Perinatal exposure to atazanavir-based antiretroviral regimens in a mouse model leads to differential long-term motor and cognitive deficits dependent on the NRTI backbone

Background

Combination antiretroviral therapy (ART) use in pregnancy has been pivotal in improving maternal health and reducing perinatal HIV transmission. However, children born HIV-exposed uninfected fall behind their unexposed peers in several areas including neurodevelopment. The contribution of in utero ART exposure to these deficits is not clear. Here we present our findings of neurocognitive outcomes in adult mice exposed in utero to ART.

Methods

Dams were treated with a combination of ritonavir-boosted atazanavir with either abacavir plus lamivudine (ABC/3TC + ATV/r) or tenofovir disoproxil fumarate plus emtricitabine (TDF/FTC + ATV/r), or water as a control, administered daily from day of plug detection to birth. Offspring underwent a battery of behavioral tests that investigated motor performance and cognition starting at 6-weeks of age and ending at 8 months. Changes in brain structure were assessed using magnetic resonance imaging and immunohistochemistry. Expression of genes involved in neural circuitry and synaptic transmission were assessed in the hippocampus, a region strongly associated with memory formation, using qPCR.

Findings

Pups exposed to TDF/FTC + ATV/r showed increased motor activity and exploratory drive, and deficits in hippocampal-dependent working memory and social interaction, while pups exposed to ABC/3TC + ATV/r showed increased grooming, and deficits in working memory and social interaction. Significant volumetric reductions in the brain were seen only in the ABC/3TC + ATV/r group and were associated with reduced neuronal counts in the hippocampus. Altered neurotransmitter receptor mRNA expression as well as changes in expression of the neurotrophic factor BDNF and its receptors were observed in both ART-exposed groups in a sex-dependent manner.

Interpretation

In our model, in utero ART exposure had long-term effects on brain development and cognitive and motor outcomes in adulthood. Our data show that neurological outcomes can be influenced by the type of nucleoside reverse transcriptase inhibitor backbone of the regimen and not just the base drug, and display sex differences.

Effects of supplemental antioxidants on in vitro fertility measures for cryopreserved boar spermatozoa

This work aims to evaluate how supplementing a commercial freezing media with butylated hydroxytoluene (BHT), or reduced glutathione (GSH), or their combination affected in-vitro measures of boar sperm after cryopreservation. One ejaculate was collected from 30 high-fertility boars in a weekly collection rotation. Samples were diluted 1:1 in an extender and cooled before overnight shipping at 17 °C to the freezing lab. On arrival, samples were split into the treatments with the following additions before cryopreservation; 1) semen without additional antioxidants (Control), 2) semen with 1 mM BHT, 3) semen with 2 mM GSH, and 4) semen with 1 mM BHT+2 mM GSH. Semen was evaluated for motility kinetics at 30, 120, and 240 min after thawing. Flow cytometry assessments were performed at 60 min after thawing. At all-time points evaluated, total and progressive motility were greater (P ≤ 0.05) in semen cryopreserved with GSH than in Control. No (P > 0.05) differences between Control and other treatment groups were observed in viability, or acrosomal and mitochondrial membrane integrity; however, the proportion of capacitated spermatozoa were reduced (by -21.17%) in semen treated with BHT + GSH compared to Control (P ≤ 0.05). In contrast, there was a higher (P ≤ 0.05, +21.18%) superoxide anion production in the Control than in the BHT + GSH. For IVF, semen cryopreserved with both antioxidants (BHT + GSH) had a negative (P < 0.05) impact on fertilization rate (-54.11%) compared to Control. However, for the blastocysts rate, there were more (+22.75%) blastocysts (P ≤ 0.05) for BHT compared to Control. These results indicate that commercial media supplemented with GSH increased motility but impaired in vitro fertilization rate. On the other hand, media supplemented with BHT improved the in vitro fertilizing ability of the frozen-thawed sperm cells. Therefore, we suggest the supplementation with 1 mM of BHT in the formula of commercial freezing media used in the present experiment.

