Chronic Obstructive Pulmonary Disease in Cameroon: Prevalence and Predictors-A Multisetting Community-Based Study.

Objective: Little is known concerning chronic obstructive pulmonary disease (COPD) in Sub-Saharan Africa (SSA), where the disease remains underdiagnosed. We aimed to estimate its prevalence in Cameroon and look for its predictors. Methods: Adults aged 19 years and older were randomly selected in 4 regions of Cameroon to participate in a cross-sectional community-based study. Data were collected in the participant's home or place of work. Spirometry was performed on selected participants. COPD was defined as the postbronchodilator forced expiratory volume in 1 second/forced vital capacity ratio (FEV1/FVC) < lower limit of normal, using the global lung initiative (GLI) equations for Black people. Binomial logistic regression was used to seek COPD-associated factors. The strength of the association was measured using the adjusted odds ratio (aOR). Results: A total of 5055 participants (median age (25th-75th percentile) = 43 (30-56) years, 54.9% of women) were enrolled. COPD prevalence (95% confidence interval (95% CI)) was 2.9% (2.4, 3.3)%. Independent predictors of COPD (aOR (95% CI)) were a high educational level (4.7 (2.0, 11.1)), living in semiurban or rural locality (1.7 (1.4, 3.0)), tobacco smoking (1.7 (1.1, 2.5)), biomass fuel exposure (1.9 (1.1, 3.3)), experience of dyspnea (2.2 (1.4, 3.5)), history of tuberculosis (3.6 (1.9, 6.7)), and history of asthma (6.3 (3.4, 11.6)). Obesity was protective factor (aOR (95%CI) = 0.3 (0.2, 0.5)). Conclusion: The prevalence of COPD was relatively low. Alternative risk factors such as biomass fuel exposure, history of tuberculosis, and asthma were confirmed as predictors.

Viral etiology of lower respiratory tract infections in adults in the pre-COVID-19 pandemic era: A cross-sectional study in a single center experience from Cameroon.

Background and Aims: Respiratory viruses are responsible for the majority of lower respiratory tract infections (LRTIs) worldwide. However, there is a gap on the epidemiology of viral LRTIs in adults in sub-Saharan African countries. In Cameroon, like in other countries, the role of viral respiratory pathogens in the etiology of LRTIs in adults is helpful for clinical management. This study aimed to determine the viral aetiologies of LRTIs among hospitalized adults in a reference center for respiratory diseases in the town of Yaounde in Cameroon and its surroundings. Methods: A cross-sectional study was conducted from January 2017 to January 2018 at Jamot Hospital in Yaounde (Cameroon). Clinical and demographic information; BAL and sputa were collected from hospitalized patients meeting LRTI case definitions. The clinical samples were investigated for respiratory pathogens with a commercial Reverse Transcriptase Real-Time Polymerase Chain Reaction (RT-PCR) targeting 21 viruses, cultures for bacterial and fungal infections. Results: The 77 included adult patients with LRTIs had an appropriate clinical sample for microbial investigations. A viral agent was detected in 22.1% (17/77) samples. The main viruses detected included rhinovirus (10/77), coronavirus (hCoV-OC43 and hCoV-229E), and influenza A virus (3/77 each). A concomitant viral and bacterial co-infection occurred in 7.8% of patients (6/77) while viral co-infection occurred in one patient (1.3%). No Severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) was detected in clinical samples. Most patients were under antimicrobials before getting diagnosed. Conclusions: Respiratory viruses account for 22.1% of LRTIs in hospitalized patients in this study. Despite prior antimicrobial therapy and delay, rhinovirus, coronavirus and influenza A virus were the most detected in patients in the pre-COVID-19 pandemic era in a single center experience from Cameroon.

Sleep Apnea Syndrome: Prevalence and Comorbidity with Other Non-communicable Diseases and HIV Infection, among Hospitalized Patients in Yaoundé, Cameroon.

