A.P. Sugunan - Academia.edu (original) (raw)

Papers by A.P. Sugunan

Research paper thumbnail of Additional file 1 of Detection of Nipah virus in Pteropus medius in 2019 outbreak from Ernakulam district, Kerala, India

Additional file 1: Supplementary Figure 1. Alignment between the reference Nipah virus retrieved ... more Additional file 1: Supplementary Figure 1. Alignment between the reference Nipah virus retrieved from human sequence of Bangladesh, India, 2004 (Accession Number: AY988601.1) and the bat samples of the Kerala, India, 2019. The figure was created in the CLC-genomics Workbench version 20.0.4. The genes encoded are marked in violet color and the green color display the proteins encoded by the reference NiV sequence. The quality scores are marked as the probability that ranges form 0–100% below each of the retrieved NiV sequences.

Research paper thumbnail of Communication Correspondence

Leptospirosis is a major public health problem in Andaman Islands. Several strains of Leptospira ... more Leptospirosis is a major public health problem in Andaman Islands. Several strains of Leptospira have been isolated from the Andamans over the years. Leptospires isolated recently from human cases were compared with one of the earliest available isolates from these islands, dating back to 1929, to study their serological and genetic relatedness. Randomly amplified polymorphic DNA (RAPD) fingerprints of the isolates, generatedwith a primer used previously to differentiate between Leptospira species and serovars, revealed that some of the recent isolateswere genetically identical to the 1929 isolate. The antigenic properties of these strains, as revealed by microscopic agglutination tests with group-specific rabbit antisera and mAbs, were also similar. These findings suggest that a Leptospira strain originally isolated in 1929 has possibly persisted in these islands for over 70 years and continues to cause acute leptospirosis in humans.

Research paper thumbnail of Status of hepatitis B infection - a decade after hepatitis B vaccination of susceptible Nicobarese, an indigenous tribe of Andaman & Nicobar (A&N) islands with high hepatitis B endemicity

The Indian Journal of Medical Research, 2015

Background & objectives: Andaman and Nicobar Islands of India, home to six primitive tribes, cons... more Background & objectives: Andaman and Nicobar Islands of India, home to six primitive tribes, constituting about 10 per cent of the total population of these Islands have been detected with high endemicity of hepatitis B infection. During 2000, a total of 936 individuals ≤ 45 yr, negative for hepatitis B surface antigen (HBsAg) and antibody anti-HBs were vaccinated with three doses of a recombinant DNA hepatitis B vaccine in two villages of Car Nicobar Islands. The present study was undertaken to evaluate the impact of the hepatitis B vaccination with respect to the persistence of antibodies and incidence of new infections, prevalence of surface gene mutations among the Nicobarese community in the two villages ten years after hepatitis B vaccination. Methods: Follow up samples were collected from 211 individuals who had received three doses of vaccine ten years back and from a control group of 515 non-vaccinated individuals. The HBsAg, anti-HBs and anti-HBc assay results were compare...

Research paper thumbnail of Antimicrobial resistance in Shigella – rapid increase in frequency and widening of spectrum in Andaman Islands, India

F1000Research, 2012

Shigellosis is known to be a major cause of acute childhood diarrhoea in Andaman &amp... more Shigellosis is known to be a major cause of acute childhood diarrhoea in Andaman & Nicobar Islands, India. Rapid emergence of antibiotic resistance warrants continuous monitoring of sensitivity pattern of bacterial isolates. We report here the salient findings of an ongoing study on shigellosis in Andaman Islands, India, with regards to change in drug resistance pattern during the past one decade. During 2006-2009, stools samples from 412 paediatric diarrhoea patients were collected and processed for isolation and identification of Shigella spp. Susceptibility to 22 antimicrobial drugs was tested and MICs were determined for 3 rd generation cephalosporins, quinolones, amoxicillin-clavulanic acid combination and gentamicin. Drug susceptibility pattern of these isolates were compared with that of 33 isolates obtained during 2000-2002. Shigella isolates were recovered from 50 of 412 stool samples processed. Resistance to ampicillin, nalidixic acid, tetracycline and ciprofloxacin was observed in 100, 96, 94 and 82 per cent of the isolates, respectively. The frequency of resistance to these drugs was significantly (P<0.001) higher than that observed during 2000-2002. Resistance to seven drugs was observed in 2000-2002, whereas resistance to 21 drugs was seen during 2006-2009. The number of drug resistance pattern increased from 13 in 2000-2002 to 43 in 2006-2009. Resistance to newer generation fluoroquinolones, 3 rd generation cephalosporins and augmentin, which was not observed during 2000-2002, appeared during 2006-2009. The frequency of resistance among Shigella isolates has increased substantially between 2000-2002 and 2006-2009 and the spectrum of resistance has widened. At present, the option for antimicrobial therapy in shigellosis in Andaman is limited to a small number of drugs. Continuous local monitoring of resistance patterns is necessary for the appropriate selection of empirical antimicrobial therapy.

