High prevalence of asymptomatic Plasmodium falciparum infection in Gabonese adults

Plasmodium falciparum, the most common malarial parasite in sub-Saharan Africa, accounts for a high number of deaths in children less than five years of age. In malaria-endemic countries with stable transmission, semi-immunity is usually acquired after childhood. For adults, severe malaria is rare. Infected adults have either uncomplicated malaria or asymptomatic parasitemia. During a period of one year, we screened 497 afebrile males to investigate the prevalence of asymptomatic P. falciparum parasitemia in villages near Lambaréné, Gabon by use of three different methods. A total of 52% of the individuals had parasites detected by a subtelomeric variable open reading frame polymerase chain reaction (stevor-PCR), 27% of the rapid diagnostic test results were positive, and 12% of the thick blood smears with low parasitemias had P. falciparum. Most positive cases were only detected by the stevor-PCR. Asymptomatic P. falciparum parasitemia in adults living in a malaria-endemic country is frequent.     

The epidemiology of malaria in a population surrounding Madang, Papua New Guinea

Malaria is prevalent throughout coastal and lowland Papua New Guinea. Recent changes, including a shift from predominance of Plasmodium vivax to Plasmodium falciparum, appearance of chloroquine-resistant P. falciparum and decreased effectiveness of vector control programs have been observed. Epidemiological features of malaria were studied through four six-month surveys of a population of 16,500 in Madang Province from 1981-1983. Baseline data on parasitology, splenic enlargement, serology, hemoglobin levels, prevalence of 4-aminoquinolines, utilization of mosquito nets and incidence of fever were collected for use in future evaluation of malaria control measures including possible field trials of an antimalarial vaccine. Prevalence of parasitemia (all species, all ages) varied from 35.0% to 42.7% over the four surveys each of which covered a random sample of 25% of the population. The ratio of parasite species was: P. falciparum 70:P. vivax 25:P. malariae 5 in the dry seasons, shifting slightly in favor of P. falciparum during the wet seasons. Intense year-round transmission was indicated by decreasing parasite prevalence and splenic enlargement with age, low density asymptomatic parasitemias and high prevalence of antimalarial antibodies (i.e., greater than 80% of the population over five years of age was ELISA-positive). Levels of endemicity varied geographically, presence of 4-aminoquinolines in urine samples was relatively common (12.7% positive) and chloroquine resistance was widespread (81.6% in vitro, 46.6% in vivo).     

Increased severe anemia in HIV-1-exposed and HIV-1-positive infants and children during acute malaria

OBJECTIVE: Since the primary hematological complication in both pediatric HIV-1 and malaria is anemia, co-infection with these pathogens may promote life-threatening severe malarial anemia (SMA). The primary objective of the study was to determine if HIV-1 exposure [HIV-1(exp)] and/or HIV-1 infection [HIV-1(+)] increased the prevalence of SMA in children with acute malaria. DESIGN: The effect of HIV-1 exposure and HIV-1 infection on the prevalence of SMA (hemoglobin < 6.0 g/dl), parasitemia (parasites/microl), and high-density parasitemia (HDP, >or= 10 000 parasites/mul) was investigated in children 相似文献   

Parasite multiplication potential and the severity of Falciparum malaria

The multiplication rates and invasiveness of Plasmodium falciparum parasites isolated from adult Thai patients hospitalized with uncomplicated malaria (n=34) were compared with those from persons with severe malaria (n=42). To simulate severe malaria and control for host effects, the in vitro cultures were adjusted to 1% parasitemia and used the same red blood cell donor. P. falciparum isolates from persons with severe malaria had initial cycle multiplication rates in vitro that were 3-fold higher than those from uncomplicated malaria (median [95% confidence interval], 8.3 [7. 1-10.5] vs. 2.8 [1.7-3.9]; P=.001). Parasites causing severe malaria exhibited unrestricted red blood cell invasion, whereas those from uncomplicated malaria were restricted to a geometric mean of 40 (31%-53%) of red blood cells. P. falciparum parasites causing severe malaria were less selective and multiplied more at high parasitemias than those causing uncomplicated malaria.     

