Physiographic and entomologic risk factors of Malaria in Assam, India

Malaria Research Centre (Indian Council of Medical Research), PO Sonapur, Kamrup, Assam 782 402, India.
The American journal of tropical medicine and hygiene (Impact Factor: 2.7). 11/2004; 71(4):451-6.
Source: PubMed


Fever surveys were conducted in several districts of the Indian state of Assam to ascertain the prevalence of malaria in relation to vector abundance, entomologic inoculation rates (EIRs), and geographic location of human settlements. Anopheles minimus were incriminated, but their relative abundance and biting rates varied among districts, and no significant correlation was observed between these two indicators (r = 0.43, P = 0.34). Plasmodium falciparum was the predominant parasite species except in two districts where P. vivax was the majority parasite. The EIRs per person/night were 0.46-0.71 in P. falciparum-predominant areas and 0.12 in the district where P. vivax predominated. The correlation of percentage of fever cases positive for malaria infection in each district with the corresponding EIR was not significant (r = 0.6, P = 0.21). Malaria cases were detected in all months of the year but peaked during May-June, which corresponded to the months of heavy rainfall. These were also the months with highest incidence of infection with P. falciparum. Malaria cases were observed in all age groups of both sexes, and there was clustering of cases in villages near the vector-breeding habitat (perennial seepage streams), and foothill villages. However, malaria incidences were consistently lower in villages within 5 km of the nearest health care facility, which were in town areas. The data presented are indicative of low-to-moderate levels of malaria transmission by An. minimus, and would be of value for developing future intervention strategies.

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    • "The state of Assam and AP alone contributes 42% and 12% of malaria cases respectively in the NER [5] . Assam alone shares more than 5% of cases reported in India annually [6] . "
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    ABSTRACT: To depict mitochondrial genetic variation for the first time among Anopheles minimus (An.minimus) (Diptera: Culicidae) species from two malaria endemic states of NE India. Phylogeographic analysis was carried at 9 out of 12 sites of An.minimus confirmed malaria endemic places. All sequences were Adenine-Thymine rich regions. Transitions were observed in 6 sequences where 5 mutations were synonymous substitutions and in 1 case non synonymous mutation was observed. Three distinct clusters of haplotypes were generated. Haplotype diversity and low nucleotide diversity were studied. Overall negative values obtained from Tajima's D test and Fu'sFS test indicate a recent genetic population expansion. Network analysis has explained sequence diversity that was also shown by mutations in 6 sequences. High genetic diversity observed within the populations of An.minimus species has several possible implications for vector control in the region. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.
    Asian Pacific Journal of Tropical Medicine 12/2014; 7(12). DOI:10.1016/S1995-7645(14)60168-1 · 0.93 Impact Factor
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    • "People live under low socio-economic conditions and have high levels of immunity enabling them to serve as reservoirs for malaria transmission [11]. Poor socio-economic conditions, knowledge and perception about malaria and antimalarial policies have contributed to widespread malaria throughout the region [8,9,12-14]. Similar to other malaria endemic countries, personal protection using ITNs and malaria treatment with an effective antimalarial are the main strategies against malaria in India ( "
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    Infectious Diseases of Poverty 06/2014; 3:19. DOI:10.1186/2049-9957-3-19 · 4.11 Impact Factor
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    • "Malaria is a major public health problem in southeastern Bangladesh and remains one of the most common reasons for hospital admissions during the malaria season [15]. Mapping of high-risk areas is essential for planning health interventions [37]. The primary objective of this investigation was to establish detailed baseline data on the prevalence and distribution of malaria in both symptomatic and asymptomatic carriers of Plasmodium parasites in southeastern Bangladesh. "
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    Malaria Journal 01/2014; 13(1):16. DOI:10.1186/1475-2875-13-16 · 3.11 Impact Factor
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