Research paper thumbnail of Detection of Nipah virus in Pteropus medius in 2019 outbreak from Ernakulam district, Kerala, India

BMC Infectious Diseases, 2021

Background In June 2019, Nipah virus (NiV) infection was detected in a 21-year-old male (index ca... more Background In June 2019, Nipah virus (NiV) infection was detected in a 21-year-old male (index case) of Ernakulum, Kerala, India. This study was undertaken to determine if NiV was in circulation in Pteropus species (spp) in those areas where the index case had visit history in 1 month. Methods Specialized techniques were used to trap the Pteropus medius bats (random sampling) in the vicinity of the index case area. Throat and rectal swabs samples of 141 bats along with visceral organs of 92 bats were collected to detect the presence of NiV by real-time reverse transcriptase-polymerase chain reaction (qRTPCR). Serum samples of 52 bats were tested for anti-NiV Immunoglobulin (Ig) G antibodies by Enzyme-Linked Immunosorbent Assay (ELISA). The complete genome of NiV was sequenced by next-generation sequencing (NGS) from the tissues and swab samples of bats. Results One rectal swab sample and three bats visceral organs were found positive for the NiV. Interestingly, 20.68% (12/58) of Pte...

Research paper thumbnail of Impact of Temperature Variant on Survival of Aedes albopictus Skuse (Diptera: Culicidae): Implications on Thermotolerance and Acclimation

Neotropical Entomology, 2019

Research paper thumbnail of Outbreak Investigation of Nipah Virus Disease in Kerala, India, 2018

The Journal of Infectious Diseases, 2018

Research paper thumbnail of Little Andaman Island, a new focus of infection with nocturnally periodic Wuchereria bancrofti

The Indian journal of medical research, 1996

A filariasis survey was carried out for the first time in the Little Andaman island, covering a p... more A filariasis survey was carried out for the first time in the Little Andaman island, covering a population of 12,247 in 12 of the 13 villages. Infection due to Wuchereria bancrofti was found only in 3 villages with microfilaria (mf) rate ranging from 1.02 to 6.45 per cent. Observations on the appearance of mf in peripheral blood showed that the parasite is nocturnally periodic form with a peak at 2000 h. The infection was prevalent only among the settlers from Bihar and Bangladesh and none of the local tribal population was affected. Carriers included 18 males and 4 females. Their age ranged from 6 to 50 yr. Only one of 2788 individuals examined was found to have clinical manifestation. A total of 442 female mosquitoes belonging to eight species were collected and dissected. Natural infection was found only in Culex quinquefasciatus (0.24%). Epidemiological investigations and vector studies indicates local transmission. Thus, this island appears as a new focus of infection.

Research paper thumbnail of Community-centred approach for the control of Aedes spp. in a peri-urban zone in the Andaman and Nicobar Islands using temephos

The National medical journal of India

Chikungunya fever struck the Andaman and Nicobar Islands in July 2006. From the entomological poi... more Chikungunya fever struck the Andaman and Nicobar Islands in July 2006. From the entomological point of view, dengue and chikungunya are hard to control due to the high prevalence of Aedes aegypti in both urban and rural areas. Mobilizing communities for the control of Aedes aegypti has not been attempted in India. We did a prospective observational feasibility study in one peri-urban locality (Brookshabad) to assess the Aedes spp. infestation and subsequently test the efficacy of a community-based approach to control Aedes aegypti. An Aedes infestation larval survey was done with the assistance of community volunteers using the single larval survey (SLS) technique. House index, container index and Breteau index reflecting the relative prevalence and infestation levels were estimated. Various information, education and communication (IEC) campaign tools were developed to disseminate information about the prevalent situation. Several talks were organized to sensitize and motivate the ...

Research paper thumbnail of Leptospirosis disease burden estimation and surveillance networking in India

The Southeast Asian journal of tropical medicine and public health, 2003

Although leptospirosis is known to have occurred in India since the early years of the 20th centu... more Although leptospirosis is known to have occurred in India since the early years of the 20th century, no accurate data on disease burden exist. During the past two decades, leptospirosis cases have been reported with increasing frequency from different parts of the country. Several large outbreaks have occurred. In the year 2000, the Indian Council of Medical Research set up a Task Force on Leptospirosis. The Task Force conducted a multicentric study on disease burden due to leptospirosis. As part of the study, 3,682 patients with acute febrile illness, from 13 different centers in India, were investigated for the presence of current leptospiral infection using the Lepto-dipstick test. Of these patients, 469 (12.7%) were found to have leptospiral infection. The positivity rate ranged from 3.27% in the central zone to 28.16% in the southern zone. Fever, body aches and chills were the common symptoms observed. Urinary abnormalities, such as oliguria, yellow discoloration of urine and h...

