Progress in malaria control in endemic areas

The international community is now making a serious effort to bring malaria under control. Funds for malaria control have become available on a scale not seen since the days of the eradication campaign 50 years ago. These new resources are being used largely to support a supply of artemisinin combination therapy to replace ineffective chloroquine and sulphadoxixne pyrimethamine for first line treatment of malaria and for the provision of long-lasting, insecticide treated bednets. There are early indications from several countries in Africa that this renewed effort at malaria control is beginning to have an effect but additional tools will probably be needed, including a highly effective vaccine, if the ultimate goal of malaria eradication is to be achieved.     

1996～1998年四川省不同疟区疟疾监测

经过多年的防治 ,四川省的疟疾发病人数逐年减少 ,已由 1990年的 39746人降至 1995年的 80 44人 ,减少79.76 % ,发病率由 3.7 下降至 1.0 以下。流行程度大大降低 ,疟区范围不断缩小 [1 ] ,全省疟疾流行县中已有半数以上达到了卫生部颁布的基本消灭疟疾标准。为了更准确地掌握四川省疟疾流行的动态和防治效果 ,指导全省疟疾防治工作 ,于 1996～ 1998年 ,按照疟疾流行程度及媒介类型等不同特点 ,对沐川县等 9个县进行了疟疾流行病学和媒介按蚊生物学监测。内容与方法1　监测县选择疟疾发病率 >5 的沐川县、名山县、宜宾县和发病率 <1 的岳…     

Behavior of people with respect to malaria in endemic areas with different levels of malaria transmission.

The present survey was carried out in two villages of the same malaria endemicity but different levels of transmission in Lamae District, Chumphon Province, southern Thailand with the aim to study whether behavior of people to malaria was similar or not. The total populations in low (village 11) and high (village 13) transmission areas were surveyed twice during low (February 1990) and high (June 1990) transmission periods. All subjects were interviewed by trained interviewers using a structured interview form. Among 410 and 614 people in villages 11 and 13, respectively, it was revealed that during the low transmission period behavior related to chemoprophylaxis and use of bed nets was similar in both villages, whereas risk behavior of night work was significantly higher in village 11 than village 13. This was likely due to their different principal occupations: farming of rubber plantation in village 11 and of coffee plantation in village 13. Concerning pattern of seeking malaria treatment, the malaria clinic and the district hospital were the common places attended by people in both villages. During the second survey in high transmission period, a cohort of 277 in village 11 and 430 in village 13 were available for follow up to study changes in their behavior between low and high transmission seasons. There were significant decrements related to night work and significant increments related to bed net use in both villages.     

Seroepidemiological studies of malaria in different endemic areas of Indonesia.

A total of 618 sera from inhabitants living in various endemic areas in Indonesia were examined for IgG against Plasmodium falciparum utilizing young trophozoites and mature schizonts as antigens by the method of ELISA and IFAT. In general, antibodies against trophozites (RESA) based on ELISA and antibodies against schizonts based on IFAT showed a correlation of malarial antibodies with the level of endemicity of the area examined. Anti-RESA antibody, detected either by ELISA or IFAT was more pronounced in the aparasitemic group compared to the parasitemic group. On the contrary, anti-schizont antibody measured by IFAT was more pronounced in the parasitemic group. Malarial antibody levels against the schizont-merozoite fraction of P. falciparum as assayed by ELISA appeared to develop more slowly compared to levels based on IFAT.     

海南省不同疟区疟疾纵向调查

万宁市南桥和五指山市毛阳历史上均属超高疟区 ,经过多年积极防治 ,发病逐年下降 ,但随着流动人口来往频繁 ,输入疟疾的威胁越来越大。为了解不同疟区疟疾流行现状、评价抗疟措施实施效果。于 1998～ 2 0 0 1年应用 IFAT和 PCR技术对南桥、毛阳不同疟疾流行区进行了纵向调查。结果报告如下。1　资料与方法1.1　调查点概况　南桥乡是间日疟和恶性疟混合流行区 ,抗疟措施落实欠佳 ,年发病率较高 ;毛阳镇是单纯间日疟流行区 ,抗疟措施落实较好 ,采取控制传播媒介和管理传染源综合措施 ,年发病率较低 ,并有效控制了恶性疟传播。1. 2　方法　…     

西藏自治区疟疾流行区传疟媒介研究

近年西藏自治区(简称西藏)林芝地区疟疾疫情一直处于不稳定状态,2010年疟疾发病率跃居全国第二。媒介防制是疟疾综合防治的重要手段,然而西藏疟疾流行区的传疟媒介尚未定论。本文对既往西藏林芝疟疾流行区的传疟媒介相关研究进行综述,以期为西藏疟疾防治提供媒介方面基础的研究信息。     

