Local action can minimize Malaria risk

An interview with Philip Kruger, head of the Malaria Control Programme of the Limpopo Department of Health in Tzaneen.

By Dianne Tipping-Woods and Joël Roerig

Hoedspruit, 9 October 2014

Residential estates, schools and individual home owners in Limpopo Lowveld areas – including Hoedspruit – need to be proactive in the prevention of malaria. A number of locally transmitted malaria cases have been observed, as a result of last year’s late rains and a mild winter. The transmission of malaria can be reduced by dealing with stagnant water in sunny places like puddles, hoof prints or tyre tracks and pools in dry river beds. These breeding places of Anopheles mosquitoes can be removed or treated, to reduce further transmission of malaria.

This is the message of Philip Kruger, who heads the Malaria Control Programme of the Limpopo Department of Health in Tzaneen. Limpopo is a known malaria area, with between 1384 (2012/13) and 6065 (2005/06) malaria cases reported annually. “We are currently seeing around 50 cases a week in Limpopo,” says Kruger. “That is slightly higher than previous years in September and October. These cases are spread out over a wide geographical area, stretching from Musina to Hoedspruit.”

Kruger says the Department is fighting an “all-out war against malaria”, with 42 operational teams conducting spraying to contain the disease. “Some of the cases are however widespread, with isolated cases reported from game lodges and farms, which makes it hard to tackle. That is why people need to take some kind of responsibility. It won’t be expensive and will make a big difference in preventing and controlling malaria at a local level.”

“Houses need to be treated with an insecticide on the inside surfaces. Places where mosquitoes breed need to be identified and eliminated and ideally the human hosts of malaria need to be found and treated, as humans are the natural hosts of malaria, with Anopheles mosquitoes only responsible for transmitting malaria from one human to the next.”

“We need to find a way to locally manage the problem in areas like Hoedspruit. Local communities in developed areas like estates and lodges need to take responsibility. It should be possible in a controlled area, like a wildlife estate or school grounds, to reduce the risk of malaria transmission, to almost zero,” says Kruger. He notes that there are various ways of preventing malaria that individuals can do on a local level. “Local spraying and source reduction can eliminate the local transmission of malaria for many years. However, people tend to get complacent resulting in malaria returning after a number of years.”

According to Kruger the following steps can be taken to protect yourself and your family and community against malaria. The more coordinated the efforts, the better, he implores:

  1. Houses in risk areas need to be sprayed on the inside with chemicals with a residual efficacy, for example Deltamethrin or Alpha-Cypermethrin. Pest control companies can assist the community with this. If a larger part of the community is prepared to organize itself, the Department will be prepared to provide training in this regard. Kruger specifically mentioned members of management or maintenance teams of residential estates and game lodges, who can be trained to effectively spray against malaria.
  2. Breeding places of mosquitoes need to be eliminated. There are three options to eliminate breeding spots: removing standing water, using chemicals or using products containing specific bacteria (Bacillus thuringiensis israelensis), as a biological control method. The first and the last options are completely environmentally friendly, with the biological control suitable for pools in river beds and larger pools around streams and wetlands. When using Bacillus thuringiensis israelensis, the mosquito larvae feed on the bacteria, which can be applied to standing water in granule form and prevent the larvae from maturing into adult mosquitoes .
  3. The suspected carriers of malaria should be traced and treated. According to Kruger, through many years of intense malaria control, the disease is not prevalent in local communities in South Africa. It is suggested that the malaria parasites are brought into our communities through migrants from countries with little or no malaria control. Industries or companies that employ (casual) labour from malaria endemic countries can make a huge difference by having these workers tested and when found positive – treated. Employers should help educate and protect their employees by sharing information on how to prevent malaria and seek treatment at the first sign of the disease.
  4. Take precautions. Install gauze in front of open windows and doors and make sure the house is closed from sunset to sunrise. The malaria mosquitoes don’t fly or feed during day time Have your house’s interior walls treated (sprayed), use mosquito mats and insecticide treated mosquito nets. Strict precautions can reduce your risk to “almost zero percent” says Kruger.
  5. When outdoors at night or in areas not screened from mosquitoes, apply mosquito repellents to ALL exposed skin, using products like Peaceful Sleep or Tabbard. Citronella based repellents are not as effective, according to Kruger.
  6. Be overprotective when it comes to babies and small children and request malaria tests when observing malaria symptoms like fever, headache, body pains, vomiting and diarrhea.

Below is the full interview with Philip Kruger, who heads the Malaria Control Programme of the Limpopo Department of Health in Tzaneen.