Malaria prophylaxis using azithromycin: a double-blind, placebo-controlled trial in Irian Jaya, Indonesia.

New drugs are needed for preventing drug-resistant Plasmodium falciparum malaria. The prophylactic efficacy of azithromycin against P. falciparum in malaria-immune Kenyans was 83%. We conducted a double-blind, placebo-controlled trial to determine the prophylactic efficacy of azithromycin against multidrug-resistant P. falciparum malaria and chloroquine-resistant Plasmodium vivax malaria in Indonesian adults with limited immunity. After radical cure therapy, 300 randomized subjects received azithromycin (148 subjects, 750-mg loading dose followed by 250 mg/d), placebo (77), or doxycycline (75, 100 mg/d). The end point was slide-proven parasitemia. There were 58 P. falciparum and 29 P. vivax prophylaxis failures over 20 weeks. Using incidence rates, the protective efficacy of azithromycin relative to placebo was 71.6% (95% confidence interval [CI], 50.3-83.8) against P. falciparum malaria and 98.9% (95% CI, 93.1-99.9) against P. vivax malaria. Corresponding figures for doxycycline were 96.3% (95% CI, 85.4-99.6) and 98% (95% CI, 88.0-99.9), respectively. Daily azithromycin offered excellent protection against P. vivax malaria but modest protection against P. falciparum malaria.     

Imported malaria in a Singapore hospital: clinical presentation and outcome.

OBJECTIVE: To evaluate the clinical presentation and outcome of imported malaria. METHODS: A retrospective chart review was conducted of patients with imported malaria admitted to the Communicable Disease Centre (CDC), Singapore (a 130-bed tertiary referral center) from January 1992 to December 1993. An imported case was defined as a smear-positive infection that was acquired in another country. RESULTS: Among 200 malaria patients hospitalized at CDC, 168 imported cases (137 males and 31 females, 131 nonresidents and 37 residents) were studied. The mean age was 31.6 6 10.5 years. The countries visited were India (49.4%), Indonesia (16.7%), and Bangladesh (13%). Five patients had chemoprophylaxis and 36 patients had experienced previous malaria infection. The predominant symptoms were fever (97.6%), chills (79.2%), and rigors (67.9%). Hepatomegaly was detected in 56 (33.3%) and splenomegaly in 49 patients (29.2%). Plasmodium vivax was present in 132 patients, Plasmodium falciparum in 29, and mixed P. vivax and P. falciparum in 7 patients. Parasitemia ranged from 0.1% to 8.0%. Of the vivax cases, 130 were treated with chloroquine, followed by primaquine in 123 patients. Quinine was given to 36 patients (29 falciparum malaria and 7 mixed infections). Median time to fever defervescence was 2 days. Complications occurred in three patients (2 with shock and 1 with pulmonary edema). According to World Health Organization gravity criteria, body temperature over 40 degrees C was detected in six patients, bilirubinemia higher than 50 mmol/L in nine, parasitemia over 5% in five, glycemia less than 2.2 mmol/L in two patients. There were five relapses. No death was recorded. CONCLUSION: Plasmodium vivax is the most common cause of imported malaria, with the majority acquired from the Indian subcontinent. Only a few patients presented with severe malaria.     

The influence of zinc supplementation on morbidity due to Plasmodium falciparum: a randomized trial in preschool children in Papua New Guinea

Zinc is crucial for normal immune function and can reduce morbidity from multiple infectious diseases. To determine the influence of zinc on malaria morbidity we conducted a randomized placebo-controlled trial of daily zinc supplementation in children residing in a malaria endemic region of Papua New Guinea. A total of 274 preschool children aged 6 to 60 months were given 10 mg elemental zinc (n = 136) or placebo (n = 138) for 6 days a week for 46 weeks. Slide-confirmed malaria episodes were detected by surveillance of cases self-reporting to a local health center. Cross-sectional surveys were conducted at the beginning, middle, and end of the study to assess infection rates, parasite density, spleen enlargement, and hemoglobin levels. Zinc supplementation resulted in a 38% (95% CI 3-60, P = 0.037) reduction in Plasmodium falciparum health center-based episodes, defined as parasitemia > or = 9200 parasites/microl with axial temperature > or = 37.5 degreesC or reported fever. Episodes accompanied by any parasitemia were also reduced by 38% (95% CI 5-60, P = 0.028), and episodes with parasitemia > or = 100,000/microl were reduced by 69% (95% CI 25-87, P = 0.009). There was no evidence of the effects of zinc on Plasmodium vivax morbidity or on health center attendance for causes other than P. falciparum. Zinc had no consistent effect on cross-sectional malariometric indices. Although P. falciparum prevalence tended to be lower at the end of the study in children given the placebo, such changes were absent at the mid-study survey. These results suggest that improved dietary zinc intake may reduce morbidity due to P. falciparum.     

