“I am the front line,” says Thomas Mudangwe. With his blue Honda 90 he stands, almost alone, between 45,000 people resettled on this former white-owned farm in eastern Zimbabwe, and onslaughts of pernicious African disease.

The tall, bearded man with a slight stutter was transferred in 2003 to the Mutasa district in eastern Zimbabwe by the Health Ministry as an environmental health technician (EHT) — close to the “barefoot doctors” used in Mao Zedong’s China — and he walked into a disaster.

Under President Mugabe’s land reform programme, people had been moved with no provision of basic amenities to the Mutasa district and cholera broke out. He had to deal with the outbreak on foot, walking up to 12 miles (20km) a day from village to village in the mountainous bush. Three people died. He was astonished there weren’t more. “The people who were settled in this area had no education. They were illiterate,” he said. “They didn’t know what cholera was.”

Or the link between between human faeces and water supplies that spreads the disease. “They used to defecate anywhere,” including close to the streams where they collected water. When they were taught how to build Blair toilets (a sanitary bush toilet), the next step was to teach them how to use the toilets, he said. “They didn’t know what they were for,” he said. “They were defecating on the ground behind the toilet.”

He was issued with the Honda in 2003, when Riders for Health launched its Zimbabwe operation, and he was ready for the next cholera epidemic. “I could react so fast. I could collect samples, take them to the Government lab in Mutare [the city about 25 miles away], get the results and if they were positive, immediately carry out control measures, and then follow up with surveillance.

“No one died, but if I didn’t have the bike, there could have been a lot of deaths. There hasn’t been another epidemic since then. Now you can move around anywhere in the district and people can tell you what the symptoms are.”

The bike takes Mr Mudangwe all over the area with his trailer loaded with chloroquine and insecticide-impregnated mosquito nets, or cement for building a Blair toilet. With its sidecar-ambulance, he can take mothers in childbirth to the nearest hospital.

He started the area’s first Aids awareness programme in July, persuading people to go for testing at the mission hospital about 15 miles away and distributing condoms out of the back of his trailer. “People are going for condoms now, after only four months. They still fear to go for testing, and they are resistant to change their behaviour. But it will come.

“I am accessible to every village in my area. If ever I am called, I can attend within minutes. Before, people didn’t know I was their EHT. Now every grade one [first year of primary school] kid knows me. They wave at me and call my name.”

The key to Mr Mudangwe’s mobility is a small moustachioed man with the un-Zimbabwean habit of strapping on the seatbelt in the Nissan Champ pick-up truck that he keeps spotless. Alec Makuyana, Riders’ provincial technician, has kept the blue Honda without a breakdown for four years, as well as scores of others in his region.

He arrived at Premier Estates with a few litres of new oil and a range of spare parts that he knew from his minutely detailed records of Mr Mudangwe’s machine, were due as replacements.

“The trouble now is fuel,” Mr Mudangwe said. As Zimbabwe’s world-record inflation sent fuel prices soaring and the black market became the only relatively reliable source, the Health Ministry has struggled to meet the cost of Riders’ petrol.

“I haven’t used my bike for the whole month. I am footing again. If there is an emergency, I will have to try to do the controls and surveillance on foot.”

— CDC Capital Partners will match all donations made to Riders for Health through The Times Appeal