Growth and Mortality of Mouth Brooding Tilapiines of the Kafue Floodplain Fishery, Zambia

Growth and mortality of Oreochromis andersonii, Oreochromis macrochir and Oreochromis niloticusof the Kafue Floodplain fishery were investigated between September, 2015 and November, 2015. This study was aimed at investigating the growth and mortality of mouth brooding tilapiines of the Kafue Floodplain fishery. Three stations that represent the major ecological habitats of the Kafue Floodplain fishery were selected. These were: Kafue Road Bridge (swamp), Namalyo (lagoon) and Kakuzu (riverine). Fish specimens were collected using gillnets that were set in the evening and hauled the next morning. Length measurements were taken from each fish specimen using a fish measuring board. Weight was measured using a kitchen balance to the nearest one gramme. One-way Analysis of Variance was performed on all quantitative data using Statistix 9.0 software. Oreochromis niloticus showed the largest growth coefficient (k) of 0.22 while Oreochromis macrochir had the smallest growth coefficient of 0.10.  Oreochromis andersonii had a growth coefficient of 0.11. Exploitation ratios in the Kafue Floodplain fishery were found to be below the optimum value (0.5) except for Oreochromis macrochir (0.7). Oreochromis andersonii had an exploitation ratio of 0.3 while Oreochromis niloticus had an exploitation ratio of 0.4. This implies that the decrease in fish catches in the Kafue Floodplain fishery cannot be attributed to over-fishing but may be due to natural mortality

How do farmers and seed producers get information and provide feedback on varieties in the public domain: the case of common bean in eastern Zambia?

A Study conducted by the Zambia Agriculture Research Institute (ZARI) and Seed Control and Certification Institute (SCCI) with the International Center for Tropical Agriculture (CIAT)A study was conducted in 2015 to investigate the channels used by farmers and seed producers to access information on bean varieties in the Eastern Province of Zambia, particularly in Chadiza, Chipata, Lundazi and Vubwi districts. Stakeholders, key informants and a sample of 300 bean-producing households were interviewed. Two focus group discussions (FGDs) were also conducted in Chadzombe and Chiwoko Agricultural Camps to contextualize the survey responses. The 300 households produced beans under rain-fed and irrigated wetland conditions, and also grew maize (87 %) and other legumes such as groundnut (66 %) and soybean (61%). Concerning bean production, the majority of respondents (88%) grew only local varieties while 6 % grew only improved varieties, 6% grew both varieties and the remainder (less than 1 %) were unware whether their varieties of choice were local or improved

HIV-1 Effects on Neuropsychological Performance in a Resource-Limited Country, Zambia

Zambia has substantially been affected by the HIV/AIDS epidemic with prevalence rates at 14% in a population estimated at 12 million. Yet, the extent of HIV-associated neurocognitive disorders (HAND) in this population remains to be clearly understood. A series of culturally appropriate neuropsychological (NP) assessments [International HIV Dementia Scale (IHDS), Color Trails Test 1 and 2, Grooved pegboard Test, and Time Gait Test] were used to test the effects of HIV on NP performance of HIV seropositive and seronegative individuals. Twenty-two percent HIV positive individuals ARV naïve met the criteria for IHDS-defined NP impairment. Gender significantly influenced the performance on NP tests with females performing more poorly compared to males. Larger studies that will accommodate gender differences and age are necessary to generate appropriate norms in Zambia in order to better assess the prevalence of HAND in the developing country setting

Evidence for Histidine-Rich Protein 2 Immune Complex Formation in Symptomatic Patients in Southern Zambia

