Jacob Diederik Frederik Boomker

Validation of the FAMACHA© eye colour chart using sensitivity/specificity analysis on two South African sheep farms

A validation study of the FAMACHA(©) system for clinical evaluation of anaemia due to Haemonchus contortus was conducted on two commercial sheep farms in the summer rainfall region of South Africa. In this region, the Haemonchus season lasts from October to April. On Farm 1 the system was tested over a period of five successive years in consecutive sets of young stud Merino replacement rams and ewes examined at intervals of 3-5 weeks over each Haemonchus season, under routine farming conditions. When FAMACHA(©) scores of 3, 4, and 5 and haematocrit values of ≤ 22%, ≤ 19%, and ≤ 15% were separately considered to be anaemic, sensitivity on Farm 1 ranged from a maximum of 83% for a haematocrit cut-off of ≤ 15%, to 40% for a haematocrit cut-off of ≤ 22%. Sensitivity increased to 93% when FAMACHA(©) scores of 2, 3, 4, and 5 were considered anaemic at a cut-off value of ≤ 19%, but the positive predictive value decreased to 0.43, indicating that many non-anaemic animals would be treated. The analysis indicated a high level of classification bias on Farm 1, with the animals consistently being classified one FAMACHA(©) category lower (i.e. less anaemic) than reality. On Farm 2 the test was conducted over two successive years in yearling rams evaluated at weekly to fortnightly intervals during each worm season. Every ram judged to be in FAMACHA(©) category 4 or 5 was bled for haematocrit determination, and it was only dewormed with effective anthelmintics if the haematocrit was 15% or lower. When FAMACHA(©) scores of 3, 4, and 5 and haematocrit values of ≤ 22% and ≤ 19% were separately considered to be anaemic on Farm 2, sensitivity ranged from 64% for a haematocrit cut-off of ≤ 22%, to 80% for a cut-off of ≤ 19%. For identical haematocrit cut-off values and proportions of the sampled flock considered to be diseased as for Farm 1, sensitivity was always higher for Farm 2. On the other hand, further analysis of the data indicated that the magnitude of the error on Farm 1 was very consistent on average over the entire trial period. The results of this study indicate that (i) persons introduced to the system should not only be trained, but also be evaluated for accuracy of application; (ii) the sensitivity of the FAMACHA(©) diagnostic system should ideally be evaluated at shorter intervals to avoid production losses due to failure to detect anaemic animals which may be at risk of death; (iii) that calibration of the FAMACHA(©) scoring is essential per individual evaluator, and (iv) that animals should be examined at weekly intervals during periods of the highest worm challenge.

Age- and sex-based variation in helminth infection of helmeted guineafowl (Numida meleagris) with comments on Swainson's spurfowl (Pternistis swainsonii) and Orange River francolin (Scleroptila levaillantoides)

Abstract Gastrointestinal tracts from 48 helmeted guineafowl (Numida meleagris), five Swainsons spurfowl (Pternistis swainsonii) and a single Orange River francolin (Scleroptila levaillantoides) were examined for helminth parasites. Twelve species of helminths were found in helmeted guineafowl, comprising six nematodes, five cestodes and a single acanthocephalan. Six species of nematodes were recovered from Swainsons spurfowl and a single nematode was recovered from the Orange River francolin. First-year guineafowl had more than twice the intensity of infection than did adult guineafowl, particularly regarding the acanthocephalan Mediorhynchus gallinarum, the caecal nematodes Subulura dentigera and S. suctoria, and the cestodes Octopetalum numida, Hymenolepis cantaniana and Numidella numida. Female guineafowl had significantly higher intensities of infection than males, especially concerning M. gallinarum, S. dentigera and N. numida and the nematode Gongylonema congolense. The recovery of the cestode Retinometra sp. from helmeted guineafowl constitutes a new host-parasite record.

Tactical treatment with copper oxide wire particles and symptomatic levamisole treatment using the FAMACHA© system in indigenous goats in South Africa