BACKGROUND: Sleep apnea syndrome (SAS), a growing public health threat, is an emerging condition in sub-Saharan Africa (SSA). Related SSA studies have so far used an incomplete definition. This study is aimed at assessing SAS using an American Academy of Sleep Medicine (AASM) complete definition and at exploring its relationship with comorbidities, among patients hospitalized in a Cameroonian tertiary hospital. METHODS: This cross-sectional study was conducted in cardiology, endocrinology, and neurology departments of the Yaoundé Central Hospital. Patients aged 21 and above were consecutively invited, and some of them were randomly selected to undergo a full night record using a portable sleep monitoring device, to diagnose sleep-disordered breathing (SDB). SAS was defined as an apnea - hypopnea index (AHI) ≥ 5/h, associated with either excessive daytime sleepiness or at least 3 compatible symptoms. Moderate to severe SAS (MS-SAS) stood for an AHI ≥ 15/h. We used chi-square or Fisher tests to compare SAS and non-SAS groups. Findings. One hundred and eleven patients presented a valid sleep monitoring report. Their mean age ± standard deviation (range) was 58 ± 12.5 (28-87) years, and 53.2% were female. The prevalence (95% confident interval (CI)) of SAS was 55.0 (45.7, 64.2)% and the one of MS-SAS 34.2 (25.4, 43.1)%. The obstructive pattern (90.2% of SAS and 86.8% of MS-SAS) was predominant. The prevalence of SAS among specific comorbidities ranged from 52.2% to 75.0%. Compared to SAS free patients, more SAS patients presented with hypertension (75.4% vs. 48.0%, p = 0.005%), history of stroke (36.7% vs. 32.0%, p = 0.756), cardiac failure (23.0% vs. 12.0%, p = 0.213), and combined cardiovascular comorbidity (80.3% vs. 52.0%, p = 0.003). Similar results were observed for MS-SAS. Metabolic and neuropsychiatric comorbidities did not differ between SAS and SAS-free patients. CONCLUSION: The SAS diagnosed using modified AASM definition showed high prevalence among patients hospitalized for acute medical conditions, as it was found with SDB. Unlike HIV infection, metabolic and brain conditions, cardiovascular comorbidities (hypertension and cardiac failure) were significantly more prevalent in SAS patients.

Spirometric reference equations for Cameroonians aged 4 to 89 years derived using lambda, mu, sigma (LMS) method.

BACKGROUND: Spirometric reference values are well known in several ethnic groups but the normative spirometric values of blacks living in Africa have been less studied. The purpose of this study is to establish normative spirometric equations from a representative population of Cameroonian children and adults and compare these equations with those developed by the Global Lung Initiative (GLI) and in Nigerians. METHODS: Spirometric data from healthy Cameroonians aged 4-89 years randomly collected between 2014 and 2018 were used to derive reference equations using generalized additive model for location (mu), shape (lambda) and scale (sigma). RESULTS: A total of 625 children and adolescents (290 males and 335 females) and 1152 adults (552 males and 600 females) were included in the study. The prediction equation for spirometric index was written as: M = Exp[a0 + a1*ln (Height) + a2*ln (Age) + Mspline, Mspline was age related spline contribution]. Applying the GLI standards for African Americans resulted in overall values greater than those found in our study for forced expiratory volume in 1s (FEV1) and forced vital capacity (FVC). These values were very close in children and adolescents while the values obtained with the GLI equations for African Americans were significantly higher in adults. FEV1/FVC ratio in our study was similar for adult males but lower in adult females (88% vs 85%, difference = + 3.5%) when applying Nigerian standards. CONCLUSIONS: FEV1 and FVC of the Cameroonian infant and adolescent population are very close to those of black Americans. However, FEV1 and FVC of Cameroonian adults are significantly lower than those of black American adults. These equations should allow a more suitable interpretation of spirometry in the Cameroonian population.

Incidence and factors associated with unfavourable treatment outcome among patients with rifampicin-resistant pulmonary tuberculosis in Yaoundé, Cameroon.

