Differences in automated depolarization patterns of Plasmodium falciparum and P. vivax malaria infections defined by the Cell-Dyn CD4000 haematology analyser

Of 1014 samples submitted for full blood count analysis and malaria screening, 854 were designated malaria-negative by blood film microscopy, 79 were unequivocally identified as Plasmodium vivax and 81 as P. falciparum. All samples were additionally analysed with the Abbott Cell-Dyn CD4000 haematology instrument, and leucocyte differential plots of 90 degrees polarized vs. 90 degrees depolarized (NEU-EOS plot) and 90 degrees depolarized vs. 0 degree light (EOS I plot) scatter were specifically examined for abnormal depolarization patterns. Depolarization pattern types were correlated with microscopy (species) results, and these correlations were consolidated by polymerase chain reaction analysis. All 854 microscopically-designated malaria-negative samples showed a type 1 (normal) CD4000 depolarization pattern. Abnormal pattern types 2, 3a and 3b were entirely restricted to one of the two malaria categories. Plasmodium falciparum malaria showed two CD4000 pattern types only; a 'normal' type 1 pattern was seen in 36/75 (48%) cases and the remaining 39 cases were all abnormal pattern type 3a. In contrast, most (79/85) P. vivax malaria cases showed a distinctive clustered EOS I population (types 2 and 3b patterns) that was not seen with P. falciparum. Automated depolarization analysis provides an effective means of detecting malaria-associated haemozoin, and the patterns of intracellular haemozoin further appear to provide species differentiation between P. falciparum and P. vivax.

[Study on detection of malaria parasite DNA by PCR-ELISA]

AIM

To present a new malaria diagnostic method based on detection of malaria parasite DNA by PCR-ELISA.

METHODS

According to the conserved sequence of Plasmodium SSUrRNA genes reported, a pair of primers in which one primer was biotinylated and another was unbiotinylated, suitable for DNA amplification of both falciparum and vivax malaria parasites were designed and synthesized. After denaturation and washing, the incorporated biotinylated product with avidin coated on plates previously was hybridized with the fluorescein-labelled oligonucleotide probes specific for Plasmodium falciparum or Plasmodium vivax. The color developed after adding POD conjugated with antibody to fluorescein and substrate can be semi-quantitated spectrophotometrically.

RESULTS

The thresholds of parasite density for the detection of Plasmodium falciparum and Plasmodium vivax by this test were shown to be as low as 4 and 10 parasites per microliter of blood, respectively and no cross reaction was seen in the detection of falciparum and vivax malaria parasites.

CONCLUSION

With promising sensitivity and specificity, this test can be used in malaria survey.

Comparison of two commercial assays with expert microscopy for confirmation of symptomatically diagnosed malaria

Conventional light microscopy has been the established method for malaria diagnosis. However, recently several nonmicroscopic rapid diagnostic tests have been developed for situations in which reliable microscopy may not be available. This study was conducted to evaluate the diagnostic performance of a recently introduced ICT Malaria Pf/Pv test. This assay detects Plasmodium falciparum histidine-rich protein 2 antigen (PfHRP-2) for P. falciparum diagnosis and pan-malarial antigen for P. vivax diagnosis. In this study we compared the performance of ICT Malaria Pf/Pv with microscopy of Giemsa-stained blood films and with an OptiMAL test that detects Plasmodium lactate dehydrogenase (pLDH) antigen. A total of 750 clinically suspected malaria patients were examined at local health centers in Kuwait. Both the antigen tests had a high degree of specificity (>98%) for detection of malaria infection. However, they were less sensitive than microscopy. Compared with microscopy the ICT Malaria PF/pf test failed to detect malaria infection in 93 (34%) of 271 malaria patients (11% of patients with P. falciparum and 37% of patients with P. vivax) and the OptiMAL test failed to detect malaria infection in 41 (15%) of 271 malaria patients (7% of patients with P. falciparum and 13% of patients with P. vivax). The sensitivities of the ICT Malaria Pf/Pv and OptiMAL tests for detection of P. falciparum infection were 81 and 87%, and those for detecting P. vivax were 58 to 79%, respectively. The sensitivity of the ICT Malaria Pf/Pv and OptiMAL tests decreased significantly to 23 and 44%, respectively, at parasite densities of <500/ micro l. Both of the tests also produced a number of false-positive results. Overall, the performance of the OptiMAL test was better than that of the ICT Malaria Pf/Pv test. However, our results raise particular concern over the sensitivity of the ICT Malaria Pf/Pv test for detection of P. vivax infection. Further developments appear necessary to improve the performance of the ICT Malaria Pf/Pv test.

Diagnosis of Plasmodium vivax malaria complicated by abnormal neurological imaging

The number of patients presenting with malaria in the United States has increased. This is attributable to the growing ease and popularity of overseas travel. We present a 41-year-old man diagnosed with Plasmodium vivax malaria after a 9-month symptom-free interval following return from an endemic area. The clinical picture was complicated by the results of neurological imaging that proved to be incidental and unrelated findings. Unfortunately, there are no pathognomonic signs or symptoms of malaria. The presenting complaints are often nonspecific and may be associated with a broad differential diagnosis. Thus, physicians must have a high index of suspicion and elicit a complete travel history to arrive at the correct diagnosis.

Short report: Failure of the OptiMAL rapid malaria test as a tool for the detection of asymptomatic malaria in an area of Thailand endemic for Plasmodium falciparum and P. vivax

We evaluated the efficacy of the OptiMAL assay in a cross-sectional malaria survey in western Thailand from April to August 2001. Expert microscopy of Giemsa-stained thick and thin blood films was used as the gold standard. Positive control lines were evident in 99% (1,128 of 1,137) of the assays tested. However, 34% (384 of 1,128) of assays produced an aberrant result (a positive P. falciparum-specific line and a negative panmalarial line). False-positive panmalarial and Plasmodium falciparum-specific lines occurred in 25.9% (270 of 1,042) and 60.3% (628 of 1,042) of microscopy-negative samples, respectively. Due to the preponderance of false-positive test results, it was necessary to develop subjective criteria for test positivity based on line intensity. For determination of assay performance during this study, we therefore considered all test lines that were scored as intermediate or strong as positive and lines that were faint as negative. Using these criteria, we determined that the sensitivity of the OptiMAL assay for P. falciparum was 25% with > 500 parasites/microl and 10.5% with > 100 parasites/microl, while for P. vivax, the sensitivity at the same parasite rates was 100% and 41.7%, respectively. Further studies are required to determine whether the problems we identified are limited to this particular lot of OptiMAL assays.