Variants in the toll-like receptor signaling pathway and clinical outcomes of malaria

BACKGROUND: Malaria is one of the most significant infectious diseases in the world and is responsible for a large proportion of infant deaths. Toll-like receptors (TLRs), key components of innate immunity, are central to countering infection. Variants in the TLR-signaling pathway are associated with susceptibility to infectious diseases. METHODS: We genotyped single nucleotide polymorphisms (SNPs) of the genes associated with the TLR-signaling pathway in patients with mild malaria and individuals with asymptomatic Plasmodium infections by means of polymerase chain reaction. RESULTS: Genotype distributions for the TLR-1 I602S differed significantly between patients with mild malaria and persons with asymptomatic infection. The TLR-1 602S allele was associated with an odds ratio (OR) of 2.2 (P= .003; P(corrected)= .015) for malaria among patients with mild malaria due to any Plasmodium species and 2.1 (P= .015; P(corrected)= .75) among patients with mild malaria due to Plasmodium falciparum only. The TLR-6 S249P SNP showed an excess of homozygotes for the TLR-6 249P allele in asymptomatic persons, compared with patients with mild malaria due to any Plasmodium species (OR 2.1; 95% confidence interval [CI], 1.1- 4.2; P= .01; P(corrected)= .05), suggesting that the TLR-6 249S allele may be a risk factor for malaria (OR, 2.0; 95% CI, 1.1-3.7; P=0.01; P(corrected)= .05). The TLR-9 -1486C allele showed a strong association with high parasitemia (P< .001). CONCLUSIONS: Our findings indicate that the TLR-1 and TLR-6 variants are significantly associated with mild malaria, whereas the TLR-9-1486C/T variants are associated with high parasitemia. These discoveries may bring additional understanding to the pathogenesis of malaria.     

Parasite diversity in adult patients with cerebral malaria: a hospital-based, case-control study

Thirty adult patients with cerebral malaria (CM) were recruited for this study. Two clinical groups were used as controls: those with mild malaria (n = 20) and asymptomatic volunteers (n = 20). Thick and thin blood smears were examined for detection of Plasmodium falciparum and estimating infection intensity. A nested polymerase chain reaction (PCR) using allele-specific primers for merozoite surface protein gene was used to determine the parasite diversity of Plasmodium falciparum causing CM. Plasmodium falciparum was detected in blood smears of all malaria patients. No significant difference in parasite count was found between the groups. Thirteen (65%) of the asymptomatic volunteers had a positive PCR for P. falciparum. Multiple alleles were found in 17 (58.6%) patients with CM, but only in 7 (35.6%) with uncomplicated malaria. Multiple alleles were also found in 6 (46.2%) of the 13 PCR-positive asymptomatic individuals. We could not identify a specific strain or strains of P. falciparum that showed a significant association with disease severity. Therefore, we assume that the development of CM in adults residing in endemic areas is more dependent on strain multiplicity rather than on a specific strain or strains of P. falciparum, and that the parasite intensity has no relationship with disease severity. Asymptomatic adults may repeatedly be exposed to low levels of a wide range of different strains during low transmission season and acquire sub-patent parasitemia. This may also confer premunition that renders them relatively resistant to CM.     

