Implementing the number needed to harm in clinical practice: risk of myocardial infarction in HIV-1-infected patients treated with abacavir.

OBJECTIVES: The D:A:D study group reported a 1.9-fold increased relative risk (RR) of myocardial infarction (MI) associated with current or recent use of abacavir. The number needed to harm (NNH) incorporates information about the underlying risk of MI and the increased RR of MI in patients taking abacavir. METHODS: NNH was calculated as the reciprocal of the difference between the underlying risks of MI with and without abacavir use. A parametric statistical model was used to calculate the underlying risk of MI over 5 years. RESULTS: The relationship between NNH and underlying risk of MI is reciprocal, resulting in wide variation in the NNH with small changes in underlying risk of MI. The smallest changes in NNH are in the medium- and high-risk groups of MI. The NNH changes as risk components are modified; for example, for a patient who smokes and has a systolic blood pressure (sBP) of 160 mmHg and a 5-year risk of MI of 1.3% the NNH is 85, but the NNH increases to 277 if the patient is a nonsmoker and to 370 if sBP is within the normal range (120 mmHg). CONCLUSIONS: We have illustrated that the impact of abacavir use on risk of MI varies according to the underlying risk and it may be possible to increase considerably the NNH by decreasing the underlying risk of MI using standard of care interventions, such as smoking cessation or control of hypertension.

Isolation of lytic bacteriophage against Vibrio harveyi.

AIMS: The isolation of lytic bacteriophage of Vibrio harveyi with potential for phage therapy of bacterial pathogens of phyllosoma larvae from the tropical rock lobster Panulirus ornatus. METHODS AND RESULTS: Water samples from discharge channels and grow-out ponds of a prawn farm in northeastern Australia were enriched for 24 h in a broth containing four V. harveyi strains. The bacteriophage-enriched filtrates were spotted onto bacterial lawns demonstrating that the bacteriophage host range for the samples included strains of V. harveyi, Vibrio campbellii, Vibrio rotiferianus, Vibrio parahaemolyticus and Vibrio proteolyticus. Bacteriophage were isolated from eight enriched samples through triple plaque purification. The host range of purified phage included V. harveyi, V. campbellii, V. rotiferianus and V. parahaemolyticus. Transmission electron microscope examination revealed that six purified phage belonged to the family Siphoviridae, whilst two belonged to the family Myoviridae. The Myoviridae appeared to induce bacteriocin production in a limited number of host bacterial strains, suggesting that they were lysogenic rather than lytic. A purified Siphoviridae phage could delay the entry of a broth culture of V. harveyi strain 12 into exponential growth, but could not prevent the overall growth of the bacterial strain. CONCLUSIONS: Bacteriophage with lytic activity against V. harveyi were isolated from prawn farm samples. Purified phage of the family Siphoviridae had a clear lytic ability and no apparent transducing properties, indicating they are appropriate for phage therapy. Phage resistance is potentially a major constraint to the use of phage therapy in aquaculture as bacteria are not completely eliminated. SIGNIFICANCE AND IMPACT OF THE STUDY: Phage therapy is emerging as a potential antibacterial agent that can be used to control pathogenic bacteria in aquaculture systems. The development of phage therapy for aquaculture requires initial isolation and determination of the bacteriophage host range, with subsequent creation of suitable phage cocktails.

Prediction of phenotypic susceptibility to antiretroviral drugs using physiochemical properties of the primary enzymatic structure combined with artificial neural networks.

