scholarly journals Variation of prevalence of malaria, parasite density and the multiplicity of Plasmodium falciparum infection throughout the year at three different health centers in Brazzaville, Republic of Congo

2020 ◽  
Author(s):  
- PEMBE ISSAMOU MAYENGUE ◽  
Dezi Kouhounina Batsimba ◽  
Roch Fabien Niama ◽  
Reyna Ibara Ottia ◽  
Alida Malonga-Massanga ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
Parasite Density ◽  
Santé Publique ◽  
Falciparum Infection ◽  
P Value ◽  
Multiplicity Of Infection ◽  
Different Seasons ◽  
Dry Seasons ◽  
Sante Publique

Abstract Background: In the Republic of Congo, hot temperature and seasons distortions observed may impact the development of malaria parasites. We investigate the variation of malaria cases, parasite density and the multiplicity of Plasmodium falciparum infection throughout the year in Brazzaville. Methods: From May 2015 to May 2016, suspected patients with uncomplicated malaria were enrolled at the Hôpital de Mfilou, CSI « Maman Mboualé», and the Laboratoire National de Santé Publique. For each patient, thick blood was examined and parasite density was calculated. After DNA isolation, MSP1 and MSP2 genes were genotyped.Results : A total of 416, 259 and 131 patients with suspected malaria were enrolled at the CSI «Maman Mboualé», Hôpital de Mfilou and the Laboratoire National de Santé Publique respectively. Proportion of malaria cases and geometric mean parasite density were higher at the CSI «Maman Mboualé» compared to over sites (P-value ˂0.001). However the multiplicity of infection was higher at the Hôpital de Mfilou ( P-value ˂0.001). At the Laboratoire National de Santé Publique, malaria cases and multiplicity of infection were not influenced by different seasons. However, variation of the mean parasite density was statistically significant ( P-value ˂0.01). Higher proportions of malaria cases were found at the end of main rainy season either the beginning of the main dry season at the Hôpital de Mfilou and the CSI «Maman Mboualé»; while, lowest proportions were observed in September and January and in September and March respectively. Higher mean parasite densities were found at the end of rainy seasons with persistence at the beginning of dry seasons. Lowest mean parasite densities were found during dry seasons, with persistence at the beginning of rainy seasons. Fluctuation of the multiplicity of infection throughout the year was observed without significance between seasons.Conclusion: The current study suggests that malaria transmission is still variable between the north and south parts of Brazzaville. Seasonal fluctuations of malaria cases and mean parasite densities were observed with some extension to different seasons. Thus, both meteorological and entomological studies are needed to update the season’s periods as well as malaria transmission intensity in Brazzaville.

scholarly journals Variation of prevalence of malaria, parasite density and the multiplicity of Plasmodium falciparum infection throughout the year at three different health centers in Brazzaville, Republic of Congo

2019 ◽  
Author(s):  
- PEMBE ISSAMOU MAYENGUE ◽  
Dezi Kouhounina Batsimba ◽  
Roch Fabien Niama ◽  
Reyna Ibara Ottia ◽  
Alida Malonga-Massanga ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
Parasite Density ◽  
Santé Publique ◽  
Falciparum Infection ◽  
P Value ◽  
Multiplicity Of Infection ◽  
Different Seasons ◽  
Dry Seasons ◽  
Sante Publique

Abstract Background: In the Republic of Congo, hot temperature and seasons distortions observed may impact the development of malaria parasites. We investigate the variation of malaria cases, parasite density and the multiplicity of Plasmodium falciparum infection throughout the year in Brazzaville. Methods: From May 2015 to May 2016, suspected patients with uncomplicated malaria were enrolled at the Hôpital de Mfilou, CSI « Maman Mboualé», and the Laboratoire National de Santé Publique. For each patient, thick blood was examined and parasite density was calculated. After DNA isolation, MSP1 and MSP2 genes were genotyped. Results: A total of 416, 259 and 131 patients with suspected malaria were enrolled at the CSI «Maman Mboualé», Hôpital de Mfilou and the Laboratoire National de Santé Publique respectively. Proportion of malaria cases and geometric mean parasite density were higher at the CSI «Maman Mboualé» compared to over sites (P-value ˂0.001). However the multiplicity of infection was higher at the Hôpital de Mfilou (P-value ˂0.001). At the Laboratoire National de Santé Publique, malaria cases and multiplicity of infection were not influenced by different seasons. However, variation of the mean parasite density was statistically significant (P-value ˂0.01). Higher proportions of malaria cases were found at the end of main rainy season either the beginning of the main dry season at the Hôpital de Mfilou and the CSI «Maman Mboualé»; while, lowest proportions were observed in September and January and in September and March respectively. Higher mean parasite densities were found at the end of rainy seasons with persistence at the beginning of dry seasons. The lowest mean parasite densities were found during dry seasons, with persistence at the beginning of rainy seasons. Fluctuation of the multiplicity of infection throughout the year was observed without significance between seasons. Conclusion: The current study suggests that malaria transmission is still variable between the north and south parts of Brazzaville. Seasonal fluctuations of malaria cases and mean parasite densities were observed with some extension to different seasons. Thus, both meteorological and entomological studies are needed to update the season’s periods as well as malaria transmission intensity in Brazzaville.

