Seroprevalence and Associated Risk Factors of Brucellosis among Indigenous Cattle in the Adamawa and North Regions of Cameroon.

A cross-sectional seroprevalence study was conducted on cattle in the North and Adamawa Regions of Cameroon to investigate the status of bovine brucellosis and identify potential risk factors. The diagnosis was carried out using the Rose Bengal Plate test (RBPT) and indirect ELISA (i-ELISA), while questionnaires were used to evaluate risk factors for bovine brucellosis in cattle. The Bayesian approach was used to evaluate the diagnostic tests' sensitivity and specificity. The overall individual level (n = 1031) and herd level (n = 82) seroprevalence were 5.4% (0.4-10.5) and 25.6% (16.2-35.0), respectively. Bayesian analysis revealed sensitivity of 58.3% (26.4-92.7) and 89.6% (80.4-99.4) and specificity of 92.1% (88.7-95.2) and 95.7% (91.1-99.7) for RBPT and i-ELISA, respectively. Management related factors such as region, locality, herd size, and knowledge of brucellosis and animal related factors such as sex and age were significantly associated with seropositivity of brucellosis. Zoonotic brucellosis is a neglected disease in Cameroon. The study highlights the need for control measures and the need to raise public awareness of the zoonotic occurrence and transmission of bovine brucellosis in the country. An integrated disease control strategy mimicking the one health approach involving medical personnel, veterinarians, related stakeholders, and affected communities cannot be overemphasized.

Interpretation Criteria for Comparative Intradermal Tuberculin Test for Diagnosis of Bovine Tuberculosis in Cattle in Maroua Area of Cameroon.

Intradermal tuberculin test (TST) is the choice method for diagnosis of bovine tuberculosis (Tb) in live animals. This work was done to assess the performance of single intradermal comparative cervical tuberculin (SICCT) test in randomly selected cattle in Maroua, Cameroon, against detection of Tb lesions and detection of Tb lesions plus acid fast bacilli in lesions. While 22.28% of slaughtered cattle presented Tb lesions at meat inspection, detection rates of anti-bovine-Tb antibody, Tb lesions, and Tb lesions plus acid fast bacilli were 68.57%, 32.95%, and 22.35%, respectively. SICCT-bovine-Tb positive cattle were 35.29%, 29.41%, 25.88%, 24.7%, and 21.18% at ≥2 mm, ≥2.5 mm, ≥3 mm, ≥3.5 mm, and ≥4 mm cut-offs, respectively. Higher sensitivity and predictive values were obtained at severe interpretations. The best performance was at ≥3 mm and ≥3.5 mm cut-offs. Against detection of Tb lesions, ≥3 mm and ≥3.5 mm showed sensitivity of 67.8% and specificity of 94.7% and 96.5%, respectively. For detection of Tb lesions accompanied with acid fast bacilli in lesions, ≥3 mm and ≥3.5 mm showed sensitivity of 89.4% and specificity of 92.4% and 93.9%, respectively. These findings revealed that interpretations of SICCT-bovine-Tb should be at ≥3 mm and/or ≥3.5 mm cut-offs. Severe interpretation of TST is essential for optimal diagnosis of bovine Tb in cattle in Maroua, Cameroon.

Isolation of a 14 kDa antigen from Taenia solium cyst fluid by HPLC and its evaluation in enzyme linked immunosorbent assay for diagnosis of porcine cysticercosis.

