Chandika D. Gamage

Prevalence and carrier status of leptospirosis in smallholder dairy cattle and peridomestic rodents in Kandy, Sri Lanka.

Leptospirosis is an important bacterial zoonotic disease globally and one of the notifiable diseases in Sri Lanka. Other than human leptospirosis, little information is available on leptospirosis in domestic and feral animals in Sri Lanka. Thus, this study attempted to determine the prevalence and carrier status of leptospirosis in smallholder dairy cattle and peridomestic rodents to understand the impact of the disease on public health in Kandy, Sri Lanka. Cattle and rodent samples were collected from the Yatinuwara and Udunuwara divisional secretaries in Kandy. Serum samples were analyzed for the presence of antileptospiral antibodies using microscopic agglutination test. DNA was extracted from cattle urine and rodent kidney tissue samples, in which polymerase chain reaction was carried out to detect the Leptospira flaB gene. The cattle in 19 (38.8%) of the 49 farms harbored antileptospiral antibodies. Out of 113 cattle serum samples, 23 (20.3%) were positive; 17 (73.9%) and 6 (26.1%) reacted with serogroups Sejroe and Hebdomadis, respectively. Out of the 74 rodent samples, 13 (17.5%) were positive; 8 (61.5%) and 4 (30.8%) had reactions to serogroups Javanica and Icterohaemorrhagiae, respectively. Leptospiral DNA was detected in one cattle urine sample and identified as Leptospira interrogans. This study revealed a high prevalence of leptospirosis in cattle and rodents in Kandy. These animals were infected with a wide array of leptospiral serogroups, which are consistent with the research findings observed in humans in Kandy. Overall, serological data indicate that relative to rodents, cattle may be a more significant reservoir for human transmission and a greater source of potential risk to local agricultural communities.

Rapid, whole blood diagnostic test for detecting anti-hantavirus antibody in rats.

Hantavirus is a causative agent of rodent-borne viral zoonoses, hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome. Seoul virus (SEOV) is a causative agent of urban and laboratory rat-associated HFRS worldwide. Surveillance of rodents has been done mainly by serological detection of hantavirus-specific antibodies by enzyme linked immunosorbent assay (ELISA) and immunofluorescent antibody assay (IFA). An immunochromatographic (ICG) test was developed with the N-terminal 103 amino acids of nucleocapsid protein of Hantaan virus expressed by Escherichia coli as an antigen to detect IgG antibody specific to hantavirus in sera from Rattus sp. animals. Antibody-detecting sensitivity of the ICG test was the same as that of ELISA and about 100-times higher than that of IFA. Overall sensitivities and specificities of the ICG test in comparison to ELISA and IFA for sera from 192 urban rats and 123 laboratory rats were 99.3% and 100%, respectively. Diluted whole blood samples without separation could be used for the ICG test. The ICG test enabled detection of antibodies to SEOV, Hantaan, Dobrava/Belgrade, and Thailand viruses, which are causative agents of HFRS throughout Eurasia. The ICG test is a rapid, simple and safe method for diagnosis of SEOV infection in rats.

Religious leaders as potential advocates for HIV/AIDS prevention among the general population in Sri Lanka

Abstract Religious leaders in Sri Lanka may have a high potential of contributing to HIV/AIDS prevention among the general public because of their social status. In order to assess their current HIV/AIDS-related knowledge and attitude and the possibility of becoming community advocates of HIV/AIDS prevention, we conducted a questionnaire survey among Buddhist, Hindu, Muslim and Christian leaders in Sri Lanka in 2009. There were limited correct responses about HIV/AIDS-related knowledge and attitudes toward people living with HIV/AIDS (PLHIV), and information regarding condoms, HIV testing and counselling were poorly understood. Although a condom was less acceptable as a part of HIV/AIDS prevention, they were willing to learn more about HIV/AIDS and expressed support for both PLHIV and HIV prevention activities. Their experiences, preparedness and willingness of HIV prevention activities were associated with age, knowledge and/or religious background. In conclusion, intensive and systematic learning opportunities should be provided to equip the religious leaders with overall HIV/AIDS knowledge to become key players for HIV/AIDS prevention in their communities.

