51 research outputs found
Clinical Performance Validation of 4 Point-of-Care Cervical Cancer Screening Tests in HIV-Infected Women in Zambia
We sought to determine the clinical performance of visual inspection with acetic acid (VIA), digital cervicography (DC), Xpert HPV, and OncoE6 for cervical cancer screening in an HIV-infected population
Burden of respiratory tract infections at post mortem in Zambian children
Background: Autopsy studies are the gold standard for determining cause-of-death and can inform on improved diagnostic strategies and algorithms to improve patient care. We conducted a cross-sectional observational autopsy study to describe the burden of respiratory tract infections in inpatient children who died at the University Teaching Hospital in Lusaka, Zambia. Methods: Gross pathology was recorded and lung tissue was analysed by histopathology and molecular diagnostics. Recruitment bias was estimated by comparing recruited and non-recruited cases. Results: Of 121 children autopsied, 64 % were male, median age was 19 months (IQR, 12-45 months). HIV status was available for 97 children, of whom 34 % were HIV infected. Lung pathology was observed in 92 % of cases. Bacterial bronchopneumonia was the most common pathology (50 %) undiagnosed ante-mortem in 69 % of cases. Other pathologies included interstitial pneumonitis (17 %), tuberculosis (TB; 8 %), cytomegalovirus pneumonia (7 %) and pneumocystis Jirovecii pneumonia (5 %). Comorbidity between lung pathology and other communicable and non-communicable diseases was observed in 80 % of cases. Lung tissue from 70 % of TB cases was positive for Mycobacterium tuberculosis by molecular diagnostic tests. A total of 80 % of TB cases were comorbid with malnutrition and only 10 % of TB cases were on anti-TB therapy when they died. Conclusions: More proactive testing for bacterial pneumonia and TB in paediatric inpatient settings is needed
Observed and Expected Incidence of Cervical Cancer in Lusaka and the Southern and Western Provinces of Zambia, 2007 - 2012
Objectives—Cervical cancer is increasing but underestimated in developing countries. We calculated the observed and expected incidence of cervical cancer in Lusaka and Southern and Western provinces of Zambia.
Methods/Materials—Data for 2007-2012 was obtained for the 3 provinces. Data included age, residence, year of diagnosis, marital status, occupation, HIV, stage, radiotherapy and chemotherapy. Expected incidence in Southern and Western provinces was calculated based on observed incidence for Lusaka province, adjusting for HIV.
Results—Crude and age-standardized incidence rates (ASR) in Lusaka were 2-4 times higher than incidence in the other 2 provinces. Lusaka had a rate of 54.1/105 and ASR of 82.1/105 in the age group 15-49. The Southern province had a rate of 17.1/105 and ASR of 25.5/105; Western province rate of 12.3/105 and ASR rate of 17.2/105. The observed cervical cancer incidence rates in the Southern and Western provinces were lower than the rate in Lusaka, possibly due to the uncertainty of underreporting/under-diagnosis or actual lower risk for reasons yet unclear. HIV seroprevalence rate in patients from the 3 provinces were 46 – 93% higher than seroprevalence in the respective general populations.
Conclusion—Cervical cancer is significantly underestimated in Zambia and HIV has a significant role in pathogenesis. Future studies should establish methods for case ascertainment and better utilization of hospital- and population-based registries in Zambia and other similar developing countries
Identification of human papillomaviruses from formalin-fixed, paraffin-embedded pre-cancer and invasive cervical cancer specimens in Zambia: a cross-sectional study
BackgroundThe most common human papillomavirus (HPV) genotypes isolated from cervical cancer in select African countries are HPV-16, HPV-18, HPV-35, and HPV-45, but the most common genotypes in Zambia are unknown. The overall objective of this study was to assess the potential impact of current HPV vaccines in preventing cervical cancer in Zambia, by determining the combined prevalence of HPV-16 and/or HPV-18 in invasive cervical cancer (ICC) and high-grade pre-cancer [cervical intraepithelial neoplasia 2 or 3 (CIN2/3)] cases.FindingsWe compared DNA extraction techniques to determine which assay performs well in the Zambian context, where unbuffered formalin is used to fix specimens. We then tested specimens with the Abbott RealTime High-Risk HPV test to estimate the prevalence of HPV-16/18 in formalin-fixed, paraffin-embedded ICC and CIN2/3 specimens. DNA extraction using heat (without xylene) was more successful than xylene-based extraction. Over 80% of specimens tested using heat extraction and the Abbott RealTime HPV test were positive for HPV. HPV-16 and/or HPV-18 were identified in 65/93 (69.9%) ICC specimens positive for HPV and in 38/65 (58.5%) CIN2/3 specimens positive for HPV.ConclusionsTo our knowledge this is the first report to identify HPV genotypes in cervical cancers in Zambia. A combined HPV-16/18 prevalence of 69.9% in ICC specimens suggests that current vaccines will be highly protective against cervical cancer in Zambia
Drivers of advanced stage at breast cancer diagnosis in the multicountry African breast cancer - disparities in outcomes (ABC-DO) study.
