Sickle cell disease and pulmonary hypertension in Africa: a global perspective and review of epidemiology, pathophysiology, and management

Secondary pulmonary hypertension (PAH) has been shown to have a prevalence of 30% in patients with sickle cell disease (SCD) with mortality rates of 40% at 40 months after diagnosis in the United States. The burden of SCD is highest in sub-Saharan Africa, especially in Nigeria (West Africa), where approximately 6 million people are afflicted. The true global incidence, prevalence, and burden of SCD and its associated end organ complications however remain unknown. Chronic hemolysis represents a prominent mechanistic pathway in the pathogenesis of SCD-associated pulmonary hypertension via a nitric oxide (NO) scavenging and abrogation of NO salutatory effects on vascular function, including smooth muscle relaxation, downregulation of endothelial adhesion molecules and inhibition of platelet activation. Many known infectious risk factors for PAH are also hyperendemic in Africa, including Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS), chronic hepatitis B and C, and possibly malaria. Interactions between these infectious complications and SCD-related hemolysis could yield an even higher prevalence of pulmonary hypertension and compound the existing global health systems challenges in managing SCD. Indeed, our preliminary analysis of African immigrants currently in the United States suggests that pulmonary hypertension represents a significant complication of SCD in the African subcontinent. There is clearly a need to include Africa and other parts of the world with high SCD prevalence in future comprehensive studies on the epidemiology and treatment of end organ complications of an aging SCD population world-wide.     

Hepatitis B and C in doctors and dentists in Nigeria

We surveyed a random sample (n = 75) of doctors and dentists at University College Hospital, Ibadan, Nigeria. They were offered anonymous testing for hepatitis B surface antigen (HBsAg), hepatitis Be antigen (HBeAG), antibodies to hepatitis B core antigen (anti-HBc) and to hepatitis C virus (anti-HCV), by enzyme immunoassay. The results suggest a high prevalence of hepatitis B virus (HBV) with a high potential of transmissibility, as well as a high prevalence of HCV infection. The majority of the doctors and dentists use universal precaution for protection against viral hepatitis on < 50% of the occasions when they carry out procedures on their patients. Infection with HBV was associated with type of specialty (surgeons, dentists) and lack of HBV vaccination (p < 0.05). After logistic regression, these factors were independently associated with HBV infection (p < 0.05). Sixty (80%) had not received prior HBV vaccination. Unvaccinated personnel were more likely to be surgeons, dentists, < 37 years of age, and have fewer years of professional activity (p < 0.05). After logistic regression, only fewer years of professional activity remained independently associated with lack of vaccination (p < 0.05). To reduce the occupational exposure of HBV, universal precautions must be rigorously adhered to when the doctors and dentists carry out procedures on their patients, and all health-care workers should be vaccinated with HBV vaccine and the HCV vaccine, when it becomes available.      

The role of management on costs and efficiency in HIV prevention interventions for female sex workers in Nigeria: a cluster-randomized control trial

Background

While the world has made much global progress toward the reduction of new HIV infections, HIV continues to be an important public health problem. In the face of constantly constrained resources, donors and grantees alike must seek to optimize resources and deliver HIV services as efficiently as possible. While there is evidence that management practices can affect efficiency, this has yet to be rigorously tested in the context of HIV service delivery.

Methods

The present protocol describes the design of a cluster-randomized control trial to estimate the effect of management practices on efficiency. Specifically, we will evaluate the impact of an intervention focused on improving management practices among community-based organizations (CBOs), on the costs of HIV prevention services for female sex workers (FSW) in Nigeria. To design the intervention, we used a qualitative, design thinking-informed methodology that allowed us to understand management in its organizational context better and to develop a user-centered solution. After designing the suite of management tools, we randomly assigned 16 CBOs to the intervention group, and 15 CBOs to the control group. The intervention consisted of a comprehensive management training and a management “toolkit” to support better planning and organization of their work and better communication between CBOs and community volunteers. Both treatment and control groups received training to record data on efficiency—inputs used, and outputs produced. Both groups will be prospectively followed through to the end of the study, at which point we will compare the average unit cost per FSW served between the two groups using a quasi-experimental “difference-in-differences” (DiD) strategy. This approach identifies the effect of the intervention by examining differences between treatment and control groups, before and after the intervention thus accounting for time-constant differences between groups. Despite the rigorous randomization procedure, the small sample size and diversity in the country may still cause unobservable characteristics linked to efficiency to unbalanced between treatment and control groups at baseline. In anticipation of this possibility, using the quasi-experimental DiD approach allows any baseline differences to be “differenced out” when measuring the effect.

