The phenomenon of the delayed initial attack of tertian malaria]

From 1986 to 1990 we have treated 215 patients with falciparum malaria. In 8 patients (4%) who had not returned to any malarial area, malaria attacks recurred after 6-20 weeks. Curiously these were now caused by different species: Plasmodium vivax (4 patients) and P. ovale (4 patients). After proper management of malignant tertian malaria caused by P. falciparum, patients are considered cured, provided the treatment has been in accordance with the resistance pattern of the parasite in the country of origin. Yet, in a small number of patients attacks of malaria recur after different time intervals. The explanation of this seemingly paradoxical phenomenon is that these were delayed primary attacks of benign tertian malaria rather than recrudescences of malignant tertian malaria. Consequently the patients must have been infected by two different species of malaria at a time. In P. vivax and P. ovale hypnozoites occur (notably absent in P. falciparum), dormant stages in the liver that are not susceptible to the antimalarials in use for the eradication or prophylaxis of the blood stages which cause the acute attacks of malaria. After a variable amount of time the blood is then (re)invaded and the patient suffers a delayed primary attack or a relapse. Physicians should be aware that definite cure of malignant tertian malaria does not prevent future attacks of benign tertian malaria. They should inform their patients accordingly.     

Sulfadoxine-pyrimethamine plus artesunate compared with chloroquine for the treatment of vivax malaria in areas co-endemic for Plasmodium falciparum and P. vivax: a randomised non-inferiority trial in eastern Afghanistan

Chloroquine (CQ) is an effective treatment of choice for vivax malaria in most settings, but with the spread of CQ-resistant Plasmodium falciparum, many countries now use artemisinin-based combination therapy for treatment of falciparum malaria. In areas co-endemic for falciparum and vivax malaria incorrect differential diagnosis is always a risk. In Afghanistan the adoption of sulfadoxine-pyrimethamine plus artesunate (SP+AS) as first-line falciparum treatment raises the prospect of a significant proportion of vivax malaria being misdiagnosed and treated with the combination. SP is considered to have limited efficacy against vivax malaria, and the efficacy of SP+AS against Plasmodium vivax has not been established in areas that are using SP+AS. A randomised, non-inferiority trial comparing SP+AS with CQ monotherapy was undertaken on 190 vivax malaria patients in eastern Afghanistan. Standard WHO procedures for in vivo evaluation of antimalarial drugs were followed. A total of 180 individuals completed the trial to day 42. Using a per protocol analysis, both regimens resulted in > or =96% treatment success at 28 d, but significantly more cases failed in the CQ arm (46%) than in the SP+AS arm (24%) by day 42. In areas where vivax infections might be misdiagnosed as falciparum infections and treated with SP+AS, patient management would be as good, or better than, with the standard CQ treatment.     

Clinical and epidemiological profiles of severe malaria in children from Delhi, India

Plasmodium vivax is traditionally known to cause benign tertian malaria, although recent reports suggest that P. vivax can also cause severe life-threatening disease analogous to severe infection due to P. falciparum. There are limited published data on the clinical and epidemiological profiles of children suffering from 'severe malaria' in an urban setting of India. To assess the clinical and epidemiological profiles of children with severe malaria, a prospective study was carried out during June 2008-December 2008 in the Department of Pediatrics, Guru Teg Bahadur Hospital, a tertiary hospital located in East Delhi, India. Data on children aged < or = 12 years, diagnosed with severe malaria, were analyzed for their demographic, clinical and laboratory parameters. All patients were categorized and treated as per the guidelines of the World Health Organization. In total, 1,680 children were screened for malaria at the paediatric outpatient and casualty facilities of the hospital. Thirty-eight children tested positive for malaria on peripheral smear examination (2.26% slide positivity rate). Of these, 27 (71%) were admitted and categorized as severe malaria as per the definition of the WHO while another 11 (29%) received treatment on outpatient basis. Most (24/27; 88.8%) cases of severe malaria (n=27) were infected with P. vivax. Among the cases of severe malaria caused by Plasmodium vivax (n=24), 12 (50%) presented with altered sensorium (cerebral malaria), seven (29.1%) had severe anaemia (haemoglobin <5 g/dL), and 17 (70.8%) had thrombocytopaenia, of which two had spontaneous bleeding (epistaxis). Cases of severe vivax malaria are clinically indistinguishable from severe falciparum malaria. Our study demonstrated that majority (88.8%) of severe malaria cases in children from Delhi and adjoining districts of Uttar Pradesh were due to P. vivax-associated infection. P. vivax should, thus, be regarded as an important causative agent for severe malaria in children.     

