Prevalence and risk factors of feline leukaemia virus and feline immunodeficiency virus in peninsular Malaysia

BACKGROUND

Feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) are major causes of morbidity and mortality in domestic and wild felids. Despite the clinical importance of feline retroviruses and the growing interest in cats as pets, information about FeLV and FIV in Malaysia is presently insufficient to properly advise veterinarians and pet owners. A cross-sectional study was carried out from January 2010 to December 2010 to determine the prevalence and risk factors associated with FeLV and FIV among domestic cats in peninsular Malaysia. Plasma samples were harvested from the blood of 368 domestic cats and screened for evidence of FeLV p27 antigen and FIV antibodies, using an immunochromatographic kit. Additionally, data on cat demographics and health were collected using a structured questionnaire, and were evaluated as potential risk factors for FeLV or FIV status.

RESULTS

Of the 368 cats that were evaluated in this study, 12.2% (45/368; 95% CI = 8.88 - 15.58) were positive for FeLV p27 antigen, 31.3%, (115/368; 95% CI = 26.51 - 35.99) were seropositive to FIV antibodies, and 4.3% (16/368; 95% CI = 2.27 - 6.43) had evidence of both viruses. Factors found to significantly increase the risk for FeLV seropositivity include sex, age, behaviour, sickness, and living in a multi-cat household. Seropositive response to FIV was significantly associated with sex, neuter status, age, behaviour, and health status.

CONCLUSIONS

The present study indicates that FeLV and FIV are common among domestic cats in peninsular Malaysia, and that factors related to cat demographics and health such as age, sex, behaviour, health status and type of household are important predictors for seropositive status to FeLV or FIV in peninsular Malaysia. High prevalence of FeLV or FIV observed in our study is of concern, in view of the immunosuppressive potentials of the two pathogens. Specific measures for control and prevention such as screening and routine vaccination are needed to ensure that FeLV and FIV are controlled in the cat population of peninsular Malaysia.

Ultrastructure of Felis catus whole fetus (Fcwf-4) cell culture following infection with feline coronavirus

Feline coronavirus (FCoV) consists of two biotypes based on their growth in cell culture and their antigenicity. Infections with FCoV are highly prevalent in the cat population worldwide. In this study, Felis catus whole fetus (Fcwf-4)cell culture was infected with FCoV UPM11C/08. Virus multiplication in cell culture was monitored and examined under the transmission electron microscope. The virus particles revealed the characteristic morphology of feline FCoV represented by envelope viruses surrounded by peplomers. Virus attachment and entry into the cell occurred 15 h post-infection (pi), and the myriad of virus particles were observed both extracellularly and intracellularly after 48 h pi. Thereafter, intracellular virus particles were observed to be present in vacuoles or present freely in the cytoplasm.

Diagnostic methods for feline coronavirus: a review

Feline coronaviruses (FCoVs) are found throughout the world. Infection with FCoV can result in a diverse range of signs from clinically inapparent infections to a highly fatal disease called feline infectious peritonitis (FIP). FIP is one of the most serious viral diseases of cats. While there is neither an effective vaccine, nor a curative treatment for FIP, a diagnostic protocol for FCoV would greatly assist in the management and control of the virus. Clinical findings in FIP are non-specific and not helpful in making a differential diagnosis. Haematological and biochemical abnormalities in FIP cases are also non-specific. The currently available serological tests have low specificity and sensitivity for detection of active infection and cross-react with FCoV strains of low pathogenicity, the feline enteric coronaviruses (FECV). Reverse transcriptase polymerase chain reaction (RT-PCR) has been used to detect FCoV and is rapid and sensitive, but results must be interpreted in the context of clinical findings. At present, a definitive diagnosis of FIP can be established only by histopathological examination of biopsies. This paper describes and compares diagnostic methods for FCoVs and includes a brief account of the virus biology, epidemiology, and pathogenesis.