Diagnosis of Malaria Infection Using Non Radioactive Malaria Diagnostic System (NOMADS)

Background

Malaria remains one of the leading causes of morbidity and mortality. A definitive and early diagnosis remains the biggest challenge world-wide. Light microscopy of blood smears has been the gold standard in diagnosis of malaria for decades. This routine microscopic diagnosis is often unreliable and may not be available at many peripheral health centers. Hence newer diagnostic techniques have been developed based on antigen detection.

Method

Microscopy and Non-radioactive Malaria Detection System (NOMADS) to diagnose falciparum malaria were compared. Specificity and sensitivity of this technique and applicability of the kit for rapid and reliable malaria diagnosis were evaluated. 2579 samples of blood were processed. Both thick and thin blood smear examination and NOMADS was carried out on each of them. All smear positive samples and highly suspicious clinical cases were also subjected to detection of HRP-2 antigen by ICT Malaria Pf test.

Results

The detection rate for malaria on smear examination (both vivax and falciparum) was highest at Dimapur (7.41%), followed by Tezpur (7.13%), Kolkata (7%), Guwahati (6%) and Changsari (3.6%). All centers had greater incidence of falciparum compared to vivax except Kolkata where only vivax was detected. The sensitivity of NOMADS was 0%, 4.8%, 13.5%, 42.9% and 52.8% at Kolkata, Tezpur, Guwahati, Changsari and Dimapur respectively. The specificity of the test ranged between 91.8% at Changsari to 95.9% at Dimapur. The specificity at Tezpur, Kolkata and Guwahati was 92.3%, 94% and 95.3% respectively.

Conclusion

The study revealed that the test kit developed needs to be standardised as regards calculation of cut off values for each of the test runs and reproductibility of optical density readings. Immuno-Chromatography Test (ICT) is helpful in early diagnosis, management and follow-up of cases of malignant malaria.Key Words: Falciparum malaria, Immuno-Chromatography Test (ICT), NOMADS     

Prevalence of malaria infection in Sarbaz,Sistan and Bluchistan province

Objective

To survey malaria prevalence in Sarbaz from April 2009 to October 2010.

Methods

Epidemiological data of 1 464 confirmed malarial patients were analyzed according to demographic status, sex, age, nationality, isolated species and residence place.

Results

The majority of patients were male 950 (64.8%) but 514 (35.2%) were female. 82.5% of patients were Iranian, 14% Pakistani immigrants, and 3.5% Afghan immigrants. Data collected showed that 90% of isolated species were Plasmodium vivax, 7.8% Plasmodium falciparum, and 2.2% Plasmodium malariae and mixed species.

Conclusions

Therefore, it is crystal clear that refugees should be prohibited by government and controlled by experts in health centers in order to campaign effectively with this life threating disease.     

Synthesis of silver nanoparticles using leaves of Catharanthus roseus Linn. G. Don and their antiplasmodial activities

Objective

To develop a novel approach for the green synthesis of silver nanoparticles using aqueous leaves extracts of Catharanthus roseus (C. roseus) Linn. G. Don which has been proven active against malaria parasite Plasmodium falciparum (P. falciparum).

Methods

Characterizations were determined by using ultraviolet-visible (UV-Vis) spectrophotometry, scanning electron microscopy (SEM), energy dispersive X-ray and X-ray diffraction.

Results

SEM showed the formation of silver nanoparticles with an average size of 35–55 nm. X-ray diffraction analysis showed that the particles were crystalline in nature with face centred cubic structure of the bulk silver with the broad peaks at 32.4, 46.4 and 28.0.

Conclusions

It can be concluded that the leaves of C. roseus can be good source for synthesis of silver nanoparticle which shows antiplasmodial activity against P. falciparum. The important outcome of the study will be the development of value added products from medicinal plants C. roseus for biomedical and nanotechnology based industries.     

Use of buffy coat thick films in detecting malaria parasites in patients with negative conventional thick films

Objective

To determine the frequency of malaria parasite detection from the buffy coat blood films by using capillary tube in falciparum malaria patients with negative conventional thick films.