Background: Rapid diagnostic tests based on histidine-rich protein 2 (HRP2) detection are the primary tools used to detect Plasmodium falciparum malaria infections. Recent conflicting reports call into question whether α-HRP2 antibodies are present in human host circulation and if resulting immune complexes could interfere with HRP2 detection on malaria RDTs. This study sought to determine the prevalence of immune-complexed HRP2 in a low-transmission region of Southern Zambia. Methods: An ELISA was used to quantify HRP2 in patient sample DBS extracts before and after heat-based immune complex dissociation. A pull-down assay reliant on proteins A, G, and L was developed and applied for IgG and IgM capture and subsequent immunoprecipitation of any HRP2 present in immune complexed form. A total of 104 patient samples were evaluated using both methods. Results: Immune-complexed HRP2 was detectable in 17% (18/104) of all samples evaluated and 70% (16/23) of HRP2-positive samples. A majority of the patients with samples containing immune-complexed HRP2 had P. falciparum infections (11/18) and were also positive for free HRP2 (16/18). For 72% (13/18) of patients with immune-complexed HRP2, less than 10% of the total HRP2 present was in immune-complexed form. For the remaining samples, a large proportion (≥ 20%) of total HRP2 was complexed with α-HRP2 antibodies. Conclusions: Endogenous α-HRP2 antibodies form immune complexes with HRP2 in the symptomatic patient population of a low-transmission area in rural Southern Zambia. For the majority of patients, the percentage of HRP2 in immune complexes is low and does not affect HRP2-based malaria diagnosis. However, for some patients, a significant portion of the total HRP2 was in immune-complexed form. Future studies investigating the prevalence and proportion of immune-complexed HRP2 in asymptomatic individuals with low HRP2 levels will be required to assess whether α-HRP2 antibodies affect HRP2 detection for this portion of the transmission reservoir

Plasmodium Falciparum HRP2 Elisa for Analysis of Dried Blood Spot Samples in Rural Zambia

Background: Dried blood spots are commonly used for sample collection in clinical and non-clinical settings. This method is simple, and biomolecules in the samples remain stable for months at room temperature. In the field, blood samples for the study and diagnosis of malaria are often collected on dried blood spot cards, so development of a biomarker extraction and analysis method is needed. Methods: A simple extraction procedure for the malarial biomarker Plasmodium falciparum histidine-rich protein 2 (HRP2) from dried blood spots was optimized to achieve maximum extraction efficiency. This method was used to assess the stability of HRP2 in dried blood spots. Furthermore, 328 patient samples made available from rural Zambia were analysed for HRP2 using the developed method. These samples were collected at the initial administration of artemisinin-based combination therapy and at several points following treatment. Results: An average extraction efficiency of 70% HRP2 with a low picomolar detection limit was achieved. In specific storage conditions HRP2 was found to be stable in dried blood spots for at least 6 months. Analysis of patient samples showed the method to have a sensitivity of 94% and a specificity of 89% when compared with microscopy, and trends in HRP2 clearance after treatment were observed. Conclusions: The dried blood spot ELISA for HRP2 was found to be sensitive, specific and accurate. The method was effectively used to assess biomarker clearance characteristics in patient samples, which prove it to be ideal for gaining further insight into the disease and epidemiological applications

Evaluating the impact of programmatic mass drug administration for malaria in Zambia using routine incidence data.

BACKGROUND NlmCategory: BACKGROUND content: In 2016, the Zambian National Malaria Elimination Centre started programmatic mass drug administration (pMDA) campaigns with dihydroartemisinin-piperaquine as a malaria elimination tool in Southern Province. Two rounds were administered, two months apart (coverage 70% and 57% respectively). We evaluated the impact of one year of pMDA on malaria incidence using routine data. - Label: METHODS NlmCategory: METHODS content: We conducted an interrupted time series with comparison group analysis on monthly incidence data collected at the health facility catchment area (HFCA) level, with a negative binomial model using generalized estimating equations. pMDA was conducted in HFCAs with greater than 50 cases/1,000 people/year. Ten HFCAs with incidence rates marginally above this threshold (pMDA group) were compared to 20 HFCAs marginally below (comparison group). - Label: RESULTS NlmCategory: RESULTS content: "The pMDA HFCAs saw a 46% greater decrease in incidence at the time of intervention than the comparison areas (incidence rate ratio: 0.536 [0.337-0.852]); however, incidence increased toward the end of the season. No HFCAs saw a transmission interruption." - Label: CONCLUSION NlmCategory: CONCLUSIONS content: pMDA, implemented during one year with imperfect coverage in low transmission areas with sub-optimal vector control coverage, significantly reduced incidence. However, elimination will require additional tools. Routine data are important resources for programmatic impact evaluations and should be considered for future analyses