[Diagnosis of malaria with immunochromatographic test The Novara experience]

Microscopic detection of parasites has been the reference standard for malaria diagnosis for decades. Recently rapid antigen assays provide an effective tool for the detection of malaria in symptomatic patients. In Novara Maggiore della Carità Hospital we evaluated the efficacy of the ParaSight F test in patients with malaria.

Airport malaria: report of a case and a brief review of the literature

We report a case of Plasmodium vivax malaria in a patient who had not visited an endemic area. The ways in which malaria can be transmitted in non-endemic areas are discussed. By the elimination of other possibilities, the diagnosis of airport malaria was made. Airport malaria is a rare and often initially overlooked diagnosis. Since 1969, some 89 cases of airport malaria have been reported.

Haemozoin as a marker of placental parasitization

Both Plasmodium vivax and P. falciparum malaria can cause the delivery of low birthweight babies. In this report, we have quantitated haemozoin levels in placentas from women living on the Thai-Burmese border in a region of low transmission for both P. falciparum and P. vivax malaria from June 1995 to January 2000. P. falciparum malaria infections during pregnancy lead to the accumulation of haemozoin (malaria pigment) in the placenta, especially in infections near term and in primigravid pregnancies. Haemozoin concentration was not associated with adverse birth outcomes. Women with P. vivax infections during pregnancy do not have measurable levels of placental haemozoin suggesting that P. vivax-infected erythrocytes do not accumulate in the placenta as much as P. falciparum-infected ones.

Local transmission of Plasmodium vivax malaria--Virginia, 2002

Malaria transmission in the United States was largely eliminated during the mid-20th century; however, sporadic cases of locally acquired mosquito-transmitted malaria continue to occur. Since 1997, four separate probable mosquito-transmitted malaria outbreaks have been reported to CDC, including one from Virginia. This report describes the investigation of two cases of Plasmodium vivax malaria that occurred in northern Virginia in August 2002, and underscores the need for clinicians to consider the possibility of malaria in patients with fever of unknown origin.

Plasmodium vivax malaria presenting with severe thrombocytopenia

Plasmodium falciparum and Plasmodium vivax malaria are endemic infections in India and are commonly associated with mild hematological abnormalities. Severe thrombocytopenia is common in isolated falciparum and mixed falciparum/vivax malaria, but is very rare in isolated P.vivax infection. We hereby report a case of severe thrombocytopenia (platelet count of 8x10(9)/L) in a case of vivax malaria. This is only the second case ever reported in the literature of such profound thrombocytopenia in a case of isolated P.vivax malaria.

A direct sandwich ELISA to detect antibodies against the C-terminal region of merozoite surface protein 1 could be a useful diagnostic method to identify Plasmodium vivax exposed persons

We expressed a C-terminal 108-aa region of the Plasmodium vivax merozoite surface protein 1 (PvMSP1c) excluding the C-end transmembrane region in Escherichia coli in order to evaluate the antibody level to MSP in Korean malaria patients. We optimized a direct sandwich enzyme-linked immunosorbent assay (ELISA) method to simultaneously determine the total antibody levels, including IgG and IgM, to PvMSP1c. If the cut-off for seropositivity was determined as the mean+3SD of the antibody levels of the negative control group, the antibody levels were positive in 99.5% of the patient group (sensitivity 199/200). The antibody levels were negative in 99.4% of the negative control group (specificity 504/507). The positive reactions in the negative control group came from non-specific reactions, as confirmed by a competition assay. This direct sandwich ELISA for PvMSP1c antibody could prove to be a useful tool for the diagnosis of malaria patients and for blood screening in blood banks.

Cerebral involvement in benign tertian malaria

Although Plasmodium vivax usually causes benign uncomplicated malaria, it can occasionally result in severe disease with life-threatening, end-organ involvement generally seen with falciparum malaria. We report a case of cerebral malaria caused by P. vivax and review the literature on this subject.

Impact of microscopy error on estimates of protective efficacy in malaria-prevention trials

Microscopy is an imperfect reference standard used for malaria diagnosis in clinical trials. The purpose of this study was to provide an assessment of the accuracy of basic microscopy, to compare polymerase chain reaction (PCR)-based diagnosis with microscopy results, and to assess the effect of microscopy error on apparent protective efficacy. The sensitivity and specificity of basic, compared with expert, microscopy was determined to be 91% and 71%, respectively. In a clinical trial, agreement between PCR and microscopy results improved with expert confirmation of initial results. In a simulated 12-week trial with weekly routine malaria smears, a very high specificity (>99%) for each malaria smear was found to be necessary for an estimate of protective efficacy to be within 10%-25% of the true value, but sensitivity had little effect on this estimate. Microscopy error occurs and can affect clinical trial results.

[Two cases of mixed infection of malaria diagnosed by PCR method]

We here reported two Japanese cases of mixed infections of plasmodium species, whose DNAs were detected using the PCR test. One case was a 31 year-old male, who presented fever and fatigue, and had a travel history to Kenya, Cameroon and Indonesia. Smear test of his peripheral blood found the presence of Plasmodium vivax, while nested-PCR diagnosis detected the DNAs both P. vivax and Plasmodium malariae. The other was a 54 year-old female suffering from general fatigue. She had been treated with chloroquine for falciparum malaria in Indonesia two weeks before. Malaria antigen test showed positive although no Plasmodium organisms were found in the smear test. The nested PCR detected the DNA of Plasmodium ovale in addition to that of Plasmodium falciparum. In conclusion, the PCR test is helpful and useful for detection of mixed infections of Plasmodium species.

Performance of OptiMAL(R) in the diagnosis of Plasmodium vivax and Plasmodium falciparum infections in a malaria referral center in Colombia

Alternative, non-microscopic methods for the diagnosis of malaria have recently become available. Among these, rapid dipstick methods stand out. One such test, OptiMAL(R), is based on the immunochromatographic detection of Plasmodium lactate dehydrogenase (pLDH) and has the capacity to detect and distinguish infections caused by P. falciparum and Plasmodium sp. This capacity is particularly important in countries where different species of Plasmodium co-exist. In this study we evaluated the performance of OptiMAL(R) in an urban referral center for malaria diagnosis. Two sets of patients were included: one (n = 112) having predetermined infections with P. falciparum or P. vivax and individuals with negative blood smears; and another consisting of all eligible consecutive patients (n = 80) consulting for diagnosis at the referral center during one month. The overall diagnostic efficiency of OptiMAL(R) for both sets of patients was 96.9%. Efficiency was higher for P. vivax (98.1%) than for P. falciparum (94.9%). These results corroborate the diagnostic utility of OptiMAL(R) in settings where P. vivax and P. falciparum co-exist and support its implementation where microscopic diagnosis is unavailable and in circumstances that exceed the capacity of the local microscopic diagnosis facility.

