Malaria is making a comeback in Venezuela. For the first time in 50 years, the disease, which is disseminated by mosquitoes, is spreading from jungle communities to bustling urban centres. Its revival, experts say, could take at least two years to reverse.

The occasional case in remote mining areas aside, Venezuela declared itself malaria-free in the 1960s. This followed a decade-long effort that included widespread spraying of the DDT chemical compound, educational campaigns and a government-led initiative to improve sewage systems and housing.

Many healthcare officials in this polarised, oil-rich South American country believe the biggest obstacle to eliminating the disease could be a political one. "Unless you have a concerted effort between the government and public health sectors the problem just grows exponentially," said Dr Gustavo Villasmil, health minister in the opposition-led state of Miranda.

In Quilombo, a community of tin-roofed shacks 45km from the Venezuelan capital, Caracas, Jesus Javier Parra has yet to fully recover. His was the second confirmed case of malaria in the area. The fever has subsided, but his face remains gaunt and his body diminished. "I still can't get back to work," he says.

It can take eight to 10 days for symptoms to appear. In the case of Parra, a construction worker in his late 20s, the disease had been undiagnosed for nearly a month because medics did not test for an illness they had never seen occur so close to an urban centre. The delay in appropriate treatment has left Parra seriously anaemic.

"We tested for dengue and tuberculosis, but it never occurred to us it could be the return of a disease that has been absent throughout our professional lives," Villasmil says.

Within weeks, almost a dozen of Parra's neighbours sought help for symptoms of malaria, which can damage the liver and lead to death if untreated. Of the 32 recently reported cases in the state, half come from Quilombo, which – like most informal settlements – lacks basic sanitation. Doctors suspect the green, swampy waters surrounding the community of squatters has become the mosquitoes' breeding ground.

Since the first case of urban malaria was reported in December, the ministry says there have been 22,831 cases nationwide, with 22,000 since January. Although the proportion of infected people is almost 15% lower than during the same period last year, cases have sprung up in three states for the first time in nearly six decades. Until recently, the disease was limited to Bolívar and Amazonas in Brazil, the Amazonian states where illegal mining activity is rampant and where malaria had not been eradicated.

The strain of the disease in Miranda, although not deadly, has caused alarm because it is not clear how it was reintroduced. According to Dr Oscar Noya, of the Centre for Studies in Malaria, an increase in illegal mining activity has contributed to the spread of malaria. "Miners are continually returning to their home towns. An imported case quickly leads to autochthonous cases that, in turn, continue to multiply if the vector [mosquito] finds the right environmental conditions," he said.

In the five months since the first urban case was reported, Villasmil has drained the still waters where the parasite was thriving. His team has fumigated the area, paved roads, distributed treated mosquito nets and eradicated the insect's traditional breeding grounds, such as slow-moving or still water in anything from contaminated creeks to abandoned tyres.

His efforts have paid off. No new cases have been reported in more than two months. But with the rainy season just weeks away, Villasmil fears his work could quickly be undone. The mudslides that accompany tropical rainstorms often leave thousands homeless and forced to seek shelter in informal settlements. Overcrowded and squalid conditions are the ideal habitat of the mosquito.

The biggest hurdle facing the eradication effort, and one the doctor has little faith he can overcome, is the lack of political will to solve the greater health crisis brewing in Venezuela. "There is an express order from the ministry of health to hold no meetings with health teams that might work in opposition-led states."

The division between rival health departments runs so deep that even the official tally of malaria cases differs considerably. According to the health ministry, which was unavailable for comment, there have been only 17 cases of the disease in Miranda.

Malaria is not the only disease to re-emerge in Venezuela in recent years: dengue fever, leishmaniasis and tuberculosis are also reappearing. "These illnesses are what we call in the field the 'illnesses of shame', because it is unjustifiable that in a country that has a trillion dollars from oil revenues in the last decade we are seeing them resurface," Villasmil says.

"Blaming the mosquito is short-sighted. Malaria has returned because the state failed to provide decent housing to the poorest, because it ceased to think of health planning in the long term, and because political differences got in the way."