High Prevalence of Asymptomatic Malarial Anemia and Association with Early Conversion from Asymptomatic to Symptomatic Infection in a Plasmodium falciparum Hyperendemic Setting in Cameroon

2021 ◽  
Author(s):  
Balotin Fogang ◽  
Marie Fslorence Biabi ◽  
Rosette Megnekou ◽  
Franklin M. Maloba ◽  
Estelle Essangui ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Negative Impact ◽  
Female Gender ◽  
Asymptomatic Malaria ◽  
Nested Polymerase Chain Reaction ◽  
Symptomatic Infection ◽  
Malaria Parasitemia ◽  
High Prevalence ◽  
Prevalence Of Anemia ◽  
Malarial Anemia

Asymptomatic malarial parasitemia is highly prevalent in Plasmodium falciparum endemic areas and often associated with increased prevalence of mild to moderate anemia. The aim of this study was to assess the prevalence of anemia during asymptomatic malaria parasitemia and its interplay with persistent infection in highly exposed individuals. A household-based longitudinal survey was undertaken in a malaria hyperendemic area in Cameroon using multiplex nested polymerase chain reaction to detect plasmodial infections. Residents with P. falciparum asymptomatic parasitemia were monitored over a 3-week period with the aid of structured questionnaires and weekly measurements of axillary temperatures. Of the 353 individuals included (median age: 26 years, range 2–86 years, male/female sex ratio 0.9), 328 (92.9%) were positive for malaria parasitemia of whom 266 (81.1%) were asymptomatic carriers. The prevalence of anemia in the study population was 38.6%, of which 69.2% were asymptomatic. Multivariate analyses identified high parasitemia (> 327 parasites/µL) and female gender as associated risk factors of asymptomatic malarial anemia in the population. Furthermore, risk analyses revealed female gender and anemia at the time of enrolment as key predictors of early development of febrile illness (< 3 weeks post enrolment) among the asymptomatic individuals. Together, the data reveal an extremely high prevalence of asymptomatic malaria parasitemia and anemia in the study area, unveiling for the first time the association of asymptomatic malarial anemia with early clinical conversion from asymptomatic to symptomatic infection. Furthermore, these findings underscore the negative impact of asymptomatic malaria parasitemia on individual health, necessitating the development of appropriate control and preventive measures.

scholarly journals Differences in haematological parameters and haemoglobin phenotypes in symptomatic and asymptomatic subjects with Plasmodium falciparum infection in parts of Kaduna metropolis, Nigeria

2021 ◽  
Vol 22 (3) ◽  
pp. 407-414
Author(s):  
K.B. Dikwa ◽  
D.B. Maikaje ◽  
U.A. Yahaya ◽  
A.B. Suleiman
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Falciparum Malaria ◽  
Blood Film ◽  
Falciparum Infection ◽  
Haematological Parameters ◽  
Asymptomatic Malaria ◽  
Symptomatic Infection ◽  
Asymptomatic Individuals ◽  
Asymptomatic Subjects ◽  
Apparently Healthy