Research paper thumbnail of Nutritional deficiency disorders and high mortality among children of the Great Andamanese tribe

The National medical journal of India

The population of the Great Andamanese tribe of the Andaman Islands has been declining at a rapid... more The population of the Great Andamanese tribe of the Andaman Islands has been declining at a rapid pace. The case fatality rate during a recent outbreak of dysentery was 30.8%, all the deaths being among under-fives. As malnutrition is known to potentiate susceptibility to death due to infectious diseases, we undertook a study to determine the prevalence of malnutrition among the Great Andamanese tribe and its role in contributing to the high mortality among them due to infectious diseases. The study included a diet survey, nutritional anthropometry, clinical examination, haemoglobin estimation and stool examination for intestinal parasitic infestations. Information was also collected about every pregnancy in all ever-married women in the community and deaths of their children. All 36 members of the tribe were covered. The Andamanese had a poor intake of iron, vitamin A and riboflavin but a good intake of energy, protein and fats. More than 85% of the children below 6 years were unde...

Research paper thumbnail of Outbreak of leptospirosis with pulmonary involvement in north Andaman

The Indian journal of medical research, 1995

An outbreak of acute febrile illness with haemorrhagic manifestations and pulmonary involvement o... more An outbreak of acute febrile illness with haemorrhagic manifestations and pulmonary involvement occurred in Diglipur of North Andaman during October-November 1993. Investigations were carried out to see whether leptospires were responsible for this outbreak. Serum samples were collected from suspected cases and tested for presence of antibodies to leptospires by microscopic agglutination test (MAT) using a battery of 19 antigens representing 16 serogroups. 66.7 per cent of the specimens showed significant titres of antibodies against leptospires, 18 of 23 paired sera (78.3%) showed sero-conversion or four-fold rise in antibody titres. The commonest serovar involved was Leptospira grippotyphosa followed by L. canicola and L. JEZ bratislava. In 7 patients L. grippotyphosa was the sole serovar against which antibodies were detected. Clinical and epidemiological observations of this outbreak were similar with that of earlier seasonal outbreaks of acute febrile illness with haemorrhagic ...

Research paper thumbnail of A 22-mer primer enhances discriminatory power of AP-PCR fingerprinting technique in characterization of leptospires

Tropical Medicine and International Health, 2004

Research paper thumbnail of Molecular tracking of the lineage of strains of Vibrio cholerae O1 biotype El Tor associated with a cholera outbreak in Andaman and Nicobar Islands, India

Tropical Medicine and International Health, 2005

A large outbreak of acute watery diarrhoea involving all age groups of mongoloid tribal aborigine... more A large outbreak of acute watery diarrhoea involving all age groups of mongoloid tribal aborigines occurred during October-November, 2002 in the Nancowry group of Andaman and Nicobar Islands in the Indian Ocean. Twenty-one of the 67 stool samples from 67 patients were positive for toxigenic Vibrio cholerae O1, serotype Ogawa biotype El Tor, which showed striking similarity in its antibiogram with some of the strains of V. cholerae O1 Serotype Ogawa biotype El Tor isolated in Kolkata. The Nancowry and Kolkata isolates were compared with molecular tools involving random amplified polymorphic DNA (RAPD) fingerprinting, ribotyping and pulsed-field gel electrophoresis (PFGE). RAPD fingerprinting and ribotyping techniques revealed that all the V. cholerae strains associated with the outbreak in these islands were clonal in nature and identical to a population of isolates obtained from Kolkata since 1993. PFGE could discriminate within these Kolkata isolates further and established that a particular subtype of this population reached the remote Nancowry islands and was responsible for the outbreak.