INTRODUCTION: in Cameroon patients with multidrug/rifampicin resistant pulmonary tuberculosis (MDR/RR-PTB) are treated with a 9-11 month standardised shorter treatment regimen. Despite its effectiveness, factors associated with the occurrence of an unfavourable treatment outcome in this group of patients are not known. Determine the incidence and identify factors associated with an unfavourable treatment outcome among patients with rifampicin resistant pulmonary tuberculosis (RR-PTB) in Yaoundé. METHODS: we conducted a retrospective record review of all consecutive patients with bacteriologically confirmed RR-PTB followed up at the specialised MDR/RR-TB treatment centre of the Jamot Hospital in Yaoundé (JHY) from January 2013 to November 2019. A patient was classified as having an unfavourable outcome if he/she had treatment failure, died or was lost to follow-up during the course of treatment. RESULTS: a total of 242 RR-PTB patients with a mean age of 35.59 ± 12.02 years including 144 (59.5%) males were registered. Forty-nine (49) of the 242 patients had an unfavourable treatment outcome giving a cumulative incidence of 20.20% (95% confidence interval (95% CI): 15.40-25.90%). Multivariable analysis revealed that patients with an unfavourable outcome were more likely to be males (odds ratio (OR): 2.94; 95% CI: 1.24-7.00, p= 0.015), HIV infected (OR: 2.67; 95% CI: 1.17-6.06, p = 0.019), and have a baseline haemoglobin level ≤ 10g/dl (OR: 2.87; 95% CI: 1.25-6.58, p = 0.013). CONCLUSION: the rate of an unfavourable treatment outcome among patients with RR-PTB at the specialised MDR/RR-TB treatment centre of the JHY is relatively high. The male sex, HIV infection and moderate to severe anaemia are independent factors associated with an unfavourable treatment outcome.

Prevalence and determinants of chronic kidney disease in urban adults' populations of northern Cameroon.

BACKGROUND: Chronic kidney disease (CKD) is a major health problem with growing prevalence in sub-Saharan Africa. AIM: Assess the prevalence and determinants of CKD in Garoua and Figuil cities of the North region of Cameroon. METHODS: A cross-sectional survey was conducted from January to June 2018 in the two cities, using a multi-level cluster sampling. All adults with low estimated glomerular filtration rate (eGFR) (< 60 ml/min/1.73 m2) by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and/or albuminuria (≥ 30 mg/g) were reviewed three months later. Logistic regression models (accounting for the sampling strategy) were used to investigate the predictors of the outcomes. RESULTS: A total of 433 participants were included, with a mean age (95%CI) of 45.0 (43.4-46.6) years, 212 (48.7%) men, 294 (67.9%) from Garoua and 218 (45.6%) with no formal education. Risk factors for chronic nephropathy were highly prevalent including longstanding use of street medications (52.8%), herbal medicines (50.2%) and non-steroidal anti-inflammatory drugs (50%), alcohol consumption (34.4%), hypertension (33.9%), overweight/obesity (33.6%), hyperuricemia (16.8%), smoking (11.3%) and hyperglycemia (6.5%). The prevalence of CKD was 11.7% overall, 10.7% in Garoua and 13% in Figuil participants. Equivalents figures for CKD G3-5 and albuminuria were 2.8%, 2.0% and 4.5%; and 9.1%, 9.3% and 8.5%, respectively. History of diabetes, increase systolic blood pressure, hyperglycemia and hyperuricemia were predictors of CKD. CONCLUSION: The prevalence of CKD is as high in these northern cities as previously reported in southern cities of Cameroon, driven mostly by known modifiable risk factors of chronic nephropathy.

Cytokine profile in the sputum of subjects with post-tuberculosis airflow obstruction and in those with tobacco related chronic obstructive pulmonary disease.

BACKGROUND: Previous studies have shown that tuberculosis (TB) is a risk factor for chronic airflow limitation. Chronic obstructive pulmonary disease (COPD) is recognized as the result of chronic inflammation, usually related to noxious particles. Post-TB airflow obstruction and tobacco-related COPD have the same functional pathway characterized by persistent airflow limitation. We sought to compare the profile of 29 cytokines in the sputum of subjects with post-TB airflow obstruction and those with COPD related to tobacco. RESULTS: The forced expiratory volume in the first second (FEV1) and forced expiratory volume/forced vital capacity (FEV/FVC) ratio were lower in the COPD patients with the history of smoking compared to the post-TB airflow obstruction subgroup. The stages of the disease were more advanced in COPD / tobacco patients. Among the cytokines, IL-1α, IL-1ß, MIP-1ß, sCD40L and VEGF levels were higher in COPD patients, compared to the controls with p values ​​of 0.003, 0.0001, 0.03, 0.0001 and 0.02 respectively. When the two COPD subgroups were compared, IL-1α, IL-6, TNF-α and IL-8 levels were higher in the COPD patients with the history of tobacco compared to the COPD patients with the history of TB with p-values ​​of 0.031, 0.05, 0.021 and 0.016, respectively. CONCLUSION: COPD related to tobacco is more severe than post-TB airflow obstruction. The pathogenesis of post-TB airflow obstruction appears to involve the cytokines IL-1RA, IL-1α, IL-1ß, IL-17, GRO and sCD40L, while COPD related to tobacco involves more cytokines.

