Repercussions of the COVID-19 pandemic on child and adolescent mental health: A matter of concern-A joint statement from EAP and ECPCP

COVID-19 pandemic and the consequent rigid social distancing measures implemented, including school closures, have heavily impacted children's and adolescents' psychosocial wellbeing, and their mental health problems significantly increased. However, child and adolescent mental health were already a serious problem before the Pandemic all over the world. COVID-19 is not just a pandemic, it is a syndemic and mentally or socially disadvantaged children and adolescents are the most affected. Non-Communicable Diseases (NCDs) and previous mental health issues are an additional worsening condition. Even though many countries have responded with decisive efforts to scale-up mental health services, a more integrated and community-based approach to mental health is required. EAP and ECPCP makes recommendations to all the stakeholders to take action to promote, protect and care for the mental health of a generation.

No evidence of ongoing HIV replication or compartmentalization in tissues during combination antiretroviral therapy: Implications for HIV eradication

HIV persistence during combination antiretroviral therapy (cART) is the principal obstacle to cure. Mechanisms responsible for persistence remain uncertain; infections may be maintained by persistence and clonal expansion of infected cells or by ongoing replication in anatomic locations with poor antiretroviral penetration. These mechanisms require different strategies for eradication, and determining their contributions to HIV persistence is essential. We used phylogenetic approaches to investigate, at the DNA level, HIV populations in blood, lymphoid, and other infected tissues obtained at colonoscopy or autopsy in individuals who were on cART for 8 to 16 years. We found no evidence of ongoing replication or compartmentalization of HIV; we did detect clonal expansion of infected cells that were present before cART. Long-term persistence, and not ongoing replication, is primarily responsible for maintaining HIV. HIV-infected cells present when cART is initiated represent the only identifiable source of persistence and is the appropriate focus for eradication.

Identification and characterization of HIV positive Ethiopian elite controllers in both Africa and Israel

OBJECTIVES

HIV elite controllers (ECs) are a unique subgroup of HIV-positive patients who are long-term virologically suppressed in the absence of antiretroviral treatment (ART). The prevalence of this subgroup is estimated to be < 1%. Various cohorts of ECs have been described in developed countries, most of which have been demographically heterogeneous. The aim of this study was to identify ECs in two large African cohorts and to estimate their prevalence in a relatively genetically homogenous population.

METHODS

We screened two cohorts of HIV-positive Ethiopian patients. The first cohort resided in Mekelle, Ethiopia. The second was comprised of HIV-positive Ethiopian immigrants in Israel. In the Mekelle cohort, ART-naïve subjects with stable CD4 counts were prospectively screened using two measurements of viral load 6 months apart. Subjects were defined as ECs when both measurements were undetectable. In the Israeli cohort, subjects with consistently undetectable viral loads (mean of 17 viral load measurements/patient) and stable CD4 count > 500 cells/μL were defined as ECs.

RESULTS

In the Mekelle cohort, 16 of 9515 patients (0.16%) fitted the definition of EC, whereas seven of 1160 (0.6%) in the Israeli cohort were identified as ECs (P = 0.011).

CONCLUSIONS

This is the first large-scale screening for HIV-positive ECs to be performed in entirely African cohorts. The overall prevalence of ECs is within the range of that previously described in developing countries. The significant difference in prevalence between the two cohorts of similar genetic background is probably a consequence of selection bias but warrants further investigation into possible environmental factors which may underlie the EC state.

Migrant children's health problems, care needs, and inequalities: European primary care paediatricians' perspective

BACKGROUND

Primary care paediatricians' perception of migrant children's health in Europe has not been explored before. Our aim was to examine European paediatricians' knowledge on migrant children's health problems, needs, inequalities, and barriers to access health care.

METHODS

European primary care paediatricians were invited by the European Academy of Paediatrics Research in Ambulatory Setting Network country coordinators to complete a web-based survey concerning health care of migrant children. A descriptive analysis of all variables was performed.

RESULTS

The survey was completed by 492 paediatricians. Sixty-three per cent of the respondents reported that the general health of migrant children is worse than that of nonmigrants, chronic diseases cited by 66% of the respondents as the most frequent health problem. Sixty-six per cent of the paediatricians reported that migrant children have different health needs compared to nonmigrant children, proper oral health care mentioned by 86% of the respondents. Cultural/linguistic factors have been reported as the most frequent barrier (90%).to access health care. However, only 37% of providers have access to professional interpreters and cultural mediators. Fifty-two per cent and 32% do not know whether one or more of the family members are undocumented and whether they are refugees/asylum seekers, respectively. Updated guidelines for care of migrant children are available for only 35% of respondents, and 80% of them have not received specific training on migrant children's care.

CONCLUSIONS

European primary care paediatricians recognize migrant children as a population at risk with more frequent and specific health problems and needs, but they are often unaware of their legal state. Lack of interpreters augments the existing language barriers to access proper care and should be solved. Widespread lack of guidelines and specific providers' training should be addressed to optimize health care delivery to migrant children.

Use of electronic health records by child primary healthcare providers in Europe

BACKGROUND

There is limited data on the use and functionality level of electronic health records (EHRs) supporting primary child health care in Europe. Our objective was to determine European primary child healthcare providers' use of EHRs, and functionality level of the systems used.

METHODS

European primary care paediatricians, paediatric subspecialists and family doctors were invited by European Academy of Paediatrics Research in Ambulatory Setting Network (EAPRASnet) country coordinators to complete a web-based survey on the use of EHRs and the systems' functionalities. Binomial logistic analysis has been used to evaluate the effect of specialty and type of practice on the use of EHRs.

RESULTS

The survey was completed by 679 child primary healthcare providers (response rate 53%). Five hundred and fifty four responses coming from 10 predominant countries were taken for further analysis. EHR use by respondents varied widely between countries, all electronic type use ranging between 7% and 97%. There was no significant difference in EHR use between group practice and solo practitioners, or between family doctors and primary care paediatricians. History and physical examination can be properly recorded by respondents in most countries. However, growth chart plotting capacity in some countries ranges between 22% and 50%. Vaccination recording capacity varies between 50% and 100%, and data exchange capacity with immunization databases is mostly limited, ranging between 0% and 54%.

