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.

scholarly journals The epidemiology and detectability of asymptomatic Plasmodium vivax and Plasmodium falciparum infections in low, moderate and high transmission settings in Ethiopia

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Elifaged Hailemeskel ◽  
Surafel K Tebeje ◽  
Sinknesh W. Behaksra ◽  
Girma Shumie ◽  
Getasew Shitaye ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Vivax ◽  
Age Groups ◽  
Diagnostic Tools ◽  
Asymptomatic Malaria ◽  
Rapid Diagnostics ◽  
Cross Sectional ◽  
Low Transmission ◽  
High Transmission ◽  
Study Sites

Abstract Background As countries move to malaria elimination, detecting and targeting asymptomatic malaria infections might be needed. Here, the epidemiology and detectability of asymptomatic Plasmodium falciparum and Plasmodium vivax infections were investigated in different transmission settings in Ethiopia. Method: A total of 1093 dried blood spot (DBS) samples were collected from afebrile and apparently healthy individuals across ten study sites in Ethiopia from 2016 to 2020. Of these, 862 were from community and 231 from school based cross-sectional surveys. Malaria infection status was determined by microscopy or rapid diagnostics tests (RDT) and 18S rRNA-based nested PCR (nPCR). The annual parasite index (API) was used to classify endemicity as low (API > 0 and < 5), moderate (API ≥ 5 and < 100) and high transmission (API ≥ 100) and detectability of infections was assessed in these settings. Results In community surveys, the overall prevalence of asymptomatic Plasmodium infections by microscopy/RDT, nPCR and all methods combined was 12.2% (105/860), 21.6% (183/846) and 24.1% (208/862), respectively. The proportion of nPCR positive infections that was detectable by microscopy/RDT was 48.7% (73/150) for P. falciparum and 4.6% (2/44) for P. vivax. Compared to low transmission settings, the likelihood of detecting infections by microscopy/RDT was increased in moderate (Adjusted odds ratio [AOR]: 3.4; 95% confidence interval [95% CI] 1.6–7.2, P = 0.002) and high endemic settings (AOR = 5.1; 95% CI 2.6–9.9, P < 0.001). After adjustment for site and correlation between observations from the same survey, the likelihood of detecting asymptomatic infections by microscopy/RDT (AOR per year increase = 0.95, 95% CI 0.9–1.0, P = 0.013) declined with age. Conclusions Conventional diagnostics missed nearly half of the asymptomatic Plasmodium reservoir detected by nPCR. The detectability of infections was particularly low in older age groups and low transmission settings. These findings highlight the need for sensitive diagnostic tools to detect the entire parasite reservoir and potential infection transmitters.

scholarly journals Prevalence of Intestinal Parasitic Infection in Relation to Age in the Urban Population from Chandigarh, India

2021 ◽  
pp. 51-56
Author(s):  
Manjula Mehta ◽  
Sonia Bhonchal Bhardwaj ◽  
Jyoti Sharma
Keyword(s):  
Urban Population ◽  
Human Subjects ◽  
Parasitic Infection ◽  
Age Groups ◽  
Control Measures ◽  
Age Group ◽  
Intestinal Parasitic Infection ◽  
Intestinal Parasitosis ◽  
High Prevalence ◽  
Study Population

Background: Intestinal parasitic infection is a global health problem particularly in the developing countries with different prevalence rates in different regions. The aim of this study was to evaluate the prevalence of intestinal parasitic infection in different age groups in the urban population of Chandigarh, India. Materials and Methods: The retrospective study included stool samples 504 in number from human subjects from Chandigarh. Unstained wet saline mount preparations of stool sample were done to detect eggs or larvae and iodine wet mount to detect ova/ cysts of tapeworm, Enterobius, Ascaris, Giardia, Trichuris and Hookworm. Results: A high prevalence rate of intestinal parasitosis (73%) was seen. The age group distribution shows a higher prevalence of intestinal parasitic infection in the young population (age group 21-30 years and 31-40 years). Ascariasis was the most common parasitic infection observed. Conclusion: The present study reveals a high prevalence of intestinal parasitic infection in the study population and calls for long term control measures to improve their sanitary and living conditions.

