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Biomedical subjects

K Satyanarayana

Publications and source records attributed to K Satyanarayana.

At least 19 recordsLinked to original sources
PubMed2006

Community-based study to assess the efficacy of DEC plus ALB against DEC alone on bancroftian filarial infection in endemic areas in Tamil Nadu, south India.

As part of the Global Programme for Elimination of Lymphatic Filariasis (GPELF), India is implementing mass drug administration (MDA) with annual single dose of diethylcarbamazine (DEC) with and without albendazole (ALB). The impact of MDAs on filarial infections and soil-transmitted helminth (STH) infections was assessed during a 3-year period in two communities, one with DEC + ALB and the other with DEC alone. Prior to each MDA (during 2001, 2002 and 2003), filarial indices (microfilaraemia and antigenaemia) were assessed from blood samples of 450-650 persons aged 2-25 years and STH infections in stool samples (Kato-Katz method) from 325 to 500 children aged 9-10 years. Mosquitoes resting indoors were collected to determine the filarial infection status. The microfilaraemia prevalence decreased significantly (P < 0.05) in both arms, with the highest decline in the DEC + ALB arm (72%vs. 51%). Decline in micrefilaria intensity was also higher in the DEC + ALB arm (81.4%vs. 48.5%). In this arm alone, the antigenaemia prevalence was reduced significantly (62%; P < 0.001). The reduction in STH prevalence was lower in the DEC alone arm (6.5%; NS) than in the DEC + ALB arm (70.9%; P < 0.001). Also, the egg reduction in DEC alone arm was only half that of DEC + ALB arm (49%vs. 97%). Our community-based follow-up study showed higher and sustained benefits with regard to filarial and STH infections for the two-drug arm over the DEC alone arm. The trends suggest that at least 10 MDAs may be necessary to achieve the goal of elimination.

Adolescent↗
PubMed2005

The 2001 dengue epidemic in Chennai.

UNLABELLED: Dengue is emerging as a serious public health problem in Tamil Nadu. The present surveillance system is unlikely to generate proper information on the epidemiology of the disease, which is essential for planning and development of relevant control/preventive measures against dengue. OBJECTIVE: Between November 2001 and January 2002, a descriptive study was undertaken on children with clinical dengue attending Kanchi Kamakoti Child Trust Hospital (KKCTH, a major private referral pediatric hospital in Tamil Nadu, India) to define the magnitude of dengue burden, the natural history of this disease in terms of clinical presentation, and outcome of the infections in hospitalized children (< 15) with clinical dengue. METHODS: The sera collected from patients analyzed for dengue specific IgM and IgG antibodies by IgM, IgG antibody capture enzyme linked immunosorbent assay (ELISA) using alternatively two commercial kits. World Health Organization clinical case definition was adopted to categorize the dengue confirmed children. RESULTS: Dengue was diagnosed in 74.5% (143) of the 192 hospitalized children with clinical dengue. A considerable proportion (20%) of the total dengue infections were constituted by infants less than 1 yr of age. DF [dengue fever], DHF [dengue hemorrhagic fever] and DSS [dengue shock syndrome] were diagnosed in 65%, 11.2% and 23.8% of 143 dengue confirmed patients respectively. Though severe dengue (DSS + DHF) was present in 35% of the patients, the mortality rate was low during the study period due to timely diagnosis and clinical management of the patients. CONCLUSION: In developing countries like India, building of laboratory capacity for diagnosis and combat-mode ready preparedness for the management of dengue cases in emergency situation may reduce dengue-related mortality. This can be achieved in a wider scale through an integrated approach through the community, professionals and the public health departments.

Adolescent↗
PubMed2005

Efficacy of thermal fog application of deltacide, a synergized mixture of pyrethroids, against Aedes aegypti, the vector of dengue.