Retinal haemorrhage in vivax malaria

Retinal haemorrhage is often observed in patients with Plasmodium falciparum, especially when combined with cerebral malaria. However, few cases of retinopathy have been reported in P. vivax malaria. Benign tertian malaria has re-emerged among soldiers in the South Korean demilitarized zone since 1993. We report an indigenous case of retinal haemorrhage caused by P. vivax and review the relevant literature.     

Induced malaria and antibody titres in acute infections and in blood donors in Kuwait

Concurrent with the increase in the number of imported cases of malaria into non-endemic Kuwait during the past 5 years, induced infections have been identified for the first time. We report 10 such cases over a 4-year-period. Of 8 transfusion-induced infections, 4 were due to Plasmodium falciparum and 4 to P. vivax. The mean incubation period for P. falciparum patients was 13 d and for P. vivax, 17 d. An accidental syringe-needle transmission and a congenital infection were due to P. falciparum and P. vivax respectively. Malarial antibody levels were assayed on commercially-available cultured P. falciparum schizonts by the indirect fluorescent antibody (IFA) test. To establish a base line, the sera of patients with blood film-confirmed P. falciparum and P. vivax were assayed. 96% of the P. falciparum sera were positive, the geometric mean titre (GMT) being 10,280. However, all sera from P. vivax patients were reactive but the GMT was lower at 505. 28% of sera from Kuwaitis and 45% of sera of a consecutive group of blood donors were also reactive, the respective GMTs being 38 and 51. The risk of transfusion malaria was calculated as 79 per million units drawn, an unacceptably high figure for a non-endemic country. We suggest a revised blood donor policy.     

Therapeutic response of multidrug-resistant Plasmodium falciparum and P. vivax to chloroquine and sulfadoxine-pyrimethamine in southern Papua, Indonesia

To determine the level of antimalarial drug resistance in southern Papua, Indonesia, we assessed the therapeutic efficacy of chloroquine plus sulfadoxine-pyrimethamine (CQ+SP) for Plasmodium falciparum infections as well as CQ monotherapy for P. vivax infections. Patients with P. falciparum failing therapy were re-treated with unsupervised quinine+/-doxycycline therapy and those with P. vivax with either unsupervised quinine+/-doxycycline or amodiaquine. In total, 143 patients were enrolled in the study (103 treated with CQ+SP and 40 with CQ). Early treatment failures occurred in four patients (4%) with P. falciparum and six patients (15%) with P. vivax. The failure rate by Day 28 for P. vivax was 65% (95% CI 49-81). After PCR correction for re-infections, the Day 42 recrudescence rate for P. falciparum infections was 48% (95% CI 31-65). Re-treatment with unsupervised quinine+/-doxycycline resulted in further recurrence of malaria in 48% (95% CI 31-65) of P. falciparum infections and 70% (95% CI 37-100) of P. vivax infections. Eleven patients with recurrent P. vivax were re-treated with amodiaquine; there were no early or late treatment failures. In southern Papua, a high prevalence of drug resistance of P. falciparum and P. vivax exists both to first- and second-line therapies. Preliminary data indicate that amodiaquine retains superior efficacy compared with CQ for CQ-resistant P. vivax.     

Malaria surveillance--United States, 1998.

