patients and higher CD of Enterococcus spp and S. aureus but lower ones of S. haemolyticus and S. hominis. Influence of ampicillin and penicillin on initial gut colonization is somewhat different but these differences are of low clinical relevance and should not be a limiting step when choosing between these two antibiotics for the empiric treatment of EOS.

Comparison of ampicillin plus gentamicin vs. penicillin plus gentamicin in empiric treatment of neonates at risk of early onset sepsis.

AIM: We aimed to compare the clinical efficacy of ampicillin (AMP) vs. penicillin (PEN) both combined with gentamicin in the empirical treatment of neonates at risk of early onset neonatal sepsis (EOS). METHODS: We performed an open label cluster randomized equivalence study in both Estonian neonatal intensive care units, including neonates with suspected EOS, aged less than 72 h. Primary end-point was clinical failure rate, expressed by need for change of antibiotic regimen within 72 h and/or 7-day all cause mortality. Bowel colonization was followed with biweekly perineal swab cultures. RESULTS: Incidence of proven EOS was 4.9%. Among neonates receiving AMP (n = 142) or PEN (n = 141) change of antibiotic regimen within 72 h (10/142 vs. 10/141; OR 1.02; 95% CI 0.40-2.59), 7-day mortality (11/142 vs. 14/141; OR 0.76; 95% CI 0.33-1.75) and over-all treatment failure (20/142 vs. 20/141; OR 1.01; 95% CI 0.52-1.97) occurred at similar rates. The only differences in gut colonization were lower number of patients colonised with enterococci, S. aureus and AMP resistant Acinetobacter spp. in AMP and lower number of those with S. haemolyticus and S. hominis in PEN arm. CONCLUSIONS: AMP and PEN combined with gentamicin have similar effectiveness in the empiric treatment of suspected neonatal EOS.

Antimicrobial susceptibility and serogroup/serotype distribution of nasopharyngeal isolates of Streptococcus pneumoniae in healthy Estonian children in 1999-2003.

This study determined nasopharyngeal (NP) carriage rates of Streptococcus pneumoniae among healthy Estonian children, aged 1-7 years, and characterised the serotype/serogroup distribution and antibiotic susceptibility rates. NP swabs were collected from 685 previously healthy children attending 29 day care centres during the winters of 1999-2000 and 2003. The NP carriage rate of S. pneumoniae was 44%. Rates of penicillin and erythromycin non-susceptibility were low (both 6%), but high (67%) rates of co-trimoxazole resistance were found. Among the pneumococcal serotypes identified, 64% were included in or cross-reacted with the licensed heptavalent pneumococcal vaccine.

Pharmacokinetics and pharmacodynamics of cephalosporins in cerebrospinal fluid.

Largely because of their low lipophilicity, cephalosporins poorly penetrate through the blood-brain barrier, achieving relatively low cerebrospinal fluid (CSF) concentrations. However, the minimum bactericidal concentrations (MBCs) of the extended spectrum cephalosporins for common meningeal pathogens are generally low; thus, therapeutic CSF drug concentrations several-fold greater than the MBC can be achieved with currently recommended dosage regimens. However, the effectiveness of cephalosporin therapy is unreliable in patients with meningitis caused by highly penicillin-resistant pneumococci. As in other body sites, the bactericidal activity of cephalosporins in CSF predominantly depends on the time their concentrations exceed the MBC of infecting organisms (t>MBC). Experimental studies show that, for maximal efficacy, t>MBC values greater than 90% of the dosage interval are required in meningitis. Such values are usually achieved in humans with currently recommended dosage regimens because the half-lives of cephalosporins are 2- to 3-fold longer in CSF than in serum. Several advanced generation cephalosporins have shown equal efficacy in clinical trials, but only cefotaxime, ceftriaxone and ceftazidime are currently approved for the treatment of patients with bacterial meningitis.

Buffy coat PCR for diagnosis of experimental pneumococcal pneumonia.

An immunocompetent murine model of pneumococcal pneumonia and bacteremia was used to evaluate a PCR assay based on amplification of the pneumolysin gene. Mice were treated with trovafloxacin to determine the decline in sensitivity of PCR as lung bacterial concentrations decreased and blood cultures became sterile. Forty-three mice were studied for up to 120 h after start of antibiotic treatment. PCR of buffy coat specimens was more sensitive than PCR of plasma. Only 21% of animals had a positive blood culture, whereas 77% of PCR buffy coat assays were positive. After 48 h of therapy all blood culture specimens were sterile, whereas buffy coat PCR was positive in 57.8% of specimens. PCR of buffy coat specimens was negative in all mice colonized nasally with Streptococcus pneumoniae and in rabbits with Escherichia coli bacteremia. Our results demonstrate that our PCR technique using buffy coat specimens is highly specific for invasive pneumococcal disease and remains positive in the majority of animals for at least 48 h after start of antibiotic therapy.

