Factors Associated With Discontinuation of Tuberculosis Preventive Treatment: Post Hoc Analysis of 2 Randomized, Controlled Trials

BACKGROUND

Adherence to tuberculosis preventive treatment (TPT) is an important determinant of clinical benefit. We assessed the association of participant behaviors early in TPT with subsequent discontinuation.

METHODS

We used data from a phase 3 randomized trial and the preceding phase 2 trial to compare 4 months of rifampin to 9 months of isoniazid for TPT. We excluded participants whose providers discontinued TPT due to adverse events or tuberculosis disease. We analyzed 4 outcomes: discontinuing TPT within the first month of treatment, discontinuing TPT between the first and second month, discontinuing TPT after the second month, and completing treatment but not per protocol. We analyzed the association of outcomes with regimen and participant characteristics and 4 behavioral predictors of discontinuation recorded at the month 1 and month 2 follow-up visits: reporting symptoms of intolerance, missing >20% of doses, rescheduling appointments, and not bringing their medication bottle.

RESULTS

Overall, 6656 participants were included (phase 3, 5848; phase 2, 808), of whom 4318 (64.9%) completed treatment per protocol. Participant characteristics were inconsistently associated with discontinuation. Phase 3 trial participants with 1, 2, or 3-4 behavioral predictors at the month 1 follow-up had 5.0 (95% confidence interval, 3.6-6.7), 18.6 (13.3-26.1), and 79.4 (38.2-165.0), respectively, higher odds of discontinuing before the second month. The corresponding number of predictors at the month 2 follow-up had 1.8 (1.4-2.2), 4.7 (3.6-6.2), and 7.4 (4.6-11.9) higher odds of discontinuing before completing treatment; phase 2 findings were similar.

CONCLUSIONS

Four behavioral predictors recorded early in therapy were more strongly associated with subsequent discontinuation than participant characteristics, particularly when more than 1 behavioral predictor was recorded. Clinical Trials Registration. NCT00170209; NCT00931736.

Longitudinal antibody and T cell responses in Ebola virus disease survivors and contacts: an observational cohort study

BACKGROUND

The 2013-16 Ebola virus disease epidemic in west Africa caused international alarm due to its rapid and extensive spread resulting in a significant death toll and social unrest within the affected region. The large number of cases provided an opportunity to study the long-term kinetics of Zaire ebolavirus-specific immune response of survivors in addition to known contacts of those infected with the virus.

METHODS

In this observational cohort study, we worked with leaders of Ebola virus disease survivor associations in two regions of Guinea, Guéckédou and Coyah, to recruit survivors of Ebola virus disease, contacts from households of individuals known to have had Ebola virus disease, and individuals who were not knowingly associated with infected individuals or had not had Ebola virus disease symptoms to serve as negative controls. We did Zaire ebolavirus glycoprotein-specific T cell analysis on peripheral blood mononuclear cells (PBMCs) on location in Guinea and transported plasma and PBMCs back to Europe for antibody quantification by ELISA, functional neutralising antibody analysis using live Zaire ebolavirus, and T cell phenotype studies. We report on the longitudinal cellular and humoral response among Ebola virus disease survivors and highlight potentially paucisymptomatic infection.

FINDINGS

We recruited 117 survivors of Ebola virus disease, 66 contacts, and 23 negative controls. The mean neutralising antibody titre among the Ebola virus disease survivors 3-14 months after infection was 1/174 (95% CI 1/136-1/223). Individual results varied greatly from 1/10 to more than 1/1000 but were on average ten times greater than that induced after 1 month by single dose Ebola virus vaccines. Following reactivation with glycoprotein peptide, the mean T cell responses among 116 Ebola virus disease survivors as measured by ELISpot was 305 spot-forming units (95% CI 257-353). The dominant CD8+ polyfunctional T cell phenotype, as measured among 53 Ebola virus disease survivors, was interferon γ+, tumour necrosis factor+, interleukin-2-, and the mean response was 0·046% of total CD8+ T cells (95% CI 0·021-0·071). Additionally, both neutralising antibody and T cell responses were detected in six (9%) of 66 Ebola virus disease contacts. We also noted that four (3%) of 117 individuals with Ebola virus disease infections did not have circulating Ebola virus-specific antibodies 3 months after infection.

INTERPRETATION

The continuous high titre of neutralising antibodies and increased T cell response might support the concept of long-term protective immunity in survivors. The existence of antibody and T cell responses in contacts of individuals with Ebola virus disease adds further evidence to the existence of sub-clinical Ebola virus infection.

