The burden of stroke in Africa: a glance at the present and a glimpse into the future.

OBJECTIVE: Information on the current burden of stroke in Africa is limited. The aim of this review was to comprehensively examine the current and projected burden of stroke in Africa. METHODS: We systematically reviewed the available literature (PubMed and AJOL) from January 1960 and June 2014 on stroke in Africa. Percentage change in age-adjusted stroke incidence, mortality and disability-adjusted life years (DALYs) for African countries between 1990 and 2010 were calculated from the Global Burden of Diseases (GBD) model-derived figures. RESULTS: Community-based studies revealed an age-standardised annual stroke incidence rate of up to 316 per 100,000 population, and age-standardised prevalence rates of up to 981 per 100,000. Model-based estimates showed significant mean increases in age-standardised stroke incidence. The peculiar factors responsible for the substantial disparities in incidence velocity, ischaemic stroke proportion, mean age and case fatality compared to high-income countries remain unknown. CONCLUSIONS: While the available study data and evidence are limited, the burden of stroke in Africa appears to be increasing.

Age-specific prevalence of human papilloma virus infection among Nigerian women.

BACKGROUND: Inconsistent trends in HPV prevalence by age have been described in Africa. We examined the age prevalence pattern and distribution of 37 HPV-DNA types among urban Nigerian women. METHODS: The study population was a sample of 278 women who presented to cervical cancer screening programs in Abuja, Nigeria, between April and August 2012. Using a nurse administered questionnaire, information on demographic characteristics and risk factors of cervical cancer was collected and samples of cervical exfoliated cells were obtained from all participants. Roche Linear Array HPV Genotyping Test® was used to characterize prevalent HPV and log-binomial regression models were used to examine the association between potential correlates and the prevalence of HPV infection. RESULTS: The mean age (SD) of the women enrolled was 38 (8) years. The overall prevalence of HPV was 37%. HPV 35 was the most prevalent HPV type in the study population. Among women age ≤ 30 years, 52% had HPV infection compared to 23% of those women who were older than 45 years (p = 0.006). We observed a significant linear association between age and the prevalence of HPV infections. The prevalence ratio (PR) and 95% confidence interval (CI) was 2.26 (1.17, 4.34) for any HPV infection, 3.83 (1.23, 11.94) for Group 1 HPV (definite carcinogens), and 2.19 (0.99, 4.84) for Group 2a or 2b HPV (probable or possible carcinogens) types, among women aged 18-30 years, compared to women who were older than 45 years. CONCLUSION: The prevalence of HPV infection was highest among younger women and decreased steadily with age among this population of urban Nigerian women.

Prevalence and correlates of leisure-time physical activity among Nigerians.

BACKGROUND: Physical inactivity levels are rising in many countries with major implications for the prevalence of non-communicable diseases and the general health of the population worldwide. We conducted this study to examine leisure-time physical activity levels among African adults in an urban setting. METHODS: We conducted a cross-sectional study among a random sample of 1,058 adults at a government worksite, in Abuja, an urban Nigerian city. We used log-binomial regression models to estimate the multivariable-adjusted associations of correlates of physical activity. RESULTS: The mean age of the study population was 42 ± 9.3 years, 60% were men and 40% were women. The mean metabolic equivalent hours per week for all the participants was 6.8 ± 7.2. In univariate analysis comparing the lowest to highest tertiles of physical activity, the prevalence ratio (PR) and (95% confidence interval, CI) was 0.95 (0.81-1.11) p = 0.49, comparing women to men; compared to those aged <30 years the PR (95% CI) was 0.70 (0.57-0.86), 0.70 (0.58-0.85) and 0.78 (0.63-0.96) for age 30-39, 40-49 and ≥50 years respectively, p for trend = 0.03; compared to those who were normal weight, the PR was 0.93 (0.79-1.10) and 0.90 (0.74-1.09) for overweight and obese persons respectively, p = 0.26. The PR for age was attenuated to non-significant levels in multivariable analyses. Being married was a statistically significant correlate of higher physical activity levels, the PR comparing unmarried to married persons in multivariate analysis was 0.81 (0.67-0.97), p = 0.03. CONCLUSIONS: More than 80% of urban, professional Nigerian adults do not meet the WHO recommendations of physical activity. Urbanized Africans in this study population had low levels of leisure-time physical activity, independent of age, sex and body-mass index. This has major implications for the prevalence of non-communicable diseases in this population.