CONCLUSIONS

There is marked heterogeneity in the use and functionalities of EHRs used among child primary child healthcare providers in Europe. More importantly, lack of critical paediatric supportive functionalities like growth tracking and vaccination status has been documented in some countries. There is a need to explore the reasons for these findings, and to develop a cross European paediatric EHR standards.

Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

Efficacy of tenofovir and efavirenz in combination with lamivudine or emtricitabine in antiretroviral-naive patients in Europe

BACKGROUND

The combination of tenofovir and efavirenz with either lamivudine or emtricitabine (TELE) has proved to be highly effective in clinical trials for first-line treatment of HIV-1 infection. However, limited data are available on its efficacy in routine clinical practice.

METHODS

A multicentre cohort study was performed in therapy-naive patients initiating ART with TELE before July 2009. Efficacy was studied using ITT (missing or switch = failure) and on-treatment (OT) analyses. Genotypic susceptibility scores (GSSs) were determined using the Stanford HIVdb algorithm.

RESULTS

Efficacy analysis of 1608 patients showed virological suppression to <50 copies/mL at 48 weeks in 91.5% (OT) and 70.6% (ITT). Almost a quarter of all patients (22.9%) had discontinued TELE at week 48, mainly due to CNS toxicity. Virological failure within 48 weeks was rarely observed (3.3%, n = 53). In multilevel, multivariate analysis, infection with subtype B (P = 0.011), baseline CD4 count <200 cells/mm³ (P < 0.001), GSS <3 (P = 0.002) and use of lamivudine (P < 0.001) were associated with a higher risk of virological failure. After exclusion of patients using co-formulated compounds, virological failure was still more often observed with lamivudine. Following virological failure, three-quarters of patients switched to a PI-based regimen with GSS <3. After 1 year of second-line therapy, viral load was suppressed to <50 copies/mL in 73.5% (OT).

CONCLUSIONS

In clinical practice, treatment failure on TELE regimens is relatively frequent due to toxicity. Virological failure is rare and more often observed with lamivudine than with emtricitabine. Following virological failure on TELE, PI-based second-line therapy was often successful despite GSS <3.

European Academy of Paediatrics Research in Ambulatory Setting network (EAPRASnet): a multi-national general paediatric research network for better child health

BACKGROUND

In 2008, the European Academy of Paediatrics launched a paediatric-based research network - EAPRASnet (European Academy of Paediatrics Research in Ambulatory Setting network). The network has recruited primary care and general paediatricians from European and Mediterranean countries.

METHODS

Every paediatrician joining the network has been asked to complete a recruitment survey. The aims of the survey were to characterize paediatrician's demographics, practice arrangements and patient's demographics, to define main incentives for research, and to learn what paediatricians view as unsolved issues that need to be studied.

RESULTS

A total of 156 paediatricians from 19 countries were recruited with 144 completing the questionnaire (92%). Majority of respondents (89%) were general paediatricians for more than half of their time. Practice arrangement of 47% of paediatricians was solo practice, with 40% in group practice. Electronic medical records were being used by 72% of respondents. Over 70% of the paediatricians had more than 1000 patients under their clinical care, and patients younger than 6 years old contributed nearly half of the patient population. Areas of most interest for research were: quality of care indicators, communication with parents, obesity, attention deficit hyperactivity disorder and effective well child care. Main incentives for participation in a research project were interest in the topic (81%) and effort to improve quality of care (71%). Lack of time was the leading reported obstacle for research activity (72%). EAPRASnet is growing, and the network's structure, operation and funding are described. Methods for joining the network and the process of study development are presented.

CONCLUSION

A core group of EAP general paediatricians are committed to research in their practices. The information gathered will serve for future planning of research projects in the EAPRASnet to harmonize and optimize the care given to children in the primary care setting in Europe.

Bayesian network analysis of resistance pathways against HIV-1 protease inhibitors

Interpretation of Human Immunodeficiency Virus 1 (HIV-1) genotypic drug resistance is still a major challenge in the follow-up of antiviral therapy in infected patients. Because of the high degree of HIV-1 natural variation, complex interactions and stochastic behaviour of evolution, the role of resistance mutations is in many cases not well understood. Using Bayesian network learning of HIV-1 sequence data from diverse subtypes (A, B, C, F and G), we could determine the specific role of many resistance mutations against the protease inhibitors (PIs) nelfinavir (NFV), indinavir (IDV), and saquinavir (SQV). Such networks visualize relationships between treatment, selection of resistance mutations and presence of polymorphisms in a graphical way. The analysis identified 30N, 88S, and 90M for nelfinavir, 90M for saquinavir, and 82A/T and 46I/L for indinavir as most probable major resistance mutations. Moreover we found striking similarities for the role of many mutations against all of these drugs. For example, for all three inhibitors, we found that the novel mutation 89I was minor and associated with mutations at positions 90 and 71. Bayesian network learning provides an autonomous method to gain insight in the role of resistance mutations and the influence of HIV-1 natural variation. We successfully applied the method to three protease inhibitors. The analysis shows differences with current knowledge especially concerning resistance development in several non-B subtypes.

Analysis of HIV-1 pol sequences using Bayesian Networks: implications for drug resistance

Human Immunodeficiency Virus-1 (HIV-1) antiviral resistance is a major cause of antiviral therapy failure and compromises future treatment options. As a consequence, resistance testing is the standard of care. Because of the high degree of HIV-1 natural variation and complex interactions, the role of resistance mutations is in many cases insufficiently understood. We applied a probabilistic model, Bayesian networks, to analyze direct influences between protein residues and exposure to treatment in clinical HIV-1 protease sequences from diverse subtypes. We can determine the specific role of many resistance mutations against the protease inhibitor nelfinavir, and determine relationships between resistance mutations and polymorphisms. We can show for example that in addition to the well-known major mutations 90M and 30N for nelfinavir resistance, 88S should not be treated as 88D but instead considered as a major mutation and explain the subtype-dependent prevalence of the 30N resistance pathway.