Methods

Thirty six uncomplicated falciparum malaria patients confirmed by conventional thick and thin films were included in the study. The patients were treated with artemisinin combination therapy at Hospital for Tropical Diseases, Bangkok, Thailand for 28 day. Fingerpricks for conventional blood films were conducted every 6 hours until negative parasitemia, then daily fingerpricks for parasite checks were conducted until the patients were discharged from hospital. Blood samples were also concurrently collected in 3 heparinized capillary tubes at the same time of fingerpricks for conventional blood films when the prior parasitemia was negative on thin films and parasitemia was lower than 50 parasites/200 white blood cells by thick film. The first negative conventional thick films were compared with buffy coat thick films for parasite identification.

Results

Out of 36 patients with thick films showing negative for asexual forms of parasites, buffy coat films could detect remaining 10 patients (27.8%) with asexual forms of Plasmodium falciparum.

Conclusions

The study shows that buffy coat thick films are useful and can detect malarial parasites in 27.8% of patients whose conventional thick films show negative parasitemia.     

Autopsy study of febrile deaths during monsoon at a tertiary care institute in India: Is malaria still a challenge?

Background:

To utilise an autopsy-based approach to study the febrile deaths and deaths due to malaria during monsoon period of three years at a tertiary care teaching hospital in Mumbai, India.

Materials and Methods:

All autopsies done at the hospital during monsoon period from 2005 to 2007 when fever was the main presenting symptom were included in the study. Monsoon period was defined from June to September. A study on the duration of hospital stay of malaria deaths was also attempted.

Results:

There were 202 autopsies of febrile illness during the study period. Malaria resulted in 20.8% of the deaths besides other causes. A majority of deaths had intrapulmonary haemorrhages as the only pathological finding. Incidence of malaria deaths was more during monsoon period than the non-monsoon period. Plasmodium falciparum was the most common species responsible for malaria deaths while cerebral malaria was the most common mode of death. In 27% of the cases, post-mortem examination helped to arrive at the correct final diagnosis. In 88.1% of the cases, malaria deaths occurred within the first 24 hours of admission to the hospital.

Conclusion:

The study reiterates the fact that malaria remains a preventable but major cause of death in India, predominantly during the monsoon period. The study also emphasises the importance of developing treatment protocols for malaria during such crucial times besides reinforcing the existing preventive measures.     

Association of ABO blood group and Plasmodium falciparum malaria in Dore Bafeno Area,Southern Ethiopia

Objective

To assess the distribution of ABO blood group and their relationship with Plasmodium falciparum (P. falciparum) malaria among febrile outpatients who sought medical attention at Dore Bafeno Health Center, Southern Ethiopia.

Methods

A total of 269 febrile outpatients who visited Dore Bafeno Health Center, Southern Ethiopia, were examined for malaria and also tested for ABO blood groups in January 2010. The blood specimens were collected by finger pricking, stained with Geimsa, and examined microscopically. Positive cases of the parasitemia were counted. CareStart™ Malaria Pf/Pv Combo was also used to test the blood specimens for malaria. ABO blood groups were determined by agglutination test using ERYCLONE^® antisera. Data on socio-demographic characteristics and treatment status of the participants were also collected. Chi-square and ANOVA tests were used to assess the difference between frequencies and means, respectively.

Results

Out of a total of 269 participants, 178 (66.2%) febrile patients were found to be infected with Plasmodium parasites, among which 146 (54.3%), 28 (10.4%), and 4 (1.5%) belonged to P. falciparum, P. vivax, and mixed infections, respectively. All febrile patients were also tested for ABO blood groups and 51.3%, 23.5%, 21.9% and 3.3% were found to be blood types of O, A, B and AB, respectively. Both total malaria infection and P. falciparum infection showed significant association with blood types (P<0.05). The proportion of A or B but not O phenotypes was higher (P<0.05) in individuals with P. falciparum as compared with non-infected individuals. The chance of having P. falciparum infection in patients with blood groups A, B and AB was 2.5, 2.5 and 3.3 times more than individuals showing blood O phenotypes, respectively. The mean P. falciparum malaria parasitaemia for blood groups A, B, AB, and O were 3 744/µL, 1 805/µL, 5 331/µL, and 1 515/µL, respectively (P<0.01).

Conclusions

The present findings indicate that individuals of blood groups A, B and AB are more susceptible to P. falciparum infection as compared with individuals of blood group O. Nevertheless, further in depth studies are required to clearly establish the role that ABO blood group plays in P. falciparum malaria.     

Molecular investigation of mixed malaria infections in Southwest Saudi Arabia

Objective:

To investigate the incidence of mixed-species (MS) malaria infection, and compare the results with microscopically confirmed cases of malaria.