Assessing the Parasight-F test in northeastern Papua, Indonesia, an area of mixed Plasmodium falciparum and Plasmodium vivax transmission

User-friendly, reliable, and inexpensive methods for diagnosing malaria are needed at the primary health care level. During a randomized treatment trial, the Parasight-F test was assessed on days 0, 3, 7, and 28 against standard light microscopy of Giemsa-stained thick blood smears for diagnosing Plasmodium falciparum parasitemia in patients with P. falciparum (n = 84) or P. vivax (n = 59) malaria. The median P. falciparum parasite count on day 0 was 2,373/microL (range = 20-74,432/microL). At the start of treatment, the Parasight-F test had a sensitivity of 95.2% (80 of 84; 95% confidence interval [CI] = 88.2-98.7), and a specificity of 94.9% (56 of 59; 95% CI = 85.8-98.9). On day 7, this test showed false-positive results in 17 (16.3%) of 104 patients (95% CI = 9.8-24.9). The Parasight-F test performed well when compared with light microscopy in detecting P. falciparum parasitemia in patients presenting with clinical malaria. However, the high false-positive rate on day 7 limits its use for patient follow-up.

Chloroquine for the treatment of uncomplicated malaria in Guyana

At a public hospital in Georgetown, Guyana, 44 patients seeking treatment for symptomatic, slide-confirmed malaria were given standard chloroquine (CQ) therapy and followed for 28 days. The patients apparently had pure infections with Plasmodium falciparum (14), P. vivax (13) or P. malariae (one), or mixed infections either of P. falciparum and P. vivax (17) or of P. falciparum, P. malariae and P. vivax (two). Each received supervised treatment with 10 mg CQ base/kg on each of days 0 and 1, and 5 mg/kg on day 2. On the day of enrollment (day 0), the patients complained of fever (100%), headache (100%), malaise (94%), myalgia (79%), nausea (67%), vertigo (49%) and vomiting (33%). Many (39%) were ill enough to confine themselves to bed. On day 4, fewer of the subjects complained of fever (15%), headache (15%), malaise (6%), myalgia (21%), nausea (6%), vertigo (24%) or vomiting (0%) despite the relatively high (>48%) risk of therapeutic failure. The cumulative incidence of parasitological failure against P. falciparum was 15% at day 4, 33% at day 7 and 48% at day 14. All of the P. vivax and P. malariae infections cleared before day 4 and none recurred by day 7. Two infections with P. vivax recurred later (on day 14 or 28) but in the presence of less than adequate, whole-blood concentrations of CQ plus desethyl-chloroquine (i.e. <100 ng/ml). Taken together, the results indicate a high risk of therapeutic failure of CQ against P. falciparum but also indicate that resistance to CQ in P. vivax occurs infrequently in Guyana.

Patterns of presentation of malaria in a tertiary care institute in Saudi Arabia

OBJECTIVE

The occurrence of malaria in a non-endemic area is an exceptional event. Review of clinical experience at the King Faisal Specialist Hospital & Research Centre (a tertiary medical centre located in a non-endemic area) demonstrated a relatively frequent infection rate among patients. We therefore examined circumstances that could contribute to the high rate of occurrence observed.

METHODS

We retrieved archived blood smears of patients diagnosed with malaria from the records of the Hematology Section of King Faisal Specialist Hospital & Research Centre, Riyadh, Kingdom of Saudi Arabia, followed by a review of the clinical records to extract demographic data, clinical presentations including history of proximate blood transfusion, and travel to, or residence in, areas endemic for malaria.

RESULTS

There were 217 patients diagnosed with malaria between 1978 and 1999, (1398 to 1419 Hejira calendar) resulting in an average yearly frequency of 9.86 cases. Males were 2.6 times more frequently affected than females (p<0.001). The majority of patients were infected through natural means, either by residence in endemic areas (N=83) or by travel to one (N=90). A significant minority, 44 (20.3%), became infected through blood transfusion. The majority of blood transfusion-induced malaria occurred in patients who were immunocompromised for various reasons, mostly related to dysfunction of the hematopoietic system or to major surgical insult. The most frequently implicated organism was Plasmodium falciparum, accounting for 74.2% of cases, whilst Plasmodium vivax accounted for 25.4%.

CONCLUSION

We demonstrate that patients presenting with malaria are more likely to be males who have been exposed during travel to endemic areas or through blood transfusion. In all cases, Plasmodium falciparum is the most likely organism to be implicated.

Comparison of three antigen detection methods for diagnosis and therapeutic monitoring of malaria: a field study from southern Vietnam

OBJECTIVES

To compare the sensitivity, specificity and post-treatment persistence of three commonly used rapid antigen detection methods.

METHOD

We studied 252 Vietnamese patients aged from 4 to 60 years, 157 with falciparum and 95 with vivax malaria and 160 healthy volunteers. An initial blood sample was taken for microscopy, and OptiMAL, immunochromatographic test (ICT) malaria P.f./P.v. and Paracheck-Pf tests. Patients with falciparum malaria were treated with an artesunate-based combination regimen and those with vivax malaria received chloroquine. Eighty-seven patients with falciparum malaria who were initially positive for one of the antigen tests and who remained blood smear-negative underwent follow-up testing over 28 days.

RESULTS

Paracheck-Pf was the most sensitive test for Plasmodium falciparum (95.8% vs. 82.6% for ICT malaria P.f./P.v. and 49.7% for OptiMAL). Specificities were all 100%. For vivax malaria, OptiMAL performed better than ICT malaria P.f./P.v. (sensitivities 73.7% and 20.0%, respectively), with 100% specificity in both cases. All tests had low sensitivities (< or = 75.0%) at parasitaemias < 1000/microl regardless of malaria species. During follow-up, Paracheck-Pf remained positive in the greatest proportion of patients, especially at higher parasitaemias (> 10,000/microl). Residual OptiMAL positivity occurred only in a relatively small proportion of patients (< 10%) with parasitaemias > 10,000/microl during the first 2 weeks after treatment.

