Pausing the Fight Against Malaria to Combat the COVID-19 Pandemic in Africa: Is the Future of Malaria Bleak?

Malaria remains a major global health burden, killing hundreds of thousands annually, especially in sub-Saharan Africa. In 2019, a Phase IV Expanded Programme on Immunization (EPI)-linked malaria vaccine implementation was underway. However, in December 2019, a novel pneumonia condition termed coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with many clinical, epidemiological, and biological parallels to malaria, was reported in Wuhan, China. COVID-19 is spreading rapidly, and, as of the 3rd of June, 2020, more than 382,507 persons had died from COVID-19. Children under 5 years who suffer high malaria-attributable mortalities are largely asymptomatic for COVID-19. Considering that the malaria burden is highest in low-income tropical countries with little capacity to fund malaria control and eradication programs, the fight against malaria in these regions is likely to be hampered. Access to healthcare has generally been limited, while malaria interventions, such as seasonal malaria chemotherapy and distribution of insecticide-treated bed nets, have been suspended due to lockdowns. Likewise, the repurposing of antimalarials for treatment of COVID-19 shared symptoms and the shift in focus from the production of malaria rapid diagnostic tests (RDTs) to COVID-19 RDTs is a cause for concern in malaria-endemic regions. Children are less affected by the COVID-19 pandemic compared to the elderly. However, due to the fears of contracting SARS-CoV-2, the elderly who are worst affected by COVID-19 may not take children for malaria medication, resulting in high malaria-related mortalities among children. COVID-19 has disproportionately affected developed countries, threatening their donation capacity. These are likely to thwart malaria control efforts in low-income regions. Here, we present perspectives on the collateral impact of COVID-19 on malaria, especially in Africa

USPOREDNA PERFORMANSA RASTA MUŽJAKA ISTOG SPOLA I MJEŠOVITOG SPOLA NILSKE TILAPIJE (Oreochromis niloticus L.) UZGAJANIH U ZEMLJANIM RIBNJACIMA

Comparative growth performance of male monosex and mixed sex Nile tilapia (Oreochromis niloticus) was conducted in six earthen ponds each measuring 150 m2 at the Kenya Marine & Fisheries Research Institute (KMFRI), Kegati Aquaculture Research Station. Male monosex and mixed sex of O. niloticus juveniles at an average weight of 12.2 ± 0.02 g and average length of 7.6 ± 0.02 cm were collected from nursery production ponds. The male monosex juveniles were obtained by feeding newly hatched juveniles with feed dosed with 17-α-methyltestosterone hormone for a period of one month. Stocking was at 3 juvenile m-2 and feeding was carried out using 28% crude protein diet twice daily for six months at 4% body weight. Selected water quality parameters (dissolved oxygen, temperature, pH, electrical conductivity and total ammonia nitrogen) were measured weekly in situ, while sampling for weight and length measurements was conducted on a monthly basis for a period of six months. Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Condition Factor (CF) and survival rate (%) were measured at the end of six months. Data were subjected to one-way analysis of variance (ANOVA). At the end of six months, the average weight of male monosex and mixed sex fishes was 200.8 ± 0.81 g (mean ± SE) and 123.4 ± 0.76 g, respectively, while the average length of male monosex and mixed sex was 22.4 ± 0.21 cm and 18.6 ± 0.23 cm, respectively. The male monosex O. niloticus achieved significantly increased final weight and length, SGR, FCR and CF than the mixed sex O. niloticus (p 0.05). There were no significant differences in mean water quality parameters in male monosex and mixed sex ponds (p > 0.05). The male monosex fish performed better because most energy was spent on muscle and tissue development while the mixed sex fish spent most energy on reproduction activities at the expense of muscle and tissue development. Further studies should be done in other culture systems such as liner ponds, tanks, cages and raceways.Usporedna performansa rasta mužjaka istog spola u odnosu na mješoviti spol Nilske tilapije (Oreochromis niloticus) provedena je u šest zemljanih ribnjaka veličine 150 m2 u Kenijskom institutu za istraživanje mora i ribarstva (KMFRI), Akvakulturna stanica u Kegatiju. Nedozrele jedinke mužjaka istog spola i mješovitog spola O. niloticus prosječne mase 12,2 ± 0,02 g i prosječne dužine 7,6 ± 0,02 cm prikupljene su iz mladičnjaka. Nedozrele jedinke mužjaka su dobivene hranjenjem novoizleglih ličinaka s hranom doziranom hormonom 17 α-metil-testosteronom u razdoblju od mjesec dana. Nasad je proveden u gustoći od 3 mladunca / m2 i hranidbom od 28% sirovih proteina dva puta dnevno tijekom šest mjeseci na 4% tjelesne težine. Odabrani fizikalno-kemijski parametri vode (otopljen kisik, temperatura, provodljivost i ukupni amonijak) mjereni su tjedno in situ, dok su izmjere dužina i masa provedene na mjesečnoj bazi tijekom 6 mjeseci. Specifična stopa rasta (SGR), omjer konverzije hrane (FCR), kondicijski faktor (CF) i stopa preživljavanja (%) izmjereni su na kraju perioda od šest mjeseci. Podaci su analizirani jednosmjernom analizom varijance (ANOVA). Na kraju promatranog perioda od 6 mjeseci, prosječna težina mužjaka istog spola iznosila je 200,8 ± 0,81 g (prosjek ± standardna devijacija) i mješovitog spola 123,4 ± 0,76 g, a prosječna dužina mužjaka istog spola iznosila je 22,4 ± 0,21 cm i mješovitog spola 18,6 ± 0,23 cm. Mužjaci istog spola O. niloticus postigli su značajno veću konačnu težinu i dužinu, SGR, FCR i CF nego mješoviti spol (p 0,05). Nije zabilježena značajna razlika u kvaliteti mjerenih parametara u vodi ribnjaka promatranih skupina riba (p > 0,05). Mužjaci istog spola imaju bolje rezultate jer je većina energije potrošena na mišiće i razvoj tkiva, dok je mješoviti spol trošio najviše energije na reprodukcijske aktivnosti na račun mišića i razvoj tkiva. Daljnja istraživanja bi trebala biti usmjerena ka drugim sustavima uzgoja poput obloženih ribnjaka, zatvorenih bazena, kaveza i protočnih kanala