Possible role of PGD_2 in malaria infections

Objective:To preliminarily investigate the possible role of prostaglandin D_2(PGD_2) in malaria infections.Methods:Blood and urinary samples(n=120 each) were collected from Thai patients with Plasmodium falciparum(P.falciparum) with moderate(n=26) and high(n=4) parasitemia,patients with Plasmodium vivax(P.vivax)(n=30),patients with fever associated with other infections(n=30),and healthy subjects(n=30).PGD_2 concentrations in plasma and urinary samples of healthy subjects,patients with fever associated with other infections and patients with malaria were determined using Prostaglandin D2-MOX express EIA kit(Cayman Chemical,USA).Results:The possible association between PGD_2 and malaria infections is clearly demonstrated with PGD_2 concentration in urine.The urinary PGD_2 concentrations were relatively high(about 5-fold) in patients with P.falciparum with moderate parasitemia and P.vivax infections compared with other groups.Furthermore,the concentration in patients with P.falciparum with moderate parasitemia and P.vivax infection were significantly higher than that in healthy subjects and patients with fever associated with other infections.Conclusions:Urinary PGD_2 concentrations may offer a more dependable and useful tool for predicting malaria severity.Confirmation is this preliminary finding is required with a larger sample size.     

A survey on malaria in mobile Cambodians in Aranyaprathet,Sa Kaeo Province,Thailand

A cross-sectional survey of the malaria prevalence among mobile Cambodians in Aranyaprathet, at the Thai-Cambodia border, was conducted in November 2000. A total of 666 asymptomatic, mobile Cambodians who worked as traders and laborers were studied. The overall prevalence rate was 2.4%, with 93.75% of the infections being due to Plasmodium vivax and 6.25% due to Plasmodium falciparum. Almost all cases had low level of parasitemia (1+) and no sexual stages were found. Factors associated with malaria infection included being male, being in the 10-59 year age group, having a lower level of education and frequent trans-border crossing. Both groups of migrant workers (traders and laborers) had an equal chance of infection.     

Endemic malaria in the Peruvian Amazon region of Iquitos

A cross-sectional study was conducted in the Peruvian Amazon to test the hypothesis that a reservoir of asymptomatic malaria parasitemic patients would form the basis for continuing malaria endemicity in the region. Active surveillance yielded a Plasmodium spp. slide-positive prevalence of 4.2% (43 of 1,023) and a polymerase chain reaction (PCR)-positive prevalence of 17.6% (144 of 819). Plasmodium vivax prevalence was 2.9% and 14.2% while Plasmodium falciparum prevalence was 1.3% and 2.6% by microscopy and PCR, respectively. Approximately two-thirds of slide-positive and one-fourth of PCR-positive people were symptomatic. Anemia was associated with slide positivity (P < 0.001) and PCR positivity for P. falciparum (P = 0.003). Sensitivity of field microscopy and agreement between field and reference laboratory microscopists were low, arguing for using PCR for epidemiologic investigation and malaria control. While these data confirm recent findings from the Brazilian Amazon suggesting that sufficient numbers of asymptomatic malaria parasitemic patients are present to form a persistent reservoir for continuous reinfection within the Peruvian Amazon region, these results also indicate that clinical immunity in human populations can be driven in malaria-endemic regions that do not have high intensity malaria transmission.     

Prevalence of malaria as co-infection in HIV-infected individuals in a malaria endemic area of southeastern Nigeria

BACKGROUND & OBJECTIVE: The present study was conducted on the prevalence of malaria as co-infection amongst 'asymptomatic HIV' and 'symptomatic HIV' subjects to see if such prevalence deviated from that commonly reported in apparently health individuals in same locality. METHODS: A prospective study that involved 196 participants grouped according to their HIV status as: 'asymptomatic HIV seropositive group' (n = 101); 'symptomatic HIV seropositive group' (n = 48) and 'control HIV-seronegative group (n = 47). Blood samples collected from the participants were used for double HIV screening by rapid immunoassay technique and immunochromatographic technique, and for the diagnosis of Plasmodium falciparum malaria using rapid P. falciparum antigen detection method. RESULTS: The result showed that the prevalence of P. falciparum malaria as a co-infection amongst the asymptomatic HIV seropositive group was 12 (11.8%) and amongst the symptomatic HIV seropositive group was 16 (33.3%). However, the prevalence rate of P. falciparum malaria amongst the control HIV seronegative group was 5 (10.6%) and the combined burden of P. falciparum malaria amongst both groups of HIV seropositives was 28 (18.9%). INTERPRETATION & CONCLUSION: The present study observed different prevalence rates of P. falciparum malaria amongst the three groups. The prevalence was tripled in symptomatic HIV seropositive group. This shows a clear departure from possible obtainable prevalence of malaria infection alone in this malaria endemic area. Due to the mortality rates associated with malaria infection in an endemic area, it may be necessary that routine malaria screening be adopted as part of the management policy to check the co-infection.     

