[Sensitization to Blomia tropicalis among asthmatic patients in Yaoundé, Cameroon]. / Sensibilisation à Blomia tropicalis chez les patients asthmatiques à Yaoundé, Cameroun.

INTRODUCTION: The aim of this study was to determine the prevalence and investigate associated factors for Blomia tropicalis (BT) sensitization in adolescent and adult patients with asthma in Yaoundé (Cameroon). METHODS: We performed a cross-sectional study of 18 months duration (January 2012 to June 2013). All asthmatic patients who were seen for a consultation during the study period and who had a skin prick testing for perennial aeroallergens were included in the study. RESULTS: Two hundred and one asthmatic patients (132 female patients, 65.7%) with median age (1st-3rd quartiles) of 35 (20-51.5) years were included in the study. Ninety-six (47.8%) patients had positive skin tests to BT. BT sensitization was associated with sensitization to two other dust mites (Dermatophagoides pteronyssinus [DP] and Dermatophagoides farinae [DF]) in 75 (86.2%) patients. The only clinical factor associated with BT sensitization was the presence of persistent rhinitis (odds ratio [confidence interval 95%]: 2.06 [1.12-3.81]). The independent allergenic factors associated with BT sensitization were sensitization to DP (3.49 [CI 95%: 1.49-8.19]), to DF (4.88 [CI 95%: 2.10-11.36]) and to German cockroach (4.16 [CI 95%: 1.72-10.09]). CONCLUSION: Blomia tropicalis sensitization is common in asthmatic patients in Yaoundé. It occurs most often in the context of sensitization to multiple aeroallergens, particularly with sensitization to other dust mites and German cockroach.

Correlates of cigarette smoking among university students in Cameroon.

OBJECTIVE: To determine factors associated with smoking among university students in Cameroon. DESIGN: A cross-sectional survey was carried out using an anonymous self-administered questionnaire among a convenience sample of 3000 students from three universities (the Université des Montagnes, and the Universities of Douala and Yaounde 1) in Cameroon; 190 students (5.9%) did not consent to the survey. Socio-demographic characteristics and smoking trends were recorded. Logistic regression was used to identify risk factors for smoking. RESULTS: Of the students selected, 1862 (62%) were male. The mean age was 23.3 years. We found that 30.1% of students had tried smoking and that 5.6% (n = 168) reported regular smoking. Smoking prevalence among male and female students was respectively 9.5% and 1%. The mean age of smokers was 24.1 years. Only 12.5% of regular smokers were nicotine-dependent. Factors motivating smoking were pleasure, imitation, snobbery and curiosity. In the multivariate analysis, smoking was statistically associated with age, male sex, exposure to friends who smoke and living with smokers. CONCLUSION: Although the prevalence of smoking found in our study was low, effective tobacco control programmes targeting factors such as age, male sex and peer influence should be implemented in universities. Future studies are needed to evaluate the impact of these interventions.

