Human parasitoses of the Malili area, South Sulawesi (Celebes) province, Indonesia.

A biomedical survey was conducted in 9 villages in the Malili area of South Sulawesi, Indonesia. Blood specimens were examined for malaria and microfilariae; stool specimens were examined for intestinal parasites. Malaria parasitemias were rare; Plasmodium falciparum was detected in 10 and P. vivax in 11 of 985 blood smears. Malayan filariasis was endemic to all villages surveyed. The overall prevalence of detectable microfilaremias was 15%, varying from 34% in Kawata to 1% in Nuha. Microfilarial densities, expressed as MfD50 averaged 8.0 and varied from 1.1 in Timampu to 16.0 in Karabbe. Intestinal parasites were common. Although Schistosoma japonicum was not found, 97% of the examined had one or more intestinal parasites as follows: Ascaris lumbricoides (74%), Trichuris trichiura (65%), hookworm (62%), Entamoeba coli (38%), Endolimax nana (10%), Entamoeba histolytica (6%), Iodamoeba bütschlii (4%), Entamoeba hartmanni (3%), Giardia lamblia (2%) Chilomastix mesnili (1%) and Enterobius vermicularis (1%). Strongyloides stercoralis larvae and Hymenolepis nana eggs were detected once each and heterophyid-like eggs were detected twice.     

Parasitology survey and seroepidemiology of amoebiasis in South Kalimantan (Borneo), Indonesia.

A parasitology surevy was conducted among inhabitants of 7 villages in 3 regencies in South Kalimantan Province, Indonesia. A total of 2,169 stool specimens, 2,756 blood smears and 1,027 serum specimens were obtained, representing samples from approximately 10%, 12% and 5% of the population, respectively. One to 8 different intestinal parasitic infections were detected in 97% of the people. Those parasites most frequently found were Trichuris trichiura (83%), Ascaris lumbricoides (79%), and hookworm (65%), followed by Entamoeba coli (37%), Endolimaxnana (12%), Entamoeba histolytica (12%), Iodamoeba bütschlii (11%), Giardia lamblia (5%), Entamoeba hartmanni (2%), Chilomastix mesnili (2%). Other parasites found were Enterobius vermicularis, Strongyloides stercoralis, Capillaria sp., Echinostoma sp., Hymenolepis diminuta, and Trichomonas hominis. Giardia lamblia was found more often in younger people and Entamoeba coli, Iodamoeba bütschlii and hookworm in the older age group. Ascaris lumbricoides occurred more frequently in females, and hookworm in males. Plasmodium vivax and Plasmodium falciparum were found in the blood smears of 4.4% of the people, mostly in the younger age groups. Seroepidemiological studies on amoebiasis were done by use of the indirect hemagglutination test with antigens prepared from the HK9 strain of Entamoeba histolytica maintained in axenic cultures. The frequency distribution of the reciprocal antibody titers showed a bimodal distribution with 34% of the population demonstrating positive reactions at titers of 1:128 or greater.     

Parasites of man in remote areas of Central and South Sulawesi, Indonesia

A biomedical survey was conducted in 10 villages in remote, high mountain valleys of Central and South Sulawesi, Indonesia to learn whether Oriental schistosomiasis was endemic and to determine the prevalences of other intestinal parasites, malaria and filariasis in those areas. Although persons with Oriental schistosomiasis were found in three villages of South Sulawesi, follow-up inquiries revealed that these had recently migrated from a known schistosomiasis area in Central Sulawesi. Other intestinal parasites diagnosed were Ascaris lumbricoides (14%), Trichuris trichiura (7%), hookworm (68%), Entamoeba histolytica (3%), Entamoeba coli (17%), and Giardia lamblia (5%). Enterobius vermicularis, Strongyloides stercoralis, Trichostrongylus sp., Physaloptera sp., Diphyllobothrium sp. heterophyid, echinostome and dicrocoelid-like termatodes, Endolimax nana and Chilomastix mesnili were detected infrequently. Malaria parasitemias due to Plasmodium falciparum, P. vivax and P. malariae were detected in 4% of the sampled populations, Malayan filariasis was diagnosed in 21% of the subjects examined.     