A fraction with a major band of 14kDa was obtained from crude cyst fluid of Taenia solium cysticerci by 2-step chromatography. A first fraction isolated by gel filtration (Sephacryl S-300 high resolution) was purified using an anion exchange column (Mono Q HR 5/5) on high performance liquid chromatography. Evaluation of the analytic sensitivity of this fraction (F3) was carried out in an antibody enzyme linked immunosorbent assay (Ab-ELISA-F3) using serum samples from pigs experimentally infected with different doses of T. solium eggs. The cross-reactivity of F3 was evaluated with serum samples from pigs that were naturally or experimentally infected with Taenia hydatigena, Taenia saginata asiatica, Fasciola hepatica, Trichinella spiralis, Metastrongylus apri, Trypanosoma congolense and Sarcoptes scabiei, and with serum samples of rabbits hyper-immunised with metacestode cyst fluid of T. hydatigena and T. solium. Antibody titres of lightly or heavily infected pigs differed in their kinetics. However, the increase in F3-specific antibodies could not be related to the infection level. Analysis of the specificity of the F3 showed that serum samples of pigs infected with other parasites did not recognise this antigen. Cross-reaction with T. hydatigena occurred in ELISA using cyst fluid as antigen, but the F3 antigen fraction was not recognized by rabbit hyper-immune serum samples to T. hydatigena. Evaluation of the diagnostic sensitivity and specificity of the Ab-ELISA-F3 was done by a non-parametric receiver operating characteristic (ROC) analysis using 66 serum samples from Zambian village pigs. The total number of cysticerci of these pigs was determined by dissection (28 pigs harboured T. solium cysticerci and 38 were negative at dissection). In addition, 58 serum samples from Cameroonian pigs (28 pigs from cysticercosis-free farms and 30 pigs with cysticerci at tongue inspection) were used in a separate ROC analysis. The results from the ROC analysis yielded a low diagnostic value (area under ROC curve=0.48) with the sera from the Zambian pigs while a relatively high diagnostic value was obtained with the sera from Cameroonian pigs (area under ROC curve=0.78). The main factor contributing to a low diagnostic value based on the Zambian serum samples seemed to be the false-positive reactions that were likely caused by the occurrence of transient antibodies in the non-infected animals.

Porcine cysticercosis in village pigs of North-West Cameroon.

A study was carried out in two villages and one marketplace of the Batibo sub-division in North-West Cameroon to determine the prevalence of porcine cysticercosis. The results showed that 4.44% of 383 pigs were positive at tongue examination whereas ELISA detected circulating antigens in 27.7% of 271 pig sera. A questionnaire survey in 140 pig-raising households indicated that 59.3% of them lacked latrines while in 75.7% of the households members defecated directly into pigpens. The seroprevalence of porcine cysticercosis was significantly higher in households without latrines than in those with latrines. Similarly, significantly more seropositive pigs were present in households that defecated in the pig pens (35.5%) than in those that did not (14.4%). Although 91.4% of pig raising households did know of pig cysticercosis, only 28.6% were aware of the link with human taeniasis and only 10.7% were aware of human cysticercosis.

Comparison of technetium-99m-MDP, technetium-99m-WBC and technetium-99m-HIG in musculoskeletal inflammation.

UNLABELLED: This study compared three radionuclide techniques in distinguishing musculoskeletal infection from noninfectious inflammation. METHODS: Thirty-five orthopedic patients with suspected musculoskeletal infection were examined using three radionuclide techniques in sequence: triphasic bone scintigraphy, 99mTc radioleukocytes (99mTc-WBC) scintigraphy and 99mTc human immunoglobulin (99mTc-Hig) scintigraphy. Two "early" and "late" acquisitions were performed, at 4-6 hr and 20-24 hr postinjection, respectively. Patients who were diagnosed as suffering from noninflammatory lesions became the controls. We calcu"late"d for all studies one index of inflammation (Infl) as the ratio between counts in the uptake area and counts in an equal area of normal tissue. RESULTS: The "early" radiolabeled leukocytes and "late" Hig scintigraphy allowed the greatest ability to distinguish between infections and noninfectious inflammations (p < 0.011 and p < 0.016) with a sensitivity of 96.6% and 96.5% and specificity of 71% and 100%, respectively. Hig and radioleukocytes allowed distinguishing infections from noninflammatory diseases at both examinations. CONCLUSION: The "early" radioleukocyte scintigraphy allowed us to separate infections from noninfectious inflammations. In contrast, the same result can be obtained only with the "late" scan in the Hig study, but Hig mapped the spread of the inflammation into soft tissues better. Hig might be an alternative to radioleukocytes because of its simple preparation, similar accuracy and safety.

