Seasonal Transmitting Potential of Malaria Vectors in Six Communities in Ekiti State, Nigeria

2021 ◽  
Vol 42 (1) ◽  
pp. 107-117
Author(s):  
O.F. Olorunniyi ◽  
O.A. Idowu ◽  
A.B. Idowu ◽  
O.R. Pitan ◽  
T.S. Oyeniyi ◽  
...  

Malaria vectors are found virtually in all communities of Nigeria. Understanding the transmitting potential of these vectors in  relationship with the malaria parasite (MP) infection is essential to design a sustainable community base control programme. This study aimed at determining this relationship in six communities in Ekiti State, Nigeria. The communities were randomly selected through a multistage sampling. Blood samples were screened for MPinfection among human volunteers during dry and rainy seasons in each community. Adult mosquitoes were collected indoors for twelve months in the communities using light traps. Female  Anopheles mosquitoes collected were characterized by Polymerase Chain Reactions and circumsporozoite proteins of the infected mosquitoes were detected by Enzyme-Linked Immunosorbent Assay. Prevalence of MP infection, human biting rates (HBR), sporozoite rates and entomological inoculation rates (EIRs) were determined using appropriate formulae. Overall prevalence of MPinfection was 26% in dry season and 38% in rainy season (P=0.001). Female Anopheles mosquitoes collected were 428. Strong relationship existed between HBR and MP infection in rainy  season (R2 = 0.671) but the relationship was weak (R2 = 0.209) in dry season. Sporozoites were detected in 2.3% of the female Anopheles mosquitoes collected. EIRs were between 0.100 - 0.252 infective bites/person/night.  Transmission of malaria parasites occurred throughout the year particularly during rainy season when there were recorded EIRs. Malaria control interventions will be more appropriate during raining season in this region. Keywords: Anophelesmosquitoes, Nigeria, transmission, malaria, season

2003 ◽  
Vol 66 (6) ◽  
pp. 1055-1062 ◽  
Author(s):  
GABRIELA NÁJERA-SÁNCHEZ ◽  
ROGELIO MALDONADO-RODRÍGUEZ ◽  
PATRICIA RUÍZ OLVERA ◽  
LYDIA MOTA de la GARZA

Two multiplex polymerase chain reactions were developed for the detection of enterotoxigenic strains of Staphylococcus aureus: one multiplex reaction for the simultaneous detection of enterotoxigenic strains type A (entA), type B (entB), and type E (entE) and another for the simultaneous detection of enterotoxigenic strains type C (entC) and type D (entD). Both reactions were standardized with the use of the reference enterotoxigenic strains of S. aureus: FRI 722, producer of staphylococcal enterotoxin (SE) type A (SEA); FRI 1007, producer of SEB; FRI 137, producer of SEC1; FRI 472, producer of SED; and FRI 326, producer of SEE. Optimized methods were used to determine the presence of enterotoxigenic types for 51 S. aureus strains isolated from meat (sausage, ham, and chorizo) and dairy (powdered milk and cheese) products by the Baird-Parker technique. The enterotoxigenic capacities of the strains were determined by the indirect enzyme-linked immunosorbent assay (ELISA) with the use of reference staphylococcal toxins and antitoxins. Fifty of the 51 strains isolated were enterotoxigenic and produced one to four enterotoxin types, with the most frequently produced types being SEA and SED. Levels of correlation between the presence of genes that code for the production of SE (as determined by polymerase chain reaction) and the expression of these genes (as determined by the indirect ELISA) were 100% for SEA and SEE, 86% for SEC, 89% for SED, and 47% for SEB.