Predictive factors of malaria in travelers to areas where malaria is endemic

BACKGROUND: The differentiation of malaria from other causes of fever is difficult. The development of tools for rapid and specific clinical diagnosis is of paramount importance for the identification of individuals infected with malaria. METHOD: A 4-year prospective study to identify the clinical and biological variables associated with malaria included all patients suspected of having malaria who presented in the emergency department (ED) of a French hospital. RESULTS: Of 783 patients admitted to the ED with suspected malaria, 145 had positive findings of a thick smear for Plasmodium species, mainly Plasmodium falciparum (90.3%). In univariate analysis, the following 12 variables were significantly associated with diagnosis of malaria: older than 30 years, male sex, immigration to France from an area where malaria is endemic, a visit to sub-Saharan Africa, insufficient antimalaria prophylaxis, fever, chills, absence of diarrhea, a leukocyte count within the reference range, thrombocytopenia, and increased lactate dehydrogenase and bilirubin levels. In multivariate analysis, the factors predictive of malaria included a visit to sub-Saharan Africa (odds ratio [OR], 7.7; 95% confidence interval [CI], 2.8-21.3), a temperature of at least 38.5 degrees C (OR, 6.2; 95% CI, 2.8-13.3), chills (OR, 3.0; 95% CI, 1.4-6.6), thrombocytopenia (OR, 16.5; 95% CI, 7.1-38.3), and abnormally high total bilirubin levels (OR, 21.5; 95% CI, 6.4-72.5). However, alone or combined, these features had insufficient sensitivity (95.0%) and low specificity (55.0%) for the diagnosis of malaria. CONCLUSIONS: Malaria should be suspected in all patients presenting with complaints after travel to an area where malaria is endemic, and these patients should undergo blood microscopy.     

1999年云南省疟疾流行区分层探讨

对云南省1999年疟疾发病率按县或乡镇分层进行探讨,结果表明以乡和地理区域为单位的发病率分层更能如实反映疟疾流行形势,有利于分类指导和分层管理.对边境地区按一、二线乡划分,有利于合理分配有限的资源.     

The potential impact of integrated malaria transmission control on entomologic inoculation rate in highly endemic areas

We have used a relatively simple but accurate model for predicting the impact of integrated transmission control on the malaria entomologic inoculation rate (EIR) at four endemic sites from across sub-Saharan Africa and the southwest Pacific. The simulated campaign incorporated modestly effective vaccine coverage, bed net use, and larval control. The results indicate that such campaigns would reduce EIRs at all four sites by 30- to 50-fold. Even without the vaccine, 15- to 25-fold reductions of EIR were predicted, implying that integrated control with a few modestly effective tools can meaningfully reduce malaria transmission in a range of endemic settings. The model accurately predicts the effects of bed nets and indoor spraying and demonstrates that they are the most effective tools available for reducing EIR. However, the impact of domestic adult vector control is amplified by measures for reducing the rate of emergence of vectors or the level of infectiousness of the human reservoir. We conclude that available tools, including currently neglected methods for larval control, can reduce malaria transmission intensity enough to alleviate mortality. Integrated control programs should be implemented to the fullest extent possible, even in areas of intense transmission, using simple models as decision-making tools. However, we also conclude that to eliminate malaria in many areas of intense transmission is beyond the scope of methods which developing nations can currently afford. New, cost-effective, practical tools are needed if malaria is ever to be eliminated from highly endemic areas.     

Transthyretin-related vitreous amyloidosis in different endemic areas

Background. To investigate the vitreous opacity in patients with familial amyloidotic polyneuropathy (FAP) in two major endemic areas, Japan and Sweden.

Methods. We obtained clinical data for 90 patients with vitreous opacity that was associated with FAP amyloidogenic transthyretin (ATTR) Val30Met; 18 Japanese patients and 72 Swedish patients. We reviewed medical records at Kumamoto University Hospital in Japan and Umeå University Hospital in Sweden. We evaluated the characteristics of the patients, systemic and ocular histories, clinical findings and treatment.

Results. Swedish patients were significantly older at the onset of vitreous opacity (mean age 67.8 years) than were Japanese patients (47.6 years). A similar age difference was found for the onset of polyneuropathy. In addition, Swedish patients without polyneuropathy were significantly older (74.1 years) at the onset of vitreous opacity than those with polyneuropathy (64.6 years). A significant difference in the occurrence of vitreous opacity as the only manifestation of FAP was seen for Swedish patients (35%) compared with Japanese patients (6%).

Conclusions. Swedish FAP ATTR Val30Met patients appeared to develop vitreous opacity later and more frequently compared with Japanese patients.     