Five-year prospective surveillance of nosocomial bloodstream infections in an Estonian paediatric intensive care unit.

BACKGROUND: Few studies provide rates of nosocomial bloodstream infections (BSIs) in mixed neonatal and paediatric intensive care units (PICUs). AIM: To determine the rate, pathogens and outcome of BSIs in an Estonian PICU. METHODS: Data were collected prospectively from 1st January 2004 to 31st December 2008 in the PICU of Tartu University Hospital. The definition criteria of the US Centers for Disease Control and Prevention were applied for the diagnosis of laboratory-confirmed BSI. FINDINGS: A total of 126 episodes of BSI were identified in 89 patients (74 neonates, eight infants, seven patients aged >1 year). Among neonates 42 (57%) had birth weight <1000 g. The overall incidence of BSI was 9.2 per 100 admissions, incidence density 12.8 per 1000 patient-days. Primary BSI was diagnosed in 92 episodes. Central line (CL)-associated BSI incidence density for neonates was 8.6 per 1000 CL-days with the highest incidence (27.4) among neonates with extremely low birth weight. The most common pathogens were coagulase-negative staphylococci (43%) and Serratia marcescens (14%). Resistance to meticillin was detected in four out of seven S. aureus isolates (all were part of an outbreak) and 23% of Enterobacteriaceae were extended spectrum beta-lactamase (ESBL)-producing strains. Overall case-fatality rate was 10%. CONCLUSION: We observed higher rates of BSIs in our mixed PICU than reported previously. High levels of antimicrobial resistance were detected. Future research should focus on the effects of infection control measures to prevent outbreaks and to decrease incidence of CL-associated BSI.

Risk assessment of neonatal excipient exposure: lessons from food safety and other areas.

Newborn babies can require significant amounts of medication containing excipients intended to improve the drug formulation. Most medicines given to neonates have been developed for adults or older children and contain excipients thought to be safe in these age groups. Many excipients have been used widely in neonates without obvious adverse effects. Some excipients may be toxic in high amounts in which case they need careful risk assessment. Alternatively, it is conceivable that ill-founded fears about excipients mean that potentially useful medicines are not made available to newborn babies. Choices about excipient exposure can occur at several stages throughout the lifecycle of a medicine, from product development through to clinical use. Making these choices requires a scalable approach to analysing the overall risk. In this contribution we examine these issues.

Mucosal surveillance cultures in predicting Gram-negative late-onset sepsis in neonatal intensive care units.

This study aimed to examine the spectrum and time course of gut and nasopharyngeal colonization with Gram-negative micro-organisms, and to define the value of surveillance cultures in predicting late-onset sepsis in neonates admitted to neonatal intensive care units. Nasopharyngeal and rectal swabs were collected on admission and twice weekly thereafter in 278 neonates admitted within the first 72 h of life with risk factors of early-onset sepsis. Sterile body fluid cultures were obtained on admission and subsequently as clinically indicated. Approximately half of the rectal (693/1250, 55%) and nasopharyngeal (558/1153, 48%) samples but only 6% (32/555) of the sterile fluid samples in 26 patients were culture positive for Gram-negative organisms. In total, 2108 invasive and mucosal culture pairs were analysed. The overall sensitivity, specificity, and positive and negative predictive values of a mucosal sample to predict late-onset sepsis were 27%, 66%, 4% and 94%, respectively. Patients with pre-existing colonization with Klebsiella pneumoniae (P = 0.011), Klebsiella oxytoca (P = 0.002), Escherichia coli (P = 0.003), Stenotrophomonas spp. (P = 0.003) and Pseudomonas spp. (P ≤ 0.001) were more likely to develop late-onset sepsis. No such association was found for Acinetobacter baumannii, Serratia spp. or Enterobacter cloacae. In conclusion, routine mucosal cultures are inefficient for the prediction of Gram-negative late-onset sepsis in neonatal intensive care units. However, targeted screening for specific organisms in an outbreak (e.g. Klebsiella spp., E. coli, Stenotrophomonas spp. and Pseudomonas spp.) may offer an opportunity to improve infection control measures and enable timely initiation of appropriate antibiotic therapy.