Research paper thumbnail of Leptospirosis in the Andaman Islands, India

Transactions of the Royal Society of Tropical Medicine and Hygiene, 2008

Leptospirosis is an emerging zoonosis. In the Andaman Islands during the early twentieth century,... more Leptospirosis is an emerging zoonosis. In the Andaman Islands during the early twentieth century, it occurred in the penal settlements of the British India Administration, mostly as Weil's disease, an acute febrile illness with hepato-renal complications. It was caused by leptospires belonging to groups Akiamy A and Andamans A. After the 1930s nothing further is known regarding the disease until the late 1980s, when Andaman haemorrhagic fever (AHF), a mysterious illness with the majority of cases presenting pulmonary involvement, appeared. AHF was later identified as leptospirosis and severe pulmonary haemorrhage was shown for the first time as a complication of leptospirosis from India. Leptospirosis continues to occur in the Islands annually. It generally presents as two separate clinical syndromes: the hepato-renal form, and the pulmonary form, which is associated with high case fatality rates ranging from 10 to 15%. Infections are due to a variety of serovars, Valbuzzi being the commonest. Leptospira interrogans sensu stricto has been the predominant infecting species. Doxycycline has been shown to confer a beneficial effect in reducing the clinical illness and mortality during outbreaks. The history of leptospirosis in the Islands, its epidemiology, clinical spectrum, characteristics of the isolates and control are reviewed and discussed in this article.

Research paper thumbnail of A clone of Leptospira interroganssensu stricto is the major cause of leptospirosis in the archipelago of Andaman and Nicobar Islands, India

Letters in Applied Microbiology, 2005

Andaman and Nicobar Islands in India has a century long history of human leptospirosis. Several i... more Andaman and Nicobar Islands in India has a century long history of human leptospirosis. Several isolates have been recovered over the years from different locations. The present study was undertaken to understand the clonal relationship between all these pathogenic leptospires recovered from these islands. Arbitrarily primed polymerase chain reaction (AP-PCR) was employed to genetically characterize 40 isolates recovered during 1995--2001 and their fingerprints were compared with those of 26 reference strains of known genetic and serological affinities. Sequences of PCR-amplified products from representative isolates were compared with those of different strains belonging to seven genospecies. AP-PCR fingerprints revealed that 32 of the 40 isolates were clonal in nature and fingerprints of all the isolates matched with known reference strains of pathogenic Leptospira interrogans sensu stricto. Comparison of sequence data of PCR amplified products of reference strains and isolates also corroborated these findings. The study revealed that 80% of the isolates recovered from these islands were clonal in nature and all the isolates taken in the study belonged to Leptospira interrogans sensu stricto. An extension of the study in animal population would help in understanding the transmission dynamics of this commonly circulating clone in these islands, which in turn might help in effective control of this public health problem.

Research paper thumbnail of Percutaneous exposure resulting in laboratory-acquired leptospirosis – a case report

Journal of Medical Microbiology, 2004

A screw-capped glass tube containing a Leptospira culture accidentally broke and the laboratory w... more A screw-capped glass tube containing a Leptospira culture accidentally broke and the laboratory worker who was handling the tube sustained a cut on his hand. The wound was flooded with the culture. The culture was that of strain MG 347 belonging to serovar Australis recovered from a patient, and it had undergone 52 passages in Ellinghausen McCullough Johnson Harris medium. The laboratory worker developed a headache 21 days after the accident and became febrile the next day. He was hospitalized for 5 days and was treated initially with doxycycline and later with ciprofloxacin. A blood sample collected on the second day of illness, after starting doxycycline therapy, yielded leptospires and the isolate, HZ 651, was identified as serovar Australis. Monoclonal antibody patterns and randomly amplified polymorphic DNA fingerprinting patterns of the isolate and strain MG 347 were identical, thus indicating that HZ 651 and MG 347 were clonal.

Research paper thumbnail of Field application of Lepto lateral flow for rapid diagnosis of leptospirosis

Journal of Medical Microbiology, 2003

Research paper thumbnail of Investigations on possible role of MIF gene polymorphism in progression of chikungunya infection into cases of acute flaccid paralysis and chronic arthropathy

Journal of Genetics, 2009

Research paper thumbnail of Leptospirosis among schoolchildren of the Andaman & Nicobar Islands, India: low levels of morbidity and mortality among pre-exposed children during an epidemic

Epidemiology and Infection, 2004

Leptospirosis is an important public health problem in the Andaman Islands. The disease is being ... more Leptospirosis is an important public health problem in the Andaman Islands. The disease is being increasingly reported among children and adolescents in recent times. An attempt was made to find out the level of exposure to leptospires, to estimate the incidence of infection and to identity the risk factors for acquiring infection among children. A sample of 1544 schoolchildren was selected. Presence of anti-leptospiral antibodies was tested using the microscopic agglutination test (MAT). Students were interviewed for behavioural factors. In total, 341 (221 seronegative and 120 seropositive) students were followed up clinically and serologically during a subsequent outbreak. An overall seropositivity rate of 23·6% (95% CI 21·54–25·81) was observed. Infection rate was 33·5% among seronegatives whereas re-infection rate was 16·7% among seropositives during the outbreak that occurred 1 month after the first sample collection. Morbidity and mortality were found to be higher among serone...

