Gastric adenocarcinoma in Zambia: A case-control study of HIV, lifestyle risk factors, and biomarkers of pathogenesis

Background. Gastric cancer is a leading cause of cancer deaths worldwide but there are few data from Africa. We recently observed a trendtowards diagnosis in younger patients.Objective. To test the hypothesis that HIV might have altered risk factors for acquisition of gastric cancer, in a case-control study in theUniversity Teaching Hospital, Lusaka, Zambia.Methods. Patients (n=52) with confirmed gastric adenocarcinoma and controls (n=94) undergoing endoscopy but with no macroscopicgastric pathology. Established risk factors and HIV status were compared.Results. HIV status did not differ significantly between cases and controls (odds ratio 1.03; 95% CI 0.2 - 4.3; p=1.00) and seroprevalencein cases was similar to that of the Zambian population. Smoking, regular alcohol intake, and gastric atrophy were all associated with cancerin univariate and multivariate analysis. Helicobacter pylori serology was positive in 84% of patients studied and cytotoxin-associated gene A(cagA) serology in 66%; neither serological marker was associated with cancer. Atrophy was common in cases (57%) and controls (30%) andassociated with both smoking and alcohol use. Intestinal metaplasia was present in 17% of the controls, but was not associated with atrophy.Conclusions. HIV was not associated with gastric cancer and does not explain the apparent younger age distribution. Atrophy was commonand was not essential for the development of intestinal metaplasia, suggesting that gastric carcinogenesis in Africa does not always followthe pathway from atrophy to intestinal metaplasia to gastric carcinoma (the so-called Correa pathway)

Clinical and ultrasonographic features of abdominal tuberculosis in HIV positive adults in Zambia

Background: The diagnosis of abdominal tuberculosis (TB) is difficult, especially so in health care facilities in developing countries where laparoscopy and colonoscopy are rarely available. There is little information on abdominal TB in HIV infection. We estimated the prevalence and clinical features of abdominal (excluding genitourinary) TB in HIV infected adults attending the University Teaching Hospital, Zambia. Methods: We screened 5,609 medical inpatients, and those with fever, weight loss, and clinical features suggestive of abdominal pathology were evaluated further. A clinical algorithm was used to specify definitive investigations including laparoscopy or colonoscopy, with culture of biopsies and other samples. Results: Of 140 HIV seropositive patients with these features, 31 patients underwent full evaluation and 22 (71%) had definite or probable abdominal TB. The commonest presenting abdominal features were ascites and persistent tenderness. The commonest ultrasound findings were ascites, para-aortic lymphadenopathy (over 1 cm in size), and hepatomegaly. Abdominal TB was associated with CD4 cell counts over a wide range though 76% had CD4 counts <100 cells/μL. Conclusion: The clinical manifestations of abdominal TB in our HIV-infected patients resembled the well-established pattern in HIV-uninfected adults. Patients with fever, weight loss, abdominal tenderness, abdominal lymphadenopathy, ascites and/or hepatomegaly in Zambia have a high probability of abdominal TB, irrespective of CD4 cell count. © 2009 Sinkala et al; licensee BioMed Central Ltd

Gastric Malignancy Survival in Zambia, Southern Africa: A two year follow up study

Background: Gastric cancer poses a significant global health burden. It is the second most common cause of cancer death worldwide and the ninth leading cause of cancer mortality in Zambia, at a rate of 3.8/100,000; comparable to USA (2/100,000) and UK (3.4/100,000). Survival data on gastric malignancy in Zambia is not known.Objectives: To provide preliminary survival rates of patients with histologically proven gastric adenocarcinoma in Zambia.Study Design: Using our prospective gastric cancer research database, we conducted a retrospective audit of patients diagnosed with gastric cancer at the University Teaching Hospital, Zambia, from June 2010 until January 2012. We contacted patients or their relatives using phone numbers provided at time of enrollment.Main Outcomes: We reviewed age, sex, demographic data (income, education), body mass index, symptoms, duration of symptoms, treatment (surgery, chemotherapy, radiotherapy or combination) and survival outcome.  Analysis was performed using Kaplan-Meier models and log rank test.Results: Fifty one patients were diagnosed with gastric adenocarcinoma during the study period, but follow-up data were available for 50. Median survival was 142 days. Age, sex, income, education, BMI, tumor location, and treatment modality were not significantly associated with overall survival. In Cox regression models, covariates associated with survival were a history of regular alcohol intake (HR 0.49, 95%CI 0.26,0.92; P=0.025) and intestinal type cancer histology (HR 0.40, 95%CI 0.19,0.83; P=0.01).Conclusion: Prognosis of newly diagnosed gastric cancer in Zambia is poor with significant mortality within 1 yearof diagnosis, particularly among patients with weight loss and dysphagia

A Three-Dimensional Constitutive Model for Rocks Based on a Strain-Dependent Elastic Modulus