FUNDING

US Food & Drug Administration, Horizon 2020 EU EVIDENT, Wellcome, UK Department for International Development.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

[Upperurinary Tract Diversion With JJ Stent By Endoscopy : Indications, Results And Morbidity]

OBJECTIVE

to report the indications and the results of the upper urinary tract by endoscopic route by a double J probe in our Center.

PATIENTS AND METHODS

This was a retrospective mono-centric descriptive study from January 1st 2018 to June 30th 2019 including all patients that had a JJ stent as a type of upperurinary tract diversion.

RESULTS

seventy four patients were included. The average age of patients was 43.6 ± 17.5 years. The sex-ratio was 0.6. The obstructive renal colic was the most common operative indication in 62.1% (46) of patients. The etiologies were dominated by urolithiasis with 39.1% (29) of patients. Anesthesia was general in 67.5% (50) and locoregional in 32.5% of patients (24). The procedure was performed without fluoroscopic control (blind) in 66.2% of cases(49), therewere 89.7% case of success (44 patients). The success rate was 86.5% (64) patients and the failure rate 13.5% (10) of patients. Five (6.7%) patients had a postoperative acute pyelonephritis complication requiringremoval of the JJ stent.

CONCLUSION

The rise of the double J probe made possible to prepare the ureter, thus facilitating the endoscopic treatment of urinary lithiasis. The complication rate observed in our patients was low. The compliance with the rules of asepsis could reduce these complications.

Four Months of Rifampin or Nine Months of Isoniazid for Latent Tuberculosis in Adults

BACKGROUND

A 9-month regimen of isoniazid can prevent active tuberculosis in persons with latent tuberculosis infection. However, the regimen has been associated with poor adherence rates and with toxic effects.

METHODS

In an open-label trial conducted in nine countries, we randomly assigned adults with latent tuberculosis infection to receive treatment with a 4-month regimen of rifampin or a 9-month regimen of isoniazid for the prevention of confirmed active tuberculosis within 28 months after randomization. Noninferiority and potential superiority were assessed. Secondary outcomes included clinically diagnosed active tuberculosis, adverse events of grades 3 to 5, and completion of the treatment regimen. Outcomes were adjudicated by independent review panels.

RESULTS

Among the 3443 patients in the rifampin group, confirmed active tuberculosis developed in 4 and clinically diagnosed active tuberculosis developed in 4 during 7732 person-years of follow-up, as compared with 4 and 5 patients, respectively, among 3416 patients in the isoniazid group during 7652 person-years of follow-up. The rate differences (rifampin minus isoniazid) were less than 0.01 cases per 100 person-years (95% confidence interval [CI], -0.14 to 0.16) for confirmed active tuberculosis and less than 0.01 cases per 100 person-years (95% CI, -0.23 to 0.22) for confirmed or clinically diagnosed tuberculosis. The upper boundaries of the 95% confidence interval for the rate differences of the confirmed cases and for the confirmed or clinically diagnosed cases of tuberculosis were less than the prespecified noninferiority margin of 0.75 percentage points in cumulative incidence; the rifampin regimen was not superior to the isoniazid regimen. The difference in the treatment-completion rates was 15.1 percentage points (95% CI, 12.7 to 17.4). The rate differences for adverse events of grade 3 to 5 occurring within 146 days (120% of the 4-month planned duration of the rifampin regimen) were -1.1 percentage points (95% CI, -1.9 to -0.4) for all events and -1.2 percentage points (95% CI, -1.7 to -0.7) for hepatotoxic events.

CONCLUSIONS

The 4-month regimen of rifampin was not inferior to the 9-month regimen of isoniazid for the prevention of active tuberculosis and was associated with a higher rate of treatment completion and better safety. (Funded by the Canadian Institutes of Health Research and the Australian National Health and Medical Research Council; ClinicalTrials.gov number, NCT00931736 .).

Safety and Side Effects of Rifampin versus Isoniazid in Children

BACKGROUND

The treatment of latent infection with Mycobacterium tuberculosis is important in children because of their vulnerability to life-threatening forms of tuberculosis disease. The current standard treatment - 9 months of isoniazid - has been associated with poor adherence and toxic effects, which have hampered the effectiveness of the drug. In adults, treatment with 4 months of rifampin has been shown to be safer and to have higher completion rates than 9 months of isoniazid.