Haemonchosis is considered to be the most economically important gastrointestinal disease of small ruminants in the tropics and subtropics. However, chemical anthelmintics, which were the mainstay of control, have been compromised by a high prevalence of resistance worldwide. Copper oxide wire particles (COWP) have been shown to have anthelmintic effects, but few studies have examined their use under field conditions. The use of COWP was therefore evaluated as a tactical anthelmintic treatment in indigenous goats raised under communal farming conditions in Bergville, KwaZulu-Natal Province, South Africa. At the beginning of the summer rainfall season (October 2007), the faecal egg counts of 172 female goats belonging to 15 farmers were determined and this sampling continued every four weeks until the second week of January 2008. The goats within each of the 15 herds were ranked according to their faecal egg counts for this week. The goats were sequentially paired off within each ranking starting with those goats with the highest counts. One goat from each pair was randomly allocated to a treated or control group. Two weeks later, a 4 g COWP bolus was randomly administered to each goat in the treated group. Faecal egg counts were carried out on the goats two weeks following treatment, and the sampling of the goats then proceeded every four weeks until October 2008. Except for the six-week period prior to the administration of the COWP, the goats were examined according to the FAMACHA© system and symptomatically treated with 12 mg/kg levamisole when anaemic. The percentage reduction in faecal egg count due to the COWP treatment was 89.0%. Mean pre- and post-treatment faecal egg counts for the COWP-treated group (n = 73) were 2347 eggs per gram of faeces (epg) and 264 epg, respectively. The corresponding values for the untreated controls (n = 66) were 2652 epg and 2709 epg. The prevalence of Haemonchus spp. larvae in pre- and post-treatment faecal cultures was 72% and 46%, respectively. Symptomatic anthelmintic treatments in combination with mid-summer tactical treatments with COWP appear to be useful strategies for the control of Haemonchus contortus in indigenous goats in this farming system and this approach could have application in other similar agro-ecological zones.

Description of Madathamugadia hiepei n. sp. (nematoda: Splendidofilariinae), a parasite of a South African gecko, and its development in laboratory bred Phlebotomus dubosqi (Diptera: Psychodidae).

Madathamugadia hiepein. sp., Splendidofilariinae, a parasite of a South African gecko Pachydactylus turneri is described together with its development obtained experimentally in Phlebotomus duboscqi (Diptera: Psychodidae: Phlebotominae). This new species differs from the two small, more highly evolved groups with a short tail and atrophied postcloacal papillae, the first group consisting of two Madagascan species, M. zonosauri and M. hopluri, parasites of the Gerrhosauridae and Iguanidae, and the second containing three species from the Ethiopian Region, M. huambensis, M. versterae and M. bissani, parasites of the Scincidae. It also differs from M. ineichi, the most primitive species of the genus (cuticularised buccal capsule, no atrophy of head papillae and largest number of precloacal papillae), a parasite of the Cordylidae in South Africa. M. hiepei is close to the two species parasitic in the Gekkonidae of the Mediterranean subregion, M. ivaschkini and M. wanjii, all three of which have a post-oesophageal vulva. However, the new species can be distinguished from the Mediterranean parasites by (a) the shorter oesophagus, (b) the number and position of the cloacal papillae and (c) the microfilaria. The three filariae of this group and M. ineichi, the only ones of which aspects of the life-cycles are known, experimentally develop in phlebotomine sand flies.

A stochastic model accommodating the FAMACHA© system for estimating worm burdens and associated risk factors in sheep naturally infected with Haemonchus contortus

A previously developed multiple regression algorithm was used as the basis of a stochastic model to simulate worm burdens in sheep naturally infected with Haemonchus contortus over five consecutive Haemonchus seasons (November to January/February) on a farm in the summer rainfall region in South Africa, although only one season is discussed. The algorithm associates haemoglobin levels with worm counts in individual animals. Variables were represented by distributions based on FAMACHA(©) scores and body weights of sheep, and Monte Carlo sampling was used to simulate worm burdens. Under conditions of high disease risk, defined as the sampling event during the worm season with the lowest relative mean haemoglobin level for a class of sheep, the model provided a distribution function for mean class H. contortus burdens and the probability of these occurring. A mean H. contortus burden for ewes (n=130 per sample) of approximately 1000 (range 51-28,768) and 2933 (range 78-44,175) for rams (n=120 per sample) was predicted under these conditions. At the beginning of the worm season when the risk of disease was lowest (i.e. when both classes had their highest estimated mean haemoglobin levels), a mean worm burden of 525 (range 39-4910) for ewes and 651 (range 37-17,260) for rams was predicted. Model indications were that despite being selectively drenched according to FAMACHA(©) evaluation, 72% of the ewes would maintain their mean worm burden below an arbitrarily selected threshold of 1000 even when risk of disease was at its highest. In contrast, far fewer rams (27%) remained below this threshold, especially towards the end of the worm season. The model was most sensitive to changes in haemoglobin value, and thus by extrapolation, the haematocrit, which is used as the gold standard for validating the FAMACHA(©) system. The mean class haemoglobin level at which there was a 50% probability of worm burdens being ≤ 1000 worms was 7.05 g/dl in ewes and 7.92 g/dl in rams.