Breast cancer (BC) survival rates in sub-Saharan Africa (SSA) are low in part due to advanced stage at diagnosis. As one component of a study of the entire journey of SSA women with BC, we aimed to identify shared and setting-specific drivers of advanced stage BC. Women newly diagnosed in the multicountry African Breast Cancer-Disparities in Outcomes (ABC-DO) study completed a baseline interview and their stage information was extracted from medical records. Ordinal logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for advanced stage (I, II, III, IV) in relation to individual woman-level, referral and biological factors. A total of 1795 women were included from Nigeria, Uganda, Zambia, and the multiracial populations of Namibia and South Africa, 1091 of whom (61%) were stage III/IV. Stage was lower in women with greater BC knowledge (OR 0.77 (95% CI: 0.70, 0.85) per point on a 6 point scale). More advanced stage was associated with being black (4.00 (2.79, 5.74)), having attended <secondary education (1.75 (1.42, 2.16)), having never heard of BC (1.64 (1.31, 2.06)), an unskilled job (1.77 (1.43, 2.20)) and pregnancy in the past 3 years (30% of ≤45 year olds) (1.63 (1.15, 2.31)), and were mediated through delays to diagnosis: symptom duration of ≥ 1 year (OR 2.47 (1.93, 3.15)). These findings provide further evidence that late-stage BC in SSA is largely attributed to modifiable factors and strategies to improve BC education and awareness in women and the health system should be intensified
Clinical Performance of Digital Cervicography and Cytology for Cervical Cancer Screening in HIV-Infected Women in Lusaka, Zambia
While there is a growing literature on the clinical performance of VIA in HIV-infected women, to our knowledge none have studied VIA enhanced by digital cervicography. We estimated clinical performance of cervicography and cytology to detect cervical intraepithelial neoplasia grade 2 or worse. Sensitivity and specificity of cervicography were 84% (95% confidence interval [CI]: 72%–91%) and 58% (95%CI: 52%–64%). At the high-grade squamous intraepithelial lesion or worse cutoff for cytology, sensitivity and specificity were 61% (95%CI: 48%–72%) and 58% (95%CI: 52%–64%). In our study, cervicography appears to be as good as cytology in HIV-infected women
Incidental Tuberculosis in sudden, unexpected, or violent deaths in the community Lusaka, Zambia - A descriptive forensic post-mortem examination study
Objectives: Tuberculosis remains a global emergency. In Zambia only 55% of tuberculosis cases are diagnosed. We performed a study to determine incidental cases of tuberculosis seen at forensic autopsy of individuals who died suddenly and unexpectedly in the community in Lusaka, Zambia.
Methods: Whole-body autopsies were performed according to Standard Operating Procedures. Representative samples obtained from relevant organs were subjected to pathological examination. Information on circumstances surrounding the death was obtained. Data on patient demographics, gross and microscopic pathological findings, and cause(s) of death were analysed.
Results: Incidental tuberculosis was found in 52 cases (45 male, 7 female, age range 14-66) out of 4286 whole-body autopsies. 41/52 (80%) were aged 21-50 years. One was a 14-year old boy who died during a football match. 39/52 (75%) deaths were attributable specifically to tuberculosis only. Other deaths were due to acute alcohol intoxication(4), violence(7), ruptured ectopic pregnancy(1), bacterial meningitis (1). All the cases were from poor socio-economic backgrounds and lived in high-density areas of Lusaka.
Conclusions: Incidental cases of active tuberculosis undiagnosed antemortem seen at forensic autopsy reflects major gaps in the national TB control programs. More investments into proactive screening, testing, treatment activities, and accurate data collection are required
Three transmission events of Vibrio cholerae O1 into Lusaka, Zambia
Cholera has been present and recurring in Zambia since 1977. However, there is a paucity of data on genetic relatedness and diversity of the Vibrio cholerae isolates responsible for these outbreaks. Understanding whether the outbreaks are seeded from existing local isolates or if the outbreaks represent separate transmission events can inform public health decisions. Seventy-two V. cholerae isolates from outbreaks in 2009/2010, 2016, and 2017/2018 in Zambia were characterized using multilocus variable number tandem repeat analysis (MLVA) and whole genome sequencing (WGS). The isolates had eight distinct MLVA genotypes that clustered into three MLVA clonal complexes (CCs). Each CC contained isolates from only one outbreak. The results from WGS revealed both clustered and dispersed single nucleotide variants. The genetic relatedness of isolates based on WGS was consistent with the MLVA, each CC was a distinct genetic lineage and had nearest neighbors from other East African countries. In Lusaka, isolates from the same outbreak were more closely related to themselves and isolates from other countries than to isolates from other outbreaks in other years. Our observations are consistent with i) the presence of random mutation and alternative mechanisms of nucleotide variation, and ii) three separate transmission events of V. cholerae into Lusaka, Zambia. We suggest that locally, case-area targeted invention strategies and regionally, well-coordinated plans be in place to effectively control future cholera outbreaks.https://doi.org/10.1186/s12879-021-06259-
Identification of human papillomaviruses from formalin-fixed, paraffin-embedded pre-cancer and invasive cervical cancer specimens in Zambia: a cross-sectional study
First COVID-19 case in Zambia — Comparative phylogenomic analyses of SARS-CoV-2 detected in African countries
Since its first discovery in December 2019 in Wuhan, China, COVID-19, caused by the novel coronavirus SARS-CoV-2, has spread rapidly worldwide. While African countries were relatively spared initially, the initial low incidence of COVID-19 cases was not sustained for long due to continuing travel links between China, Europe and Africa. In preparation, Zambia had applied a multisectoral national epidemic disease surveillance and response system resulting in the identification of the first case within 48 h of the individual entering the country by air travel from a trip to France. Contact tracing showed that SARS-CoV-2 infection was contained within the patient’s household, with no further spread to attending health care workers or community members. Phylogenomic analysis of the patient’s SARS-CoV-2 strain showed that it belonged to lineage B.1.1., sharing the last common ancestor with SARS-CoV-2 strains recovered from South Africa. At the African continental level, our analysis showed that B.1 and B.1.1 lineages appear to be predominant in Africa. Whole genome sequence analysis should be part of all surveillance and case detection activities in order to monitor the origin and evolution of SARS-CoV-2 lineages across Africa
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