Dengue in India: An Overview

Background: Dengue fever has become a major public health concern in our country, causing significant morbidity and mortality. Because there is no definite drug or commercially available vaccine for dengue, prevention is the only option. As a result, early reporting of dengue cases is required in order to implement preventive measures before the disease spreads to epidemic proportions. Therefore, healthcare providers should notify every dengue incident to local authorities in the current format, including the District Health Officer or Chief Medical Officer of district concerned and the Municipal Health Officer of municipality concerned every week (daily during the transmission period). Materials and Methods: The data on dengue (2015-2021 till Oct.) was available at the National Vector Borne Disease Control Programme under the Ministry of Health & Family Welfare, Government of India, and has been used in this paper. Results and discussion: During the last two decades (2000-2009 and 2010-2019), significant geographical spread of the dengue has been experienced in India with the repeated outbreaks, and an 11 fold increase in number of cases. Despite an increase in the incidence of dengue fever, the case fatality rate in India has decreased from 3.3% in 1996 to 0.4% in 2010 to 0.1% in 2019. Early diagnosis and timely referral play a critical role in bringing down Case Fatality Rate (CFR). Conclusion: Dengue is a manifestation arising from the process of increasing vector density and adaptation to human habitation, as well as human lifestyle transformation, unplanned developmental activities exacerbated by climate change.

Knowledge, Attitude and Practice in Dengue Endemic Areas in Madurai District

Introduction: Dengue fever, otherwise called break bonefever, is a mosquito borne tropical illness brought aboutby the dengue virus. In the present study an attempt wasmade to identify the reason for the year wise increase ofdengue incidence in Madurai District .The object of MedicalGeography is to study the geographical environment of humansociety and its influence on the health of man. In this directionthe present study helps to understand how the disease governedby people attitude, behavior and knowledge among dengueMaterial and Methods: To fulfill the objectives Primary andSecondary data were collected. Stratified random samplingmethod was used to collect the primary data.450 respondentswho were interviewed by direct questionnaire method, 20variables were selected. Year wise dengue cases were collectedfrom Deputy Directorate of Health Department Madurai.Results: During the previous ten years dengue cases becomeexpanding significantly in Madurai district. In 2017 thepercentage of dengue infection attains its zenith. Whencompared to 2012 dengue infection is doubled as 51% of casesin 2017. The increasing or decreasing rate of dengue infectiondepends on the knowledge, attitude and practice of peopleamong dengue and it seems low in educated people also.Conclusion: Dengue affected areas not up to the mark evenin educated people also. The initial phase in real life againstthe dengue mosquito is to educate communities about whatdengue is and what measure can be taken to battle it. A reliablewater supply is essential to prevent dengue fever. Watershortage force people to store water, which leads to breedingplaces for dengue mosquitoes.

Entomopathogenic fungi and their potential for the management of Aedes aegypti (Diptera: Culicidae) in the Americas

Classical biological control has been used extensively for the management of exotic weeds and agricultural pests, but never for alien insect vectors of medical importance. This simple but elegant control strategy involves the introduction of coevolved natural enemies from the centre of origin of the target alien species. Aedes aegypti - the primary vector of the dengue, yellow fever and Zika flaviviruses - is just such an invasive alien in the Americas where it arrived accidentally from its West African home during the slave trade. Here, we introduce the concept of exploiting entomopathogenic fungi from Africa for the classical biological control of Ae. aegypti in the Americas. Fungal pathogens attacking arthropods are ubiquitous in tropical forests and are important components in the natural balance of arthropod populations. They can produce a range of specialised spore forms, as well as inducing a variety of bizarre behaviours in their hosts, in order to maximise infection. The fungal groups recorded as specialised pathogens of mosquito hosts worldwide are described and discussed. We opine that similar fungal pathogens will be found attacking and manipulating Ae. aegypti in African forests and that these could be employed for an economic, environmentally-safe and long-term solution to the flavivirus pandemics in the Americas.

Zika virus infection during pregnancy and microcephaly occurrence: a review of literature and Brazilian data

Abstract In November of 2015, the Ministry of Health of Brazil published an announcement confirming the relationship between Zika virus and the microcephaly outbreak in the Northeast, suggesting that infected pregnant women might have transmitted the virus to their fetuses. The objectives of this study were to conduct a literature review about Zika virus infection and microcephaly, evaluate national and international epidemiological data, as well as the current recommendations for the health teams. Zika virus is an arbovirus, whose main vector is the Aedes sp. The main symptoms of the infection are maculopapular rash, fever, non-purulent conjunctivitis, and arthralgia. Transmission of this pathogen occurs mainly by mosquito bite, but there are also reports via the placenta. Microcephaly is defined as a measure of occipto-frontal circumference being more than two standard deviations below the mean for age and gender. The presence of microcephaly demands evaluation of the patient, in order to diagnose the etiology. Health authorities issued protocols, reports and notes concerning the management of microcephaly caused by Zika virus, but there is still controversy about managing the cases. The Ministry of Health advises notifying any suspected or confirmed cases of children with microcephaly related to the pathogen, which is confirmed by a positive specific laboratory test for the virus. The first choice for imaging exam in children with this malformation is transfontanellar ultrasound. The most effective way to control this outbreak of microcephaly probably caused by this virus is to combat the vector. Since there is still uncertainty about the period of vulnerability of transmission via placenta, the use of repellents is crucial throughout pregnancy. More investigations studying the consequences of this viral infection on the body of newborns and in their development are required.