2004 ◽  
Vol 87 (3) ◽  
pp. 639-646 ◽  
Author(s):  
Maricarmen Quirasco ◽  
Bernd Schoel ◽  
Javier Plasencia ◽  
John Fagan ◽  
Amanda Galvez

Abstract Alkaline-cooked corn, called nixtamal, is the basis for many traditional corn products such as tortillas, chips, and taco shells that are used widely in Mexico and Central America and in the preparation of snack foods that are consumed globally. To assess the effects of alkaline and thermal treatments on the detectability of DNA and protein for the presence of genetically modified sequences, various nixtamalized products were prepared from blends of conventional white corn containing 0.1, 1.0, and 10% transgenic corn (event CBH 351, StarLink™). Real-time quantitative polymerase chain reactions (RTQ–PCR) and immunoassays were used to determine the cry9C gene and protein, respectively, in unprocessed corn kernels, freshly prepared alkaline-cooked and ground corn (masa), masa flour, tortillas prepared from masa by heat treatment, chips prepared from damp masa dough by deep frying, and from tortillas processed at high (200°C) and low temperatures (70°C). In spite of progressive degradation of genomic DNA during processing, RTQ–PCR genetic analysis allowed detection and quantification of the cry9C gene in all products prepared from 10, 1, and 0.1% StarLink corn, except deep-fried chips containing 0.1% StarLink. Enzyme-linked immunosorbent assays readily detected <1ppm cry9C protein in all blends of unprocessed corn (10, 1, and 0.1% StarLink) as well as in nonfried tortilla and masa products. This technique was not suitable for thermally treated nixtamalized products containing <1% transgenic corn.


Author(s):  
Komang Iwan Suniada ◽  
Eko Susilo ◽  
Wingking Era Rintaka Siwi ◽  
Nuryani Widagti

The production of the Indonesian Institute for Marine Research and Observation’s mapping of forecast fishing areas (peta prakiraan daerah penangkapan ikan or PPDPI) based on passive satellite imagery is often constrained by high-cloud-cover issues, which lead to sub-optimal results. This study examines the use of the rolling mosaic method for providing geophysical variables, in particular, seasurface temperature (STT) together with minimum cloud cover, to enable clearer identification of oceanographic conditions. The analysis was carried out in contrasting seasons: dry season in July 2018 and rainy season in December 2018. In general, the rolling mosaic method is able to reduce cloud cover for sea-surface temperature (SST) data. A longer time range will increase the coverage percentage (CP) of SST data. In July, the CP of SST data increased significantly, from 15.3 % to 30.29% for the reference 1D mosaic and up to 84.19 % to 89.07% for the 14D mosaic. In contrast, the CP of SST data in December tended to be lower, from 4.93 % to 13.03% in the 1D mosaic to 41.48 % to 51.60% in the14D mosaic. However, the longer time range decreases the relationship between the reference SST data and rolling mosaic method data. A strong relationship lies between the 1D mosaic and 3D mosaics, with correlation coefficients of 0.984 for July and 0.945 for December. Furthermore, a longer time range will decrease root mean square error (RMSE) values. In July, RMSE decreased from 0.288°C (3D mosaic) to 0.471°C (14D mosaic). The RMSE value in December decreased from 0.387°C (3D mosaic) to 0.477°C (14D mosaic). Based on scoring analysis of CP, correlation coefficient and RMSE value, results indicate that the 7D mosaic method is useful for providing low-cloud-coverage SST data for PPDPI production in the dry season, while the 14D mosaic method is suitable for the rainy season.


Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 558-558 ◽  
Author(s):  
J. C. Noa-Carrazana ◽  
L. Silva-Rosales

Papaya mosaic virus (PMV) is a member of the Potexvirus group and has filamentous particles of 530 nm with a positive sense single-stranded RNA of 6.6Kb. PMV was detected in Mexico in diseased papaya plants growing alone and in mixed plantations with pumpkin. Reverse transcription polymerase chain reactions (RT-PCR) and standard double-antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) procedures were used on 45 leaf samples from single plants in seven locations in southeast Mexico (States of Yucatan, Campeche, and Quintana Roo). PCR primer design was based on a GenBank sequence with accession number D13957 (1). Amplified PCR products were cloned using a TOPO TA Cloning Kit and sequenced by the dideoxy chain termination method. Twenty-six samples tested positive for PMV using one or both detection techniques: 23 of 41 from papaya and three of four from pumpkin. The two sequences reported here, YY-15 and YY-22 (from papaya and pumpkin respectively, with accession numbers AYO17186 and AYO17187), were 1180 nucleotides long and contained a fragment of ORF3, the complete ORF4 and the putative CP gene, including the 3′ end untranslatable region. Within the CP gene sequence, the amino acid sequence derived had a similarity of 88% with that of D13957 from the GenBank. The similarity of the CP between the two Mexican isolates (from papaya and pumpkin) was 94% and would therefore represent two variants of PMV. A healthy papaya plant in the greenhouse, inoculated with tissue from an infected papaya plant from the field, tested positive for PMV in DAS-ELISA. (PVX was used as a negative control). These results confirmed the identity of the isolate as PMV. Reference: (1) T. L. Sit, M. G. AbouHaidar, and S. Holi. J. Gen. Virol. 70:2335-2331, 1989.