2011-2018年山东省淄博市"三热"病人疟原虫血片质量分析

目的　分析山东省淄博市“三热”病人疟原虫血片质量,为制订和调整该市消除疟疾后监测策略和措施提供科学依据。方法　对2011—2018年淄博市市级镜检站复核的全部“三热”病人疟原虫阴性血片和辖区内全部阳性血片进行复核,对血片制作、染色、清洁度以及复核结果进行分析。结果　2011—2018年淄博市市级镜检站共复核疟原虫阴性血片2 141张,阳性血片39张。阴性血片制片合格率为99.44%,染色合格率为97.62%,清洁度合格率为93.65%,复核一致率为100%,未发现漏检;复核阳性血片39张,血片制片合格率为46.15%,染色合格率为61.54%,清洁度合格率为76.92%,复核一致率为97.44%,其中虫种分型错误1张。淄博市各区（县）血片制作合格率和染色合格率差异均有统计学意义（P值均 ＜ 0.05）,血片清洁度合格率差异无统计学意义（[χ2] = 13.72,P > 0.05）;2011—2018年淄博市各年度血片制作、染色和清洁度合格率差异均有统计学意义（P值均＜ 0.05）。结论　淄博市各区（县）血片质量较高,但市级血片质量有待提高。今后应进一步加强基层疟原虫镜检培训力度和血涂片质量控制,促进血片质量不断提高,以保证疟疾消除后监测阶段疟原虫镜检能力     

Interpreteation of immunochromatographic tests with HRP-2 antigen in children under 5 years in an area of high risk of malaria transmission in Papua New Guinea

The immunochromatographic tests with HRP-2 antigen (histidine-rich protein) Vision Biotech Pf Rapid Malaria Test was performed in 291 children under 5 years presenting fever or history of fever (malaria presumptive cases) admitted to Children Out-Patient Department of the Modilon Hospital in Madang, in a high malaria risk area of Papua New Guinea. The results of the tests were compared to the results of the parasitic examination of the peripheral blood with light microscopy (thick and thin smears). The HRP-2 test showed very high sensitivity (95.4%) and specificity (94.1%) for Plasmodiumfalciparum parasitaemia and none or very low sensitivity and specificity for other malaria species. The HRP-2 test detected both asexual and sexual stages of the Plasmodium falciparum parasites. The test did not show significant changes in detection of different levels of parasitaemia. These findings enable to conclude that the HRP-2 immunochromatographic assay can be very helpful to diagnose Plasmodium falciparum malaria when microscopy examination is not available, but as qualitative tests can be difficult for interpretation especially in high malaria risk areas. Therefore it can require re-examination of blood with microscopy to confirm species and development stages of Plasmodium spp. and to assess parasite load.     

我国广西食蟹猴养殖场2种血液寄生原虫感染调查

目的 目的 调查我国广西壮族自治区某食蟹猴养殖场血液寄生原虫感染状况, 为人体血液寄生原虫的防控提供科 学依据。方法 方法 采集广西壮族自治区南宁市某食蟹猴养殖场猴血液样本993份, 全部制作FTA卡样本, 涂制薄血膜550 份。将样本混合, 以巢式PCR及普通PCR方法分别检测FTA卡保存的猴血样本中巴贝虫以及疟原虫。检测阳性组再分 别进行单个样本检测, 阳性样本对应的薄血膜进行姬姆萨染色后再镜检。 结果 结果 经巢式PCR检测, 田鼠巴贝虫检出阳 性率为6.95% （69/993）; 仅1例经PCR检出猪尾猴疟原虫阳性。22份PCR检测巴贝虫阳性的血液样本经染色镜检, 共16 份检出巴贝虫, 其显微镜下观察到红细胞内有环状体, 无疟色素。结论 结论 我国广西地区食蟹猴的田鼠巴贝虫感染率较 高, 其可能在传播中起保虫宿主的作用; 在筛查田鼠巴贝虫低密度感染时, 巢式PCR方法敏感性较高。     

Natural Plasmodium infections in Brazilian wild monkeys: reservoirs for human infections?

