Mass drug administration for the control and elimination of Plasmodium vivax malaria: an ecological study from Jiangsu province, China

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Recent progress in malaria control has caused renewed interest in mass drug administration (MDA) as a potential elimination strategy but the evidence base is limited. China has extensive experience with MDA, but it is not well documented.
Methods

An ecological study was conducted to describe the use of MDA for the control and elimination of Plasmodium vivax in Jiangsu Province and explore the association between MDA and malaria incidence. Two periods were focused on: 1973 to 1983 when malaria burden was high and MDA administered to highly endemic counties province-wide, and 2000 to 2009, when malaria burden was low and a focal approach was used in two counties. All available data about the strategies implemented, MDA coverage, co-interventions, incidence, and adverse events were collected and described. Joinpoint analysis was used to describe trends in incidence and the relationship between MDA coverage and incidence was explored in negative binomial regression models.
Results

From 1973 to 1983, MDA with pyrimethamine and primaquine was used on a large scale, with up to 30 million people in target counties covered in a peak year (50% of the total population). Joinpoint analyses identified declines in annual incidence, -56.7% (95% CI -75.5 to -23.7%) from 1973–1976 and -12.4% (95% CI -24.7 to 2.0%) from 1976–1983. Population average negative binomial models identified a relationship between higher total population MDA coverage and lower monthly incidence from 1973–1976, IRR 0.98 (95% CI 0.97 to 1.00), while co-interventions, rainfall and GDP were not associated. From 2000–2009, incidence in two counties declined (annual change -43.7 to -14.0%) during a time when focal MDA using chloroquine and primaquine was targeted to villages and/or individuals residing near passively detected index cases (median 0.04% of total population). Although safety data were not collected systematically, there were rare reports of serious but non-fatal events.
Conclusions

In Jiangsu Province, China, large-scale MDA was implemented and associated with declines in high P. vivax malaria transmission; a more recent focal approach may have contributed to interruption of transmission. MDA should be considered a potential key strategy for malaria control and elimination.

AUTHORS: Michelle S Hsiang, Jimee Hwang, Amy R Tao, Yaobao Liu, Adam Bennett, George Dennis Shanks, Jun Cao, Stephen Patrick Kachur, Richard GA Feachem, Roly D Gosling and Qi Gao

Source: Malaria Journal 2013, 12:383 doi:10.1186/1475-2875-12-383
http://www.malariajournal.com/content/12/1/383/abstract
Published: 1 November 2013

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

First in Malaria: U.S. or China?

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QUESTION

Who discovered the world’s first malaria vaccine? Is it the US marines in Washington DC or the People’s Republic of China?

ANSWER

Unfortunately there is still no effective malaria vaccine.  You might be referring to the race between the US and China to find an effective malarial treatment during the Vietnam War years.  Currently, artemisinins, from the wormwood plant, discovered in China is the recommended treatment for malaria caused by Plasmodium falciparam.

New Partners Join the Asia Pacific Malaria Elimination Network (APMEN)

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The Asia Pacific Malaria Elimination Network (APMEN) has announced two new Partner Institutions have joined the organization: The Mahidol Vivax Research Center and the Malaria Research Centre, Universiti Malaysia Sarawak.

The Mahidol Vivax Research Center (MVRC) established in March 2011 is dedicated to the study of Plasmodium vivax and non falciparum malaria. Its establishment at Mahidol University in Thailand is important to the region, as Mahidol has a long record in the field of tropical disease medicine and research. Mahidol Vivax Research Center was initiated by the Dean of the Faculty of Tropical Medicine, Mahidol University, Associate Professor Pratap Singhasivanon and is directed by Dr. Jetsumon Prachumsri, formerly the leader of malaria research at the Armed Forces Research Institutes of Medical Sciences (AFRIMS) and APMEN Partner Institution representative.

The Malaria Research Centre was established at the Universiti Malaysia Sarawak in 2006 in recognition of the major contribution to malaria research by Professor Balbir Singh, Professor Janet Cox-Singh, and co-researchers at the Malaria Research Laboratory in the Faculty of Medicine and Health Sciences. MRC-UNIMAS is known for its work on Plasmodium knowlesi that was recognised by the World Health Organization (WHO) in 2008 as the fifth species of Plasmodia parasite to infect humans in the wild.