Asthme et déjections de chauves souris au quartier Bastos de Yaoundé

OBJECTIFS: Une enquête au sein des populations de ce quartier de Yaoundé a révélé en 2009 une prévalence de 36% de signes de l'asthme parmi ses habitants (crises dyspnéiques paroxystiques, rhinites, éternuements, sifflement respiratoire). Ce quartier est densément peuplé de chauves-souris. Le but de notre étude est d'une part de confirmer le taux élevé de l'asthme par une épreuve fonctionnelle simple et de rechercher d'autre part d'éventuels rapports entre l'asthme et les chauves-souris dont les fèces polluent l'environnement immédiat. MÉTHODES Il s'agit d'une enquête basée sur la mesure du DEP (Débit Expiratoire de Pointe) à l'aide du peakflowmètre de Wright. Deux quartiers, Bastos et Ngousso ont été revisités comme en 2009. Une épreuve de peakflowmétrie a été réalisée dans les 2 quartiers (Bastos peuplé de chauve-souris et ayant présenté le plus de signes d'asthme: 36% en 1999). Le quartier Ngousso, non peuplé de chauves-souris, n'a présenté que 2,4% de signes d'asthme en 1999. Cinquante sujets ont été sélectionnés avec leur consentement dans chacun des 2 quartiers pour l'épreuve de peakflowmétrie. La fourchette d'âges pour nos 2 échantillons a ciblé des sujets de 15 à 75 ans. Ce choix était basé sur la capacité de bien exécuter 2 tests peakflowmétriques. Le premier suivi d'une inhalation de 3 bouffées de salbutamol, puis le second 5 minutes plus tard. RÉSULTATS: 45 habitants sur les 50 de Bastos (90%) reconnaissent la présence des chauves-souris dans leur quartier. Seulement 2 de Ngousso (4%) ont pu le faire. Il existe une différence sur ce fait entre les 2 quartiers (p<0.0001). 35 habitants de Bastos (70%) savent reconnaître les déjections de chauves-souris contre (2%) à Ngousso. cette connaissance est significativement différente dans les 2 quartiers (p<0.0001). La variation du DEP (Débit Expiratoire de Pointe) a été franche chez 16 sujets de Bastos versus 2 asthmatiques connus de Ngousso. La prévalence de l'asthme est de 32% à Bastos versus 4% à Ngousso (p<0.0001). CONCLUSION: La prévalence de l'asthme est plus élevée dans le quartier Bastos densément peuplé de chauves-souris. La pollution de l'environnement par les déjections disséminées des chauves-souris autour des habitations y jouerait un rôle. Les déjections de chauves-souris seraient un facteur favorisant de l'asthme. Elles constituent depuis le guano, un milieu favorable de culture des champignons où pousse principalement Mycoplasma capsulatum qui est très allergisant et connu comme facteur déclenchant. Les acariens qui sont une cause bien connue de l'asthme sont également véhiculés par les chauves-souris qui s'infestent depuis leurs fientes en milieu humide. Une étude plus étroite reliant la présence des chauves-souris dans la maison (plafond par exemple) et l'asthme devra être envisagée pour plus de pertinence de notre observation

Impact dépressif de l'infection tuberculeuse sur les cellules immunitaires de défense

OBJECTIFS: La dépression de l'immunité cellulaire en relation avec la tuberculose est davantage évoquée au cours de ses rapports avec l'infection au VIH dont elle constitue l'infection opportuniste de première ligne. Dans le présent travail, nous avons voulu mettre en exergue la dépression de l'immunité causée par la tuberculose elle-même. MÉTHODES: A l'Hôpital Jamot, du 1er janvier au 30 mars 2013, nous avons recruté de façon consécutive 63 patients tuberculeux BK+. Nous avons inclus des patients des 2 sexes âgés de 18 ans au moins, VIH négatifs, en primo traitement et consentants. A J0 et à J60 du traitement antituberculeux, nous avons prélevé 5 ml de sang à chaque patient pour le comptage par cytométrie de flux des cellules immunitaires. Deux appareils ont été utilisés: le CELL-DYN 3200 pour les leucocytes totaux, les lymphocytes totaux et les granulocytes et le BD FACS Count pour la numération des lymphocytes T: CD4 et CD8. RÉSULTATS: Le traitement de la tuberculose nous a permis d'observer une augmentation des cellules immunitaires du sang. La moyenne absolue des CD4 est passée de 537 à 957/mm3 en 60 jours de traitement (p < 0,001). La moyenne des CD8 quant à elle est passée de 288 à 412/mm3 (p < 0,0039). Le rapport CD4/CD8 est passé de 1,6 à 2,04 (p < 0,001). Le taux moyen des lymphocytes totaux est passé de 1450 à 1960/mm3 (p <0,005). Celui des monocytes est passé de 125 à 584/mm3 (p < 0,001). Le taux moyen des PNN et granulocytes a légèrement baissé. CONCLUSION: La tuberculose, infection mycobactérienne, détruit gravement les cellules de l'immunité cellulaire comme cela est observé au cours de l'infection à VIH. La malnutrition dans nos milieux serait un facteur aggravant

[Nontuberculous purulent pleural effusion in adults in Yaounde, Cameroon]. / La pleurésie purulente non tuberculeuse de l'adulte à Yaoundé (Cameroun).