METHODS

In this multicenter, open-label trial, we randomly assigned 844 children (<18 years of age) with latent M. tuberculosis infection to receive either 4 months of rifampin or 9 months of isoniazid. The primary outcome was adverse events of grade 1 to 5 that resulted in the permanent discontinuation of a trial drug. Secondary outcomes were treatment adherence, side-effect profile, and efficacy. Independent review panels whose members were unaware of trial-group assignments adjudicated all adverse events and progression to active tuberculosis.

RESULTS

Of the children who underwent randomization, 829 were eligible for inclusion in the modified intention-to-treat analysis. A total of 360 of 422 children (85.3%) in the rifampin group completed per-protocol therapy, as compared with 311 of 407 (76.4%) in the isoniazid group (adjusted difference in the rates of treatment completion, 13.4 percentage points; 95% confidence interval [CI], 7.5 to 19.3). There were no significant between-group differences in the rates of adverse events, with fewer than 5% of the children in the combined groups with grade 1 or 2 adverse events that were deemed to be possibly related to a trial drug. Active tuberculosis, including 1 case with resistance to isoniazid, was diagnosed in 2 children in the isoniazid group during 542 person-years of follow-up, as compared with no cases in the rifampin group during 562 person-years (rate difference, -0.37 cases per 100 person-years; 95% CI, -0.88 to 0.14).

CONCLUSIONS

Among children under the age of 18 years, treatment with 4 months of rifampin had similar rates of safety and efficacy but a better rate of adherence than 9 months of treatment with isoniazid. (Funded by the Canadian Institutes of Health Research and Conselho Nacional de Pesquisa; ClinicalTrials.gov number, NCT00170209 .).

[Results of anastomotic urethroplasty for male urethral stricture disease]

OBJECTIVE

To report our experience with anastomotic uretroplasty (AU) due to male urethral stricture disease (USD) and to identify factors affecting the results.

PATIENTS AND METHODS

We conducted a retrospective study over a period of 4 years and 6 months (July 2012 to December 2016). Any subsequent use of endoscopic urethrotomy or new urethroplasty was considered a failure.

RESULTS

Forty-eight cases were included. The mean age of patients was 53.5±17.3 years (23-87 years). Urinary retention was the reason for consultation in 42 cases (87.5%). The most common localization of USD was the bulbar urethra (n=45). The mean length of USD was 1.23±0.62cm (0.5-3cm) with a median length of 1cm. The etiology was post-infectious in 56.3% of cases. More than half (58.3%) of patients had already undergone at least one urethral manipulation. After an average follow-up of 21.1±12.6 months (1 to 52 months), the overall success rate was 77.1%. In univariate analysis, length, cause and location of the stricture, age of patient, the presenting symptoms of the stricture, previous urethral manipulation and surgeon experience did not significantly impact on the success rate of anastomotic urethroplasty at one and two years follow-up.

CONCLUSION

The AU had provided good results in our practice. The infectious origin of the stricture and previous urethral manipulation did not significantly impact the result of this surgical technique.

LEVEL OF EVIDENCE

4.

[Fatal female genital mutilation in a 10-year-old girl]

Female genital mutilation (FGM) comprises all procedures involving partial or total removal of the external genitalia and/or any other procedures affecting the female genitalia, for cultural or religious reasons or for nontherapeutic purposes in general. FGM is responsible for a number of short-, medium-, and long-term complications that can engage the vital and functional prognosis, especially in African countries. We report on a case in a 10-year-old girl who underwent genital mutilation, a traditional type of total excision during the neonatal period. She was followed for urethral meatus stenosis, which then was complicated by obstructive chronic kidney failure and urinary sepsis, whose progression was fatal.

First insights into circulating Mycobacterium tuberculosis complex lineages and drug resistance in Guinea

•

First insight into resistance levels and genetic diversity of TB in Guinea.

•

Rapid expansion of drug-resistance prone LAM10 Cameroon family.

•

Population structure reveals less ‘ancestral’ TB than in surrounding countries.

•

Knowledge of genetic diversity is relevant for tuberculosis control programs.

In this study we assessed first-line anti-tuberculosis drug resistance and the genotypic distribution of Mycobacterium tuberculosis complex (MTBC) isolates that had been collected from consecutive new tuberculosis patients enrolled in two clinical trials conducted in Guinea between 2005 and 2010. Among the total 359 MTBC strains that were analyzed in this study, 22.8% were resistant to at least one of the first line anti-tuberculosis drugs, including 2.5% multidrug resistance and 17.5% isoniazid resistance, with or without other drugs. In addition, further characterization of isolates from a subset of the two trials (n = 184) revealed a total of 80 different spoligotype patterns, 29 “orphan” and 51 shared patterns. We identified the six major MTBC lineages of human relevance, with predominance of the Euro-American lineage. In total, 132 (71.7%) of the strains were genotypically clustered, and further analysis (using the DESTUS model) suggesting significantly faster spread of LAM10_CAM family (p = 0.00016). In conclusion, our findings provide a first insight into drug resistance and the population structure of the MTBC in Guinea, with relevance for public health scientists in tuberculosis control programs.

