P. D. Juyal

Rodents as reservoirs of parasites in India.

We monitored the prevalence of endoparasitic infections of rodents in Punjab State, India, between January 2004 and December 2005. Three species of wild rodents, namely the house rat, Rattus rattus (n= 42), the lesser bandicoot rat, Bandicota bengalensis (n= 34) and the Indian gerbil, Tatera indica (n= 15), were live-captured from houses and crop fields. Examination of various organs revealed that the highest rates of endoparasitic infection occurred in R. rattus (40.5%), followed by B. bengalensis (35.3 %) and then T. indica (20.0%), with an overall infection rate of 35.2%. All three rodent species were found naturally infected with one or more species of helminths. Metacestodes (1-6) of Cysticercus fasciolaris (larvae of Taenia taeniaeformis) were found in all three rodent species (in the liver). In one male T. indica, numerous robust T. taeniaeformis metacestodes were found in oval sacs attached to the mesentery and the abdominal wall, an unusual site. The cauda epididymal fluid of the same gerbil was also found to be infected with a very rare species of strongylid nematode, which could not be identified to genus or species level. It is possible that this nematode is transmitted sexually and thus may affect the reproductive potential of gerbils. This appears to be the first report of this phenomenon. In one B. bengalensis individual, the intestine was found to be obstructed with an acanthocephalan, Moniliformis moniliformis, with concurrent infection with C. fasciolaris in the form of multiple cysts in the liver. Although no natural protozoan infection was found in these field rodents, experimental Trypanosoma evansi infection has been established in all three species with high pathogenicity, and the possibility of sexual transmission was supported by the presence of T. evansi in the cauda epididymal fluid of male rats.

Prevalence and haemato-biochemical profile of Anaplasma marginale infection in dairy animals of Punjab (India).

OBJECTIVE To do the systematic comparison of prevalence of anaplasmosis by PCR and Giemsa stained thin blood smear (GSTBS) based parasitological assays in dairy cattle of Punjab, which has not been reported yet. To analyse the haematobiochemical alterations in infected animals to arrive at the conclusion regarding the pathogenicity induced by Anaplasma marginale (A. marginale) in latent and patent infection. METHODS Study was conducted on 320 animals (236 cows, 62 calves and 22 buffaloes) of Punjab, India. PCR on genome of A. marginale was performed by targeting msp1 β gene using specific primers BAP-2/AL34S, amplifies products of size 407 bp. Questionnaires based data on the characteristics of the infected animals and management strategies of the farm were collected and correlated. RESULTS Higher prevalence and more significant association was observed in the PCR based molecular diagnosis (P=0.00012) as compared to that in GSTBS (P=0.028 8) based diagnosis with various regions under study. With respect to the regions, highest prevalence was recorded in Ferozepur by PCR based diagnosis, while that in Jalandhar by GSTBS examination. Similar marked significant association of the PCR based diagnosis with the age of the animals under study (P=0.00013) was observed elucidating no inverse age resistance to A. marginale in cow calves. Haematobiochemical profile of infected animals revealed marked anemia, liver dysfunction and increase globulin concentrate indicating rise in immunoglobulin level to counteract infection. CONCLUSIONS PCR is far more sensitive in detecting the disease even in latent infection which may act as nidus for spread of anaplasmosis to susceptible animals in endemic areas. Severity of anaemia and liver dysfunction were comparable both in patent as well as latent infection indicating pathogenicity of both.

Molecular Prevalence of Babesia bigemina and Trypanosoma evansi in Dairy Animals from Punjab, India, by Duplex PCR: A Step Forward to the Detection and Management of Concurrent Latent Infections

Specific duplex polymerase chain reaction (PCR) was employed on 411 (386 cattle and 25 buffaloes) blood samples of dairy animals from 9 districts of Punjab, India, for simultaneous detection of Babesia bigemina and Trypanosoma evansi. The results were compared and correlated with conventional Giemsa stained thin blood smear (GSTBS) examination and haematological alterations to know the clinical status and pathogenicity of infections. The Bg3/Bg4 and TR3/TR4 primers were used in duplex PCR for B. bigemina and T. evansi amplified products of 689 bp and 257 bp, respectively. The overall prevalence by duplex PCR was found to be 36.49, 2.43, and 3.41% for T. evansi, B. bigemina, and dual infection, respectively. A more significant difference was observed for dual infection status (P ≤ 0.005) as compared to T. evansi (P ≤ 0.05) and B. bigemina (P ≤ 0.01) among various districts under study. A very low prevalence of T. evansi (0.73%) and B. bigemina (0.48%) was seen by GSTBS. The highly sensitive, specific, and cost-effective duplex PCR was able to detect latent T. evansi and B. bigemina infection in cattle and buffaloes. Haematological evaluation revealed marked pathology in B. bigemina infected group and in dual infected group in contrast to that infected with T. evansi alone.