PROBLEM/CONDITION: Human malaria is caused by one or more of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). The protozoa are transmitted by the bite of an infective female Anopheles species mosquito. The majority of malaria infections in the United States occur among persons who have traveled to areas with endemic transmission. Cases occasionally occur that are acquired through exposure to infected blood products, by congenital transmission, or by local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers. REPORTING PERIOD: Cases with an onset of symptoms during 1998. DESCRIPTION OF SYSTEM: Malaria cases confirmed by blood smear are reported to local and state health departments by health-care providers and laboratory staff members. Case investigations are conducted by local and state health departments, and reports are sent to CDC through the National Malaria Surveillance System (NMSS). This report uses NMSS data. RESULTS: CDC received reports of 1,227 cases of malaria with onsets of symptoms in 1998, among persons in the United States and its territories. This number represents a decrease of 20.5% from the 1,544 cases reported during 1997. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 42.8%, 37.8%, 3.5%, and 2.1% of cases, respectively. More than one species was present in seven patients (0.6% of total). The infecting species was not determined in 162 (13.2%) cases. Compared with reported cases in 1997, reported malaria cases acquired in Africa increased by 1.3% (n = 706); those acquired in Asia decreased by 52.1% (n = 239); and those acquired in the Americas decreased by 6.5% (n = 229). Of 636 U.S. civilians who acquired malaria abroad, 126 (19.8%) reportedly had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Five persons became infected in the United States. One case was congenitally acquired; one was acquired by blood transfusion; and three were isolated cases that could not be epidemiologically linked to another case. Four deaths were attributed to malaria. INTERPRETATION: The 20.5% decrease in malaria cases during 1998 compared with 1997 resulted primarily from decreases in P. vivax cases acquired in Asia among non-U.S. civilians. This decrease could have resulted from local changes in disease transmission, decreased immigration from the region, decreased travel to the region, incomplete reporting from state and local health departments, or increased use of effective antimalarial chemoprophylaxis. In a majority of reported cases, U.S. civilians who acquired infection abroad had not taken an appropriate chemoprophylaxis regimen for the country where they acquired malaria. PUBLIC HEALTH ACTIONS TAKEN: Additional information was obtained from state and local health departments and clinics concerning the four fatal cases and the five infections acquired in the United States. Persons traveling to a malarious area should take a recommended chemoprophylaxis regimen and use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and subsequently develops fever or influenza-like symptoms should seek medical care immediately; the investigation should include a blood smear for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Current recommendations concerning prevention and treatment of malaria can be obtained from CDC.     

Therapeutic responses to antibacterial drugs in vivax malaria.

Some antibacterial drugs have antimalarial activity that can be exploited for the prevention or treatment of malaria. Monotherapy with tetracycline, doxycycline, clindamycin or azithromycin was assessed in 1995-98 in 92 adult patients in Thailand with Plasmodium vivax malaria. All patients recovered following treatment and the early therapeutic responses were similar among the 4 groups. The overall median fever clearance time was 57 h and the mean (SD) overall time to parasite clearance was 134 (48) h. Of 66 patients who completed a 28-day follow-up, reappearances of vivax infection occurred in 27 patients (41%) from all groups; delayed appearances of falciparum malaria occurred in 6 patients (9%), only from the azithromycin group. The overall mean (SD) time to reappearance of P. vivax was 23 (5) days and time taken for detection of falciparum malaria was 13 (4) days after starting treatment for vivax malaria. The 28-day cumulative cure rates of clindamycin (n = 12), tetracycline (n = 18) and doxycycline (n = 18) groups were similar (P > or = 0.14) and all were significantly higher compared to the azithromycin group (n = 18; P < or = 0.04). The intervals until vivax reappearance were also significantly shorter in the azithromycin group [mean (SD) = 21 (6) vs 25 (3) days, P < 0.05] suggesting that some of these were recrudescences. The apparent success rate (no subsequent appearances of either vivax or falciparum infection) was significantly lower for the azithromycin group (11%) compared to the other groups (34-78%; P < 0.01). In current antibacterial treatment regimens, short-course azithromycin has inferior antimalarial activity compared to clindamycin or the tetracyclines.     

Malaria in Poland in 2001

In 2001, 27 malaria cases were registered in Poland. All of them were imported, mainly from Africa (18 cases). Plasmodium vivax infection was confirmed in eleven cases, P. falciparum--in ten, P. falciparum/P. vivax--in four, P. malariae--in one and Plasmodium sp.--in one. Among 27 malaria cases 17 were men and 16 in 20-49 years old group. Twelve persons travelled abroad as tourists, five--as missionaries, three--in the connection with their job. In 2001 malaria deaths were not notified.     