CONCLUSIONS

Although microscopy remains the gold standard for malaria diagnosis, Paracheck-Pf may prove a useful adjunctive test in uncomplicated falciparum malaria in southern Vietnam. OptiMAL had the lowest sensitivity for P. falciparum but it might have a use in the diagnosis of vivax malaria and perhaps to monitor efficacy of treatment for falciparum malaria where microscopy is unavailable.

Field evaluation of the ICT Malaria Pf/Pv immunochromatographic test for the detection of asymptomatic malaria in a Plasmodium falciparum/vivax endemic area in Thailand

Rapid antigen assays provide an effective tool for the detection of malaria in symptomatic patients. However, the efficacy of these devices for detecting asymptomatic malaria, where parasite levels are normally significantly lower than in symptomatic patients, is less well established. We evaluated the efficacy of a new combined Plasmodium falciparum-Plasmodim vivax immunochromatographic test (ICT Malaria Pf/Pv) in a cross-sectional malaria survey of the village of Ban Kong Mong Tha, Kanchanaburi Provice, Thailand, from August to December 2000. A total of 1,976 bleeds were made from 559 individuals over the course of the study. Blinded microscopy of thick and thin blood films was used as the gold standard; all discordant and 10% of concordant results were cross-checked. Of 1,976 ICT Malaria Pf/Pv dipsticks tested, 98.3% (n = 1,943) performed as expected, as evidenced by the appearance of the control line. The ICT Malaria Pf/Pv test was both sensitive (100.0%) and specific (99.7 %) for the diagnosis of falciparum malaria with parasitemias of > or = 500 trophozoites/microL; however, only 15.9% (13/82) of infected individuals had parasitemia rates this high. When P. falciparum parasitemia rates were < 500/microL, the sensitivity of the diagnosis was only 23.3%, with a positive predictive value (PPV) and a negative predictive value (NPV) of 76.2 and 97.2%, respectively. The ICT Malaria Pf/Pv test was specific, but not sensitive, for the diagnosis of vivax malaria with parasite rates of > or = 500 trophozoites/microl, with sensitivity, specificity, PPV, and NPV of 66.7%, 99.9%, 66.7%, and 99.9%, respectively. At parasite rates of < 500/microL, corresponding values were 0.0%, 99.9%, 0%, and 95.1%. Because of the relatively high cost of these assays, low parasite rates found in the majority of asymptomatic individuals, and low sensitivity of this assay with rates of < 500/microl, use of this assay as a tool for active case detection is of limited value in western Thailand.

Evaluation of a dipstick test for the rapid diagnosis of imported malaria among patients presenting within the network TropNetEurop

Lack of experience on the part of involved laboratory personnel frequently complicates swift diagnosis of imported falciparum malaria in non-endemic areas. Diagnostic tools based on the dipstick principle for the detection of plasmodial histidine-rich protein 2 have been marketed for several years and have been extensively evaluated. Recently, a test kit capable of detecting antigen of Plasmodium falciparum and P. vivax has been introduced. In order to evaluate this newly available tool, specimens from 664 patients were screened during the course of a prospective multicentre study within the European Network on Imported Infectious Disease Surveillance (TropNetEurop). Among the screened specimens, samples from 82 patients (12.3%) were positive for falciparum malaria using expert microscopy. A further 17 samples were positive for vivax malaria. The evaluated test kit performed with a sensitivity of 87.8% and a specificity of 99% for detection of falciparum malaria. Respective values for vivax malaria were 76.5% and 100%. Dipstick tests have the potential of improving the speed and accuracy of the diagnosis of falciparum malaria, especially if non-specialized laboratories are involved. However, decreased values of sensitivity and specificity, in comparison with expert microscopy, still impose a clear limit on the usefulness of the currently available kits.

Plasmodium vivax: parasitemia determination by real-time quantitative PCR in Aotus monkeys

Plasmodium vivax and Plasmodium falciparum are the two prevalent human malaria species. A Colombian P. vivax wild strain has been adapted in Aotus nancymaae monkeys for use in further biological and immunological studies. We present data validating a real-time PCR assay quantifying P. vivax parasitemia, using the small subunit ribosomal RNA genes as an amplification target. P. vivax species-specific primers were designed on the 18S ribosomal gene V8 region, for amplifying both asexual and sporozoite ssrRNA genes. The assay detects amplification products bound to fluorescent SYBR-Green I dye using Perkin-Elmer GeneAmp-5700-SDS. Linear range standard curves from 6 DNA concentration logs (+0.99 correlation coefficients) were obtained. Standard curves were constructed using a plasmid containing target gene for real-time PCR amplification. This P. vivax specific assay is very sensitive, having a three parasite detection limit, and is reproducible and accurate. It involves a "closed-tube" PCR, avoids time-consuming post-PCR manipulation, and decreases potential PCR contamination.

Performance appraisal of rapid on-site malaria diagnosis (ICT malaria Pf/Pv test) in relation to human resources at village level in Myanmar

Logistic, economic and technical factors limit rapid access to microscopic confirmation of symptomatic diagnosis of malaria in many rural areas in endemic countries such as Myanmar. A study was conducted to evaluate a rapid on-site immunochromatographic test (ICT Malaria Pf/Pv) for detection of Plasmodium falciparum and P. vivax in two villages in the Taikkyi region of Myanmar. The ICT Malaria tests were performed by a volunteer health worker (VHW) in Yae-Aye-San village and by a professionally trained midwife (MW) in Kankone village. A total of 1000 symptomatic patients participated in the study by providing blood samples for an ICT test and for microscopy. The ICT performance indices, relative to microscopy, were better for the trained MW compared with the less experienced VHW. For P. falciparum and/or P. vivax infections, the sensitivities were 82.7% for the VHW compared with 93.7% for the MW. For P. falciparum infections, the sensitivities were 82.2% for the VHW and 91.3% for the MW, while the corresponding values for P. vivax infections were 66.7 and 79%, respectively. Although the test kit appeared to perform better in more experienced hands, this study questions whether this difference is related to the use of the ICT Malaria Pf/Pv test kit, or related to other factors such as differences in the quality of blood slides prepared by the VHW and MW for microscopic examination. Overall, the results suggest that a rapid diagnostic assay such as the ICT Malaria Pf/Pv test kit can be used in rural settings by relatively inexperienced persons, such as VHWs, with a reasonable degree of sensitivity, thus providing on-site confirmation of symptomatic diagnosis of malaria.

