SARS-CoV-2 Neutralizing Antibodies in Three African Countries Following Multiple Distinct Immune Challenges.

BACKGROUND: The COVID-19 pandemic has affected Madagascar, Cameroon, and the Central African Republic (CAR), with each experiencing multiple waves by mid-2022. This study aimed to evaluate immunity against SARS-CoV-2 strains Wuhan (W) and BA.2 (BA.2) among healthcare workers (HCWs) in these countries, focusing on vaccination and natural infection effects. METHODS: HCWs' serum samples were analyzed for neutralizing antibodies (nAbs) against W and BA.2 variants, with statistical analyses comparing responses between countries and vaccination statuses. RESULTS: Madagascar showed significantly higher nAb titers against both strains compared to CAR and Cameroon. Vaccination notably increased nAb levels against W by 2.6-fold in CAR and 1.8-fold in Madagascar, and against BA.2 by 1.6-fold in Madagascar and 1.5-fold in CAR. However, in Cameroon, there was no significant difference in nAb levels between vaccinated and unvaccinated groups. CONCLUSION: This study highlights the complex relationship between natural and vaccine-induced immunity, emphasizing the importance of assessing immunity in regions with varied epidemic experiences and low vaccination rates.

High seroprevalence of severe acute respiratory syndrome coronavirus 2 among healthcare workers in Yaoundé, Cameroon after the first wave of Covid-19 pandemic and associated factors.

BACKGROUND: Healthcare workers (HWs) are at a high risk of exposure to emerging health threats. Following the first wave of the coronavirus disease 2019 pandemic in Cameroon, we explored the presence and persistence of naturally acquired antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the factors associated with seropositivity in HWs. METHODS: Staff at two referral hospitals in Yaoundé or two Health District Hospitals in Obala and Mbalmayo were included in a 6-month prospective cohort analysis or cross-sectional survey, respectively. Seroprevalence and associated factors were determined, and Kaplan-Meier curves and Cox proportional hazards models were used to assess antibody persistence or positive seroconversion over time. RESULTS: From August 2020 to March 2021, 426 HWs (median age: 31 years, interquartile range: 27-37 years; 66.4% female) were enrolled. The overall seroprevalence of anti-SARS-CoV-2 antibodies was 54.0% (95% confidence interval [CI]: 49.1-58.8) and was significantly different between study sites (p = 0.04). Of the 216 HWs included in the 6-month cohort, 109 (50.5%) HWs were seropositive at inclusion; the probability of persistent antibodies or of becoming seropositive was 93.8% (95% CI: 84.2-100) and 78.9% (95% CI: 61.7-88.4), respectively. Seroconversion was associated with study site and occupation but not with infection prevention and control (IPC) practices. CONCLUSIONS: We observed high seroprevalence of SARS-CoV-2 antibody and seroconversion among HWs associated with occupational risk. This suggests low compliance to the COVID-19 control measures. Continued training and implementation of IPC measures and accelerated preparedness are needed to better tackle future threats.

Diagnosing disseminated histoplasmosis in advanced HIV/AIDS disease in Cameroon using a point of care lateral flow assay.

Histoplasmosis is an AIDS-defining opportunistic infection. Disseminated histoplasmosis (DH) can be fatal without early diagnosis and treatment initiation. We present one confirmed and three probable cases of DH in advanced HIV/AIDS disease patients diagnosed using OIDx Histoplasma LFA in Yaoundé, Cameroon. Four women with HIV but unknown CD4 count presented with asthenia, weight loss, productive cough, and fever (39°C) as common symptoms for at least 3 weeks. Two of the patients had skin lesions. These included facial papules, macules, and umbilicated vesicles scattered over the trunk and limbs. These were diffuse lesions which were purulent, itching, and papillomatous lesions with a necrotic centre, and one patient had a right forearm ulcer. We performed the Histoplasma antigen tests using the OIDx Histo LFA, and they were strongly positive in all four patients. Histopathology in skin biopsy allowed identification of the species as Histoplasma capsulatum var capsulatum in one patient. In this same patient, Pseudomonas aeruginosa and Proteus mirabilis were cultured from the forearm ulcer. This patient later commenced antibiotics (Levofloxacin 500 mg) and oral itraconazole (800 mg/day) with immediate improvement. Unfortunately, the other three patients could not access itraconazole, were discharged and lost to follow-up. Early diagnosis and treatment are essential for the management of DH. LFA is a test that can be set up in any setting with limited resource. Access to this can be a major advance in the diagnosis of histoplasmosis in resource-limited settings.

Implementation and evaluation of a therapeutic patient education programme during a clinical trial in Yaoundé, Cameroon - Trial ANRS-12286/MOBIDIP.