Plant Disease ◽  
1999 ◽  
Vol 83 (1) ◽  
pp. 77-77 ◽  
Author(s):  
N. P. Henríquez ◽  
L. Kenyon ◽  
L. Quiroz

Successive plantings of sweet corn in Orange Walk District, Belize (<200 m ASL) were observed to be performing poorly. Plants were stunted with shortened upper internodes, over-production (proliferation) of ears, and chlorosis of ears and leaf bases. Plants of hybrid white corn in Cayo District (<200 m ASL) had leaf-base chlorosis, mid-vein reddening, chlorotic bands on the leaves, and die-back of leaf tips: symptoms attributed to infection by the corn stunt complex (CSC) pathogens. Spiroplasma kunkelii was detected in symptom-bearing leaf-base samples of white corn but not sweet corn, using a specific F(ab')2 protein-A enzyme-linked immunosorbent assay (ELISA; D. Gordon, Ohio). Polymerase chain reactions with maize bushy stunt (MBS) phytoplasma-specific primers (1) resulted in amplification products of the expected size (740 bp) when DNA extracts from either sample type were used as template. DNAs from apparently healthy sweet or white corn from the field, or from glasshouse-grown sweet corn, did not yield this product. MBS and S. kunkelii are transmitted by leafhoppers of the genus Dalbulus, often simultaneously with maize rayado fino virus, the other CSC component (not tested for in this study). All the sweet corn varieties examined had a high incidence of the symptoms, suggesting that they are highly susceptible to one or both of the CSC mollicutes. With the increase in area dedicated to maize production and successive year-round plantings, the potential for spread and increased incidence of MBS or CSC in Belize is considerable. Reference: (1) N. A. Harrison et al. Plant Dis. 80:263, 1996.


2017 ◽  
Author(s):  
Tjahyo Nugroho Adji

This research was conducted within Bribin underground river, the primary river in the Gunung Sewu karst area, Gunung Kidul, Java, Indonesia. The main purpose of this study is to describe hydrogeochemical processes that occur at the upstream of Bribin River. In addition, this study also differentiates hydrogeochemical dominant processes, which come about in rainy season and dry season. Study area boundary is the upper rainfall catchment of Bribin River that is focused on three locations: Pentung River (surface), Luweng Jomblangan, and Gilap Cave. Discharge measurements for one yearperiod are conducted to define discharge hydrograph. Furthermore, baseflow separation analysis is conducted to determine the percentage of base flow (PAD) throughout the year. Water sampling for hydrogeochemical analysis is taken everymonth to represent dry season and rainy season condition. To describe the hydrogeochemical processes, scatter plot analysis with small sample size is conducted. The result shows that within dry season, dominant hydrogeochemical process is water rock interaction that indicates by: achieving maximum level of Ca2+-HCO3- ; strong relationship between discharge increment and PAD reduction; strong relationship between increasing of Ca2+-HCO3- and increasing of PAD. In addition,strong relationship between the increase in Ca2+-HCO3- and reduction of carbondioxide in water as well as minimum level of carbondioxide gas in water at the peak of dry season, is also present. In rainy season, hydrogeochemical process shifted from water-rock interaction to dilution by precipitation as a result of rain water supply through conduit system channel,which is characterized by: declining in Ca2+-HCO3- when discharge increase; increasing Ca2+-HCO3- when discharge decrease; low correlation of spesific conductivity vs Ca2+-HCO3 -; low correlation of PAD vs Ca2+-HCO3 - when discharge increase, strong correlation between declining in PAD by increasing of CO2 in the water, and rising of CO2 when discharge increase.