111Indium-pentetreotide pituitary scintigraphy and hormonal responses to octreotide in acromegalic patients.

GH secreting pituitary adenomas are frequently visualized by scintigraphy with the somatostatin analogue 111Indium-pentetreotide. We studied 111Indium-pentetreotide scintigraphy and hormonal responses to octreotide in 12 acromegalic patients. Nine patients with active acromegaly were studied before pituitary adenomectomy; 6 of these and 3 other patients were studied after operation. GH was measured after a single s.c. dose of 100 micrograms of octreotide (acute test). The patients were preoperatively treated with 100 micrograms s.c. tid octreotide for 3 months as were patients who had been unsuccessfully operated; GH and IGF-I were measured at the end of this period (chronic treatment). A decrease of the hormones higher than 50% of basal values was considered a positive response in both acute test and chronic treatment. Eight/nine unoperated patients had a pituitary adenoma visualized by scintigraphy and a positive response to both the acute test and chronic treatment; one patient had no evidence of tumor at scintigraphy and he did not respond to octreotide. Scintigraphy was negative in all of the three patients cured by surgery. Six patients still had active disease after adenomectomy: scintigraphy was positive only in one case, although GH responded to octreotide treatment in all patients. Conclusions. 111In-pentetreotide scintigraphy frequently visualizes pituitary adenomas and predicts GH responses to octreotide in unoperated acromegalic patients. In unsuccessfully operated patients scintigraphy is infrequently positive and does not predict which patients will respond to octreotide. These data and the cost of 111In-pentetreotide scintigraphy do not warrant its extensive clinical use in acromegaly.

Total clearance and extracellular volume with 125I-iothalamate in peritoneal dialysis.

To assess treatment adequacy by calculating total clearance (CL) in patients on peritoneal dialysis (PD), fluids must be collected over 24 hours, a laborious procedure and prone to inaccuracy. CL calculation from the plasma disappearance curve of an injected tracer has none of the above inconveniences. We therefore compared creatinine clearance CR-CL with CL calculated from the plasma disappearance curve of 125I-iothalamate (IO) injected in a single intravenous bolus. Twelve patients aged 63 (44-80) years and on PD for four (1-44) months were studied in hospital. Nine plasma samples were taken for IO-CL after a bolus of 21 kBq/kg of tracer. The least-squares biexponential fitting according to Gauss-Newton-Raphson was then carried out: [Aexp(-at) + Bexp(-bt)], and clearance was calculated by the formula, IO-CL = dose/AUC, where AUC = A/a + B/b. Both CLs were normalized for 1.73 m2 of body surface. Agreement (r = 0.746, p = 0.005) for the CR-CL (6.8 +/- 1.9 mL/min) and IO-CL (7.6 +/- 1.9 mL/min) was good, with a difference of 0.9 +/- 1.4 mL/min (t = 2.182, p = 0.052). Extracellular volume (ECV), calculated from the IO plasma disappearance curve with the formula, ECV = dose/ bAUC, and including the endoperitoneal fluid, was 19.8 +/- 2.9 L (29.5 +/- 6.2% body weight).

Biodistribution of Tc-99m methoxy-isobutyl-isonitrile (MIBI) in humans.

Hexakis (methoxyisobutilisonitrile) technetium(I), 99mTc-MIBI, has been proposed for myocardial perfusion studies. We have evaluated the biodistribution of this new agent in normal volunteers at rest and after stress. The biodistribution of 99mTc-MIBI is characterized by rapid blood clearance and a consequently early myocardial uptake. The initial intense hepatic activity is cleared into the gallbladder at 1 h after injection, and the best target to non target ratio is observed at 60-90 min after injection. Absorbed radiation dose calculations show that the thyroid is the critical target organ (230 mRad/mCi at rest), presumably because of 99mTc-pertechnetate generated in vivo. Our results indicate that 99mTc-MIBI is a promising tracer for myocardial perfusion imaging.