Blood Films For Parasites Research Articles

Point prevalence mapping of malaria infection in Rivers State, Nigeria

Background: Variations in the risk of malaria across locations exist but are poorly understood though identifying hotspots of malaria transmission will create opportunities for targeted interventions. Point prevalence of malaria in Rivers State was studied using Primary Healthcare Centres (PHCs) as survey points.
 Methods: The PHCs in Rivers State were geo-referenced using a handheld Global Positioning System (GPS) and 74 were selected across 21 local government areas using systematic grid point sampling. Blood samples were obtained from 2340 persons who consented and questionnaires were administered to obtain their demographic data. Malaria parasites in blood films were detected using the Giemsa staining technique. Data generated were analysed using SPSS 22.0 and presented using descriptive statistics. The level of relationship amongst the parameters was obtained using Chi-square. Co-ordinates of PHCs sampled and their prevalence data for malaria were entered into Microsoft Excel 2007 spreadsheet and transmitted to ArcGIS 10.8. This platform was then used to produce point prevalence infection maps of the State using geographic information systems (GIS). Survey points with malaria point prevalence values of 75% and above and cumulative prevalence of 1.97% and above were categorised as malaria transmission hot spots in the various LGAs.
 Results: The study recorded an overall prevalence of 56.3%, with P.falciparum as the only identified malaria parasite. Data revealed that Oyoro Model Primary Health Centre (MPHC), Arukwo Primary Health Centre, Ele Health Post (HP) and Emago HP recorded very high prevalence of 96.7%, 96%, 95.2% and 94.4% respectively, whereas MPHC Iriebe had the least prevalence. Twelve hotspots with point prevalence above 75% were identified and eight hotspots likewise with cumulative prevalence above 1.97%.
 Conclusion: Malaria infection remains endemic in Rivers State. This study provides malaria point prevalence maps of Rivers State which will serve as a reference to policymakers for strategic interventions in the State

Trypanosoma brucei rhodesiense infection in a Chinese traveler returning from the Serengeti National Park in Tanzania

BackgroundHuman African trypanosomiasis (HAT) is one of the most complex parasitic diseases known to humankind. It usually occurs in endemic areas in Africa, but is occasionally detected in returning travelers and migrants in non-endemic countries.Case presentationIn August 2017, a case of HAT was diagnosed in China in a traveler returning from the Masai Mara area in Kenya and the Serengeti area in Tanzania. The traveler visited Africa from 23 July to 5 August, 2017. Upon return to China, she developed a fever (on 8 August), and Trypanosoma brucei rhodesiense infection was confirmed by laboratory tests (on 14 August) including observation of parasites in blood films and by polymerase chain reaction. She was treated with pentamidine followed by suramin, and recovered 1 month later.ConclusionsThis is the first imported rhodesiense HAT case reported in China. This case alerts clinical and public health workers to be aware of HAT in travelers, and expatriates and migrants who have visited at-risk areas in Africa.

Do the venous blood samples replicate malaria parasite densities found in capillary blood? A field study performed in naturally-infected asymptomatic children in Cameroon

BackgroundThe measure of new drug- or vaccine-based approaches for malaria control is based on direct membrane feeding assays (DMFAs) where gametocyte-infected blood samples are offered to mosquitoes through an artificial feeder system. Gametocyte donors are identified by the microscopic detection and quantification of malaria blood stages on blood films prepared using either capillary or venous blood. However, parasites are known to sequester in the microvasculature and this phenomenon may alter accurate detection of parasites in blood films. The blood source may then impact the success of mosquito feeding experiments and investigations are needed for the implementation of DMFAs under natural conditions.MethodsThick blood smears were prepared from blood obtained from asymptomatic children attending primary schools in the vicinity of Mfou (Cameroon) over four transmission seasons. Parasite densities were determined microscopically from capillary and venous blood for 137 naturally-infected gametocyte carriers. The effect of the blood source on gametocyte and asexual stage densities was then assessed by fitting cumulative link mixed models (CLMM). DMFAs were performed to compare the infectiousness of gametocytes from the different blood sources to mosquitoes.ResultsPrevalence of Plasmodium falciparum asexual stages among asymptomatic children aged from 4 to 15 years was 51.8% (2116/4087). The overall prevalence of P. falciparum gametocyte carriage was 8.9% and varied from one school to another. No difference in the density of gametocyte and asexual stages was found between capillary and venous blood. Attempts to perform DMFAs with capillary blood failed.ConclusionsPlasmodium falciparum malaria parasite densities do not differ between capillary and venous blood in asymptomatic subjects for both gametocyte and trophozoite stages. This finding suggests that the blood source should not interfere with transmission efficiency in DMFAs.