Methods:

During 2010, blood spots collected from 371 clinically suspected cases of malaria were microscopically examined in a cross-sectional study. The DNA was extracted from the samples, and a nested polymerase chain reaction (PCR) was performed. The results obtained by the 2 methods were compared.

Results:

From the microscopic analysis it was determined that 369 samples (99.5%) were positive for Plasmodium falciparum (P. falciparum) and 2 were Plasmodium vivax (P. vivax) mono-infections. There were no mixed malaria infections. The PCR analysis, however, showed that in 7 cases (1.9%) the infection was caused by MS malaria comprising of P. falciparum and P. vivax, 2 of these representing the cases that were microscopically diagnosed as P. vivax mono-infections. All cases were negative for Plasmodium malariae, Plasmodium ovale, and Plasmodium knowlesi.

Conclusion:

Mixed malaria infections are currently overlooked when using microscopy. The PCR assays are essential complementary techniques that should be used with microscopic examination of blood smears.Malaria is among the most prevalent of endemic tropical diseases. Human infection with malaria is caused by 4 species of plasmodia: Plasmodium falciparum (P. falciparum), Plasmodium vivax (P. vivax), Plasmodium malariae (P. malariae), Plasmodium ovale (P. ovale), and, rarely, Plasmodium knowlesi (P. knowlesi). Each of these species is associated with different clinical features and outcomes. The risk of severe malaria symptoms increases considerably if treatment is delayed. In 2012, 99 countries documented ongoing malaria transmission with around 3.3 billion people at risk of contracting the disease. Globally, 219 million cases of malaria were reported with 660,000 associated deaths.1 In Africa, the predominant malaria species is P. falciparum. Elsewhere; however, including Russia, the tropical regions of Asia, the Pacific, and South, and Central America, P. vivax is the most common species. In geographical areas where more than one malaria species is present, these infections may combine and such combined infections are usually under-reported.2 In the Kingdom of Saudi Arabia (KSA), Jazan and Aseer provinces, in the south-west of the country, are the most malaria-endemic areas with a prominence of P. falciparum. No mixed-infection cases have been reported from these regions.3 In early 2008, Artemisinin-based combination therapy (ACT) was introduced to KSA to treat all malaria-positive cases. For P. vivax malaria, chloroquine is used, but when P. vivax is resistant to chloroquine, an appropriate ACT regimen is recommended together with a primaquine regimen.4 Severe and complicated malaria is most commonly caused by P. falciparum, although P. vivax, and P. knowlesi may also be responsible for severe infections. Research on the P. vivax parasite has tended to lag behind, since it was previously thought that mono-infection with P. vivax resulted only in benign tertian fever, and that severe cases of P. vivax infection were the result of co-infection with P. falciparum. Recent evidence, however, suggests that clinical symptoms for this infection have changed and that P. vivax mono-infections can result in severe malaria (SM) and even death.5 Incorrect diagnosis of the malaria species causing infection in a patient is a potentially significant problem, since misdiagnosis could result in the infection becoming severe, in the case of P. falciparum, or relapse in the case of P. vivax.6 False-negative diagnoses for P. vivax are common in endemic areas, and many untreated patients therefore serve as reservoir hosts of malaria parasites.7 In addition, if P. vivax schizonts are detected in venous blood, co-infection with P. falciparum may be missed, since P. falciparum schizonts are only present in the capillaries of internal organs.7Microscopic examination of Giemsa-stained blood films is the best technique for detecting the malaria parasite due to its low cost and ability to distinguish between malaria species. Nevertheless, accurate diagnosis depends on an experienced technician. Misdiagnosis can easily occur, particularly in cases involving mixed malarial infections or when parasitemia is low.8 To overcome these limitations, several diagnostic methods have been developed, including rapid diagnostic tests (RDT), serologic tests and direct polymerase chain reaction (PCR).8 Overall microscopy and RDTs comprise the main means of diagnosing the presence of malaria. When it is necessary to distinguish between the infecting species, PCR would be preferred. Of these approaches, PCR assays are most commonly used to detect the 5 species of plasmodia precisely. The PCR techniques involve a universal plasmodium primer based on the sequence of the small-subunit ribosomal RNA (ssrRNA) gene.9The purpose of this study was to explore the prevalence of mixed-species infections of P. falciparum and P. vivax parasites as well as P. malariae, P. ovale, and P. knowlesi in Jazan Province - south-west Saudi Arabia by PCR and compare the results obtained with microscopically confirmed cases of malaria.     