Shifts in Mycobacterial Populations and Emerging Drug-Resistance in West and Central Africa

In this study, we retrospectively analysed a total of 605 clinical isolates from six West or Central African countries (Benin, Cameroon, Central African Republic, Guinea-Conakry, Niger and Senegal). Besides spoligotyping to assign isolates to ancient and modern mycobacterial lineages, we conducted phenotypic drug-susceptibility-testing for each isolate for the four first-line drugs. We showed that phylogenetically modern Mycobacterium tuberculosis strains are more likely associated with drug resistance than ancient strains and predict that the currently ongoing replacement of the endemic ancient by a modern mycobacterial population in West/Central Africa might result in increased drug resistance in the sub-region.

Mapping of a novel susceptibility locus suggests a role for MC3R and CTSZ in human tuberculosis

RATIONALE

Tuberculosis remains a major cause of morbidity and mortality in the developing world. A better understanding of the mechanisms of disease protection could allow novel strategies to disease management and control.

OBJECTIVES

To identify human genomic loci with evidence of linkage to tuberculosis susceptibility and, within these loci, to identify individual genes influencing tuberculosis susceptibility.

METHODS

Affected sibling pair analysis in South African and Malawian populations. Independent case-control study in West Africa.

MEASUREMENTS AND MAIN RESULTS

Two novel putative loci for tuberculosis susceptibility are identified: chromosome 6p21-q23 and chromosome 20q13.31-33--the latter with the strongest evidence for any locus reported to date in human tuberculosis (single point LOD score of 3.1, P = 10(-4), with a maximum likelihood score [MLS] of 2.8). An independent, multistage genetic association study in West African populations mapped this latter region in detail, finding evidence that variation in the melanocortin 3 receptor (MC3R) and cathepsin Z (CTSZ) genes play a role in the pathogenesis of tuberculosis.

CONCLUSIONS

These results demonstrate how a genomewide approach to the complex phenotype of human tuberculosis can identify novel targets for further research.

Prevalence of symptoms of asthma, rhinitis and eczema in 13- to 14-year-old children in Africa: the International Study of Asthma and Allergies in Childhood Phase III

Phase I of the International Study of Asthma and Allergies in Childhood has provided valuable information regarding international prevalence patterns and potential risk factors in the development of asthma, allergic rhinoconjunctivitis and eczema. However, in Phase I, only six African countries were involved (Algeria, Tunisia, Morocco, Kenya, South Africa and Ethiopia). Phase III, conducted 5-6 years later, enrolled 22 centres in 16 countries including the majority of the centres involved in Phase I and new centres in Morocco, Tunisia, Democratic Republic of Congo, Togo, Sudan, Cameroon, Gabon, Reunion Island and South Africa. There were considerable variations between the various centres of Africa in the prevalence of the main symptoms of the three conditions: wheeze (4.0-21.5%), allergic rhinoconjunctivitis (7.2-27.3%) and eczema (4.7-23.0%). There was a large variation both between countries and between centres in the same country. Several centres, including Cape Town (20.3%), Polokwane (18.0%), Reunion Island (21.5%), Brazzaville (19.9%), Nairobi (18.0%), Urban Ivory Coast (19.3%) and Conakry (18.6%) showed relatively high asthma symptom prevalences, similar to those in western Europe. There were also a number of centres showing high symptom prevalences for allergic rhinoconjunctivitis (Cape Town, Reunion Island, Brazzaville, Eldoret, Urban Ivory Coast, Conakry, Casablanca, Wilays of Algiers, Sousse and Eldoret) and eczema (Brazzaville, Eldoret, Addis Ababa, Urban Ivory Coast, Conakry, Marrakech and Casablanca).

Treatment outcome of asthma after one year follow-up in health centres of several developing countries

SETTING

Seven selected out-patient clinics caring for asthma patients in Algeria, Guinea, Morocco, Syria, Turkey and Vietnam.

DESIGN

Evaluation of treatment outcomes after one year of follow-up of a cohort of asthma patients consecutively enrolled in a prospective study evaluating routine practice.