New Italian guidelines for malaria prophylaxis in travellers to endemic areas

Background and Methods

As a consequence of the rapid evolution of malaria prophylaxis recommendations throughout the world, the Italian Society of Tropical Medicine (SIMET—Società Italiana di Medicina Tropicale) has set up a working group in charge of preparing a new national guideline. Other scientific societies interested in the topic were also involved in the project.

Results and Conclusions

The group stated that awareness about malaria risk and characteristics, as well as protection from mosquito bites, are recommended for all travellers visiting malaria-endemic countries. The risk and benefit of malaria chemoprophylaxis must be carefully balanced before prescribing drugs: the disease-related risk must outweigh the possibility of drugs’ side effects. As a general rule, malaria pills are the first choice for travellers to high-risk areas, such as sub-Saharan Africa, Eastern India, Myanmar, Eastern Indonesia, Papua New Guinea and, with some limitations, South-East Asia, and the Amazon part of Venezuela, Guyana and French Guyana. However, several other factors, such as itinerary, season, duration of trip, availability of insect bite protection, pre-existing conditions and compliance, must be taken into account. In low-risk areas, stand-by emergency treatment is the first option. In minimal-risk areas and in Plasmodium vivax areas, a prompt diagnosis only is advised (Central America, South America outside the Amazon basin, Middle East, China, Thailand, Nepal). Recommendations may be modified when particular groups of travellers are concerned, such as long-term residents, visiting friends and relatives, patients with pre-existing conditions, pregnant women and children.     

日本血吸虫病流行区HBV与血吸虫感染相关性血清流行病学调查

目的 了解血吸虫病流行区HBsAg人群分布规律及其与血吸虫感染的相关性。方法 在安徽省一中度血吸虫病流行村，采用病原学方法（Kato-Katz法，二送六检）和血清学方法（ELISA法、IHA法串联筛检方案）进行血吸虫感染情况检测，同时平行检测HBsAg（ELISA法），并进行相关个案调查。结果 1）居民HBsAg阳性率11．21％（105／937），其中男性12．38％（50／404），女性10．32％（55／533），性别间差异无显著性（wald=1．545，P=0．214）；25-34岁及以上年龄组HBV感染的危险度（OR）是5～14岁组的8．852～10．5ll倍（P均d0．001）；2）血吸虫抗体阳性率与HBsAg携带率年龄性别分布曲线走向基本一致，有随年龄增大而上升趋势；≥25岁居民血吸虫抗体阳性率、粪检阳性率、HBsAg携带率分别在30％、3．13％和10％以上；3）慢性血吸虫病患者与非血吸虫病患者HBsAg携带率分别为7．69％和9．96％，HBsAg平均A值分别为0．180（一0．005，0．364）和0．234（0，141，0．327），差异无显著性（P均〉0．05）。血吸虫抗体阳性与阴性者HBsAg携带率分别为12．26％、10．66％，HBsAg平均A值分别为0，246（0，166，0．327）和0．241（O．182，0．301），差异无显著性（P均〉0．05）。结论 本研究未发现HBV与血吸虫感染有相关性，但≥25岁居民血吸虫合并HBV感染的潜在威胁不能忽视。     

Analysis of malaria endemic areas on the Indochina Peninsula using remote sensing

We applied remote sensing using satellite images capable of obtaining data over a broad range, transcending national borders, as a method of rapidly, precisely, and safely increasing our understanding of the potential distribution of malaria. Our target region was the so-called Mekong malaria region on the Indochina Peninsula. As a malaria index, we used existing distribution maps of total reported malaria cases, malaria mortality, vivax malaria and falciparum malaria incidences, and so forth for 1997 and 1998. We produced monthly distribution maps of a normalized difference vegetation index (NDVI) with values of 0.2+, 0.3+, 0.35+, and 0.4+ using the geographical information system/remote sensing software based on the East Asia monthly NDVI maps of 1997. These maps were overlaid with various malaria index distribution maps, and cross-tabulations were carried out. The resulting maps with NDVI values of 0.3+ and 0.4+ matched the falciparum malaria distribution well, and we realized, in particular, that falciparum malaria is prevalent in regions in which NDVI values of 0.4+ continue for 6 months or more, while cases are fewer in regions with NDVI values of 0.4+ that continue for 5 months or less. It will be necessary in the future to examine the relationship between NDVI values and the habitats of the various vector mosquitoes using high-resolution satellite images and to implement detailed forecasts for malaria endemic areas by means of NDVI.     