How much acetaminophen do paediatricians prescribe? A survey among Israeli paediatricians

OBJECTIVE

To describe the current practice of Israeli paediatricians regarding acetaminophen dosing.

METHODS

A cross-sectional survey among 200 paediatricians. The paediatricians were questioned of the recommended dose of acetaminophen, and whether they give prescriptions for acetaminophen and instruct their patients how to use it.

RESULTS

The response rate was 36%. When asked on the recommended dose of acetaminophen, 30 (42%) physicians gave doses different from the dose recommended by the Israeli formulary. Thirty (42%) of the paediatricians answered that they usually or always give prescriptions for antipyretics.

CONCLUSIONS

A large percentage of Israeli paediatricians do not provide parents proper instructions regarding the correct dosing of acetaminophen.

Drug-Resistant HIV Infection among Drug-Naive Patients in Israel

BACKGROUND

In Israel, <0.06% of the general population is infected with human immunodeficiency virus (HIV), with a much higher prevalence among specific groups. These groups are distinguished demographically by risk behavior category and by virus subtype. We investigated transmission of drug resistance within groups to assess the impact of these factors.

METHODS

Plasma samples from >15% of all patients with new diagnoses of HIV infection were randomly collected between June 1999 and June 2003. Sequences from 176 drug-naive patients included 20 of subtype A, 20 of subtype AE, 2 of subtype AC, 29 of subtype B, 100 of subtype C, and 5 of subtype F.

RESULTS

Major drug resistance mutations (protease: L90M; reverse transcriptase: M41L, K103N, V106M, M184V, Y181S, G190A, L210W, T215Y/F, and K219R) were detected in 1 subject with A subtype, 3 with subtype B, and 9 with subtype C. In addition, 1 subject with A subtypes, 2 with subtype B, and 10 with subtype C had secondary mutations (protease: M46I; reverse transcriptase: A98G, K101Q, and V108I). Only 1 patient had mutations associated with >1 class of drugs. Among subjects who contracted HIV infection in Israel, 16 of 56 (1 of 7 with subtypes A or AE, 4 of 17 with subtype B, and 11 of 32 with subtype C; P=.7-1.0) carried resistant virus--a significantly higher proportion (P<.001) than in subjects infected in other countries (10 of 120 infected).

CONCLUSIONS

Drug-resistant virus was detected in 14.8% of patients with new diagnoses of HIV infection but in 28.6% of patients known to have been infected in Israel. The implications include a need for pretreatment resistance testing and for better programs aimed at prevention of transmission, directed particularly at patients. We did not find significant differences in transmission of resistant virus between those infected with subtypes B and C, despite the different demographic background. A conclusive analysis and interpretation should await a more extensive study.

Epidemiology of adult and adolescent HIV infection in Israel: a country of immigration

In Israel, the caseload and main modes of transmission have changed dramatically since 1991 after mass immigration from countries with generalized HIV epidemics. The previous annual average (of 60 new cases) has almost quadrupled, and 68% are among heterosexuals (compared with 11.6% before). We verified all HIV/AIDS cases ever documented, redefined (according to UNAIDS/WHO definitions) and analysed those aged 13+. Between 1980-2000, HIV and AIDS were diagnosed, respectively, in 2204 and 682 adults and adolescents (cumulative HIV infection rate = 61/100 000). Of these, 65.2% are male (mean age 35.0 years old; SD = 11.0), 31.5% female (mean age 31.4 years old; SD = 10.5) (and 3.3%, sex unknown). The main modes of HIV transmission were heterosexual (45%), MSM (16.9%) and IDUs (11.5%). Prevention measures must be strengthened, if the currently low-level of HIV epidemic among the Israeli general population is to be sustained.

Comparison of efficiency and preference of metal and plastic spacers in preschool children

BACKGROUND

The metal NebuChamber valved holding chamber (VHC) has gained wide acceptance among children with asthma. Due to its nonelectrostatic properties and larger volume, the 250-mL, metal NebuChamber delivers a greater mass of aerosol to a filter at the mouth compared with the commonly used 150-mL polypropylene AeroChamber VHC. Such in vitro results have been used to suggest that this may provide increased efficacy with the NebuChamber. No comparative efficacy data exist for preschool children with asthma.

OBJECTIVE

To compare efficiency and preference of metal and plastic spacers in preschool children.

METHODS

Children with mild-to-moderate persistent asthma received 200 microg of budesonide twice daily by NebuChamber or AeroChamber, both with the mask provided in a randomized, 2-month, crossover trial. Symptom diary cards, beta-agonist use, and preference by children and parents were compared.

RESULTS

Thirty children (mean +/- SD age, 4.3 +/- 0.3 years) completed the study. There was no difference between the AeroChamber and NebuChamber in clinical efficacy outcomes. There was no difference between the AeroChamber and NebuChamber in parents' view of ease of use, design, acceptability by the children, and overall satisfaction.

CONCLUSIONS

Despite a greater total dose delivered to the mouth, the NebuChamber appears no more effective than the AeroChamber and it is not preferred by patients or parents. More parents chose to continue to use the NebuChamber after the study.

Safety of inhaled corticosteroids delivered by plastic and metal spacers

BACKGROUND

Because of its non-electrostatic properties the metal Nebuchamber (NC) valved holding chamber (VHC) delivers a greater mass of aerosol to the mouth than the polypropylene Aerochamber (AC) VHC. Delivery of more aerosol to the lungs may also increase systemic absorption of inhaled corticosteroids (ICS) and hypothalamo-pituitary-adrenal (HPA) suppression.

METHODS

Thirty children (mean 4.3 (SD 0.3) years) received 200 micro g budesonide twice daily by NC or AC, both with the mask provided, in a randomised, two month crossover trial. Twenty four hour urinary free cortisol (UFC) was determined as a measure of HPA suppression.

RESULTS

UFC decreased from 42.3 (7.8) nmol UFC/nmol creatinine control to 26.2 (2.4) (p = 0.06 v control) after AC, and to 24.5 (2.5) (p = 0.04 v control) after NC (p = 0.4 AC v NC).

