Group A1: Microbiology (Bacteriology Surveillance)

Title of Study

Surveillance of Leptospiral Serovars in the Philippines


  • Project leaders
    • Dr. Nina G. Gloriani
    • Dr. Shin-ichi Yoshida(KU)
  • Co-Leaders
    • Dr. Yasutake Yanagihara(US)
    • Prof. Lolita L. Cavinta
  • Researchers and Assistants
    • Dr. Kenichiro Iida (KU)
    • Ms. Rubelia Baterna
    • Dr. Sharon Villanueva (KU)
    • Ms. Crystal Amiel Estrada
    • Ms. Ana Kriselda Rivera

General Objective

To identify and characterize the predominant (determine the proportion of prevalent) leptospirae serovars that infect humans and animals in the Philippines

Specific Objectives

To characterize the isolated Leptospirae from humans and animals according to serovars and genotypes

To epidemiologically describe the Leptospirae isolated from humans according to place (urban-rural, upland-lowland), time (season of the year), and person characteristics (age, sex, occupation, place of residence)

To determine the Leptospirae serovars that are pathogenic to animals

Identification of Prevalent Leptospira Serovars in the Philippines

Nina G. Gloriani1, Lolita L. Cavinta1 , Rubelia A. Baterna1 , Crystal Amiel Estrada1, Anna Kriselda Rivera1, Shin-ichi Yoshida2, Sharon Y.A.M. Villanueva2, Yasutake Yanagihara2,
1 Department of Medical Microbiology, College of Public Health, University of the Philippines-Manila,
Manila 1000, Philippines
2 Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan

Leptospirosis is endemic in the Philippines and is one of the reportable infectious diseases in the country. Understanding the epidemiological features of leptospirosis is a critical step in designing intervention for decreasing the risk of transmission. In particular, typing of isolated leptospires is useful in the surveillance of local pathogenic serovars, the recognition of new patterns of disease transmission , the identification of prevalent serovars circulating in our setting that could be used as potential vaccine candidates relevant to our country, as well as in assessing the effectiveness of intervention measures. With the support of Japan International Cooperation Agency (JICA) and the Philippines’ Department of Science and Technology, we conducted studies on the prevalence of Leptospira serovars among patients and high risk groups, as well as animals from the National Capital Region and from three other regions in the Philippines from September 2010 to March 2011. Serovars Manilae , Grippotyphosa, Javanica, and Canicola were isolated from five samples (out of 695 blood and urine samples) collected from humans, using monoclonal antibodies. Among the 10 rat samples collected, 4 were culture positive (urine and kidney), with serovars identified as Manilae and Javanica. All blood samples from dogs were negative by culture, and all water buffalo blood and urine cultures were culture negative. Microscopic agglutination test (MAT) was performed on the human sera, and samples were considered positive if the reactive sera had a titer equal to or greater than 400. The results showed antibodies to serovar Patoc to be the most frequently occurring among National Capital Region patient referrals , followed by Copenhageni and Semaranga , whereas Serovars Poi and Pyrogenes were found to have high prevalence among MAT positive samples from the regional surveillance. These results taken together showed high antibody positivity against serovars that are different from the ones we isolated. The finding that the majority of the serum samples were reactive with Patoc suggests a high exposure to this serovar which is considered non-pathogenic. Additional studies need to be conducted to further characterize the leptospira serovars that are most common in our setting in order to understand better, and address the problem of leptospirosis in the Philippines.