Control of malaria: a successful experience from Viet Nam

OBJECTIVE

To follow malaria prospectively in an ethnic minority commune in the south of Viet Nam with high malaria transmission and seasonal fluctuation, during malaria control interventions using insecticide-treated bednets (ITBNs) and early diagnosis and treatment (EDT) of symptomatic patients.

METHODS

From 1994 onwards the following interventions were used: distribution of ITBNs to all households with biannual reimpregnation; construction of a health post and appointment of staff trained in microscopic diagnosis and treatment of malaria; regular supply of materials and drugs; annual cross-sectional malaria surveys with treatment of all parasitaemic subjects, and a programme of community involvement and health education. Surveys were held yearly at the end of the rainy season. During the surveys, demographic data were updated. Diagnosis and treatment of malaria were free of charge. Plasmodium falciparum infection was treated with artesunate and P. vivax infection with chloroquine plus primaquine.

FINDINGS

The baseline survey in 1994 recorded 716 inhabitants. Of the children under 2 years of age, 37% were parasitaemic; 56% of children aged 2-10 years, and 35% of the remaining population were parasitaemic. P. falciparum accounted for 73-79% of these infections. The respective splenomegaly rates for the above-mentioned age groups were 20%, 56%, and 32%. In 1999, the proportion of parasitaemic subjects was 4%, 7% and 1%, respectively, of which P.falciparum contributed 56%. The splenomegaly rate was 0%, 5% and 2%, respectively.

CONCLUSIONS

A combination of ITBNs and EDT, provided free of charge, complemented by annual diagnosis and treatment during malaria surveys and community involvement with health education successfully brought malaria under control. This approach could be applied to other regions in the south of Viet Nam and provides a sound basis for further studies in other areas with different epidemiological patterns of malaria.

Probable autochthonous Plasmodium vivax malaria transmission in Michigan: case report and epidemiological investigation

In September 1995, a Michigan resident with no history of international travel was diagnosed with Plasmodium vivax infection, and local mosquito-borne transmission was suspected. An epidemiological investigation did not identify additional cases of local transmission, and there was no apparent link to the 12 imported malaria cases detected in the region. Potential sites of nighttime outdoor exposure included a campground in a swampy area, close to a racetrack frequented by international travelers, some of whom were known to come from countries with malaria transmission. Entomological investigation identified Anopheles spp. larvae and adults near the campsite. Summer temperatures 4.2 degrees C above average would have contributed to shortened maturation time of P. vivax within the insect vector, increasing the likelihood of infectivity. These investigations indicated that this patient probably acquired P. vivax infection through the bite of a locally infected Anopheles spp. mosquito. Physicians need to consider malaria as a possible cause of unexplained febrile illness, even in the absence of international travel, particularly during the summer months.

Adaptation of a strain of Plasmodium vivax from India to New World monkeys, chimpanzees, and anopheline mosquitoes

A strain of Plasmodium vivax from India was adapted to develop in splenectomized Saimiri boliviensis, Aotus lemurinus griseimembra, A vociferans, A. nancymai, A. azarae boliviensis, hybrid Aotus monkeys, and splenectomized chimpanzees. Infections were induced via the inoculation of sporozoites dissected from the salivary glands of Anopheles stephensi and An. dirus mosquitoes to 12 Aotus and 8 Saimiri monkeys; transmission via the bites of infected An. stephensi was made to 1 Aotus monkey and 1 chimpanzee. The intravenous passage of infected erythrocytes was made to 9 Aotus monkeys and 4 chimpanzees. Gametocytes in 13 Aotus monkeys and 4 chimpanzees were infectious to mosquitoes. Infection rates were markedly higher in mosquitoes fed on chimpanzees. PCR studies on 10 monkeys injected with sporozoites revealed the presence of parasites before their detection by microscopic examination. The India VII strain of P. vivax develops in Aotus and Saimiri monkeys and chimpanzees following the injection of parasitized erythrocytes, or sporozoites, or both. The transmission rate via sporozoites to New World monkeys of approximately 50% may be too low for the testing of sporozoite vaccines or drugs directed against the exoerythrocytic stages. However, the strain is highly infectious to commonly available laboratory-maintained anopheline mosquitoes. Mosquito infection is especially high when feedings are made with gametocytes from splenectomized chimpanzees.

Ex-vivo short-term culture and developmental assessment of Plasmodium vivax

A simple reproducible method for short-term ex-vivo Plasmodium vivax culture is presented in which glucose, ascorbic acid, thiamine, hypoxanthine, and 50% human AB+ serum are added to the standard P. falciparum in-vitro culture medium. Culture of freshly obtained blood samples from patients with acute vivax malaria with > 0.5% parasitaemia resulted in > 95% complete schizogony. Culture could be continued for 5-6 cycles without the addition of red cells. Criteria for staging the erythrocytic development of P. vivax in the first schizogonic cycle based on synchronous ex-vivo culture are presented. The asexual cycle was divided into 7 morphological stages: tiny ring (0-6 h), small ring (6-12 h), large ring (12-18 h), early trophozoite (18-28 h), late trophozoite (28-36 h), early schizont (36-42 h) and mature schizont (42-48 h). This simple method of culturing P. vivax ex vivo is suitable for antimalarial susceptibility and immunoparasitology studies.

Application of yeast enolase as antigen for immunodiagnosis of malaria

In 1998, we reported that Plasmodium falciparum (Pf) enolase was useful as the capture antigen for the immunodiagnosis of malaria. In the present study, we modified a fluorescence-ELISA for the diagnosis of malaria by applying yeast enolase or rabbit muscle enolase as antigen. Sera from 67 falciparum malaria patients and 15 vivax malaria patients were tested by the method. Positivity rates of the former was 82.1% against yeast enolase antigen and 90.5% against rabbit muscle enolase antigen, and those of latter was 93.3% against both enolase antigens. Mean antibody level (RFU values) of sera from falciparum and vivax malaria patients were significantly higher than those from healthy individuals. There was a significant correlation between anti-yeast and anti-rabbit muscle enolase antibody level (RFU values) in the group of falciparum subjects (r = 0.401, p<0.001). A significant correlation between RFU values against yeast enolase antigen and indirect fluorescent antibody titers against crude Pf antigen in the same subjects was recognized (r = 0.518, p<0.001). Longitudinal changes of RFU values against yeast enolase for the following 4 weeks after admission were also examined for sera from falciparum malaria patients. Patients with more severe malaria showed increasing RFU values as the clinical courses progressed. However, in the mild cases, each RFU value stayed unchanged during the course. We concluded that yeast and rabbit muscle enolase could be appropriately used as antigen for the immunodiagnosis of malaria.

