HPV vaccination in Africa in the COVID-19 era: a cross-sectional survey of healthcare providers' knowledge, training, and recommendation practices.

Introduction: Although the burden of cervical cancer in Africa is highest, HPV vaccination coverage remains alarmingly low in this region. Providers' knowledge and recommendation are key drivers of HPV vaccination uptake. Yet, evidence about providers' knowledge and recommendation practices about the HPV vaccine against a backdrop of emerging vaccine hesitancy fueled by the COVID-19 pandemic is lacking in Africa. Methods: A cross-sectional study was conducted in 2021-2022 among healthcare providers involved in cervical cancer prevention activities in Africa. They were invited to report prior training, the availability of the HPV vaccine in their practice, whether they recommended the HPV vaccine, and, if not, the reasons for not recommending it. Their knowledge about the HPV vaccine was assessed through self-reporting (perceived knowledge) and with three pre-tested knowledge questions (measured knowledge). Results: Of the 153 providers from 23 African countries who responded to the survey (mean age: 38.5 years, SD: 10.1), 75 (54.0%) were female and 97 (63.4%) were based In countries with national HPV immunization programs. Overall, 57 (43.8%) reported having received prior training on HPV vaccine education/counseling, and 40 (37.4%) indicated that the HPV vaccine was available at the facility where they work. Most respondents (109, 83.2%) reported recommending the HPV vaccine in their practice. Vaccine unavailability (57.1%), lack of effective communication tools and informational material (28.6%), and need for adequate training (28.6%) were the most commonly reported reasons for not recommending the HPV vaccine. While 63 providers (52.9%) reported that their knowledge about HPV vaccination was adequate for their practice, only 9.9% responded correctly to the 3 knowledge questions. Conclusion: To increase HPV vaccination coverage and counter misinformation about this vaccine in Africa, adequate training of providers and culturally appropriate educational materials are needed to improve their knowledge of the HPV vaccine and to facilitate effective communication with their patients and the community.

Acceptability of test and treat with doxycycline against Onchocerciasis in an area of persistent transmission in Massangam Health District, Cameroon.

The main onchocerciasis elimination strategy is annual Community-Directed Treatment with ivermectin (CDTi). However, as a response to persistent high infection prevalence in Massangam Health District in Cameroon, two rounds of alternative treatments including biannual CDTi, ground larviciding and test and treat with doxycycline (TTd) were implemented. This led to a significant prevalence reduction from 35.7% to 12.3% (p<0.001) as reported by Atekem and colleagues. Here we report on the acceptability of TTd component based on qualitative and quantitative data. The TTd involved microscopic examination for microfilaria in skin biopsy and those infected were offered doxycycline 100 mg daily for 35 days by community-directed distributors (CDDs). Participation level was significantly high with 54% of eligible population (age > 8, not pregnant, not breastfeeding, not severely ill,) participating in the test in each round, increasing to 83% over the two rounds. Factors associated with non-participation included mistrust, being female; being younger than 26 years; short stay in the community; and belonging to semi-nomadic sub population due to their remote and disperse settlement, discrimination, their non selection as CDD, and language and cultural barriers. Treatment coverage was high -71% in round 1 and 83% in round 2. People moving away between testing and treatment impacted treatment coverage. Some participants noted mismatch between symptoms and test result; and that ivermectin is better than doxycycline, while others favoured doxycycline. CDD worried about work burden with unmatching compensation. Overall, TTd participation was satisfactory. But can be improved through reinforcing sensitisation, reducing time between test and treatment; combining TTd and CDTi in one outing; augmenting CDDs compensation and/or weekly visit; exploring for frequently excluded populations and adapting strategies to reach them; and use of a sensitive less invasive test.

Impact of short-term discontinuation of ivermectin-based chemoprevention on onchocerciasis transmission in endemic settings with long history of mass drug administration.