OBJECTIVE: The aim of this study is to analyze current etiologic, bacteriologic and prognostic features of nontuberculous purulent pleural effusion in adults in Yaounde, Cameroon. METHODS: This study prospectively included 54 adults hospitalized for community-acquired nontuberculous purulent pleural effusion in the chest-disease clinic of the Jamot Hospital in Yaounde from August 2007 to July 2010. RESULTS: The study included 34 men and 20 women with a mean age of 40.8 ± 16.4 years. At least one or more predisposing condition or underlying disease was found in 59.2%. The most frequent predisposing condition was HIV infection, seen in 35.2% of patients. In 92.6% of patients (n=50), purulent pleural effusion followed acute bronchopulmonary infection. Positive cultures of pleural fluid were found in half the patients. Streptococcus pneumoniae was the most common bacteria identified (41.4%) followed by Staphylococcus aureus (20.7%). Anaerobic bacteria were isolated in only 13.4% (n=4). Improvement was achieved in 79.6% of patients (n=43) and the in-hospital mortality rate was 3.7%. The mean duration of hospitalization was 26.8±15.6 days. CONCLUSION: This study indicates that HIV infection is the most frequent predisposing condition for community-acquired nontuberculous purulent pleural effusion in adults in Yaounde. The most commonly isolated bacterial pathogen was S. pneumoniae. Although the mortality rate of this disease is low, its prevention by proper management of acute respiratory tract infection is important.

[Clinical characteristics, microbiologic findings and outcome of non-tuberculous purulent pleural effusion in HIV-infected and non HIV-infected adult patients in Yaounde, Cameroon]. / Caractéristiques cliniques, bactériologiques et évolutives de la pleurésie purulente non-tuberculeuse chez les patients adultes séropositifs et séronégatifs au VIH à Yaoundé, Cameroun.

OBJECTIVE: To investigate the impact of HIV infection on clinical presentation, etiologic features and outcome of non-tuberculous purulent pleural effusion in adult patients in Yaounde. METHODS: We prospectively studied 55 consecutive patients aged 15 years and above, hospitalized in chest clinic of Yaounde Jamot Hospital for non-tuberculous purulent pleural effusion from August 2007 to September 2010. RESULTS: Twenty (36.4%) of the 55 patients were HIV-positive and 35 (63.6%) were HIV-negative. The mean age of HIV-positive patients was 37.5±11.7 years compare to 43.2 ±18.5 years on HIV-negative patients (P=0.159). Twelve (60%) HIV-positive patients were females compared to eight (22.6%) of HIV-negative patients (P=0.006). No significant differences were found between the two groups of patients in regard to clinical and radiological features. The mean hemoglobin level was 10.5±2.8g/L in HIV-negative patients and 8.8±2.2g/L in HIV-positive patients (P=0.031). Streptococcus pneumoniae was the most common single bacterial etiology in the two groups with four (50%) cases in HIV-positive and eight (38.1%) cases in HIV-negative. Poor outcome (failure of thoracocenthesis or chest tube drainage and death) was observed in eight (40%) HIV-infected patients and only in four (11.4%) non-infected-HIV patients (P=0.019). CONCLUSION: The prevalence of HIV infection among adult patients with non-tuberculous purulent pleural effusion in Yaounde is high. HIV infection does not seem to have any impact on clinical, radiological and bacteriologic characteristics of patients suffering from purulent pleural effusion, but it seems to modify hematologic parameters of these patients. Failure of thoracocenthesis or chest tube drainage was significantly most frequent in HIV-infected patients.

Genetic and biological properties of HIV type 1 isolates prevalent in villagers of the Cameroon equatorial rain forests and grass fields: further evidence of broad HIV type 1 genetic diversity.

