Here’s one story that critics of science and scientists who study global warming will try to avoid mentioning: Malaria’s spread in Tanzania appears to be due to deforestation plus a warming climate that altered historic rainfall patterns.
It’s anecdotal evidence, partly. The case reinforces the point Al Gore made in An Inconvenient Truth, that climate change can smooth the path for the spread of diseases like malaria.
Malaria Threatens Nation’s Highlands
Felix Mwakyembe, 6 March 2011
Mbeya — Tanzania’s southern highlanders have long worried about pneumonia and other respiratory illnesses brought on by the cool, wet weather. But as climate change contributes to warmer temperatures in the region, residents are facing a new health threat: malaria.
In Rungwe, a highland district in the south-western Mbeya region bordering Malawi and Zambia, malaria is fast replacing coughs, fever and pneumonia as the most serious local health problem. The change has taken by surprise the region’s residents, who live over 1,000 metres (3,200 feet) above sea level and outside Tanzania’s traditional malarial zones.
Ms Asha Nsasu, 32, of Isebe village, had no idea she had contracted malaria when she was sent to Makandana District Hospital in late December. “I felt weak. I thought it was pneumonia,” Nsasu said. “Then they told me it was malaria.”
In 2009, health centres in Rungwe district reported 100,966 malaria cases, a jump of 25 per cent from 2006, hospital records show.
Malaria is now the biggest public health threat facing Rungwe district, which lies about 940 kilometres (590 miles) southwest of Dar es Salaam, according to the Tukuyu Medical Research Centre, part of the National Institute for Medical Research. One third of outpatients visiting the hospital were diagnosed with the mosquito-borne illness in 2007, according to records from that year, making it the most common disease for outpatients.
Most highland areas in Tanzania are experiencing a growing burden of malaria cases, officials at the Tukuyu Centre said. Climatic changes brought on in part by local environmental degradation are contributing to the growing prevalence of malaria in the district, said Mr Gideon Ndawala, Rungwe district’s malaria coordinator.
“People have cleared the forests, rain has decreased, temperatures have risen,” Mr Ndawala said in an interview. “(When) I first reported on the district in 1983, it was very cold and it rained throughout the year except from mid-September to early November. The weather was not favourable for mosquito breeding,” he said.
Now, however, temperatures are higher and rain more erratic, he said, and mosquito populations – which thrive on warmer temperatures and breed in pools of stagnant water – are on the rise. Worst hit by the surge in malaria are Tukuyu district town, Ikuti, Rungwe Mission and Ilolo, according to district health officials.
Half a century ago, these traditionally cool areas saw no mosquitoes and did not register any malaria cases, but now the weather is warmer, said Mr Ambakisye Mwakatobe, a 76-year-old man from Bulyaga village in Rungwe.
“In the past, we never saw mosquito nets here. I saw a net for the first time at the age of 20, when I joined Butimba Teachers College in 1957,” he said, in an interview at his village home.
Mzee Mwakatobe said cases of malaria began to appear several decades ago but residents did not relate them to warming temperatures, believing the mosquitoes instead were arriving on buses from lower regions.
“It was in the 1970s when we started getting malaria here. I thought it was the buses from Kyela and Usangu that brought mosquitoes,” he admitted. But “the weather also started to change in those years,” he said.
A half-century ago, “it was very cold here and it rained throughout the year. Three things were compulsory: a sweater, pullover or heavy jacket; an umbrella or raincoat; and gumboots,” he added. “There was frost all day long and cars had to put their lights on.
“But today things have changed,” he said. “Look, now we even put on light shirts. There is no need for sweaters, gumboots or umbrellas.”
Scientists agree that the changing weather is feeding into Rungwe’s worsening malaria problem.
“Up until 1960, districts like Rungwe, Mbeya, Mufindi, Njombe, Makete and Iringa in the southern highland regions were malaria free. Today is quite different – malaria prevalence is high,” said Mr Akili Kalinga, a research scientist at Tukuyu Medical Research Centre.
Malaria accounts for 30 per cent of the burden of disease in Tanzania and is a huge drain on productivity, according to a report produced by research scientists for the Sixth Africa Malaria Day in 2006. In response to the rising malaria caseload, the government is taking steps to stem the disease’s expansion.
Measures include public health education in newly vulnerable districts on home cleanliness and water storage, how to eliminate the places of still water where mosquitoes live and breed, and the use of mosquito nets and fumigation, said Dr Sungwa Ndagabwene, Rungwe’s medical officer.
“The government is taking serious measures to fight malaria. We started with a ‘mosquito nets for all’ campaign – saying every person should sleep under bed nets,” Mr Ndagabwene said.
The government also has begun spraying the inside of homes with insecticide, first in the Kagera Region and now throughout the Lake zone, near Lake Victoria, he said. It plans to expand the spraying programme, which has helped cut malaria transmission in Zanzibar, to the rest of the Tanzania’s malaria-affected regions.
Such spraying programmes aim to kill mosquitoes that land on the inside walls of homes. Spraying can protect homes for between four to ten months depending on the insecticide, according to the World Health Organisation (WHO).
WHO has approved 12 insecticides it considers safe for such spraying programmes, including DDT – a controversial endocrine disruptor that has proved one of the most effective ways to control mosquito populations but that has also been linked to environmental damage and health problems including cancer.
Mr Ndagabwene said spraying the chemical only indoors limited its environmental impact. WHO officials have said they believe the benefits of using the pesticide outweigh its risks. The Stockholm Convention bans the use of DDT but exempts countries that choose to use the chemical to control malaria.
Tanzania is one of the world’s worst malaria-affected countries, recording 14 to 18 million clinical cases annually and 60,000 deaths, 80 per cent of them in children under five years old, according to a 2010 malaria reduction plan put together by USAID.
Children under five and pregnant women are most affected by the disease, official health figures show. (AlertNet)
The author is a freelance writer based in Dar es Salaam
- Also see this story, in which Tanzania’s health minister urges a continued focus on malaria, despite the decline in the disease in the country.