Demonstration by the polymerase chain reaction of mixed Plasmodium falciparum and P. vivax infections undetected by conventional microscopy.

Mixed malaria infections (Plasmodium falciparum and P. vivax) are suspected to occur at a greater frequency than is detected by conventional light microscopy. To determine this frequency we carried out a prospective 'blinded' comparison of diagnosis by conventional light microscopy and enzymatic amplification of the circumsporozoite gene extracted from dried spotted blood samples. Patients were previously healthy, active duty Thai soldiers assigned to a malaria risk area presenting with malaria. Microscopy (oil immersion objective at 1000 x magnification) involved examination of Giemsa-stained thick and thin blood films by an experienced microscopist. Whole blood samples (25 microliters) dried on filter paper were used for species-specific parasite deoxyribonucleic acid (DNA) amplification by the polymerase chain reaction (PCR) and hybridization with radiolabelled P. falciparum and P. vivax probes. Of 137 consecutive cases of malaria studied, 9% (3/32) of microscopically diagnosed P. falciparum infections and 5% (5/104) of microscopically diagnosed P. vivax infections were found to be mixed by the PCR/DNA probe systems, while 1 case was diagnosed as mixed by both microscopy and PCR. The possibility that malaria patients may have undetected mixed infections should be kept in mind because of the specific therapy required both for P. falciparum and for radical cure of P. vivax.     

Susceptibility to vivax malaria in Ethiopia.

Plasmodium vivax prevalence rates for Nilotic and Hamitic-Semitic residents of an Ethiopian town were compared. Over a ten-year period, 8,316 blood films from Nilotes were examined and 59 P. vivax infections (0.7%) were diagnosed. In 1,630 films from Hamito-Semites, 75 probable P. vivax infections (4.6%) were found. The problem of morphological differentiation between P. vivax and P. ovale was evaded by combining the two diagnoses. P. vivax/ovale infection rates for Hamitic-Semitic subjects were higher than for Nilotic subjects in all age groups. It was concluded that the two populations are inately different in susceptibility to patient infection with vivax malaria.     

Diagnosis of Plasmodium vivax malaria using a specific deoxyribonucleic acid probe

A deoxyribonucleic acid (DNA) probe which specifically distinguishes Plasmodium vivax from P. falciparum malaria has been derived from a P. vivax genomic DNA library. This probe, VPL101, consists of 3.2 kilobase pairs and does not hybridize with up to 6 micrograms of human or P. falciparum DNA. VPL101 contains at least two copies of a 205 base pair repeat sequence. The subcloned repeat probe, VPL101/5, reacted with 73 of 76 microscopically diagnosed P. vivax samples but not with any of 17 human DNA samples or any of 8 P. falciparum DNA samples from cultured parasites. It was possible to detect P. vivax in mixed infections in which only P. falciparum parasites were identifiable by microscopy. This P. vivax DNA probe provides a useful epidemiological tool for malaria control programmes.     

Malaria surveillance--United States, 1993.

