No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
A serosurvey for leptospirosis in North Andaman Indian
... Few seroprevalence studies have been conducted in Andaman during early 1990s. The first reported study was conducted in North Andaman (Sehgal et al., 1994), where outbreaks of Andaman haemorrhagic fever occurred every postmonsoon season. The study estimated a high seroprevalence of 55%, although it was based on a small sample of 58 subjects. ...
Seroprevalence of leptospirosis among a healthy population of the South Andaman Island was assessed through random sampling. Previous studies have high seroprevalences of up to 55% in general population and 65% in agricultural labourers. The study subjects (1,181 in total, 781 rural and 400 urban) were interviewed and tested for antibodies against Leptospira. Multivariate models were developed to determine the risk factors in the rural and the urban population. The overall seroprevalence was 10.9%, with rural (12.9%) being higher than the urban subjects (7.0%). The commonest infecting serogroup was Icterohaemorrhagiae (53.5%), followed by Grippotyphosa (13.2%). Compared to the earlier observation, seroprevalence was lower and an apparent shift in the infecting serogroup was found. This shift was in concordance with the changing trend in animal population. A Significant difference in risk factors, both in rural and urban areas, was also observed. Similar trends in seroprevalence are being observed around the world. Therefore, time to time prevalence studies are needed for the development of effective control measure.
... Many authors have documented outbreaks of Leptospirosis such as from along the coastline of west and southern India and the Andaman Islands [10,11] . Indian prevalence rates are difficult to estimate as concurrent infections maybe present with similar clinical presentations, therefore challenging from a clinical perspective. ...
Objectives: This study was undertaken to correlate the clinical and laboratory findings for both the diseases and gain some understanding in the challenges faced in the interpretation of these findings. Methods: 296 patients with history of fever were tested for dengue and leptospirosis simultaneously using Pan-bio Dengue IgM capture ELISA and Pan-Bio Leptospira IgM ELISA. Based on the test results, the patients were divided into 4 groups and all records studied for comparable clinical and laboratory data. Results: 6.7% of the patients were found to seropositive for both dengue and leptospirosis. Fever, myalgia, headache, jaundice, nausea and vomiting were the commonest presentations accompanied in lower frequency by thrombocytopenia, hepatomegaly and raised transaminases. Hemoconcentration (44.8%) and thrombocytopenia (55.5%) were observed with dengue fever. 10.8% of patients with leptospirosis presented with thrombocytopenia. Other co-infections and underlying conditions included Hepatitis A E and B, enteric fever and complications as Multiorgan failure, Pneumonia and Altered sensorium. Conclusions: Many cofactors such as acute renal failure altered sensorium and severe hemorrhagic episodes were found to be the cause of increasing morbidity and similar clinical presentations which often confounded the judgment for early management. More analysis is required to find the cause of cross-reactivity between the ELISA kits for different infections for use in endemic regions.
... Members of the population at risk acquire this infection from either the environment or animals (14). Serological studies detected anti-leptospiral antibodies in 55% of the healthy population in the North Andaman, Andaman, and Nicobar archipelago (12). High seroprevalence among a healthy population in a hyperendemic area may be the result of asymptomatic infection (2,6). ...
Leptospirosis is an emerging disease around the globe. South Andaman Island is an endemic region for leptospirosis. We herein compared the prevalence of leptospires in urban and rural areas of South Andaman Island. The PCR detection and isolation of Leptospira revealed that pathogenic leptospires were prevalent in sewage water and household drainage water in urban areas and in paddy fields, vegetable field water, and stream water in rural areas. These results demonstrate that intermediates are ubiquitously present in the environment and may be responsible for asymptomatic infections, and also provide an insight into disease ecology.
... This was the first report of leptospirosis with pulmonary involvement from India. Serological studies conducted among healthy individuals in areas affected by the outbreaks showed that a large proportion of the population was seropositive to leptospiral antibodies (Sehgal et al, 1994;. ...
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 hematuria were found in 20%-40% of patients. Distribution of serogroups was studied based on microscopic agglutination test (MAT) titers. The southern zone had all the eleven serogroups in the panel, the eastern zone had nine, the northern zone eight, and the central and western zones had five circulating serogroups each. Among various risk factors studied, rat infestation of houses had the strongest association with leptospiral infection. Many other factors related to the environment, personal and occupational habits, etc, also had significant associations. The study had a few drawbacks. The Task Force has decided to continue the study with modified protocols to generate more accurate and detailed information about disease burden.