HELMINTHS IN SYMPATRIC POPULATIONS OF MOUNTAIN REEDBUCK (REDUNCA FULVORUFULA) AND GRAY RHEBOK (PELEA CAPREOLUS) IN SOUTH AFRICA

Helminths of mountain reedbuck (Redunca fulvorufula fulvorufula) and gray rhebok (Pelea capreolus) were investigated in South Africa between June 1999 and February 2002. Forty-one mountain reedbuck were culled at Sterkfontein Dam Nature Reserve over 8 different periods, and 25 mountain reedbuck were culled at Tussen die Riviere Nature Reserve over 3 different periods. A total of 17 kinds of helminths were found at the 2 sites, including 15 nematodes, 1 trematode, and 1 cestode. At Sterkfontein, the most prevalent and abundant species were Cooperia yoshidai, Longistrongylus schrenki, and Haemonchus contortus, with the latter 2 being more abundant during November/December than at other times of the year, probably because infective larvae increased on pasture at that time. No statistical differences were found in parasite loads between male and female mountain reedbuck. No correlation was found between fecal egg counts and adult worm counts or between parasite counts and body condition. At Tussen die Riviere, helminths in mountain reedbuck were less prevalent and abundant than at Sterkfontein. The most important species were Nematodirus spathiger, Trichostrongylus falculatus, and Cooperia rotundispiculum. Four gray rhebok died of natural causes at Sterkfontein, from which 5 kinds of helminths were recovered, including C. yoshidai and Paracooperioides peleae.

A new filarial nematode (Onchocercidae) from warthogs ( Phacochoerus aethiopicus ) of the Kruger National Park

Fifty-five warthogs [Phacochoerus aethiopicus (Suidae: Artiodactyla)] from the Kruger National Park, Republic of South Africa, were examined for parasites. Adult filarial nematodes were found in lymphatic vessels adjacent to peripheral and visceral lymph nodes, and microfilariae were found in lymph nodes and circulating blood. Both the adult parasite and the microfilaria are described. Specific identification is pending confirmation and recovery of intact adult specimens and microfilariae identical to those described herein.

Proctocaecum gairhei n. sp. (Digenea: Cryptogonimidae: Acanthostominae) from Gavialis gangeticus (Gmelin) in Nepal and a revised cladogram of Proctocaecum Baugh, 1957.

Proctocaecum gairhei n. sp. is described from the gharial Gavialis gangeticus (Gmelin) in Nepal. The new taxon can be distinguished from all other species of Proctocaecum Baugh, 1957 by the combination of the following morphological characters: a single row of 23 cephalic spines, lateral anal pores opening at uneven levels, a forebody accounting for 16% of the total body length (TBL), an oral to ventral sucker width ratio of 1:0.7, an oral sucker to pharynx width ratio of 1:0.6 and uterine loops that occupy 59–67% of the TBL. While sharing some morphological characteristics with Acanthostomum slusarskii Kalyankar, 1977 from Crocodylus palustris (Lesson) in India, P. gairhei n. sp. is distinguished from the latter by possessing the solid muscular gonotyl diagnostic for Proctocaecum, by the number of cephalic spines, position of the anal pores and egg size. The existing cladogram for Proctocaecum was expanded using the character information of P. gairhei n. sp. The host range of Proctocaecum is now known to include all three families of the order Crocodylia.

NODULAR ABOMASITIS IN IMPALA (AEPYCEROS MELAMPUS) CAUSED BY THE NEMATODE LONGISTRONGYLUS SABIE

The periodic occurrence of nodular abomasitis associated with the trichostrongylid nematode Longistrongylus sabie was observed in impala lambs of the Kruger National Park, Republic of South Africa. The condition was seen predominantly in animals less than 1 yr of age. Peak incidences occurred in the spring and fall, when more than 50% of the lambs studied had from several to numerous nodules in their abomasal mucosae. The nodular lesions in the lambs were macroscopically larger than, but microscopically similar to, those observed in domestic ruminants with ostertagiosis; however, L. sabie worm burdens were much lower than those in clinical cases of ostertagiosis, and no evidence of diarrhea could be found in any of the lambs studied. The physical condition of lambs with moderate to severe nodular abomasitis did not differ noticeably from that of lambs with mild involvement or those without lesions. Nodular abomasitis caused by this parasite was of minimal significance to impala herds in the Park under the circumstances prevailing at the time of the study.

Ufudia, a replacement name for Pelonia Junker & Boomker, 2002 (Pentastomida: Sebekidae) from South African terrapins.

In order to accommodate a new species of pentastomid parasite, Pelonia africana Junker & Boomker, 2002 (Sebekidae), Junker & Boomker (2002) described the new genus Pelonia. This genus name is, however, preoccupied by Pelonia Grube, 1859 (Acari). Grube (1859) did not designate a type species, but Oudemans (1900: 141) recorded Pelonia as a possible synonym of Cepheus Koch, 1835 and listed P. foliosa as its type species, allegedly designated by Grube. Subías et al. (2012), accepted the synonymy of Pelonia with Cepheus Koch, 1835 (Acari: Compactozetidae). Norton & Ermilov (2014) provided a brief summary of the nomenclatural history of the mite genus Pelonia and proposed P. foliosa as being the nymph of Cepheus cepheiformis (Nicolet, 1855).