Obesity epidemic has emerged among Nigerians.

BACKGROUND: Data from the WHO shows that the prevalence of overweight and obesity increased by ~20% between 2002 and 2010 in Nigeria. We conducted this study to examine the correlates of this fast growing epidemic. METHODS: We conducted a cross-sectional study among a random sample of 1058 adults, who were visitors and staff of a government worksite in Abuja, an urban city in Nigeria. The study participants had varying socio-economic status and a wide range of occupations, including skilled labor and professionals. Log-binomial regression models were used to estimate the multivariable-adjusted associations of potential determinants with the prevalence of overweight and obesity. RESULT: The mean age and body-mass index of the study population were 42 years ± (9.3) and 27 kg/m2 ± (4.8). The overall prevalence of overweight or obesity (body-mass index ≥ 25 kg/m2) was 64% (74% of the women and 57% of the men). For women compared to men, the prevalence ratio (PR) and (95% confidence interval, CI) was 1.24 (95% CI 1.08, 1.43, p = 0.004), for overweight, and 2.54 (95% CI 2.08, 3.10, p = <0.0001), for obesity. Individuals aged 40 - 49 years were more likely to be overweight or obese. The PR for overweight and obesity was 1.45 (95% CI 1.07, 1.97), p for age trend = 0.002 and 8.07(95% CI 3.01, 21.66, p for age trend = <0.0001) for those aged 40 - 49 years, compared with those aged <30 years. Compared with the individuals in the lower socio-economic status, the PR for obesity among those in the middle and high socio-economic statuses, were 1.39 (95% CI 1.13, 1.72) and 1.24 (95% CI 0.97, 1.59) respectively, p for trend = 0.003. CONCLUSION: About two-thirds of urban, professional, high socio-economic status Nigerian adults are either overweight or obese. The prevalence of overweight and obesity among this population of adult Nigerians, is as high as it is in the United Kingdom. Female gender and older age were independent predictors of overweight and obesity; while middle or high socio-economic status were independently associated with obesity.

Understanding the rise in cardiovascular diseases in Africa: harmonising H3Africa genomic epidemiological teams and tools.

Cardiovascular diseases, principally ischaemic heart disease and stroke, are the leading causes of global mortality and morbidity. Together with other non-communicable diseases, they account for more than 60% of global deaths and pose major social, economic and developmental challenges worldwide. In Africa, there is now compelling evidence that the major cardiovascular disease (CVD) risk factors are on the rise, and so are the related fatal and non-fatal sequelae, which occur at significantly younger ages than seen in high-income countries. In order to tackle this rising burden of CVD, the H3Africa Cardiovascular Working Group will hold an inaugural workshop on 30 May 2014 in Cape Town, South Africa. The primary workshop objectives are to enhance our understanding of the genetic underpinnings of the common major CVDs in Africa and strengthen collaborations among the H3Africa teams and other researchers using novel genomic and epidemiological tools to contribute to reducing the burden of CVD on the continent.

Cancer burden among HIV-positive persons in Nigeria: preliminary findings from the Nigerian AIDS-cancer match study.