Four hundred and forty-eight samples of total blood from wild monkeys living in areas where human autochthonous malaria cases have been reported were screened for the presence of Plasmodium using microscopy and PCR analysis. Samples came from the following distinct ecological areas of Brazil: Atlantic forest (N=140), semideciduous Atlantic forest (N=257) and Cerrado (a savannah-like habitat) (N=51). Thick and thin blood smears of each specimen were examined and Plasmodium infection was screened by multiplex polymerase chain reaction (multiplex PCR). The frequency of Plasmodium infections detected by PCR in Alouatta guariba clamitans in the S?o Paulo Atlantic forest was 11.3% or 8/71 (5.6% for Plasmodium malariae and 5.6% for Plasmodium vivax) and one specimen was positive for Plasmodium falciparum (1.4%); Callithrix sp. (N=30) and Cebus apella (N=39) specimens were negative by PCR tests. Microscopy analysis was negative for all specimens from the Atlantic forest. The positivity rate for Alouatta caraya from semideciduous Atlantic forest was 6.8% (16/235) in the PCR tests (5.5, 0.8 and 0.4% for P. malariae, P. falciparum and P. vivax, respectively), while C. apella specimens were negative. Parasitological examination of the samples using thick smears revealed Plasmodium sp. infections in only seven specimens, which had few parasites (3.0%). Monkeys from the Cerrado (a savannah-like habitat) (42 specimens of A. caraya, 5 of Callithrix jacchus and 4 of C. apella) were negative in both tests. The parasitological prevalence of P. vivax and P. malariae in wild monkeys from Atlantic forest and semideciduous Atlantic forest and the finding of a positive result for P. falciparum in Alouatta from both types of forest support the hypothesis that monkeys belonging to this genus could be a potential reservoir. Furthermore, these findings raise the question of the relationship between simian and autochthonous human malaria in extra-Amazonian regions.     

Outpatient upper respiratory tract viral infections in children with malaria symptoms in Western Kenya

A cross-sectional study was performed in children 5 through 10 years of age presenting to outpatient clinics in Nyanza Province, Kenya, in which nasal swab and blood specimens were collected during the high malaria transmission season. Patients presenting with malaria-like symptoms within 4 days of fever onset were enrolled in the study. Plasmodium parasitemia was determined by blood smear microscopy. Nasal swabs were screened for a panel of respiratory viruses by polymerase chain reaction. Influenza A, rhinoviruses, and other respiratory viruses were detected in 18%, 26%, and 12% of 197 specimens, respectively. Four of 36 patients with influenza A had a positive malaria blood slide, compared with 20 of 52 patients with rhinovirus. A significant burden of disease caused by influenza A in febrile children during the study period was observed, highlighting the need for further research into the burden of influenza disease in regions where malaria is holoendemic.     

Performance of a histidine-rich protein 2 rapid diagnostic test, Paracheck Pf®, for detection of malaria infections in Ugandan pregnant women

Improved laboratory diagnosis is critical to reduce the burden of malaria in pregnancy. Peripheral blood smears appear less sensitive than Plasmodium falciparum histidine-rich protein 2-based rapid diagnostic tests (RDTs) for placental malaria infections in studies conducted at delivery. In this study, 81 women in Uganda in the second or third trimester of pregnancy were followed-up until delivery. At each visit, peripheral blood was tested by blood smear, RDT, and nested species-specific polymerase chain reaction (PCR). Sensitivity and specificity of the tests was calculated with PCR, which detected 22 infections of P. falciparum, as the gold standard. The sensitivity and specificity of blood smears were 36.4% (95% confidence interval [CI] = 18.0-59.2%) and 99.6% (95% CI = 97.7-100%), respectively. The corresponding values for RDT were 31.8% (95% CI = 14.7-54.9%) and 100% (95% CI = 98.3-100%). The RDTs could replace blood smears for diagnosis of malaria in pregnancy by virtue of their relative ease of use. Field-based sensitive tests for malaria in pregnancy are urgently needed.     