Uncomplicated malaria in children: The place of rapid diagnostic test

Background:

Malaria has remained a major cause of morbidity and mortality among the under-five children in Nigeria. Prompt and accurate diagnosis of malaria is necessary in controlling this high burden and preventing unnecessary use of anti-malarial drugs. Malaria rapid diagnostic test (MRDT) offers the hope of achieving this goal. However, the performance of these kits among the most vulnerable age group to malaria is inadequate.

Materials and Methods:

In this cross-sectional study, 433 out-patients, aged <5 years with fever or history of fever were enrolled. Each candidate was tested for malaria parasitaemia using ACON; malaria pf. Thick and thin films were also prepared from the same finger prick blood for each candidate.

Result:

Malaria rapid diagnostic test had sensitivity of 8.3%, specificity of 100%, positive predictive value (PPV) of 100% and negative predictive value (NPV) of 74%. The sensitivity of MRDT increased with increasing age. This effect of age on sensitivity was statistically significant (P = 0.007). Similarly parasite density had significant effect on the sensitivity of MRDT (P = <0.001).

Conclusion:

Histidine-rich protein-2 based MRDT is not a reliable mean of diagnosing malaria in the under-five age children with acute uncomplicated malaria.     

IMMUNOCHROMATOGRAPHIC TEST: A NEW DIMENSION IN DIAGNOSIS OF PLASMODIUM FALCIPARUM MALARIA

75 patients with clinical features suggestive of malaria were studied to evaluate the efficacy of immunochromatographic test (ICT), which detects histidine rich protein-2 antigen secreted by Plasmodium falciparum (Pfhrp-2), as against direct microscopy. There were 40 cases of P falciparum malaria, 14 cases of P vivax malaria and 21 cases of non-malarial fevers. Direct microscopy could detect 27(67.5%) P falciparum cases but failed to detect 13 cases (32.5%) whereas ICT could detect 35(87.5%) P falciparum cases out of 40 but failed to detect 5(12.5%) cases. All the P vivax cases and non-malarial fever cases were negative for ICT. The sensitivity and specificity of ICT is 87.5% and 100% respectively where as the positive predictive value and the negative predictive value of the test is 100% and 87.5% respectively. It is concluded that ICT test is a good adjunct to blood smear studies in fever cases with neurological and multiorgan dysfunction and in antenatal ladies.Key Words: ICT, P falciparum     

Malaria in Pregnancy

Background

Malaria in pregnancy contributes to low birth weight and increased infant mortality.

Methods

The study included 416 pregnant women reporting with fever and the impact of malaria on pregnancy was assessed.

Result

The study revealed that the protozoal infection affects second trimester more commonly. It increases the chances of abortions, intrapartum foetal distress and meconium stained amniotic fluid.

Conclusion

Malaria is an important cause of feto-maternal morbidity during pregnancy.Key Words: Malaria in pregnancy, Plasmodium     

Malaria on the Move : Ecological Considerations for the Armed Forces

Background

Armed forces personnel deployed in the North Eastern states of India are vulnerable to falciparum malaria. This vulnerability increases during mobilization of troops.

Methods

Epidemiological case sheet was used for recording individual movement, clinical features and laboratory investigations of each case of malaria. Immunochromotography test (ICT) or Paracheck Pf was used as a rapid test for falciparum malaria at the regimental aid post (RAP). Subsequently, a case control approach was used to ascertain whether the cases of malaria differed significantly from healthy controls in observing antimalaria measures such as the use of mosquito nets, repellants and chemoprophylaxis.

Result

Nineteen out of 623 soldiers suffered from falciparum malaria during a short period of ten days during operational mobilization. Use of mosquito nets and repellants was significantly less among the cases as compared to healthy controls. There was no significant difference among the two groups regarding compliance with chemoprophylaxis.

Conclusion

A paradigm of “malaria on the move” or “operational malaria” has been proposed.Key Words: Malaria, Armed Forces, Mobilization     

Newer versus Conventional Methods in the Diagnosis of Malaria: A Comparison

Background

This study attempts to evaluate and compare the efficacy of polymerase chain reaction (PCR) and quantitative buffy coat (QBC) assay with conventional Giemsa stained peripheral blood smear (PBS) examination in the diagnosis of malaria. Methods: The study was conducted on 50 cases of smear positive malaria (group 1), 50 cases of clinically suspected malaria (group 2) and 15 healthy controls. All were subjected to Giemsa stain slide examination both thick and thin smear, QBC assay and PCR. PBS examination by Giemsa stain was taken as gold standard.