OBJECTIVES: Genotypic interpretation systems extrapolate observed associations in datasets to predict viral susceptibility to antiretroviral drugs (ARVs) for given isolates. We aimed to develop and validate an approach using artificial neural networks (ANNs) that employ descriptors of physiochemical properties for mutations in HIV-1 protease (PR) and reverse transcriptase (RT) to predict phenotypic susceptibility to all currently approved ARVs. METHOD: We extracted pairs of PR and RT gene sequences (n=1507; 98.5% sub-type B) and their corresponding exact phenotype values (PhenoSense only, n=10 132) from the Stanford HIV database. All amino acid positions and mixture codes were accounted for. For each ARV, an ANN was trained with 10-fold internal cross-validation. The predictive abilities of these trained ANNs were validated on separate datasets. RESULTS: Correlation coefficients between observed and predicted phenotype values in the 10-fold cross-validation ranged from: 0.75 (tenofovir) to 0.94 [lamivudine (3TC)] for nucleoside RT inhibitors (NRTIs); 0.82 [efavirenz (EFV)] to 0.83 [nevirapine (NVP)] for non-nucleoside RT inhibitors (NNRTIs); and 0.83 (atazanavir) to 0.92 (ritonavir) for PR inhibitors (PIs). For the validation set the correlation coefficients ranged from 0.76 (didanosine) to 0.96 (3TC) for NRTIs; 0.68 (EFV) to 0.81 (NVP) for NNRTIs; and 0.88 (amprenavir) to 0.95 (saquinavir) for PIs. For C sub-type predictions, with ANNs trained on sub-type B data, the correlation coefficient was 0.89. CONCLUSIONS: ANNs, based on the physiochemical properties of the PR and RT amino-acid sequences, predict phenotypic susceptibility to ARVs inhibiting these enzymes to an extent that is comparable to routine phenotypic susceptibility testing. These ANNs can also be used to predict resistance to C sub-types.

Microbial diversity of mid-stage Palinurid phyllosoma from Great Barrier Reef waters.

AIMS: This study aimed to determine the bacterial community associated with wild-caught, mid-stage larvae of spiny lobsters (Palinuridae) in their native oligotrophic marine environment, and to compare their diversity and composition with communities associated with aquaculture-reared larvae of the tropical rock lobster Panulirus ornatus. METHODS AND RESULTS: Bacterial clone libraries constructed from wild P. ornatus (two libraries) and Panulirus penicillatus (one library) larvae (phyllosoma) revealed a dominance of alpha-proteobacterial sequences, with Sulfitobacter spp.-affiliated sequences dominating both P. ornatus libraries and constituting a major portion of the P. penicillatus library. Vibrio-related sequences were rarely detected from wild phyllosoma clone libraries in contrast to similar studies of aquaculture-reared animals. Scanning electron microscopy analysis revealed low levels of bacterial colonization on the external carapace of wild phyllosoma, again in contrast to aquaculture-reared animals, which are often colonized with filamentous bacteria (mainly Thiothrix sp.) that compromise their health. Fluorescence in situ hybridization of sectioned wild phyllosoma tissue displayed low overall abundance of bacteria within the tissue and on external surfaces, with alpha-, beta-, and gamma-Proteobacteria being confirmed as members of this bacterial community. CONCLUSIONS: The consistency in predominant clone sequences retrieved from the three libraries indicated a conserved microbiota associated with wild phyllosoma. In addition, the observed differences in the microbial composition and load of reared and wild phyllosoma are indicative of the different environments in which the animals live. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacterial disease during early larval stages is a major constraint currently hindering the development of an aquaculture industry for the ornate rock lobster P. ornatus. Knowledge of the microbial community associated with wild animals will be advantageous for the identification of bacteria that may promote animal health.

Survival among motherless children in rural and urban areas in Guinea-Bissau.