CONCLUSIONS

Despite a greater total dose delivered to the mouth, NC is not associated with greater HPA suppression when using 400 micro g/day budesonide under real life conditions in young children.

Radioimmunoscintigraphy (RIS) with bectumomab (Tc99m labeled IMMU-LL2, Lymphoscan) in the assessment of recurrent non-Hodgkin's lymphoma (NHL)

The efficacy of a Tc99m-labeled anti-lymphoma antibody fragment, bectumomab [LymphoScan], was retrospectively examined in the staging of recurrent or newly diagnosed non-Hodgkin's lymphoma (NHL) [7 patients] and to assess targeting before radioimmunotherapy (RIT) [14 patients]. Performance was graded relative to conventional imaging. Tumors included 7 low-grade, 11 intermediate-grade, and 3 high-grade histologic subtypes. Computed x-ray tomography, radiogallium imaging, FDG-PET, and bone marrow biopsy defined 117 sites. Bectumomab revealed 56% of these sites. In 4 patients bectumomab uncovered five sites not evident by conventional imaging. In addition, it uncovered one site in the brain, an area not covered in the standard work-up of asymptomatic patients. Bectumomab imaging most often failed in central abdominal and thoracic locations, and excelled in revealing disease in the head and neck. Relative to Ga67 citrate imaging, the performance of bectumomab was variable, with no clear relation to anatomic location; there was better targeting of low and intermediate grade NHL. Radiogallium out-performed bectumomab imaging in 23 sites, 19 of which were in patients with high or intermediate-grade disease. Bectumomab was superior to radiogallium at six sites, five of which involved low-grade tumor.

CONCLUSION

Bectumomab shows promise as a pre-RIT probe for targeting of B-cell NHL. It excelled at defining small volume, low-grade disease. However, as a purely diagnostic agent, its performance was variable.

West Nile fever in Israel 1999-2000: from geese to humans

West Nile virus (WNV) caused disease outbreaks in Israel in the 1950s and the late 1970s. In 1998 an outbreak of WNV in goose farms and evidence of infection in dead migratory birds were reported. Consequently, human diagnostic services for WNV were resumed, including virus isolation, serology, and RT-PCR. Risk factors for infection were assessed by a serological survey in 1999, which revealed a seroprevalence of (a) 86% in people who had close contact with sick geese, (b) 28% in people in areas along bird migration routes, and (c) 27% in the general population. Following two fatal cases in Tel Aviv in September 1999 and one encephalitis case in the southern Eilot region, a regional serological survey was initiated there. The survey revealed two more WNV-associated acute encephalitis cases, an IgG seroprevalence of 51%, and an IgM seroprevalence of 22%. In the summer of 2000, acute cases of WN disease were identified in the central and northern parts of Israel, involving 439 people. The outbreak started in mid-August, peaked in September, and declined in October, with 29 fatal cases, primarily in the elderly. During the outbreak, diagnosis was based on IgM detection. Four virus isolates were subsequently obtained from preseroconverted frozen sera. Sequence and phylogenetic analysis of 1662 bases covering the PreM, M, and part of the E genes revealed two lineages. One lineage was closely related to a 1999 Israeli bird (gull) isolate and to a 1999 New York bird (flamingo) isolate, and the other lineage was closely related to a 1997 Romanian mosquito isolate and to a 1999 Russian human brain isolate.

Autoreactivity, dynamic tuning and selectivity

The immune system adjusts its response to the context in which antigens, including self-antigens, are recognized. Recent observations support a conceptual framework for understanding how this may be achieved at the cellular and cell-population levels. At both levels, 'perturbations' elicit competition between excitation and de-excitation, resulting either in adaptation or in various responses. The responsiveness of individual cells is dynamically tuned, reflecting their recent experience. The tuning of T-cell activation thresholds by self-ligands facilitates positive selection and continuously regulates the level of autoreactivity in the periphery. Autoreactivity appears to be involved in regulation of the immune response, homeostasis, maintaining of the functional integrity of naïve and memory cells, and in other physiological functions.

Genotypic variation of HIV-1 reverse transcriptase and protease: comparative analysis of clade C and clade B

OBJECTIVE

To compare drug-resistant variants from untreated (naive) and treated patients infected with clade B or C virus.

METHODS

Consecutive samples (165) from patients throughout Israel were analyzed. All those in the treated group were failing highly active antiretroviral therapy.

RESULTS

There were 87 clade B (14 naive) and 78 clade C (20 naive) [corrected] with significant differences in the prevalence of known drug-resistance mutations between the clades: in naive patients in the protease region M36I 7% and 95% (P < 0.0001), K20R 0% and 27% (P = 0.063), A71V 18% and 0% (P = 0.063), M46I 0% and 13%, and V77I 18% and 0% (P = 0.063), respectively, and in the reverse transcriptase region A98G/S 0% and 20% (P = 0.12), respectively. Most clade C viruses also showed significant differences from clade B consensus sequence at additional protease sites: R41K 100%, H69K/Q 85%, L89M 95% and I93L 80% (P < 0.0001). There were also significant differences (P < 0.03 to < 0.0001) in treated patients in clades B and C: in the protease region L10I 40% and 12%, M36I 26% and 95%, L63P 67% and 40%, A71I 38% and 7%, G73I and V77I 18% and 0%, I84V 16% and 3%, and L90M 40% and 12%, respectively; in the reverse transcriptase M41L 41% and 17%, D67N 41% and12%, K70R 30% and 7%, T215Y 48% and 29%, K219Q 21% and 7%, and A98G/S 3% and 24%, respectively.

CONCLUSION

Significantly differences between clade B and C viruses may be associated with development of differing resistance patterns during therapy and may affect drug utility in patients infected with clade C.

Isolation and characterization of West Nile virus from the blood of viremic patients during the 2000 outbreak in Israel

We report the isolation of West Nile (WN) virus from four patient serum samples submitted for diagnosis during an outbreak of WN fever in Israel in 2000. Sequencing and phylogenetic analysis revealed two lineages, one closely related to a 1999 New York isolate and the other to a 1999 Russian isolate.