Leptospirosis, caused by the genus Leptospira, is one of the most widespread zoonotic diseases with a high prevalence in warm and humid tropical regions. Though it is primarily an infection that affects animals, the recent outbreaks of the disease indicate that it has become an emerging infection in humans. It is a disease known to cause heating up and redness of the hands. A variety of animals, such as rat, mouse, vole, shrew, hedgehog, cattle, pig, and dogs, harbor Leptospira in their convoluted renal tubules. Environmental contamination may reach high levels in areas where carrier animals frequently urinate. Walking barefoot, working in the fields, defecating in open fields, bathing in ponds, crossing stagnant bodies of water on the way to school or workplace, and use of well or stream water for domestic use are among the behavioral risk factors. Location of a home in a low-lying area, presence of ponds near houses, presence of rat infestation, and presence of cattle or dogs in the household are other risk factors for leptospiral infection. All suspected cases should be thoroughly investigated because it is not possible to diagnose the disease with certainty on clinical grounds alone. Antibiotic therapy should be initiated before the fifth day of illness and should not be delayed until the results of the laboratory tests are available. Patients with severe cases should be hospitalized. The indicated dosage is 200 mg of doxycycline orally, once a week and is to be used only in case of short-term exposure. Though antileptospiral vaccines are available in some countries, they are currently used only in individuals employed in certain high-risk jobs. Changes in environmental factors are a prerequisite for long-term prevention of this disease.
Background
Leptospirosis is a zoonotic disease which requires laboratory diagnosis for confirmation.
Materials and Methods
In this study serum samples from adults with acute undifferentiated fever (duration ≤15 days) were tested for IgM antibodies to Leptospira by ELISA, PCR for rrs gene and loop-mediated isothermal amplification (LAMP) assay for LipL32 and LipL41.
Results
Among the 150 sera tested, three were positive by PCR, LAMP and IgM ELISA/modified Faines’ criteria, two by only PCR; seven only by LAMP assay and forty fulfilled modified Faine's criteria (illness clinically compatible and IgM ELISA positive for leptospirosis). Clinical correlation revealed renal compromise, low platelet count and severe jaundice were significantly related to leptospirosis (P < 0.05).
Conclusion
This study suggests that LAMP assay could be useful for diagnosis of leptospirosis during the 1st week of illness whereas IgM ELISA forms the mainstay of diagnosis from the 2nd week onward. Further studies especially community based, comparing ELISA, PCR, LAMP, culture and microscopic agglutination test are required to evaluate the veracity of these findings.
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 the dependent factor and various environmental, occupational and behavioural factors as independent factors. A stratified analysis was also carried out.
The presence of cattle in the house, drinking stream water, contact with garbage, walking barefoot and standing in water while working were identified as significant factors associated with leptospirosis. Stratified analysis showed a dose response relationship between number of cattle in the house and the risk of leptospiral infection suugesting that cattle could be a source of infection.
Identification of the potential risk factors would help understand the transmission dynamics of the disease and formulate public health interventions.
The LEPTO Dipstick assay is a newly developed test for the diagnosis of leptospirosis and uses a broadly reactive antigen for detecting IgM antibodies. The test was evaluated in the Andaman and Nicobar Islands, using 867 serum samples from known cases of leptospirosis and controls. The efficacy of IgM ELISA was also tested for comparison. The LEPTO Dipstick had a sensitivity of 78.7%, a specificity of 88.3% and a positive predictive value of 91.0%. The test had a good level of agreement with the standard criteria for diagnosis using paired microscopic agglutination tests (kappa = 0.64). These indices were similar to those of IgM ELISA (sensitivity 78.5%, specificity 87.6%, positive predictive value 90.5%, kappa 0.63). Both the LEPTO Dipstick and IgM ELISA had the highest sensitivity during the second, third and fourth weeks of illness (87.6% and 88.2%, respectively). Sensitivities during the first week and after 4 weeks were relatively low but acceptable. The test is very easy to perform and does not require any special skills for its performance. The reagents and dipsticks have a long shelf-life even at room temperature. As the test can be performed without the aid of sophisticated equipment, it is suitable for use at the peripheral level as a rapid screening test for the diagnosis of leptospirosis.
Leptospirosis occurs as seasonal outbreaks, lasting for about 3 weeks during October-November in North Andaman. A randomized controlled trial was undertaken to assess the efficacy of doxycycline prophylaxis in the prevention of infection and clinical disease due to leptospires during the outbreak period. A sample population of 782 persons, randomized into two groups was given doxycycline 200 mg/week and a placebo. The microscopic agglutination test was done on blood samples collected on day zero, after 6 weeks and after 12 weeks. Infection rates and attack rates of clinical illness were calculated in the two groups based on the serological results. Statistically there was no difference in the infection rates among the two groups. However, a statistically significant difference was observed in the clinical disease attack rates (3.11 vs. 6.82%) between study group and control group. The results of the study indicate that doxycycline prophylaxis does not prevent leptospiral infection in an endemic area, but has a significant protective effect in reducing the morbidity and mortality during outbreaks.
ResearchGate has not been able to resolve any references for this publication.