[Evaluation of the OptiMal test in the diagnosis of imported malarial outbreak]

The OptiMal test is an immuno-chromatographic dipstick test that permits indiscriminate detection of Plasmodium falciparum and other species of human malaria. The purpose of this study was to evaluate the efficacy of the test for diagnosis of imported malaria. A total of 244 patients with a presumptive diagnosis of imported malaria in France were included during the study period. The reference test, i.e., combined thick and thin blood films, demonstrated infection by Plasmodium falciparum in 58 cases, Plasmodium vivax in 12, P. ovale in 8 and Plasmodium malariae in 2. The OptiMal test detected only 46 of the 55 Plasmodium falciparum cases. The sensitivity of the test for diagnosis of that species was 80%, its specificity was 98%, and its positive and negative predictive values were 95 and 93% respectively. Parsitemia studies showed poor test reliability for densities lower than 150/ul. Detection of other species was accurate in 21 out of 22. The results of this study demonstrate that the current version of the OptiMal test should be used with great caution for the diagnosis of malarial infection in hospital practice.

Development and optimization of polymerase chain reaction-based malaria diagnostic methods and their comparison with quantitative buffy coat assay

Polymerase chain reaction (PCR)-based assays targeting the small-subunit rRNA were developed and evaluated, allowing for the simultaneous diagnosis of Plasmodium falciparum and Plasmodium vivax DNA in human blood samples. The PCR methods and quantitative buffy coat (QBC) were compared in 402 patients. The heminested PCR method showed a sensitivity of 97.4%, which was superior to the sensitivity of the QBC method (91.7%, P < 0.05), to simple PCR (84.6%, P < 0.001), and to PCR with digoxigenin labeling (PCR-DIG) (88.5%, P < 0.001). The PCR-DIG and QBC analyses were more sensitive than simple PCR (P < 0.003 and P < 0.05, respectively). There was no significant difference between the sensitivities of the QBC assay and the PCR-DIG assay. The specificity for the 3 PCR-based methods was 100%, superior to the specificity calculated for the QBC assay (88.95%, P < 0.009). The frequency of a positive result in groups from endemic areas but without detectable parasitemia increased, in order, from simple PCR, QBC test, PCR-DIG, to heminested PCR. An association between a positive PCR result and a history of malaria was also found. Taken together, these data suggest that this technology could be further developed to screen people with oligoparasitemia and to monitor malaria treatment.

The detection of Plasmodium falciparum and P. vivax in DNA-extracted blood samples using polymerase chain reaction

Seventeen pairs of published primer sets were compared for their relative sensitivity to detect malaria DNA extracted from blood samples, which were obtained from Pakistani patients suffering from malaria. The primer sets investigated consisted of: (i) 9 pairs of direct primers and 3 sets of nested primers for detecting Plasmodium falciparum, (ii) 2 pairs of direct primers and 2 sets of nested primers for detecting P. vivax, and (iii) 1 set of multiplex primers for detecting both P. falciparum and P. vivax, simultaneously. After a miniscreen of 9 DNA-extracted blood samples using the 17 primer sets stated above, 5 primer sets were short-listed (based on their superior sensitivity) and used for a maxi-screen of DNA extracted from 126 microscopy-positive blood samples from Pakistan, with the following results. (i) For the detection of P. falciparum, the direct primer pair 'PF1 + PF2' gave a sensitivity of 95% and the nested primer set 'RIT405 + RIT406/RIT371 + RIT372' gave a sensitivity of 97%. (ii) For the detection of P. vivax, the direct primer pair 'Forward + Reverse' and the nested primer set 'PLF + UNR/PLF + VIR' both gave a sensitivity of 94%. (iii) The nested multiplex primer set 'rPLU5 + rPLU6/rFAL1 + rFAL2 + rVIV1 + rVIV2' gave a sensitivity of 97% and 96% for P. falciparum and P. vivax, respectively. It was concluded that the nested multiplex primer set was the most optimal primer set to use for the detection of malaria DNA extracted from blood samples. Furthermore, the nested multiplex primer set has the advantage of simultaneously detecting and differentiating between P. vivax and P. falciparum.

Diagnostic performance characteristics of rapid dipstick test for Plasmodium vivax malaria

We compared the diagnostic performance characteristics of newly developed method, the rapid dipstick test, which provides colorimetric determination by developing antibody to the lactate dehydrogenase enzyme of parasites, with conventional standard thick-blood film examination. For the rapid test, OptiMAL commercial kits were used. The results were also evaluated with clinical findings from patients. The parasites were determined by microscopic examination of thick-blood films from 81 patients with vivax malaria from southeastern Anatolia, Turkey. The OptiMAL test results were found to be negative in five patients who were diagnosed clinically and through thick-film testing as having vivax malaria. There was no false positivity observed with the OptiMAL test. We concluded that this rapid malaria test has a lower level of sensitivity than the classical thick-blood-film test for malaria, but that these methods have equal specificity.

A trial for a DNA diagnosis of Plasmodium vivax malaria recently reemerging in the Republic of Korea using microtiter plate hybridization assay

The polymerase chain reaction-based microtiter plate hybridization (PCR-MPH) assay was utilized for a DNA diagnosis of Plasmodium vivax malaria, which has recently reemerged in the Republic of Korea. The subjects were 18 parasite-proven patients and 5 healthy controls. Follow-up blood samples were collected from 4 patients after a standard course of treatment. Polymerase chain reaction and electrophoresis of all the patients' blood showed a prominent band at the 138 base pair area, but not in the controls or after treating the patients. Hybridization of the PCR products with known species-specific probes of the 18S rRNA of various malaria species revealed strong positive reactions against the Plasmodium vivax-specific probe (absorbance 1.30-1.90 at 405 nm) in all of the patients. The absorbance was positively correlated with the degree of blood parasitemia, but with a borderline significance. Sequencing of the probe region of the Korean P. vivax revealed no significant variations from the typical P. vivax. The results show that the PCR-MPH is a highly useful technique for the DNA diagnosis of Korean vivax malaria.