Comparison of the Effects of Three Dual-Nucleos(t)ide Reverse Transcriptase Inhibitor Backbones on Placenta Mitochondria Toxicity and Oxidative Stress Using a Mouse Pregnancy Model

Nucleos(t)ide reverse transcriptase inhibitors (NRTIs) are the backbone of HIV antiretroviral therapy (ART). ART use in pregnancy has been associated with adverse birth outcomes, in part due to NRTI-induced mitochondrial toxicity. Direct comparison on the effects of commonly used dual-NRTI regimens on placental mitochondria toxicity in pregnancy is lacking. We compared zidovudine/lamivudine, abacavir/lamivudine, and tenofovir/emtricitabine using a mouse model and examined markers of placental mitochondrial function and oxidative stress. Zidovudine/lamivudine and abacavir/lamivudine were associated with lower fetal and placental weights compared to controls, whereas tenofovir/emtricitabine was associated with the least fetal and placental weight reduction, as well as lower resorption rates. Placental mitochondrial DNA content, as well as placental expression of cytochrome c-oxidase subunit-II, DNA polymerase gamma, and citrate synthase, was higher in tenofovir/emtricitabine-treated mice compared to other groups. Zidovudine/lamivudine-treated mice had elevated malondialdehyde levels (oxidative stress marker) compared to other groups and lower mRNA levels of manganese superoxide dismutase and peroxisome proliferator-activated receptor gamma coactivator 1-alpha in the placenta compared to tenofovir/emtricitabine-treated mice. We observed differences in effects between NRTI regimens on placental mitochondrial function and birth outcomes. Tenofovir/emtricitabine was associated with larger fetuses, increased mtDNA content, and higher expression of mitochondrial-specific antioxidant enzymes and mitochondrial biogenesis enzymes, whereas zidovudine/lamivudine was associated with markers of placental oxidative stress.

Persistent Nutritional Deficiency in Pancreatic-Insufficient Children and Adolescents with Cystic Fibrosis Despite Therapeutic Intervention

Background

Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF Transmembrane Conductance Regulator (CFTR) protein, resulting in compromised pulmonary function, malabsorption, and pancreatic insufficiency. The sequelae of CF are heterogeneous, and contributing factors are multifactorial. Nutritional deficiencies, particularly in essential fatty acids (EFA) and vitamins, are known to alter the trajectory of CF unfavorably. The current treatment modalities focus on proactive management of the pulmonary, gastrointestinal, and pancreatic functions; however, information on the monitoring and treatment of nutritional deficiencies in CF patients is scant. The objective of our study was to evaluate the effects of pancreatic function and CFTR modulator therapy on pertinent nutritional deficiencies in children and adolescents diagnosed with CF.

Methods

The study was approved by our institutional IRB and included 77 non-fasted CF participants, 10.4 + 5.2 years of age (range: 4 months-18 years), and an equal ratio of both sexes. Participants were stratified as pancreatic sufficient (PS, n=6), and pancreatic insufficient with (PI, n=48) or without CFTR modulator treatment (PI-M, n=23). Twenty-two fatty acids were measured in plasma by GC-MS, including omega-6 linoleic acid (LA), and omega-3 α-linoleic acid (ALA). Medical records and 24-hour dietary recalls were reviewed to correlate biochemical and clinical findings. Vitamins A and E and zinc levels of the participants were also obtained. Data analyses were performed by one-way ANOVA and Tukey’s multiple comparisons using Prism software (LaJolla, CA).

Results

There were no significant differences in BMI and caloric intake among the groups. The concentrations of EFA, LA, and ALA were significantly higher in the PS group (3904±229 nmol/mL and 149±24 nmol/mL) compared to the PI (2387±89 nmol/mL and 53±4 nmol/mL, p&lt;0.01) and PI-M (2335±159 nmol/mL and 58±7 nmol/mL, p&lt;0.01) groups, respectively. Similarly, the biologically active omega-6 arachidonic acid and omega-3 docosahexaenoic acid were lower in the PI and PI-M groups compared to the PS group (p&lt;0.05). Interestingly, EFA deficiency biomarkers, omega-9 mead acid, and the Triene:Tetraene ratio, were significantly higher in the PI group (17±2 nmol/mL and 0.033±0.003) vs PS group (13±3 nmol/mL and 0.019±0.002, p&lt;0.05), respectively. Higher concentrations of vitamins A and E were observed in the PS group vs PI-M groups (p&lt;0.05), and zinc concentrations were not different among the groups. There were no associations between the concentrations of EFA and BMI, age, total caloric intake, and % calories from fat in PS, PI, and PI-M patients.