How does malaria spread?
“Malaria parasites come from people,” says Kruger. “A specific mosquito transports the parasite from the infected person or the asymptomatic carrier to the next,” he says, referring to the female Anopheles mosquito. The parasite goes through a cycle in the mosquito, that takes about 14 days After 14 days the bite from an infected mosquito inserts Plasmodium parasites into the blood of a human. These parasites travel to a person’s liver where they mature and reproduce. “Malaria bearing mosquitoes are only active at night, but it only takes one bite to get malaria. The incubation period – the time from receiving the infected bite till one observes the symptoms – is about two weeks in humans. This all means that if malaria is contracted at a specific place, a person who carried the parasite should have been in the vicinity approximately 4 weeks before the onset of the disease. Malaria is a disease that can be treated successfully. However, if it does not get diagnosed and treated quickly, it results in complicated or severe malaria, leading to death.”

What is the history of malaria around Hoedspruit?
“In Central Africa there are very high levels of malaria and people can get 5 to 10 bites a night. When a child gets born in Central Africa, they get a bit of acquired immunity from their mother. They lose that after 6 months and 20 percent of children die of malaria in the first few years of their life, before they acquire their own immunity.”

“Years ago the same was true for the local indigenous population in the Lowveld. After the 1940s malaria control programs were started, which cleared the area of the disease to a large extent. We believe that South Africans, whether they are of indigenous or European decent, no longer have any immunity against malaria, regardless of where they live or how long they have lived there.”

Kruger is co-author of the paper Malaria incidence in Limpopo Province, South Africa, 1998–2007, which concluded there was a “decreasing trend in the incidence rate”.

What are the recent developments around malaria in Hoedspruit?
“Malaria cycles are dependent on, among other things, weather patterns. During 2012/13, we have observed the lowest incidence for malaria over the past 17 years. An increase has been observed in 2013/14. Since the publication of the paper, the overall decrease did continue. But there is an increased trend of isolated transmission occurring on remote settings like ranches and game farms. It is difficult for us to combat, because the cases are not concentrated around one focal area. It is sporadic and widespread. Yes, it is a problem.”

How does malaria get into the Hoedspruit area?
“We suspect South Africans are not carriers of malaria. Our suspicion is, based on an ongoing study, that malaria parasites come in via migrant workers. These are mostly people coming from malaria endemic countries. There have been efforts to address the local community on malaria and the prevention and control thereof. The department had a malaria session to address the local community in Hoedspruit at the beginning of this year, but the turnout was very poor.”

Do the trucks increase the malaria risk in town?
“There are suggestions that the trucks that drive up and down between Phalaborwa and Mozambique contribute to malaria. The transportation of infected mosquitoes is extensively documented and is called “airport or taxi malaria”, but we do not believe that this is the case around Hoedspruit. The trucks are coming from Maputo, which is not considered a high transmission area. If the truck drivers were carriers, there would be more issues at other places along the route like Bushbuckridge.”

What about the early cases this year?
“This year we have seen quite a lot of malaria early. There is a lot of surface water, because of the late rains in January, February and March. A strong winter normally kills the mosquitoes, but even in winter you can have the odd case. We are currently seeing 50 cases a week in Limpopo, but those are widespread, which makes it harder to tackle.”

What can the province do?
“The Malaria Control Programme in Limpopo preventatively sprays a million houses each year, mostly in rural areas. The department of health has 60 teams and 700 people, actively involved in controlling malaria. They are doing good work and are quite committed. Just in the last few weeks, we have sprayed 180.000 houses. As a public health intervention, spraying of houses in developed parts of our communities is difficult, due to lack of access to these houses. The environment in developed communities normally does not lend itself to malaria mosquito breeding. The control intervention employed by the control program won’t stop transmission completely in the very short term, but it will prevent onwards transmission and outbreaks.”

What about Hoedspruit?
“We need to find a way to locally manage the problem in areas like Hoedspruit. Local communities in developed areas like estates and lodges need to take responsibility. It should be possible in a controlled area, like a wildlife estate or school grounds, to reduce the risk of malaria transmission, to almost zero,” says Kruger. He notes that there are various ways of preventing malaria that individuals can do on a local level. “Local spraying and source reduction can eliminate the local transmission of malaria for many years. However, people tend to get complacent resulting in malaria returning after a number of years.”

What should estates, schools and home owners do?
“You need to get rid of any possible breeding areas, which are sunlit pools of natural water in the veld. Mosquitoes don’t breed in deep fish ponds or big areas of open water and a wetland normally has a lot of other predators like frogs that feed on mosquitoes. But on the edges of wetlands and dams mosquitoes can breed, for example in hoof prints. The water seeps into it, gets hot and the mosquitoes can finish their breeding cycle within 10 days.”