Research paper thumbnail of Additional file 1 of Detection of Nipah virus in Pteropus medius in 2019 outbreak from Ernakulam district, Kerala, India

Additional file 1: Supplementary Figure 1. Alignment between the reference Nipah virus retrieved ... more Additional file 1: Supplementary Figure 1. Alignment between the reference Nipah virus retrieved from human sequence of Bangladesh, India, 2004 (Accession Number: AY988601.1) and the bat samples of the Kerala, India, 2019. The figure was created in the CLC-genomics Workbench version 20.0.4. The genes encoded are marked in violet color and the green color display the proteins encoded by the reference NiV sequence. The quality scores are marked as the probability that ranges form 0–100% below each of the retrieved NiV sequences.

Research paper thumbnail of Communication Correspondence

Leptospirosis is a major public health problem in Andaman Islands. Several strains of Leptospira ... more Leptospirosis is a major public health problem in Andaman Islands. Several strains of Leptospira have been isolated from the Andamans over the years. Leptospires isolated recently from human cases were compared with one of the earliest available isolates from these islands, dating back to 1929, to study their serological and genetic relatedness. Randomly amplified polymorphic DNA (RAPD) fingerprints of the isolates, generatedwith a primer used previously to differentiate between Leptospira species and serovars, revealed that some of the recent isolateswere genetically identical to the 1929 isolate. The antigenic properties of these strains, as revealed by microscopic agglutination tests with group-specific rabbit antisera and mAbs, were also similar. These findings suggest that a Leptospira strain originally isolated in 1929 has possibly persisted in these islands for over 70 years and continues to cause acute leptospirosis in humans.

Research paper thumbnail of Status of hepatitis B infection - a decade after hepatitis B vaccination of susceptible Nicobarese, an indigenous tribe of Andaman & Nicobar (A&N) islands with high hepatitis B endemicity

The Indian Journal of Medical Research, 2015

Background & objectives: Andaman and Nicobar Islands of India, home to six primitive tribes, cons... more Background & objectives: Andaman and Nicobar Islands of India, home to six primitive tribes, constituting about 10 per cent of the total population of these Islands have been detected with high endemicity of hepatitis B infection. During 2000, a total of 936 individuals ≤ 45 yr, negative for hepatitis B surface antigen (HBsAg) and antibody anti-HBs were vaccinated with three doses of a recombinant DNA hepatitis B vaccine in two villages of Car Nicobar Islands. The present study was undertaken to evaluate the impact of the hepatitis B vaccination with respect to the persistence of antibodies and incidence of new infections, prevalence of surface gene mutations among the Nicobarese community in the two villages ten years after hepatitis B vaccination. Methods: Follow up samples were collected from 211 individuals who had received three doses of vaccine ten years back and from a control group of 515 non-vaccinated individuals. The HBsAg, anti-HBs and anti-HBc assay results were compare...

Research paper thumbnail of Antimicrobial resistance in Shigella – rapid increase in frequency and widening of spectrum in Andaman Islands, India

F1000Research, 2012

Shigellosis is known to be a major cause of acute childhood diarrhoea in Andaman &amp... more Shigellosis is known to be a major cause of acute childhood diarrhoea in Andaman & Nicobar Islands, India. Rapid emergence of antibiotic resistance warrants continuous monitoring of sensitivity pattern of bacterial isolates. We report here the salient findings of an ongoing study on shigellosis in Andaman Islands, India, with regards to change in drug resistance pattern during the past one decade. During 2006-2009, stools samples from 412 paediatric diarrhoea patients were collected and processed for isolation and identification of Shigella spp. Susceptibility to 22 antimicrobial drugs was tested and MICs were determined for 3 rd generation cephalosporins, quinolones, amoxicillin-clavulanic acid combination and gentamicin. Drug susceptibility pattern of these isolates were compared with that of 33 isolates obtained during 2000-2002. Shigella isolates were recovered from 50 of 412 stool samples processed. Resistance to ampicillin, nalidixic acid, tetracycline and ciprofloxacin was observed in 100, 96, 94 and 82 per cent of the isolates, respectively. The frequency of resistance to these drugs was significantly (P<0.001) higher than that observed during 2000-2002. Resistance to seven drugs was observed in 2000-2002, whereas resistance to 21 drugs was seen during 2006-2009. The number of drug resistance pattern increased from 13 in 2000-2002 to 43 in 2006-2009. Resistance to newer generation fluoroquinolones, 3 rd generation cephalosporins and augmentin, which was not observed during 2000-2002, appeared during 2006-2009. The frequency of resistance among Shigella isolates has increased substantially between 2000-2002 and 2006-2009 and the spectrum of resistance has widened. At present, the option for antimicrobial therapy in shigellosis in Andaman is limited to a small number of drugs. Continuous local monitoring of resistance patterns is necessary for the appropriate selection of empirical antimicrobial therapy.