Analysis of Haemophilus species in patients with respiratory tract infections in Yaoundé, Cameroon.

OBJECTIVES: To identifyHaemophilus species and characterize antimicrobial susceptibility of isolates from patients with respiratory tract infections (RTIs) in Cameroon. METHODS: Isolates (n = 95) were from patients with RTIs obtained from two Hospitals in Yaoundé, Cameroon. Isolates were identified by biochemical assay, PCR-based method, MALDI-TOF and whole genome sequencing. Antibiotic minimum inhibitory concentrations were determined by E-test. RESULTS: H. influenzae was the most prevalent species varying from 76.8% to 84.2% according to different methods. The isolates were mainly nontypable (n = 70, 96%). Three isolates of H. influenzae were capsulated (b, e and f). The isolates were genetically diverse and 40 unique sequence types were identified including 11 new ones. Resistance to ampicillin was observed among 55.3% (52/94) and 9% (14/52) produced TEM-1 ß-lactamase. PBP3 mutations occurred in 57.7% of ampicillin resistant isolates (30/52). Eleven isolates were chloramphenicol resistant with 80% producing chloramphenicol acetyltransferase (8/10). Four Haemophilus isolates were rifampicin resistant with two mutations in rpoB gene. Five isolates were ciprofloxacin resistant and harbored mutations in the quinolone resistance determining regions of gyrA and parC genes. CONCLUSION: H. influenzae isolates are highly diverse and show high levels of antibiotic resistance. H. influenzae serotype b is still circulating in the post-vaccination era.

Obstructive sleep apnea and hypopnea syndrome in patients admitted in a tertiary hospital in Cameroon: Prevalence and associated factors.

PURPOSE: Obstructive sleep apnea and hypopnea syndrome (OSAHS) is poorly documented in Sub-Saharan Africa, especially in the hospital setting. The aim of this study was to determine its prevalence and to investigate the associated factors in patients admitted in a tertiary referral hospital in Cameroon. METHODS: In this cross-sectional study conducted in the Cardiology, Endocrinology and Neurology departments of the Yaounde Central Hospital; all patients aged 21 and older were included consecutively. A sample of randomly selected patients was recorded using a portable sleep monitoring device (PMD). OSAHS was defined as apnea-hypopnea index (AHI) ≥ 5/hour (with > 50% of events being obstructive) and moderate to severe OSAHS as an AHI > 15/hour. Logistic regression was used to identify factors associated to OSAHS. RESULTS: Of the 359 patients included, 202 (56.3%) patients were women. The mean age (standard deviation) was 58 (16) years. The prevalence of OSAHS assessed by PMD (95% CI) was 57.7% (48.5-66.9%), 53.8% in men and 62.7% in women (p = 0.44). The median (25th-75th percentiles) AHI, body mass index and Epworth Sleepiness Scale score of OSAHS patients were 17 (10.6-26.9)/hour, 27.4 (24.7-31.6) kg/m2 and 7 (5-9) respectively. The only factor associated to moderate to severe OSAHS was hypertension [odds ratio (95% CI)]: 3.24 (1.08-9.72), p = 0.036. CONCLUSION: OSAHS is a common condition in patients in this health care centre of Cameroon. In the hospital setting, screening for OSAHS in patients with hypertension is recommended.

Bacterial Aetiologies of Lower Respiratory Tract Infections among Adults in Yaoundé, Cameroon.

