Overhead tank is the potential breeding habitat of Anopheles stephensi in an urban transmission setting of Chennai, India

Background: Wells and overhead tanks (OHT) are the major breeding sources of the local malaria vector, Anopheles stephensi in the Indian city of Chennai; they play a significant role in vector breeding, and transmission of urban malaria. Many other man-made breeding habitats, such as cemented cisterns/containers, barrels or drums, sumps or underground tanks, and plastic pots/containers are maintained to supplement water needs, temporarily resulting in enhanced mosquito/vector breeding. Correlating breeding habitats with immature vector abundance is important in effective planning to strengthen operational execution of vector control measures. Methods: A year-long, weekly study was conducted in Chennai to inspect available clear/clean water mosquito breeding habitats. Different breeding features, such as instar-wise, immature density and co-inhabitation with other mosquito species, were analysed. The characteristics of breeding habitats, i.e., type of habitat, water temperature and presence of aquatic organisms, organic matter and green algal remnants on the water surface at the time of inspection, were also studied. Immature density of vector was correlated with presence of other mosquito species, malaria prevalence, habitat characteristics and monthly/seasonal fluctuations. All the data collected from field observations were analysed using standard statistical tools. Results: When the immature density of breeding habitats was analysed, using one-way ANOVA, it was observed that the density did not change in a significant way either across seasons or months. OHTs contributed significantly to the immature population when compared to wells and other breeding habitats of the study site. The habitat positivity of wells and OHTs was significantly associated with the presence of aquatic organisms, organic matter and algal remnants. Significant correlations of malaria prevalence with monthly immature density, as well as number of breeding habitats with immature vector mosquitoes, were also observed. Conclusions: The findings that OHTs showed fairly high and consistent immature density of An. stephensi irrespective of seasons indicates the potentiality of the breeding habitat in contributing to vector density. The correlation between vector breeding habitats, immature density and malaria prevalence indicates the proximity of these habitats to malaria cases, proving its role in vector abundance and local malaria transmission. The preference of An. stephensi to breed in OHTs calls for intensified, appropriate and sustained intervention measures to curtail vector breeding and propagation to shrink malaria to pre-elimination level and beyond

Isolated lesions of gingiva: A case series and review

Isolated lesions of gingiva arise in succession to the hyperinflammatory reactions in response to the underlying local irritants. Despite their overlapping clinical and histological features, these lesions are distinctive regarding their biological behavior. Recurrence has been reported after surgical excision because of the incomplete removal of underlying local irritants. This article describes the clinical and histological features of four localized gingival lesions, adding a note on their molecular pathogenesis and surgical management

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