RESULTS

Among 310 asthma patients registered, the following outcomes were recorded after one year of follow-up: 95 (31%) successful, 61 (20%) under control, 35 (11%) failed, 116 (37%) defaulted and 3 (1%) transferred. Among the 167 (53.9%) patients still on treatment after one year there was a substantial increase in the proportion of patients classified as intermittent at the end of treatment (from 11% to 53%), with a decrease in all categories of persistent asthma (from 34% to 12% for mild, 45% to 28% for moderate and 10% to 8% for severe asthma).

CONCLUSIONS

While patients' quality of life can be improved if they follow regular treatment, the key challenge in providing care is to ensure that patients adhere to their treatment.

Polymorphism within the interferon-gamma/receptor complex is associated with pulmonary tuberculosis

RATIONALE

Interferon-gamma (IFN-gamma) is of central interest in the study of tuberculosis. A number of single-gene mutations have been identified in the IFN-gamma signaling pathway that predispose to severe mycobacterial disease, but the relevance of polymorphism within these genes to the common phenotype of tuberculosis remains unclear.

METHODS

A total of 1,301 individuals were included in a large, detailed study of West African populations with pulmonary tuberculosis. We investigated disease association with the genes encoding IFN-gamma and its receptor subunits (IFNG, IFNGR1, and IFNGR2).

RESULTS

Within the IFNG gene, two promoter variants showed evidence of novel disease association: -1616GG (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.11-2.00; p = 0.008) and +3234TT (OR, 1.40; 95% CI, 1.09-1.80; p = 0.009). The +874AA genotype was not significantly more frequent among cases over control subjects (OR, 1.16; 95%CI, 0.89-1.51; p = 0.25). In addition, novel disease association was also found with the -56CC genotype of the IFNGR1 promoter (OR, 0.75; 95% CI, 0.57-0.99; p = 0.041). No disease association was seen with the IFNGR2 locus.

CONCLUSIONS

These results provide evidence of a significant role for genetic variation at the IFNG locus and provide detailed understanding of the genetic mechanisms underlying this association. The disease association with IFNGR1 is novel, and together these findings support the hypothesis that genetically determined variation in both IFN-gamma production and responsiveness influences the risk of developing tuberculosis.

Benefit of amoxicillin in differentiating between TB suspects whose initial AFB sputum smears are negative

SETTING

Out-patient dispensary in Conakry, Guinea, West Africa.

OBJECTIVE

To differentiate between pulmonary tuberculosis (PTB) and non-PTB diseases among 204 acid-fast bacilli (AFB) smear-negative adult TB suspects.

DESIGN

We derived scores from clinical, serological and radiological findings among PTB suspects aged > or = 15 years who, after having had three AFB-negative smears, were treated for 10 days with amoxicillin (AMX, 1.5 g/day).

RESULTS

At the selected cut-off score from model 1 (clinical), sensitivity for PTB was 95%, specificity 40%, negative predictive value (NPV) 84%, and positive predictive value (PPV) 69%. Comparable values from model 2 (clinical + serological + radiological) were: sensitivity 99%, specificity 45%, NPV 97%, and PPV 71%. Results from AMX were better: sensitivity 92%, specificity 93%, NPV 94%, and PPV 91%. Of the 117 suspects who failed to respond clinically and radiographically to AMX and remained AFB smear-negative, 110 (94%) had PTB, confirmed either by positive culture (73 patients) or response to anti-tuberculosis treatment (37 patients).

CONCLUSION

The clinical and radiographic response to AMX is better than derived scores at differentiating between PTB and non-PTB in TB suspects presenting to a dispensary in Guinea, a low HIV-seroprevalence country.

Implementation of asthma guidelines in health centres of several developing countries

SETTING

Nine selected out-patient clinics caring for asthma patients in Algeria, Guinea, Ivory Coast, Kenya, Mali, Morocco, Syria, Turkey and Vietnam.

DESIGN

Prospective enrolment of consecutive patients considered by the practitioner to have asthma with evaluation of adherence of the practitioner with recommended standard case management, including proportion of patients confirmed to have asthma, proportion in whom severity was correctly graded and proportion in whom treatment with inhaled corticosteroids corresponded to severity grade.

RESULTS

Of 499 consecutive patients, 456 (91%) were enrolled and evaluated. The diagnosis was confirmed in 263 (58%). Agreement between the practitioner and the guidelines in assigning grade of severity was moderate overall (kappa = 0.42). It was higher for assignment of grade using symptoms (K = 0.51), but poor for assignment of grade using peak expiratory flow (PEF) rate (kappa = 0.29), with practitioners tending to underestimate the severity. Agreement between the practitioners' assessment of severity and treatment with inhaled corticosteroids was poor (kappa = 0.18), with underutilisation of inhaled corticosteroids.