MRC-UNIMAS found that many malaria infections in Sarawak, Malaysia, had been incorrectly diagnosed and a major cause of malaria was Plasmodium knowlesi that is transmitted via the bit of an Anopheline mosquito from long-tail and pig-tail macaques. P knowlesi has also been reported in other parts of Malaysia, Indonesia, and Philippines and may be endemic in more countries in Southeast Asia. The final elimination of malaria in the Asia Pacific region will depend on a greater understanding of P knowlesi and how we can target this zoonosis.

The Malaria Research Centre, Universiti Malaysia Sarawak and the Mahidol Vivax Research Center have already supported APMEN through their active participation at last year’s annual meeting in Kota Kinabalu, Malaysia.

The fourth annual APMEN Annual Meeting will be held in May 2012 in Seoul, Republic of Korea. This year’s meeting will focus on how to sustain the gains made in the elimination of malaria and the importance in the coming years of maintaining successful approaches and their support. The region has many challenges to face in malaria elimination, in particular P. vivax, a type of malaria that is more difficult to diagnose and treat than P falciparum, the type of malaria most often discussed at a global level. APMEN through its information exchange, capacity building, and evidence building and advocacy activities is committed to supporting and maintaining elimination efforts in the Asia Pacific Region.

About the Asia Pacific Malaria Elimination Network
The Asia Pacific Malaria Elimination Network (APMEN) was established in 2009 to bring attention and support to the under-appreciated and little-known work of malaria elimination in Asia Pacific, with a particular focus on Plasmodium vivax.

APMEN is composed of 12 Asia Pacific countries (Bhutan, Cambodia, China, Democratic People’s Republic of Korea, Indonesia, Malaysia, Philippines, Republic of Korea, the Solomon Islands, Sri Lanka, Thailand, and Vanuatu) that are pursuing malaria elimination, as well as leaders and experts from key multilateral and academic agencies. The mission of this diverse but cohesive Network is to collaboratively address the unique challenges of malaria elimination in the region through leadership, advocacy, capacity building, knowledge exchange, and building the evidence base.

Development of the Network took place in 2008 through the leadership of the UCSF Global Health Group (GHG) and the School of Population Health, University of Queensland (SPH/UQ). APMEN collaborates closely with the WHO and is supported by the Australian Government through its international aid agency AusAID with a commitment of nearly $7 million for ongoing support to the Network. This complements Australia’s overall support for malaria control and elimination in the Asia Pacific and globally.

Source: Asia Pacific Malaria Elimination Network (APMEN)

Can Slide Positivity Rates Predict Malaria Transmission?

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Malaria is a significant threat to population health in the border areas of Yunnan Province, China. How to accurately measure malaria transmission is an important issue. This study aimed to examine the role of slide positivity rates (SPR) in malaria transmission in Mengla County, Yunnan Province, China. [Read more…]

Herbal Treatment for Malaria

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QUESTION

Can any form of malaria be treated by herbs or plants, and how long does it take to recover from malaria?

ANSWER

Actually, two of the most important kinds of anti-malarial medication are derived by substances found naturally in plants, though they need to be processed in certain ways before the full pharmaceutical effect is felt.

Quinine, administered intravenously, is currently the first-line treatment for complicated malaria (i.e. when the patient has a history of high fever, plus additional severe symptoms such as impaired consciousness). It is derived from the bark of trees of the genus Cinchona, which are native to the tropical rainforests of western South America. Long known to native populations for its medicinal properties, it became known to Europeans in the early 17th century when the Countess of Chinchón, the wife of the viceroy of Peru at the time, was cured by it, having been suffering from what was likely malaria.