Background: Plasmodium falciparum is the leading cause of malaria morbidity and mortality in Nigeria with varied symptoms and haematological consequences. The objective of this study is to assess the differences in haematological parameters and haemoglobin phenotypes in symptomatic P. falciparum infected and apparently healthy asymptomatic individuals in parts of Kaduna metropolis.Methodology: A total of 1000 subjects; 500 symptomatic and 500 apparently healthy subjects asymptomatic for malaria, were recruited from selected hospitals and National Blood Bank in Kaduna metropolis. Blood samples were collected for thick and thin film microscopy to determine malaria parasitaemia and parasite species identification respectively. Haematological parameters were determined using automated blood analyser (KX-21N, Sysmex, Japan) and haemoglobin phenotypes by alkaline cellulose acetate electrophoresis.Results: Of the 1000 subjects recruited, 347 (34.7%) were positive for P. falciparum on blood film, which included 226 (45.2%) of 500 symptomatic and 121 (24.2%) of 500 asymptomatic subjects (p<0.00001). Of the 347 P. falciparum infected subjects, 275 (79.3%) had HbAA, 61 (17.6%) had HbAS, 1 (0.3%) had HbAC, 8 (2.3%) had HbSS, and 2 (0.6%) had HbSSf phenotypes. One hundred and sixty-three (72.1%) of the 226 symptomatic subjects had HbAA while 112 (92.6%) of the 121 asymptomatic subjects had HbAA, which indicated a significantly higher frequency of asymptomatic malaria in subjects with HbAA (p<0.00001). Conversely, 53 (23.5%) of the 226 symptomatic subjects had HbAS while 8 (6.6%) of 121 asymptomatic subjects had HbAS, indicating a significantly higher frequency of symptomatic malaria in subjects with HbAS (p=0.000086). The frequency of parasitaemia > 3,000 parasites/μL of blood was 100% for HbSSf, 25% for HbSS, 8.2% for HbAS and 2.2% for HbAA, which showed significantly higher frequency in subjects with HbSS (X2=7.5989, p=0.0054) and HbAS (X2=3.9627, p=0.046519) compared to HbAA. In symptomatic subjects, only MCHC value was significantly higher in subjects with HbAS (33.21±2.430) compared to those with HbAA (32.09 ±2.315) (p=0.003), while all other haematological parameters were not significantly different (p>0.05). In asymptomatic subjects, none of the haematological parameters was significantly different between subjects with HbAS and HbAA (p>0.05).Conclusion: Although the frequency of P. falciparum infection in this study is generally higher in subjects with HbAA, symptomatic infection and higher parasite density are associated with HbAS, HbSS and HbSSf. Effective utilisation of personal preventive measures by inhabitants, in addition to current malaria control and intervention strategies should be adequately implemented in Kaduna metropolis. Keywords: Haematological parameters, haemoglobin, electrophoresis, Plasmodium falciparum, malaria   Différences dans les paramètres hématologiques et les phénotypes d'hémoglobine chez les sujets symptomatiques et asymptomatiques atteints d'une infection à Plasmodium falciparum dans certaines parties de la métropole de Kaduna, Nigéria   Contexte: Plasmodium falciparum est la principale cause de morbidité et de mortalité liées au paludisme au Nigéria avec des symptômes et des conséquences hématologiques variés. L'objectif de cette étude est d'évaluer les différences de paramètres hématologiques et de phénotypes d'hémoglobine chez des individus symptomatiques infectés par P. falciparum et asymptomatiques apparemment en bonne santé dans certaines parties de la métropole de Kaduna. Méthodologie: Un total de 1000 sujets; 500 sujets symptomatiques et 500 sujets apparemment sains asymptomatiques pour le paludisme ont été recrutés dans certains hôpitaux et dans la Banque nationale du sang de la métropole de Kaduna. Des échantillons de sang ont été prélevés pour la microscopie à couche épaisse et mince afin de déterminer respectivement la parasitémie du paludisme et l'identification des espèces de parasites. Les paramètres hématologiques ont été déterminés à l'aide d'un analyseur sanguin automatisé (KX-21N, Sysmex, Japon) et des phénotypes d'hémoglobine par électrophorèse sur acétate de cellulose alcaline. Résultats: Sur les 1000 sujets recrutés, 347 (34,7%) étaient positifs pour P. falciparum sur frottis sanguin, qui comprenait 226 (45,2%) de 500 sujets symptomatiques et 121 (24,2%) de 500 sujets asymptomatiques (p<0,00001). Sur les 347 sujets infectés par P. falciparum, 275 (79,3%) avaient HbAA, 61 (17,6%) avaient HbAS, 1 (0,3%) avaient HbAC, 8 (2,3%) avaient HbSS et 2 (0,6%) avaient des phénotypes HbSSf. Cent soixante-trois (72,1%) des 226 sujets symptomatiques avaient une HbAA tandis que 112 (92,6%) des 121 sujets asymptomatiques avaient une HbAA, ce qui indiquait une fréquence significativement plus élevée de paludisme asymptomatique chez les sujets avec HbAA (p<0,00001). À l'inverse, 53 (23,5%) des 226 sujets symptomatiques avaient une HbAS tandis que 8 (6,6%) des 121 sujets asymptomatiques avaient une HbAS, indiquant une fréquence significativement plus élevée de paludisme symptomatique chez les sujets avec HbAS (p=0,000086). La fréquence de parasitémie> 3000 parasites / μL de sang était de 100% pour l'HbSSf, 25% pour l'HbSS, 8,2% pour l'HbAS et 2,2% pour l'HbAA, ce qui a montré une fréquence significativement plus élevée chez les sujets atteints d'HbSS (X2=7,5989, p=0,0054) et HbAS (X2=3,9627, p=0,046519) par rapport à l'HbAA. Chez les sujets symptomatiques, seule la valeur MCHC était significativement plus élevée chez les sujets avec HbAS (33,21±2,430) par rapport à ceux avec HbAA (32,09±2,315) (p=0,003), tandis que tous les autres paramètres hématologiques n'étaient pas significativement différents (p>0,05). Chez les sujets asymptomatiques, aucun des paramètres hématologiques n'était significativement différent entre les sujets avec HbAS et HbAA (p>0,05). Conclusion: Bien que la fréquence des infections à P. falciparum dans cette étude soit généralement plus élevée chez les sujets atteints d'HbAA, une infection symptomatique et une densité parasitaire plus élevée sont associées à l'HbAS, l'HbSS et l'HbSSf. Une utilisation efficace des mesures de prévention personnelle par les habitants, en plus des stratégies actuelles de lutte antipaludique et d'intervention, devrait être mise en oeuvre de manière adéquate dans la métropole de Kaduna. Mots clés: Paramètres hématologiques, hémoglobine, électrophorèse, Plasmodium falciparum, paludisme