CONCLUSIONS

Practitioners caring for asthma patients in this study tended to underutilise the PEF rate in assessing their patients and underutilised treatment of patients with inhaled corticosteroids.

[Prevalence and morbidity of G6PD deficiency in sickle cell disease in the homozygote]

Sickle cell disease and G6PD deficiency have similar prevalence of 8 to 10% in Senegalese population. Our objectives were to determine the prevalence of G6PD deficiency in Hb S carriers and normal subjects, and to assess the interaction of G6PD deficiency on clinical severity of sickle cell disease. G6PD activity was measured in 319 sickle cell patients and in 318 subjects without HbS. Clinical severity was compared in male homozygous sickle cell patients (11 with G6PD deficiency and 19 without deficit). In homozygous sickle cell patients, the G6PD status was assessed after correction of reticulocyte count following the micro-centrifugation method of Herz. We found that prevalence of G6PD deficiency was higher in sickle cell disease patients (21.6 %) than in normal subjects (12.3 %) (p = 0.001). No difference was found in the two groups of male sickle cell disease patients concerning number of vaso-occlusive crisis, number of transfusion, frequency of infectious episodes, number of chronic complications, disturbances on patient's activity and total index severity.

Useful clues to the presence of smear-negative pulmonary tuberculosis in a West African city

OBJECTIVE

Tuberculosis suspects with negative sputum smears for acid-fast bacilli (AFB) may have either pulmonary tuberculosis (PTB) or some other pulmonary disease (non-PTB). The aim of this study was to improve the differentiation between PTB and non-PTB.

DESIGN

We enrolled 396 tuberculosis suspects 15 years of age or older who had cough of 21 days or longer and three negative AFB smears. Non-PTB was diagnosed by clinical and radiographic responses to amoxicillin; smear-negative PTB was diagnosed by positive culture for Mycobacterium tuberculosis or response to antituberculosis chemotherapy.

RESULTS

Multivariate analysis, without X-ray variables, of 79 patients with a final diagnosis of non-PTB and 110 patients with smear-negative PTB indicated that age less than 37 years, family contact with TB, never having been married, loss of weight, lack of expectoration, human immunodeficiency virus (HIV) seropositivity, and tuberculin reactivity were significantly associated with PTB. When the initial X-ray findings were included, age younger than 37 years, lack of expectoration, HIV seropositivity, and tuberculin reactivity remained in the model, and cavitation and patchy densities were significantly associated.

CONCLUSION

The response to 10 days of amoxicillin and certain demographic, clinical and radiographic characteristics are useful in separating non-PTB from PTB in tuberculosis suspects with negative AFB smears.

Fine mapping of a putative tuberculosis-susceptibility locus on chromosome 15q11-13 in African families

Host genetics plays an important role in individual susceptibility and resistance to infectious diseases, but no genes have yet been identified using genome-wide screens. Twin studies have indicated that tuberculosis susceptibility has a significant host genetic component, and several genes appear to be involved. Recently, a genome-wide linkage analysis of 136 African families identified chromosome 15q11-13 as a region with suggestive evidence of linkage, with a LOD score of 2.0. We tested 10 microsatellite markers and 5 positional candidate genes in this chromosomal region for deviation from random transmission from parents to affected offspring. The polymorphisms, lying in a region of 14 cM, were initially typed in the same 79 Gambian families used in the genome screen. A borderline significant association with a 7 bp deletion in UBE3A (P = 0.01) was found. This polymorphism was then evaluated further in a larger series of families with tuberculosis, including 44 Guinean families and 57 families from South Africa. Testing for association between the deletion and tuberculosis across all the families using the exact symmetry test further supported the association (overall P = 0.002). These fine-mapping data suggest that UBE3A or a closely flanking gene may be a tuberculosis-susceptibility locus.