Distribution of Anopheles gambiae thioester-containing protein 1 alleles along malaria transmission gradients in The Gambia.

BACKGROUND: Thioester-containing protein 1 (TEP1) is a highly polymorphic gene playing an important role in mosquito immunity to parasite development and associated with Anopheles gambiae vectorial competence. Allelic variations in TEP1 could render mosquito either susceptible or resistant to parasite infection. Despite reports of TEP1 genetic variations in An. gambiae, the correlation between TEP1 allelic variants and transmission patterns in malaria endemic settings remains unclear. METHODS: TEP1 allelic variants were characterized by PCR from archived genomic DNA of > 1000 An. gambiae mosquitoes collected at 3 time points between 2009 and 2019 from eastern Gambia, where malaria transmission remains moderately high, and western regions with low transmission. RESULTS: Eight common TEP1 allelic variants were identified at varying frequencies in An. gambiae from both transmission settings. These comprised the wild type TEP1, homozygous susceptible genotype, TEP1s; homozygous resistance genotypes: TEP1rA and TEP1rB, and the heterozygous resistance genotypes: TEP1srA, TEP1srB, TEP1rArB and TEP1srArB. There was no significant disproportionate distribution of the TEP1 alleles by transmission setting and the temporal distribution of alleles was also consistent across the transmission settings. TEP1s was the most common in all vector species in both settings (allele frequencies: East = 21.4-68.4%. West = 23.5-67.2%). In Anopheles arabiensis, the frequency of wild type TEP1 and susceptible TEP1s was significantly higher in low transmission setting than in high transmission setting (TEP1: Z = - 4.831, P < 0.0001; TEP1s: Z = - 2.073, P = 0.038). CONCLUSIONS: The distribution of TEP1 allele variants does not distinctly correlate with malaria endemicity pattern in The Gambia. Further studies are needed to understand the link between genetic variations in vector population and transmission pattern in the study settings. Future studies on the implication for targeting TEP1 gene for vector control strategy such as gene drive systems in this settings is also recommended

Comprehensive transcriptome of the maize stalk borer, Busseola fusca, from multiple tissue types, developmental stages, and parasitoid wasp exposures

International audienc

Molecular and bio-analytical characterisation as a means to understand genetic diversity within Kenyan Aspergillus flavus strains