Research paper thumbnail of Detection of Nipah virus in Pteropus medius in 2019 outbreak from Ernakulam district, Kerala, India

BMC Infectious Diseases, 2021

Background In June 2019, Nipah virus (NiV) infection was detected in a 21-year-old male (index ca... more Background In June 2019, Nipah virus (NiV) infection was detected in a 21-year-old male (index case) of Ernakulum, Kerala, India. This study was undertaken to determine if NiV was in circulation in Pteropus species (spp) in those areas where the index case had visit history in 1 month. Methods Specialized techniques were used to trap the Pteropus medius bats (random sampling) in the vicinity of the index case area. Throat and rectal swabs samples of 141 bats along with visceral organs of 92 bats were collected to detect the presence of NiV by real-time reverse transcriptase-polymerase chain reaction (qRTPCR). Serum samples of 52 bats were tested for anti-NiV Immunoglobulin (Ig) G antibodies by Enzyme-Linked Immunosorbent Assay (ELISA). The complete genome of NiV was sequenced by next-generation sequencing (NGS) from the tissues and swab samples of bats. Results One rectal swab sample and three bats visceral organs were found positive for the NiV. Interestingly, 20.68% (12/58) of Pte...

Research paper thumbnail of Impact of Temperature Variant on Survival of Aedes albopictus Skuse (Diptera: Culicidae): Implications on Thermotolerance and Acclimation

Neotropical Entomology, 2019

Research paper thumbnail of Outbreak Investigation of Nipah Virus Disease in Kerala, India, 2018

The Journal of Infectious Diseases, 2018

Research paper thumbnail of Little Andaman Island, a new focus of infection with nocturnally periodic Wuchereria bancrofti

The Indian journal of medical research, 1996

A filariasis survey was carried out for the first time in the Little Andaman island, covering a p... more A filariasis survey was carried out for the first time in the Little Andaman island, covering a population of 12,247 in 12 of the 13 villages. Infection due to Wuchereria bancrofti was found only in 3 villages with microfilaria (mf) rate ranging from 1.02 to 6.45 per cent. Observations on the appearance of mf in peripheral blood showed that the parasite is nocturnally periodic form with a peak at 2000 h. The infection was prevalent only among the settlers from Bihar and Bangladesh and none of the local tribal population was affected. Carriers included 18 males and 4 females. Their age ranged from 6 to 50 yr. Only one of 2788 individuals examined was found to have clinical manifestation. A total of 442 female mosquitoes belonging to eight species were collected and dissected. Natural infection was found only in Culex quinquefasciatus (0.24%). Epidemiological investigations and vector studies indicates local transmission. Thus, this island appears as a new focus of infection.

Research paper thumbnail of Community-centred approach for the control of Aedes spp. in a peri-urban zone in the Andaman and Nicobar Islands using temephos

The National medical journal of India

Chikungunya fever struck the Andaman and Nicobar Islands in July 2006. From the entomological poi... more Chikungunya fever struck the Andaman and Nicobar Islands in July 2006. From the entomological point of view, dengue and chikungunya are hard to control due to the high prevalence of Aedes aegypti in both urban and rural areas. Mobilizing communities for the control of Aedes aegypti has not been attempted in India. We did a prospective observational feasibility study in one peri-urban locality (Brookshabad) to assess the Aedes spp. infestation and subsequently test the efficacy of a community-based approach to control Aedes aegypti. An Aedes infestation larval survey was done with the assistance of community volunteers using the single larval survey (SLS) technique. House index, container index and Breteau index reflecting the relative prevalence and infestation levels were estimated. Various information, education and communication (IEC) campaign tools were developed to disseminate information about the prevalent situation. Several talks were organized to sensitize and motivate the ...

Research paper thumbnail of Leptospirosis disease burden estimation and surveillance networking in India

The Southeast Asian journal of tropical medicine and public health, 2003

Although leptospirosis is known to have occurred in India since the early years of the 20th centu... more Although leptospirosis is known to have occurred in India since the early years of the 20th century, no accurate data on disease burden exist. During the past two decades, leptospirosis cases have been reported with increasing frequency from different parts of the country. Several large outbreaks have occurred. In the year 2000, the Indian Council of Medical Research set up a Task Force on Leptospirosis. The Task Force conducted a multicentric study on disease burden due to leptospirosis. As part of the study, 3,682 patients with acute febrile illness, from 13 different centers in India, were investigated for the presence of current leptospiral infection using the Lepto-dipstick test. Of these patients, 469 (12.7%) were found to have leptospiral infection. The positivity rate ranged from 3.27% in the central zone to 28.16% in the southern zone. Fever, body aches and chills were the common symptoms observed. Urinary abnormalities, such as oliguria, yellow discoloration of urine and h...