A Novel Real Time PCR Assay for the Detection of Babesia microti in a Highly Endemic Area Using Luminex Aries System

BackgroundBabesiosis is a tick-borne infection of erythrocytes caused by parasites of the genus Babesia. In United States most of the reported cases occur in the Northeast and upper Midwestern states, New York being an endemic area. Majority of the cases in the United States is due to infection with Babesia microti. Most patients with babesiosis are asymptomatic or have a mild illness, but some may develop fatal illness. Current laboratory diagnosis of Babesiosis including parasitemia is by microscopic demonstration of intraerythrocytic Babesia parasites in blood films which requires specially trained personnel. We have developed a simple and rapid PCR assay for the detection of B. microti 18S rRNA gene (BMPCR) which can be used as an alternative screening assay.MethodsBMPCR assay was developed based on Luminex Multicode technology using Luminex Aries instrument and in-house developed primers. Babesia positive clinical samples confirmed by NY State Department of Health and clinical samples negative for Babesia were used to determine accuracy. Specificity was evaluated using malaria positive samples, several bacterial isolates, selected B. microti strains and other Babesia species. Limit of Detection was determined using known copies of B. microti DNA. Reproducibility of the assay was assessed by testing samples on different days and runs by different analysts.ResultsAccuracy of the BMPCR assay was 100% for the 30 Babesia positive and 30 negative samples. All B. microti ATCC strains were positive by BMPCR. 95% LOD of the assay as determined by probit analysis was 1177 copies/50µl of blood. Sensitivity of the assay was higher than that of microscopic detection and specificity was 100%. No cross reactivity was observed with any of the malarial species tested. Babesia MO1, Babesia duncani and all bacterial isolates tested were negative by the BMPCR. Intra-run, inter-run and day to day reproducibility of the assay was 100%.ConclusionThe B. microti real time PCR assay developed by Northwell Health Laboratories is rapid, sensitive, specific and reproducible. With the sample to result turnaround time of 2.5 hours and hands on time of only 5 minutes per sample, BMPCR can be used as screening assay for B. microti in clinical laboratories.Disclosures All authors: No reported disclosures.

External quality assessment in the examination of blood films for malarial parasites within Ontario, Canada.

To assess laboratory practice in the examination of blood films for malarial parasites. Ontario medical laboratories, licensed by the Ministry of Health, are required to participate in external quality assessment by the Laboratory Proficiency Testing Program, which assesses performance of laboratory assays and also examines the total testing process. Educational strategies are used to improve performance. A 1995 survey indicated shortcomings in detection and identification of malarial parasites in blood films. Consequently, recommendations for the investigation of malarial parasites in blood were issued. In 1996 and 1997, 16 workshops were conducted. A 1997 follow-up external quality assessment survey indicated that problems persist as 27% of laboratories failed to correctly speciate Plasmodium falciparum. Good Practice Guidelines were issued in 1998. Further education and assessment are required. Laboratories lacking expertise must establish referral arrangements with more proficient laboratories.

Rapid diagnosis of malaria by fluorescence microscopy with light microscope and interference filter

Fluorochrome staining to detect malaria parasites in bloodfilms is more sensitive, is easier to do, and is less time-consuming than Giemsa staining. However, standard epi-illuminated, mercury vapour, fluorescence microscopes are expensive, especially for tropical countries where malaria is endemic. Fluorescence microscopy with a standard light microscope and a new interference filter specially designed for the fluorochrome stain, acridine orange, was used to detect malaria parasites in thick and thin bloodfilms. In this system two fluorescence colours, green (nuclei) and red (cytoplasm), were emitted from stained parasites. Thick and thin bloodfilms from patients with malaria were examined with this system. Bloodfilms had been fixed and stored for 1-5 years. Rapid scanning of both thick and thin bloodfilms was possible at a magnification of × 200 with standard lenses, indicating that this may be a useful economic system for rapid diagnosis of malarias.

Medicine among Nilotics in the Sud.