Demographic risk factors for severe and fatal vivax and falciparum malaria among hospital admissions in northeastern Indonesian Papua

Between January 1998 and December 2000, the Jayapura Provincial Public Hospital in northeastern Indonesian New Guinea (Papua) admitted 5,936 patients with a diagnosis of malaria. The microscopic diagnosis at admission was Plasmodium falciparum (3,976, 67%), Plasmodium vivax (1,135, 19%), Plasmodium malariae (8, < 1%), and mixed species infections (817, 14%). Approximately 9% (367) of patients were classified as having severe malaria (277 P. falciparum, 36 P. vivax, 53 mixed infections, and 1 P. malariae) and 88 died (79 P. falciparum/mixed infections and 9 P. vivax). Risk of fatal outcomes among severe malaria patients was indistinguishable between those with falciparum versus vivax malaria (OR = 0.89; P = 0.771). Compared with non-pregnant women, pregnant women showed no higher risk of severe malaria (P = 0.643) or death caused by severe malaria (P = 0.748). This study compares admissions per population (based on census data), parasitemia, morbidity, and mortality among children versus adults, pregnant versus non-pregnant women, and urban/suburban versus rural residents.     

Efficacy of trimethoprim-sulfamethoxazole compared with sulfadoxine-pyrimethamine plus erythromycin for the treatment of uncomplicated malaria in children with integrated management of childhood illness dual classifications of malaria and pneumonia

In Malawi, trimethoprim-sulfamethoxazole (TS) is the recommended first-line treatment for children with Integrated Management of Childhood Illness dual classifications of malaria and pneumonia, and sulfadoxine-pyrimethyamine (SP) plus five days of treatment with erythromycin (SP plus E) is the recommended second-line treatment. Using a 14-day, modified World Health Organization protocol, children with dual IMCI classifications of malaria and pneumonia with Plasmodium falciparum parasitemia were randomized to receive TS or SP plus E. Clinical and parasitologic responses and gametocytemia prevalence were obtained. A total of 87.2% of children receiving TS and 80.0% receiving SP plus E reached adequate clinical and parasitologic responses (ACPRs) (P = 0.19). Severely malnourished children were less likely to achieve ACPRs than those better nourished (relative risk = 3.34, P = 0.03). Day 7 gametocyte prevalence was 55% and 64% among children receiving TS and SP plus E, respectively (P = 0.19). Thus, TS and SP plus E remain efficacious treatment of P. falciparum malaria in this setting. However, patient adherence and effectiveness of five days of treatment with TS is unknown.     

The combination of indoor residual spraying and insecticide-treated nets provides added protection against malaria compared with insecticide-treated nets alone

Both insecticide-treated bed nets (ITNs) and indoor residual spraying (IRS) reduce malaria in high malaria transmission areas. The combined effect of these interventions is unknown. We conducted a non-randomized prospective cohort study to determine protective efficacy of IRS with ITNs (ITN + IRS) compared with ITNs alone (ITN only) in preventing Plasmodium falciparum parasitemia. At baseline, participants provided blood samples for malaria smears, were presumptively treated for malaria, and received ITNs. Blood smears were made monthly and at sick visits. In total, 1,804 participants were enrolled. Incidence of P. falciparum parasitemia in the ITN + IRS and ITN only groups was 18 and 44 infections per 100 persons-years at risk, respectively (unadjusted rate ratio = 0.41; 95% confidence interval [CI] = 0.31-0.56). Adjusted protective efficacy of ITN + IRS compared with ITN only was 62% (95% CI = 0.50-0.72). The combination of IRS and ITN might be a feasible strategy to further reduce malaria transmission in areas of persistent perennial malaria transmission.     