BACKGROUND: The control of onchocerciasis currently relies on annual distribution of single dose ivermectin. Because ivermectin has minimal effects on the adult parasite, mass drug administration (MDA) campaigns against onchocerciasis require at least 15 years of annual uninterrupted ivermectin distribution. Mathematical models have predicted that short-term disruption of MDA (as was seen during COVID-19) could impacted the microfilaridermia prevalence depending on the pre-control endemicity and the histories of treatment, requiring corrective measures (such as biannual MDA) to mitigate the effect on onchocerciasis elimination. Field evidence supporting this prediction, however, has yet to be gathered. This study aimed to assess the impact of ~2 years disruption of MDA on onchocerciasis transmission indicators. METHODOLOGY: A cross-sectional survey was carried out in 2021 in seven villages of Bafia and Ndikinimeki, two health districts located in the Centre Region, Cameroon, where MDA has been ongoing for two decades, but interrupted in 2020 as a response to the COVID-19 pandemic. Volunteers aged 5 years and above were enrolled for clinical and parasitological examinations for onchocerciasis. Data were compared with pre-COVID-19 prevalence and intensity of infection from the same communities to measure changes over time. PRINCIPAL FINDINGS: A total of 504 volunteers (50.3% males), aged 5-99 years (Median: 38; IQR: 15-54) was enrolled in the two health districts. The overall prevalence of microfilaridermia in 2021 was similar in Ndikinimeki health district (12.4%; 95% CI: 9.7-15.6) and Bafia health district (15.1%; 95% CI: 11.1-19.8) (p-value = 0.16). Microfilaridermia prevalences were either similar between 2018 and 2021 in the communities of Ndikinimeki health district (19.3% vs 12.8% (p = 0.057) for Kiboum 1; and 23.7% vs 21.4% (p = 0.814) for Kiboum 2), or higher in 2019 compared to 2021 in the communities of Bafia health district (33.3% vs 20.0% (p = 0.035) for Biatsota). The mean microfilarial densities in these communities dropped from 5.89 (95% CI: 4.77-7.28) mf/ss to 2.4 (95% CI: 1.68-3.45) mf/ss (p-value < 0.0001), and from 4.81 (95% CI: 2.77-8.31) mf/ss to 4.13 (95% CI: 2.49-6.86) mf/ss (p-value < 0.02) in Bafia and Ndikinimeki health districts, respectively. Community Microfilarial Load (CMFL) dropped from 1.08-1.33 mf/ss in 2019 to 0.052-0.288 mf/ss in 2021 in Bafia health district while remaining stable in the Ndikinimeki health district. CONCLUSION/SIGNIFICANCE: The continued decline in prevalence and CMFL observed ~2 years after MDA disruption is consistent with mathematical predictions (ONCHOSIM) and shows that additional efforts and resources are not needed to mitigate the effects of short-term MDA disruption in highly endemic settings prior to intervention with long treatment histories.

Development, Implementation, and Evaluation of a Distance Learning and Telementoring Program for Cervical Cancer Prevention in Cameroon.

Importance: Although Africa has the highest burden of cervical cancer in the world, educational resources to achieve the 90-70-90 targets set by the World Health Organization in its strategy to eliminate cervical cancer are lacking in the region. Objectives: To adapt, implement, and evaluate the Project Extension for Community Health Care Outcomes (ECHO), an innovative learning tool, to build capacity of clinicians to better incorporate new evidence-based guidelines into cervical cancer control policies and clinical practices. Design, Setting, and Participants: This cross-sectional study assessed knowledge and practices of clinicians and support staff regarding cervical cancer prevention and control and compared them among respondents who had attended Project ECHO sessions (prior ECHO attendees) with those who had not but were planning on attending in the near future (newcomers) as part of the Cameroon Cervical Cancer Prevention Project ECHO. Satisfaction of prior ECHO attendees was also evaluated. Data were analyzed from January to March 2022. Main Outcomes and Measures: Main outcomes were practices and knowledge regarding cervical cancer education and prevention and preinvasive management procedures compared among prior ECHO attendees and newcomers. Results: Of the 75 participants (mean [SD] age, 36.4 [10.0] years; 65.7% [95% CI, 54.3%-77.1%] women) enrolled in this study, 41 (54.7%; 95% CI, 43.1%-66.2%) were prior ECHO attendees, and most were clinicians (55 respondents [78.6%; 95% CI, 68.7%-88.4%]). Overall, 50% (95% CI, 37.8%-62.2%) of respondents reported performing cervical cancer screening with visual inspection of the cervix after application of acetic acid (VIA) and/or visual inspection of the cervix after application of Lugol's iodine (VILI), 46.3% (95% CI, 34.0%-58.5%) of respondents reported performing human papillomavirus (HPV) testing, and 30.3% (95% CI, 18.9%-41.7%) of respondents reported performing cervical cytological examination in their practices, Approximately one-fourth of respondents reported performing cryotherapy (25.4% [95% CI, 14.7%-36.1%]), thermal ablation (27.3% [95% CI, 16.2%-38.3%]) or loop electrosurgical excisional procedure (LEEP, 25.0% [95% CI, 14.4%-35.6%]) for treatment of preinvasive disease. The clinical use of many of these screening and treatment tools was significantly higher among prior ECHO attendees compared with newcomers (VIA/VILI: 63.2% [95% CI, 47.4%-78.9%] vs 33.3% [95% CI, 16.0%-50.6%]; P = .03; cryotherapy: 40.5% [95% CI, 24.3%-56.8%] vs 6.7% [95% CI, 0.0%-15.8%]; P = .002; thermal ablation: 43.2% [95% CI, 26.9%-59.6%] vs 6.9% [95% CI, 0.0%-16.4%]; P = .002). Knowledge about cervical cancer education, prevention, and management procedures was satisfactory in 36.1% (95% CI, 23.7%-48.5%) of respondents; this proportion was significantly higher among prior ECHO attendees (53.8% [95% CI, 37.7%-69.9%]) compared with newcomers (4.5% [95% CI, 0.0%-13.5%]; P < .001). Approximately two-thirds of participants (68.8% [95% CI, 51.8%-85.8%]) reported that they had applied knowledge learned in our ECHO sessions to patient care in their practice or adopted best-practice care through their participation in this ECHO program. Conclusions and Relevance: These findings suggest that the Project ECHO e-learning and telementoring program was associated with improved skills for clinicians and support staff and enhanced quality of care for patients. In the COVID-19 era and beyond, reinforced efforts to strengthen cervical cancer knowledge and best practices through distance learning and collaboration are needed.