Toxigenic Aspergillus species produce mycotoxins that are carcinogenic, hepatotoxic and teratogenic immunosuppressing agents in both human and animals. Kenya frequently experiences outbreaks of aflatoxicosis with the worst occurring in 2004, which resulted in 125 deaths. This study sought to find possible reasons for frequent aflatoxicosis outbreaks in Kenya by isolating Aspergillus flavus strains from maize kernels sampled from different climatic regions of Kenya. Using diagonal transect random sampling, maize kernels were collected from Makueni, Homa Bay, Nandi, and Kisumu regions. The genetic diversity and variation among the isolates was examined by characterising the strains according to morphology, phenotype, vegetative compatible groups and molecular systematics. Selected atoxigenic and aflatoxigenic A. flavus isolates were also further analysed for aflatoxin production potential using quantitative real-time PCR and various bioanalytical techniques. The influence of the maize lines grown in Kisumu, Homa Bay, Nandi and Makueni region on A. flavus infection and aflatoxin production was also examined and served as the basis for an in vitro biocontrol assay. Out of 37 isolates identified, nitrate non-utilizing auxotroph’s complementation test revealed 20 vegetative compatibility groups. These groups were further designated using the prefix ʻʻKVCGʼʼ, where ʻʻKʼʼ represented Kenya and consequently assigned numbers 1 to 20 based on our findings. KVCG14 and KVCG15 had highest distribution frequency (n = 13; 10.8 %). The distribution of the L, S and S/L- morphotypes across the regions were 57 % (n = 21); 7 % (n = 3) and 36 % (n = 13) respectively. The phylogenetic analysis exhibited high diversity of A. flavus isolates from Makueni. ITS1 and ITS2 markers did not reveal significant information within intraspecies speciation of A. flavus. Furthermore, a unique isolate (KSM015) was identified that had characteristics of S-morphotype, but produced both aflatoxins B and G. Coconut agar medium (CAM) assay, TLC, HPLC and LCMS/MS analyses confirmed the presence or absence of aflatoxins in selected toxigenic and atoxigenic isolates. qPCR analysis revealed aflP, aflS, aflR and aflO transcripts as the most upregulated genes across the tested isolates whereas false detection of aflD gene transcript was observed in both induced and uninduced A. flavus isolates. Diversity Index (H) analyses ranged from 0.11 (Nandi samples) to 0.32 (Kisumu samples). Heterokaryon compatibility ranged from 33 % (for the Makueni samples, n = 3) to 67 % (Nandi samples, n = 6). The KDV1 maize line was more sensitive to A. flavus infection in comparison to GAF4. We also tested the biocontrol of atoxigenic isolates to inhibit toxin production by aflatoxigenic strains on infected maize kernels. It was shown that the atoxigenic strain (KSMO12) could inhibit the aflatoxigenic strain (KSM014) depending on the atoxigenic concentration during infection. To our knowledge, this is the first reported study for A. flavus genetic diversity, variation and distribution in Nandi, Homa Bay and Kisumu regions in comparison to and could assist researchers in the selection of biocontrol strategies to mitigate aflatoxin contamination, especially in Makueni and neighbouring regions

Implementation and Operational Research

BackgroundAcademic Model Providing Access To Healthcare (AMPATH) program provides comprehensive HIV care and treatment services. Approximately, 30% of patients have become lost to follow-up (LTFU). We sought to actively trace and identify outcomes for a sample of these patients.MethodsLTFU was defined as missing a scheduled visit by ≥3 months. A randomly selected sample of 17% of patients identified as LTFU between January 2009 and June 2011 was generated, with sample stratification on age, antiretroviral therapy (ART) status at last visit, and facility. Chart reviews were conducted followed by active tracing. Tracing was completed by trained HIV-positive outreach workers July 2011 to February 2012. Outcomes were compared between adults and children and by ART status.ResultsOf 14,811 LTFU patients, 2540 were randomly selected for tracing (2179 adults, 1071 on ART). The chart reviews indicated that 326 (12.8%) patients were not actually LTFU. Outcomes for 71% of sampled patients were determined including 85% of those physically traced. Of those with known outcomes, 21% had died, whereas 29% had disengaged from care for various reasons. The remaining patients had moved away (n = 458, 25%) or were still receiving HIV care (n = 443 total, 25%).ConclusionsOur findings demonstrate the feasibility of a large-scale sampling-based approach. A significant proportion of patients were found not to be LTFU, and further, high numbers of patients who were LTFU could not be located. Over a quarter of patients disengaged from care for various reasons including access challenges and familial influences