Heightened transmission of stable malaria in an isolated population in the highlands of Irian Jaya, Indonesia.

Malaria at an elevation of 1,500 meters is uncommon and is usually unstable when it occurs. To confirm reports of a recent increase in transmission of stable malaria in the Oksibil Valley, which is at an elevation of 1,250-1,500 meters in the Jayawijaya Mountains of Irian Jaya, Indonesia, five malariometric surveys were conducted in four villages between May 1990 and July 1991. A total of 3,380 blood smears, representative of 1,949 persons, was examined. Prevalence rates over the survey period were consistent in each of the four villages, averaging 10% for infants, 50% for children 1-4 years of age, 35% for those 5-9 years old, 28% for those 10-14 years old, and 16% for adults (greater than 15 years old). The spleen rate for the those less than five years old was 96%, with an average enlarged spleen score of 2.32. Plasmodium falciparum accounted for 55% of the infections in the valley, but P. vivax was the predominant species in those less than 10 years old. In the village of Kutdol at an elevation of 1,500 meters, P. malariae was identified in 43% of the positive smears. Four cases were diagnosed as P. ovale. Infection with P. falciparum without obvious clinical symptoms was common in both adults and children. Entomologic and epidemiologic data suggested that the recent upsurge in transmission coincided with the replacement of traditional village huts with the more modern social housing. This replacement required the extensive construction of drainage ditches, which inadvertently also served as additional vector breeding sites. We suspect that this manipulation of the environment, in an effort to improve the quality of life, created conditions conductive for heightened transmission of stable 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.     

3种检测方法在中缅边境疟疾无症状感染者筛查中的比较

目的比较3种不同检测方法对疟疾无症状感染者的检出能力,并了解中缅边境地区的疟疾无症状感染水平。方法2014年7月在中缅边境地区云南省盈江县选择那邦镇、支那乡和缅甸拉咱安置点等3个调查点,采集调查对象血样,制作厚薄血膜和滤纸血标本,分别采用显微镜观察、荧光定量PCR和超敏PCR检测疟原虫感染情况。结果共采集387份血样,显微镜观察检出6例无症状感染者(间日疟5例、恶性疟1例),感染检出率为1.6%;荧光定量PCR检出13例无症状感染者(间日疟12例、恶性疟1例),感染检出率为3.4%;超敏PCR检出38例无症状感染者(间日疟29例、恶性疟9例),感染检出率为9.8%。以显微镜观察为疟原虫感染诊断的金标准,荧光定量PCR检测无症状感染者的灵敏度为100%,特异性为98.2%;超敏PCR检测无症状感染者的灵敏度为100%,特异性91.6%。超敏PCR结果显示,那邦镇的无症状感染检出率最高,为17.1%(22/129),其次为缅甸拉咱难民安置点,为10.0%(11/110),支那乡最低,为3.4%(5/148),3个调查点的感染检出率差异有统计学意义(P<0.05)。检出虫种以间日疟原虫为主,占76.3%,恶性疟原虫占23.7%;女性无症状感染检出率为10.7%(23/215),高于男性的8.7%(15/172),两者差异无统计学意义(P>0.05)。不同年龄组以15~29岁的无症状感染检出率最高,为17.5%(10/57),各年龄组间差异无统计学意义(P>0.05)。结论超敏PCR对疟疾无症状感染者的检出率高于荧光定量PCR和显微镜观察。中缅边境地区人群中存在一定比例的疟疾无症状感染者。     

Plasmodium vivax: detection of blood parasites using fluorochrome labelled monoclonal antibodies

A monoclonal antibody (MoAb) 2C6111 specific for Plasmodium vivax erythrocytic stages was shown to detect parasitized erythrocytes in blood samples collected in the field. This MoAb binds to the mature trophozoite, schizont and gametes of P. vivax and upon examination of 43 wild isolates no evidence of polymorphism was found. To search for P. vivax parasites in human blood a MoAb immunofluorescent test (MoAb-IFT) was developed. The assay is based on the ability of fluorescein isothiocyanate labelled MoAb 2C6111 to combine with parasitized erythrocytes on thin blood smears. A preliminary field trial was carried out in Venezuela to determine the usefulness of MoAb-IFT for the specific diagnosis of P. vivax malaria. Blood samples collected from malarious and non-malarious individuals were examined both by standard microscopy of Giemsa stained thick blood smears (G-TS) and MoAb-IFT. The latter was specific and gave a 100% correlation with G-TS. Sensitivity was close to that usually achieved with Giemsa stained blood films.,     