Evaluation of ELISA-based sero-diagnosis of dengue fever in travelers

Diagnosis of dengue virus infection in travelers is often based on commercially available ELISA-based serological assays and not on the more difficult and costly procedures of Hemagglutination inhibition (HI), virus isolation or RT-PCR. These standard assays are not quantitative and are designed to diagnose primary and secondary dengue virus infections by testing for IgG and IgM antibodies. However, cross reactivity between various flaviviruses and the fact that most travelers today are prevaccinated against Japanese encelphalitis (JE) and yellow fever (YF) create a potential problem in such diagnosis. Our study was aimed at measuring the extent of false positive diagnosis in prevaccinated travelers which we have assessed by testing for dengue IgG and IgM antibodies in a group of prevaccinated healthy travelers using the PanBio indirect IgG ELISA and IgM capture ELISA kits. The IgM test was negative in all healthy vaccinees, thus, being highly specific. However, the kit had a disadvantage, which was recognized in other travelers clinically ill with dengue fever (DF), in which the IgM response was detected only 4-8 days after onset of the clinical symptoms. The IgG test yielded 11-17 and 15-44% positives in healthy travelers vaccinated against JE and YF, respectively. We conclude that the specificity of the IgG-ELISA assay in prevaccinated travelers is much lower than in unvaccinated populations. Thus, an IgG-positive results in a vaccinated traveler and IgM negative result during the 1st week of the illness period, are both inconclusive.

Evaluation of ELISA-based sero-diagnosis of dengue fever in travelers

Diagnosis of dengue virus infection in travelers is often based on commercially available ELISA-based serological assays and not on the more difficult and costly procedures of Hemagglutination inhibition (HI), virus isolation or RT-PCR. These standard assays are not quantitative and are designed to diagnose primary and secondary dengue virus infections by testing for IgG and IgM antibodies. However, cross reactivity between various flaviviruses and the fact that most travelers today are prevaccinated against Japanese encelphalitis (JE) and yellow fever (YF) create a potential problem in such diagnosis. Our study was aimed at measuring the extent of false positive diagnosis in prevaccinated travelers which we have assessed by testing for dengue IgG and IgM antibodies in a group of prevaccinated healthy travelers using the PanBio indirect IgG ELISA and IgM capture ELISA kits. The IgM test was negative in all healthy vaccinees, thus, being highly specific. However, the kit had a disadvantage, which was recognized in other travelers clinically ill with dengue fever (DF), in which the IgM response was detected only 4-8 days after onset of the clinical symptoms. The IgG test yielded 11-17 and 15-44% positives in healthy travelers vaccinated against JE and YF, respectively. We conclude that the specificity of the IgG-ELISA assay in prevaccinated travelers is much lower than in unvaccinated populations. Thus, an IgG-positive results in a vaccinated traveler and IgM negative result during the 1st week of the illness period, are both inconclusive.

Changing epidemiology of dengue fever in travelers to Thailand

A study was conducted to evaluate the incidence and seasonal pattern of dengue fever occurring among Israeli travelers to Southeast Asia. The illness was diagnosed by Israeli physicians stationed abroad and by serological methods carried out in Israel. Between 1994 and 1998 dengue fever was confirmed in 103 travelers, 80 of whom were diagnosed in Israel. A sharp increase in the incidence was noted in 1998 as compared with the previous 4 years. The attack rate during 1998 in a defined group of travelers was 3.4/1,000 and reached a peak of 5/1,000 during the dry season of 1998.

Self-tolerance: context dependent tuning of T cell antigen recognition

Physiological messages to cells are encoded in the magnitude, and in the time- and space-contingencies, of sets of stimuli. In particular, individual T cells continuously integrate antigenic and other signals and respond differentially to the rate of change in the level of stimulation, translated intracellularly into 'metabolic perturbations'. The organization of the immune response at the cell-population level in space and time is also conductive to discriminating the magnitude of 'system perturbations'. In this way, the immune system was 'designed' to respond in a characteristic explosive way mainly to episodes of infection and not to the continuous presence of self-antigens. T cells are selected to be moderately autoreactive, and the degree of autoreactivity that they express is continuously controlled through activation-threshold tuning. Their level of autoreactivity is maintained in a range that facilitates survival and self-renewal and is probably used in performing some immunoregulatory functions and possibly other physiological functions. Autoreactivity and outward-directed immunity are regulated simultaneously and interactively through the interplay of selection, tuning, controlled activation and feedback.

Resolution of the pathways of poliovirus type 1 transmission during an outbreak

An outbreak of poliomyelitis with 20 cases occurred in Israel, Gaza, and the West Bank from October 1987 to October 1988. The wild type 1 poliovirus associated with the outbreak was most closely related to viruses found in the Nile Delta. The epidemiologic links among patients involved in the outbreak and patients with community-acquired infections during the outbreak were inferred from the evolutionary relationships among isolates of the outbreak virus. Complete VP1 sequences (906 nucleotides) were determined for 12 clinical and 4 sewage isolates. A total of 58 nucleotide differences were found among the 16 isolates; 74% of all substitutions were synonymous third-position transitions. An evolutionary tree, representing both the pathways of VP1 sequence evolution and the inferred chains of virus transmission during the outbreak, was constructed under the assumption that each substitution had occurred only once. The combined epidemiologic and molecular data suggest that a single founder strain was introduced into Israel from the vicinity of Gaza in the fall of 1987. Poliovirus circulation was apparently localized to southern communities during the winter and spread north by the following summer into the Hadera subdistrict of Israel, where it radiated via multiple chains of transmission into other communities in northern Israel and the West Bank. The close sequence matches (>99%) between clinical and sewage isolates from the same communities confirm the utility of environmental sampling as a tool for monitoring wild poliovirus circulation.

Evaluation of the approach of primary care physicians to the management of streptococcal pharyngotonsillitis. IPROS Network

BACKGROUND

Streptococcal pharyngotonsillitis remains a common illness in children and can lead to serious complications if left untreated.

OBJECTIVE

To evaluate the diagnostic and management approach of a sample of primary care physicians in the largest sick fund in Israel to streptococcal pharyngotonsillitis in children.

