The first survey on the incidence of drug resistant tuberculosis in Cambodia has

brought some good news.

Despite the Kingdom's heavy burden of TB infection, the survey found that resistance

to conventional drugs was running at less than 1 percent. The National Center for

TB Control (Cenat) said that was probably the lowest in the region.

"In comparison last year's WHO surveillance report on multi-drug resistant (MDR)

TB in the world recorded that 2.1 per cent of Thailand's reported cases of 51 per

100,000 population were resistant to conventional drugs," said Dr Nario Yamada

of the Tokyo-based Research Institute of Tuberculosis (RIT).

Dr Yamada was in Cambodia to assist Cenat and its main donor, the Japan International

Cooperation Agency (JICA), collate the survey figures and analyze them for inclusion

in the next WHO surveillance report. Dr Yamada said the findings indicated that current

treatment practices in Cambodia were working.

MDR TB is the result of patients not completing the six month course of treatment,

or indiscriminate use of antibiotics for other minor health complaints. Once the

patient's immunity drops, MDR TB can strike, needing stronger medicines. Other factors

include fake medicines or medicines of insufficient strength.

MDR TB is a growing problem internationally and puts tremendous pressures on the

health care resources of developing countries. Cenat director Dr Mao Tan Eang said

that not only was treating drug resistant TB "100 times more difficult and costlier"

than normal TB, patients could also spread drug resistant TB among the healthy population.

"Even if costlier drugs are administered regularly, the cure rate for MDR TB

is considerably lower," said Dr Eang. "This can seriously affect the country's

overall TB cure rate."

He added that Cambodia has already achieved WHO's targeted 85 percent cure rate for

all reported cases of TB.

Dr Ikushi Onozaki, chief JICA advisor to the national TB control project, said that

although the results were encouraging, they presented a serious challenge.

"With one in every six HIV/AIDS patients in Phnom Penh suffering from TB, the

threat [of the spread of drug resistant variant among the HIV positive population

in particular] is becoming much more serious now," he said.

So far TB patients have not developed resistance to conventional drugs, as some rural

populations have not used antibiotics. Also the Directly Observed Treatment with

Short Course (DOTS) program, made sure that patients stuck to their treatment.

The World Bank-sponsored National TB Drug Resistance Survey started with the training

of local TB health workers September 2000. It was conducted at 30 TB centers across

the country.

The survey collected samples from 900 patients and grew them in laboratories to check

their sensitivity to conventional TB drugs.

"Nearly all the samples were found to be sensitive to the drugs we are using

for our TB control program now," said Dr Eang. He added that the survey would

be repeated in 2005. The WHO estimates that TB prevalence here is 241 per 100,000

population, although reported figures show only 130 per 100,000.

"Improving the detection rate is, therefore, important not only for disease

control, but also to guard against increased incidence of MDR TB," Dr Onozaki

said.