A survey was carried out among the rural and urban settlers and two tribal groups viz. Nicobarese... more A survey was carried out among the rural and urban settlers and two tribal groups viz. Nicobarese and Onges, of Andaman and Nicobar islands. The survey covered preschool school aged children and adults. Out of the total 1,384 stool samples examined, 652 (47.1%) showed ova or cysts of one or more intestinal parasites. Among the preschool children, Nicobarese showed the highest overall prevalence rate (80.5%) followed by urban (46.7%) and rural (38.6%) preschool children. Ascaris lumbricoides was the commonest form of parasite encountered in all the groups of preschool children, followed by Trichuris trichura. While ascariasis and trichuriasis were more common among the urban children than in rural children, giardiasis was more common among the rural preschool children. The school age children among rural settlers showed an overall prevalence rate of 61.1% which was significantly higher than that among the rural preschool children. Among the school age children also, ascariasis was th...
The Andaman & Nicobar Islands, situated in the Bay of Bengal, is an Union Territory of In... more The Andaman & Nicobar Islands, situated in the Bay of Bengal, is an Union Territory of India. Health care in these islands (population of about 3 50 000) is almost entirely provided by the Government. GB Pant Hospital, located at Port Blair, is the only referral hospital in the ...
Leptospirosis outbreaks occur frequently in North and South Andaman Islands but not in Middle And... more Leptospirosis outbreaks occur frequently in North and South Andaman Islands but not in Middle Andaman. In 2002, an outbreak appeared in Middle Andaman for the first time. Although a study on risk factors was conducted in North Andaman, it used seropositivity to define leptospirosis. Since seropositivity might not indicate current leptospiral infection and as no study on risk factors was conducted in Middle Andaman, we carried out this study to identify the risk factors during the outbreak. A suspected outbreak of leptospirosis occurred in Rangat of Middle Andaman during October - November 2002. Suspected cases were screened for leptospirosis using microscopic agglutination test (MAT). Fifty two patients confirmed to have leptospirosis based on rising titres in MAT on paired sera, and 104 age, sex and neighbourhood seronegative matched controls, were included in the study. A conditional multiple regression by backward elimination process was carried out with acute leptospirosis as th...
The Southeast Asian journal of tropical medicine and public health, 2003
The incidence of leptospirosis in human beings has been increasing in recent years. Early diagnos... more The incidence of leptospirosis in human beings has been increasing in recent years. Early diagnosis and treatment can prevent complications and reduce mortality. The conventional laboratory methods for diagnosis rely on the demonstration of leptospires in clinical specimens, recovering the organisms in culture or the demonstration of antibodies to leptospires. Demonstration techniques have low sensitivity and specificity. Leptospires grow slowly and the positivity rate in culture is very low. Although microscopic agglutination test has been the cornerstone of serological diagnosis, the procedure is complex. New tests, like ELISA, dipstick test, lateral flow, etc, are relatively simple and rapid, but sensitivity is low during the early stages of the disease. The cross agglutination absorption test (CAAT) and typing with monoclonal antibodies (MCA) are the techniques used for serological characterization. These techniques are complicated and might not help in the case of certain serog...
Early diagnosis is the key to the treatment of leptospirosis. For development of rapid diagnostic... more Early diagnosis is the key to the treatment of leptospirosis. For development of rapid diagnostic kits, a thorough knowledge about the nature of the proteins expressed by the pathogen during infection is necessary. The present study was undertaken to understand the nature of immunoreactive proteins from commonly circulating serogroups of Leptospira in the endemic Andaman and Nicobar Islands, India. Proteins were extracted from six strains of Leptospira representing five different serogroups following four different preparation methods, viz., whole cell lysis by sonication, detergent solubilization, outer and inner membrane isolations, and were subsequently characterized on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Immunoblots were made from the sonicated proteins using hyperimmune rabbit antisera, homologous and heterologous patient sera separately. The 67, 65, 45, 43, 35, 32 and 18 kDa major proteins in the whole cell lysate were common among all the fi...
Making a diagnosis on the results of a single microscopic agglutination test (MAT) is difficult b... more Making a diagnosis on the results of a single microscopic agglutination test (MAT) is difficult because of the uncertainties about the cut-off titre. The present study was conducted to determine the significant titre for a single MAT in areas of high and low endemicity for leptospirosis. A total of 1944 serum samples were collected from healthy individuals and confirmed patients residing in areas of high and low endemicity. All the sera were screened by MAT using 10 live leptospiral strains as antigens. From the distribution of titres among healthy individuals and in patients, the sensitivity and specificity at different cut-off titres were calculated. Likelihood ratio positive (LR+), likelihood ratio negative (LR-), and LR+/LR- were calculated. Receiver operating characteristics (ROC) curves were plotted for the early and late stages of the disease in both the areas. The ROC plot was totally below the no benefit line during the first week of illness in high endemic area. During the...