Surveillance of molecular markers for antimalarial resistance in Zambia: Polymorphism of Pfkelch 13, Pfmdr1 and Pfdhfr/Pfdhps genes

Antimalarial resistance is an inevitable feature of control efforts and a key threat to achieving malaria elimination. Plasmodium falciparum, the deadliest of several species causing human malaria, has developed resistance to essentially all antimalarials. This study sought to investigate the prevalence of molecular markers associated with resistance to sulfadoxine-pyrimethamine (SP) and artemether-lumefantrine (AL) in Southern and Western provinces in Zambia. SP is used primarily for intermittent preventive treatment during pregnancy, while AL is the first-line antimalarial for uncomplicated malaria in Zambia. Blood samples were collected from household members of all ages in a cross-sectional survey conducted during peak malaria transmission, April to May of 2017, and amplified by polymerase chain reaction (PCR). Amplicons were then analysed by high-resolution melt following PCR to identify mutations associated with SP resistance in the P. falciparum dihydrofolate reductase (Pfdhfr) and P. falciparum dihydropteroate synthase (Pfdhps) genes and lumefantrine resistance in the P. falciparum multi-drug resistance 1 (Pfmdr1) gene. Finally, artemether resistance was assessed in the P. falciparum Kelch 13 (PfK13) gene using nested PCR followed by amplicon sequencing. The results showed a high frequency of genotypic-resistant Pfdhps A437G (93.2%) and Pfdhfr C59R (86.7%), N51I (80.9%), and S108N (80.8%) of which a high proportion (82.4%) were quadruple mutants (Pfdhfr N51I, C59R, S108N +Pfdhps A437G). Pfmrd1 N86Y, Y186F, and D1246Y - NFD mutant haplotypes were observed in 41.9% of isolates. The high prevalence of quadruple dhps/dhfr mutants indicates strong antifolate drug pressure from SP or other drugs (e.g., co-trimoxazole). Three samples contained PfK13 mutations, two synonymous (T478 and V666) and one non-synonymous (A578S), none of which have been associated with delayed clearance. This suggests that artemisinin remains efficacious in Zambia, however, the moderately high prevalence of approximately 40% Pfmdr1 NFD mutations calls for close monitoring of AL.publishedVersio

Controlled Release Spatial Repellent Devices (CRDS) as Novel Tools Against Malaria Transmission: A Semi-Field Study in Macha, Zambia

Background: The emergence of mosquitoes that can avoid indoor-deployed interventions, such as treated bed nets and indoor residual spraying, threatens the mainstay of malaria control in Zambia. Furthermore, the requirement for high coverage of these tools poses operational challenges. Spatial repellents are being assessed to supplement these vector control tools, but limitations exist in the residual effect of the repellent and the need for external power or heat for diffusion of the volatiles. Methods: A semi-field evaluation of a novel controlled release spatial repellent device (CRD) was conducted in Macha, Zambia. These devices emanate metofluthrin with no need for external power. Devices were deployed in huts within the semi-field system (SFS). Female Anopheles gambiae sensu stricto released within the SFS were trapped overnight by light traps and collected by aspiration the next morning inside and outside of huts to determine the extent of mosquito repellency and the impact on host-seeking and survival. Experiments studied the impact of number of devices as well as the presence of hut occupants. The study was complemented with numerical methods based on computational fluid dynamics to simulate spatial distribution of metofluthrin. Results: Presence of CRDs was associated with significant reductions in indoor counts of mosquitoes, regardless of whether huts were occupied or not. Repellency ranged from 15 to 60% compared to huts with no devices. Reducing the number of devices from 16 to 4 had little impact on repellency. When huts were occupied, indoor mosquito host-seeking was higher in the presence of CRDs, whilst survival was significantly reduced. Conclusions: This study demonstrated that deployment of as few as four CRDs within a hut was associated with reduced indoor mosquito densities. As would be expected, presence of occupants within huts, resulted in greater indoor catches (both with and without devices). The increased indoor mosquito host-seeking and mortality in huts when devices were present may be explained by the excito-repellency activity of metofluthrin. These semi-field experiments provide preliminary data on the utility of CRD spatial repellents to reduce indoor densities of An. gambiae mosquitoes. Studies will further investigate the impact of CRDs on mosquito behaviour as well as epidemiological protective efficacy