AIM: With the increasing incidence of HIV and TB, motherless children are becoming a rapidly growing problem in Africa. However, few studies describe the survival patterns of these children. The aim of this study was to investigate the mortality of motherless children in urban and rural areas of Guinea-Bissau. METHODS: A historical cohort study was set up in urban and rural areas in Guinea-Bissau. Motherless children were selected from two study cohorts under demographic surveillance since 1990. The relatives of 128 motherless children from the rural cohort and 192 from the urban area, as well as a total of 807 controls, were examined and interviewed. RESULTS: Controlling for significant background factors revealed that motherless children had a markedly higher mortality than that of controls in both urban (mortality rate ratio (MR) 2.32 (95% confidence interval 1.11-4.84)) and rural areas (MR = 4.16 (2.79-6.22)). Virtually all the excess mortality occurred among children under 2 y of age when their mother died. Few motherless children had been provided with surrogate breastfeeding. CONCLUSIONS: Since nearly all children in Guinea are breastfed until 2 y of age, premature weaning may be one of the major causes of the higher mortality rates observed among motherless children.

Maternal mortality and access to obstetric services in West Africa.

OBJECTIVES: Process evaluation has become the mainstay of safe motherhood evaluation in developing countries, yet the extent to which indicators measuring access to obstetric services at the population level reflect levels of maternal mortality is uncertain. In this study we examine the association between population indicators of access to obstetric care and levels of maternal mortality in urban and rural West Africa. METHODS: In this ecological study we used data on maternal mortality and access to obstetric services from two population-based studies conducted in 16 sites in eight West African countries: the Maternal Mortality and Obstetric Care in West Africa (MAMOCWA) study in rural Sénégal, Guinea-Bissau and The Gambia and the Morbidité Maternelle en Afrique de l'Ouest (MOMA) study in urban Burkina Faso, Côte d'Ivoire, Mali, Mauritanie, Niger and Sénégal. RESULTS: In rural areas, maternal mortality, excluding early pregnancy deaths, was 601 per 100,000 live births, compared with 241 per 100,000 for urban areas [RR = 2.49 (CI 1.77-3.59)]. In urban areas, the vast majority of births took place in a health facility (83%) or with a skilled provider (69%), while 80% of the rural women gave birth at home without any skilled care. There was a relatively close link between levels of maternal mortality and the percentage of births with a skilled attendant (r = -0.65), in hospital (r = -0.54) or with a Caesarean section (r = -0.59), with marked clustering in urban and rural areas. Within urban or rural areas, none of the process indicators were associated with maternal mortality. CONCLUSION: Despite the limitations of this ecological study, there can be little doubt that the huge rural-urban differences in maternal mortality are due, at least in part, to differential access to high quality maternity care. Whether any of the indicators examined here will by themselves be good enough as a proxy for maternal mortality is doubtful however, as more than half of the variation in mortality remained unexplained by any one of them.

Factors associated with maternal mortality in rural Guinea-Bissau. A longitudinal population-based study.

OBJECTIVE: To assess demographic and obstetric risk factors for pregnancy-related death in a multiethnic rural population in a developing country. DESIGN: A prospective survey of women in the fertile age-range. SETTING: Rural Guinea-Bissau. POPULATION: More than 15,000 women living in 100 clusters were visited at six-monthly intervals over a period of more than six years. A total of 10,931 pregnancies were registered prospectively; 85 of these pregnancies resulted in maternal or late maternal death. MAIN OUTCOME MEASURE: Maternal mortality ratio. METHOD: In the rural areas of Guinea-Bissau, we conducted a prospective survey of women in the fertile age range. More than 15,000 women living in 100 clusters were visited at 6-monthly intervals over a period of more than six years. An analysis of demographic, environmental and obstetric risk factors for maternal death was performed based on 10,931 prospectively registered pregnancies; 85 of these pregnancies resulted in maternal or late maternal death. RESULTS: In the adjusted model maternal mortality ratio increased with increasing distance from the regional hospital (OR>25 km = 7.4 [95% CI: 1.6-132]). Multiple pregnancy was found to increase the risk of maternal death (OR = 3.4 [95% CI: 1.3-7.5]). The risk of subsequent maternal death was increased if the fetus was stillborn (OR = 5.3 [95% CI: 2.8-9.4]). Women living in the region of Gabu had higher mortality than those living in Biombo (OR = 2.5 [95% CI: 1.3-5.1]). No category of age or parity were associated with an increased risk of maternal mortality. Predictive values did not exceed 3% for any of the significant risk factors. CONCLUSIONS: For the purpose of reducing maternal mortality, the screening approach of antenatal care is of limited value. Age and parity should not be used routinely as selection criteria for transfer of otherwise healthy pregnant women to higher-level health institutions. Twin pregnancy seems to be the only operational risk factor identified in this study. Stillbirth is associated with an increased risk of maternal death. Regional differences must be studied further. The distance to emergency obstetric care (EOC) may determine the outcome of a complicated delivery.