Research paper thumbnail of Nutritional deficiency disorders and high mortality among children of the Great Andamanese tribe

The National medical journal of India

The population of the Great Andamanese tribe of the Andaman Islands has been declining at a rapid... more The population of the Great Andamanese tribe of the Andaman Islands has been declining at a rapid pace. The case fatality rate during a recent outbreak of dysentery was 30.8%, all the deaths being among under-fives. As malnutrition is known to potentiate susceptibility to death due to infectious diseases, we undertook a study to determine the prevalence of malnutrition among the Great Andamanese tribe and its role in contributing to the high mortality among them due to infectious diseases. The study included a diet survey, nutritional anthropometry, clinical examination, haemoglobin estimation and stool examination for intestinal parasitic infestations. Information was also collected about every pregnancy in all ever-married women in the community and deaths of their children. All 36 members of the tribe were covered. The Andamanese had a poor intake of iron, vitamin A and riboflavin but a good intake of energy, protein and fats. More than 85% of the children below 6 years were unde...

Research paper thumbnail of Outbreak of leptospirosis with pulmonary involvement in north Andaman

The Indian journal of medical research, 1995

An outbreak of acute febrile illness with haemorrhagic manifestations and pulmonary involvement o... more An outbreak of acute febrile illness with haemorrhagic manifestations and pulmonary involvement occurred in Diglipur of North Andaman during October-November 1993. Investigations were carried out to see whether leptospires were responsible for this outbreak. Serum samples were collected from suspected cases and tested for presence of antibodies to leptospires by microscopic agglutination test (MAT) using a battery of 19 antigens representing 16 serogroups. 66.7 per cent of the specimens showed significant titres of antibodies against leptospires, 18 of 23 paired sera (78.3%) showed sero-conversion or four-fold rise in antibody titres. The commonest serovar involved was Leptospira grippotyphosa followed by L. canicola and L. JEZ bratislava. In 7 patients L. grippotyphosa was the sole serovar against which antibodies were detected. Clinical and epidemiological observations of this outbreak were similar with that of earlier seasonal outbreaks of acute febrile illness with haemorrhagic ...

Research paper thumbnail of A 22-mer primer enhances discriminatory power of AP-PCR fingerprinting technique in characterization of leptospires

Tropical Medicine and International Health, 2004

Research paper thumbnail of Molecular tracking of the lineage of strains of Vibrio cholerae O1 biotype El Tor associated with a cholera outbreak in Andaman and Nicobar Islands, India

Tropical Medicine and International Health, 2005

A large outbreak of acute watery diarrhoea involving all age groups of mongoloid tribal aborigine... more A large outbreak of acute watery diarrhoea involving all age groups of mongoloid tribal aborigines occurred during October-November, 2002 in the Nancowry group of Andaman and Nicobar Islands in the Indian Ocean. Twenty-one of the 67 stool samples from 67 patients were positive for toxigenic Vibrio cholerae O1, serotype Ogawa biotype El Tor, which showed striking similarity in its antibiogram with some of the strains of V. cholerae O1 Serotype Ogawa biotype El Tor isolated in Kolkata. The Nancowry and Kolkata isolates were compared with molecular tools involving random amplified polymorphic DNA (RAPD) fingerprinting, ribotyping and pulsed-field gel electrophoresis (PFGE). RAPD fingerprinting and ribotyping techniques revealed that all the V. cholerae strains associated with the outbreak in these islands were clonal in nature and identical to a population of isolates obtained from Kolkata since 1993. PFGE could discriminate within these Kolkata isolates further and established that a particular subtype of this population reached the remote Nancowry islands and was responsible for the outbreak.

