Thursday May 19 2016

Scientists in intensive research effort to eliminate swine fever

Ms Amooti in a pig sty at her home in Masaka. She

A farmer in a pig sty at her home in Masaka. File photo  

By Lominda Afedraru

Scientists from Makerere University have embarked on a study to analyze the African Swine Fever (ASF), a disease which infects domestic pigs and those in the wild which is a major challenge to farmers raring the animal.

The study which has been undergoing since 2009 is aimed at understanding how the African Swine Fever Virus (ASFV) is transmitted into these animals which usually result into major outbreaks leading to severe deaths.

The scientists are conducting this research in order to come up with recommendations for vaccine trials and possible medication for the disease which at the moment is lacking yet the outbreak is usually rampant for farming keeping the animals in the entire country.

ASF is caused by a unique virus which infects only domestic and wild pigs and a variety of soft bodied ticks.

 The virus is endemic in most African countries mainly in warthogs and bush pigs.  It circulates between warthogs and the soft bodied ticks which inhabit their channels.


The ticks transmit it through all stages of their life cycle and preserve it. It is also endemic in the domestic pigs of some African countries with Ugandan farmers facing the challenge.

It is spread by direct and indirect contact between pigs and indirect contact usually involves contamination from dead pig tissues and secretions.

During times of acute infection several pigs develop a high fever of 40-42°C but may not show any other noticeable signs for a couple of days. They then gradually lose their appetites and become depressed.

Their nose, ears, tail and lower legs become blue-purple in colour and discrete bleedings appear in the skin particularly on the ears and sides.

The disease causes pregnant sows to abort. Scientists can only afford to carry out laboratory tests of blood sample and advise farmers to keep hygiene because it has neither vaccine nor medicine for cure.

Professor Charles Masembe from Makerere University College of Natural Sciences who is leading the research team explains the different scenarios under which the virus is transmitted saying it can be passed from animal to animal or from tick to animal.

He was giving a presentation in a sensitization meeting to district veterinary officers in Masaka on April 28, 2016.

According to Prof. Masembe from the time someone spots clinical signs of the virus on the animal, it will die after three to four days because it is difficult to develop antibodies to resist the infection.

The reason why the team is carrying the study of the various pig species including those from the wild is to determine the amount of virus distribution and genetic variation and see if it is possible to control the spread once a vaccine is developed.

Once the virus exists in the soft ticks, it will act as its reservoir for a period of three years. It is presumed that the infection in Warthogs and bush pigs is transmitted through sylvatic ticks which feed on the animal. The ticks will eventually transfer it to the domestic pigs.

Bush pigs are active at the night meaning they can invade farmer fields or feed on the grass which domestic pigs will also come and feed on leading to indirect transfer of the virus.

The virus is a threat to farmers in Uganda and the entire Africa because of the increased contact between wild pigs and domestic livestock.

From the year 2010 and 2011, there were twenty five outbreaks in various districts in Uganda with the district of Moyo hit most.

Prof. Masembe and his team carried out a study in the district of Nwoya in Northern Uganda where Murchison National Park is located.

The scientists sampled wild pigs from the game park and ticks from the wild in the soil where the virus was prevalent. For the animals usually the spleen is tested to establish existence of the virus.

The study which is supported by Wellcome Trust in partnership with the Swedish Agricultural University and Swedish National Veterinary Institute will end in the year 2019.

This is because Prof. Masembe and his team would wish to understand this subject matter and transfer the knowledge to students who will come up with a solution to help farmers’ keeping pigs to overcome the challenge of the disease.

Giving the statistics Prof Masembe explained that more than 70% of the emerging zoonotic infectious diseases originated during the last decades are thought to be of wildlife origin.

Wildlife can act as reservoir of several diseases and therefore foster spill-over events in non-infected livestock populations.

Some examples could be tuberculosis infection with buffalo and cattle populations and foot-and-mouth disease maintenance with buffaloes being the major reservoir.

In Uganda, the total number of domestic pig has been increasing steadily since early 2000, reaching a census of 3.7 million in 2014.

At least one farmer reported to have lost one pig as result of ASFV with the outbreak rated 31.8%

The district veterinary officers from the districts of Arua, Gulu, Zombo, Moyo, Tororo, Kamuli, Wakiso, Sembabule, Mukono, Mbale and Luwero among others while sharing their experience expressed concern about the frequent outbreaks of the virus saying it is important to continuously sensitize farmers to observe bio security measures.

Some of the problem is feed related where millers mix maize bran with soil to add on weight of feeds which is sold to farmers unknowingly.

Dr Kirumura Mukasa the district veterinary officer Masaka stated that the recent outbreak in the district was reported in Kabonera sub-county late November 2015. It spread to 5 rural sub-counties and 3 Municipal Divisions by 10th January 2016 with the mortality rates of up to 90% reported in affected farms.

The team collected 64 samples for testing and 59 tested positive. Usually the outbreaks occur during dry season where farmers have a habit of releasing pigs at night in search for pasture.

Farmer experience

My name is Sarah Amooti Bongyererwe, a widow and a farmer rearing pigs in Kirumba Village, Katwe Division in Masaka Municipality.

I have no strength to talk to you my daughter because I am still nursing the loss of my pigs from the devastating disease where I lost 150 pigs in the recent outbreak.

This piggery is a joint project between me and my son Ronald Mwesigwa who purchased 3 cross breed pigs in the year 2013. Each of the two females ones were purchased at Shs500, 000 each and the male one at Shs700, 000.

I embarked on looking after them and the female ones would give birth to 15 piglets at ago and each would give birth three times a year.

My son used to load a Fuso lorry with fattened pigs which he exported to Rwanda and sometimes he would export pork.

Pigs sold in local market here cost Shs250, 000 at six months and Shs50, 000 for the ones that have been bred for one month.

In November last year, I spotted one pig which looked sickly. This was after my neighbor brought a Sow to mate with our Boar. This Sow died after the neighbor took it back to their pig sty but they did not inform me about its death.

On another occasion I found someone had thrown a dead pig on our compound and this now escalated the sickness of my pigs.

All the 150 pigs died gradually with 5 winning ones which have survived but I urge pig farmers who are keeping these animals to be honest to one another. Once you realize you have a sick animal, please learn how to deal with it other than causing pain to others by leaving it to spread the disease.

It never came in my mind that I should approach the district veterinary office for advice because all I know is that since Naads officials were relieved from their duties, it is not possible to get advice from government on such diseases.

So many quake people pretending to be Veterinary doctors came to my place claiming to give treatment in the names of drugs and vaccine yet I later got to know that ASF can neither be treated nor vaccinated. I spent a lot of money thinking they would cure my animals.

But I was happy to see the district veterinary officer with his team coming to our home. This is after butcher men tipped them about the outbreak of the disease which caused many farmers in the district to lose their pigs.

They took 20 samples for testing which were all positive and all the pigs died. My three hybrid cattle which used to produce milk for my orphaned children died at the same time.

I am a widow who gave birth to 9 children seven of whom died leaving me with five children who are orphans. My son now had paved for me the way to acquire school fees for the orphans through our piggery farm but it all turned out to be a misery.

In case I get some money, I will restock and continue with piggery farming because it is a lucrative business to venture into