scholarly journals High cases of submicroscopic Plasmodium falciparum infections in a suburban population of Lagos, Nigeria

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Florence A. Umunnakwe ◽  
Emmanuel T. Idowu ◽  
Olusola Ajibaye ◽  
Blessed Etoketim ◽  
Samuel Akindele ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Large Scale ◽  
Quantitative Polymerase Chain Reaction ◽  
Age Groups ◽  
Malaria Diagnosis ◽  
School Age Children ◽  
Asymptomatic Malaria ◽  
High Prevalence ◽  
Study Population ◽  
Low Sensitivity

Abstract Background Asymptomatic malaria parasites are significant sources of infections for onward malaria transmission. Conventional tools for malaria diagnosis such as microscopy and rapid diagnostic test kits (RDT) have relatively low sensitivity, hence the need for alternative tools for active screening of such low-density infections. Methods This study tested var acidic terminal sequence-based (varATS) quantitative polymerase chain reaction (qPCR) for screening asymptomatic Plasmodium falciparum infections among dwellers of a sub-urban community in Lagos, Nigeria. Clinically healthy participants were screened for malaria using microscopy, RDT and varATS qPCR techniques. Participants were stratified into three age groups: 1–5, 6–14 and > 14 years old. Results Of the 316 participants screened for asymptomatic malaria infection, 78 (24.68%) were positive by microscopy, 99 (31.33%) were positive by RDT and 112 (35.44%) by varATS qPCR. Participants aged 6–14 years had the highest prevalence of asymptomatic malaria, with geometric means of ~ 116 parasites/µL and ~ 6689 parasites/µL as detected by microscopy and varATS, respectively. Conclusion This study has revealed high prevalence of asymptomatic malaria in the study population, with varATS detecting additional sub-microscopic infections. The highest concentration of asymptomatic malaria was observed among school-age children between 6 and 14 years old. A large-scale screening to identify other potential hotspots of asymptomatic parasites in the country is recommended.