Result

In this study the overall sensitivity and positive predictive value (PPV) of QBC assay in group 1 was 100% and that of PCR was 60% and 100% respectively. In group 2 the sensitivity, specificity, PPV and NPV of QBC assay was 100% and that of PCR was 71%, 100%, 100% and 73% respectively as compared to the gold standard. All the 15 healthy controls were negative by all the three assays showing 100% specificity.

Conclusion

QBC assay was an excellent alternative to the conventional method as it is rapid and less time consuming and can directly demonstrate the parasite. Utility of PCR lies in species-specific diagnosis of falciparum malaria especially when there is a high degree of clinical suspicion and the report is negative by the other two methods.Key Words: Malaria, Diagnosis     

Malaria rapid diagnostic test in children: The Zamfara,Nigeria experience

Background:

Malaria remains a major cause of under-five morbidity and mortality in Nigeria, and prompt diagnosis occupies a strategic position in its management. Malaria rapid diagnostic test (RDT), a nontechnical, easy to perform test promises to meet this need. It is important to locally document the usefulness of the use of RDT in making prompt malaria diagnosis in children.

Objective:

To determine the prevalence of malaria and evaluate the diagnostic performance of malaria RDT kit in febrile under-five children presenting to a Tertiary Health Facility in Gusau, North-Western Nigeria.

Materials and Methods:

A cross-sectional study of children aged 6-59 months, evaluated for malaria in a tertiary health facility from August 2012 to January 2013. Information was obtained from care providers of all subjects with fever and a presumptive diagnosis of malaria. All subjects were investigated using Giemsa stain microscopy and Carestart™ malaria RDT.

Results:

The prevalence of malaria in 250 febrile under-five children was 54%. Three-quarter (79%) of the children received inappropriate nonrecommended antimalaria prior to their presentation, including 20% who received chloroquine. The overall sensitivity of RDT was 40.3%. The specificity, positive and negative predictive values were 89.6%, 81.8%, and 56.5%, respectively.

Conclusion:

Use of RDT should be encouraged for screening and diagnosis using a protocol such that febrile children with positive RDT results are confirmed as having malaria while those with negative results are further evaluated using microscopy.     

Polymorphic patterns of pfcrt and pfmdr1 in Plasmodium falciparum isolates along the Thai-Myanmar border

Objective

To investigate the distribution and patterns of pfcrt and pfmdr1 polymorphisms in Plasmodium falciparum (P. falciparum) isolates collected from the malaria endemic area of Thailand along Thai-Myanmar border.

Methods

Dried blood spot samples were collected from 172 falciparum malaria patients prior received treatment. The samples were extracted using chelex to obtain parasite DNA. PCR-RFLP was employed to detect pfcrt mutation at codons 76, 220, 271, 326, 356 and 371, and the pfmdr1 mutation at codon 86. Pfmdr1 gene copy number was determined by SYBR Green I real-time PCR.

Results

Mutant alleles of pfcrt and wild type allele of pfmdr1 were found in almost all samples. Pfmdr1 gene copy number in isolates collected from all areas ranged from 1.0 to 5.0 copies and proportion of isolates carrying>1 gene copies was 38.1%. The distribution and patterns of pfcrt and pfmdr1 mutations were similar in P. falciparum isolates from all areas. However, significant differences in both number of pfmdr1 copies and prevalence of isolates carrying>1 gene copies were observed among isolates collected from different areas. The median pfmdr1 copy number in P. falciparum collected from Kanchanaburi and Mae Hongson were 2.5 and 2.0, respectively and more than half of the isolates carried>1 gene copies.

Conclusions

The observation of pfmdr1 wild type and increasing of gene copy number may suggest declining of artesunate-mefloquine treatment efficacy in P. falciparum isolates in this border area.     

Dipstick urinalysis findings in children with Plasmodium falciparum in the South Tongu District: A case-control study

Background:

Malaria ranks among the major health and developmental challenges facing some of the poorest countries in tropical and sub-tropical regions across the globe. We determined urinary abnormalities and its relationship with parasite density in children ≤12 years with Plasmodium falciparum infection.