AbstractOur research group previously proposed a simple two-dimensional (2D) constitutive model for rocks to simulate not only the axial stress–axial strain relationship, but also the axial stress–lateral strain relationship, with few complicated equations. However, the failure envelope that it predicted was linear, and it did not consider the effect of the intermediate principal stress (σ2). In the present study, the authors modify this simple 2D model to have a convex failure criterion. Then, the model is extended to a simple three-dimensional (3D) model that well approximates true triaxial stress–strain curves for real rocks under specific values of σ2 and σ3 and uses only four parameters. However, the predicted peak stress–σ2 relationship is linear. Finally, a modified 3D model was developed, which exhibited the true triaxial convex failure criterion. The equations in this model are simpler than the conventional true triaxial failure criteria. The proposed models can be implemented with a finite element method to improve the design of rock structures

High Uptake of Exclusive Breastfeeding and Reduced Early Post-Natal HIV Transmission

BACKGROUND. Empirical data showing the clear benefits of exclusive breastfeeding (EBF) for HIV prevention are needed to encourage implementation of lactation support programs for HIV-infected women in low resource settings among whom replacement feeding is unsafe. We conducted a prospective, observational study in Lusaka, Zambia, to test the hypothesis that EBF is associated with a lower risk of postnatal HIV transmission than non-EBF. METHODS AND RESULTS. As part of a randomized trial of early weaning, 958 HIV-infected women and their infants were recruited and all were encouraged to breastfeed exclusively to 4 months. Single-dose nevirapine was provided to prevent transmission. Regular samples were collected from infants to 24 months of age and tested by PCR. Detailed measurements of actual feeding behaviors were collected to examine, in an observational analysis, associations between feeding practices and postnatal HIV transmission. Uptake of EBF was high with 84% of women reporting only EBF cumulatively to 4 months. Post-natal HIV transmission before 4 months was significantly lower (p = 0.004) among EBF (0.040 95% CI: 0.024–0.055) than non-EBF infants (0.102 95% CI: 0.047–0.157); time-dependent Relative Hazard (RH) of transmission due to non-EBF = 3.48 (95% CI: 1.71–7.08). There were no significant differences in the severity of disease between EBF and non-EBF mothers and the association remained significant (RH = 2.68 95% CI: 1.28–5.62) after adjusting for maternal CD4 count, plasma viral load, syphilis screening results and low birth weight. CONCLUSIONS. Non-EBF more than doubles the risk of early postnatal HIV transmission. Programs to support EBF should be expanded universally in low resource settings. EBF is an affordable, feasible, acceptable, safe and sustainable practice that also reduces HIV transmission providing HIV-infected women with a means to protect their children's lives. TRIAL REGISTRATION. ClinicalTrials.gov NCT00310726National Institute of Child Health and Human Development; National Institutes of Health (R01 HD 39611, R01 HD 40777); Centers for Disease Control and Prevention; Global AIDS Program; Glaser Pediatric AIDS Foundation; USAID Country Research (GHS-A-00-00020-00

Characterization of foot-and-mouth disease viruses in Zambia-implications for the epidemiology of the disease in southern Africa

The livestock industry supports livelihood and nutritional security of at least 42% of people in the Southern African Development Community region. However, presence of animal diseases such as foot-and-mouth disease poses a major threat to the development of this industry. Samples collected from FMD outbreaks in Zambia during 2015–2020, comprising epithelial tissues samples (n = 47) and sera (n = 120), were analysed. FMD virus was serotyped in 26 samples, while 92 sera samples tested positive on NSP-ELISA. Phylogenetic analysis revealed notable changes in the epidemiology of FMD in Zambia, which included: (i) introduction of a novel FMDV SAT-3 (topotype II) causing FMD cases in cattle in Western Province; (ii) emergence of FMDV serotype O (topotype O/EA-2) in Central, Southern, Copperbelt, Western, Lusaka Provinces; and (iii) new outbreaks due to SAT -2 (topotypes I) in Eastern Zambia. Together, these data describe eight different epizootics that occurred in Zambia, four of which were outside the known FMD high-risk areas. This study highlights the complex epidemiology of FMD in Zambia, where the country represents an interface between East Africa (Pool 4) and Southern Africa (Pool 6). These changing viral dynamics have direct impacts on FMD vaccine selection in the SADC region.The Government of Zambia through the Ministry of Fisheries and Livestock, Department of Veterinary; the UK Department of the Environment, Food and Rural Affairs (Defra SE2944) and the European Union.http://www.mdpi.com/journal/virusespm2022Veterinary Tropical Disease

Chronic hepatitis B virus monoinfection at a university hospital in Zambia.

