Burnout and use of HIV services among health care workers in Lusaka District, Zambia: a cross-sectional study

Background  

Well-documented shortages of health care workers in sub-Saharan Africa are exacerbated by the increased human resource demands of rapidly expanding HIV care and treatment programmes. The successful continuation of existing programmes is threatened by health care worker burnout and HIV-related illness.     

Spatial analysis of risk factor of cholera outbreak for 2003-2004 in a peri-urban area of Lusaka, Zambia

A cholera outbreak occurred in Lusaka city between November 28, 2003 and June 8, 2004, and 6,542 cases with 187 deaths (case fatality rata: 2.86) were reported. We analyzed the distribution of cholera cases, the mode of cholera transmission, and the risk factors affecting cholera infection in a peri-urban area of Lusaka by using a Geographic Information System (GIS) and a matched case-control method. Chloropleth mapping of the incidences of cholera showed variation of the incidences in the study area. Our analysis indicated a significant association between the lack of latrine and drainage systems surrounding houses and high incidence of cholera. The matched case-control study showed the protective role of chlorination of drinking water and of hand washing with soap for cholera prevention. We concluded that cholera occurred because of personal behavior and the environment conditions of daily life.     

Genomic Signature of Multidrug-Resistant Salmonella enterica Serovar Typhi Isolates Related to a Massive Outbreak in Zambia between 2010 and 2012

Retrospectively, we investigated the epidemiology of a massive Salmonella enterica serovar Typhi outbreak in Zambia during 2010 to 2012. Ninety-four isolates were susceptibility tested by MIC determinations. Whole-genome sequence typing (WGST) of 33 isolates and bioinformatic analysis identified the multilocus sequence type (MLST), haplotype, plasmid replicon, antimicrobial resistance genes, and genetic relatedness by single nucleotide polymorphism (SNP) analysis and genomic deletions. The outbreak affected 2,040 patients, with a fatality rate of 0.5%. Most (83.0%) isolates were multidrug resistant (MDR). The isolates belonged to MLST ST1 and a new variant of the haplotype, H58B. Most isolates contained a chromosomally translocated region containing seven antimicrobial resistance genes, catA1, bla_TEM-1, dfrA7, sul1, sul2, strA, and strB, and fragments of the incompatibility group Q1 (IncQ1) plasmid replicon, the class 1 integron, and the mer operon. The genomic analysis revealed 415 SNP differences overall and 35 deletions among 33 of the isolates subjected to whole-genome sequencing. In comparison with other genomes of H58, the Zambian isolates separated from genomes from Central Africa and India by 34 and 52 SNPs, respectively. The phylogenetic analysis indicates that 32 of the 33 isolates sequenced belonged to a tight clonal group distinct from other H58 genomes included in the study. The small numbers of SNPs identified within this group are consistent with the short-term transmission that can be expected over a period of 2 years. The phylogenetic analysis and deletions suggest that a single MDR clone was responsible for the outbreak, during which occasional other S. Typhi lineages, including sensitive ones, continued to cocirculate. The common view is that the emerging global S. Typhi haplotype, H58B, containing the MDR IncHI1 plasmid is responsible for the majority of typhoid infections in Asia and sub-Saharan Africa; we found that a new variant of the haplotype harboring a chromosomally translocated region containing the MDR islands of IncHI1 plasmid has emerged in Zambia. This could change the perception of the term “classical MDR typhoid” currently being solely associated with the IncHI1 plasmid. It might be more common than presently thought that S. Typhi haplotype H58B harbors the IncHI1 plasmid or a chromosomally translocated MDR region or both.     

The impact of an immunization programme administered through the Growth Monitoring Programme Plus as an alternative way of implementing Integrated Management of Childhood Illnesses in urban-slum areas of Lusaka, Zambia

A time-lag study design was used to examine the effects of an immunization programme implemented through an integrated community-based child health approach called the Growth Monitoring Programme Plus (GMP+) in peri-urban areas of Lusaka, Zambia. The immunization coverage and sociodemographic data of eligible children and households were obtained from three repeated surveys in two intervention areas. Logistic regression analysis was performed to explore the factors affecting immunization coverage. For assessing the timeliness of immunization, a Computerised Immunization Coverage Calculation System (CICCS) was used. Full immunization coverage significantly increased in both the primary intervention (P < 0.001) and lagged intervention (P = 0.011) areas after the initiation of the GMP+. Frequent attendance to GMP+ sessions played a significant role in the improvement of immunization coverage (P < 0.001 for the final survey in the primary intervention area), whereas other sociodemographic characteristics of the child and caretaker were not associated with immunization coverage. Analysis of the timeliness of three doses of diphtheria, pertussis and tetanus DPT3 immunization by CICCS showed that coverage in the primary intervention area had significantly improved compared to the lagged intervention area. Our study indicated that immunization coverage was improved effectively with the intervention of the GMP+ as a model of an integrated immunization programme for child health in line with the Integrated Management of Childhood Illnesses (IMCI) and the Global Immunization Vision and Strategy (GIVS).     