scholarly journals Variation of malaria cases, parasite density and the multiplicity of Plasmodium falciparum infection throughout the year at three different health centers in Brazzaville, Republic of Congo

2019 ◽  
Author(s):  
- PEMBE ISSAMOU MAYENGUE ◽  
Dezi Kouhounina Batsimba ◽  
Roch Fabien Niama ◽  
Reyna Ibara Ottia ◽  
Alida Malonga-Massanga ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
Parasite Density ◽  
Santé Publique ◽  
Falciparum Infection ◽  
P Value ◽  
Multiplicity Of Infection ◽  
Different Seasons ◽  
Dry Seasons ◽  
Sante Publique

Abstract Background: In the Republic of Congo, hot temperature and seasons distortions observed may impact seasonal variations of the development of malaria parasites. We investigate the variation of malaria cases, parasite density and the multiplicity of Plasmodium falciparum infection throughout the year in Brazzaville. Methods: From May 2015 to May 2016, suspected patients with uncomplicated malaria were enrolled at the Hôpital de Mfilou, CSI « Maman Mboualé», and the Laboratoire National de Santé Publique. For each patient, thick blood was examined and parasite density was calculated. After DNA isolation, MSP1 and MSP2 genes were genotyped. Results: A total of 416, 259 and 131 patients with suspected malaria were enrolled at the CSI «Maman Mboualé», Hôpital de Mfilou and the Laboratoire National de Santé Publique respectively. Proportion of malaria cases and geometric mean parasite density were higher at the CSI «Maman Mboualé» compared to over sites (P-value ˂0.001). However the multiplicity of infection was higher at the Hôpital de Mfilou (P-value ˂0.001). At the Laboratoire National de Santé Publique, malaria cases and multiplicity of infection were not influenced by different seasons. However, variation of the mean parasite density was statistically significant (P-value ˂0.01). Higher proportions of malaria cases were found at the end of main rainy season including the beginning of the main dry season at the Hôpital de Mfilou and the CSI «Maman Mboualé»; while, lowest proportions were observed in September and January and in September and March respectively. Higher mean parasite densities were found at the end of rainy seasons with persistence at the beginning of dry seasons. The lowest mean parasite densities were found during dry seasons, with persistence at the beginning of rainy seasons. Fluctuation of the multiplicity of infection throughout the year was observed without any impact of different seasons. Conclusion: The current study suggests that malaria transmission is still variable between the north and south parts of Brazzaville. Seasonal fluctuations of malaria cases and mean parasite densities were observed with some extension to different seasons. Thus, both meteorological and entomological studies are needed to update the season’s periods as well as malaria transmission intensity in Brazzaville.

scholarly journals The Diversity, Multiplicity of Infection and Population Structure of P. falciparum Parasites Circulating in Asymptomatic Carriers Living in High and Low Malaria Transmission Settings of Ghana

Genes ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 434 ◽  
Author(s):  
Zakaria Abukari ◽  
Ruth Okonu ◽  
Samuel B. Nyarko ◽  
Aminata C. Lo ◽  
Cheikh C. Dieng ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Population Structure ◽  
Malaria Transmission ◽  
Parasite Prevalence ◽  
Transmission Intensity ◽  
Multiplicity Of Infection ◽  
Malaria Transmission Intensity ◽  
Ms Analysis ◽  
Greater Accra Region ◽  
Low Malaria Transmission