PCR-based ELISA technique for malaria diagnosis of specimens from Thailand

We performed a field evaluation of polymerase chain reaction (PCR)-based enzyme-linked immuno-sorbent assays (ELISA) for the diagnosis of malaria. A commercially available PCR-ELISA microplate hybridization (MPH) assay was used. Blood specimens were collected from 300 volunteers seeking care at malaria clinics in Thailand. Examination of 200 high power fields by Giemsa-stained thick and thin smear (GTTS) revealed 51 P. falciparum (Pf), 45 P. vivax (Pv), seven mixed Pf-Pv infections. These plus a random sample of 48 GTTS-negative specimens were selected for this study. All 151 specimens were processed for parasite DNA extraction and assayed by PCR-MPH. The target DNA sequence of the 18S small subunit ribosomal RNA (SSUrRNA) gene was amplified by PCR and hybridized with species-specific probes for Pf, Pv, P. malariae (Pm) and P. ovale (Po) immobilized in the wells of the microtiter plate and detected by colorimetric assay. Colour development was assessed at an optical density (OD) of 405 nm. An absorbance reading of > or = 0.1 was used as a positive cut-off. In comparison with GTTS results, PCR-MPH sensitivity was 91.4% (53/58, 95% CI 84.2-98.6) for Pf, 94.2% (49/52, 87.9-100) for Pv and specificity was 95.8% (46/48, 95% CI 90.2-100). There was statistically significant positive correlation between parasite densities < or = 7000/microl blood and absorbance reading, suggestive of PCR-MPH being semiquantitative. PCR-MPH also detected additional Pf and Pv cases as well as Pm and Po.

Western blot diagnosis of vivax malaria with multiple stage-specific antigens of the parasite

Western blot analysis was performed to diagnose vivax malaria using stage-specific recombinant antigens. Genomic DNA from the whole blood of a malaria patient was used as templates to amplify the coding regions for the antigenic domains of circumsporozoite protein (CSP-1), merozoite surface protein (MSP-1), apical merozoite antigen (AMA-1), serine repeat antigen (SERA), and exported antigen (EXP-1) of Plasmodium vivax. Each amplified DNA fragment was inserted into a pGEX-4T plasmid to induce the expression of GST fusion protein in Escherichia coli by IPTG. The bacterial cell extracts were separated on 10% SDS-PAGE followed by western blot analysis with patient sera which was confirmed by blood smear examination. When applied with patient sera, 147 (91.9%) out of 160 vivax malaria, 12 (92.3%) out of 13 falciparum malaria, and all 9 vivax/falciparum mixed malaria reacted with at least one antigen, while no reactions occurred with 20 normal uninfected sera. In the case of vivax malaria, CSP-1 reacted with 128 (80.0%) sera, MSP-1 with 102 (63.8%), AMA-1 with 128 (80.0%), SERA with 115 (71.9%), and EXP-1 with 89 (55.6%), respectively. We obtained higher detection rates when using 5 antigens (91.9%) rather than using each antigen solely (55.6-80%), a combination of 2 (76.3-87.5%), 3 (85.6-90.6%), or 4 antigens (89.4-91.3%). This method can be applied to serological diagnosis, mass screening in endemic regions, or safety test in transfusion of prevalent vivax malaria.

Evaluation of rapid immunocapture assays for diagnosis of Plasmodium vivax in Korea

The rapid immunocapture assays, OptiMal and ICT, were evaluated from 87 individuals for the diagnosis of malaria infections directly from whole blood. A total of 87 individuals was examined for malaria parasites by microscopic examination of Giemsa-stained blood smears, and 65 cases were positive for Plasmodium vivax by microscopy. Correspondingly, the OptiMal test identified malaria infection in 45 cases (69.2%) of microscopy positive cases. Of these, two cases were misinterpreted as Plasmodium falciparum, whereas ICT detected P. vivax infection in 29 (44.6%) patients. We would like to propose that rapid immuno capture assays are an easy method that can serve as a useful tool in addition to microscopy for the diagnosis of malaria, but sensitivity is not yet satisfactory for diagnosis of P. vivax in Korea.

False-positive serological tests in acute malaria

A range of serological tests, including rapid plasma reagin (RPR), Widal test, enzyme-linked immunosorbent assay (ELISA) for human immunodeficiency virus (HIV)-1 and -2, direct Coombs' test (DCT), and rheumatoid factor (RF) were performed in a well-characterised cohort of 100 patients with acute malaria (Plasmodium vivax infection: 31 patients; P. falciparum infection: 69 patients). Twenty-five healthy volunteers from a similar area were used as controls. Three patients from the severe P. falciparum group died, the remainder of the patients recovered completely. A large proportion of these patients showed false-positive serological reactions during the acute stage of infection, which became negative on re-testing, four weeks after recovery. In tropical countries such as India, where malaria is endemic, results of serological tests should be interpreted with caution in a patient with pyrexia of unknown origin (PUO).

Persistent ICT malaria P.f/P.v panmalarial and HRP2 antigen reactivity after treatment of Plasmodium falciparum malaria is associated with gametocytemia and results in false-positive diagnoses of Plasmodium vivax in convalescence

A problem with rapid Plasmodium falciparum-specific antigen histidine-rich protein 2 (HRP2) detection tests for malaria is the persistence of antigen in blood after the disappearance of asexual-stage parasitemia and clinical symptoms, resulting in false-positive (FP) test results following treatment. The ICT P.f/P.v immunochromatographic test detects both HRP2 and a panmalarial antigen (PMA) found in both P. falciparum and Plasmodium vivax. To examine posttreatment antigen persistence with this test and whether persistent sexual-stage forms (gametocytes) are a cause of FP tests after treatment, we compared serial antigen test results with microscopy results from patients symptomatic with P. falciparum malaria in Indonesia for 28 days following treatment with chloroquine (CQ; n = 66), sulfadoxine-pyrimethamine (SP; n = 36), and artesunate plus sulfadoxine-pyrimethamine (ART + SP; n = 15). Persistent FP antigenemia following SP treatment occurred in 29% (HRP2) and 42% (PMA) of the patients on day 7 and in 10% (HRP2) and 23% (PMA) on day 14. The high rates of persistent HRP2 and PMA antigenemia following CQ and SP treatment were strongly associated with the presence of gametocytemia, with the proportion with gametocytes on day 7 posttreatment being significantly greater in those with FP results than in those with true-negative PMA and HRP2 results. Gametocyte frequency on day 14 post-SP treatment was also greater in those with FP PMA results. Following SP treatment, PMA persisted longer than HRP2, giving an FP diagnosis of P. vivax in up to 16% of patients on day 14, with all FP P. vivax diagnoses having gametocytemia. In contrast, PMA was rapidly cleared following ART + SP treatment in association with rapid clearance of gametocytemia. Gametocytes appear to be an important cause of persistent posttreatment panmalarial antigenemia in areas of endemicity and may also contribute in part to persistent HRP2 antigenemia following treatment.