Research paper thumbnail of Leptospirosis in the Andaman Islands, India

Transactions of the Royal Society of Tropical Medicine and Hygiene, 2008

Leptospirosis is an emerging zoonosis. In the Andaman Islands during the early twentieth century,... more Leptospirosis is an emerging zoonosis. In the Andaman Islands during the early twentieth century, it occurred in the penal settlements of the British India Administration, mostly as Weil's disease, an acute febrile illness with hepato-renal complications. It was caused by leptospires belonging to groups Akiamy A and Andamans A. After the 1930s nothing further is known regarding the disease until the late 1980s, when Andaman haemorrhagic fever (AHF), a mysterious illness with the majority of cases presenting pulmonary involvement, appeared. AHF was later identified as leptospirosis and severe pulmonary haemorrhage was shown for the first time as a complication of leptospirosis from India. Leptospirosis continues to occur in the Islands annually. It generally presents as two separate clinical syndromes: the hepato-renal form, and the pulmonary form, which is associated with high case fatality rates ranging from 10 to 15%. Infections are due to a variety of serovars, Valbuzzi being the commonest. Leptospira interrogans sensu stricto has been the predominant infecting species. Doxycycline has been shown to confer a beneficial effect in reducing the clinical illness and mortality during outbreaks. The history of leptospirosis in the Islands, its epidemiology, clinical spectrum, characteristics of the isolates and control are reviewed and discussed in this article.

Research paper thumbnail of A clone of Leptospira interroganssensu stricto is the major cause of leptospirosis in the archipelago of Andaman and Nicobar Islands, India

Letters in Applied Microbiology, 2005

Andaman and Nicobar Islands in India has a century long history of human leptospirosis. Several i... more Andaman and Nicobar Islands in India has a century long history of human leptospirosis. Several isolates have been recovered over the years from different locations. The present study was undertaken to understand the clonal relationship between all these pathogenic leptospires recovered from these islands. Arbitrarily primed polymerase chain reaction (AP-PCR) was employed to genetically characterize 40 isolates recovered during 1995--2001 and their fingerprints were compared with those of 26 reference strains of known genetic and serological affinities. Sequences of PCR-amplified products from representative isolates were compared with those of different strains belonging to seven genospecies. AP-PCR fingerprints revealed that 32 of the 40 isolates were clonal in nature and fingerprints of all the isolates matched with known reference strains of pathogenic Leptospira interrogans sensu stricto. Comparison of sequence data of PCR amplified products of reference strains and isolates also corroborated these findings. The study revealed that 80% of the isolates recovered from these islands were clonal in nature and all the isolates taken in the study belonged to Leptospira interrogans sensu stricto. An extension of the study in animal population would help in understanding the transmission dynamics of this commonly circulating clone in these islands, which in turn might help in effective control of this public health problem.

Research paper thumbnail of Percutaneous exposure resulting in laboratory-acquired leptospirosis – a case report

Journal of Medical Microbiology, 2004

A screw-capped glass tube containing a Leptospira culture accidentally broke and the laboratory w... more A screw-capped glass tube containing a Leptospira culture accidentally broke and the laboratory worker who was handling the tube sustained a cut on his hand. The wound was flooded with the culture. The culture was that of strain MG 347 belonging to serovar Australis recovered from a patient, and it had undergone 52 passages in Ellinghausen McCullough Johnson Harris medium. The laboratory worker developed a headache 21 days after the accident and became febrile the next day. He was hospitalized for 5 days and was treated initially with doxycycline and later with ciprofloxacin. A blood sample collected on the second day of illness, after starting doxycycline therapy, yielded leptospires and the isolate, HZ 651, was identified as serovar Australis. Monoclonal antibody patterns and randomly amplified polymorphic DNA fingerprinting patterns of the isolate and strain MG 347 were identical, thus indicating that HZ 651 and MG 347 were clonal.

Research paper thumbnail of Field application of Lepto lateral flow for rapid diagnosis of leptospirosis

Journal of Medical Microbiology, 2003

Research paper thumbnail of Investigations on possible role of MIF gene polymorphism in progression of chikungunya infection into cases of acute flaccid paralysis and chronic arthropathy

Journal of Genetics, 2009

Research paper thumbnail of Leptospirosis among schoolchildren of the Andaman & Nicobar Islands, India: low levels of morbidity and mortality among pre-exposed children during an epidemic

Epidemiology and Infection, 2004

Leptospirosis is an important public health problem in the Andaman Islands. The disease is being ... more Leptospirosis is an important public health problem in the Andaman Islands. The disease is being increasingly reported among children and adolescents in recent times. An attempt was made to find out the level of exposure to leptospires, to estimate the incidence of infection and to identity the risk factors for acquiring infection among children. A sample of 1544 schoolchildren was selected. Presence of anti-leptospiral antibodies was tested using the microscopic agglutination test (MAT). Students were interviewed for behavioural factors. In total, 341 (221 seronegative and 120 seropositive) students were followed up clinically and serologically during a subsequent outbreak. An overall seropositivity rate of 23·6% (95% CI 21·54–25·81) was observed. Infection rate was 33·5% among seronegatives whereas re-infection rate was 16·7% among seropositives during the outbreak that occurred 1 month after the first sample collection. Morbidity and mortality were found to be higher among serone...