Prevalence of Mutant Alleles Responsible for Chloroquine Resistance among Plasmodium falciparum Isolates in North Central, Nigeria

2019 ◽  
pp. 1-8
Author(s):  
H. A. Edogun ◽  
G. O. Daramola ◽  
A. O. Ojerinde ◽  
C. O. Esan ◽  
A. T. Adegbuyi ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Artemisinin Combination Therapy ◽  
Chloroquine Resistance ◽  
Current Status ◽  
Self Medication ◽  
Nested Polymerase Chain Reaction ◽  
Chloroquine Resistance Transporter ◽  
Whatman Filter Paper ◽  
High Prevalence ◽  
Detection Of Mutations

Background: Although chloroquine (CQ) has been officially replaced with artemisinin combination therapy (ACT) as first line drug for the treatment of malaria in Nigeria since 2005, a lot of people still believe that chloroquine is more effective chiefly because of the decline in the sensitivity of Plasmodium falciparum to ACT. Thus resulting into unofficial use of CQ for self medication. This study was conducted in order to survey the current status of chloroquine resistant strains of pfcrt and pfmdr1 in view of possible re-introduction of chloroquine for malaria treatment. Methods: DNA was extracted from one hundred (100) microscopically confirmed Plasmodium falciparum positive blood samples spotted on 3 mm Whatman filter paper. The detection of mutations in Plasmodium falciparum chloroquine resistance transporter (Pfcrt) and Plasmodium falciparum multidrug resistance (Pfmdr1) genes was performed by nested polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP). Results: Results showed the presence of mutant alleles of Pfcrt and Pfmdr1 in 60% and 41% of the samples respectively. However, there was no significant correlation in the prevalence of mutant alleles (T76/Y86) in relation to gender (p = 0.59/ 0.08) and age (p=0.59/0.93) of participants respectively. Conclusion: The observed high prevalence of chloroquine resistance despite thirteen years of withdrawal calls for serious concern.

scholarly journals High prevalence of asymptomatic malaria infections in adults, Ashanti Region, Ghana, 2018

2020 ◽  
Author(s):  
Melina Heinemann ◽  
Richard O. Phillips ◽  
Christof D. Vinnemeier ◽  
Christina Rolling ◽  
Egbert Tannich ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Malariae ◽  
Asymptomatic Malaria ◽  
Plasmodium Ovale ◽  
Forest Zone ◽  
Ashanti Region ◽  
Plasmodium Ovale Curtisi ◽  
High Prevalence ◽  
Asymptomatic Adult ◽  
Species Specific

Abstract Background Ghana is among the high-burden countries for malaria infection and recently reported a notably increase in malaria cases. While asymptomatic parasitemia is increasingly recognized as a hurdle for malaria elimination, studies on asymptomatic malaria are scarce and usually focus on children and on non-falciparum species. The present study aims to assess the prevalence of asymptomatic Plasmodium falciparum and non-falciparum infections in Ghanaian adults in the Ashanti region during the high transmission season. Methods Asymptomatic adult residents from five villages in the Ashanti Region, Ghana, were screened for Plasmodium spp. by rapid diagnostic test (RDT) and polymerase chain reaction (PCR) during the rainy season. Samples tested positive were subtyped using species-specific real-time PCR. For all P. ovale infections additional sub-species identification was performed.Results Molecular prevalence of asymptomatic Plasmodium infection was 284/391 (73%); only 126 (32%) infections were detected by RDT. While 266 (68%) participants were infected with Plasmodium falciparum, 33 (8%) were infected with Plasmodium malariae and 34 (9%) with Plasmodium ovale. The sub-species Plasmodium ovale curtisi and P. ovale wallikeri were identified to similar proportions. Non-falciparum infections usually presented as mixed infections with Plasmodium falciparum.Conclusions Most adult residents in the Ghanaian forest zone are asymptomatic Plasmodium carriers. The high Plasmodium prevalence not detected by RDT in adults highlights that malaria eradication efforts must target all members of the population. Beneath Plasmodium falciparum, screening and treatment must also include infections with Plasmodium malariae, P. ovale curtisi and P. ovale wallikeri .

scholarly journals High prevalence of asymptomatic malaria infections in adults, Ashanti Region, Ghana, 2018