Comparison of the OptiMAL rapid test with routine microscopic examination of Giemsa-Stained Thick Blood Film for diagnosis of malaria

The OptiMAL is a rapid immunodiagnostic test developed by Flow Inc., Portland, Oreg. for diagnosis and differentiation of P. falciparum and non P. falciparum malaria infection. It has been based on detection of circulating parasite lactate dehydrogenase enzyme (pLDH), produced by live Plasmodium parasites. The purpose of this study was to compare the efficacy of the OptiMAL test with routine microscopic examination of Giemsa-Stained Thick Blood Film (routine GS-TBF) for the diagnosis of malaria at a local malaria clinic in a hyperendemic area of Thailand by using a standard GS-TBF (standard GS-TBF) as reference. One hundred and seventy five patients attending the clinic were recruited; 50, 42 and 83 were falciparum malaria, vivax malaria and non-malaria patients, respectively. Compared with the reference, the OptiMAL test had sensitivities of 92 per cent and 97.6 per cent, whereas, the routine GS-TBF had sensitivities of 81.3 per cent and 81 per cent for the detection of P. falciparum and P. vivax, respectively. Both tests showed no false positive resulting in 100 per cent specificities. However, the OptiMAL test was able to detect only 20 per cent of infection with less than 200 parasitaemia/microlitre. It was also shown in our study that the OptiMAL test was advantageous in follow-up of the treatment outcome. No false positive occurred among 40 follow-up cases. The OptiMAL test detected malaria infection more accurately than the routine GS-TBF (p < 0.05) and was simple, easy to perform and rapid. It is an alternative tool for the diagnosis of malaria in a hyperendemic area where experienced microscopists are not available.

Comparison of IsoCode STIX and FTA Gene Guard collection matrices as whole-blood storage and processing devices for diagnosis of malaria by PCR

We compared two collection devices, IsoCode and FTA, with whole blood for the diagnosis of malaria by PCR (n = 100). Using whole blood as the reference standard, both devices were sensitive for the detection of single-species malaria infections by PCR (> or =96%). However, the detection of mixed infections was suboptimal (IsoCode was 42% sensitive, and FTA was 63% sensitive).

Acute respiratory distress syndrome complicating Plasmodium vivax malaria

Malaria is one of the most common infectious diseases in the world, and severe respiratory complications have been described mainly in association with Plasmodium falciparum. We describe a case of acute respiratory distress syndrome complicating infection with P. vivax in the setting of relatively low parasitemia in a 47-yr-old woman after a brief trip to Papua New Guinea. A review of the literature shows that pulmonary complications of P. vivax are rare but occur more frequently than generally acknowledged. Pathogenic mechanisms of these complications are discussed.

Imported Plasmodium vivax malaria in France: geographical origin and report of an atypical case acquired in Central or Western Africa

A total of 73 cases of Plasmodium vivax infections acquired in Western or Central Africa were diagnosed on microscopical criteria in French travellers from 1995 to 1998. We report a case of P. vivax infection in a non immune traveller confirmed by polymerase chain reaction and presenting an atypical P. ovale morphology. The infection was acquired in Western or Central Africa. These microscopical observations, together with the molecular evidence for P. vivax in Western and Central Africa suggest that P. vivax is transmitted in this area despite lacking the Duffy receptor in autochthonous population.

Diagnosis of malaria in a remote area of the Philippines: comparison of techniques and their acceptance by health workers and the community

OBJECTIVE

To compare the efficacies of remote symptom-based diagnosis of malaria, rapid diagnostic tests and microscopy in an area of low endemicity in the Philippines.

METHODS

In Trial I, 350 symptomatic patients were tested within their villages using malaria Plasmodium falciparum (Pf)/Plasmodium vivax (Pv) immunochromatographic tests (ICT tests) and blood films stored and read under local conditions. The slides were later restained and read. In Trial II, unsupervised volunteer barangay health workers prepared ICT tests and slides after brief training. These slides were read at rural health units. Twenty-seven barangay health workers and 72 community members were later questioned about the three diagnostic strategies.

FINDINGS

A history of fever alone was sensitive (95.4%) but poorly specific (16.5%) for predicting parasitaemia. The inclusion of other symptoms reduced the sensitivity to below 85%, while specificity remained low. The axillary temperature was poorly predictive. ICT tests achieved high sensitivity (97.9%) but many cases indicated as positive by ICT tests were negative by microscopy. Further analysis of these cases in Trial I indicated that ICT tests were detecting low-level parasitaemias missed by microscopy, and that local microscopy had poor accuracy. ICT tests were well accepted and accurately performed by barangay health workers.

CONCLUSION

These tests meet a strong desire in the community for blood-based diagnosis and may increase the compliance and treatment-seeking behaviour of patients.

Severe acute renal failure in malaria

BACKGROUND

We have noticed a recent rise in the incidence and severity of acute renal failure (ARF) in malaria.

AIM

To study the incidence, severity and outcome of ARF in malaria.

SETTING AND DESIGN

It is a retrospective analysis of data of one year from a tertiary medical centre in a metropolitan city.

MATERIALS AND METHODS

Patients with ARF and smear positive malaria were evaluated.

STATISTICAL ANALYSIS

Results were expressed as mean, range and standard deviation.

RESULTS

Out of 402 detected smear positive malaria, 24 had ARF. Eighteen were of the age group 21-40 years. Plasmodium falciparum (PF) was detected in 16, Plasmodium vivax in three, and mixed infection in five. Non-oliguric ARF was seen in 14. Eighteen showed severe ARF (Serum creatinine >5 mg%). Twenty-two patients needed dialysis. Prolonged ARF lasting for 2-6 weeks was seen in eight. Seventeen patients recovered completely, while seven showed fatal combination of disseminated intravascular coagulation (DIC), acute respiratory distress syndrome (ARDS), severe ARF and PF malaria. No response was seen to chloroquine and artesunate given alone and twenty patients required quinine.

CONCLUSION

ARF necessitating dialysis was seen in 92% of patients with ARF in malaria. PF infection, severe ARF, DIC and ARDS were poor prognostic factors. Resistance was noted to both chloroquine and artesunate.