Exotic pets bring disease risk

According to Finance Ministry trade statistics, Japan imports more than a million animals every year, excluding small animals, insects and fish.

Rodents comprise 30 percent to 40 percent and reptiles 50 percent to 60 percent of that total.

A Health, Labor and Welfare Ministry research team on infectious diseases spread by imported animals, led by Tokyo Univ. Prof. Yasuhiro Yoshikawa, has found that many rodents and reptiles carry dangerous diseases.

Yumi Une, assistant professor of Azabu University, and some other members of the research team found after studying 512 rodents of 26 species from fiscal 2003 to fiscal 2005 that 36 of them from 12 species carried leptospira--which can cause fever, jaundice and inflammation of the kidneys.

Leptospira, which can be detected in animal urine tests, infects humans through the skin and mucus membranes. There have been examples of the agent causing epidemics in foreign countries, and there have been documented outbreaks in Japan in the past. Une points out that it is especially troublesome that five out of seven arboreal rodents surveyed had leptospira.

"An arboreal rodent usually climbs to a high point in its cage to urinate, and this could spread leptospira outside the cage," Une said.

For example, two employees of a trading firm in Shizuoka were infected with leptospira and hospitalized for jaundice and blood in their urine after the company imported southern flying squirrels from April to June 2005.

Many rodents from the Americas carry giardia, a parasitic worm that causes diarrhea. For example, 93 percent of degus studied were found to have the worm. According to the research by Une's team, 168 rodents of 19 species, or 33 percent of the rodents examined, had staphylococcus aureus bacteria, and many from Asia carried salmonella.

The health ministry started in September a measure based on the Infectious Diseases Law to stipulate that individuals and corporations when importing animals need a veterinary certificate issued by the exporting country certifying the creature poses no risk to humans.

The measure covered animals previously unregulated by measures, including measures that prohibited imports of animals that may cause serious infectious diseases and that stipulate import inspections of dogs, cats and monkeys under the Rabies Prevention Law and the Infectious Diseases Law.

Under the new measure, which stipulates that only rodents born and raised at designated facilities can be imported, wild rodents cannot be imported due to the risk of them carrying diseases.

However, pygmy jerboa, which are difficult to breed, and chipmunks, which can be found in the wild, are among animals imported. "When they think a veterinary certificate is dubious, the government should question the exporting country or send people to the country to confirm [that the document is accurate]," Une said.

The measure does not cover reptiles. Though they do not carry as many kinds of infectious agents as rodents, many reptiles do carry salmonella.

According to research conducted by a team led by Hideki Hayashidani, assistant professor at the Tokyo University of Agriculture and Technology, which conducts research on infectious diseases in cooperation with Une, 40 percent of turtles and 60.6 percent of lizards tested were found to be carrying salmonella shortly after they were imported. The research team also found 72.2 percent of turtles and 66.1 percent of lizards sold at pet shops had the bacteria.

Hayashidani said the higher number of these animals being found infected with salmonella at pet shops was because many of them become infected during the distribution process.

Specialists warn that children are at the highest risk of contracting these germs because they tend to play with these animals for a long time and are not as resistant to germs as adults.

When a 6-year-old girl and a 1-year-old girl in Chiba Prefecture were infected last year with a serious case of salmonellosis caused by a pet red-eared slider, the Health, Labor and Welfare Ministry issued a warning. Earlier, in the same prefecture, a baby contracted salmonella from an iguana.