METHODS

A questionnaire was mailed to all physicians who treat children and are employed by the General Health Services (Kupat Holim Klalit) in the Jerusalem District. The questionnaire included data on demographics, practice type and size, and availability of throat culture and rapid strep test; as well as a description of three hypothetical cases followed by questions relating to their diagnosis and treatment.

RESULTS

Of the 188 eligible physicians, 118 (62.5%) responded, including 65 of 89 pediatricians (73%) and 53 of 99 family and general practitioners (53.5%). Fifty-six physicians (47.4%) had more than 18 years experience, and 82 (70%) completed specialization in Israel. Mean practice size was 950 patients. Fifty-three physicians (43%) worked in Kupat Holim community clinics, 25 (21%) worked independently in private clinics, and 40 (34%) did both. A total of 91 (77%) had access to laboratory facilities for daily throat culture. The time it took for the results to arrive was 48 to 72 hours. For the three clinical scenarios, 90% of the physicians accurately evaluated case A, a 1-year-old with viral pharyngotonsillitis, and 100 (85%) correctly diagnosed case C, a 7-year-old with streptococcal infection. As expected, opinions were divided on case B, a 3-year-old child with uncertain diagnosis. Accordingly, 75 (65.3%) physicians did not recommend treatment for case A, compared to 109 (92.5%) for case C. For case B, 22 (19%) said they would always treat, 43 (36%) would sometimes treat, and 35 (30%) would await the result of the throat culture. For 104 (88%) physicians the antibiotic of choice for case C was penicillin, while only 9 (7.5%) chose amoxicillin. However, the recommended dosage regimens varied from 250 to 500 mg per dose, and from two to four doses daily. For case C, 110 physicians (93%) chose a 10 day duration of treatment.

CONCLUSIONS

The primary care physicians in the sample (pediatricians, general practitioners and family physicians) accurately diagnosed viral and streptococcal pharyngotonsillitis. However, there was a lack of uniformity regarding its management in general, and the dosage regimen for penicillin in particular.

[Pediatric research in an office-setting network--a new dimension in pediatric research in Israel]

Pediatric care in the community is gradually replacing traditional care in hospitals. Despite that, research activity in the community setting is minimal due to objective difficulties. These are mainly constraints of time, office work and lack of research-supporting logistics. In the past decade, throughout the world, primary physicians interested in research have grouped together and formed research networks. The aim of such networks is to support and promote research in the community. An Israel Pediatric Research in Office-Setting network (IPROS) was established 2 years ago by the Israel Ambulatory Pediatric Association (IAPA). Today, there are over 140 pediatricians listed in IPROS, representing the heterogeneous composition of pediatricians in Israel. The network's policy is defined by a joint steering committee. The committee is composed of IAPA representatives, senior network members and Schneider Hospital senior investigators. The research subjects are diverse, and represent common practical issues. Effective intra-net communication is vital to the existence of the network, and is accomplished by 3 modalities: 1) semiannual updates by mail, 2) e-mail, using an electronic mailing list to facilitate connection between members, 3) semi-annual meetings. Research budgets are derived from public sources like the Ministry of Health and IAPA, and private sources such as pharmaceutical companies. The administration of the network is supported by Schneider Children's Medical Center, and financed by IAPA.

Functional magnetic resonance (fMR) imaging of a rat brain tumor model: implications for evaluation of tumor microvasculature and therapeutic response

Functional MR (fMR) imaging techniques based on blood oxygenation level dependent (BOLD) effects were developed and applied to a rat brain tumor model to evaluate the potential utility of the method for characterizing tumor growth and regression following treatment. Rats bearing 9L brain tumors in situ were imaged during inhalation of room air and after administration of 100% oxygen + acetazolamide (ACZ) injected 15 mg/kg intravenously. Pixel-to-pixel fMR maps of normalized signal intensity change from baseline values were calculated from T2 weighted spin echo (SE) images acquired pre- and post- oxygen + ACZ administration. Resultant fMR maps were then compared to gross histological sections obtained from corresponding anatomical regions. Regions containing viable tumor with increased cellular density and localized foci of necrotic tumor cells consistent with hypoxia were visualized in the fMR images as regions with decreased signal intensities, indicating diminished oxyhemoglobin concentration and blood flow as compared to normal brain. Histological regions having peritumor edema, caused by increased permeability of tumor vasculature, were visualized in the fMR images as areas with markedly increased signal intensities. These results suggest that fMR imaging techniques could be further developed for use as a non-invasive tool to assess changes in tumor oxygenation/hemodynamics, and to evaluate the pharmacologic effect of anti-neoplastic drugs.

HIV infection: how effective is drug combination treatment?

The rate of decline of plasma HIV RNA in patients treated with anti-retroviral drugs has been postulated to reflect the half-lives of previously HIV-infected cells. Here, Zvi Grossman and colleagues argue that the observed decline is explained by the kinetics of ongoing infection cycles. Residual cell-to-cell infection that becomes increasingly difficult to block could stabilize cellular provirus reservoirs.

Translation of vascular endothelial growth factor mRNA by internal ribosome entry: implications for translation under hypoxia

Vascular endothelial growth factor (VEGF) is a hypoxia-inducible angiogenic growth factor that promotes compensatory angiogenesis in circumstances of oxygen shortage. The requirement for translational regulation of VEGF is imposed by the cumbersome structure of the 5' untranslated region (5'UTR), which is incompatible with efficient translation by ribosomal scanning, and by the physiologic requirement for maximal VEGF production under conditions of hypoxia, where overall protein synthesis is compromised. Using bicistronic reporter gene constructs, we show that the 1,014-bp 5'UTR of VEGF contains a functional internal ribosome entry site (IRES). Efficient cap-independent translation is maintained under hypoxia, thereby securing efficient production of VEGF even under unfavorable stress conditions. To identify sequences within the 5'UTR required for maximal IRES activity, deletion mutants were analyzed. Elimination of the majority (851 nucleotides) of internal 5'UTR sequences not only maintained full IRES activity but also generated a significantly more potent IRES. Activity of the 163-bp long "improved" IRES element was abrogated, however, following substitution of a few bases near the 5' terminus as well as substitutions close to the translation start codon. Both the full-length 5'UTR and its truncated version function as translational enhancers in the context of a monocistronic mRNA.