Lower respiratory tract infections (LRTIs) remain a challenge in African healthcare settings and only few data are available on their aetiology in Cameroon. The purpose of this study was to access the bacterial cause of LRTIs in patients in Cameroon by two methods. Methods. Participants with LRTIs were enrolled in the referral centre for respiratory diseases in Yaoundé city and its surroundings. To detect bacteria, specimens were tested by conventional bacterial culture and a commercial reverse-transcriptase real-time polymerase chain reaction (RT-PCR) assay. One hundred forty-one adult patients with LRTIs were enrolled in the study. Among the participants, 46.8% were positive for at least one bacterium. Streptococcus pneumoniae and Haemophilus influenzae were the most detected bacteria with 14.2% (20/141) followed by Klebsiella pneumoniae, 9.2% (13/141), Staphylococcus aureus, 7.1% (10/141), and Moraxella catarrhalis, 4.3% (6/141). Bacterial coinfection accounted for 23% (14/61) with Haemophilus influenzae being implicated in 19.7% (12/61). The diagnostic performance of RT-PCR for bacteria detection (43.3%) was significantly different from that of culture (17.7%) (p< 0.001). Only Streptococcus pneumoniae detection was associated with empyema by RT-PCR (p<0.001). These findings enhance understanding of bacterial aetiologies in order to improve respiratory infection management and treatment. It also highlights the need to implement molecular tools as part of the diagnosis of LRTIs.

Diagnostic accuracy and usefulness of the Genotype MTBDRplus assay in diagnosing multidrug-resistant tuberculosis in Cameroon? a cross-sectional study.

BACKGROUND: Drug-resistant tuberculosis, especially multidrug-resistant tuberculosis (MDR-TB), is a major public health problem. Effective management of MDR-TB relies on accurate and rapid diagnosis. In this study, we assessed the diagnostic accuracy of the Genotype MTBDRplus assay in diagnosing MDR-TB in Cameroon, and then discuss on its utility within the diagnostic algorithm for MDR-TB. METHODS: In this cross-sectional study, 225 isolates of Mycobacterium tuberculosis cultured from sputum samples collected from new and previously treated pulmonary tuberculosis patients in Cameroon were used to determine the accuracy of the Genotype MTBDRplus assay. We compared the results of the Genotype MTBDRplus assay with those from the automated liquid culture BACTEC MGIT 960 SIRE system for sensitivity, specificity, and degree of agreement. The pattern of mutations associated with resistance to RIF and INH were also analyzed. RESULTS: The Genotype MTBDRplus assay correctly identified Rifampicin (RIF) resistance in 48/49 isolates (sensitivity, 98% [CI, 89%-100%]), Isoniazid (INH) resistance in 55/60 isolates (sensitivity 92% [CI, 82%-96%]), and MDR-TB in 46/49 (sensitivity, 94% [CI, 83%-98%]). The specificity for the detection of RIF-resistant and MDR-TB cases was 100% (CI, 98%-100%), while that of INH resistance was 99% (CI, 97%-100%). The agreement between the two tests for the detection of MDR-TB was very good (Kappa = 0.96 [CI, 0.92-1.00]). Among the 3 missed MDR-TB cases, the Genotype MTBDRplus assay classified two samples as RIF-monoresistant and one as INH monoresistant. The most frequent mutations detected by the Genotype MTBDRplus assay was the rpoB S531 L MUT3 41/49 (84%) in RIF-resistant isolates, and the KatG S315 T1 (MUT1) 35/55 (64%) and inhA C15T (MUT1) 20/55 (36%) mutations in INH-resistant isolates. CONCLUSION: The Genotype MTBDRplus assay had good accuracy and could be used for the diagnosis of MDR-TB in Cameroon. For routine MDR-TB diagnosis, this assay could be used for Mycobacterium tuberculosis cultures containing contaminants, to complement culture-based drug susceptibility testing or to determine drug resistant mutations.

Development and validation of a prognostic score during tuberculosis treatment.