Although darkground microscopy (DGM) is the method employed for examining the growth of leptospir... more Although darkground microscopy (DGM) is the method employed for examining the growth of leptospires in culture, it is not useful for diagnosis when used directly on body fluids. However, it continues to be used as a method for diagnosing leptospirosis in many centres in India. The present study was undertaken to evaluate the diagnostic accuracy of DGM by comparing it with established tests like culture, microscopic agglutination test (MAT), IgM ELISA and Lepto-Dipstick. A total of 170 patients clinically suspected to have leptospirosis were included in the study. The gold standard for diagnosis was positive blood culture, or seroconversion, or a four-fold rise in titre in MAT. DGM was done on plasma after centrifugation at 1000 g and 3000 g and on serum. Indices of accuracy including sensitivity, specificity, predictive values and kappa value of agreement with the gold standard diagnostic criteria were calculated. DGM had a sensitivity of 40.2 per cent, specificity of 61.5 per cent,...
In an attempt to understand the clinical spectrum and pathological and biochemical abnormalities ... more In an attempt to understand the clinical spectrum and pathological and biochemical abnormalities and their prognostic importance in leptospirosis, a prospective study was carried out in Port Blair during September 1996 to August 1997. Out of 80 patients suspected to have leptospirosis, 58 were proved to have current leptospiral infection using serological tests and among these, 14 died giving a case fatality rate of 24.1 per cent. The incidence of the disease showed two separate peaks roughly coinciding with the paddy sowing and harvesting season and the majority of the patients had history of exposure to wet and water logged environment prior to the attack of the disease. The disease presented as two separate clinical syndromes--the hepato-renal form and the pulmonary form though some degree of overlap was present. Hepatic and renal complications occurred in 30 patients each with 26 of them having both. These generally occurred late in the course of the disease and the mortality ra...
A total of 237 Nicobarese subjects who had received hepatitis B vaccination as part of mass vacci... more A total of 237 Nicobarese subjects who had received hepatitis B vaccination as part of mass vaccination project during 2000-2001 were screened for anti-HBsAg titres by quantitative ELISA five years after vaccination. Anti-HBsAg antibody was estimated using quantitative ELISA. Proportion of the subjects with protective levels of antibody and geometric mean antibody titres were calculated. Among the 237 study subjects, 213 had received three doses of vaccine, 17 had received two doses and seven had received one dose. The geometric mean titres of anti-HBs antibodies were 201.7, 31.9 and 23.1 mIU/ml among those who received three, two and one dose of vaccine, respectively. Among those who received three doses of vaccination, 85.9 per cent had anti-HBs antibody levels of 10 mIU/ml or more, indicating seroprotection. The difference in the seroprotection rates among those who received three doses of vaccination (85.9%) and those who received less than three doses (58.3%) was significant. S...
ObjectivesA study was conducted among the Onge tribe of the Andaman and Nicobar Islands with the ... more ObjectivesA study was conducted among the Onge tribe of the Andaman and Nicobar Islands with the objectives of identifying demographic factors responsible for the decline in their population and assessing their nutritional status, which is an important determinant of child survival.Study design and subjectsThe study included estimation of indices of fertility and child mortality, and assessment of nutritional status. All individuals of the Onge community settled on Little Andaman Island were included.ResultsThe mean total marital fertility rate was estimated to be 5.15 live births per woman and the general fertility rate was 200 live births per 1000 married-woman-years. Although the gross reproduction rate was estimated to be 2.2 female children per married woman, the net reproduction rate was only 0.9 surviving female child per married woman. The mean infant mortality rate during the past 30 years was 192.7 per 1000 live births, and the child survival rate was found to be only 53.2...
Nineteen isolates of leptospires recovered from patients during three epidemics that occurred at ... more Nineteen isolates of leptospires recovered from patients during three epidemics that occurred at different places and different times in the Andaman Islands and eight isolates from sporadic cases were characterized using serological and molecular genetic techniques. Group sera and monoclonal antibodies were used for antigenic characterization, whereas fluorescent amplified fragment length polymorphism (FAFLP) was used for genotyping. Of the 27 isolates, 19 were identified as belonging to serogroup Grippotyphosa, 3 belonged to serogroup Australis, 2 belonged to serogroup Icterohaemorrhagiae, and 1 each belonged to serogroups Hebdomadis, Canicola, and Sejroe. Analysis of FAFLP data grouped these 27 isolates into two main clusters of genotypes. One of the clusters, populated by 19 isolates, included 16 outbreak isolates. Seven of these 19 isolates belonged to serovar Ratnapura, 10 belonged to serovar Valbuzzi, and 1 each belonged to serovar Grippotyphosa and serovar Saxkoebing. Of the ...