Zika virus:An update review / 中华微生物学和免疫学杂志

Zika virus (ZIKV) was first isolated in 1947. It is known to circulate mainly in tropical areas and can be transmitted through Aedes mosquitoes. In 2015, an outbreak of ZIKV began in Brazil and then spread rapidly to the Latin Americans and Caribbean. Accumulating evidence indicates that there are associations between ZIKV infection and human nervous disorders, such as the occurrence of microcephaly in neonates and Guillain-Barré syndrome in adults. The current ZIKV outbreak has been declared a public health emergency of international concern. Here, we review the virological features, transmission and epide-miological characteristics of ZIKV and the clinical featrues and prevention of ZIKV infection.

Chikungunya infection: A potential re-emerging global threat

Infectious diseases are indeed a lifelong threat to everyone irrespective of age, sex, lifestyle and socio-economic status. The infectious diseases have persisted among the prominent causes of death globally. Recently, re-emergence of Chikungunya viral infection harmed many in Asian and African countries. Chikungunya was considered as a major threat in developing and under-developed countries; the recent epidemiological outbreak of Chikungunya in La Reunion urges the global researchers to develop effective vaccine against this viral disease. In this review, Chikungunya, pathogenesis and epidemiology were briefly described.

Chikungunya infection: A potential re-emerging global threat

Infectious diseases are indeed a lifelong threat to everyone irrespective of age, sex, lifestyle and socio-economic status. The infectious diseases have persisted among the prominent causes of death globally. Recently, re-emergence of Chikungunya viral infection harmed many in Asian and African countries. Chikungunya was considered as a major threat in developing and under-developed countries; the recent epidemiological outbreak of Chikungunya in La Reunion urges the global researchers to develop effective vaccine against this viral disease. In this review, Chikungunya, pathogenesis and epidemiology were briefly described.

Status of circulating immune complexes, IL8 titers and cryoglobulins in patients with dengue infection.

Dengue, a serious viral infection caused by the mosquito vector, Aedes aegyptii, affects about 390 million people annually from more than 125 countries across the globe. However, until now, there is no reliable clinical or laboratory indicator to accurately predict the development of dengue severity. Here, we explored critical pathophysiological determinants like IL8, circulating immune complex (CIC) and cryoglobulin in dengue-infected patients for identification of novel dengue severity biomarker(s). Totally, 100 clinically suspected dengue cases were tested by NS1 ELISA and MAC ELISA for dengue virus aetiology. For control, 49 healthy volunteers were included. Blood profiling (complete hemogram and liver function test) of patient population were done using automated cell counter and standard auto analyzer based biochemical analysis. Serum CIC was quantified by PEG precipitation. Serum cryoglobulins were estimated by Folin assay. Levels of serum IL-8 were assessed by standard sandwich ELISA kits. Patient CIC were further characterized by SDS Gel electrophoresis. Forty per cent of the cases tested positive, of which 11 patients had severe clinical manifestation. The mean ±SEM of cryoglobulin concentration for DHF, DF, and HC were 1.30±0.31, 0.59±0.08 and 0.143±0.009 μg/μl, respectively. Thus, DHF and DF patients have shown 9- and 2.2-fold increase in cryoglobulin levels; and 18- and 5-fold increased CIC, respectively compared to HC patients. The mean ±SEM of CIC-PEG index for DHF, DF and HC were 491±41.22, 146±14.19 and 27.98±2.56, respectively. Raised levels of IL8 titers were also found in all 11 DHF patients. Peak levels of CIC, cryoglobulin and IL8 titers were associated with thrombocytopenia. SDS PAGE analysis of CIC from DHF revealed the presence of at least six protein bands that were not observed in samples from DF and HC. Prediction efficacy of IL8, CIC and cryoglobulin for DHF was determined using the receiver operator characteristic curve (ROC). The area under the curve was 1.00 for IL8, 0.99 for CIC and 0.74 for cryoglobulins. Overall, the results suggest that CIC, IL-8 and cryoglobulins may serve as important laboratory parameters to monitor dengue infection progression.

Dengue in India.

Dengue virus belongs to family Flaviviridae, having four serotypes that spread by the bite of infected Aedes mosquitoes. It causes a wide spectrum of illness from mild asymptomatic illness to severe fatal dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS). Approximately 2.5 billion people live in dengue-risk regions with about 100 million new cases each year worldwide. The cumulative dengue diseases burden has attained an unprecedented proportion in recent times with sharp increase in the size of human population at risk. Dengue disease presents highly complex pathophysiological, economic and ecologic problems. In India, the first epidemic of clinical dengue-like illness was recorded in Madras (now Chennai) in 1780 and the first virologically proved epidemic of dengue fever (DF) occurred in Calcutta (now Kolkata) and Eastern Coast of India in 1963-1964. During the last 50 years a large number of physicians have treated and described dengue disease in India, but the scientific studies addressing various problems of dengue disease have been carried out at limited number of centres. Achievements of Indian scientists are considerable; however, a lot remain to be achieved for creating an impact. This paper briefly reviews the extent of work done by various groups of scientists in this country.