Interaction of lidocaine and benzocaine in depressing Vmax of ventricular action potentials

This paper reports the interactions between lidocaine and benzocaine with cardiac sodium channels. The magnitude of the maximum upstroke velocity (Vmax) of the guinea-pig papillary muscle action potential was taken as an indirect measurement of the sodium current. The hypothesis that both the charged and neutral forms of local anaesthetics share a common receptor was tested. In preparations stimulated at a frequency of 0.1 Hz, a mixture of equieffective concentrations of benzocaine and lidocaine produced a decrease in Vmax similar to that obtained with each of the drugs alone. Therefore, the tonic blockade produced with this mixture of anaesthetics was comparable with the theoretical values predicted by equilibrium binding equations, which is indicative of a common receptor for both drugs. Although benzocaine did not produce frequency-dependent effects, it did attenuate those produced by lidocaine when both anaesthetics were applied. During repeated action potentials, using short diastolic intervals, the frequency-dependent effects of lidocaine were due to the accumulation of blocked sodium channels. The binding of lidocaine to both open and inactivated channels during a conditioning action potential was determined by the zero-time intercept of the slow component of the recovery of Vmax induced by the drug. Under these conditions, benzocaine decreased the fraction of channels blocked by lidocaine. Hence, the parallel shift produced by benzocaine on the dose-response (fraction of blocked Vmax) curves of lidocaine, strongly suggests that both drugs competed for the same receptor site. Furthermore, this receptor, mediating the blockade of cardiac sodium channels, seems to be responsible for both the tonic and frequency-dependent effect of lidocaine on the heart.     

Simple adherence assessments to predict virologic failure among HIV-infected adults with discordant immunologic and clinical responses to antiretroviral therapy

We evaluated the association between two antiretroviral therapy (ART) adherence measurements--the medication possession ratio (MPR) and patient self-report--and detectable HIV viremia in the setting of rapid service scale-up in Lusaka, Zambia. Drug adherence and outcomes were assessed in a subset of patients suspected of treatment failure based on discordant clinical and immunologic responses to ART. A total of 913 patients were included in this analysis, with a median time of 744 days (Q1, Q3: 511, 919 days) from ART initiation to viral load (VL) measurement. On aggregate over the period of follow-up, 531 (58%) had optimal adherence (MPR > or =95%), 306 (34%) had suboptimal adherence (MPR 80-94%), and 76 (8%) had poor adherence (MPR <80%). Of the 913 patients, 238 (26%) had VL > or =400 copies/ml when tested. When compared to individuals with optimal adherence, there was increasing risk for virologic failure in those with suboptimal adherence [adjusted relative risk (ARR): 1.3; 95% confidence interval (CI): 1.0, 1.6] and those with poor adherence (ARR: 1.7; 95% CI: 1.3, 2.4) based on MPR. During the antiretroviral treatment course, 676 patients (74%) reported no missed doses. The proportion of patients with virologic failure did not differ significantly among those reporting any missed dose from those reporting perfect adherence (26% vs. 26%, p = 0.97). Among patients with suspected treatment failure, a lower MPR was associated with higher rates of detectable viremia. However, the suboptimal sensitivity and specificity of MPR limit its utility as a sole predictor of virologic failure.     

Interrupted time-series analysis of active case-finding for tuberculosis during the COVID-19 pandemic,Zambia

ObjectiveTo evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic and the subsequent implementation of tuberculosis response measures on tuberculosis notifications in Zambia.MethodsWe used an interrupted time-series design to compare monthly tuberculosis notifications in Zambia before the pandemic (January 2019 to February 2020), after implementation of national pandemic mitigation measures (April 2020 to June 2020) and after response measures to improve tuberculosis detection (August 2020 to September 2021). The tuberculosis response included enhanced data surveillance, facility-based active case-finding and activities to generate demand for services. We used nationally aggregated, facility-level tuberculosis notification data for the analysis.FindingsPre-pandemic tuberculosis case notifications rose steadily from 2890 in January 2019 to 3337 in February 2020. After the start of the pandemic and mitigation measures, there was a −22% (95% confidence interval, CI: −24 to −19) immediate decline in notifications in April 2020. Larger immediate declines in notifications were seen among human immunodeficiency virus (HIV)-positive compared with HIV-negative individuals (−36%; 95% CI: −38 to −35; versus −12%; 95% CI: −17 to −6). Following roll-out of tuberculosis response measures in July 2020, notifications immediately increased by 45% (95% CI: 38 to 51) nationally and across all subgroups and provinces. The trend in notifications remained stable through September 2021, with similar numbers to the predicted number had the pandemic not occurred.ConclusionImplementation of a coordinated public health response including active tuberculosis case-finding was associated with reversal of the adverse impact of the pandemic and mitigation measures. The gains were sustained throughout subsequent waves of the pandemic.