HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (12) Citing Articles via Google Scholar Google Scholar Articles by IRMAK, H. Articles by SMITS, H. L. Search for Related Content PubMed PubMed Citation Articles by IRMAK, H. Articles by SMITS, H. L. Related Collections Zoonotic Diseases Brucellosis

USE OF THE BRUCELLA IgM AND IgG FLOW ASSAYS IN THE SERODIAGNOSIS OF HUMAN BRUCELLOSIS IN AN AREA ENDEMIC FOR BRUCELLOSIS

ABSTRACT

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
The clinical utility of two complementary tests for brucellosis, the Brucella IgM and IgG flow assays, was evaluated in a hospital in eastern Turkey. The results show that the flow assays are convenient diagnostic tests for use in endemic areas. A positive result in the flow assays was obtained in 91% and 97% of the admission sera from adult and pediatric patients with brucellosis, respectively, and the sensitivity at admission was 100% for culture-confirmed brucellosis. The assay system performed equally well in diagnosing patients at different stages of illness including patients with acute, subacute, or chronic disease and with relapse. The results of the flow assays correlated well with those of a serum agglutination test at a cut-off 1:160. The agreement was 92%. Application of the flow assays on serum samples collected during a village survey for brucellosis after an outbreak demonstrated their diagnostic potential as field tests.

INTRODUCTION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
Brucellosis is a multi-system disease that may present with a broad spectrum of clinical manifestations and that requires laboratory testing for diagnosis.¹ The isolation of the organism from blood samples or other clinical specimens is the confirmatory test for the disease. However, the sensitivity of this technique depends on the stage of illness as well as on other factors. Furthermore, culture does not provide a rapid result and many laboratories in endemic areas do not have culture facilities. Therefore, the diagnosis often relies on serologic testing. Not all physicians in areas that are endemic for brucellosis have access to laboratory facilities, and in these problematic situations a rapid field test with a high sensitivity and specificity is urgently needed. The Rose Bengal (RB) test is widely used as a rapid and simple screening test but requires confirmation by other tests because false-positive results may occur in endemic areas.^2,3 For this the classic Wright tube agglutination test or the standard serum agglutination test (SAT) may be used.^4–6 These agglutination tests are relatively complicated and time-consuming to perform. The recently developed immunochromatographic lateral flow assays, the Brucella IgM and IgG flow assays, for the detection of Brucella-specific IgM and IgG antibodies, respectively, are much easier and quicker to perform and are well standardized.⁷ The flow assay is simply performed by the addition of a drop of serum followed by some running fluid to the sample well of a plastic assay device. The test result is read after 10–15 minutes by visual inspection for staining of the antigen line in the test zone of the assay device. In a laboratory-based evaluation study, we demonstrated a sensitivity for the flow assays of 96% for admission sera from patients with culture-confirmed brucellosis, and showed that the sensitivity is equally high for patients with acute and with chronic disease.⁷ No significant degree of cross-reactivity when testing samples from patients with illnesses other than brucellosis was observed. The Brucella IgM and IgG flow assays thus would be ideal for use in areas that are endemic for brucellosis and in developing countries.

Brucellosis is still endemic in Turkey and presents a major public health, clinical, and diagnostic problem among the largely rural population, in particular in more remote parts of the country.^8,9 The incidence of human brucellosis in Turkey is estimated to be 0.59 per 100,000 per year, but can be much higher among specific groups. The high incidence of brucellosis in Turkey is due to the widespread infection among domestic animals and the frequent contacts with livestock and the consumption of raw milk and traditionally prepared soft cheeses by the rural population.^10,11 The presents study was undertaken to confirm the clinical utility of the Brucella IgM and IgG flow assays when applied in a clinical setting in an area that is endemic for brucellosis. The study was performed at a university hospital in eastern Turkey and demonstrates that the assay system will be very useful for the confirmation of brucellosis in situations where brucellosis is common.

MATERIALS AND METHODS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
Patients and clinical specimens. Three groups were studied. Adult patients hospitalized with clinical suspicion of brucellosis. Adult patients (n = 172) admitted with clinical suspicion of brucellosis to different departments of the Yüzüncü Yil University Medical School Hospital in Van, Turkey were entered into the study. Sixty-three adult patients were diagnosed with brucellosis based on clinical findings and laboratory testing and treated accordingly. A final diagnosis other than brucellosis was reached for 24 patients and this included 10 patients with (para) typhoid fever. The final diagnosis was debated in the remaining 85 patients because of inconsistent or incomplete clinical and or laboratory findings and these were designated as an unconfirmed diagnosis. Of the 63 confirmed cases of brucellosis, 26 had symptoms and signs for less than two months at the time of first diagnosis and were considered acute, 22 had been ill for 2–12 months (subacute), and 11 had been ill for more than one year (chronic). The four other patients had been previously treated for brucellosis and had a relapse. An admission sample was available from 54 patients with brucellosis, including the four patients with a relapse. Follow-up serum samples (n = 76) collected 1–30 weeks (median = 5 weeks) after the start of treatment were available from 30 of these patients with an admission sample. Admission sera were not collected from nine patients with brucellosis. Single serum samples collected during treatment were available from four of these nine patients and two or more samples were available from five of these patients (n = 16). Single serum samples collected at admission were available from 20 of the 24 non-brucellosis patients. A total of nine follow-up sera collected at different time points during treatment were available from the other four patients. Only admission sera were available from the 85 patients for whom the final diagnosis was debated.