A survey was carried out among the rural and urban settlers and two tribal groups viz. Nicobarese... more A survey was carried out among the rural and urban settlers and two tribal groups viz. Nicobarese and Onges, of Andaman and Nicobar islands. The survey covered preschool school aged children and adults. Out of the total 1,384 stool samples examined, 652 (47.1%) showed ova or cysts of one or more intestinal parasites. Among the preschool children, Nicobarese showed the highest overall prevalence rate (80.5%) followed by urban (46.7%) and rural (38.6%) preschool children. Ascaris lumbricoides was the commonest form of parasite encountered in all the groups of preschool children, followed by Trichuris trichura. While ascariasis and trichuriasis were more common among the urban children than in rural children, giardiasis was more common among the rural preschool children. The school age children among rural settlers showed an overall prevalence rate of 61.1% which was significantly higher than that among the rural preschool children. Among the school age children also, ascariasis was th...
The Andaman & Nicobar Islands, situated in the Bay of Bengal, is an Union Territory of In... more The Andaman & Nicobar Islands, situated in the Bay of Bengal, is an Union Territory of India. Health care in these islands (population of about 3 50 000) is almost entirely provided by the Government. GB Pant Hospital, located at Port Blair, is the only referral hospital in the ...
Leptospirosis outbreaks occur frequently in North and South Andaman Islands but not in Middle And... more Leptospirosis outbreaks occur frequently in North and South Andaman Islands but not in Middle Andaman. In 2002, an outbreak appeared in Middle Andaman for the first time. Although a study on risk factors was conducted in North Andaman, it used seropositivity to define leptospirosis. Since seropositivity might not indicate current leptospiral infection and as no study on risk factors was conducted in Middle Andaman, we carried out this study to identify the risk factors during the outbreak. A suspected outbreak of leptospirosis occurred in Rangat of Middle Andaman during October - November 2002. Suspected cases were screened for leptospirosis using microscopic agglutination test (MAT). Fifty two patients confirmed to have leptospirosis based on rising titres in MAT on paired sera, and 104 age, sex and neighbourhood seronegative matched controls, were included in the study. A conditional multiple regression by backward elimination process was carried out with acute leptospirosis as th...
The Southeast Asian journal of tropical medicine and public health, 2003
The incidence of leptospirosis in human beings has been increasing in recent years. Early diagnos... more The incidence of leptospirosis in human beings has been increasing in recent years. Early diagnosis and treatment can prevent complications and reduce mortality. The conventional laboratory methods for diagnosis rely on the demonstration of leptospires in clinical specimens, recovering the organisms in culture or the demonstration of antibodies to leptospires. Demonstration techniques have low sensitivity and specificity. Leptospires grow slowly and the positivity rate in culture is very low. Although microscopic agglutination test has been the cornerstone of serological diagnosis, the procedure is complex. New tests, like ELISA, dipstick test, lateral flow, etc, are relatively simple and rapid, but sensitivity is low during the early stages of the disease. The cross agglutination absorption test (CAAT) and typing with monoclonal antibodies (MCA) are the techniques used for serological characterization. These techniques are complicated and might not help in the case of certain serog...
Early diagnosis is the key to the treatment of leptospirosis. For development of rapid diagnostic... more Early diagnosis is the key to the treatment of leptospirosis. For development of rapid diagnostic kits, a thorough knowledge about the nature of the proteins expressed by the pathogen during infection is necessary. The present study was undertaken to understand the nature of immunoreactive proteins from commonly circulating serogroups of Leptospira in the endemic Andaman and Nicobar Islands, India. Proteins were extracted from six strains of Leptospira representing five different serogroups following four different preparation methods, viz., whole cell lysis by sonication, detergent solubilization, outer and inner membrane isolations, and were subsequently characterized on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Immunoblots were made from the sonicated proteins using hyperimmune rabbit antisera, homologous and heterologous patient sera separately. The 67, 65, 45, 43, 35, 32 and 18 kDa major proteins in the whole cell lysate were common among all the fi...
Making a diagnosis on the results of a single microscopic agglutination test (MAT) is difficult b... more Making a diagnosis on the results of a single microscopic agglutination test (MAT) is difficult because of the uncertainties about the cut-off titre. The present study was conducted to determine the significant titre for a single MAT in areas of high and low endemicity for leptospirosis. A total of 1944 serum samples were collected from healthy individuals and confirmed patients residing in areas of high and low endemicity. All the sera were screened by MAT using 10 live leptospiral strains as antigens. From the distribution of titres among healthy individuals and in patients, the sensitivity and specificity at different cut-off titres were calculated. Likelihood ratio positive (LR+), likelihood ratio negative (LR-), and LR+/LR- were calculated. Receiver operating characteristics (ROC) curves were plotted for the early and late stages of the disease in both the areas. The ROC plot was totally below the no benefit line during the first week of illness in high endemic area. During the...