Materials and Methods:

From December 2013 to March 2014, we randomly recruited 116 participants comprising 58 malaria patients (cases) and 58 healthy controls from the Comboni Mission and the Sogakope District Hospitals both in the South Tongu district. Blood was collected for the estimation of hemoglobin and total white blood cells; thick and thin blood films were used for the determination of malaria parasite density. Urine was collected for the measurement of the various biochemical components using the automated urine analyzer. A pretested questionnaire was used to obtain demographic and clinical data.

Results:

Urine protein (P < 0.001), blood (P < 0.001), bilirubin (P < 0.001), urobilinogen (P < 0.001), and ketones (P = 0.001) were significantly higher in individuals with P. falciparum infection than in healthy controls. Proteinuria (P = 0.247; r = 0.155), hematuria (P = 0.142; r = 0.195), bilirubinuria (P = 0.001; r = 0.438), urobilinogenuria (P = 0.876; r = 0.021), and ketonuria (P = 0.136; r = 0.198) were positively correlated with malaria parasite density; however, only bilirubinuria was significantly higher at higher parasitemia.

Conclusion:

Malaria has a significant effect on the chemical composition of urine with bilirubin positively correlated with parasite density. Dipstick urinalysis can be used together with light microscopy in resource-limited malaria-endemic areas to accurately diagnose falciparum malaria infection.     

Hematological indices in febrile neonates with malaria parasitaemia in Calabar

Background:

Normal hematological indices has been determined in Nigerian newborns and found to be lower compared to their Caucasian counterparts. This was attributed to genetic factors. Malaria is endemic in Nigeria and is one of the major causes of ill health and death. Anemia is an important manifestation of malaria. Resistance by malaria parasites to antimalarial drug exacerbates the situation by continuous hemolysis.

Aim:

To determine the hematological indices in febrile newborn with malaria parasitemia.

Materials and Methods:

One-hundred fifty neonates (0-28 days) with fever admitted into the Newborn Unit of University of Calabar Teaching Hospital, over a 6 months period, were recruited consecutively. Blood film for malaria parasites and samples for full blood count were obtained and sent to the laboratory before commencement of the treatment. Data analysis was with SPSS version 14.

Results:

One-hundred fifty babies were recruited into the study. Most (85.3%) of the babies were aged ≤7 days. Six babies (4%) had malaria parasitemia. Plasmodium falciparum was the only species identified. All the babies that had parasitemia were anemic (mean hemoglobin [Hb] concentration of 12.6 g/dl) even when parasite count was low (average of 30.6/µl) though this could not be attributed solely to malaria. None of these neonates was transfused. All the other hematological indices were within the normal range of healthy newborn population irrespective of parasitization.

Conclusion:

Neonatal malaria does occur in our environment. While it does not affect the white blood indices, it lowers neonatal Hb. It is recommended that Hb concentration be estimated in newborns with malaria to reduce infant morbidity and mortality in our environment.     

Antiplasmodial,cytotoxic activities and characterization of a new naturally occurring quinone methide pentacyclic triterpenoid derivative isolated from Salacia leptoclada Tul. (Celastraceae) originated from Madagascar

Objective

To validate scientifically the traditional use of Salacia leptoclada Tul. (Celastraceae) (S. leptoclada) and to isolate and elucidate the structure of the biologically active compound.

Methods

Bioassay-guided fractionation of the acetonic extract of the stem barks of S. leptoclada was carried out by a combination of chromatography technique and biological experiments in viro using Plasmodium falciparum and P388 leukemia cell lines as models. The structure of the biologically active pure compound was elucidated by 1D and 2D NMR spectroscopy and mass spectrometry.

Results

Biological screening of S. leptoclada extracts resulted in the isolation of a pentacyclic triterpenic quinone methide. The pure compound exhibited both in vitro a cytotoxic effect on murine P388 leukemia cells with IC₅₀ value of (0.041±0.020) µg/mL and an antiplasmodial activity against the chloroquine-resistant strain FC29 of Plasmodium falciparum with an IC₅₀ value of (0.052±0.030) µg/mL. Despite this interesting anti-malarial property of the lead compound, the therapeutic index was weak (0.788). In the best of our knowledge, the quinone methide pentacyclic triterpenoid derivative compound is reported for the first time in S. leptoclada.

Conclusions

The results suggest that furthers studies involving antineoplastic activity is needed for the development of this lead compound as anticancer drug.     

