Malaria epidemiology in an area of stable transmission in tribal population of Jharkhand, India

Malaria Journal

Research

Régis W. Tiendrebeogo¹  Ikhlaq H. Kana¹  Michael Theisen¹  Manoj K. Das²  Narendra Chauhan³  Harvinder K. Khera³  Subhash Singh³  Amit Srivastava³  Surya Kant Sharma⁴  Kumud Ranjan⁴  Brijesh K. Prajapati⁴  Sanjay Tevatiya⁴  Bright Adu⁵ 

[1] Department for Congenital Disorders, Statens Serum Institut, Artillerivej 5, 2300, Copenhagen, Denmark;Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark;Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark;Field Unit, National Institute of Malaria Research, Ranchi, Jharkhand, India;Indian Institute of Integrative Medicine, Canal Road, 180001, Jammu, India;National Institute of Malaria Research, Indian Council of Medical Research, 110077, New Delhi, India;Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana;

关键词: Malaria;    Plasmodium falciparum;    Plasmodium vivax;    Morbidity;    Age;    Jharkhand;    India;   

DOI  :  10.1186/s12936-017-1833-9

 received in 2017-02-17, accepted in 2017-04-23,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundMalaria remains an important health problem in India with approximately 1 million cases in 2014. Of these, 7% occurred in the Jharkhand state mainly in the tribal population.MethodsThis study was conducted in Dumargarhi, a tribal village about 42 km east of Ranchi city, Jharkhand, from May 2014 to September 2016. Four point prevalence surveys were carried out during consecutive high (October–December) and low (June–August) transmission seasons. Malaria cases were recorded from April 2015 to April 2016 through fortnightly visits to the village. Adult mosquito densities were monitored fortnightly by manual catching using suction tube method.ResultsThe study area consists of five hamlets inhabited by 945 individuals living in 164 households as recorded through a house-to-house census survey performed at enrollment. The study population consisted predominantly of the Munda (n = 425, 45%) and Oraon (n = 217, 23%) ethnic groups. Study participants were categorized as per their age 0–5, 6–10, 11–15 and >15 years. There were 99 cases of clinical malaria from April 2015 to April 2016 and all malaria cases confirmed by microscopy were attributed to Plasmodium falciparum (94 cases) and Plasmodium vivax (5 cases), respectively. During the high transmission season the mean density of P. falciparum parasitaemia per age group increased to a peak level of 23,601 parasites/μl in the 6–10 years age group and gradually declined in the adult population. Malaria attack rates, parasite prevalence and density levels in the study population showed a gradual decrease with increasing age. This finding is consistent with the phenomenon of naturally acquired immunity against malaria. Three vector species were detected: Anopheles fluviatilis, Anopheles annularis, and Anopheles culicifacies. The incoherence or complete out of phase pattern of the vector density peaks together with a high prevalence of parasite positive individuals in the study population explains the year-round malaria transmission in the study region.ConclusionsThe collection of clinical data from a well-characterized tribal cohort from Jharkhand, India, has provided evidence for naturally acquired immunity against malaria in this hyperendemic region. The study also suggests that enforcement of existing control programmes can reduce the malaria burden further.

【 授权许可】

CC BY   
© The Author(s) 2017