[Place and resistance of epidemic strains of Shigella dysenteriae-1 isolated at the Fann Hospital from 1995 to 1999]

Shigella dysenteriae-1 (S.d-1) takes a more and more important place in intertropical countries, with multiresistant strains to antibiotics. the objectives of the study is to determine the prevalence of S.d-1 among bacterial isolations at Fann Hospital at Dakar, and to identify the resistant profiles of the strains. This retrospective study was conducted on the strains isolated between 1995 and 1999 by examination of faeces for bacterial pathogens. the susceptibility of the strains to antibiotics was studied by disc diffusion test with Mueller Hinton agar, and detection of extended broad spectrum beta-lactamase. Shigella dysenteriae-1 represented 45.18 % of Shigella strains and was particularly isolated in winter season (from August to September), more frequently in men (sex ratio: 2 / 1). Among the strains, 72 % were resistant to beta-lactams, and the ratio of multiresistant strains represented 42 %, concerning cotrimoxazol, chloramphenicol, tetracyclin and aminopenicillins. Only one strain produced extended broad spectrum beta-lactamase. Quinolons were the most active antibiotics but have to be used rationally.

Allelic association between the NRAMP1 gene and susceptibility to tuberculosis in Guinea-Conakry

Forty four families from Guinea-Conakry were analysed to test for association between NRAMP1 (Natural Resistance Associated Macrophage Protein 1) polymorphisms and tuberculosis. Each family included at least one affected sib and one parent. Healthy sibs were also analysed and on average the families included four members. A total of 160 individuals were included in the final dataset. The analysis of association was performed using an extended TDT test, TRANSMlT, to allow for missing information in the parental genotypes. Three polymorphisms in the NRAMP1 gene were typed: a microsatellite (CA) repeat, a 4 bp deletion in the 3' untranslated region and a single nucleotide change in intron 4. The single base change in intron 4 was significantly associated (p = 0.036) with tuberculosis. Our results therefore confirm, using a family-based approach on a newly studied population, the previously reported association between this polymorphism and tuberculosis in a population-based study of West Africans.

Affordability of inhaled corticosteroids as a potential barrier to treatment of asthma in some developing countries

SETTING

The cost and availability of the medications required for the treatment of asthma may represent potential barriers to effective management.

METHOD

A survey of prices and policies for components of asthma treatment in 1998, in Algeria, Burkina Faso, Ivory Coast, Guinea, Mali, Syria, Turkey and Vietnam.

RESULTS

Medications were consistently available in only four of the eight countries studied. The cost of essential medications for standard case management varied by over five times for beclomethasone and by over three times for inhaled salbutamol. In all but two countries, the cost of one year of drugs for treatment of a moderate, persistent case exceeded the monthly salary of a nurse in that country. The essential drugs list included inhaled salbutamol in five of eight countries and beclomethasone in three of eight. The costs of medications were lower where generic preparations were available and, to a lesser extent, where the medications are on the essential drugs list.

CONCLUSIONS

The cost and availability of medications vary widely, and may represent an important barrier to effective management in some low and middle income countries.

Community acquired pneumonia in adults: a study comparing clinical features and outcome in Africa (Republic of Guinea) and Europe (France)

BACKGROUND

Community acquired pneumonia is the most common cause of death from infectious disease both in western and developing countries. A study was carried out in Conakry, Republic of Guinea and Tours, France in order to compare signs, symptoms, severity of illness, risk factors, and clinical outcome of community acquired pneumonia in adult patients admitted to hospital.

METHODS

The study was performed in the cities of Conakry and Tours over the same one year period. Patients with nosocomial pneumonia, tuberculosis, and those who were HIV positive were excluded. Data were recorded on the same forms in both centres. A severity score was calculated according to American Thoracic Society criteria. Follow up was evaluated at days 2, 7 and 15.

RESULTS

A total of 333 patients (218 from Conakry, 115 from Tours) were included in the study with a diagnosis of community acquired pneumonia, with or without lung abscess or pleural effusion. Mean age was higher and pre-existing illness rate, dehydration, agitation, and stupor were more frequent in patients in Tours. Respiration rates of > 30 breaths/min and the incidence of crackles were identical in the two centres. Fever above 39 degrees C, initial shock, chest pain, and herpes were significantly more frequent in Conakry. Initial chest radiographic abnormalities were similar in the two groups, ranging from unilateral pleuropulmonary involvement (89% and 83% in Conakry and Tours, respectively) to diffuse patchy parenchymal disease. Parapneumonic effusion was present in 17% and 16% of the patients of Conakry and Tours, respectively. Pneumonia was considered to be severe in 33% and 42% of the patients, respectively. In Conakry first line antibiotic therapy was penicillin alone (2 million units a day) for 197 patients (90%) and second line antibiotic therapy was prescribed for 25 patients (12%). In Tours first line therapy consisted of a single antibiotic (amoxicillin, third generation cephalosporins) for 65 patients (57%) and second line antibiotic therapy was prescribed for 55 patients (48%). The clinical outcome was similar in Conakry and Tours: 88% and 85% of patients, respectively, were afebrile or clinically cured at day 15. The mortality rate was similar (6% and 8%, respectively).