Background: Diversity in Plasmodium falciparum poses a major threat to malaria control and elimination interventions. This study utilized 12 polymorphic microsatellite (MS) markers and the Msp2 marker to examine diversity, multiplicity of infection (MOI) as well as the population structure of parasites circulating in two sites separated by about 92 km and with varying malaria transmission intensities within the Greater Accra Region of Ghana. Methods: The diversity and MOI of P. falciparum parasites in 160 non-symptomatic volunteers living in Obom (high malaria transmission intensity) and Asutsuare (low malaria transmission intensity) aged between 8 and 60 years was determined using Msp2 genotyping and microsatellite analysis. Results: The prevalence of asymptomatic P. falciparum carriers as well as the parasite density of infections was significantly higher in Obom than in Asutsuare. Samples from Asutsuare and Obom were 100% and 65% clonal, respectively, by Msp2 genotyping but decreased to 50% and 5%, respectively, when determined by MS analysis. The genetic composition of parasites from Obom and Asutsuare were highly distinct, with parasites from Obom being more diverse than those from Asutsuare. Conclusion: Plasmodium falciparum parasites circulating in Obom are genetically more diverse and distinct from those circulating in Asutsuare. The MOI in samples from both Obom and Asutsuare increased when assessed by MS analysis relative to MSP2 genotyping. The TA40 and TA87 loci are useful markers for estimating MOI in high and low parasite prevalence settings.

scholarly journals Impact of an Irrigation Dam on the Transmission and Diversity of Plasmodium falciparum in a Seasonal Malaria Transmission Area of Northern Ghana

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Eric Kyei-Baafour ◽  
Bernard Tornyigah ◽  
Benjamin Buade ◽  
Langbong Bimi ◽  
Abraham R. Oduro ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
Parasite Density ◽  
Parasite Prevalence ◽  
Dry Season ◽  
Water Bodies ◽  
Northern Ghana ◽  
Wet Season ◽  
Transmission Area ◽  
Dam Site

Water bodies such as dams are known to alter the local transmission patterns of a number of infectious diseases, especially those transmitted by insects and other arthropod vectors. The impact of an irrigation dam on submicroscopic asexual parasite carriage in individuals living in a seasonal malaria transmission area of northern Ghana was investigated. A total of 288 archived DNA samples from two cross-sectional surveys in two communities in the Bongo District of Northern Ghana were analysed. Parasite density was determined by light microscopy and PCR, and parasite diversity was assessed by genotyping of the polymorphic Plasmodium falciparum msp2 block-3 region. Submicroscopic parasitaemia was estimated as the proportional difference between positive samples identified by PCR and microscopy. Dry season submicroscopic parasite prevalence was significantly higher (71.0%, p=0.013) at the dam site compared with the nondam site (49.2%). Similarly, wet season submicroscopic parasite prevalence was significantly higher at the dam site (54.5%, p=0.008) compared with the nondam site (33.0%). There was no difference in parasite density between sites in the dry season (p=0.90) and in the wet season (p=0.85). Multiplicity of infection (MOI) based on PCR data was significantly higher at the dam site compared with the nondam site during the dry season (p<0.0001) but similar between sites during the wet season. MOI at the nondam site was significantly higher in the wet season than in the dry season (2.49, 1.26, p<0.0001) but similar between seasons at the dam site. Multivariate analysis showed higher odds of carrying submicroscopic parasites at the dam site in both dry season (OR = 7.46, 95% CI = 3.07–18.15) and in wet season (OR = 1.73, 95% CI = 1.04–2.86). The study findings suggest that large water bodies impact year-round carriage of submicroscopic parasites and sustain Plasmodium transmission.

scholarly journals Initiation of gametocytogenesis at very low parasite density in Plasmodium falciparum infection

2017 ◽  
Vol 215 (7) ◽  
pp. 1167-1174 ◽  
Author(s):  
Ryan Farid ◽  
Matthew W. Dixon ◽  
Leann Tilley ◽  
James S McCarthy
Keyword(s):  
Plasmodium Falciparum ◽  
Parasite Density ◽  
Falciparum Infection ◽  
Plasmodium Falciparum Infection

scholarly journals Plasmodium falciparum gametocyte carriage in symptomatic patients shows significant association with genetically diverse infections, anaemia, and asexual stage density

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Paul Sondo ◽  
Biebo Bihoun ◽  
Marc Christian Tahita ◽  
Karim Derra ◽  
Toussaint Rouamba ◽  
...  
Keyword(s):  
Risk Factors ◽  
Plasmodium Falciparum ◽  
Body Temperature ◽  
Parasite Density ◽  
Genetic Variants ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Clinical Samples ◽  
Multiplicity Of Infection ◽  
Gametocyte Carriage