2013 ◽  
Vol 25 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Gallo Sow ◽  
Karamoko Diarra ◽  
Laurence Arvanitakis ◽  
Dominique Bordat

ABSTRACT The impact of abiotic and biotic factors (rainfall, temperature, host plant and natural enemies) on population dynamics of the Plutella xylostella L. diamondback moth was investigated. The experiments were conducted during the rainy and dry seasons for two years (June 2009-April 2011) on unsprayed cabbage plots in Malika (Senegal). Every 10 days, 10 cabbages were randomly selected. Plutella xylostella larvae, pupae and parasitoid cocoons were recorded on each plant. Before each sampling, the diameters and ages of plants were recorded. Temperature and rainfall were also recorded during this study. Larvae and pupae of P. xylstella were higher for the dry season than the rainy season. There was a negative correlation between temperature and P. xylostella populations, and a strong relationship between P. xylostella populations and the age of cabbages. Females oviposited on young cabbages where the presence of young larvae was important, whereas older immature stages were mainly found in older cabbage plants. Parasitoid populations were higher for the dry season than the rainy season. High temperatures did not increase the pest populations and parasitism rate. There was no effect found on pest, plants and natural enemies due to rainfall. There was a positive correlation between pest populations and parasitism. Four Hymenoptera species were found: Oomyzus sokolowskii, Apanteles litae, Cotesia plutellae and Brachymeria citrae, but they were not efficient to control the P. xylostella populations. These results are important for understanding the factors that promote or inhibit pest populations and their natural enemies, and therefore essential for effective crop protection.


Author(s):  
Omojola F. Olorunniyi

Understanding the relationship between climate variables and mosquito abundance is an important factor to determine parasite activity levels and disease risk since various mosquito genera are vectors of parasitic diseases. This necessitated the investigation of relationship between climatic variables and mosquito abundance in Ekiti State, Nigeria with reference to six selected communities. Adult mosquitoes were collected indoor for twelve months in these communities using light traps. The abundance of collected mosquitoes was related with climatic variables (rainfall, relative humidity and temperature). One thousand two hundred and seventeen (1217) adult mosquitoes were collected indoor in all the communities. The population of the mosquito genera was significantly higher (P=0.01) in rainy season than dry season. Average rainfall showed a strong relationship (R2= 0.751) with Anopheles abundance but relationship was weak for both Culex (R2= 0.236) and Aedes (R2= 0.042). The relationship of relative humidity and average temperature with abundance of mosquito genera was generally weak. Since the abundance of mosquito genera was higher in all the communities during rainy season than dry season it will be more appropriate to control mosquitoes in the communities during the rainy season.


Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1802
Author(s):  
Pimolpachr Sriburin ◽  
Pichamon Sittikul ◽  
Nathamon Kosoltanapiwat ◽  
Salin Sirinam ◽  
Watcharee Arunsodsai ◽  
...  

Zika virus (ZIKV) is the mosquito-transmitted virus that the WHO declared a Public Health Emergency of International Concern in 2016 due to the consequence of microcephaly from infected pregnancies. The incidence of Zika infection has been unclear in many countries because most infected people have nonspecific febrile illnesses. This study’s aim is to investigate the incidence of symptomatic Zika virus infections from the archived samples of a dengue cohort study of children in central Thailand from 2006 to 2009. We performed Zika NS1 immunoglobulin (Ig)G enzyme-linked immunosorbent assay (ELISA) screening to identify symptomatic Zika infections in paired acute/convalescent serum samples. Symptomatic Zika infections were confirmed by reverse transcription polymerase chain reactions (RT-PCR) of acute serum samples. The comparison of the Zika NS1 IgG ELISA results between acute and convalescent samples showed 290/955 (30.4%) seropositive cases. Zika RT-PCR results were positive in 28 febrile cases (15 females, 13 males). Zika RT-PCR showed that symptomatic Zika infection occurred in children aged 4–11 years in Ratchaburi province, Thailand (2007–2009, first case in April 2007), and the symptomatic Zika:dengue infection ratio was 28 Zika:394 dengue (1:14). Phylogenetic analysis showed that all Zika viruses were of Asian lineage. Zika NS1 IgG ELISA identified Zika-infected patients and showed a low Zika:dengue ratio.


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