CONCLUSIONS

The problems encountered in the management of community acquired pneumonia are quite different in western and developing countries. This study shows that low doses of penicillin can cure 90% of African patients with pneumonia as effectively as more aggregative treatments in European patients who are both older and have greater comorbidity. Although pneumococci with reduced penicillin sensitivity occur in western countries, this does not seem to be the case in black Africa. For these reasons, low doses of penicillin or amoxicillin remain good first line treatment.

Acute respiratory infections in children: a community-based study comparing a primary health center and a pediatric unit, Republic of Guinea

OBJECTIVE

A community-based study was carried out in the Republic of Guinea in order to evaluate the frequency of occurrence, severity of illness, risk factors and the results of planned treatment of acute respiratory infections (ARI) in children under the age of 15 years.

DESIGN

The study was performed over a 1-year period in 2 distinct areas, 1 rural and 1 urban. A total of 2622 ARI were identified among children under 15 years of age. In the rural area, data were collected by primary health-care workers and by 2 physicians who were trained to supervise the study.

RESULTS

Among the rural population, 1422 ARI were identified. In the city center, Conakry, 1200 ARI were identified in one children's hospital. The child population under 5 years of age was significantly greater in the rural area (95.2%) than in the city center (83.2%) (P < 0.0001). Malnutrition affected 10.6% of all the children. There were discrepancies in symptoms and signs affecting the 2 groups but the severity scores, including children under 5 years of age, were not significantly different: including children under 5 years of age, were not significantly different: 10-11% of the children were considered to have severe disease and 6.2% required urgent referral to hospital. Upper and lower respiratory infections (URI and LRI) were equally represented (49.9% and 50.1% respectively). Distribution of each type of ARI was significantly different in the 2 groups: there were significantly more URI in the city center, especially tonsillitis. Bronchitis and bronchopneumonia occurred significantly more often in the rural area. Pneumonia and bronchopneumonia represented 9.8% of all ARI. Use of antibiotic therapy was known in 2557 patients: 1268 URI and 1289 LRI. In children with URI, 69.7% did not receive antibiotic therapy, 29.9% received 1 antibiotic and 0.03% received 2 antibiotics successively. Children from the city center received significantly more antibiotics than in the rural health center. In children with LRI, 17.8% did not receive antibiotic therapy, 81.7% received 1 antibiotic and 0.05% received 2 antibiotics successively. There was no significant difference between the 2 centers in antibiotic prescription. Clinical outcome showed that 93% of children were considered to be cured at day 7 and 99.4% at day 14. 14 children with severe pneumonia died. The infection cost (antibiotics plus other drugs prescribed as supportive care) was 0.45 US$ per child in the rural area and 9.7 US$ in the children's hospital.

CONCLUSION

This supervised study constitutes the first large longitudinal study concerning respiratory infections in West Africa. It demonstrates that simple guidelines are valid in order to prevent mortality and complications. Care appropriate to population requirements in term of infectious diseases can be delivered with low cost and low technology.

The prevalence of diabetes mellitus in three population groups in the Republic of Mali

Three different adult population groups in Mali were screened for diabetes mellitus by means of a post-prandial blood glucose determination. The prevalence of diabetes for the entire population sampled was found to be 1-4%. Diabetes mellitus was strongly suspected in an additional 8-4%. The prevalence of elevated post-prandial blood glucose levels was found to be the lowest (5-1%) among a group of Bambara farmers who live an active rural life and whose total daily caloric intake is less than 1,000 on the average, only half of it provided by carbohydrates.

Leishmanin skin sensitivity in the inland delta of the Niger

Leishmanin skin tests were applied to 266 subjects in the city of Mopti which is located on several islands in the center of the inland delta of the Niger in the Republic of Mali. The antigen employed contains 6-10 million killed leptomonads per ml in a sterile suspension preserved with 1:10,000 thiomersal and unlike the phenol suspended antigens, does not give false positive tests. Of the 249 subjects who completed the study 12 (4.8%) had positive reactions, the lowest positive reaction rate yet observed in Mali. No false positive reactions occurred among 139 subjects tested with a control solution of 1:10,000 thiomersal. The absence of known cases of cutaneous leishmaniasis in Mopti's permanent population and the absence of suitable vectors within the city would indicate that positive reactors reflect previous L. tropica infections acquired in the surrounding rural areas where the disease is known to exist or else previous infection with non-pathogenic mammalian or reptilian species of Leishmania.