Abstract Background Multi-genotype malaria infections are frequent in endemic area, and people commonly harbour several genetically distinct Plasmodium falciparum variants. The influence of genetic multiplicity and whether some specific genetic variants are more or less likely to invest into gametocyte production is not clearly understood. This study explored host and parasite-related risk factors for gametocyte carriage, and the extent to which some specific P. falciparum genetic variants are associated with gametocyte carriage. Methods Gametocytes and asexual forms were detected by light microscopy on thick smears collected between 2010 and 2012 in Nanoro, Burkina Faso. Merozoite surface protein 1 and 2 were genotyped by nested PCR on clinical samples. Associations between gametocyte carriage and factors, including multiplicity of infection, parasite density, patient age, gender, haemoglobin (Hb) level, and body temperature were assessed. The relationship between the presence of a particular msp1 and msp2 genetic variants and gametocyte carriage was also explored. Results Of the 724 samples positive to P. falciparum and successfully genotyped, gametocytes were found in 48 samples (6.63%). There was no effect of patient gender, age and body temperature on gametocyte carriage. However, the probability of gametocyte carriage significantly increased with increasing values of multiplicity of infection (MOI). Furthermore, there was a negative association between parasite density and gametocyte carriage. MOI decreased with parasite density in gametocyte-negative patients, but increased in gametocyte carriers. The probability of gametocyte carriage decreased with Hb level. Finally, the genetic composition of the infection influenced gametocyte carriage. In particular, the presence of RO33 increased the odds of developing gametocytes by 2 while the other allelic families K1, MAD20, FC27, and 3D7 had no significant impact on the occurrence of gametocytes in infected patients. Conclusion This study provides insight into potential factors influencing gametocyte production in symptomatic patients. The findings contribute to enhance understanding of risk factors associated with gametocyte carriage in humans. Trial registration NCT01232530.

scholarly journals Age-dependent carriage of alleles and haplotypes of Plasmodium falciparum sera5, eba-175, and csp in a region of intense malaria transmission in Uganda

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Constance Agwang ◽  
Joseph Erume ◽  
Brenda Okech ◽  
Joseph Olobo ◽  
Thomas G. Egwang
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
Malaria Vaccine ◽  
Dried Blood Spots ◽  
P Value ◽  
Cross Sectional ◽  
Study Region ◽  
P Values ◽  
Vaccine Candidates ◽  
Age Dependent

Abstract Background The development of malaria vaccines is constrained by genetic polymorphisms exhibited by Plasmodium falciparum antigens. The project the age-dependent distribution of alleles or haplotypes of three P. falciparum malaria vaccine candidates, Circumsporozoite Protein (csp), Erythrocyte Binding Antigen 175 (eba-175) and Serine Repeat Antigen 5 (sera5) in a region of intense malaria transmission in Uganda. Methods A cross-sectional study was carried out between August and November 2009 in which 250 study participants were selected from a population of 600. Finger prick blood samples were collected after informed consent from participants below 5 years, 5–10 years, and above 10 years of age. Blood was used for microscopy, RDT and dried blood spots. Plasmodium falciparum DNA was extracted by chelex method. Alleles of sera5 and eba-175 were determined by polymerase chain reaction (PCR) amplification followed by resolution of products by agarose gel electrophoresis. Allele calling was done using gel photographs from ethiduim bromide stained gels. Haplotypes of csp were identified by sequencing 63 PCR products using the P. falciparum 7G8 laboratory strain sequence as a reference. The data were analysed using SPSS 16, EQX for windows and Chi-square test was used to calculate associations (P-values), Excel was used to generate graphs. The BioEdit and NCBI blast software programs were used to analyse the sequences from which csp haplotypes map was constructed. Results Eba-175 FCR3 (48/178) and CAMP (16/178) alleles were observed, the FCR3 (24/67) allele being predominant among children aged below 5 years old while the CAMP (12/67) allele was predominant among older participants. Sera5 alleles ORI (6/204) and ORII (103/204) were observed in the population, ORII was more prevalent and was significantly associated with age (P values < 0.0001), parasite density (P-value < 0.0001) and clinical outcomes (P value = 0.018). There was marked csp diversity in the Th2/Th3 region. Out of 63 sequences, 16 conformed to the reference strain and one (1/16) was similar to a West African haplotype and the majority (14/16) of the haplotypes were unique to this study region. There was an age-dependent distribution of csp haplotypes with more haplotypes being harbored by children < 5-year of age, (10/16) compared to adults (2/16). Interestingly, the csp haplotype corresponding to 3D7 whose prototypical sequence is identical to the sequence of the leading malaria vaccine candidate RTS, S was not observed. Conclusion This data suggest that the eba-175 FCR3 allele, sera5 ORII allele, and csp haplotypes are targets of host immunity and under immune selection pressure in Apac District. These molecules could provide alternative malaria vaccine candidates as sub-unit vaccines.

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