A comparative laboratory diagnosis of malaria: microscopy versus rapid diagnostic test kits

Objective

To compare the two methods of rapid diagnostic tests (RDTs) and microscopy in the diagnosis of malaria.

Methods

RDTs and microscopy were carried out to diagnose malaria. Percentage malaria parasitaemia was calculated on thin films and all non-acute cases of plasmodiasis with less than 0.001% malaria parasitaemia were regarded as negative. Results were simply presented as percentage positive of the total number of patients under study. The results of RDTs were compared to those of microscopy while those of RDTs based on antigen were compared to those of RDTs based on antibody. Patients'' follow-up was made for all cases.

Results

All the 200 patients under present study tested positive to RDTs based on malaria antibodies (serum) method (100%). 128 out of 200 tested positive to RDTs based on malaria antigen (whole blood) method (64%), while 118 out of 200 patients under present study tested positive to visual microscopy of Lieshman and diluted Giemsa (59%). All patients that tested positive to microscopy also tested positive to RDTs based on antigen. All patients on the second day of follow-up were non-febrile and had antimalaria drugs.

Conclusions

We conclude based on the present study that the RDTs based on malaria antigen (whole blood) method is as specific as the traditional microscopy and even appears more sensitive than microscopy. The RDTs based on antibody (serum) method is unspecific thus it should not be encouraged. It is most likely that Africa being an endemic region, formation of certain levels of malaria antibody may not be uncommon. The present study also supports the opinion that a good number of febrile cases is not due to malaria. We support WHO''s report on cost effectiveness of RDTs but, recommend that only the antigen based method should possibly, be adopted in Africa and other malaria endemic regions of the world.     

Predictors of malaria in febrile children in Sokoto,Nigeria

Background:

Presumptive diagnosis of malaria is widespread, even where microscopy is available. As fever is very nonspecific, this often leads to over diagnosis, drug wastage and loss of opportunity to consider alternative causes of fever, hence the need to improve on the clinical diagnosis of malaria.

Materials and Methods:

In a prospective cross-sectional comparative study, we examined 45 potential predictors of uncomplicated malaria in 800 febrile children (0-12 years) in Sokoto, Nigeria. We developed a clinical algorithm for malaria diagnosis and compared it with a validated algorithm, Olaleye''s model.

Results:

Malaria was confirmed in 445 (56%). In univariate analysis, 13 clinical variables were associated with malaria. In multivariate analysis, vomiting (odds ratio, OR 2.6), temperature ≥ 38.5°C (OR 2.2), myalgia (OR 1.8), weakness (OR 1.9), throat pain (OR 1.8) and absence of lung crepitations (OR 5.6) were independently associated with malaria. In children over age 3 years, any 3 predictors had a sensitivity of 82% and specificity of 47% for malaria. An Olaleye score ≥ 5 had a sensitivity of 62% and a specificity of 51%.

Conclusion:

In hyperendemic areas, the sensitivity of our algorithm may permit presumptive diagnosis of malaria in children. Algorithm positive cases can be presumptively treated, and negative cases can undergo parasitological testing to determine need for treatment.     

A pilot study to evaluate the diagnostic accuracy of local terminology for malaria screening among children in rural Malawi

Background

Malaria is a serious health problem in Malawi. It is responsible for 43% of all out patient visits and 19% of all deaths occurring to children under five years of age. Rapid diagnosis and appropriate treatment can avert most malaria deaths. However this is not always possible in resource limited settings where functioning laboratories are almost nonexistent.

Methods

This paper assesses the accuracy of local terminology in detecting parasitemia in children using blood smears as the reference standard.

Results

The study observes that there are local terms that can be used as an inexpensive, readily available and easily implementable malaria screening test in Malawian children in rural areas. These terms include “malungo” (official name for malaria), “kutentha thupi” (hot body), “kutsegula m''mimba” (official term for diarrhoea) and “kukhosomola” (coughing). The local terms “malungo” and “kutentha thupi” yielded better results.

Conclusion

Although the local terminology produced results that are less than optimal, the study concludes that the knowledge of sensitivity and specificity of local terminology can be used by local healthcare practitioners to identify children who could benefit from malaria confirmation testing and presumptive treatment. The study, however, cautions that these terms should be used as an entry point to malaria case management as they do not distinguish the severity of the malaria infection and all of them produced a sensitivity of less than 50%.