Immunogenicity and safety of a combined hepatitis A and B vaccine administered concomitantly with either a measles-mumps-rubella or a diphtheria-tetanus-acellular pertussis-inactivated poliomyelitis vaccine mixed with a Haemophilus influenzae type b conjugate vaccine in infants aged 12-18 months.

Two studies were undertaken to investigate the concomitant administration of combined hepatitis A/B vaccine with a diphtheria-tetanus-acellular pertussis-inactivated poliomyelitis vaccine mixed with Haemophilus influenzae vaccine (DTPa-IPV/Hib), or with a measles-mumps-rubella vaccine (MMR), during the second year of life. On completion of the vaccination course, all subjects were seropositive or seroprotected against all antigens except for one subject who was seronegative for anti-PT. Seropositivity and seroprotection rates for all other antibodies were comparable to reference values for each vaccine component, indicating that the immunogenicity of MMR, DTPa-IPV/Hib and combined hepatitis A/B vaccines is not impaired by co-administration. All vaccines were well tolerated.

New antibiotics.

Three broad-spectrum antibiotics are reviewed, each from a different class. Meropenem is closely related to imipenem and was recently approved for use in children. Its advantages over imipenem include greater activity against gram-negative bacteria and lack of association with seizures. Cefepime is a fourth generation cephalosporin with the gram-positive activity of cefotaxime and the gram-negative spectrum of ceftazidime. Trovafloxacin is a fluoroquinolone with an exceptionally broad antibacterial spectrum. Meropenem is approved for use in children, cefepime is approved for use in adults only, and trovafloxacin is still undergoing clinical trials. These agents should be reserved for treatment of serious infections, especially those in immunocompromised patients or polymicrobial infections.

Antibiotic pharmacodynamics in cerebrospinal fluid.

The CSF half-lives of lipophilic agents, such as quinolones, are similar to those in serum and peak concentrations in CSF are achieved relatively quickly. In contrast, the pharmacokinetics of hydrophilic agents (beta-lactams and vancomycin) in CSF often differ from those in serum. In particular, the half-lives of these agents in CSF tend to be extended, and the time to achieve peak concentrations in CSF is delayed. Hydrophilic antibiotics, such as beta-lactams, penetrate poorly through the BBB, but CSF penetration is significantly increased in the presence of inflammation. In contrast, lipophilic antibiotics, such as quinolones, enter the CSF more efficiently and their penetration is not inflammation dependent. The pharmacodynamic properties of antibiotics in CSF are generally similar to those in other body sites; beta-lactam agents and vancomycin are time-dependent, whereas the quinolones and aminoglycosides are concentration-dependent. However, a notable difference from infections in other sites is that quinolones have a short PAE in CSF and need to continually exceed the MBC for maximal effectiveness. Thus, in CSF, quinolones demonstrate features of both concentration-dependency and time-dependency, evidence that the AUC/MBC is an important predictor of effectiveness. With the exception of quinolones, many antibiotics appear to have prolonged sub-MIC effects and longer half-lives in CSF than in serum, suggesting that dosing intervals longer than those used traditionally would be effective in meningitis. However, this requires clinical verification.

Enzymatic changes in the cerebrospinal fluid in patients with infections of the central nervous system.

Enzymatic determinations in cerebrospinal fluid (CSF) of aspartate aminotransferase (AST), lactic dehydrogenase (LDH), gammaglutamyl transpeptidase (GGT), creatine phosphokinase (CPK) and creatine kinase BB (CK-BB) were performed in 16 patients with aseptic meningitis (AM), in 25 children with bacterial meningitis (BM) and in 15 patients with meningism. The activity of AST and GGT was significantly higher in patients with BM on admission compared with those with AM and meningism (p < 0.05 and p < 0.005, respectively) and decreased with therapy. The highest concentration of AST and LDH appeared in patients with poor outcome as well as in those with ventriculomegaly on neurosonography (p < 0.05). The concentration of CK-BB increased in all patient groups on admission and remained higher on termination of therapy. The present study confirms the high activity of AST and GGT in BM patients in the CSF whereas the increased activity of AST and LDH reflects the extent of brain injury. Nevertheless, the prognosis for individual patients cannot be established on the basis of enzyme activity alone, but depends on several factors.

Safety and immunogenicity of combined Dtpa-IPV vaccine for primary and booster vaccination.