BACKGROUND: Although Nigeria has a large HIV epidemic, the impact of HIV on cancer in Nigerians is unknown. METHODS: We conducted a registry linkage study using a probabilistic matching algorithm among a cohort of HIV positive persons registered at health facilities where the Institute of Human Virology Nigeria (IHVN) provides HIV prevention and treatment services. Their data was linked to data from 2009 to 2012 in the Abuja Cancer Registry. Match compatible files with first name, last name, sex, date of birth and unique HIV cohort identification numbers were provided by each registry and used for the linkage analysis. We describe demographic characteristics of the HIV clients and compute Standardized Incidence Ratios (SIRs) to evaluate the association of various cancers with HIV infection. RESULTS: Between 2005 and 2012, 17,826 persons living with HIV (PLWA) were registered at IHVN. Their median age (Interquartile range (IQR)) was 33 (27-40) years; 41% (7246/17826) were men and 59% (10580/17826) were women. From 2009 to 2012, 2,029 clients with invasive cancers were registered at the Abuja Cancer Registry. The median age (IQR) of the cancer clients was 45 (35-68) years. Among PLWA, 39 cancer cases were identified, 69% (27/39) were incident cancers and 31% (12/39) were prevalent cancers. The SIR (95% CI) for the AIDS Defining Cancers were 5.7 (4.1, 7.2) and 2.0 (0.4, 3.5), for Kaposi Sarcoma and Cervical Cancer respectively. CONCLUSION: The risk of Kaposi Sarcoma but not Cervical Cancer or Non-Hodgkin's Lymphoma, was significantly increased among HIV positive persons, compared to the general population in Nigeria.

Understanding the Rise in Cardiovascular Diseases in Africa : Harmonising H3Africa Genomic Epidemiological Teams and Tools : Cardiovascular Topic

Cardiovascular diseases; principally ischaemic heart disease and stroke; are the leading causes of global mortality and morbidity. Together with other non-communicable diseases; they account for more than 60 of global deaths and pose major social; economic and developmental challenges worldwide. In Africa; there is now compelling evidence that the major cardiovascular disease (CVD) risk factors are on the rise; and so are the related fatal and non-fatal sequelae; which occur at significantly younger ages than seen in high-income countries. In order to tackle this rising burden of CVD; the H3Africa Cardiovascular Working Group will hold an inaugural workshop on 30 May 2014 in Cape Town; South Africa. The primary workshop objectives are to enhance our understanding of the genetic underpinnings of the common major CVDs in Africa and strengthen collaborations among the H3Africa teams and other researchers using novel genomic and epidemiological tools to contribute to reducing the burden of CVD on the continent

HIV associated high-risk HPV infection among Nigerian women.

BACKGROUND: In developed countries, the incidence of cervical cancer has remained stable in HIV+ women but the prevalence and multiplicity of high-risk HPV (hrHPV) infection, a necessary cause of cervical cancer, appears different comparing HIV+ to HIV- women. Little is known about HIV and HPV co-infection in Africa. METHODS: We enrolled women presenting at our cervical cancer screening program in Abuja, Nigeria between April and August 2012, and collected information on demographic characteristics, risk factors of HPV infection and samples of exfoliated cervical cells. We used Roche Linear Array HPV Genotyping Test® to characterize prevalent HPV and logistic regression models to estimate the association between HIV and the risk of hrHPV infection. RESULTS: There were 278 participants, 54% (151) were HIV+, 40% (111) were HIV-, and 6% (16) had unknown HIV status. Of these, data from 149 HIV+ and 108 HIV- women were available for analysis. The mean ages (± SD) were 37.6 (± 7.7) years for HIV+ and 36.6 (± 7.9) years for HIV- women (p-value = 0.34). Among the HIV+ women, HPV35 (8.7%) and HPV56 (7.4%) were the most prevalent hrHPV, while HPV52 and HPV68 (2.8%, each) were the most prevalent hrHPV types among HIV- women. The multivariate prevalence ratio for any hrHPV and multiple hrHPV infections were 4.18 (95% CI 2.05 - 8.49, p-value <0.0001) and 6.6 (95% CI 1.49 - 29.64, p-value 0.01) respectively, comparing HIV + to HIV- women, adjusted for age, and educational level. CONCLUSIONS: HIV infection was associated with increased risk of any HPV, hrHPV and multiple HPV infections. Oncogenic HPV types 35, 52, 56 and 68 may be more important risk factors for cervical pre-cancer and cancer among women in Africa. Polyvalent hrHPV vaccines meant for African populations should protect against other hrHPV types, in addition to 16 and 18.