BACKGROUND: Death under care is a major challenge for tuberculosis (TB) treatment programs. We derived and validated a simple score to predict mortality during tuberculosis treatment in high endemicity areas. METHODS: We used data for patients aged ≥15 years, diagnosed and treated for tuberculosis at the Yaounde Jamot Hospital between January 2012 and December 2013. Baseline characteristics associated with mortality were investigated using logistic regressions. A simple prognosis score (CABI) was constructed with regression coefficients for predictors in the final model. Internal validation used bootstrap resampling procedures. Models discrimination was assessed using c-statistics and calibration assessed via calibration plots and the Hosmer and Lemeshwow (H-L) statistics. The optimal score was based on the Youden's index. RESULTS: A total of 2250 patients (men 57.2%) with a mean age of 35.8 years were included; among whom 213 deaths (cumulative incidence 9.5%) were recorded. Clinical form of tuberculosis (C), age (A, years), adjusted body mass index (B, BMI, kg/m2) and status for HIV (Human immunodefiency virus) infection (I) were significant predictors in the final model (p < 0.0001) which was of the form Death risk = 1/(1 + e - (-1.3120 + 0.0474 ∗ age - 0.1866 ∗ BMI + 1.1637 (if smear negative TB) + 0.5418(if extra - pulmonary TB) + 1.3820(if HIV+))). The c-statistic was 0.812 in the derivation sample and 0.808 after correction for optimism. The calibration was good [H-Lχ2 = 6.44 (p = 0.60)]. The optimal absolute risk threshold was 4.8%, corresponding to a sensitivity of 81% and specificity of 67%. CONCLUSIONS: The preliminary promising findings from this study require confirmation through independent external validation studies. If confirmed, the model derived could facilitate the stratification of TB patients for mortality risk and implementation of additional monitoring and management measures in vulnerable patients.

Complex sleep apnea at auto-titrating CPAP initiation: prevalence, significance and predictive factors.

INTRODUCTION: Obstructive sleep apnea (OSA) patients may develop central respiratory events under continuous positive airway pressure (CPAP), referred to as complex sleep apnea (CompSA). OBJECTIVE: We aimed to assess prevalence and predictive factors of complex apnea and to evaluate treatment response to CPAP. METHODS: Within a retrospective cohort study, we assessed clinical data of OSA patients, attending the sleep lab during a 15-months period. Included participants underwent two consecutive polysomnographies; baseline diagnosis and treatment trial. Complex apnea patients, defined by a central apnea index ≥ 5 per hour during pressure auto-titration, were compared to remainders. RESULTS: Among 263 included patients, the prevalence of complex apnea was 9.1%. The mean apnea hypopnea index only dropped from 52.7 to 39.9 per hour in CompSA patients, while it improved from 40.9 to 7.3 in patients without CompSA. Although a decreased sleep-fragmentation under CPAP was observable in both groups, the enhancement of Non-REM sleep was superior in patients without CompSA. The CompSA patients showed higher median apnea-hypopnea, mixed apnea and central apnea indices at baseline and displayed higher rates of comorbid heart failure and obstructive pulmonary disease, but no higher severity of associated daytime fatigue and sleepiness symptoms. CONCLUSION: Despite evidenced partial improvement of obstructive events, nocturnal hypoxemia and sleep fragmentation, the occurrence of complex apnea presented here as a clear therapeutic failure of auto-titrating CPAP and was associated with heart failure, COPD and higher central and mixed apnea indices at baseline.

Evaluation of factors affecting adherence to asthma controller therapy in chest clinics in a sub-Saharan African setting: a cross-sectional study.

BACKGROUND: Adherence to controller therapy in asthma is a major concern during the management of the disease. OBJECTIVE: To determine the adherence rate and identify the predictors of low adherence to asthma controller therapy. METHODS: A cross-sectional study including asthma patients was conducted from November 1, 2012 to May 31, 2013 in 4 chest clinics in Cameroon. The adherence to asthma treatment was rated using Morisky Medication Adherence Scale. A multivariate logistic regression analysis was performed for the identification of factors associated with adherence to asthma treatment. RESULTS: Among the 201 asthma patients included, 133 (66.2%) were female. The mean age of participants was 41.2 years. Sixty-one (30.3%) of the patients did not visit the chest physician during the last year prior to the study. Asthma was well controlled in 118 patients (58.7%). The prevalence of low adherence rate to asthma controller therapy was 44.8% and the absence of any chest specialist visit within the last 12 months was the only factor associated with the low adherence rate to asthma treatment (OR 5.57 ; 95% CI 2.84-10.93). CONCLUSION: The adherence rate to asthma controller therapy in Cameroon is low and it could be improved if scheduled visits are respected by patients.

Prevalence of obstructive lung disease in an African country using definitions from different international guidelines: a community based cross-sectional survey.