AIM: To characterize antiviral therapy eligibility among hepatitis B virus (HBV)-infected adults at a university hospital in Zambia. METHODS: Hepatitis B surface antigen-positive adults (n = 160) who were HIV-negative and referred to the hospital after a routine or clinically-driven HBV test were enrolled. Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), platelet count, hepatitis B e-antigen, and HBV DNA were measured. Liver fibrosis/cirrhosis was assessed by physical examination, AST-to-platelet ratio index, and transient elastography. In antiviral therapy-naïve individuals, we described HBV stages and antiviral therapy eligibility per World Health Organization (WHO) and by HBV test (routine vs clinical). Elevated ALT was > 19 in women and > 30 U/L in men. Among treatment-experienced individuals, we described medication side effects, adherence, and viral suppression. RESULTS: The median age was 33 years, 71.9% were men, and 30.9% were diagnosed with HBV through a clinically-driven test with the remainder identified via routine testing (at the blood bank, community events, etc.). Among 120 treatment-naïve individuals, 2.5% were categorized as immune tolerant, 11.7% were immune active, 35.6% were inactive carriers, and 46.7% had an indeterminate phenotype. Per WHO guidelines, 13 (10.8%) were eligible for immediate antiviral therapy. The odds of eligibility were eight times higher for those diagnosed at clinical vs routine settings (adjusted odds ratio, 8.33; 95%CI: 2.26-29.41). Among 40 treatment-experienced HBV patients, virtually all took tenofovir, and a history of mild side effects was reported in 20%. Though reported adherence was good, 12 of 29 (41.4%) had HBV DNA > 20 IU/mL. CONCLUSION: Approximately one in ten HBV-monoinfected Zambians were eligible for antivirals. Many had indeterminate phenotype and needed clinical follow-up.School of Medicine at University of Alabama at Birmingham; Fogarty International Center, No. K01TW009998; National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, No. U01AI069924; and Swiss National Science Foundation (to Wandeler G), No. PZ0093_154730

Practices of traditional beef farmers in their production and marketing of cattle in Zambia

Understanding the practices of traditional cattle farmers in developing countries is an important factor in the development of appropriate, pro-poor disease control policies, and in formulating regional-specific production incentives that can improve productivity. This paper describes the production, husbandry practices, economics, and constraints of traditional cattle farming in Zambia. A cross-sectional study design was used to obtain data from traditional cattle farmers (n = 699) using a structured questionnaire. Data analyses were carried out using SPSS and STATA statistical packages. The results revealed that the majority [65% (95% CI: 59.3–71.1)] of farmers practised a transhumant cattle herding system under communal grazing. In these transhumant herding systems, animal husbandry and management systems were found to be of poor quality, in terms of supplementary feeding, vaccination coverage, deworming, uptake of veterinary services, usage of artificial insemination, and dip tanks all being low or absent. East Coast Fever was the most common disease, affecting 60% (95% CI: 56.4–63.7) of farmers. Cattle sales were low, as farmers only sold a median of two cattle per household per year. Crop farming was found to be the main source of farm income (47%) in agro-pastoralist communities, followed by cattle farming (28%) and other sources (25%). The median cost of production in the surveyed provinces was reported at US$316, while that of revenue from cattle and cattle products sales was estimated at US$885 per herd per year. This translates to an estimated gross margin of US$569, representing 64.3% of revenue. There is considerable diversity in disease distribution, animal husbandry practices, economics, and challenges in traditional cattle production in different locations of Zambia. Therefore, to improve the productivity of the traditional cattle sub-sector, policy makers and stakeholders in the beef value chain must develop fit-for-purpose policies and interventions that consider these variations

Trends in upper gastrointestinal diagnosis over four decades in Lusaka, Zambia: a retrospective analysis of endoscopic findings

BACKGROUND AND AIMS: There a shortage of robust information about profiles of gastrointestinal disease in sub-Saharan Africa. The endoscopy unit of the University Teaching Hospital in Lusaka has been running without interruption since 1977 and this 38-year record is largely intact. We report an analysis of endoscopic findings over this period. METHODS: Written endoscopy records from 29th September 1977 to 16th December 2014 were recovered, computerised, coded by two experienced endoscopists and analysed. Temporal trends were analysed using tables, graphs, and unconditional logistic regression, with age, sex of patient, decade, and endoscopist as independent variables to adjust for inter-observer variation. RESULTS: Sixteen thousand nine hundred fifty-three records were identified and analysed. Diagnosis of gastric ulcer rose by 22 %, and that of duodenal ulcer fell by 14 % per decade. Endoscopically diagnosed oesophageal cancer increased by 32 % per decade, but gastric cancer rose only in patients under 60 years of age (21 % per decade). Oesophageal varices were the commonest finding in patients presenting with haematemesis, increasing by 14 % per decade in that patient group. Two HIV-related diagnoses, oesophageal candidiasis and Kaposi’s sarcoma, rose from almost zero to very high levels in the 1990s but fell substantially after 2005 when anti-retroviral therapy became widely available. CONCLUSIONS: This useful dataset suggests that there are important trends in some endoscopic findings over four decades. These trends are not explained by inter-observer variation. Reasons for the divergent trends in incidence of peptic ulceration and apparent trends in diagnosis of upper gastrointestinal cancers merit further exploration