Prevalence of intestinal parasite infections among patients in local public hospitals of Hail,Northwestern Saudi Arabia

Objective:To evaluate the prevalence of intestinal parasites among patients in Hail,Northwestern Saudi Arabia.Methods:Stool samples were collected from 130 patients(69females and 61 males) in Hail General Hospital.Each sample was examined by direct wet mount microscopic examination using both normal saline and Lugol's iodine preparation and concentration techniques using salt and formol-ether solutions.Permanent stained smears were performed for intestinal coccidian using modified Ziehl-Neelsen technique.Results:The overall prevalence of intestinal parasitic infection was 45.38%(59 cases).Forty-four(33.84%)were found to be infected with one or more intestinal protozoa.5(3.84%) were infected with helminthes and 10(7.69%) had mixed infection with both helminthes and protozoa.The most common intestinal helminth detected was Ancyloxtoma duvdenale(n=5.3.84%),followed by Ascaris lumlmcnidex.Taenia sp.and Trichuris trichiura(n=2 for each species,1.5%).For intestinal protozoa,the coccidian Cryptosporidium parvum(n=25,19.23%) was the most common followed by Entamoeba histolytica/dispur(n=21,16.15%),Giurdia lamblia(n=15,11.54%),Entamoeba coli(n=5.3.85%) and Blastocysts hominis(n=3,2.30%).The prevalence of intestinal parasitic infections in females was significantly higher than in males(P0.05).Conclusions:This is the first study highlighting that intestinal parasites are still an important public health problem in Northwestern Saudi Arabia Therefore,health education would be the best way to prevent from intestinal parasite infections which are mainly food borne diseases.     

Potential vectors of malaria and their different susceptibility to Plasmodium falciparum and Plasmodium vivax in northern Brazil identified by immunoassay

During the period from May 1983 to July 1985 we conducted an epidemiological study to determine potential vectors of malaria in 6 districts in the state of Pará in northern Brazil. The examination of random human blood smears, prepared at the time of mosquito capture, indicated overall human infection rates of 16.7% and 10.9% for Plasmodium falciparum and P. vivax, respectively. Two immunoassays, the immunoradiometric assay (IRMA) and the enzyme-linked immunosorbent assay (ELISA), based on the use of species-specific antisporozoite monoclonal antibodies, were used to analyze a total of 9,040 field-collected Anopheles mosquitoes for plasmodial infection. P. falciparum sporozoite antigen was detected in A. darlingi at rates varying from 2.7% to 4.2%, and in small numbers of A. oswaldoi collected in 1 of the districts. In contrast, sporozoite antigen of P. vivax was found in A. darlingi, A. triannulatus, A. nuneztovari, and A. albitarsis at rates ranging from 0.9% to 12.0%. By dissection, sporozoites were found in the salivary glands of these same 4 species at rates ranging from 0.8% to 2.2%. The latter 3 species had not previously been implicated as malaria vectors of any significance in northern Brazil.     

从Giemsa染色的血膜中扩增间日疟原虫DNA方法探讨

目的 建立从Giemsa染色的血膜中提取疟原虫DNA的方法。 方法 分别采用Na₂HPO₄法和Chelex-100离子交换法，经过反复优化，提取血膜中的DNA，进行套式PCR扩增鉴定PvMSP-1等位基因型。 结果 用Na₂HPO₄法和Chelex-100离子交换法分别提取40张不同类型的间日疟原虫阳性血膜DNA，未染色的厚血膜全部扩增出目的基因条带，而染色的薄血膜未能扩增出目的基因条带。两种方法均可检测红细胞间日疟原虫感染率≥0.01％的血涂片。 结论 从多年保存的标准血膜中提取疟原虫DNA进行基因型鉴别是可行的。     