Maternal mortality in Guinea-Bissau: the use of verbal autopsy in a multi-ethnic population.

BACKGROUND: In developing countries with scanty resources it is very important to have reliable data to establish priorities for the health sector; e.g. to reduce maternal mortality it is necessary to determine the most important causes. The majority of deaths, however, occur without previous contact with the health system and consequently conventional analyses of death certificates are not feasible. Instead, studies have been carried out in some developing countries with various forms of post-mortem interviews, the so-called verbal autopsies (VA). METHODS: We developed a structured interview with filter questions, which was applied to all deaths of women of fertile age in a cohort of 10,000 women living in 100 clusters in Guinea-Bissau and followed over a period of 6 years. The cause of death was ascertained by means of a series of diagnostic algorithms for the most common causes of maternal mortality, including postpartum haemorrhage, antepartum haemorrhage, puerperal infection, obstructed labour, eclampsia, abortion, and ectopic pregnancy. RESULTS: Of the 350 deaths of women of fertile age, 32% were maternal and it seems unlikely that a significant proportion of maternal deaths have not been classified correctly. Using the diagnostic algorithm 70% could be given a specific diagnosis, the most important causes being postpartum haemorrhage (42% [29/69]), obstructed labour (19% [13/69]), and puerperal infection (16% [11/69]). We attempted to identify the factors that are critical for obtaining sufficient information to reach a diagnosis. In the univariate analyses, it was important whether the respondent had been present during the last illness (P = 0.04) and whether the death occurred more than one week after delivery (P = 0.04). The husband was a better respondent than a co-wife (P = 0.08), and men in general provided more specific information than women (P = 0.08). Furthermore, information appeared to be better if the woman had died in the rainy season (P = 0.08). The length of the recall period, parity, age of woman, place of death, rural/urban residence, and ethnic group were not decisive. In the multivariate analysis sex and presence of respondent and time after delivery were significantly associated with the risk of not reaching a specific diagnosis. Women are less likely to provide adequate information for a diagnosis than men (odds ratio [OR] 3.1; 95% confidence interval [CI]: 1.2-8.1). Respondents that did not reside in the village during the departed woman's illness/delivery carried equal risk of not reaching a conclusion (OR 3.1; CI: 1.1-9.1). Deaths occurring more than one week after delivery were also less likely to be classified (OR 6.1; CI: 1.7-22.0). CONCLUSION: The VA described in the present paper left 30% of the maternal deaths unclassified without a specific diagnosis. Had all interviews been with husbands, only 14% would have remained unclassified. If we had only asked people who were present during the terminal phase of the victim's illness the proportion of classified deaths would have risen from 70% to 75%. It is likely that delayed maternal deaths have not been adequately covered by the present algorithms, but they may also simply be more difficult to describe due to the duration of the disease episode. In contrast to methods by which cause of death is established by a panel of medical experts, the present VA should be economically and technically viable in areas where health workers have only minimal training.

The role of vaginal secretory immunoglobulin A, Gardnerella vaginalis, anaerobes, and Chlamydia trachomatis in postabortal pelvic inflammatory disease.