Discussion

This study design will uniquely add to the literature around management practices by building rigorous evidence on the relationship between management skills and practices and service delivery efficiency. We expect that management will positively affect efficiency. This study will produce valuable evidence that we will disseminate to key stakeholders, including those integral to the Nigerian HIV response.Trial registration This trial has been registered in Clinical Trials (NCT03371914). Registered 13 December 2018

     

Changes in prepregnancy body mass index between pregnancies and risk of gestational and type 2 diabetes

Introduction  

We investigated whether changes in interpregnancy body mass index (BMI) influence the risk of gestational and type 2 diabetes among a cohort of women with two consecutive live, singleton births of 20–44 weeks gestation (n = 232,272).     

Seroprevalence and determinants of human herpes virus 8 infection in adult Nigerians with and without HIV-1 infection

Background

There is a dearth of studies on HHV8-HIV co-infections from Nigeria, even as both infections have been shown to be endemic in Africa. This study examined the seroprevalence and determinants of HHV8 infections in adult Nigerians with and without HIV-infection.

Methods

In 2007, a cross sectional study undertaken in a tertiary hospital in Zaria, northern Nigeria enrolled 71 HIV-1 positive adults without Kaposi''s sarcoma and 85 apparently healthy HIV-negative adult volunteers of the general population. Anti-lytic antibodies to HHV8 infection was determined by ELISA. A univariate analysis including age, sex, marital status, past sexually transmitted disease (STD), past blood transfusion, HIV/AIDS staging and CD4 count was used to determine variables associated with HHV8 seropositivity. Significant variables were adjusted in a logistic regression model expressed in odds ratio (OR) with 95% confidence interval (CI). P<0.05 was considered significant

Results

The seroprevalence of HHV8 infection was 62% in HIV-1 positive patients and 25.9% in HIV negative adults (p<0.001). A past history of STD [OR= 2.88, 95% CI= 1.0 – 8.2] and advanced HIV/AIDS (WHO stage 3 and 4) [OR=3.5, 95% CI= 1.21–10.1] were the only variables independently associated with HHV8 seropositivity in HIV-infected patients. In HIV-negative adults, none of the variables was significantly associated with HHV8 seropositivity.

Conclusion

The study findings suggest an adverse interaction between HHV8 and HIV-1. The higher prevalence of HHV8 infection in HIV-infected patients and its association with STD support a predominant sexual route of HHV8 transmission among adult Nigerians.     

Alcohol Consumption During Pregnancy and Risk of Placental Abruption and Placenta Previa

The purpose of this study was to examine the association between prenatal alcohol consumption and the occurrence of placental abruption and placenta previa in a population-based sample. We used linked birth data files to conduct a retrospective cohort study of singleton deliveries in the state of Missouri during the period 1989 through 2005 (n = 1,221,310). The main outcomes of interest were placenta previa, placental abruption and a composite outcome defined as the occurrence of either or both lesions. Multivariate logistic regression was used to generate adjusted odd ratios, with non-drinking mothers as the referent category. Women who consumed alcohol during pregnancy had a 33% greater likelihood for placental abruption during pregnancy (adjusted odds ratio (OR), 95% confidence interval (CI) = 1.33 [1.16–1.54]). No association was observed between prenatal alcohol use and the risk of placenta previa. Alcohol consumption in pregnancy was positively related to the occurrence of either or both placental conditions (adjusted OR [95% CI] = 1.29 [1.14–1.45]). Mothers who consumed alcohol during pregnancy were at elevated risk of experiencing placental abruption, but not placenta previa. Our findings underscore the need for screening and behavioral counseling interventions to combat alcohol use by pregnant women and women of childbearing age.     

Parity effect on preterm birth and growth outcomes among infants with isolated omphalocele

OBJECTIVE: To assess the association between parity and fetal morbidity outcomes among omphalocele-affected fetuses. STUDY DESIGN: We carried out a retrospective study of 498 cases of isolated omphalocele (210 born to nulliparous and 288 to multiparous mothers) in New York State from 1983 through 1999. Infants of nulliparous mothers were compared to those of multiparous gravidas using adjusted odds ratios generated from a logistic regression. RESULTS: Omphalocele-affected fetuses of nulliparous mothers had a lower risk of being delivered preterm (odds ratio (OR)=0.49; 95% CI=0.27-0.90) but comparable risks for low birth weight (OR=1.01; 95% CI=0.60-1.72), very low birth weight (OR=0.33; 95% CI=0.09-1.20), very preterm birth (OR=0.42; 95% CI=0.15-1.16), and small size for gestational age (SGA) [OR=0.61; 95% CI=0.23-1.63]. CONCLUSION: Omphalocele-affected fetuses of multiparous mothers have double the risk for preterm birth compared to their nulliparous counterparts. This information is potentially useful in counseling parents whose fetuses have omphaloceles.