Factors associated with variation in single-dose albendazole pharmacokinetics: A systematic review and modelling analysis.

BACKGROUND: Albendazole is an orally administered anti-parasitic medication with widespread usage in a variety of both programmatic and clinical contexts. Previous work has shown that the drug's pharmacologically active metabolite, albendazole sulfoxide, is characterised by substantial inter-individual pharmacokinetic variation. This variation might have implications for the efficacy of albendazole treatment, but current understanding of the factors associated with this variation remains incomplete. METHODOLOGY/PRINCIPAL FINDINGS: We carried out a systematic review to identify references containing temporally disaggregated data on the plasma concentration of albendazole and/or (its pharmacologically-active metabolite) albendazole sulfoxide following a single oral dose. These data were then integrated into a mathematical modelling framework to infer albendazole sulfoxide pharmacokinetic parameters and relate them to characteristics of the groups being treated. These characteristics included age, weight, sex, dosage, infection status, and whether patients had received a fatty meal prior to treatment or other drugs alongside albendazole. Our results highlight a number of factors systematically associated with albendazole sulfoxide pharmacokinetic variation including age, existing parasitic infection and receipt of a fatty meal. Age was significantly associated with variation in albendazole sulfoxide systemic availability and peak plasma concentration achieved; as well as the clearance rate (related to the half-life) after adjusting for variation in dosage due to differences in body weight between children and adults. Receipt of a fatty meal prior to treatment was associated with increased albendazole sulfoxide systemic availability (and by extension, peak plasma concentration and total albendazole sulfoxide exposure following the dose). Parasitic infection (particularly echinococcosis) was associated with altered pharmacokinetic parameters, with infected populations displaying distinct characteristics to uninfected ones. CONCLUSIONS/SIGNIFICANCE: These results highlight the extensive inter-individual variation that characterises albendazole sulfoxide pharmacokinetics and provide insight into some of the factors associated with this variation.

Individuals living in an onchocerciasis focus and treated three-monthly with ivermectin develop fewer new onchocercal nodules than individuals treated annually.

BACKGROUND: Little information is available on the effect of ivermectin on the third- and fourth-stage larvae of Onchocerca volvulus. To assess a possible prophylactic effect of ivermectin on this parasite, we compared the effects of different ivermectin regimens on the acquisition of onchocercal nodules. METHODS: We analyzed data from a controlled randomized clinical trial of ivermectin conducted in the Mbam Valley (Cameroon) between 1994 and 1998 in a cohort of onchocerciasis infected individuals. The number of nodules that appeared between the start and the end of the clinical trial was analyzed, using ANOVA and multivariable Poisson regressions, between four treatment arms: 150 µg/kg annually, 800 µg/kg annually, 150 µg/kg 3-monthly, and 800 µg/kg 3-monthly. RESULTS: The mean number of nodules that appeared during the trial was reduced by 17.7% in subjects treated 3-monthly compared to those treated annually (regardless of the dose). Poisson regression model, adjusting on subject's age and weight, initial number of nodules and intensity of O. volvulus infection in his village of residence, confirmed that the incidence of new nodules was reduced in 3-monthly treatment arms compared to annually treatment arms, and that the dosage of ivermectin does not seem to influence this effect. Furthermore, the number of newly acquired nodules was positively associated with the initial number of nodules. Analysis of disappearance of nodules did not show any significant difference between the treatment groups. CONCLUSIONS: To our knowledge, these results suggest for the first time in humans, that ivermectin has a partial prophylactic effect on O. volvulus. Three-monthly treatment seems more effective than annual treatment to prevent the appearance of nodules.