We evaluated the efficacy of indoor and peridomestic thermal fog applications of deltacide, a synergized mixture of pyrethroids (S-bioallethrin 0.7% w/v, deltamethrin 0.5% w/v and piperonyl butoxide 8.9% w/v) against adult populations of Aedes aegypti in Chennai, Tamil Nadu, India. We bioassayed adult caged mosquitoes, counted indoor resting and human landing adult mosquitoes and assessed the percentage of potential breeding sites with Aedes larvae. The bioassay mortalities indicated that the knockdown and killing effect was greater when fogging was applied inside houses rather than around them. Peridomestic thermal fogging reduced the resting and biting populations by 76% and 40%, respectively for the 3 days after treatment, whereas indoor fogging suppressed adult populations for 5 days.

Aedes↗
PubMed2004

Knowledge and beliefs about elephantiasis and hydrocele of lymphatic filariasis and some socio-demographic determinants in an endemic community of Eastern India.

This study reports the knowledge and beliefs about filarial elephantiasis and hydrocele of people from an endemic area of Orissa, India. Both qualitative and quantitative data were collected from 12 villages, sampled from four blocks in the Khurda district of Orissa. This study found that people were aware of different manifestations of filariasis, and perceived them as problems in their community. A high proportion of people knew that mosquitoes are the reason for the spread of elephantiasis, but less people were aware of the cause of hydrocele and the association between elephantiasis and hydrocele. Only half of the respondents believed that elephantiasis is curable by modern medicines, and about 84% of respondents thought that surgery is the only method to cure hydrocele. About two-thirds of people know that avoiding mosquitoes can prevent elephantiasis. Age, gender, educational level and caste affiliation were identified as factors influencing awareness and knowledge. These findings may be used in the development of group-specific health education programmes to change health behaviour and to achieve higher involvement of the community in annual mass drug administration to eliminate lymphatic filariasis.

Adolescent↗
PubMed2004

Impact of two annual single-dose mass drug administrations with diethylcarbamazine alone or in combination with albendazole on Wuchereria bancrofti microfilaraemia and antigenaemia in south India.

A two-arm community-based lymphatic filariasis elimination trial is being carried out in Tamil Nadu state, India to assess the effect of 2 annual single-dose mass drug administrations of diethylcarbamazine + albendazole (DEC + ALB) on microfilaraemia and antigenaemia in one arm, and diethylcarbamazine(DEC) alone in the other arm. In a cross-sectional survey at each time-point, 450-650 subjects in childhood (2-9 years old) and young adulthood (10-25 years old) were screened from each treatment arm. After 2 annual mass drug administrations, microfilaraemia prevalence in the 2-drug arm was reduced by 54% and 62% in the 2-9 year old and 10-25 year old groups respectively; and corresponding figures for the single-drug arm were 26% and 37%. Though higher reductions were recorded for geometric mean intensity of microfilaraemia in the 2-9 year old groups for both treatment arms, reduction was more pronounced in the 2-drug arm than the single drug arm (74% vs. 24%) in the 10-25 year old group. The reduction in the antigenaemia prevalence in the 2-9 year old group was evident in both treatment arms, but in the 10-25 year old group the reduction was only 16.8% in the 2-drug arm. Our results suggest that the annual, single-dose combination (DEC + ALB) mass treatment regimen has an enhanced effect against bancroftian filariasis compared to single-drug therapy.

Adolescent↗
PubMed2004

Effectiveness of two annual, single-dose mass drug administrations of diethylcarbamazine alone or in combination with albendazole on soil-transmitted helminthiasis in filariasis elimination programme.

A longitudinal community-trial on the control of soil-transmitted helminths (STHs), as part of a lymphatic filariasis elimination campaign, was taken up in two revenue blocks of southern India in the years 2001 and 2002 to assess the impact of two annual single-dose mass drug administration (MDA) of diethylcarbamazine (DEC) + albendazole (ALB) with that of DEC alone. The prevalences and intensities of STHs were studied among cross-sectional samples of school children aged 9-10 years by using the Kato-Katz technique at baseline and 11 months after each MDA. The combined drug mass treatment produced a higher reduction in the prevalence (RIP) (51-77%) and the egg reduction rate (ERR) (92-98%) compared with 12-15% RIP and 58-62% ERR of DEC alone mass treatment. The effect of two-drug therapy after two annual treatments was relatively long lasting as shown by RIP and ERR indicating that the reinfection rates were relatively lower in this approach than single-drug therapy. This study demonstrates that mass drug co-administration of DEC + ALB in Global Programme for Elimination of Lymphatic Filariasis (GPELF) targeted at the community had a synergistic and sustainable effect against soil-transmitted helminthiasis and provided considerable 'beyond filariasis' benefits. The additional advantages accrued to the community underscore the importance of scaling-up GPELF to cover the entire population at risk.