PROBLEM/CONDITION: Malaria is caused by infection with one of four species of Plasmodium (P. falciparum, P. vivax, P. ovale, and P. malariae), which are transmitted by the bite of an infective female Anopheles sp. mosquito. Most malaria cases in the United States occur among persons who have traveled to areas (i.e., other countries) in which disease transmission is ongoing. However, cases are transmitted occasionally through exposure to infected blood products, by congenital transmission, or by local mosquito-borne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations. REPORTING PERIOD COVERED: Cases with onset of illness during 1993. DESCRIPTION OF SYSTEM: Malaria cases confirmed by blood smear are reported to local and/or state health departments by health-care providers and/or laboratories. Case investigations are conducted by local and/or state health departments, and the reports are transmitted to CDC. RESULTS: CDC received reports of 1,275 cases of malaria in persons in the United States and its territories who had onset of symptoms during 1993; this number represented a 40% increase over the 910 malaria cases reported for 1992. P. vivax, P. falciparum, P. ovale, and P. malariae were identified in 52%, 36%, 4%, and 3% of cases, respectively. The species was not determined in the remaining 5% of cases. The 278 malaria cases in U.S. military personnel represented the largest number of such cases since 1972; 234 of these cases were diagnosed in persons returning from deployment in Somalia during Operation Restore Hope. In New York City, the number of reported cases increased from one in 1992 to 130 in 1993. The number of malaria cases acquired in Africa by U.S. civilians increased by 45% from 1992; of these, 34% had been acquired in Nigeria. The 45% increase primarily reflected cases reported by New York City. Of U.S. civilians who acquired malaria during travel, 75% had not used a chemoprophylactic regimen recommended by CDC for the area in which they had traveled. Eleven cases of malaria had been acquired in the United States: of these cases, five were congenital; three were induced; and three were cryptic, including two cases that were probably locally acquired mosquito-borne infections. Eight deaths were associated with malarial infection. INTERPRETATION: The increase in the reported number of malaria cases was attributed to a) the number of infections acquired during military deployment in Somalia and b) complete reporting for the first time of cases from New York City. ACTIONS TAKEN: Investigations were conducted to collect detailed information concerning the eight fatal cases and the 11 cases acquired in the United States. Malaria prevention guidelines were updated and disseminated to health-care providers. Persons who have a fever or influenza-like illness after returning from a malarious area should seek medical care, regardless of whether they took antimalarial chemoprophylaxis during their stay. The medical evaluation should include a blood smear examination for malaria. Malaria can be fatal if not diagnosed and treated rapidly. Recommendations concerning prevention and treatment of malaria can be obtained from CDC.     

Malaria--Great Exuma, Bahamas, May-June 2006

Malaria in humans is caused by four distinct protozoan species of the genus Plasmodium (P. falciparum, P. vivax, P. ovale, and P. malariae). These parasites are transmitted by the bite of an infective female Anopheles mosquito. In the Caribbean region, malaria has been eliminated from all islands except Hispaniola, the island consisting of Haiti and the Dominican Republic. Elimination of malaria elsewhere resulted from a combination of integrated control measures, socioeconomic development, and close public health surveillance. However, even Caribbean islands where malaria is no longer endemic remain at constant risk for reintroduction of the disease because of their tropical climate, presence of competent malaria vectors, and proximity to other countries where malaria is endemic. This susceptibility was underscored by the recent outbreak of malaria on the island of Great Exuma in the Bahamas; during May-June 2006, a total of 19 malaria cases were identified. Four of the cases, in travelers from North America and Europe, are described in this report; such cases of imported malaria can signal the presence of a malaria problem in the country visited and thus assist local health authorities in their investigations. On September 19, after 3 months with no report of new cases, CDC rescinded its previous recommendation that U.S.-based travelers take preventive doses of the antimalarial drug chloroquine before, during, and after travel to Great Exuma.     

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.     

Imported malaria in Kuwait

The number of imported malaria cases in Kuwait rose from 87 in 1980 to 504 in 1983, an increase of 579%. The continued resurgence of malaria in endemic zones, improved diagnostic techniques and a heightened awareness of imported malaria have contributed to the increase in the number of microscopically proved cases. Thick blood films fixed in acetone and stained in Giemsa proved a rapid method of diagnosis; species identification on the basis of a thin film on the same slide was performed with ease. Malaria was acquired in 38 countries. Most patients were young male adults. Most of the cases were due to Plasmodium vivax originating from India, although an increasing number of P. falciparum cases are also now being diagnosed from there. P. falciparum infections were evenly distributed throughout the year and most cases presented within 14 days of their arrival in the country. The highest number of P. vivax cases were diagnosed between May and October, when heat stress might have been a factor in precipitating a clinical attack of an infection previously acquired in the endemic zone. Attention is drawn to the importance of delayed attacks of P. vivax and, in semi-immunes, of P. falciparum. The time interval involved in establishing a history of "recent" travel in clinically suspected cases of malaria needs to be more clearly defined in each geographical area. Cases of induced malaria due to transfusion, accidental and congenital infections were identified. The fatality rate due to P. falciparum infections was low. In terms of the risk of renewed transmission, Kuwait may be considered a vulnerable area.     