OBJECTIVES: High adherence is needed to maintain antiretroviral therapy efficacy. Few attempts at therapeutic patient education (TPE) have been made in sub-Saharan Africa. We describe patients' achievements before intervention and identified needs, TPE programme implementation and evaluation, and patients' satisfaction. METHODS: The TPE programme was proposed to patients in the ANRS-12286/MOBIDIP trial. Beforehand, a directory of competences to manage HIV infection was designed. Patients' HIV-related knowledge and skills assessment was realised, leading to an educational contract. Evaluation was performed using a standardised collection form and a satisfaction survey. RESULTS: Of 154 patients, 146 underwent TPE. During a median of 1.8 years, 47% of patients had ≥3 consultations. Educational assessment revealed limited knowledge about HIV disease. Conversely, patients had frequently managed issues of adherence or disclosure. A median of 12 objectives were considered per patient, and 75% were attained. Objectives from the cognitive domain were less frequently attained. Patients appeared satisfied with the intervention: more emphasis was placed on psycho-affective aspects or experience-sharing than on the acquisition of knowledge. CONCLUSION: Active listening, know-how and a space for discussion appear more important for patients than knowledge on disease or treatments. PRACTICE IMPLICATIONS: In HIV care, the directory of learning objectives should be revised to include more objectives concerning practical skills for disease management.

Incidence of infectious morbidity events after second-line antiretroviral therapy initiation in HIV-infected adults in Yaoundé, Cameroon.

BACKGROUND: Since antiretroviral therapy (ART), HIV-infected individuals experience mainly non-AIDS-related conditions, among which infectious events are prominent. We aimed to estimate incidence and describe overall spectrum of infectious events, including all grade events, among HIV-1-infected adults failing first-line ART in Yaoundé, Cameroon. METHODS: All patients from Cameroon enrolled in the second-line ART 2LADY trial (ANRS12169) were included in this secondary analysis. Medical files were reviewed with predefined criteria for diagnosis assessment. Incidence rates (IR) were estimated per 100 person-years (% PY). RESULTS: A total of 302 adult patients contributing 840 PY experienced 596 infectious events (IR 71% PY). Only 29 (5%) events were graded as severe. Most frequent infections were upper respiratory tract infections (15% PY), diarrhoea (9% PY) and malaria (9% PY). A total of 369 (62%) infections occurred during the first year (IR 130% PY) followed by a persistent lower incidence during the following 3 years. Higher IR were observed in patients with CD4+ T-cell count <200 cells/mm3 for all infectious events except for mycobacterial and parasitic infections. IR of viral, bacterial and parasitic infectious events were lower in case of co-trimoxazole use in patients with CD4+ T-cell count <200 cells/mm3. CONCLUSIONS: Infectious events are common and mainly occur during the first year after treatment initiation. Second-line ART initiation had a positive impact on the entire spectrum of infectious morbidity.

Characteristics of patients co-infected with HIV at the time of inpatient tuberculosis treatment initiation in Yaoundé, Cameroon: a tertiary care hospital-based cross-sectional study.

BACKGROUND: Knowledge of the characteristics of patients co-infected with tuberculosis (TB) and human immunodeficiency virus (HIV) when TB treatment is initiated would allow clinicians to improve care and help policy-makers develop relevant and realistic guidelines. The aim of this study was to describe socio-demographic, clinical, and laboratory characteristics of TB/HIV co-infected patients starting inpatient TB treatment in Yaoundé, Cameroon. METHODS: We conducted a retrospective cross-sectional study, collecting data from medical records of HIV-infected patients with TB, aged 15 years old or more, hospitalized in the Infectious Diseases Unit of the Yaoundé Central Hospital, Cameroon from January 1, 2006 to June 30, 2013. RESULTS: The mean age of 337 patients meeting study inclusion criteria was 39.3 years. More than half were female (53.4%). Most (89.3%) resided in urban areas, 44.2% had a secondary education, and 46.0% were married. The majority was receiving co-trimoxazole prophylaxis (79.5%), and two thirds were taking antiretroviral therapy (67.4%). The mean duration of known HIV infection before TB treatment was 8.4 months. Most (88.1%) had newly diagnosed TB, rather than relapsed disease. Smear-positive pulmonary TB was documented in a third, (35.3%). Laboratory data revealed a median white blood cell count of 5,100 cells/mm(3) (IQR 3,300-7,990 cells/mm(3)), a median hemoglobin level of 8 g/dl (IQR 7-10 g/dl), and a median CD4 cell count of 102 cells/mm(3) (IQR 33-178 cells/mm(3)). Sex differences in our study included older age in the men (p < 0.001), more of whom were married (p < 0.001) and had achieved a higher level of education (p = 0.042). Men had fewer diagnoses of smear-positive pulmonary TB (p = 0.020). They weighed more than the women (p = 0.001) and had higher hemoglobin levels (p = 0.003). CONCLUSIONS: Suboptimal adherence to WHO treatment recommendations in our Cameroonian study reinforces the importance of prescribing co-trimoxazole in HIV infection and ART for all TB/HIV co-infected persons. We urge that Ministries of Health continue implementing and disseminating guidelines for management of TB/HIV co-infected patients, and we call for measures ensuring that healthcare facilities' stocks of ART and co-trimoxazole are sufficient to meet the need for both.