Albendazole↗
PubMed2004

Host-feeding pattern of Culex quinquefasciatus Say and Mansonia annulifera (Theobald) (Diptera: Culicidae), the major vectors of filariasis in a rural area of south India.

Culex quinquefasciatus and Mansonia annulifera are abundant in the rural areas of Kuttanadu, Kerala, India. Bloodmeal identification for individuals of these species collected in this region was determined by the agar-gel precipitin test. A total of 2,328 blood smears from Cx. quinquefasciatus (1,148) and Ma. annulifera (1,180) was tested. Results showed that Cx. quinquefasciatus and Ma. annulifera were highly anthropophilic and that human feeding accounted for 74 and 66% of the total bloodmeals tested. Feeding on cattle accounted for only 1.5 and 2.1% of Cx. quinquefasciatus and Ma. annulifera bloodmeals, respectively. This study showed the high anthropophilic feeding rates of Cx. quinquefasciatus and Ma. annulifera collected from an endemic belt of Malayan filariasis, where epidemiological studies revealed the coexistence of Bancroftian and Malayan filariasis.

Animals↗
PubMed2004

Studies on dengue in rural areas of Kurnool District, Andhra Pradesh, India.

A dengue case was reported for the 1st time in a rural area of Kurnool District, Andhra Pradesh, India. Entomological and serological investigations were carried out to determine the prevalence of dengue vectors and dengue virus. Aedes aegypti was recorded for the 1st time in rural areas of Andhra Pradesh. Breeding of Ae. aegypti was observed only in containers with nonpotable water. Cement cisterns and tanks, stone tubs, and clay pots were the major breeding habitats of Ae. aegypti. Larval indices for Ae. aegypti ranged as follows: house index 28-40%, container index 13-37%, and Breteau index 32-60. A serological survey indicated that humans in Kurnool District have been exposed to dengue virus infections. The potential threat of an outbreak of dengue fever in rural areas because of the prevalence of the vector (Ae. aegypti) and dengue virus is discussed.

Aedes↗
PubMed2003

Longitudinal studies in South Indian villages on Japanese encephalitis virus infection in mosquitoes and seroconversion in goats.

Japanese encephalitis (JE) is endemic in Cuddalore district, Tamil Nadu, where Culex tritaeniorhynchus Giles was the major vector. We screened 45 100 adult female Cx. tritaeniorhynchus (902 pools) by enzyme-linked immunosorbent assay and isolated and confirmed JE virus (JEV) by using an insect bioassay system. We had 69 isolates of which 62 (90%) were identified as JEV. The average vector abundance per man hour for Cx. tritaeniorhynchus was 324.5 per month for the period June 1998-May 2000. The average minimum infection rate (MIR) per month in Cx. tritaeniorhynchus was 1.4 (range 0.0-5.6). Every year, a new batch of goats, 20 in the first year and 31 in the second year, born during the non-JE transmission period (January-June), aged <6 months and negative for haemagglutination inhibition (HI) antibodies were procured and placed in the villages as sentinels. Fortnightly, blood specimens were collected from these goats and tested for JE antibodies by HI test. Seroconversions (SCs) were recorded in 14 goats (70%) in the first year and 23 goats (74%) in the second year. JE HI antibody titres in goats were low (1:10-1:80) and these levels declined to undetectable levels in about 4 weeks following SCs. The time sequence of events indicated that four of five peaks of MIR in mosquitoes were followed 1-3 months later by peaks in the proportion of seroconverted goats. We suggest the screening of goats and cattle as a more feasible tool to stratify areas according to JE infection risk to the human population through the regular health system rather than screening mosquitoes using monoclonal antibodies, which is possible only in specialized laboratories.

Animals↗