Although darkground microscopy (DGM) is the method employed for examining the growth of leptospir... more Although darkground microscopy (DGM) is the method employed for examining the growth of leptospires in culture, it is not useful for diagnosis when used directly on body fluids. However, it continues to be used as a method for diagnosing leptospirosis in many centres in India. The present study was undertaken to evaluate the diagnostic accuracy of DGM by comparing it with established tests like culture, microscopic agglutination test (MAT), IgM ELISA and Lepto-Dipstick. A total of 170 patients clinically suspected to have leptospirosis were included in the study. The gold standard for diagnosis was positive blood culture, or seroconversion, or a four-fold rise in titre in MAT. DGM was done on plasma after centrifugation at 1000 g and 3000 g and on serum. Indices of accuracy including sensitivity, specificity, predictive values and kappa value of agreement with the gold standard diagnostic criteria were calculated. DGM had a sensitivity of 40.2 per cent, specificity of 61.5 per cent,...
In an attempt to understand the clinical spectrum and pathological and biochemical abnormalities ... more In an attempt to understand the clinical spectrum and pathological and biochemical abnormalities and their prognostic importance in leptospirosis, a prospective study was carried out in Port Blair during September 1996 to August 1997. Out of 80 patients suspected to have leptospirosis, 58 were proved to have current leptospiral infection using serological tests and among these, 14 died giving a case fatality rate of 24.1 per cent. The incidence of the disease showed two separate peaks roughly coinciding with the paddy sowing and harvesting season and the majority of the patients had history of exposure to wet and water logged environment prior to the attack of the disease. The disease presented as two separate clinical syndromes--the hepato-renal form and the pulmonary form though some degree of overlap was present. Hepatic and renal complications occurred in 30 patients each with 26 of them having both. These generally occurred late in the course of the disease and the mortality ra...
A total of 237 Nicobarese subjects who had received hepatitis B vaccination as part of mass vacci... more A total of 237 Nicobarese subjects who had received hepatitis B vaccination as part of mass vaccination project during 2000-2001 were screened for anti-HBsAg titres by quantitative ELISA five years after vaccination. Anti-HBsAg antibody was estimated using quantitative ELISA. Proportion of the subjects with protective levels of antibody and geometric mean antibody titres were calculated. Among the 237 study subjects, 213 had received three doses of vaccine, 17 had received two doses and seven had received one dose. The geometric mean titres of anti-HBs antibodies were 201.7, 31.9 and 23.1 mIU/ml among those who received three, two and one dose of vaccine, respectively. Among those who received three doses of vaccination, 85.9 per cent had anti-HBs antibody levels of 10 mIU/ml or more, indicating seroprotection. The difference in the seroprotection rates among those who received three doses of vaccination (85.9%) and those who received less than three doses (58.3%) was significant. S...
ObjectivesA study was conducted among the Onge tribe of the Andaman and Nicobar Islands with the ... more ObjectivesA study was conducted among the Onge tribe of the Andaman and Nicobar Islands with the objectives of identifying demographic factors responsible for the decline in their population and assessing their nutritional status, which is an important determinant of child survival.Study design and subjectsThe study included estimation of indices of fertility and child mortality, and assessment of nutritional status. All individuals of the Onge community settled on Little Andaman Island were included.ResultsThe mean total marital fertility rate was estimated to be 5.15 live births per woman and the general fertility rate was 200 live births per 1000 married-woman-years. Although the gross reproduction rate was estimated to be 2.2 female children per married woman, the net reproduction rate was only 0.9 surviving female child per married woman. The mean infant mortality rate during the past 30 years was 192.7 per 1000 live births, and the child survival rate was found to be only 53.2...
Nineteen isolates of leptospires recovered from patients during three epidemics that occurred at ... more Nineteen isolates of leptospires recovered from patients during three epidemics that occurred at different places and different times in the Andaman Islands and eight isolates from sporadic cases were characterized using serological and molecular genetic techniques. Group sera and monoclonal antibodies were used for antigenic characterization, whereas fluorescent amplified fragment length polymorphism (FAFLP) was used for genotyping. Of the 27 isolates, 19 were identified as belonging to serogroup Grippotyphosa, 3 belonged to serogroup Australis, 2 belonged to serogroup Icterohaemorrhagiae, and 1 each belonged to serogroups Hebdomadis, Canicola, and Sejroe. Analysis of FAFLP data grouped these 27 isolates into two main clusters of genotypes. One of the clusters, populated by 19 isolates, included 16 outbreak isolates. Seven of these 19 isolates belonged to serovar Ratnapura, 10 belonged to serovar Valbuzzi, and 1 each belonged to serovar Grippotyphosa and serovar Saxkoebing. Of the ...
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Papers by A.P. Sugunan