RPS19 and TYMS SNPs and Prevalent High Risk Human Papilloma Virus Infection in Nigerian Women.

High risk HPV (hrHPV) infection is a necessary cause of cervical cancer but the host genetic determinants of infection are poorly understood. We enrolled 267 women who presented to our cervical cancer screening program in Abuja, Nigeria between April 2012 and August 2012. We collected information on demographic characteristics, risk factors of cervical cancer and obtained samples of blood and cervical exfoliated cells from all participants. We used Roche Linear Array HPV Genotyping Test® to characterize the prevalent HPV according to manufacturer's instruction; Sequenom Mass Array to test 21 SNPs in genes/regions previously associated with hrHPV and regression models to examine independent factors associated with HPV infection. We considered a p<0.05 as significant because this is a replication study. There were 65 women with and 202 women without hrHPV infection. Under the allelic model, we found significant association between two SNPs, rs2305809 on RPS19 and rs2342700 on TYMS, and prevalent hrHPV infection. Multivariate analysis of hrHPV risk adjusted for age, body mass index, smoking, age of menarche, age at sexual debut, lifetime total number of sexual partners and the total number of pregnancies as covariates, yielded a p-value of 0.071 and 0.010 for rs2305809 and rs2342700, respectively. Our findings in this unique population suggest that a number of genetic risk variants for hrHPV are shared with other population groups. Definitive studies with larger sample sizes and using genome wide approaches are needed to understand the genetic architecture of hrHPV risk in multiple populations.

Pattern of dietary carbohydrate intake among urbanized adult Nigerians.

As the nutrition transition continues in Africa, it is crucial to identify population-specific dietary patterns. Healthy diets may then be promoted for prevention and alleviation of the chronic disease burden associated with nutrition. Using a semi-quantitate food frequency questionnaire, we conducted a cross-sectional study and computed the proportions of foods commonly consumed, and collected data on anthropometric characteristics. The median total energy intake per day from these carbohydrate sources was 1034 kcal (interquartile range (IOR) 621.5-1738.6 kcal). The main carbohydrate food eaten was rice (48.6%) followed by fufu (30.5%) and bread (13.1%). The prevalence of overweight and obesity was 63%, and 73% of the women in the study were either overweight or obese compared to 56% of men. Our study showed that parboiled long grain white rice is now the most commonly consumed carbohydrate by urbanized Nigerians. Other traditional carbohydrate foods are still consumed frequently and remain quite popular.

Challenges in treating malignancies in HIV in Nigeria.

PURPOSE OF REVIEW: Sub-Saharan Africa has the largest population of people living with AIDS in the world, with Nigeria having the third largest after South Africa and India. With the advent of treatment programs, more people in Nigeria are now living with the virus but are at increased risk of cancer similar to the experience in other parts of the world. This review uses publications on HIV-associated cancers emanating from Nigeria in 2008 to map the current landscape of prevention, diagnosis and treatment of these conditions. The opportunities and challenges identified in this review will provide a template for designing appropriate clinical and public health intervention to stem another epidemic, this time of AIDS-associated malignancies. RECENT FINDINGS: There is a paucity of literature on AIDS-associated cancers from Nigeria, and most reports are based on hospital or pathology case series. Poor case identification and diagnosis and rudimentary cancer registration militate against adequate quantification of the prevalence of AIDS-associated cancers in Nigeria. Several initiatives, working with the HIV treatment programs, governmental and nongovernmental local and international agencies, are rising to the challenge and creating new opportunities for cancer prevention, treatment and research that takes advantage of improved treatment infrastructure provided for people living with HIV/AIDS. SUMMARY: Nigeria is about to witness substantial increase in the background incidence of cancers due to high prevalence of HIV and expanded treatment programs. Creative methods are needed to deploy effective prevention, case identification, registration and treatment programs that are consistent with the socioeconomic development of the country.