This study evaluated the safety and immunogenicity of combined diphtheria, tetanus, acellular pertussis, inactivated poliomyelitis vaccine (DTPa-IPV) given as primary immunization at ages 3, 4.5 and 6 months and a booster dose between the ages of 18 and 27 months to healthy children. The acellular pertussis tricomponent vaccine contains pertussis toxoid (PT), filamentous haemaglutinin (FHA) and 69 kDa outer membrane protein (PRN). Serum immune responses to the administered antigens were measured before and after the primary and the booster vaccination series. The safety of the vaccine was evaluated based on diary cards completed by parents within 4 d following each vaccination. A total of 237 and 150 children completed the primary and booster vaccination series, respectively. A total of 483 (66.5%) and 111 (74%) local and 317 (43.7%) and 98 (65.3%) general adverse events were reported after 726 doses of the primary series and 150 of the booster doses, respectively. Compared with primary vaccination, the incidence of all adverse symptoms was greater after the booster dose and a previous severe reaction was a risk factor for a severe reaction after the booster dose (OR = 5.11). All but 1 child, who failed to have antibodies to diphtheria toxoid after the booster dose, responded to all administered antigens with antibody titres greater than the assay cut-off points. The combined DTPa-IPV used for primary and booster immunization induced good immunity, but was associated with large local reactions in 21.3% of children after the booster dose.

Pharmacodynamics and bactericidal activity of ceftriaxone therapy in experimental cephalosporin-resistant pneumococcal meningitis.

Adequate concentrations of beta-lactam antibiotics in cerebrospinal fluid (CSF) are difficult to achieve for meningitis caused by drug-resistant Streptococcus pneumoniae. Ceftriaxone in dosages of 150 or 400 mg/kg of body weight per day, given in one or two doses, was used for the treatment of experimental highly cephalosporin-resistant (MIC and MBC, 4 microg/ml) pneumococcal meningitis. The bacterial killing rate (delta log10 CFU per milliliter per hour) and pharmacokinetic indices, including percentage of time the antibiotic concentration exceeded the MBC during a 24-h period (T>MBC), CSF peak concentration above the MBC, and area under the concentration-time curve from 0 to 24 h above MBC, were measured and correlated. By multiple stepwise regression, only T>MBC independently predicted the bacterial killing rate. There was a direct linear correlation between T>MBC in CSF and the bacterial killing rate during the first 24 h of therapy (r = 0.87; P = 0.004). Sterilization of CSF was achieved only when the T>MBC was 95 to 100%. In the first 24 h, the 200-mg/kg/12-h regimen, compared with the 400-mg/kg/24-h regimen, was associated with a greater T>MBC (87% +/- 10% versus 60% +/- 22%; P = 0.03) and greater bacterial killing rate (0.2 +/- 0.04 versus 0.13 +/- 0.07; P = 0.003), confirming that ceftriaxone exhibits time-dependent bactericidal activity. After 24 h, the T>MBC and the CSF sterilization rates were similar whether ceftriaxone was given once or twice daily.

Five days of antibacterial therapy for bacterial meningitis in children?

We evaluated the effectiveness of 5-day antibacterial therapy for bacterial meningitis in children. The study group included 26 children from 2 months to 15 years of age, admitted with microbiologically confirmed bacterial meningitis in 1990-1993 and treated for 5 days. A historical comparison group of 49 patients treated for 8 to 15 days was used. Penicillin monotherapy (300 mg/kg body weight) was used for meningococcal and pneumococcal meningitis and ampicillin (300 mg/kg body weight) for Haemophilus influenzae b meningitis. On day 5 of therapy the activity of aspartate aminotransferase (AST), lactic dehydrogenase (LDH), creatine phosphokinase (CPK) and gamma-glutamyl-transpeptidase (gamma GT) in the CSF was determined by photocolorimetric assay and the concentration of creatine kinase BB (CK-BB) by ELISA. IL-6 was analysed using EIA technique and a cerebral ultrasound was performed at the time of the termination of the antibacterial therapy. The mean follow-up time was 1.3 years for children in the study group and 3.2 in the control group. The time of hospitalisation was shorter in children treated for 5 days (p < 0.005). Complete clinical recovery was 81% in the study group and 66% in the comparison group at the time of the termination of antibacterial therapy. No relapses occurred. The activity of AST, CPK, LDH, and gamma GT in the CSF had returned to normal by the 5th day of therapy, but almost a 7-fold higher concentration of CK-BB was registered. The concentration of IL-6 in the CSF decreased with the therapy from 1,800 pg/ml to 685 pg/ml but still remained high.(ABSTRACT TRUNCATED AT 250 WORDS)