Multiple modes of cellular activation and virus transmission in HIV infection: a role for chronically and latently infected cells in sustaining viral replication

CD4(+) T cell activation, required for virus replication in these cells, occurs in local microenvironmental domains in transient bursts. Thus, although most HIV originates from short-lived virus-producing cells, it is unlikely that chronic infection is generally sustained in rapid continuous cycles of productive infection as has been proposed. Such continuity of productive infection cycles would depend on efficient long-range transmission of HIV from one set of domains to another, in turn requiring the maintenance of sufficiently high concentrations of cell-free virus across lymphoid tissues at all times. By contrast, long-lived cellular sources of HIV maintain the capacity to infect newly activated cells at close range despite the temporal and spatial discontinuities of activation events. Such proximal activation and transmission (PAT) involving chronically and latently infected cells may be responsible for sustained infection, particularly when viral loads are low. Once CD4 cells are productively infected through PAT, they can infect other activated cells in their immediate vicinity. Such events propagate locally but generally do not spread systemically, unlike in the acute phase of the infection, because of the early establishment of protective anergy. Importantly, antiretroviral drug treatment is likely to differentially impact long-range transmission and PAT.

Conservation of total T-cell counts during HIV infection: alternative hypotheses and implications

While CD4+ T-cell counts in the blood of HIV-infected individuals gradually decrease, there is a parallel increase in the number of blood CD8+ T cells such that the total number of T cells remains essentially constant for several years (1). The basis and significance of this phenomenon are not known. Based on a statistical analysis of longitudinal T-cell counts from the Transfusion Safety Study (TSS) database and on theoretical considerations, we evaluate several alternative models, including versions of the "blind homeostasis" (BH) hypothesis (1-3). At issue is the nature of the homeostatic regulation of lymphocytes and its apparent failure in HIV infection. The most plausible explanation for the conservation of total blood T-cell numbers while subset ratios change is that CD4+ and CD8+ T cells compete for a limited access to the blood compartment. Such interaction between the subsets implies, in particular, that changes in the number of CD4+ T cells occurring in other tissues cannot be reliably inferred from those observed in the blood. We reiterate propositions made earlier (4) that much of the apparent "depletion" of CD4+ lymphocytes during the asymptomatic phase of HIV infection may be attributed to redistribution between the tissues and the blood compartment.

Detection of adeno-associated virus type 2 sequences in the human genital tract

Adeno-associated virus (AAV) is a defective parvovirus with unknown pathogenicity. It requires helper functions for its normal replication in human tissue and therefore is not readily isolated from clinical specimens. We have used the PCR method to examine the following clinical samples for the presence of AAV sequences: (i) 15 nasopharyngeal aspirates from symptomatic patients, (ii) 7 swab or fluid specimens from vesicles of patients suspected of having varicella-zoster virus infections, (iii) 21 human papilloma virus-positive genital biopsy specimens, (iv) 61 genital swab specimens from women suspected of having herpes simplex virus (HSV) infection examined either directly or following propagation in tissue culture, (v) 62 samples of first-trimester aborted material, including 38 samples from spontaneous abortions and 24 samples from induced abortions, (vi) 11 samples of chorionic villi taken from women undergoing genetic prenatal diagnosis, and (vii) three lots of cultured human embryonic cells. AAV sequences were detected only in samples taken from the genital tracts of women suspected of having HSV infection and not in any of the other types of samples. Samples from 11 patients were positive for AAV: for 4 patients the original swab sample was positive, for 4 patients the cultured swab sample was positive, and for 3 patients both the original swab samples and the cultures were positive. Five of the 11 patients were infected with HSV. Our study demonstrates the presence of AAV in the female genital tract. However, in contrast to a previous report (E. Tobiasch, M. Rabreau, K. Geletneky, S. Larue-Charlus, F. Severin, N. Becker, and J. R. Schlehofer, J. Med. Virol. 44:215-222, 1994), we did not find solid evidence of its replication in maternal or embryonal tissues from the first trimester of pregnancy. The questions of a potential pathogenic etiology of AAV and the interaction with HSV remain open.

Tuning of activation thresholds explains flexibility in the selection and development of T cells in the thymus

Immature CD4+ CD8+ thymocytes expressing T-cell antigen receptors (TCR) are selected by TCR-mediated recognition of peptides associated with major histocompatibility complex molecules on thymic stromal cells. Selection ensures reactivity of the mature cells to foreign antigens and tolerance to self. Although much has been learned about the factors that determine whether a thymocyte with a given specificity will be positively or negatively selected, selection as an aspect of the developmental process as a whole is less well-understood. Here we invoke a model in which thymocytes tune their response characteristics individually and dynamically in the course of development. Cellular development and selection are driven by receptor-mediated metabolic perturbations. Perturbation is a measure of the net intracellular change induced by external stimulation. It results from the integration of several signals and countersignals over time and therefore depends on the environment and the maturation stage of the cell. Individual cell adaptation limits the range of perturbations. Such adaptation renders thymocytes less sensitive to the level of stimulation per se, but responsive to environmental changes in that level. This formulation begins to explain the mechanisms that link developmental and selection events to each other.

The genome of the THE I human transposable repetitive elements is composed of a basic motif homologous to an ancestral immunoglobulin gene sequence

Amplification of rearranged human immunoglobulin heavy-chain genes using the polymerase chain reaction resulted unexpectedly in the amplification of human transposable repetitive element genomes. These were identified as members of the THE I (transposon-like human element I) transposable element family. Analysis of the THE I sequences revealed the presence of several copies of the ancestral building block described > 10 years ago by Ohno and coworkers as the primordial immunoglobulin sequence. The frequency and degree of homology of the repeats of the basic unit were similar for the two genes, as well as for two murine intracisternal A particles. These findings suggest that both the transposable genetic elements and the immunoglobulin genes originated from a common ancestral building block.