Conclusion

While advances in CF therapeutics are remarkable, our data show the persistence of nutritional deficiencies in pancreatic insufficient CF patients regardless of CFTR modulator therapy and support the clinical utility of EFA and vitamins as potential adjuvant biomarkers to assess the severity and assist in the clinical monitoring of CF.

In utero exposure to protease inhibitor-based antiretroviral regimens delays growth and developmental milestones in mice

Antiretroviral therapy (ART) in pregnancy has dramatically reduced HIV vertical transmission rates. Consequently, there is a growing number of children that are HIV exposed uninfected (CHEUs). Studies suggest that CHEUs exposed in utero to ART may experience developmental delays compared to their peers. We investigated the effects of in utero ART exposure on perinatal neurodevelopment in mice, through assessment of developmental milestones. Developmental milestone tests (parallel to reflex testing in human infants) are reflective of brain maturity and useful in predicting later behavioral outcomes. We hypothesized that ART in pregnancy alters the in utero environment and thereby alters developmental milestone outcomes in pups. Throughout pregnancy, dams were treated with boosted-atazanavir combined with either abacavir/lamivudine (ATV/r/ABC/3TC), or tenofovir/emtricitabine (ATV/r/TDF/FTC), or water as control. Pups were assessed daily for general somatic growth and on a battery of tests for primitive reflexes including surface-righting, negative-geotaxis, cliff-aversion, rooting, ear-twitch, auditory-reflex, forelimb-grasp, air-righting, behaviors in the neonatal open field, and olfactory test. In utero exposure to either ART regimen delayed somatic growth in offspring and evoked significant delays in the development of negative geotaxis, cliff-aversion, and ear-twitch reflexes. Exposure to ATV/r/ABC/3TC was also associated with olfactory deficits in male and forelimb grasp deficits in female pups. To explore whether delays persisted into adulthood we assessed performance in the open field test. We observed no significant differences between treatment arm for males. In females, ATV/r/TDF/FTC exposure was associated with lower total distance travelled and less ambulatory time in the centre, while ATV/r/ABC/3TC exposure was associated with higher resting times compared to controls. In utero PI-based ART exposure delays the appearance of primitive reflexes that involve vestibular and sensory-motor pathways in a mouse model. Our findings suggest that ART could be disrupting the normal progress/maturation of the underlying neurocircuits and encourage further investigation for underlying mechanisms.

Comparison of Heat Fractionation and Gel Electrophoresis Methods for the Quantitative Determination of Alkaline Phosphatase Isoenzymes

Introduction

Alkaline phosphatase (ALP) is important in the diagnostic work-up for hepatobiliary and bone diseases. ALP isoenzymes are expressed in the bone, liver, kidney, placenta, and intestine, and vary in heat stability and electrophoretic mobility. Distinguishing the different ALP isoenzymes is clinically important for the diagnosis of pathologies associated with elevated ALP activity. Current modalities available to measure ALP isoenzymes utilize the heat stability, electrophoretic mobility, and immunochemical properties of the isoenzymes. The differences inherent in these methods allow for unique benefits of each method in identifying ALP isoenzymes. The objective of this study was to compare bone, liver, and placental ALP isoenzyme results determined by heat fractionation and gel electrophoresis and to characterize the heat-stable non-liver fraction (t1/2 &gt;11 min), reported by heat fractionation, using gel electrophoresis.