The role of private drug vendors as malaria treatment providers in selected malaria endemic areas of Sri Lanka

BACKGROUND AND OBJECTIVES: The involvement of private drug vendors in malaria treatment is particularly high in developing countries and understanding their practices and knowledge about antimalarials and malaria treatment will aid in devising strategies to increase the correct use of antimalarials and improve adherence to the government's malaria drug policy. Results of a study on the knowledge and practices of the private drug vendors conducted in seven districts in Sri Lanka, mostly in malarious areas are presented. METHODS: Data on awareness of government's malaria drug policy, practice of issuing antimalarials, knowledge about malaria and antimalarial drugs were collected from the drug vendors using pre-tested questionnaire in vernacular language. Data were statistically analysed using Stata 8.2. Chi-square test was carried out for individual explanatory variables and a logistic regression model was applied taking all response variables as binary outcome. RESULTS: Vendors' knowledge on antimalarials was poor with 58% of the vendors being unaware of the government malaria drug policy in the country. Also, the advice provided to customers buying antimalarials was limited. However, the majority of the private vendors emphasised that they were aware of the importance of case confirmation before treatment as stressed in the national policy. Although, the vendors did not have a high awareness of national drug policies they were only found selling chloroquine and primaquine as recommended by the Ministry of Health. INTERPRETATION AND CONCLUSION: In recent years Sri Lanka, as a whole, has experienced very little malaria. The reduction in demand for antimalarials due to low incidence levels may have influenced the knowledge and awareness on antimalarials and government drug policies. However, since low levels of malaria do not guarantee that epidemics will not occur, attempts to educate private drug vendors as a part of an organised control programmes are of major importance.     

黑龙江省地方性氟中毒重病区流行病学现况典型调查

目的 了解黑龙江省饮水型地方性氟中毒重病区现状,为制订地氟病防治策略及政府科学决策提供依据。方法 采用现况典型调查。结果 调查了６个县１５个病区村屯,按８～１２岁儿童氟斑牙指数划分,病情呈显著流行的有安达羊草１、２屯（３．０６）;呈较显著流行的有肇州平等（２．２０）;呈中等流行的有林甸福发（１．６４）、肇州双兴（１．９６）、肇东尚家（１．８６）、安达爱国（１．４２）、肇东海域（１．５７）和新光（１     

Naturally occurring plasmodia-specific circulating immune complexes in individuals of malaria endemic areas in India

Blood samples collected from individuals belonging to malaria endemic areas were assayed for antigen-specific circulating immune complexes in polyethylene glycol precipitates of serum by enzyme immunoassay. Sera were tested from patients with acute P. vivax and P. falciparum infections, from clinically immune individuals and also from healthy normals. Circulating immune complexes (CICs) containing immunoglobulin G and M isotypes were found to be abundant in individuals with ongoing and past infections and also in clinically immune donors. In patients with acute infection but without any past history of malaria, CICs of IgM type were found to be significantly higher. Demonstration of antigen/antibody specific CICs could be a useful indicator of active, ongoing and recent/past infection, also of the status of immune responses of individuals belonging to various endemic areas.     

血吸虫病重疫区居民不同化疗方案的效果

自2003年以来，全国血吸虫病疫区实行吡喹酮免费看服化疗，这是党和政府对广大疫区群众的关心爱护。然而，在现场应用中也存在着一些弊端，吡喹酮免费看服化疗，理论上能达到既能治病又能有效控制传染源的双重效果，减轻农民负担。但由于疫区人口流动性大，现场看服有较大的工作难度，免费不看服又会造成药品浪费。为此，我们在血吸虫病重疫区将现政规定的居民集中时间免费看服化疗与少量收费居民自行服药化疗方案的效果进行比较。[第一段]     

Knowledge about sandflies in relation to public and domestic control activities of kala-azar in rural endemic areas of Bihar

Visceral Leishmaniasis (VL) control is a global cause of concern. To identify the gaps in People's knowledge/awareness about sand flies and control activities of kala-azar in rural endemic areas of Bihar, this study consisting of 450 respondents with 288 male and 162 female was carried out. The result showed that 95% respondents had heard about the disease up to some extent, but majority respondents were neither aware about the vector of kala-azar, nor they had any idea about transmission of the disease. About 61% had wrong impression that mosquitoes were causing kala-azar. Regarding knowledge about breeding and resting sites of vectors, 20% reported cattle shed, 16% crevices in the household followed by 15% damp dark places. The attitude of respondents towards vector control programme was poor, as 99% lost faith in the DDT spraying because of ineffectiveness, like no reduction in mosquito nuisance. Bed net was considered the best protection method against sand fly or mosquito nuisance but the cost was considered the major constraint in its use. Proper health education programme in Simple and local language along with visual demonstration should be promoted to enhance the awareness and co-operation at community level.