The effectiveness of malaria camps as part of the malaria control program in Odisha, India.

Durgama Anchalare Malaria Nirakaran (DAMaN) is a multi-component malaria intervention for hard-to-reach villages in Odisha, India. The main component, Malaria Camps (MCs), consists of mass screening, treatment, education, and intensified vector control. We evaluated MC effectiveness using a quasi-experimental cluster-assigned stepped-wedge study with a pretest-posttest control group in 15 villages: six immediate (Arm A), six delayed (Arm B), and three previous interventions (Arm C). The primary outcome was PCR+ Plasmodium infection prevalence. Across all arms, the odds of PCR+ malaria were 54% lower at the third follow-up compared to baseline. A time (i.e., visit) x study arm interaction revealed significantly lower odds of PCR+ malaria in Arm A versus B at the third follow-up. The cost per person ranged between US$3-8, the cost per tested US$4-7, and the cost per treated US$82-1,614, per camp round. These results suggest that the DAMaN intervention is a promising, financially feasible approach for malaria control.

The burden of submicroscopic and asymptomatic malaria in India revealed from epidemiology studies at three varied transmission sites in India.

Malaria in India, while decreasing, remains a serious public health problem, and the contribution of submicroscopic and asymptomatic infections to its persistence is poorly understood. We conducted community surveys and clinic studies at three sites in India differing in their eco-epidemiologies: Chennai (Tamil Nadu), Nadiad (Gujarat), and Rourkela (Odisha), during 2012-2015. A total of 6,645 subject blood samples were collected for Plasmodium diagnosis by microscopy and PCR, and an extensive clinical questionnaire completed. Malaria prevalence ranged from 3-8% by PCR in community surveys (24 infections in Chennai, 56 in Nadiad, 101 in Rourkela), with Plasmodium vivax dominating in Chennai (70.8%) and Nadiad (67.9%), and Plasmodium falciparum in Rourkela (77.3%). A proportional high burden of asymptomatic and submicroscopic infections was detected in community surveys in Chennai (71% and 71%, respectively, 17 infections for both) and Rourkela (64% and 31%, 65 and 31 infections, respectively). In clinic studies, a proportional high burden of infections was identified as submicroscopic in Rourkela (45%, 42 infections) and Chennai (19%, 42 infections). In the community surveys, anemia and fever were significantly more common among microscopic than submicroscopic infections. Exploratory spatial analysis identified a number of potential malaria hotspots at all three sites. There is a considerable burden of submicroscopic and asymptomatic malaria in malarious regions in India, which may act as a reservoir with implications for malaria elimination strategies.

Evolutionary interplay of single nucleotide polymorphisms at the promoter region of TNF-α gene in different clinical outcomes of malaria in India.

Host genetic factors are frequently ascribed to differential malaria outcomes as a by-product of evolutionary adaptation. To this respect, Tumor Necrosis factor alpha (TNF-α), a human cytokine, is known to be associated with malaria through its differential regulation in diverse malaria manifestations. Since diversity in differential malaria outcome is uncommon in every endemic settings, possible association of TNF-α and malaria is not commonly established. In order to check for association between the occurrence of Single Nucleotide Polymorphisms (SNPs) in the TNF-α gene with different malaria manifestations, we have sequenced a 4011 bp region constituting the promoter and the whole gene of human TNF-α in 61 patients [(16 cerebral plus severe (SCM), 21 severe (SM) and 24 uncomplicated (UM)] samples in a highly malaria endemic state (Odisha) of India. Multiple sequence alignment revealed presence of six SNPs (-1031 T > C, -863C > A, -857C > T, -308G > A, -806C > T, +787C > A), out of which the -806C > T and +787C > A are novel in malaria patients in general and the +787C > A was detected for the first time in humans. Although alleles due to six different SNPs segregate differentially in the three groups of malaria (SCM, SM and UM) in the present study, interestingly, for the -1031 T > C position, the frequency of individuals possessing the homozygous rare allele was higher in the SCM group with a higher number of heterozygotes in the UM group. The Tajima's D values considering all the SNPs in a defined group were positive and statistically insignificant conforming no evolutionary constraint. However, statistically significant deviation from expectation under Hardy-Weinberg equilibrium for -1031 T > C SNP in the UM group points towards the probable role of natural selection providing some kind of protection to malaria in Odisha, India.

The use of mosquito repellents at three sites in India with declining malaria transmission: surveys in the community and clinic.

BACKGROUND: Repellents such as coils, vaporizers, mats and creams can be used to reduce the risk of malaria and other infectious diseases. Although evidence for their effectiveness is limited, they are advertised as providing an additional approach to mosquito control in combination with other strategies, e.g. insecticide-treated nets. We examined the use of repellents in India in an urban setting in Chennai (mainly Plasmodium vivax malaria), a peri-urban setting in Nadiad (both P. vivax and P. falciparum malaria), and a more rural setting in Raurkela (mainly P. falciparum malaria). METHODS: The use of repellents was examined at the household level during a census, and at the individual level in cross-sectional surveys and among patients visiting a clinic with fever or other symptoms. Factors associated with their use were examined in a multivariate analysis, and the association between malaria and the use of repellents was assessed among survey- and clinic participants. RESULTS: Characteristics of participants differed by region, with more people of higher education present in Chennai. Use of repellents varied between 56-77 % at the household level and between 32-78 % at the individual level. Vaporizers were the main repellents used in Chennai, whereas coils were more common in Nadiad and Raurkela. In Chennai and Nadiad, vaporizers were more likely to be used in households with young male children. Vaporizer use was associated with higher socio-economic status (SES) in households in Chennai and Nadiad, whereas use of coils was greater in the lower SES strata. In Raurkela, there was a higher use of coils among the higher SES strata. Education was associated with the use of a repellent among survey participants in Chennai and clinic study participants in Chennai and Nadiad. Repellent use was associated with less malaria in the clinic study in Chennai and Raurkela, but not in the surveys, with the exception of the use of coils in Nadiad. CONCLUSIONS: Repellents are widely used in India. Their use is influenced by the level of education and SES. Information on effectiveness and guidance on choices may improve rational use.