Diseases of economic and zoonotic importance in pig farming in Uganda: Control practices, successes, failures and the way forward
“Workshop: In-depth smallholder pig value chainassessment and preliminary identification of best-bet interventions, Kampala, 9-11 April 2013”Diseases of economic and zoonotic importance in pigfarming in Uganda: Control practices, successes, failuresand the way forwardZachary Nsadha
The drives for pig farming; Pig farming and consumption of pork is on theincrease (Waiswa et al 2007, Ampaire and Rothchild2010) There is deliberate effort by Govnt, NGO eg Vedeco tosupport pig farming as an enterprise (MAAIF policy2004, www.naads.or.ug)
MERITS FOR PIG AS AN ENTERPRISE FOR THEPOOR Can multiply very quickly ; capable of 6-10 viablepiglets per furrowing, can have 2 viable furrowing peryear. Can grow to market size in a short time; 5-6 months apig can be ready for market slaughter Can thrive in low-in-put systems; it is omnivorous,complete scavenger to the extent of being coporophagicin the rural setting, most of the pigs are kept bythe small holder at free range system
DISADVANTAGES OF KEEPING PIGS AT FREERANGE PIG Pigs are at high risk of acquiring of diseases. production limiting, such as the helminths Ascaris suis andTrichuris suis (Stewart and Hale, 1988, Nansen andRoepstorff, 1999) the highly pathogenic (fatal) virus causing African swine fever(Bengis et al., 2002), have serious public health consequences,(a) Cysticercosis caused by the zoonotic helminth Taenia solium(Pondja et al., 2010, Sikasunge et al., 2007(b) Trichenellosis (Schuppers et al., 2010),(c) Toxoplasmosis (van der Giessen et al., 2007)
IMPORTANT DISEASES TO PIG FARMING INUGANDA African swine fever: very pathogenic and fatalcausing a lot of mortalities Porcine cysticercosis: A zoonotic disease causingloss of income and devastating disease in thehuman (neurocysticercosis) Intestinal Worms: cause retarded growth andpoor returns from the pig enterprise. Ectoparasites and mange: retarded growth inyoung ones
PORCINE CYSTICERCOSIS INUGANDAPorcine cysticercosis is a confirmed disease entity in Uganda Slaughter slab surveys: in Moyo district;33.5%, 34.1% and44.9% for Moyo town council, Moyo and Metu sub-countiesrespectively (Anyanzo, 1999). Wambizi pig abattior 9.4% (Kisakye and Masaba 2002) 42 % sero-prevalence at Wambizi (unpublished information ) Field surveys: 8.9% (Ag ELISA) in Kamuli and Kaliro (Waiswa et al, 2009) , 9.4%, 7.7%, 8.2%, 6.9%, 0%, 12.9% and 4.1% (lingual )Oyam, Apac, amolator, Kaberamaido, Kayunga, Kamuli andKaliro (Nsadha et al 2010). (AgELISA) 27%, 11%, 14.2% and 15% Arua, Busia, Kibaleand Masaka to be respectively (Nsadha et al, 2011).
RISK FACTORS FOR ACQUISITION OF PORCINECYSTICERCOSIS1. PIG HUSBANDRY PRACTICES Intensive pig keeping is 2% of pigs in schools and religiousinstitutions The mode of keeping pigs depends on the crop season. In the LakeKyoga basin, During planting and growing, there is restrictionduring the day and most pigs are tethered on to pastures. 80% of the pigs are under the intermittence of free range andtethering. During fallowing almost all pigs are at free range all thetime (Nsadha et al 2010) In soroti distrcit 48% of the pigs were under the tethering, 46%were at free range and only 6% were kept intensively (Ziruntunda2011) Tethering of pigs is done to the bushes where open –air defecationis carried out by humans thus pigs can feed on infected materials
2. PRACTICES OF THE REGULATORY AUTHORITIES INLIVESTOCK MARKETS
Pigs diagnosed positive (lingual cysts) are rejected by the inspector sale of such pigs is not allowed in the marketthe affected farmers are advised to take back the pigs to their homes(ochero and awelo livestock markets). The farmers whose pigs were rejected were observed to take awaytheir pigs very quickly before fellow community members can get toknow about the rejection.Clandestine sale/slaughter is the likely fate of such pigs
3. LACK OF PORK INSPECTION DURING CLANDESTINESLAUGHTER. 90% of the pork sold in the villages is not inspected (Nsadha et al 2010).Clandestine slaughters in ungazzted places makes it hard for vet. personnelto follow the slaughters (Dr. Kyokwijuka personal communication).human taeniosis infections are very much likely 4. Lack of enforceable legislations for destruction of infected pigs; Sale ofinfected pigs with the communities is a common occurence.the ‘let me not make loss voice’ rides the day in the communities5. Poor conceptions/perceptions among the communities Only 12 % of the respondent knew that pigs get infected by eating humanfeaces. Only 16 % knew that humans get infected by eating infected pork. Because of ignorance, Communities can not practice preventative measuresto limit transmission of infections to pigs/humans.self evaluation and preventative measures are key to disease prevention incommunities