In a prospective study of 129 women undergoing induced first-trimester abortion, 14 (10.9%) contracted postabortal pelvic inflammatory disease (PID). Samples of vaginal secretion for quantitation of secretory immunoglobulin A (sIgA) as well as isolates from cervix/urethra for the culture of anaerobes and aerobes, including Bacteroides fragilis et melaninogenicus and Gardnerella vaginalis, were obtained at the preoperative visit. Two blood samples from each woman with postabortal PID were analysed for antibodies against G. vaginalis. Twenty-five per cent of women with a history of PID developed postabortal PID, and 25% with vaginitis contracted postabortal infection (p less than 0.001 and p less than 0.005). Twenty-five per cent of women harboring C. trachomatis at the time of abortion developed infection. The presence of anaerobes or G. vaginalis was not associated with the frequency of postabortal PID (all p-values greater than 0.1). One woman with postabortal PID produced a culture positive for G. vaginalis and a rise in specific antibody titer. The levels of vaginal sIgA were not significantly associated with a positive history of PID (p greater than 0.6), with postabortal PID (p greater than 0.4) or with the presence of anaerobes or G. vaginalis at the time of abortion (p greater than 0.3). However, significantly elevated levels of sIgA were found in women harboring C. trachomatis (p less than 0.05). Thus, the study could not demonstrate any correlation between vaginal sIgA and PID, but increased sIgA in Chlamydia-positive women. A history of PID and vaginitis entailed a significant risk of contracting postabortal PID.

Lacrimal and salivary secretion in Sjögren's syndrome: the effect of systemic treatment with bromhexine.

In a randomized clinical study, 32 patients with Sjögrens syndrome (SS) were given placebo/bromhexine (Bisolvon) 48 mg daily for 3 weeks. Various ophthalmological and oral variables as well as different proteins in tear fluid and saliva were registered. Bromhexine stimulated the tear secretion significantly, presumably without changing the protein composition of the tear fluid. In saliva the IgM concentration in contrast to other proteins decreased in patients with high pre-treatment values. Bromhexine may be of valuable help in the treatment of some patients with SS.

Secretion rates of immunoglobulins, albumin, haptoglobin and complement factors C3 and C4 in the perfused jejunum and ileum of human Salmonella carriers.

Secretion rates of immunoglobulins and other proteins were assessed by luminal perfusion of jejunum and distal ileum, and the jejunal histology was evaluated in eight Danish chronic Salmonella typhi and paratyphi carriers compared to nine healthy controls who previously had suffered from typhoid or paratyphoid fever not followed by a carrier state. The median secretion rates for each protein investigated in the distal ileum as well as in the jejunum revealed no significant differences between the two groups. The secretion rate of secretory IgA was raised in both groups compared to previously investigated normal persons. The histological examination revealed no signs of inflammation or presence of bacteria. It was concluded that no primary humoral immune defect was revealed in the carriers.

Antigen-free diet in adult patients with atopic dermatitis. A double-blind controlled study.

The efficacy of an antigen-free diet on the activity of atopic dermatitis was examined in a double-blind study, comprising 33 adults with severe atopic dermatitis. The antigen-free diet (Vivasorb) was compared to a placebo diet during three weeks of hospitalization. Twenty-five patients were evaluable, two of whom had their diet stopped after a few days due to exacerbation. Nine patients improved, while 16 patients were unchanged. Among those who improved five patients had Vivasorb and four placebo diet. In the remaining group 11 patients had Vivasorb and five had placebo. Four patients reported of less pruritus, sleeplessness and antihistamine consumption (three Vivasorb, one placebo) while 21 did not (13 Vivasorb, eight placebo). Thus, there were no significant differences between the groups. Paraclinical studies of circulating eosinophilocytes, serum IgE, orosomucoid, HLA-antigens, and immunofluorescence of skin biopsies showed no differences between the Vivasorb and the placebo groups. The results from the examination of this relatively small number of patients suggest that elementary intolerance plays little role in the etiology of atopic dermatitis in adults.

Immunological studies in two children with recurrent parotitis.