Similarly, artemisinin, currently used in combination with other anti-malarial compounds as the first-line treatment against non-complicated malaria (these combinations are known as artemisinin-based combination therapies, or ACTs), is derived from wormwood, a shrub native to Asia but now found throughout the world. As with the Cinchona trees, traditional healers in China had used wormwood to treat fever for thousands of years, but its use had been forgotten in modern times, until its rediscovery in the 1970s. Nowadays, artemisinin is not recommended for treatment alone, as it is feared this will lead to resistance developing, and so it is only used in the combination therapies described above.

If treated promptly, and with the correct form of medication, recovery from malaria can take only a few days. If not, recovery can take much longer (even up to weeks), and in the case of P. falciparum malaria, the most deadly kind, the infection can become life threatening in only a day or two. P. knowlesi (found in parts of south-east Asia), though less fatal than P. falciparum, can also become severe rapidly, and so prompt treatment is especially necessary for these two kinds of malaria.

Breeding Site Characterization of Anopheles Sinensis Larvae in Chinese Villages

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Characterizing the breeding site of Anopheles sinensis is of major importance for the transition from malaria control to elimination in China. However, little information is available especially regarding the characteristics and influencing factors of breeding sites of An. sinensis in Yongcheng City, a representative region of unstable malaria transmission in the Huang-Huai River region of central China.

The aims of this study were to determine the breeding site characteristics of An. sinensis and related environmental and physicochemical parameters, to find out which breeding site characteristics could best explain the presence of An. sinensis larvae, and to determine whether the breeding habit of An. sinensis has changed or not.

Methods

Random repeated cross sectional study was undertaken in six villages of the Yongcheng city characterized by different levels of the historical incidence of P. vivax malaria. The potential breeding sites of An. sinensis larvae in each village were examined twice per month both in the household courtyards and the village surroundings. The larval sampling was done by the standard dipping method. Some important breeding site characterizations were recorded and characterized. The anopheline mosquito larvae and emerged adults were identified to the species level morphologically and to sub-species by the ribosomal DNA PCR technique. Chi-square analysis and logistic regression analysis were applied to determine the importance of factors for explaining the presence or absence of An. sinensis larvae.

Results

According to the ribosomal DNA PCR assay, all sampled anopheline mosquito larvae and emerged adults belonged to An. sinensis. Only 3 containers that were sampled from the household courtyards were found to contain An. sinensis larvae. There were no differences in the species composition of mosquito larvae among containers that contained water in the household courtyards (P > 0.05). An. sinensis larvae were shown to be present in a total of 60 breeding sites in the village surroundings, this included 8 (13.3%) river fringes, 26 (43.3%) ponds, 23 (38.3%) puddles, and 3 (5.0%) irrigation/drainage ditches. Logistic regression analysis revealed that the breeding site type, water depth, chemical oxygen demand (COD), ammonia nitrogen, and sulphate were found to be the key factors determining the presence of An. sinensis larvae. Approximately 94.9% of An. sinensis larvae inhabited relatively large and medium-sized water bodies, with depths between 0.5 m and 1.0 m (73.3%), COD lower than 2 mg/L (75%), ammonia nitrogen lower than 0.4 mg/L (86.7%), and sulphate lower than 150 mg/L (58.3%), respectively.

Conclusion

These results indicate that the majority of An. sinensis larval breeding sites were relatively large and medium-sized water bodies with depths between 0.5 m and 1.0 m, and containing low levels of COD, ammonia nitrogen, and sulphate, respectively. For effective An. sinensis larval control, the type of breeding site, water depth, COD, ammonia nitrogen, and sulphate should be given higher priority over other factors in areas where it is the primary vector.

Authors: Xiao-Bo Liu, Qi-Yong Liu, Yu-Hong Guo, Jing-Yi Jiang, Dong-Sheng Ren, Guang-Chao Zhou, Can-Jun Zheng, Jing-Li Liu, Yun Chen, Hong-Sheng Li, Hua-Zhong Li and Qun Li

Full Article: Random repeated cross sectional study on breeding site characterization of Anopheles sinensis larvae in distinct villages of Yongcheng City, People’s Republic of China (PDF)

Source: Parasites & Vectors 2012, 5:58 doi:10.1186/1756-3305-5-58

Published: 23 March 2012

Copyright: © 2012 Xiao-Bo Liu et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.