Effect of climatic variability on malaria trends in Baringo County, Kenya

Abstract Background Malaria transmission in arid and semi-arid regions of Kenya such as Baringo County, is seasonal and often influenced by climatic factors. Unravelling the relationship between climate variables and malaria transmission dynamics is therefore instrumental in developing effective malaria control strategies. The main aim of this study was to describe the effects of variability of rainfall, maximum temperature and vegetation indices on seasonal trends of malaria in selected health facilities within Baringo County, Kenya. Methods Climate variables sourced from the International Research Institute (IRI)/Lamont-Doherty Earth Observatory (LDEO) climate database and malaria cases reported in 10 health facilities spread across four ecological zones (riverine, lowland, mid-altitude and highland) between 2004 and 2014 were subjected to a time series analysis. A negative binomial regression model with lagged climate variables was used to model long-term monthly malaria cases. The seasonal Mann–Kendall trend test was then used to detect overall monotonic trends in malaria cases. Results Malaria cases increased significantly in the highland and midland zones over the study period. Changes in malaria prevalence corresponded to variations in rainfall and maximum temperature. Rainfall at a time lag of 2 months resulted in an increase in malaria transmission across the four zones while an increase in temperature at time lags of 0 and 1 month resulted in an increase in malaria cases in the riverine and highland zones, respectively. Conclusion Given the existence of a time lag between climatic variables more so rainfall and peak malaria transmission, appropriate control measures can be initiated at the onset of short and after long rains seasons

Ecological niche modelling of Rift Valley fever virus vectors in Baringo, Kenya.

BackgroundRift Valley fever (RVF) is a vector-borne zoonotic disease that has an impact on human health and animal productivity. Here, we explore the use of vector presence modelling to predict the distribution of RVF vector species under climate change scenario to demonstrate the potential for geographic spread of Rift Valley fever virus (RVFV).ObjectivesTo evaluate the effect of climate change on RVF vector distribution in Baringo County, Kenya, with an aim of developing a risk map for spatial prediction of RVF outbreaks.MethodologyThe study used data on vector presence and ecological niche modelling (MaxEnt) algorithm to predict the effect of climatic change on habitat suitability and the spatial distribution of RVF vectors in Baringo County. Data on species occurrence were obtained from longitudinal sampling of adult mosquitoes and larvae in the study area. We used present (2000) and future (2050) Bioclim climate databases to model the vector distribution.ResultsModel results predicted potential suitable areas with high success rates for Culex quinquefasciatus, Culex univitattus, Mansonia africana, and Mansonia uniformis. Under the present climatic conditions, the lowlands were found to be highly suitable for all the species. Future climatic conditions indicate an increase in the spatial distribution of Cx. quinquefasciatus and M. africana. Model performance was statistically significant.ConclusionSoil types, precipitation in the driest quarter, precipitation seasonality, and isothermality showed the highest predictive potential for the four species

High seroprevalence of Immunoglobulin G (IgG) and IgM antibodies to SARS-CoV-2 in asymptomatic and symptomatic individuals amidst vaccination roll-out in western Kenya.

The population's antibody response is a key factor in comprehending SARS-CoV-2 epidemiology. This is especially important in African settings where COVID-19 impact, and vaccination rates are relatively low. This study aimed at characterizing the Immunoglobulin G (IgG) and Immunoglobulin M (IgM) in both SARS-CoV-2 asymptomatic and symptomatic individuals in Kisumu and Siaya counties in western Kenya using enzyme linked immunosorbent assays. The IgG and IgM overall seroprevalence in 98 symptomatic and asymptomatic individuals in western Kenya between December 2021-March 2022 was 76.5% (95% CI = 66.9-84.5) and 29.6% (95% CI = 20.8-39.7) respectively. In terms of gender, males had slightly higher IgG positivity 87.5% (35/40) than females 68.9% (40/58). Amidst the ongoing vaccination roll-out during the study period, over half of the study participants (55.1%, 95% CI = 44.7-65.2) had not received any vaccine. About one third, (31.6%, 95% CI = 22.6-41.8) of the study participants had been fully vaccinated, with close to a quarter (13.3% 95% CI = 7.26-21.6) partially vaccinated. When considering the vaccination status and seroprevalence, out of the 31 fully vaccinated individuals, IgG seropositivity was 81.1% (95% CI = 70.2-96.3) and IgM seropositivity was 35.5% (95% CI = 19.22-54.6). Out of the participants that had not been vaccinated at all, IgG seroprevalence was 70.4% (95% CI 56.4-82.0) with 20.4% (95% CI 10.6-33.5) seropositivity for IgM antibodies. On PCR testing, 33.7% were positive, with 66.3% negative. The 32 positive individuals included 12(37.5%) fully vaccinated, 8(25%) partially vaccinated and 12(37.5%) unvaccinated. SARs-CoV-2 PCR positivity did not significantly predict IgG (p = 0.469 [95% CI 0.514-4.230]) and IgM (p = 0.964 [95% CI 0.380-2.516]) positivity. These data indicate a high seroprevalence of antibodies to SARS-CoV-2 in western Kenya. This suggests that a larger fraction of the population was infected with SARS-CoV-2 within the defined period than what PCR testing could cover