BACKGROUND: Obstructive lung disease (OLD), a major global public health problem, has been less investigated in African countries. We assessed the prevalence and determinants of OLD in Yaounde (the capital city of Cameroon), using internationally agreed definitions. METHODS: Participants were adults (age >19 years) screened during a community-based survey between December 2013 and April 2014. Air flow limitation (AFL) was based on a pre-bronchodilator forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) below the lower limit of normal (LLN, AFL-LLN). Chronic obstructive pulmonary disease (COPD) was based on post-bronchodilator FEV1/FVC ratio < LLN (COPD-LLN). RESULTS: Of the 1287 subjects included, 51.9% were female, 9.3% were current smokers and their mean age was 34.4 ± 12.8 years. Forty-nine (3.8%, 95% CI 2.8-4.9%) participants had AFL-LLN. Thirty-one subjects had COPD-LLN; giving a prevalence of COPD-LLN of (2.4%, 95% CI 1.6-3.3%). In multivariable analysis, male gender (AOR 2.42; 95% CI 1.12-5.20) and lifetime wheezing (AOR 2.88; 95% CI 1.06-7.81) were the determinants of COPD-LLN. Otherwise, male sex (AOR 1.93, 95% CI 1.00-3.73), age 40-59 years (AOR 1.99, 95% CI 1.04-3.81) and lifetime wheezing (AOR 2.65, 95% CI 1.13-6.20) remained as independent determinants of AFL-LLN. CONCLUSIONS: Obstructive lung disease based on more accurate definitions was relatively infrequent in this population. It is important to sensitize the medical staff and the general public about this condition which should be actively investigated in individuals aged 40 years and above.

Determinants of Restrictive Spirometric Pattern in a Sub-Saharan Urban Setting: A Cross-sectional Population-based Study.

BACKGROUND: Restrictive spirometric pattern is a risk factor for all-cause and cause-specific mortality. OBJECTIVE: We assessed the prevalence of restrictive pattern and investigated its determinants in a major sub-Saharan Africa city. METHODS: Participants were adults (≥ 19 years) who took part in a population-based survey in Yaounde (Cameroon) between December 2013 and April 2014. Restrictive pattern was based on a FVC below the lower limit of the normal (LLN) and a ratio forced expiratory volume in one second (FEV1)/FVC ≥ LLN (LLN-based restrictive pattern) or a FVC <80% and FEV1/FVC ≥ LLN (fixed cut-off based restrictive pattern). Determinants were investigated by logistic regressions. RESULTS: In all, 1003 participants [514 (51.2%) women] with a mean age of 33.7 years were included. The prevalence of restrictive pattern was 18.8% (95%CI: 16.6-21.2) based on LLN and 15.0% (13.0-17.2) based on fixed cut-off. LLN-based restrictive pattern was mild in 148 (78.3%) subjects, moderate in 35 (18.5%) and severe in 6 (3.2%). Determinants of LLN-based restrictive pattern were age ≥ 60 years [adjusted odds ratio 2.90 (95%CI 1.46-5.77), p=0.002), history of pulmonary tuberculosis [3.81(1.42-10.20), p=0.008], prevalent heart diseases [3.81 (1.20-12.12), p=0.024] and underweight [5.15(1.30-20.39), p=0.020]. Determinants were largely similar with slightly different effect sizes for fixed cut-off based restrictive pattern. CONCLUSION: Restrictive pattern was very frequent in this city. CLINICAL IMPLICATIONS: These results enhance the needs to increase the efforts to prevent and control tuberculosis, cardiovascular diseases and underweight in this setting.

Planned Health Care Non-Attendance and Asthma Control among Asthma Patients in Real Life Setting in an African Country: a Prospective Cohort Study

BACKGROUND: Compliance with scheduled medical visit is an indirect indicator of the adherence to treatment.The aim of this study was to determine the incidence of non-compliance with scheduled medical visits and investigate the predictors and relationship with disease control among patient with asthma in the sub-Saharan African setting. METHODS: We conducted a prospective study between January 2012 and August 2013. All patients with asthma receiving care at the Yaounde Jamot Hospital and CEDIMER medical practice were included. Planned medical visit occurred at month one; three; six and twelve following baseline evaluation. Regression models were employed to investigate the predictors of non-compliance. RESULTS: 186 patients [121 (65.1%) being female] were included. Their median age (25th-75th percentiles) was 35.5 (20.0-52.3) years. A total of 67 (36%) failed to attend at least one of the scheduled visits. The proportion of patients who failed to comply with scheduled visits was 48.4%; 68.8%; 73.5% and 79.5% at month one; three; six and twelve respectively. The accompanying rates of unacceptable asthma control were 17.2%; 24.4% and 20.8% respectively at three; six and twelve months of follow-up. Inadequate asthma control at baseline was the main predictor of non-compliance with medical visits; with adjusted odds ratio ranging from 2.00 to 4.67. Furthermore; non-sensitisation to non-pollinic aeroallergens was associated with 2.79 (95%CI 1.58-6.07) risk of non-compliance at one month of follow-up. CONCLUSION: Targeting education of patients with poorly controlled disease at baseline can potentially improve adherence to medical visit and anti-asthmatic treatments and outcomes of care