Comparison of field and expert laboratory microscopy for active surveillance for asymptomatic Plasmodium falciparum and Plasmodium vivax in western Thailand

Microscopy of Giemsa-stained thick and thin films by a skilled microscopist has remained the standard laboratory method for the diagnosis of malaria. However, diagnosis of malaria with this method is problematic since interpretation of results requires considerable expertise, particularly at low parasite levels. We compared the efficacy of "field" and "expert laboratory" microscopy for active surveillance of Plasmodium falciparum and P. vivax in western Thailand. Field microscopy consisted of an approximately five-minute read (50-100 fields) of a thick film at x700 using a natural light source, whereas expert laboratory microscopy consisted of a 20-minute read (number of parasites per 500 leukocytes) at x1,000 using a high-quality, well-maintained microscope with an artificial light source. All discordant and 20% of concordant results were cross-checked blindly. A total of 3,004 blood films collected between May and November 2000 were included in the study, of which 156 (5.2%) were positive for P. falciparum, 177 (5.9%) for P. vivax, and 4 (0.1%) for both P. falciparum and P. vivax by expert microscopy. A total of 84.4% (135 of 160) of the P. falciparum-positive slides and 93.9% of the P. vivax-positive slides had a parasitemia of less than 500/microL. Field microscopy was specific (99.3%) but not sensitive (10.0%) for the diagnosis of P. falciparum malaria, with a positive predictive value (PPV) of 43.2% and a negative predictive value (NPV) of 95.1%. The corresponding specificity and sensitivity for the diagnosis of P. vivax malaria were 99.2% and 7.1%, respectively, with a PPV of 38.7% and an NPV of 93.9%. Field microscopy, as defined in this study, is not an effective method for active malaria surveillance in western Thailand, where prevalence and parasitemia rates are low.     

Falciparum malaria parasitemia index for predicting severe malaria

Introduction: While hyperparasitemia is considered an important indicator for the development of severe malaria, there is currently no consensus on the quantitative definition of hyperparasitemia. This study was conducted to establish a cutoff point for peripheral parasitemia among patients with Plasmodium falciparum malaria, to define severe malaria. Methods: The clinical presentations of 200 uncomplicated P. falciparum malaria, and 189 severe P. falciparum malaria, patients, admitted to the Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand, were analyzed. Results: A peripheral parasitemia of 0.5% was found to be the optimal cutoff point for defining severe malaria, demonstrating highest sensitivity (85.1%), specificity (62.0%), and accuracy (73.2%). Conclusion: Symptoms of severe falciparum malaria depend on many factors. For the definition of hyperparasitemia in areas of low or seasonal transmission, peripheral parasitemia of 0.5% might be considered a cutoff point for discrimination between severity levels. This value might be useful for the clinical management of malaria, particularly in hypo‐endemic areas, unstable transmission areas, and other areas with similar transmission patterns.     

High rate of mixed and subpatent malarial infections in southwest Nigeria.

The rate of malarial parasitemia in children and adults was assessed by microscopy and the polymerase chain reaction in a holoendemic area in Nigeria. A high rate of subpatent Plasmodium falciparum parasitemia (19.6%) was found. Plasmodium malariae and P. ovale infections were common in a rural area (26.1% and 14.8%) but were observed sporadically in individuals from an urban area. Simultaneous infections with P. falciparum, P. malariae, and P. ovale were frequent in the rural area (11.7% triple infections). The rate of triple infections was higher than expected from the prevalences of each species (P < 0.00001). Spleen enlargement was associated with mixed infections of P. falciparum and P. malariae (odds ratio [OR] = 5.9, 95% confidence interval [CI] 3.0-11.7) and less frequently observed in individuals without detectable parasitemia (OR = 0.06, 95% CI = 0.01-0.3). Spleen enlargement and titers of antibodies to schizonts were positively correlated with parasite densities. The results also suggest that in some individuals a long-lasting subpatent parasitemia might occur.     

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.