Cloning and characterization of the SmIMP25 integral membrane protein of the parasitic helminth Schistosoma mansoni

The cDNA and genomic clones encoding a 25 kDa integral membrane protein, termed SmIMP25, were isolated from Schistosoma mansoni. The 2.2 kb SmIMP25 mRNA was found in all developmental stages of the parasite tested: miracidium, sporocyst, cercaria and adult worm. The SmIMP25 gene is at least 16 kb long and it is split by four introns ranging in size from 36 bp to > or = 9 kb. Excluding the introns, the gene and the cDNA show 100% sequence identity. The cDNA has an open reading frame encoding a protein 223 amino acids long. The predicted sequence reveals a distinct hydrophobic domain of 20 amino acids located 12 residues from the carboxyl-terminal end. The properties of this domain (marked hydrophobicity, size, flanking by charged residues and C-terminal location) are typical of the transmembrane segments of integral membrane proteins. The presence of three potential N-glycosylation sites is also consistent with membrane proteins that are often glycosylated at the extracellular domain. Accordingly we propose that SmIMP25 is an integral membrane protein in which residues 1-191 are extracellular, residues 192-211 comprise the hydrophobic domain that spans the membrane, and residues 212-223 are intracellular. The SmIMP25 was synthesized as a fusion protein in bacteria and antibodies were elicited in rabbits. Antibodies against SmIMP25 specifically precipitated a 25 kDa protein from cell-free products programmed by schistosome mRNA, in agreement with the size of the protein predicted from the cDNA sequence. Immunofluorescence studies showed SmIMP25 on the surface of the parasite. Surface molecules expressed at the host-parasite interface are likely to provide information on host parasite relationship and may serve as targets for protective immunity.

Biased representation of immunoglobulin heavy chain variable region subgroups in chronic lymphocytic leukemia

The distribution of three immunoglobulin heavy chain variable region gene subgroups (VH1, 3 and 5) was investigated, using the polymerase chain reaction technique, in 53 patients with chronic lymphocytic leukemia. Thirty-seven patients displayed rearrangements of one of the above three gene segments. Over-representation of the VH5 subgroup was observed relative to its small size.

From HIV infection to AIDS: are the manifestations of effective immune resistance misinterpreted?

Viewing the immune system as part of an adaptive communication network, rather than merely a coalition of effectors, we argue that the alterations in the immune system that occur in HIV-infected patients, generally considered to be "abnormalities," cannot be attributed directly to deleterious effects of the virus on CD4+ T cells or other particular cells. Rather, many of the functional changes that occur during the asymptomatic phase reflect a normal mode of immune resistance to chronic infection, different from the "stereotypic" immune response, whereby patterns of signals are recognized and classified and evoke selective activities. The relative stability of the virus-host relationship in this phase involves a degree of mutual adaptation. However, an excessively perturbed microenvironment is the core of unstable cellular organization in which the resistance to infection gradually deteriorates. We suggest that this is due to "overadaptation" of lymphocytes and accessory cells to the infectious agent(s). We further speculate that a key factor underlying this process is a reduced rate of replacement of CD4+ T cells, which are sequestered at the sites of infection, by fresh unprimed or memory T cells. Direct and local viral effects are amplified and propagated by "affected" cells, which are not necessarily infected. The collective profile of gene expression in various types of affected cells might adequately reflect tissue organization and the overall functional status of the immune system and thus could serve as a guide to therapy. This would require collection of a more extensive array of immunologic data than is now gathered, and novel approaches to analyzing such data.

Analysis of rearranged immunoglobulin genes indicating a process of clonal evolution in chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is known to be a stable monoclonal neoplasm. In contrast to early studies demonstrating no more than two hybridizing immunoglobulin heavy chain bands corresponding to the two expected alleles, we have demonstrated an unexpected multiband pattern when the HindIII-digested DNA samples from 38 CLL patients were analysed by Southern blot hybridization using JH and C mu gene probes. In order to characterize the genetic basis for the multiband pattern, we molecularly cloned the immunoglobulin heavy chain genes of one of the patients whose leukaemic DNA sample demonstrated three hybridizing JH bands and a loss of the germline band. The cloned rearranged immunoglobulin genes could be divided, based on the restriction mapping and the hybridization with the various probes, into two basic patterns representing two alleles. In one of the cloned rearranged immunoglobulin genes a secondary rearrangement occurred that resulted in the addition of 300 base-pair long sequence into the switch region, and the creation of a HindIII restriction site. The results of the study suggest that clonal evolution occurs in some CLL, and that many of these neoplasms are indeed oligoclonal due to the accumulation of secondary genetic changes.

Cellular tolerance as a dynamic state of the adaptable lymphocyte

The regulation of immunological tolerance is considered from the perspective of contextual discrimination, rather than self-nonself discrimination. According to the adaptive lymphocyte hypothesis, the scale of immune aggression versus tolerance can be regulated at the cell population level, but individual cells also tune and update their responsiveness under the influence of recurrent signals. The generation of a sizeable conventional immune response, which is transient and aggressive, depends critically on the perturbation to the system, which is related to the rate of appearance of the immunizing agent. These characteristics are explained in quantitative terms by the "balance of growth and differentiation model". Strong perturbations are typically associated, physiologically, with acute infections. Full activation of individual lymphocytes also requires strong metabolic perturbations, where the perturbation is defined as a measure of variation in the intensity of stimulation. Cells that fail to be activated in this way may be driven into a state which formally conforms to the operational definition of anergy. This state is characterized by a variable degree of resistance to the stereotypic mode of activation for which the cell has been programmed before. While in this state, the cell interacts with its environment: these interactions promote its viability, update its activation thresholds and its excitability, and may reprogram the cell for a different mode of response when activated later. In addition, cells engaged in such interactions may mediate context-dependent immunological functions. The characteristics of the interactions involving such anergic cells are discussed in semi-quantitative terms with the help of the "tunable activation-thresholds model". Several aspects of immunological tolerance are interpreted in a unifying way based on this conceptual framework. It is suggested that progress in our ability to evaluate and manipulate the regulation of immunological tolerance would require a methodology to conjoin many pieces of data together and to look for patterns.