In two children with recurrent parotitis, labial salivary gland biopsies showed chronic sialoadenitis. Immunofluorescence studies disclosed deposits of immunoglobulins and complement in juxta-acinar small vessels. Case 1 had gluten enteropathy, IgA deficiency and high titres of antinuclear antibodies (ANA), and in vivo fixation of ANA to nuclei of different cells in lip, skin and jejunum was present. Case 2 showed deposition of IgM in the dermo-epidermal junction of the skin. These findings suggest that autoimmune reactivity and immune complexes may play a role in the pathogenesis of this disorder.

Humoral and cellular immunity in typhoid and paratyphoid carrier state, investigated by means of quantitative immunoelectrophoresis and in vitro stimulation of blood lymphocytes.

The humoral and cellular immunity of 8 Salmonella carriers and 9 non-carriers was investigated and compared to findings in normal persons. The antibody response in serum and intestinal secretions was investigated by means of crossed immunoelectrophoresis, and blood lymphocytes were investigated by in vitro stimulation. Both carriers and non-carriers showed increased levels of precipitating antibodies as well as lymphocyte responses, when compared to normal persons. No differences in the antibody responses either qualitatively or quantitatively were found between carriers and non-carriers. Only few precipitins could be detected in intestinal secretions. Lymphocyte responses to S. typhi and S. paratyphi were significantly higher in carriers and non-carriers than in the controls. No significant difference in lymphocyte response to S. typhi, S. paratyphi and mitogens was obtained between carriers and non-carriers. Thus, the carrier state seems not due to detectable major immunodeficiency.

Secretion rate of intestinal immunoglobulins, complement factor C3, "acute phase" reactants, and albumin in the perfused ileum and jejunum of normal man.

A new method for assessment of the intestinal secretion rate of immunoglobulins and other proteins is evaluated. The procedure involves a combination of luminal perfusion of a defined intestinal segment and analysis of the aspirated perfusates by rocket immunoelectrophoresis. The technique is sensitive and reliable. A material from the normal human jejunum and ileum is presented. The method is proposed as an investigative tool for characterization of the local immunological system of the small intestine.

A double-blind controlled trial of elemental diet in severe, perennial asthma.

In a double-blind controlled trial 41 hospitalized adults with severe, perennial asthma of unknown aetiology were allocated to either an antigen-free elemental diet (Vivasorb) or control diet, i.e. blended ordinary hospital food, for 2 weeks. At the time of entry into the trial all patients were in an active but stable phase of the disease. Medical treatment was given throughout the study as clinically indicated. Peak expiratory flow was measured hourly during the daytime and patients noted their symptoms daily on an assessment form. Validation of variables according to a scoring system indicated that the elemental diet resulted in an improvement of the patients asthma (p less than 0.05). It is concluded that elemental diet may serve as a diagnostic tool for disclosing alimentary intolerance in patients with perennial asthma.

Disodium cromoglycate in the treatment of ulcerative colitis and Crohn's disease.

A controlled clinical study on disodium cromoglycate (DSCG) at a dose of 800 mg per day versus placebo was carried out in 141 patients with ulcerative colitis and 25 patients with Crohn's disease. Those of the ulcerative colitis patients who had been on sulphasalazine treatment continued that treatment during the trial (101 patients). Forty patients were intolerant of sulphasalazine. No patient received steroids during the last month before the study. Patients with Crohn's disease had their possible sulphasalazine treatment stopped before the trial. No beneficial effect of DSCG as compared with placebo was found, as the DSCG and the placebo group showed the same number of relapses in patients with a clinically inactive ulcerative colitis at the start of the trial and the same number of patients improving, deteriorating, and maintaining steady state in patients with clinically active ulcerative colitis at the start of the trial. There was no difference between relapse rate in DSCG and placebo groups in patients with Crohn's disease. No correlation between the eosinophil count in rectal mucosa and the outcome of the attack of ulcerative colitis could be demonstrated.