Methods

A total of 72 de-identified serum samples that span a wide range of known ALP isoenzyme concentrations and disease states were used to measure ALP using gel electrophoresis and heat fractionation. Heat fractionation was achieved by selective inactivation of the isoenzymes at 56 °C in 10, 15, and 20-minute intervals. Log-percent activity of the total and heat-inactivated fractions at each time point was plotted against time in minutes. The linear activity decay between 10 and 20 minutes determined the relative amount of liver isoenzyme activity and the slope of the line determined the half-lives of ALP isoenzymes. Electrophoresis was performed according to the manufacturer’s protocol using the Hydragel ISO-PAL gel to resolve ALP isoenzymes based on their electrophoretic mobility and interaction with lectin. ALP isoenzymes were quantified by densitometry.

Results

Our results show a significant correlation coefficient (r) of 0.98, Deming regression slope of 1.1, and bias of -1.2% for the liver isoenzyme (n=43). However, liver fractions are not distinguishable by heat fractionation when heat-stable isoforms are present. The bone fraction (n=43) showed a coefficient of correlation of 0.86, slope of 0.55, and bias of -31%. Although, with a small sample size (n=6), the placental isoenzyme showed a significant agreement between the two methods: r = 0.999, slope = 0.98, and a -3.5% bias. Of the non-liver fractions reported by heat fractionation (n=13, ALP &gt;100 U/L) eleven (85%) showed distinct qualitative bands in the intestinal lane on gel electrophoresis; however, quantitative values did not correlate between the two methods.

Conclusion

Our data support an agreement between the heat fractionation and gel electrophoresis methods for the quantitative determination of liver and placental alkaline phosphatase isoenzymes. Although there is an association between the two methods, the activity of the bone isoenzyme was underestimated by the gel electrophoresis method, likely due to saturation of the gel and densitometry scan because of elevated protein concentrations. The non-liver fractions were qualitatively identified as intestinal isoenzyme.

HIV coinfection among persons diagnosed with hepatitis B in England in 2008-2014

OBJECTIVES

The aim of the study was to estimate HIV prevalence among persons with hepatitis B virus (HBV) infection in England and to examine associated risk factors.

METHODS

Persons aged ≥ 15 years with an HBV surface antigen (HBsAg) test reported to Public Health England (PHE) sentinel surveillance during 2008-2014 were linked to the PHE national HIV/AIDS database. Coinfection was defined as an HIV diagnosis prior to, or within 6 months following, a positive HBsAg test.

RESULTS

During 2008-2014, 2 149 933 persons were tested for HBsAg and 3.9% (1129 of 28 789) of HBsAg-positive persons were HIV positive. The probable route of HIV infection was heterosexual exposure for 95.3% of female patients and 32.3% of male patients, with 61.5% of male patients reporting sex between men. Among African-born coinfected persons, 84% probably acquired HIV there. Predictors of HIV positivity included older age [adjusted odds ratio (aOR) 1.1] and being of black ethnicity (aOR 15.5 for males; aOR 16.4 for females) or being male and of white ethnicity (aOR 8.2) compared with being female and of white ethnicity. HIV coinfection was more likely when HBV was diagnosed in sexual health (aOR 55.0), specialist liver (aOR 6.7), emergency department (aOR 5.3) and renal services (aOR 2.8) compared with general practice. Most (60.4%; 682 of 1129) coinfected persons were diagnosed with HIV infection > 6 months before HBV diagnosis.

CONCLUSIONS

Persons testing positive for HBsAg had a low HIV infection rate and fell largely into two groups: those of black ethnicity with probable Africa-acquired infections and white men who have sex with men (MSM) with probable UK-acquired infections. Findings reinforce existing recommendations to sustain and improve both HBV testing of migrants from HBV-prevalent countries and vaccination among HIV-positive MSM. Findings also support blood-borne virus testing in sexual health services and emergency departments.

Changes to country-specific hepatitis A travel vaccination recommendation for UK travellers in 2017-responding to a vaccine shortage in the national context

OBJECTIVES

A routine review of hepatitis A travel vaccination recommendations was brought forward in June 2017 due to hepatitis A vaccine shortages and a concurrent outbreak in men who have sex with men (MSM). There were three objectives: first, to document the review process for changing the recommendations for the UK travellers in June 2017. Second, to study the impact of these changes on prescribing in general practice in 2017 compared with the previous 5 years. Third, to study any changes in hepatitis A notifications in June-October 2017 compared with the previous 5 years.