Prevalence of major cardiovascular disease risk factors among a group of sub-Saharan African young adults: a population-based cross-sectional study in Yaoundé, Cameroon.

OBJECTIVE: To determine the prevalence estimates of some major risk factors for cardiovascular disease (CVD) in a young adult-aged population living in Yaoundé, Cameroon. DESIGN: A cross-sectional study held from May to July 2017. SETTING: PARTICIPANTS: Students aged 18-35 years, with no known history of CVD, found at the campus during recruitment and who voluntarily agreed to be included in the study. PRIMARY AND SECONDARY OUTCOME MEASURES: Data were collected on personal and family history as well as lifestyle and nutritional habits; anthropometric parameters and blood pressure were also measured. Prevalence rates were calculated with their respective 95% CI. RESULTS: Overall, 931 participants (53.8% males) were included, with a median age of 23 years (IQR 21-25). The prevalence estimates for some major CVD risk factors were: 3.1% (95% CI 2.0 to 4.2) for family history of heart attack, 6.3% (95% CI 4.7 to 7.9) for family history of stroke, 26.7% (95% CI 23.9 to 29.5) for hazardous alcohol consumption, 0.9% (95% 0.3 to 1.5) for current tobacco smoking, 27.6% (95% CI 24.7 to 30.5) for secondhand smoking, 88.9% (95% CI 86.9 to 90.9) for physical inactivity, 99.0% (95% CI 98.4 to 99.6) for inadequate fruits and/or vegetables consumption, 39.8% (95% CI 36.7 to 42.9) for self-reported anxiety, 49.2% (95% CI 46.0 to 52.4) for self-reported depression, 22.1% (95% CI 19.4 to 24.8) for overweight, 3.9% (95% CI 2.7 to 5.1) for obesity, 14.4% (95% CI 12.1 to 16.7) for abdominal obesity, 14.5% (95% CI 12.2 to 16.8) for excess body fat mass, 30.0% (95% CI 27.1 to 32.9) for suspected prehypertension and 2.8% (95% CI 1.7 to 3.9) for suspected hypertension. CONCLUSION: The prevalence of some major CVD risk factors is high among young adults living in Yaoundé, Cameroon. Therefore, specific actions should be undertaken in this population to mitigate the upcoming burden of CVD. Accordingly, younger-aged adult populations should be encouraged and accompanied to practice physical activity, eat healthily, and stop or avoid smoking and/or hazardous alcohol consumption.

Identification and characterization of the Onchocerca volvulus Excretory Secretory Product Ov28CRP, a putative GM2 activator protein.

Onchocerca volvulus is the nematode pathogen responsible for human onchocerciasis also known as "River blindness", a neglected tropical disease that affects up to 18 million people worldwide. Helminths Excretory Secretory Products (ESPs) constitute a rich repertoire of molecules that can be exploited for host-parasite relationship, diagnosis and vaccine studies. Here, we report, using a range of molecular techniques including PCR, western blot, recombinant DNA technology, ELISA, high performance thin-layer chromatography and mass spectrometry that the 28 KDa cysteine-rich protein (Ov28CRP) is a reliable component of the O. volvulus ESPs to address the biology of this parasite. We showed that (1) Ov28CRP is a putative ganglioside GM2 Activator Protein (GM2AP) conserved in nematode; (2) OvGM2AP gene is transcriptionally activated in all investigated stages of the parasitic life cycle, including larval and adult stages; (3) The full-length OvGM2AP was detected in in-vitro O. volvulus ESPs of adult and larval stages; (4) the mass expressed and purified recombinant OvGM2AP purified from insect cell culture medium was found to be glycosylated at asparagine 173 and lacked N-terminal signal peptide sequence; (5) the recombinant OvGM2AP discriminated serum samples of infected and uninfected individuals; (6) OvGM2AP competitively inhibits MUG degradation by recombinant ß-hexosaminidase A but not MUGS, and could not hydrolyze the GM2 to GM3; (7) humoral immune responses to the recombinant OvGM2AP revealed a negative correlation with ivermectin treatment. Altogether, our findings suggest for the first time that OvGM2AP is an antigenic molecule whose biochemical and immunological features are important to gain more insight into our understanding of host-parasite relationship, as well as its function in parasite development at large.

A possible case of spontaneous Loa loa encephalopathy associated with a glomerulopathy.