To understand the evolution of HIV-1, the genetic and biological characteristics of viruses that infect persons living in regions in which the virus has been evolving for several decades must be studied. Thus, we investigated teh genetic subtypes, coreceptor usage, and syncytium-inducing ability of viruses in 47 HIV-1-infected blood samples from individuals living in rural villages in the equatorial rain forest and grass field regions in Cameroon. Heteroduplex mobility analysis (HMA) of gag (part of p24 and p7) and env (C2V5) or sequence and phylogenetic analysis of gag (part of p24 and p7), pol (protease), and env (C2V5), revealed a broad HIV-1 group M genetic diversity. Subtype analysis revealed genetic evidence of seven subtypes (A, C, D, F, G, H, and J) and three circulating recombinant froms (CRFs) (CRF01_AE, CRF02_AG, and CRF11_cpx). Only 15 (32%) of the 47 samples analyzed revealed a concordant subtype in all three genes (gag, pol, and env), while discordant subtypes and CRFs were identified for the remaining 32 (68%) samples. Two patterns of HIV-1 diversity could be discerned in two provinces. While more concordant subtypes in gag, pol, and env genes were identified in villages of South province (10 of 13, 77%), the HIV-1 diversity in the West province was characterized by intersubtype recombinants (63%). Five new intersubtype recombinants were identified including Agag Jpol Genv, Ggag Upol Aenv, AGgag Jpol Aenv, Agag AGpol Henv, and Cgag AGpol AGenv. All of the 40 viruses tested used the R5 coreceptor, of which four also used the X4 coreceptor. Four viruses were able to induce syncytia in MT-2 cells, however, syncytium induction did not correlate with coreceptor usage. This study further reveals the complexity of HIV-1 infection in rural Cameron and points to the future of the global epidemic, which may be characterized by more genetically diverse viruses.

Reactivity of a new HIV-1 group O third generation A-HIV-1/-2 assay with an unusual HIV-1 seroconversion panel and HIV-1 group O/group M subtyped samples.

It was shown previously that about 97% of the anti-HIV-1 group O strain-positive samples were detected by crossreaction with native HIV-1 gp160 (Van Binsbergen et al., Evaluation of a new third generation anti-HIV-1/anti-HIV-2 assay with increased sensitivity for HIV-1 group O, J. Virol. Methods 60 (1996) 131-137). Fourteen out of 17 new anti-HIV-1 group O positive samples, selected with the Enzygnost HIV-1/2 plus assay, were already reactive when tested with HIV-1 gp160. When tested by the Vironostika HIV Uni-Form II plus O microELISA all 17 samples were reactive, demonstrating the necessity to implement an HIV-1 group O-specific antigen in the assay. On the other hand, it was surprisingly found that 40 out of 43 (93%) of anti-HIV-1 group M-positive samples, belonging to strain A, B, C, D, E or F, were detected by crossreaction with the HIV-1 group O (strain ANT70) synthetic peptide incorporated in the Vironostika HIV Uni-Form II plus O. Only HIV-1 subtype D-positive samples did not react with this peptide, presumably because of the presence of a histidine residue in the immunodominant region of HIV-1 subtype D gp41. Both crossreactions make the Vironostika HIV Uni-Form II plus O microELISA also sensitive for anti-HIV-1-positive samples originating from different geographical regions and resulting from different HIV-1 subtype infections. With an unusual seroconversion panel in which p24 Ag was present persistently, many anti-HIV-1/-2 assays produce alternating positive/negative results in anti-HIV antibody-positive bleeds. It was shown that the use of viral p24 and gp160 in a direct sandwich, allowing detection of anti-HIV IgG and IgM, explains the identification of all anti-HIV-positive bleeds by the Vironostika HIV Uni-Form II plus O. The high sensitivity of the plus O assay was confirmed with clinical samples of a so-called anti-HIV-1 low titer panel. The specificity of the Vironostika HIV Uni-Form II plus O determined in five blood transfusion centers, based on 135070 tests, was 99.97%.

Respiratory symptoms and peak expiratory flow in survivors of the Nyos disaster.