The “sieve” at wambizi is likely to be very porous6. Poor pork inspection practices at slughter places
7. Improper human feaces disposalIn the rural settings of Uganda, 20% of the householdslack toilet facilities (UBOS Report 2002).Soroti District 54% of the households do not have latrines(Zirintunda 2011).Poor commitment to use latrine is a common occurrence ,38% in Adumi S/C (Arua) of the latrines were not being usedie lacked indicators of latrine useThere is a lot of open-air defecation in the rural communities inUganda
(a) Very unhygienic handling of pigs/pork at slaughter expose to allsorts of contamination(b)Poor cooking is determined by some factors;(i) demand of the day; the higher the demand the lessconcentration to cook properly.(ii)the fuel source available; very poor fuel to give enough heat.(iii)the state of consciousness of the consumers ; most of the porkin the rural areas is eaten at drinking points. The seller may release poorlycooked pork to the drunk customers or those in transit who are in a hurry.under cooking is common in most of the rural pork jointsand those pork roasting areas along the road side ofinternational trade routes-transmission to humans
9. SOURCES OF WATER FOR DOMESTIC AND ANIMAL USE.. In the rural Uganda 44% of the households do not have access tosafe water (UBOS, population and housing census 2002).. In the Lake Kyoga basin, 60% of the households fetch onlydrinking water from boreholes. Most of other water for doemasticuse comes from unsafe sources (Nsadha et al 2010).Drainage of feaces into the water bodies is known and the firstrains after a dry spell are called names indicative of washing awayfeaces into the water holding bodies (Ogwa-cet -Langi, kothmarapena orwok ceth-Japadhola (personal communications fromDrs. Agwai& Okuni J).This is a very dangerous route of infection where man can easily getTaenia egg infections to cause human cysticercosis
CONTROL OF PORCINE CYSTICERCOSIS IN UGANDA1. Lingual inspection; this is the control carried out in livestockmarkets eg Ochero, awelo and Karachi (Amolator andKaberamaido)Success; it helps in identifying infected pigs that a removed fromthe normal trade chain. It also alerts the Veterinary and publichealth personnel about the disease.Failure;i) it is just a simple whistle blower on very shallow approach sincevery many cysticercotic pigs may be lingual negative.ii) The rejected pigs are left with the farmers who have noenforceable obligation to destroy the pigs hence clandestineslaughter/sale to unsuspecting community members is theimmediate option to the rural poor farmers.Clandestine slaughters have been observed to help in transmission ofthe disease (Praet et al 2010, Zoli et al 2003 Cysticercosis workinggroup Peru, 1993)
2. Pork inspection;Success; is a regular activity at only one place in Uganda (Wambizi )pigslaughter house. Less than 0.1 % of the slaughters are diagnosed havecysticercosis at meat inspection per yearFailure; the inspection being carried out is very superficial and can notdetect lightly infected pigsThe control measures being used in uganda help only to stop thetransmission from a very small proportion of infection. There is needto try to prevent transmission from all the known avenues
CONTROL MEASURES USED ELSEWHERE OUTSIDE UGANDA1. Community led total sanitation (CLTS).(Kamal Kar, Institute of development studies University of Sussex BrightonUK.) The communities are made to under go attitude and behavioral changetowards sanitation . Awareness is carried out and the members of the community designs the wayto stop the human fecal disposal It is assumed to stimulate the construction and use of latrines in a cascademode. The community tends to police the activities. It is being promoted by international NGO eg Plan international , UNCEF,WaterAid etc (www.community ledsanitation.org)It has bee tried;Kenema district , Sierra leone. has attained ODF statusTubmanburg, Liberia started and target is ODF by June 2013
2. Public health and pig management” education interventions.Is where there is aggressive education campain in many of thecommunities; markets, schools, workshops etc. Educational materials eg videos, leaflets, posters,booklets and training manuals are given tocommunities. The training materials are made more of pictorial thantext so that they can lend easily to even the illiteratemembers of the communities. The leaflets and booklets are distributed to thehousehold for daily references.