Factors influencing COVID-19 health protective behaviours in Zambian university students with symptoms of low mood

BackgroundHealth protective behaviours are crucial in the prevention of the spread of COVID-19, particularly in university students who typically live and study in large groups. Depression and anxiety are common in students and can impact young people’s motivations to follow health advice. The study aims to assess the relationship between mental health and COVID-19 health-protective behaviours in Zambian university students with symptoms of low mood.MethodsThe study was a cross-sectional, online survey of Zambian university students. Participants were also invited to take part in a semi-structured interview to explore views about COVID-19 vaccination. Invitation emails were sent explaining the study aims and directed students who self-identified as having low mood in the past two weeks to an online survey. Measures included COVID-19 preventive behaviours, COVID-19-related self-efficacy, and Hospital and Anxiety Depression scale.ResultsA total of 620 students (n=308 female, n=306 male) participated in the study, with a mean participant age of 22.47±3.29 years (range 18–51). Students reported a mean protective behaviour score of 74.09/105 and 74% scored above the threshold for possible anxiety disorder. Three-way ANOVA showed lower COVID-19 protective behaviours in students with possible anxiety disorder (p=.024) and those with low self-efficacy (p<0.001). Only 168 (27%) said they would accept vaccination against COVID-19, with male students being twice as likely to be willing to accept COVID-19 vaccination (p<0.001). Of 50 students interviewed. 30 (60%) expressed fears about the vaccination and 16 (32%) were concerned about a lack of information. Only 8 (16%) participants expressed doubts about effectiveness.ConclusionStudents who self-identify as having symptoms of depression have high levels of anxiety. The results suggest that interventions to reduce anxiety and promote self-efficacy might enhance students’ COVID-19 protective behaviours. Qualitative data provided insight into the high rates of vaccine hesitancy in this population

Implementing internet-based cognitive behavioural therapy (moodgym) for African students with symptoms of low mood during the COVID-19 pandemic: a qualitative feasibilty study

Background: Online therapies have been shown to be effective in improving students’ mental health. They are cost-effective and therefore have particular advantages in low-income countries like Zambia where mental health resources are limited. This study aimed to explore the perceived impact of the COVID-19 pandemic and the feasibility of implementing an Internet-Based Cognitive Behavioural Therapy (iCBT) intervention (‘moodgym’) to improve resilience in vulnerable Zambian students. Methods: The study was a qualitative interview study. Participants identifying as having symptoms of low mood and completing a baseline, online survey (n = 620) had the option to volunteer for a semi-structured interview to explore views about their experience of the pandemic and the acceptability and perceived benefits and limitations of using moodgym. Results: A total of 50 students (n = 24 female, n = 26 male) participated in the study. One theme with 4 sub-themes, captured the severe emotional and social impact of the COVID-19 pandemic. A second, very strong theme, with 5 sub-themes, reflected the considerable negative effects of the pandemic on the students’ educational experience. This included the challenges of online learning. The third theme, with three subthemes, captured the benefits and acceptability of moodgym, particularly in terms of understanding the relationship between thoughts and feelings and improving academic performance. The fourth theme described the technical difficulties experienced by students in attempting to use moodgym. Conclusion: COVID-19 caused fear and impacted wellbeing in vulnerable students and severely impaired the quality of students’ educational experience. The findings suggest that moodgym might be a valuable support to students in a low-income country