STUDY DESIGN

This is an observational study.

METHODS

Travel vaccination recommendations for countries with either low-risk (<20%) or high-risk (>90%) status according to child hepatitis A seroprevalence were not changed. A total of 67 intermediate-risk countries with existing recommendations for most travellers and with new data on rural sanitation levels were shortlisted for the analysis. Data on child hepatitis A seroprevalence, country income status, access to sanitation in rural areas and traveller volumes were obtained. Information about the vaccine supply was obtained from Public Health England. Changes to the existing classification were made through expert consensus, based on countries' hepatitis A seroprevalence, sanitation levels, level of income, volume of travel and hepatitis A traveller cases. Data on the number of combined and monovalent hepatitis A-containing vaccines prescribed in England, 2012-2017, were obtained from the National Health Service Business Service Authorities. The number of monthly prescriptions for January-September 2017 was compared with the mean number of prescriptions for the same month in the previous 5 years (t-test, α = 5%, df = 4). The number of hepatitis A cases notified in June-October 2017 not related to the MSM outbreak was compared with the number of notifications in the same months in previous years.

RESULTS

A total of 36 countries were downgraded based on good access (80+% of population) to sanitation in rural areas and the intermediate-risk status in terms of child hepatitis A seroprevalence. For these countries, vaccination would only be recommended to travellers staying long term, visiting friends and relatives or staying in areas without good sanitation. There was a significant decline in hepatitis A vaccine prescriptions in June-September 2017, and there was no increase in the number of notifications.

CONCLUSIONS

Hepatitis A vaccination recommendations for travel were revised in 2017 following a systematic approach to maintain continuity of supply after a hepatitis A vaccine shortage and increased hepatitis A vaccine demand related to a large outbreak. Improved access to good sanitation in rural areas and low seroprevalence estimates among children have led to 36 countries to no longer require vaccination for most travellers. These changes do not seem to have impacted on hepatitis A notifications in England, although further research will be needed to quantify the impact more precisely.

Low Prolactin and High 20-α-Hydroxysteroid Dehydrogenase Levels Contribute to Lower Progesterone Levels in HIV-Infected Pregnant Women Exposed to Protease Inhibitor-Based Combination Antiretroviral Therapy

BACKGROUND

It has been reported that pregnant women receiving protease inhibitor (PI)-based combination antiretroviral therapy (cART) have lower levels of progesterone, which put them at risk of adverse birth outcomes, such as low birth weight. We sought to understand the mechanisms involved in this decline in progesterone level.

METHODS

We assessed plasma levels of progesterone, prolactin, and lipids and placental expression of genes involved in progesterone metabolism in 42 human immunodeficiency virus (HIV)-infected and 31 HIV-uninfected pregnant women. In vitro studies and a mouse pregnancy model were used to delineate the effect of HIV from that of PI-based cART on progesterone metabolism.

RESULTS

HIV-infected pregnant women receiving PI-based cART showed a reduction in plasma progesterone levels (P= .026) and an elevation in placental expression of the progesterone inactivating enzyme 20-α-hydroxysteroid dehydrogenase (20α-HSD; median, 2.5 arbitrary units [AU]; interquartile range [IQR], 1.00-4.10 AU), compared with controls (median, 0.89 AU; IQR, 0.66-1.26 AU;P= .002). Prolactin, a key regulator of 20α-HSD, was lower (P= .012) in HIV-infected pregnant women. We observed similar data in pregnant mice exposed to PI-based cART. In vitro inhibition of 20α-HSD activity in trophoblast cells reversed PI-based cART-induced decreases in progesterone levels.

CONCLUSIONS

Our data suggest that the decrease in progesterone levels observed in HIV-infected pregnant women exposed to PI-based cART is caused, at least in part, by an increase in placental expression of 20α-HSD, which may be due to lower prolactin levels observed in these women.

