Rats are the maintenance host for leptospirosis and are the source of the infection to humans and animals. To eradicate leptospirosis, then the maintenance hosts should be eliminated. This is not possible, particularly when it involved wildlife like rats. A good alternative then is to impose biological control on the rat population which is a safe and pragmatic approach. The environment is the indirect source of infection and in tropical countries; recreational areas are often the place foroutbreaks of leptospirosis. Claims that leptospires survive for months in the environment probably is not true. The “top up” or daily excretion of leptospires from the maintenance hosts particularly rats make it appears that the leptospires survived for months in the environment. The good news is that although there are many infected rats in the cities, there were hardly any reports of outbreaks of leptospirosis in urban areas. Outbreaks of leptospirosis tend to be in the countryside particularly in recreational areas, where infection is easily transmitted through the conjunctiva or mucous membrane of the upper respiratory or gastro-intestinal tract through water activities.
A tourist was infected with a new strain of leptospires namely, Leptospira icterohemorrhagiae serovar Lai strain Langkawi, when he was on vacation in Langkawi, Malaysia. The leptospiral strain was successfully isolated from the patient in the Netherland. In this study, the bacteria were retrieved from Holland and inoculated into fifteen guinea pigs in Universiti Putra Malaysia (UPM) to determine its pathogenicity. The main clinical symptoms in the guinea pigs were decreased appetite and jaundice. Blood profile showed high neutrophil, lymphocyte, PCV, RBC, haemoglobin, leukocyte and thrombocyte counts. Besides that, enhancement of electrolytes such as sodium (Na), chloride (Cl), and potassium (K) was also noted. Biochemical examination showed an increase alkaline phosphatase (ALP), aspartate transaminase (AST) and bilirubin levels. Albumin, alanine transaminase (ALT), blood urea, total protein and creatinine were low values. Histopathological examination under haematoxylin and eosin staining showed evidence of haemorrhages, congestion and oedema in all organs, with inflammatory cell infiltration characterized by neutrophils, lymphocytes and macrophages. Hydropic degeneration and cell necrosis were also common in the findings. Leptospires were detected from Day 2 p.i by silver staining and transmission electron microscopy (TEM). Rise in antibody titre was seen as early as Day 5 p.i and leptospiral DNA was detected by PCR in the kidneys and liver on Day 3 and Day 5, respectively. The findings were indicative of leptospirosis. This study demonstrated that guinea pigs are a suitable animal model to illustrate the clinical symptoms and pathological changes seen following infection with Leptospira icterohaemorrhagiae serovar Lai strain Langkawi. In general, the symptoms and changes seen in leptospirosis are similar to viral infections and the information and data from this present study would help differentiate infection due to leptospires from that of viral infection. Leptospiral infection has often been misdiagnosed to be viral infection such as influenza and dengue which have similar signs and symptoms as leptospirosis.
Leptospirosis is re-emerging in Malaysia and many other tropical countries. Its infection of human and animal’s worldwide. The study was carried out to identify predominate Leptospira serovars within rat populations in Kuala Lumpur (KL) by microscopic agglutination test (MAT). As well to investigate the frequency of infection by polymerase chain reaction assays (PCR). The isolated cultures that obtained from culturing kidney tissue of 112 trapped rats from four sites in KL, were identified by MAT using panel of 16 standard hyper immune anti-sera. Besides, identification of Leptospira strains by PCR amplification with G1/G2 and ompL1 Borgpetersenii genes. Results from typing by MAT revealed that 8/57 (7.1%) of cultured isolates reacted against; hyper-immune antisera of serogroup Javanica and 13/57 (22.8%) against serogroup Bataviae. Whereas, the rest of isolates recorded across reactivity 1/20 against serogroups; Icterohaemorrhagiae 2/57, Canicola 1/57, Australis 2/57. From PCR-G1/G2; 50/112 (50.9%) cultures were positive included (40/57 cultures positive to isolation and 10/55 cultures negative to isolation). While, from PCR-ompL1 Borgpetersenii gene; 21/112 (18.7%) cultures positive included (17/57 cultures positive to isolation and 4/55 cultures were negative to isolation). It is obvious from this study that serogroups Javanica and Bataviae were the predominant among rat populations in KL. Also it revealed the high frequency of pathogenic strains among rat populations and their potential risk of humans and animals contracting infection.
Leptospirosis is recognised as one of the leading zoonotic diseases and rodents have been implicated as one of the natural reservoirs of the disease. The Malayan porcupines (Hystrix brachyura) which are also a rodent could possibly be a carrier of leptospiral organisms. This study was conducted to determine the serological prevalence of leptospiral infection among captive Malayan porcupines and to disclose the possibility of porcupines as a reservoir for leptospiral infection. Fifty serum samples were obtained from the Malayan porcupines kept in captivity at the Wildlife Conservation Centre, Sungai Dusun, Malaysia. The microscopic agglutination test (MAT) was performed on the serum samples to detect the presence of agglutinating antibodies to a panel of 16 Leptospira serovars (Australis, Autumnalis, Ballum, Bataviae, Canicola, Celledoni, Djasiman, Hardjobovis, Hardjopratjino, Hebdomadis, Hurstbridge, Icterohaemorrhagiae, Javanica, Pomona, Pyrogenes and Sejroe). From the serological test, 18% (n=9/50) of the Malayan porcupines tested had leptospiral antibodies to serovars Javanica (8%), Hurstbridge (4%), Ballum (2%), Celledoni (2%) and Hardjoprajitno (2%). It is seen that this study disclosed a high prevalence of leptospiral infection in the Malayan porcupines tested and indicated that the Malayan porcupines could possibly be a source of leptospirosis to other animals including humans and that they might play an important role in the epidemiology of leptospiral infection in the country.
Fifteen (15) guinea pigs were experimentally infected with Leptospira icterohemorrhagiae serovar Lai strain
Langkawi, a new strain that was isolated from a human leptospirosis patient. Hematoxylin and Eosin ((H&E) staining
showed haemorrhages, congestion and oedema in all internal organs examined (lungs, liver, spleen and kidneys) with
inflammatory cell infiltration characterized by neutrophils, lymphocytes and macrophages. Hydropic degeneration and
cell necrosis were also common in our findings. Leptospires were detected starting Day 2 p.i by silver staining and
Transmission Electron Microscopy (TEM). Rise in antibody titres started on Day 5 p.i and leptospiral DNA was
detected beginning Day 3 in the kidneys and Day 5 in the liver by Polymerase Chain Reaction (PCR) assay. The
findings illustrated the pathogenesis of leptospirosis in guinea pigs which disclosed them as a suitable animal model for
demonstration of clinical symptoms of leptospirosis and pathological changes after being infected with Leptospira
icterohaemorrhagiae serovar Lai strain Langkawi, particularly pulmonary haemorrhages, a leading cause of mortality
in human leptospirosis.