So you are going to Ler. Well, I wish you luck. I don't know how the doctor stands it out there. It's the fly capital of the world, the pilot remarked cheerfully to me as we took off in a small single-engine plane. He was taking me, together with the fortnightly supply of food, drugs, and mail, to the American couple living there. Ler was the last stop on a long journey over _ miles of crocodile L-t,-^ AroST?8^^5^ i infested swampland in I HT m*0,Wrm' o?? tne southern Sudan: an edira?^uy *? area known as the Sud ( yV:?(fig !)? I* is extremely EGYPT ^?, SAUW flat inhospitable country, /? j ^S A**fflA ?4 totally cut off by floods *rL?miUM ?'?*? f during tbe rains, while ? _ .^g'^^y-i^^^^L^^. A during the dry season y-'-V^?%:':'v^g^ the receding swamps I ?Jfc : : ? m'W:-:'-'^?\Wtt A become a semidesert. I '*>?:?: :^!v??^^:;::^#? *^^a I Ap911 ^rom tne ^ort \'.-V%V.1?-;???^?iJ^F.->' ? Sfe I ^ghtly Pi3116 service the I ?:???!'? ? ?-' #T V C*^ I on^y otner regular means L^^r^^ of communication with T ^^/;:^ [ the outside world was r1 v;r _ ^fcfe^-^'y-^k' ?'? '?' v*.1 ^y private radio. p*-* '^^^?fc??lS^ The southern Sudan T ?-* K^ > I suffered some 17 years : A ^y K^*-J ?:i?l ?f dvil war during the Zaire , Py^N? -?apsEl I 1960s ^d '70sThis 1 i--? IvSsT'^^^Pl: resulted in all external Y%*N?^ ^ be?lg dliven OUt L ' V * Cq^yl [ and schools and hospi |_^ /^S^ V cl?!P^ ta^s Deing destroyed, so ^ '-^^?* the people lived without medical services for years. I chose this area for my elective because the people of the Upper Nile, the Dinka and Nuer tribes, are extremely isolated and have preserved their culture intact. I also expected to find some very primitive and basic medicine; the reality proved to be more than I imagined. There was no running water or electricity in either the house or the hospital, and everywhere there were broken windows and handleless doors. Two wells served the whole area and frequently ran dry. Paradoxically in the middle of a swamp the greatest problem was water. On arrival I was carefully warned that my room was known as the scorpion room, but I was told not to worry since there were far worse things than a few scorpions in the southern Sudan. I shall never forget my first visit to the hospital. I expected dirt but was not prepared for what I saw. Through lack of water everything was filthy: the walls, the patients, the beds, and the mattresses were all covered with a multitude of flies. Ler is a government hospital, but the doctor working there is employed by a missionary organisation and thus does not have the control or support necessary to maintain the standards that she would wish. Of 20 nurses on the payroll, only two were working. As a result I did nursing and laboratory duties as well as those of a doctor. In addition to becoming adept at the ancient art of drawing water from the well and kindling charcoal fires, I also learned how to do a third-world cross-match for transfusions and to recognise parasites such as amoeba, strongyloides, and schistosomes in stools and malarial parasites in blood films.

Distribution of Simian Malaria Parasites in Various Hosts

On the basis of periodicity and morphology the simian malaria parasites are considered to fall into six distinct groups. In line with the evolution of these parasites each is briefly considered with reference to a diagramatic primate tree, and to a corresponding diagram, showing the degrees of susceptibility of these primates to the parasites of malaria. The term "malaria parasites" is applied either in a narrow sense to species of Plasmodium sensu stricto or to all pigmented parasites of erythrocytes. In the former the parasite is defined as undergoing two types of schizogony in the vertebrate host: the first in tissue cells and the second, accompanied by gametogony, in the blood with the production of "malaria pigment," while sporogony occurs in an insect, usually a mosquito. In the wider sense, haemoproteids are also included under the name of "malaria parasites," and these are defined as parasites which undergo schizogony in the tissues, but not in the blood where (pigmented) gametogony alone occurs, and which undergo sporogony in an insect other than a mosquito. Some authorities still retain mammalian parasites of the latter type in the genus Plasmodium, e.g., P. kochi or P. brodeni, while the presence of pigmented parasites in blood films of wild animals inevitably raises the question as to whether they are true Plasmodium or belong to the Haemoproteidae, and it is frequently difficult to be certain of the diagnosis, particularly in mixed infections. The organisms are therefore often referred to as "malaria parasites," and it is for these reasons that I propose in the present paper to include the two genera, Plasmodium and Hepatocystis, Received for publication 8 October 1963. * Presented at the XVI International Congress of Zoology, Washington, D. C., on 21 August 1963 and sponsored by the American Society of Parasitologists and the British Society of Parasitology. in my survey. Moreover, their respective species must have a close phylogenetic relationship and it is useful to consider them together. Having defined "malaria parasites," the next question is the delimitation of the word "simian." The term simian, in contrast to primate malaria, excludes man at the top and the tarsioids, lemuroids, etc., at the bottom of the scale, and parasitologically such a separation is convenient because, on the one hand, the malaria parasites of lemurs are highly specialized and appear to belong to the rather heterogeneous group found in small mammals, while on the other, the human parasites again exhibit distinctive features-they are limited, for instance, to species within the genus Plasmodium. Hepatocystis is thus absent in man and also in the higher apes (chimpanzee and gorilla) which have parasites almost indistinguishable from the human ones, including the most highly evolved species in the subgenus Laverania. There is evidence today that the chimpanzee and gorilla are closer to man than the other so-called higher apes-the orangutan and still more the gibbon-and for this reason the present survey will omit the chimpanzee and gorilla from detailed consideration while including those of the gibbon and orangutan. For tracing the phylogeny, however, both lemuroid and human parasites must be included. The distribution of species of simian malaria parasites could be discussed in at least two ways: (1) the distribution of similar types of

Blood examination and prognosis in acute falciparum malaria

In a series of 2,316 cases of acute uncomplicated falciparum malaria, there were 50 deaths. Parasites in blood films were counted in all cases daily during treatment. Analysis of this material shows a close relation between the death-rate and the peripheral concentration of parasites at the time treatment began. Parasite counts made at this time were more reliable than clinical judgment as a guide to prognosis, and their routine adoption in all serious falciparum infections is recommended. With few exceptions the presence of falciparum schizonts in blood films at the lower levels of parasitaemia was not a reliable indication of clinical gravity. The vexed question of blood-negative pernicious malaria is briefly discussed. Evidence on the limiting intensity of non-fatal falciparum infection is given.