山东省首例输入性三日疟病例报告

本文报告山东省首例输入性三日疟,患者曾在非洲安哥拉务工4年,回国后2d（2013年1月25日）因发热、出汗、头痛、乏力而就诊,疟原虫血涂片镜检阴性。50d后（2013年3月17日）再次因发热、全身乏力就诊,血涂片镜检发现疟原虫,诊断为间日疟,经氯喹／伯氨喹8d治疗后痊愈,随访3个月未见再燃。省级复核血涂片发现典型的三日疟多期原虫,经PCR基因检测,确证为三日疟。提示应加强疟防专业人员诊治罕见三日疟、卵形疟的技能培训,以减少误诊、误治。     

Genetic diversity of Plasmodium vivax and Plasmodium falciparum in Kohat District, Pakistan

Malaria is one of the serious diseases threatening human health in Pakistan and contributes to a large proportion of the total malaria deaths in South Asia. However, little is known about the nature and extent of genetic diversity of the malarial parasites circulating in Pakistan. This study was designed to assess the infection status of Plasmodium and the genetic diversity of Plasmodium vivax and Plasmodium falciparum by analyzing msp-3α, msp-3β and msp-1, msp-2 genes respectively using allele specific nested PCR and RFLP assays. For this purpose, 130 field isolates were collected from the individuals who exhibited clinical symptoms associated with malaria in the Kohat region of Khyber Pakhtoonkhwa (KPK), Pakistan. Among 130 blood samples collected, P. vivax was detected in 105/130 (80.8%) and P. falciparum in 21/130 (16.2%). Mixed infections with both parasites were detected in 4/130 (3%) of the isolates. A large number of distinguishable alleles were found for msp genetic markers: 10 alleles for msp-3α and seven for msp-3β with one mixed infection in case of msp-3β. The genotyping of P. falciparum showed that K1+MAD20 mixed genotype was dominant in msp-1 and FC27 in msp-2. The results collectively suggest that P. vivax and P. falciparum populations in this region are highly polymorphic and mixed infections are prevalent.     

Malaria epidemiology along Indo-Bangladesh border in Tripura State, India

Malaria epidemiological surveys were conducted in 16 villages along the Indo-Bangladesh border in Tripura, northeastern India. Insecticide resistance among malaria vectors and chloroquine resistance in the parasite were also studied along with monitoring of vector density using light traps. The epidemiological data indicated that malaria incidence was highest during June-July and lowest during November. Examination of blood smears collected through door to door surveys indicated slide positivity rate (SPR) of 25.2% and that Plasmodium falciparum was the predominant parasite (slide falciparum rate of 22.3%). The incidence rates of falciparum malaria varied significantly among the age groups (p<0.001) and 2-4 year olds were the most affected. Major malaria vectors recorded in light trap collections were An. dirus, An. minimus and An. philippinensis/nivipes. Chloroquine resistance studies indicated that treatment failure occurred in 35% of the cases and hence the use of artesunate combination therapy (ACT) was recommended for treatment of malaria in the area.     

单克隆抗体夹心斑点免疫金银染色法诊断恶性症的...

In this report, the blood samples from 30 falciparum malaria patients with parasitemia 0.015-0.58% and the blood samples from 30 healthy persons were examined by monoclonal antibody (McAb) sandwich dot-immunogold silver staining assay (Dot-IGSSA). When the McAb 11G5, 13A2 and 13A1 were used for sandwich Dot-IGSSA with McAb 14D9 labeled with colloidal gold respectively, the 0.0001% of parasitemia could be detected and the McAb 11G5, 13A1 and 14D9 labeled with colloidal gold could also be used to detect the antigens of asexual blood stages of Yunnan and Anhui isolates of Plasmodium falciparum cultured in vitro. These McAbs did not cross-react with the antigens of Plasmodium knowlesi and Plasmodium berghei, however, the McAbs 13A1 and 14D9 weakly cross-reacted with the antigens of Plasmodium cynomolgi and the antigens in the infected blood samples from patients with vivax malaria.