The communites are advised to follow/adhere to the eightcysticercosis fighter principles;(a)build pig pens and never allow pigs out of the pig pen.(b)Dig and use an enclosed latrine with a closing door forall human defecations.(c)Immediately dispose children’s’ feaces in pit larine.(d)Thoroughly wash hands after latrine and before eatinganything.(e)Boil water for domestic use.(f)Never eat or sell infected pork.(g)Consult a livestock extension officer whenever signs ofcysticercosis are seen in pork.(h)Consult medical services if signs of worms or epilepsyhappen in any member of the household.Note: incentives (pig feeds, compensation for thecysticercotic pig) are needed if the rural poorfarmers are to comply with the protocols used in thisapproach) (Ngowi et al 2008)
3.Chemotherapy to pigsOxfenbendazole and albendazole have ability tokill the cysts of Taenia solium with in the body ofthe infected pigs.This can deter infecting the human.It can be used to treat (pre-slaughter) infectedpigs before they can be slaughtered for humanconsumption.(Pondja et al 2012).
4. Combined mass human and porcine chemotherapy.Mass chemotherapy (praziquantel) for intestinal Taeniaworms in the humans Mass chemotherapy for porcine cystocercosis(oxfenbendazole) is a possible control strategy.The mass treatment in the humans is assumed to clearthe humans of the Taenia solium worms which reducesthe environmental contaminations hence less infectivematerials for the pigs.The mass treatment in the pigs is assumed to clear pigsof the larvae of Taenia solium which reduces infectivematerials for the human beings. It also has an economic value in that the porcine meatis cleared of the cysts hence less condemnations of pork(Garcia et al, 2006)
There is a possibility of mass contamination of theenvironment due to the mass expulsion of Taenia from the humansat the same time, if open-air defecation is carried out Inflammatory reactions occur to the cysts in the muscleswhich can make the meat unsightly and unsuitable for humanconsumption for approximately 6 months (Sikassunge et al 2008). Treated pigs remain susceptible and re-infections canoccur and the re-infected pigs can transmit the parasite with inshort time. Coordinating the giving the drugs and slaughter before re-infection can be very problematic and can fail the exercise (Assanaet al 2010).Disadvantages;
5. Vaccination of pigsVaccination was identified as valuable approach for the control ofcysticercosis by preventing transmission of Taenia solium (Lightowlers1999).TSOL18 vaccine has been proven effective in trials in Mexico, Peru,Cameroon and Honduras with 99.3-100% protection againstexperimental challenge infections (Flisser et al 2004, Gonzalez et al 2005Lightowlers 2006). Successful Field trial has been carried in cameroonAssana et al 2010)
Good and effective control program will involve amulti-disciplinary and multilevel approach due to thecomplex epidemiology of Taenia solium. This willdemand full cooperation of medical, public healthworkers, veterinarians and the communities . All needto be working in synergistic approach for propercontrol/reduction in the occurrence of Taenia soliumcysticercosis. Laxity of any of the actors will fail anycontrol program. (Murell and Pawlowski 2005)General conclusion about control of porcine cysticercosis
AFRICAN SWINE FEVERAfrican swine fever (ASF) iscaused by the African swinefever virus of the asfivirus.
Impact of ASFIt is endemic in UgandaMany mortalities in any out break (70-100%A lot of resources wasted in regular surveillanceThe depopulate strategy costs framers the investmentDiscourages breeding strategy
Control of ASF in UgandaHalt to the movement pigs and productsto and from areas of out break.Rapid slaughters of all the contact pigs tothe affected flocks
Proposed control of ASF Improve production systems ; housing, hygiene, avoid uncooked swillImpose well legislated/ enforceable quarantinesControl of pig trade; health ASF pathogen free pigs are allowed for trade.Prevent possible interaction domestic pigs with wild suids.Eradication of ticks in sties before introducing new pigs.Proper basic bio-security (footbaths, restricted visitation to the farm) Sale of bush meat (wild siud) be done in approved safe ASF proof ways.Continued surveillance, eradication of infected by total slaughter of thesick and those in contact pigs. This needs some organ eg the state to putin place compaciatory effort for the farmers to have full compliance andcooperation.Total confinement total closed system where influence of pigs/otheranimals is minimized should be encouraged
Pig holdingareaBare groundfor dailysweepingMost peripheralperimeterMiddle perimeterSurface fortick controlEntry/existDisinfectantFoot bathProposed enclosure for ASF control
Foot and mouth disease in pigs in UgandaThis is not considered as a threat to the pigindustry. The role of pigs in the cycles of FMDobserved in the country is not known(Drs. Kyokwojuka and Asimwe A. MAAIF)
Intestinal worms in pigs in UgandaNematode exist in pigs in Uganda (Nissen et al 2011,Waiswa et al 2007.Impact;Some are zoonotic A. suum, T.suisControl ; de-worming with antihelmenticsAdvice; indigenous Traditional knowledge on wormcontrol be explored (Prof. Ejobi)
Ecto-parasites in pigs in UgandaMange lice, fleas, and jiggers are common in pigs in UgandaImpact; poor growthControl; acaricides and ivermectin is used