Development of an immunochromatography strip test based on truncated nucleocapsid antigens of three representative hantaviruses

BackgroundHantaviruses are causative agents of hemorrhagic fever with renal syndrome (HFRS) and nephropathia epidemica (NE) in the Old World and hantavirus pulmonary syndrome (HPS) in the New World. There is a need for time-saving diagnostic methods. In the present study, recombinant N antigens were used as antigens in an immunochromatography strip (ICG) test to detect specific IgG antibodies.MethodsThe N-terminal 103 amino acids (aa) of Hantaan virus (HTNV), Puumala virus (PUUV) and Andes virus (ANDV) nucleocapsid (N) protein were expressed in E. coli as representative antigens of three groups (HFRS, NE and HPS-causing viruses) of hantavirus. Five different types of ICG test strips, one antigen line on one strip for each of the three selected hantaviruses (HTNV, PUUV and ANDV), three antigen lines on one strip and a mixed antigen line on one strip, were developed and sensitivities were compared.ResultsA total of 87 convalescent-phase patient sera, including sera from 35 HFRS patients, 36 NE patients and 16 HPS patients, and 25 sera from healthy seronegative people as negative controls were used to evaluate the ICG test. Sensitivities of the three-line strip and mixed-line strip were similar to those of the single antigen strip (97.2 to 100%). On the other hand, all of the ICG test strips showed high specificities to healthy donors.ConclusionThese results indicated that the ICG test with the three representative antigens is an effective serodiagnostic tool for screening and typing of hantavirus infection in humans.

Epidemiology, Surveillance and Laboratory Diagnosis of Leptospirosis in the WHO South-East Asia Region

Leptospirosis is a serious spirochete zoonotic disease of increasing worldwide prevalence and distribution (Bharti et al., 2003; Levett, 2001). The disease especially occurs in tropical areas with high rainfall and severe human cases may cause multi-organ failure leading to death. The World Health Organization (WHO) has estimated that approximately 10-100 cases per 100,000 people are infected annually in tropics (WHO, 2003). Although leptospirosis has been recognized for many years, it is considered a re-emerging disease of humans in many regions, exemplified by recent outbreaks in Brazil (Romero et al., 2003), India (Chaudhry et al., 2002), Malaysia (Sejvar et al., 2003), Nicaragua (Ashford et al., 2000; Trevejo et al., 1998), Sri Lanka (Epidemiology Unit-Sri Lanka, 2009a) and Thailand (Thaipadungpanit et al., 2007). It also causes substantial domestic livestock losses annually (Faine et al., 1999).

Intraspecific phylogeny of the house shrews, Suncus murinus-S. montanus species complex, based on the mitochondrial cytochrome b gene

Abstract. A phylogenetic tree was reconstructed based on the mitochondrial cytochrome b gene nucleotide sequences of 169 individuals of house shrews (Suncus murinus and S. montanus) from 44 localities in East Asia, Southeast Asia, West Asia, and islands in the western Indian Ocean. Shrews from China (Zhejiang), Japan (Okinawa), Vietnam, and Indonesia (Java) formed a monophyletic group with less genetic variation. Therefore, the shrews of these regions appeared to have originated from one or a few localities. Contrary to this, shrews from Sri Lanka, Myanmar, and Pakistan consisted of several haplogroups. This finding suggests immigration movements to these areas. Fascinating findings were also obtained concerning the islands in the western Indian Ocean. First, shrews on Zanzibar Island (Tanzania) had almost the same haplotype as those in southwestern Iran. Therefore, the house shrew in Zanzibar may have immigrated from Iran (or vice versa). Second, shrews from Madagascar and Grande Comore Island shared the same haplotype, whereas the shrews on Réunion Island were clearly different from those of Madagascar and Comoros. Thus, there appears to have been several immigration routes to the islands of the western Indian Ocean.