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Melina Heinemann ◽  
Richard O. Phillips ◽  
Christof D. Vinnemeier ◽  
Christina C. Rolling ◽  
Egbert Tannich ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Malariae ◽  
Asymptomatic Malaria ◽  
Forest Zone ◽  
Transmission Season ◽  
Ashanti Region ◽  
High Prevalence ◽  
Notable Increase ◽  
Asymptomatic Adult ◽  
Species Specific

Abstract Background Ghana is among the high-burden countries for malaria infections and recently reported a notable increase in malaria cases. While asymptomatic parasitaemia is increasingly recognized as a hurdle for malaria elimination, studies on asymptomatic malaria are scarce, and usually focus on children and on non-falciparum species. The present study aims to assess the prevalence of asymptomatic Plasmodium falciparum and non-falciparum infections in Ghanaian adults in the Ashanti region during the high transmission season. Methods Asymptomatic adult residents from five villages in the Ashanti Region, Ghana, were screened for Plasmodium species by rapid diagnostic test (RDT) and polymerase chain reaction (PCR) during the rainy season. Samples tested positive were subtyped using species-specific real-time PCR. For all Plasmodium ovale infections additional sub-species identification was performed. Results Molecular prevalence of asymptomatic Plasmodium infection was 284/391 (73%); only 126 (32%) infections were detected by RDT. While 266 (68%) participants were infected with Plasmodium falciparum, 33 (8%) were infected with Plasmodium malariae and 34 (9%) with P. ovale. The sub-species P. ovale curtisi and P. ovale wallikeri were identified to similar proportions. Non-falciparum infections usually presented as mixed infections with P. falciparum. Conclusions Most adult residents in the Ghanaian forest zone are asymptomatic Plasmodium carriers. The high Plasmodium prevalence not detected by RDT in adults highlights that malaria eradication efforts must target all members of the population. Beneath Plasmodium falciparum, screening and treatment must also include infections with P. malariae, P. o. curtisi and P. o. wallikeri.

scholarly journals High prevalence of asymptomatic malaria infections in adults, Ashanti Region, Ghana, 2018

2020 ◽  
Author(s):  
Melina Heinemann ◽  
Richard O. Phillips ◽  
Christof D. Vinnemeier ◽  
Christina Rolling ◽  
Egbert Tannich ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Species ◽  
Plasmodium Malariae ◽  
Asymptomatic Malaria ◽  
Forest Zone ◽  
Transmission Season ◽  
Ashanti Region ◽  
High Prevalence ◽  
Asymptomatic Adult ◽  
Species Specific

Abstract Background Ghana is among the high-burden countries for malaria infection and recently reported a notably increase in malaria cases. While asymptomatic parasitaemia is increasingly recognized as a hurdle for malaria elimination, studies on asymptomatic malaria are scarce and usually focus on children and on non-falciparum species. The present study aims to assess the prevalence of asymptomatic Plasmodium falciparum and non-falciparum infections in Ghanaian adults in the Ashanti region during the high transmission season. Methods Asymptomatic adult residents from five villages in the Ashanti Region, Ghana, were screened for Plasmodium species by rapid diagnostic test (RDT) and polymerase chain reaction (PCR) during the rainy season. Samples tested positive were subtyped using species-specific real-time PCR. For all Plasmodium ovale infections additional sub-species identification was performed. Results Molecular prevalence of asymptomatic Plasmodium infection was 284/391 (73%); only 126 (32%) infections were detected by RDT. While 266 (68%) participants were infected with Plasmodium falciparum, 33 (8%) were infected with Plasmodium malariae and 34 (9%) with P. ovale. The sub-species P. ovale curtisi and P. ovale wallikeri were identified to similar proportions. Non-falciparum infections usually presented as mixed infections with P. falciparum. Conclusions Most adult residents in the Ghanaian forest zone are asymptomatic Plasmodium carriers. The high Plasmodium prevalence not detected by RDT in adults highlights that malaria eradication efforts must target all members of the population. Beneath Plasmodium falciparum, screening and treatment must also include infections with P. malariae, P. o. curtisi and P. o. wallikeri.