Malaria prevalence and morbidity among children reporting at health facilities in Nouakchott, Mauritania

Although malaria has become a serious public health problem in Mauritania since the late 1990s, few documented data on its epidemiology exist. The objective of this study was to assess the morbidity of clinical malaria among children in Nouakchott. Three hundred and one febrile children, consulting at three health facilities of Nouakchott, were screened for malaria in 2009 (n=216) and 2010 (n=85). Plasmodium species identification and parasite density were determined by microscopic examination of Giemsa-stained thin and thick films and confirmed by rapid diagnostic test and nested PCR. Of 301 febrile children, 105 (34.9%) were malaria-positive by nested PCR and 87 (28.9%) by microscopy. Plasmodium vivax represented 97.1% (102/105) and P. falciparum accounted for 2.9% (3/105) of positive cases. All positive children under five years old were infected with P. vivax. The highest numbers of malaria positives were found during or shortly after the rainy season and the lowest during the dry season. Fifty-four of 105 (51.4%) malaria cases, all with P. vivax, had never travelled outside Nouakchott. Individuals belonging to the Moors ethnic group represented 97.0% of P. vivax cases. Results of the present study indicate that malaria is endemic in Nouakchott and that P. vivax is the principal causative agent. Regular surveillance is required to monitor malaria prevalence and incidence, and further measures are needed to counter the possible spread of malaria in the country.     

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.     

杭州市1990-2009前后十年疟疾流行病学特征比较分析

目的对杭州市达到基本消灭疟疾标准后,1990-1999年与2000-2009年前后十年疟疾疫情的流行特点进行比较分析,为制定今后的疟疾防治策略提供依据。方法对1990-2009年血检阳性确诊疟疾病例的个案调查资料进行统计分析,采用SPSS 11.5统计软件,采用χ2检验对1990-1999年和2000-2009年的流行特点进行比较分析,P<0.05为差异有统计学意义。结果 1990-2009年平均年发病率0.2/10万,1990-1999年疟疾发病呈高度散发,2000-2009年出现疟疾局部暴发疫情;前后十年疟疾病人在不同性别、职业及年龄组中的构成比差异均有统计学意义(P均<0.05);前后十年本地、外出感染、外来患者在构成上差异有统计学意义(χ2=47.74,P<0.05);2000-2009年本地病人发病高峰(8~10月份)明显滞后外来病人(6~9月份);1990-2009年疟疾病人627例,其中共检出间日疟598例,恶性疟29例,分别占95.37%和4.63%,前后十年间日疟和恶性疟构成比差异无统计学意义(χ2=3.54,P=0.06)。结论 2000-2009年大量外来病人的输入使杭州市疟疾发病总人数明显上升,出现局部暴发疫情,不断加强对来自高疟区流动人口的监测,提高医疗单位疟疾诊治和镜检能力,从源头上控制传染源,是今后杭州市疟疾防治工作的重点。     

Malaria in Aberdeen: an audit of 110 patients admitted between 1980-1991.

All 110 patients seen in North East Scotland after contracting malaria from foreign travel were treated in the Regional Infection Unit in Aberdeen. Those patients managed there from January 1980 to March 1991 are described. There were 54 episodes of Plasmodium falciparum malaria (49%) and 26 episodes (23%) of Plasmodium vivax malaria. The remainder had either mixed infection or were diagnosed as malaria on high clinical probability. The majority of the patients were male (80%) and under 40 years of age (84%). Most patients were either caucasians born in the UK (69%) or native Africans (23%) who were students recently arrived for further education or who had returned from visiting their country of origin for summer holidays. The British residents acquired infection either while on oil related business in West or Central Africa (46%) or after travelling on holiday (30%). The peak incidence of presentation was August and September. 93.5% of patients with falciparum malaria had returned or originated from Africa. 42% with vivax malaria had visited Africa and 27% Papua New Guinea. 70% had been prescribed antimalarial prophylaxis but less than half of these took their medication correctly. The majority of patients with falciparum malaria presented within two weeks of arrival in Britain while patients with vivax malaria presented at varying (but generally longer) intervals, 42% being diagnosed more than three months after exposure. Falciparum infection was more severe although there have been no deaths in the unit from malaria. Our experience seemed of interest and worth reporting because of the number of patients whose infection reflected travel related to the off shore oil industry, which is centred in Aberdeen.