In August 1986, gases from the Nyos volcanic lake killed 1,746 persons in northwestern Cameroun, but 1,500 others living in the affected area survived. Gas emanations contained carbon dioxide, sulfur dioxide, and hydrogen sulfide. The objective of this study was to evaluate the delayed respiratory consequences of the inhalation of such volcanic gases. Two groups of subjects living in the same area, exposed (Nyos group; n = 381) or not exposed (control group; n = 128) to Nyos gases, were evaluated with a short questionnaire and by measurement of peak expiratory flow (PEF, percent predicted) in March 1991. Eleven percent of the subjects smoked, more often men than women (23% vs 4%; p < 0.001). In the whole population (exposed and unexposed), smoking was associated with a 3.6-fold increase in the frequency of cough (p < 0.001) and with a 6-fold increase in the frequency of sputum production (p < 0.005), but not with a decrease in PEF. There was no difference in the frequency of dyspnea, cough, sputum production, and PEF between Nyos and control groups. We conclude that 55 months after the emanation of gases from Nyos volcanic lake, there was no difference in respiratory symptoms, and PEF between survivors who inhaled volcanic gases and control subjects, whereas smoking was associated with cough and sputum production.

HIV-1 subtype O: epidemiology, pathogenesis, diagnosis, and perspectives of the evolution of HIV.

HIV-1 subtype O is a new HIV variant originating in the West-Central African region, with highest prevalences in countries such as Cameroon, Equatorial Guinea and Gabon. Detection of antibodies to HIV-1 subtype O can pose problems in unmodified ELISA tests, and confirmation of anti-HIV-1 subtype O in immunoblot may give false negative results in some specimens. Nucleic acid-based assays designed for HIV-1 detection do not amplify or detect sequences from HIV-1 subtype O. In their env sequences, HIV-1 subtype O strains show a higher heterogeneity than the classical HIV-1 subtypes, leading to the conclusion that HIV-1 subtype O has been introduced into the human population only recently. Further, unidentified subtypes are also likely to exist.

Emanations de l'huile de palme chauffante: facteur de l'asthme

Des asthmatiques consultant en Pneumologie a l'Hopital Jamot de Yaounde se sont plaints de toux et de dyspnee apres inhalation des fumees qui se degagaient du recipient dans lequel chauffait de l'huile de palme rouge; tres utilisee dans la cuisine traditionnelle. Reproduisant les conditions normales d'une cuisine; les auteurs ont expose 59 asthmatiques et 54 non asthmatiques a ces fumees. 47;45 pour cent des asthmatiques ont fait une crise de dyspnee classique. Mesurant le debit expiratoire de pointe (DEP) a l'aide d'un DEP metre avant; 5; 10 et 15 minutes apres l'exposition aux emanations; ils ont constate une diminution significative du DEP chez 16 patients presentant une toux spasmodique ou des rales sibilants soit 27;11 pour cent des asthmatiques. Seulement 24;1 pour cent des non asthmatiques ont presente des troubles mineurs (eternuements). Aucun n'a presente de diminution du DEP superieure ou egale a 20 pour cent; et aucun signe respiratoire n'a ete observe chez les non asthmatiques. Il existe donc une hyperreactivite bronchique de reaction aux emanations de l'huile de palme chauffante chez les sujets asthmatiques

[Diagnostic value of abdominal echography in cirrhosis of the African black. A study of 99 cases]. / Valeur diagnostique de l'échographie abdominale dans la cirrhose du noir africain. Une étude de 99 cas.

We reviewed sonographic findings and evaluated the impact of conventional ultrasound (US) in the management of 99 consecutive black africans with liver cirrhosis. Patients were studied in the University teaching Hospital of Yaoundé (Cameroon). There were 73 males and 26 females, with a mean age of 49 years (range 15 to 71 years). 90 p. cent patients presented with symptoms suggestive of liver disease. The commonest sonographic liver abnormalities were: echo coarseness with poor depiction of intrahepatic vessels, irregularity of the liver surface, hypertrophy of caudate lobe, hepatomegaly, and decreased beam penetration through the liver. Ascitis and other signs of portal hypertension were present respectively in 44 p. cent and 33 p. cent of subjects. 15 p. cent of subjects had hepatocellular carcinoma. Choletithiasis was seen in 6 subjects (6%), and chronic pancreatitis in 3 patients (3 p. cent). For 21 patients (21 p. cent), US depicted significant abdominal disease which was not clinically suspected, and for 10 patients (10 p. cent), it discovered silent liver cirrhosis. Our findings suggest that conventional US may be a useful tool in the management of some black african subjects with liver cirrhosis.