Understanding the Impact of Bullying in a Unionized U.S. Public Sector Workforce

2019 ◽  
Vol 68 (3) ◽  
pp. 139-153 ◽  
Author(s):  
Mazen El Ghaziri ◽  
Shellie Simons ◽  
Jane Lipscomb ◽  
Carla L. Storr ◽  
Kathleen McPhaul ◽  
...  
Keyword(s):  
Public Sector ◽  
Organizational Climate ◽  
Negative Impact ◽  
Multinomial Logistic Regression ◽  
Female Gender ◽  
Bargaining Unit ◽  
Organizational Level ◽  
Organizational Impact ◽  
Cross Sectional ◽  
The Impact

Background: Workplace Bullying (WPB) can have a tremendous, negative impact on the victims and the organization as a whole. The purpose of this study was to examine individual and organizational impact associated with exposure to bullying in a large U.S. unionized public sector workforce. Methods: A cross-sectional Web-based survey was conducted among 16,492 U.S. state government workers. Survey domains included demographics, negative acts (NAs) and bullying, supportiveness of the organizational climate, and individual and organizational impacts of bullying. Multinomial logistic regression was used to assess the impact among respondents who reported exposure to bullying. Findings: A total of 72% participants responded to the survey (n = 11,874), with 43.7% (n = 5,181) reporting exposure to NAs and bullying. A total of 40% (n = 4,711) participants who experienced WPB reported individual impact(s) while 42% ( n = 4,969) reported organization impact(s). Regular NA was associated with high individual impact (negatively impacted them personally; odds ratio [OR] = 5.03) when controlling for other covariates including: female gender (OR =1.89) and job tenure of 6 to 10 years (OR = 1.95); working in a supportive organizational climate and membership in a supportive bargaining unit were protective of high impact (OR = 0.04 and OR = 0.59, respectively). High organizational impact (transferring to another position) was associated with regular NA and bullying (OR = 16.26), female gender (OR = 1.55), providing health care and field service (OR = 1.68), and protective effect of organizational climate (OR = 0.39). We found a dose-response relationship between bullying and both individual and organizational-level impact. Conclusion/Application to Practice: Understanding the impacts of WPB should serve to motivate more workplaces and unions to implement effective interventions to ameliorate the problem by enhancing the organizational climate, as well as management and employee training on the nature of WPB and guidance on reporting.

scholarly journals Genetic diversity and population structure of Plasmodium falciparum in Nigeria: insights from microsatellite loci analysis

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Fehintola V. Ajogbasile ◽  
Adeyemi T. Kayode ◽  
Paul E. Oluniyi ◽  
Kazeem O. Akano ◽  
Jessica N. Uwanibe ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Plasmodium Falciparum ◽  
Population Structure ◽  
Microsatellite Loci ◽  
Control Strategies ◽  
Population Diversity ◽  
Parasite Population ◽  
Nested Polymerase Chain Reaction ◽  
Public Health Burden ◽  
Genetic Diversity And Structure

Abstract Background Malaria remains a public health burden especially in Nigeria. To develop new malaria control and elimination strategies or refine existing ones, understanding parasite population diversity and transmission patterns is crucial. Methods In this study, characterization of the parasite diversity and structure of Plasmodium falciparum isolates from 633 dried blood spot samples in Nigeria was carried out using 12 microsatellite loci of P. falciparum. These microsatellite loci were amplified via semi-nested polymerase chain reaction (PCR) and fragments were analysed using population genetic tools. Results Estimates of parasite genetic diversity, such as mean number of different alleles (13.52), effective alleles (7.13), allelic richness (11.15) and expected heterozygosity (0.804), were high. Overall linkage disequilibrium was weak (0.006, P < 0.001). Parasite population structure was low (Fst: 0.008–0.105, AMOVA: 0.039). Conclusion The high level of parasite genetic diversity and low population structuring in this study suggests that parasite populations circulating in Nigeria are homogenous. However, higher resolution methods, such as the 24 SNP barcode and whole genome sequencing, may capture more specific parasite genetic signatures circulating in the country. The results obtained can be used as a baseline for parasite genetic diversity and structure, aiding in the formulation of appropriate therapeutic and control strategies in Nigeria.

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