What options are there to eradicate mosquito breeding areas?
“There are three options: removing standing water, using chemicals or using products containing specific bacteria (Bacillus thuringiensis israelensis), as a biological control method. The first and the last options are completely environmentally friendly, with the biological control suitable for pools in river beds and larger pools around streams and wetlands. When using Bacillus thuringiensis israelensis, the mosquito larvae feed on the bacteria, which can be applied to standing water in granule form and prevent the larvae from maturing into adult mosquitoes.”

What is the purpose of in-house spraying?
“The mosquitoes go into your house, feed and then sit on the wall. We treat the ceilings and the inside walls to the point that the substance almost runs off, like spray painting the walls. If mosquitoes sit on the walls they will die and the effect will last for 3 to 4 months.”

Who should do the spraying?
“Ideally our program gets all the houses sprayed,” says Kruger, but he is doubtful that this is feasible in Hoedspruit, because getting permission from home owners is much harder than in the rural areas where their programs usually take place. He says there is a role for local businesses, but individuals or estates can also (learn to) spray themselves.

What can people do to prevent infection?
“The mosquitoes mostly fly and feed between 18h00 and 21h00 and early morning, although they can bite throughout the night. Install gauze in front of open windows and doors and make sure the house is closed from sunset to sunrise. The malaria mosquitoes don’t fly or feed during day time. Have your house’s interior walls treated (sprayed), use mosquito mats and insecticide treated mosquito nets. Strict precautions can reduce your risk to “almost zero percent” says Kruger.

“When outdoors at night or in areas not screened from mosquitoes, apply mosquito repellents to all exposed skin, using products like Peaceful Sleep or Tabbard. Citronella based repellents are not as effective, according to Kruger. Be overprotective when it comes to babies and small children and request malaria tests when observing malaria symptoms like fever, headache, body pains, vomiting and diarrhoea.”

What can the province do about the current cases?
“Our teams respond to every confirmed malaria case and a full investigation gets conducted if we are notified of local cases.”

What can Hoedspruit residents do?
“People need to take some kind of responsibility. It won’t be expensive and will make a big difference. Houses need to be treated on the inside, places where mosquitoes breed need to be removed and ideally the human sources of malaria need to be found. Mosquito breeding control would solve the problem. With spraying and source reduction you can locally get rid of malaria for another ten years, until people get complacent again.”

Kruger is co-author of the paper The feasibility of malaria elimination in South Africa, which concluded eradication is “is a realistic possibility if certain criteria are met”.

Can we get rid of malaria?
“On an island you could eliminate it, but in this area? We were very close for many years to eliminating it. In the sixties there were good programs in Mozambique and Zimbabwe, in the 70s and 80s the border control was very strong. We were on the edge of elimination. But a few other things happened as well, the parasite changed its resistance and so did the mosquito. Now, we’re falling behind a bit.”

How does the spraying work?
“The products you can use are Alpha-cypermethrin, which is locally available at NTK and similar shops, and deltamethrine. You could do it yourself. The cost can be very low. Ideally, what you need is a small sprayer that you can pressurize; it needs to be fitted with an 8001 flat fan nozzle. Most sprayers come with a cone nozzle .”

“You need to remove fish and birds from your home. This is another reason why it is difficult for my big teams to spray westernized houses. The spray will not harm other domestic animals like cats and dogs. You need to wear some basic protective clothing like gloves and a long sleeve shirt that you can wash afterwards. Also cover your face. The insecticide will cause local irritation where is falls on you, but would not cause serious harm. Unfortunately you will also kill little geckos.”

“The only mistakes you can make are either to over or under-apply a little bit. You can redo this every three months. Be careful for fall-out (the mist) on pillows in bedrooms as when you sleep will pick up skin irritation. Best is to cover all furniture in room with sheets, that you can wash afterwards. Alternatively, hire a pest control operator.”

We also spoke to experienced Hoedspruit GP Dr. Mark Blair about self-tests, checking your temperature, taking all possible precautions and important rules for your Christmas visitors. His central message is Take responsibility for malaria prevention and detection.

Note by the editors: The commercial products available to spray houses include K-Othrine WG and Fendona. These products are available from Coopers Environmental Science and the bacterial granules to treat pools can be bought from Avima in Krugersdorp. We have been informed that to spray your own house, you need to mix 2 x 25 g sachets in 10 litres of water. If the sprayer is 5 litres, add Fendona 160ml or K-Othring one sachet 20g. If you only have a cone nozzle, you can also do the work. You spray this mixture on the inside walls, ceiling and even onto curtains. You need to wet the wall to just before run-off point. We cannot guarantee the accuracy of this info and suggest you consult the manufacturers for more info or contact a pest control service provider.

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