Large and prolonged food-borne multistate hepatitis A outbreak in Europe associated with consumption of frozen berries, 2013 to 2014

In May 2013, Italy declared a national outbreak of hepatitis A, which also affected several foreign tourists who had recently visited the country. Molecular investigations identified some cases as infected with an identical strain of hepatitis A virus subgenotype IA. After additional European Union/European Economic Area (EU/EEA) countries reported locally acquired and travel-related cases associated with the same outbreak, an international outbreak investigation team was convened, a European outbreak case definition was issued and harmonisation of the national epidemiological and microbiological investigations was encouraged. From January 2013 to August 2014, 1,589 hepatitis A cases were reported associated with the multistate outbreak; 1,102 (70%) of the cases were hospitalised for a median time of six days; two related deaths were reported. Epidemiological and microbiological investigations implicated mixed frozen berries as the vehicle of infection of the outbreak. In order to control the spread of the outbreak, suspected or contaminated food batches were recalled, the public was recommended to heat-treat berries, and post-exposure prophylaxis of contacts was performed. The outbreak highlighted how large food-borne hepatitis A outbreaks may affect the increasingly susceptible EU/EEA general population and how, with the growing international food trade, frozen berries are a potential high-risk food.

Increase in hepatitis A in tourists from Denmark, England, Germany, the Netherlands, Norway and Sweden returning from Egypt, November 2012 to March 2013

Since November 2012, there has been an increase in reported cases of hepatitis A in tourists returning from Egypt in several European countries. As of 24 April, 80 HAV cases in travellers with symptom onset after 1 November 2012 visiting different areas in Egypt have been reported. Four cases from Norway, six cases from the Netherlands and five cases from England share an identical hepatitis A viral RNA sequence. This increase in cases suggests that vaccination recommendations for travellers to hepatitis A endemic countries should be reinforced.

A possible outbreak of hepatitis A associated with semi-dried tomatoes, England, July–November 2011

In October 2011, two primary cases of hepatitis A virus (HAV) infection with identical HAV genotype IB strains to those seen in other outbreaks associated with semi-dried tomatoes were reported in England. Both cases had consumed semi-dried tomatoes. Epidemiological investigations revealed two additional cases of genotype IB strains with different sequences who also reported having consumed semi-dried tomatoes. In November, five cases of HAV infection with closely related strains were identified in the Netherlands. A foodborne multiple-strain outbreak is suspected.

A possible outbreak of hepatitis A associated with semi-dried tomatoes, England, July-November 2011

In October 2011, two primary cases of hepatitis A virus (HAV) infection with identical HAV genotype IB strains to those seen in other outbreaks associated with semi-dried tomatoes were reported in England. Both cases had consumed semi-dried tomatoes. Epidemiological investigations revealed two additional cases of genotype IB strains with different sequences who also reported having consumed semi-dried tomatoes. In November, five cases of HAV infection with closely related strains were identified in the Netherlands. A foodborne multiple-strain outbreak is suspected.

Hepatitis A outbreak in an Orthodox Jewish community in London, July 2010

A cluster of hepatitis A cases in the Orthodox Jewish community in London, United Kingdom in July 2010 has triggered extensive contact tracing and vaccination. Two primary cases imported from a common source in Israel and three secondary cases have resulted in immunisation of over 900 contacts to date. Rapid response by local public health, primary care services and a dedicated community health team, and active hepatitis A vaccination rather than immunoglobulin treatment were used to avert a larger outbreak.

Hepatitis A outbreak in an Orthodox Jewish community in London, July 2010

TA cluster of hepatitis A cases in the Orthodox Jewish community in London, United Kingdom in July 2010 has triggered extensive contact tracing and vaccination. Two primary cases imported from a common source in Israel and three secondary cases have resulted in immunisation of over 900 contacts to date. Rapid response by local public health, primary care services and a dedicated community health team, and active hepatitis A vaccination rather than immunoglobulin treatment were used to avert a larger outbreak.

Hepatitis B incidence among South Asian children in England and Wales: implications for immunisation policy

The incidence of acute hepatitis B virus (HBV) infection is higher among South Asian than among non-South Asian UK residents, and infections in South Asians occur more often during childhood. The UK's immunisation policy should be changed to protect ethnic minority children against HBV infection.