Prevalence of asthma and allergic rhinitis among adults in Yaounde, Cameroon.

BACKGROUND: Population-based estimates of asthma and allergic rhinitis in sub-Saharan African adults are lacking. We assessed the prevalence and determinants of asthma and allergic rhinitis in urban adult Cameroonians. METHODS: A community-based survey was conducted from December 2013 to April 2014 among adults aged 19 years and above (N = 2,304, 57.3% women), selected through multilevel stratified random sampling across all districts of Yaounde (Capital city). Internationally validated questionnaires were used to investigate the presence of allergic diseases. Logistic regressions were employed to investigate the determinants of allergic conditions. RESULTS: Prevalence rates were 2.7% (95% CI: 2.1-3.4) for asthma-ever, 6.9% (5.9-7.9) for lifetime wheezing, 2.9% (92.2-3.6) for current wheezing and 11.4% (10.1-12.7) for self-reported lifetime allergic rhinitis; while 240 (10.4%) participants reported current symptoms of allergic rhinitis, and 125 (5.4%) had allergic rhino-conjunctivitis. The prevalence of current asthma medication use and self-reported asthma attack was 0.8 (0.4-1.2) and 1 (0.6-1.4) respectively. Multivariable adjusted determinants of current wheezing were signs of atopic eczema [2.91 (1.09-7.74)] and signs of allergic rhinitis [3.24 (1.83-5.71)]. Age group 31-40 years [0.27(0.09-0.78), p = 0.016] was an independent protective factor for wheezing. Determinants of current rhinitis symptoms were active smoking [2.20 (1.37-3.54), p<0.001], signs of atopic eczema [2.84 (1.48-5.46)] and current wheezing [3.02 (1.70-5.39)]. CONCLUSION: Prevalence rates for asthma and allergic rhinitis among adults in this population were at the lower tails of those reported in other regions of the world. Beside the classical interrelation between allergic diseases found in this study, active smoking was an independent determinant of allergic rhinitis symptoms. Nationwide surveys are needed to investigate regional variations.

Perennial aeroallergens sensitisation and risk of asthma in African children and adolescents: a case-control study.

OBJECTIVES: The distribution and impact of various aeroallergens on asthma occurrence vary across regions. We investigated the association between sensitisation to perennial aeroallergens and asthma risk in children and adolescents in Yaounde, Cameroon. METHODS: This was a case-control study involving children and adolescents with asthma (cases) vs. non-allergic counterparts (controls). Children/adolescents with doctor-diagnosed asthma were included over a period of 30 months, and controls were selected from the community through random sampling. Logistic regression models were used to relate perennial aeroallergens sensitisation with asthma. RESULTS: The asthma and control groups included, respectively, 151 and 372 participants, with no sex ratio difference. The mean age (standard deviation) was 11.9 (4.4) years in cases and 11.3 (3.7) years in controls. The prevalence of sensitisation to any aeroallergen (cases vs. controls) was 76.8% (116/151) and 32.3% (120/372), p < 0.001. Sensitisation to mites was found in 104 (68.9%) cases vs. 56 (15.1%) controls, p < 0.001. In multivariable analysis, sensitisation to Alternaria alternata, Blattella germanica and dander (cat and dog) was not associated with asthma. However, sensitisation to mites was significantly associated with asthma. Odds ratios (95% CI) for sensitisation to Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis in relation with asthma were 7.28 (3.75-14.15), 2.65 (1.27-5.45) and 3.23 (1.68-6.21), respectively. CONCLUSIONS: Sensitisation to mites was the main perennial allergenic factor associated with asthma in children and adolescents in this setting. This has application for the selection of patients with asthma who could benefit from the control of exposure to mites and specific immunotherapy.