Immune responses during helminth-malaria co-infection: a pilot study in Ghanaian school children

Parasitology ◽  
2008 ◽  
Vol 135 (7) ◽  
pp. 855-860 ◽  
Author(s):  
FRANCA C. HARTGERS ◽  
BENEDICTA B. OBENG ◽  
DANIEL BOAKYE ◽  
MARIA YAZDANBAKHSH
Keyword(s):  
Plasmodium Falciparum ◽  
Pilot Study ◽  
School Children ◽  
Human Populations ◽  
Immunological Parameters ◽  
Helminth Infections ◽  
High Prevalence ◽  
Study Population ◽  
Tropical Areas ◽  
Underlying Mechanisms

SUMMARYMalaria and helminth infections have a shared geographical distribution and therefore co-infections are frequent in tropical areas of the world. Human populations of helminth and malaria co-infection have shown contradictory results for the course of malarial infection and disease, possibly depending on the type of helminth studied, the intensity of helminth infection and the age of the study population. Although immunological studies might clarify the underlying mechanisms of protection or increased susceptibility, there are very few studies that have looked at immunological parameters in helminth and malaria co-infection. After discussing the available immunological data on co-infection, we describe a pilot study performed in Ghanaian school children where we compare anti-malarial responses in children living in an urban area, where the prevalence of helminth andPlasmodium falciparuminfections was low, with that of children living in a rural area with high prevalence of helminth andPlasmodium falciparuminfections.

scholarly journals The Epidemiology and Detectability of Asymptomatic Plasmodium Vivax and Plasmodium Falciparum Infections in Low, Moderate and High Transmission Settings in Ethiopia 

2020 ◽  
Author(s):  
Elifaged Hailemeskel ◽  
Surafel K Tebeje ◽  
Sinknesh Behaksra ◽  
Girma Shumie ◽  
Getasew Shitaye ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Age Groups ◽  
Diagnostic Tools ◽  
Asymptomatic Malaria ◽  
Rapid Diagnostics ◽  
Cross Sectional ◽  
Low Transmission ◽  
High Transmission ◽  
School Based ◽  
Study Sites

Abstract Background: As countries move to malaria elimination, detecting and targeting asymptomatic malaria infections might be needed. Here, we investigated the epidemiology and detectability of asymptomatic Plasmodium falciparum and P. vivax infections in different transmission settings in Ethiopia.Method: A total of 1093 dried blood spot (DBS) samples were collected from afebrile and apparently healthy individuals across ten study sites in Ethiopia from 2016 to 2020. Of these, 862 were from community and 231 from school based cross-sectional surveys. Malaria infection status was determined by microscopy or rapid diagnostics tests (RDT) and 18S rRNA based nested PCR (nPCR). The annual parasite index (API) was used to classify endemicity as low (API>0 and<5), moderate (API ≥5 and <100) and high transmission (API≥100) and detectability of infections was assessed in these settings. Results: In community surveys, the overall prevalence of asymptomatic Plasmodium infections by microscopy/RDT, nPCR and all methods combined was 12.2% (105/860), 21.6% (183/846) and 24.1% (208/862), respectively. The proportion of nPCR positive infections that was detectable by microscopy/RDT was 48.7% (73/150) for P. falciparum and 4.6% (2/44) for P. vivax. Compared to low transmission settings, the likelihood of detecting infections by microscopy/RDT was increased in moderate (Adjusted odds ratio [AOR]: 3.4; 95% confidence interval [95%CI]:1.6-7.2, P=0.002) and high endemic settings (AOR=5.1; 95%CI=2.6-9.9, P<0.001). After adjustment for site and correlation between observations from the same survey, the likelihood of detecting asymptomatic infections by microscopy/RDT (AOR per year increase = 0.95, 95%CI=0.9-1.0, P=0.013) declined with age.Conclusion: Conventional diagnostics missed nearly half of the asymptomatic Plasmodium reservoir detected by nPCR. The detectability of infections was particularly low in older age groups and low transmission settings. These findings highlight the need for sensitive diagnostic tools to detect the entire parasite reservoir and potential infection transmitters.

scholarly journals Usefulness of Polymerase Chain Reaction in the diagnosis of asymptomatic malaria among school age children in Ilorin, Nigeria

2018 ◽  
Vol 1 (1) ◽  
pp. 39-45
Author(s):  
Ayodele Adedoja ◽  
Shola Kola Babatunde ◽  
Bukola Deborah Tijani ◽  
Ajibola A. Akanbi II ◽  
Olusola Ojurongbe
Keyword(s):  
Polymerase Chain Reaction ◽  
Plasmodium Species ◽  
Malaria Diagnosis ◽  
School Age Children ◽  
Clinical Settings ◽  
Asymptomatic Malaria ◽  
Chain Reaction ◽  
Malaria Species ◽  
Pcr Method ◽  
Polymerase Chain