It is well known that renal and neurological complications may occur after antifilarial treatment of patients infected with Loa loa. Conversely, spontaneous cases of visceral complications of loiasis have been rarely reported. A 31-year-old Congolese male patient who had not received any antifilarial drug developed oedema of the lower limbs, and then transient swellings of upper limbs. Two months after, he developed troubles of consciousness within several hours. At hospital, the patient was comatose with mild signs of localization. Laboratory tests and an abdominal echography revealed a chronic renal failure due to a glomerulopathy. Three weeks after admission, Loa microfilariae were found in the cerebrospinal fluid, and a calibrated blood smear revealed a Loa microfilaraemia of 74,200 microfilariae per ml. The level of consciousness of the patient improved spontaneously, without any specific treatment, but several days after becoming completely lucid, the patient died suddenly, from an undetermined cause. Unfortunately, no biopsy or autopsy could be performed. The role of Loa loa in the development of the renal and neurological troubles of this patient is questionable. But the fact that such troubles, which are known complications of Loa infection, were found concomitantly in a person harbouring a very high microfilarial load suggests that they might have been caused by the filarial parasite. In areas endemic for loiasis, examinations for a Loa infection should be systematically performed in patients presenting an encephalopathy or a glomerulopathy.

T helper cell type 2 responsiveness predicts future susceptibility to gastrointestinal nematodes in humans.

Some humans are persistently more susceptible to gastrointestinal nematodes than others. Here, for the first time, susceptibility to reinfection has been linked to host cytokine responses. Ascaris lumbricoides and Trichuris trichiura abundance was assessed immediately before and 8-9 months after deworming in a Cameroonian population (starting n=191). Profiles of whole-blood cytokine responses to parasite antigens (for interleukin [IL]-5, IL-13, IL-10, IL-12p40, tumor necrosis factor- alpha , and interferon- gamma), assayed before treatment, were significantly related both to an overall measure of host susceptibility and to susceptibility to reinfection. Significant effects were primarily due to a negative association between IL-13 and IL-5 responses and infection. Persistently susceptible individuals were, therefore, characterized by a weak T helper cell type 2 response. The apparent plasticity of age-specific cytokine response-worm abundance relationships between different populations is also discussed.

A comparison of cellular and humoral immune responses to trichuroid derived antigens in human trichuriasis.

Individuals, residing in a region highly endemic for Trichuris trichiura, were examined for cytokine and proliferative responses to T. trichiura worm homogenate (TtAg), T. trichiura excretory/secretory products (TtES) and the equivalent antigenic preparations from the murine whipworm, Trichuris muris. Serum antibody levels against TtAg, T. muris worm homogenate and T. muris ES products were also studied. Measurable levels of immunoglobulin (Ig)G1, IgG4, IgA and IgE against T. muris antigens were detected, indicating a degree of conservation of epitopes between antigens derived from both species. Although levels of interleukin (IL)-4, IL-10, IL-13, tumour necrosis factor (TNF)-alpha and proliferative responses produced were comparable between homogenate antigens of either species and ES antigens of either species, a markedly different cellular response was observed in cultures stimulated with homogenate antigens compared to ES antigens. ES antigens preferentially induced IL-10 (P > 0.001) and TNF-alpha (P > 0.001) production, whereas levels of IL-4 (P > 0.001), IL-13 (P > 0.001) and proliferative responses (P > 0.001) were greater in cultures stimulated with whole worm extracts. Our findings suggest that T. muris preparations could be used as an alternative to T. trichiura proteins as a source of antigens in ex vivo cultures and that ES products stimulate a distinct immune response compared to somatic antigens.

Age- and infection intensity-dependent cytokine and antibody production in human trichuriasis: the importance of IgE.

The cytokine and antibody response to Trichuris trichiura infection was determined for 96 persons living in an area where the parasite is highly endemic and infection exhibits a convex age intensity profile. In response to stimulation with T. trichiura antigen, a small proportion of the study group produced interleukin (IL)-4 (7%), IL-9 (5%), and IL-13 (17%). A larger proportion produced IL-10 (97%), tumor necrosis factor (TNF)-alpha (93%), and interferon (IFN)-gamma (32%). The levels of TNF-alpha (P =.016) and IFN-gamma (P =.012) significantly increased with age, suggesting a switch to a more chronic infection phenotype. The predominant parasite-specific antibodies produced were IgG1, IgG4, IgA, and IgE. Unlike the IgG subclasses and IgA, parasite-specific IgE correlated negatively with infection intensity, as defined by egg output (P =.008), and positively with host age (P =.010). These findings suggest a mixed cytokine response in trichuriasis and an IgE-associated level of protection.