Molecular epidemiology of a large outbreak of hepatitis B linked to autohaemotherapy

BACKGROUND

Unregulated skin-piercing procedures potentially facilitate the transmission of bloodborne pathogens. In February, 1998, a patient who had recently received autohaemotherapy at an alternative medicine clinic in the UK was diagnosed with acute hepatitis B. The autohaemotherapy procedure involved the drawing of 1 mL of the patient's blood, mixing with saline, and reinjection of the autologous blood mixture. We investigated the extent of hepatitis B virus (HBV) infection in patients and staff of the clinic.

METHODS

Patients who had attended the clinic between January, 1997, and February, 1998, were tested for serological markers of HBV, and for HBV DNA by PCR. HBV DNA was sequenced to assess the relatedness of the virus identified in the cases. We analysed the number and dates of visits with regard to HBV status.

FINDINGS

Serum samples were received from 352 patients and four staff members. Serological evidence of exposure to HBV was found in 57 (16%). Of the 33 patients and staff who were positive for hepatitis B surface antigen, 30 (91%) showed complete nucleotide identity in the DNA segments derived from the surface and core genes. Five patients with linked infection had markers of chronic hepatitis B, and one of these was regarded as the likely source of the outbreak. The attack rate was associated with the number of visits (p<0.0001) and the week of visit (p=0.011). Contaminated saline in a repeatedly used bottle was the probable vehicle of transmission.

INTERPRETATION

We have described a large community-based outbreak of hepatitis B due to transmission by a single HBV variant. Our findings emphasise the continuing risk of transmission of bloodborne viruses in all health-care settings where skin-piercing procedures are used.

Active surveillance of hepatitis C infection in the UK and Ireland

AIM

To investigate the prevalence, distribution, and clinical details of paediatric hepatitis C virus (HCV) infection in the UK and Ireland.

METHODS

Active monthly surveillance questionnaire study coordinated through the British Paediatric Surveillance Unit, to all consultant paediatricians in 1997 and 1998.

RESULTS

A total of 182 HCV infected children were reported from 54 centres and by paediatricians from eight different specialties. In 40 children HCV was acquired through mother to child transmission (MTC children); 142 were infected by contaminated blood products (n = 134), organ transplantation (n = 2), needles (n = 4), or unknown risk factor (n = 2). Intravenous drug use was the risk factor for 35 mothers of MTC children. Twelve children were coinfected with HIV and four with HBV. Recent serum aspartate aminotransferase or alanine aminotransferase values were at least twofold greater than the upper limit of normal in 24 of 152 children; this occurred in five of 11 HIV coinfected children. Liver histology, available in 53 children, showed normal (7%), mild (74%), moderate (17%), or severe (2%) hepatitis. Twenty eight children had received therapy with interferon alfa.

CONCLUSION

Most current paediatric HCV infection in UK and Ireland has been acquired from contaminated blood products, and most children are asymptomatic. There is a need for multicentre trials to inform clinical practice and development of good practice guidelines in this area. Long term follow up of this cohort of HCV infected children is planned to help determine the natural history over the long term of HCV acquired during infancy and childhood.

Control of hepatitis B in the United Kingdom

Control of hepatitis B in the UK is based upon selective vaccination of persons in high-risk groups. To assess the likely cost-effectiveness of changes to this policy, information on the current burden of HBV infection in the UK is required. Laboratory reports of acute hepatitis B suggest that the vast majority of new hepatitis B infections acquired in the UK occur in adults, even after adjustment for unapparent infection. In childhood, perinatal transmission remains the most significant known risk factor. Universal antenatal screening has the potential to prevent perinatal infections in UK births and a substantial proportion of those UK acquired infections which lead to carriage. In addition, to antenatal screening, universal infant vaccination (at 2, 3 and 4 months) can, in the short term, only prevent the small number of infections acquired in childhood. Economic analysis using current surveillance data is required to assess the possible cost-benefit of universal vaccination. Regardless of this, there is an urgent need to improve selective vaccination and to ensure that a high proportion of antenatal carriers is identified.