Introduction: In Nigeria, microscopy and Rapid Diagnostic Tests (RDTs) are majorly used routinely to diagnose malaria in clinical settings. In recent years, molecular diagnosis has emerged as the most sensitive method for malaria diagnosis. This study determined the usefulness of Polymerase Chain Reaction (PCR) in comparison to microscopy (Giemsa stained thick and thin smears) for the diagnosis of asymptomatic malaria in Ilorin, Nigeria. Methods: Th e study enrolled 310 school children aged 4–15 years with no sign or symptoms of malaria. Blood samples were collected for identification of Plasmodium species infection using light microscopy and conventional PCR. Results: The PCR method detected m o r e infection of P. falciparum 107 (34.5%) than slide microscopy 81 (26.1%) in the study. Only P. falciparum was detected by microscopy while PCR detected mono infection of P. malariae (3.2%) and P. ovale (0.6%) and mixed infection of P. falciparum and P. malariae (3.2%). Overall the PCR method detected more malaria parasite compared to microscopy. Conclusion: The PCR technique, although more laborious and expensive than microscopy, have better diagnostic accuracy and are highly useful for the detection of P. falciparum and other malaria species in asymptomatic and low parasitaemia cases.

Study of Vitamin D Deficiency in Adolescent Females (10-18 years old) In Cairo

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
R M Botros ◽  
Y M Eid ◽  
B M Mostafa ◽  
Y H E Elmeligy
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Large Scale ◽  
Age Groups ◽  
Sun Exposure ◽  
Adolescent Females ◽  
Contributing Factors ◽  
Significant Difference ◽  
High Prevalence ◽  
Deficient Group

Abstract Background Vitamin D deficiency is a common problem among Egyptian females across all age groups, for whom contributing factors include inadequate sun exposure possibly related to cultural/social factors, and insufficient dietary calcium, wearing a sunscreen reduces vitamin D synthesis in the skin by more than 95%. Not only environmental factors, such as sun exposure and nutrition, but also genetic and possibly also epigenetic factors are determinants of serum 25(OH) D. Aim We sought to determine the frequency of occurrence of vit D deficiency in Egyptian adolescent females aged 10-18 years in Cairo. Methods Study was conducted on 90 healthy adult females aged (10-18) years and classified them into: Sufficient group: with vitamin D level &gt;30ng/ml, (40%) of participants. Mild deficient group: with vitamin D level between 21-29ng/ml (14.44%) of participants. Moderate deficient group: with vitamin D level between 10-20ng/ml (11.11%) of participants. Severe deficient group: with vitamin D level &lt;10ng/ml (34.44%) of participants. Results Our study showed a high prevalence of low vitamin D level among healthy adolescent females aged (10-18) years old. There were a significant difference On comparing vitamin D status groups as regard vitamin D rich food intake, duration of sun exposure and height for age (p &lt; 0.001), (p &lt; 0.001) and (p = 0.012) respectively. There were significant difference on comparing vit D status groups with s.Ca, PTH and Alk.Ph (p &lt; 0.001). Conclusion Vitamin D deficiency became endemic in Egypt. Large-scale studies are needed to properly evaluate the size of the problem.

scholarly journals Seroprevalence of Immunoglobulin G Antibody among Contacts of COVID19 Cases: A Study from India

2021 ◽  
Author(s):  
Om Prakash ◽  
Bhavin Solanki ◽  
Jay Sheth ◽  
Mehul Acharya ◽  
Mina Kadam ◽  
...  
Keyword(s):  
Immunoglobulin G ◽  
Large Scale ◽  
Age Groups ◽  
Population Based ◽  
Contact Tracing ◽  
Enzyme Linked Immunosorbent Assay ◽  
P Value ◽  
Different Types ◽  
The Difference ◽  
Low Sensitivity

Objective: To estimate Covid19 seropositivity among contacts of cases and to compare the seropositivity among different types of contact for assessing the differential risk & transmission dynamics.Material and Methods: A large-scale population-based serosurvey was carried out among the general population of Ahmedabad during the second half of October 2020. The contacts of cases were selected based on the population proportion and enrolled as an additional category. The seropositivity among the contacts was estimated using the enzyme-linked immunosorbent assay and compared with different types of contact and available demographic factors.Results: As of October 2020, the seropositivity against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV2) among contacts of cases in Ahmedabad was 26.0% [95% confidence interval 24.2–28.0]. The seropositivity among family contacts was significantly higher (28.8%) compared to other contacts (24.4%) (Z=2.19, p-value=0.028). This trend was seen across all age groups and both sexes. The seropositivity was higher among females (27.7%) compared to males (24.5%) but the difference was statistically not significant (Z=1.64, p-value=0.101). In terms of age groups, the positivity had an increasing trend up to 60 years but declined after that.Conclusion: A seropositivity of 26.0% among contacts indicates that a large proportion of contacts demonstrated Immunoglobulin-G antibodies. This highlights asymptomatic transmission and/or low sensitivity of the diagnostic tests. The current strategy for contact tracing and testing among contacts is justified based on the significantly higher seropositivity among family contacts.

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 .

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