Pediatric patients with brucellosis. There were 33 pediatric patients with brucellosis who had been admitted to the Department of Infectious Diseases at Yüzuüncü Yil University. Only single serum samples collected at the time of diagnosis were available from these patients.

Villagers participating in a survey for brucellosis. Single serum samples were collected from 27 individuals during a village survey for brucellosis in the village of Deg irmenarki in the province of Van. This village is located in a remote area that is difficult to access and is approximately 95 km from the city of Van. The survey was performed in June 2002 following the presentation of three villagers with severe brucellosis to the hospital of Yüzuüncü Yil University and the reporting of a disease outbreak that included stillbirth in livestock kept by the villagers. The survey was organized by the Department of Infectious Diseases.

The ethical committee of Yüzuüncü Yil University reviewed and approved the study and informed consent was obtained from all patients or their guardians.

Laboratory testing. All laboratory testing for brucellosis was performed at the Department for Infectious Diseases. Hemoculture was ordered only for patients hospitalized at the Department for Infectious Diseases.

The RB test and the SAT were performed according to standard procedures. Briefly, for the RB test, undiluted serum samples (30 µL) were mixed with an equal volume of Rose Bengal Slide Screening Test antigen (Biotech Laboratories, Barcelona, Spain) on a white agglutination card. Results were rated negative when agglutination was absent and 1+ to 4+ positive according to the strength of the agglutination. The SAT was performed by preparing two-fold serial dilutions of the serum sample starting at a dilution of 1:20 in the wells of a microtiter plate and the addition of an equal volume of stained Brucella abortus antigen MM101 (Linear Chemicals, Barcelona, Spain). The mixtures were incubated for 24 hours at 37°C and read by visual inspection. A titer 1:160 was considered consistent with brucellosis.

Hemoculture was performed by inoculation of 8–10 mL of freshly collected blood into each of a Plus aerobic/F BACTEC bottle and a Plus anaerobic/F BACTEC bottle and incubation for up to seven days in the BACTEC 9120 incubator instrument (Becton-Dickinson, Franklin Lakes, NJ).¹² Bottles were examined for the presence of growth on a 10-minute cycle by the measurement of CO₂-induced fluorescence emitted by the sensor at the bottom of the culture. Bottles giving a positive growth index were Gram stained and subcultured to chocolate and blood agar plates. Brucella isolates were identified by conventional biochemical testing.

The design and composition of the Brucella IgM and IgG flow assays have been described previously.⁷ The flow assays were obtained from Organon Teknika, Ltd. (Dublin, Ireland). The assay was performed by the addition of 5 µL of serum directly onto the sample application pad in the sample well of the plastic assay device, followed by the addition of 130 µL of running fluid. The test result was read by visual inspection for staining of the antigen and control lines in the test zone of the device. The assay was scored negative when no staining of the antigen line was observed and positive when a distinct staining of the antigen line was observed. The antigen line may stain at different intensities and was subjectively rated 1+ when staining was weak, 2+ when staining was moderate, 3+ when staining was strong, and 4+ when staining was very strong. Undetermined staining represented by very weak (+/–) staining was considered negative.

Statistical analysis. The observed agreement and the agreement beyond chance (kappa) between the results of the SAT and the flow tests was determined using Epi-Info version 6.0 (Centers for Disease Control and Prevention, Atlanta, GA). Kappa values range from -1.0 for total disagreement to +1.0 for total agreement. Agreement was considered almost perfect for values >0.8.

RESULTS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
Brucella was isolated in 39% (n = 11) and 30% (n = 10) of the hemocultures from the adult and pediatric patients with a final diagnosis of brucellosis, respectively. The SAT (titer 1:160) confirmed the clinical diagnosis of brucellosis in an additional 52 adult and 23 pediatric patients.

The results obtained in the Brucella IgM and IgG flow assays and SAT for four patients with brucellosis and one patient with a disease other than brucellosis are shown in Figure 1. The admission serum from all 11 (100%, 95% confidence interval [CI] = 68–100%) culture-positive adult patients tested positive in the IgM flow assay and 10 gave a positive result in the IgG flow assay. All 11 samples also tested positive in RB test and the SAT. The RB test, SAT, IgM flow assay, and IgG flow showed positive results in 98%, 98%, 65%, and 82%, respectively, of the total group of 54 admission sera collected from the adult patients with brucellosis (Table 1). The IgM and IgG flow assays combined gave a positive result in 49 (91%) admission sera. The IgM flow assay gave the highest number of positive results for the samples from the acute cases (83%), and this value was significant higher than that for patients with subacute (53%) and chronic (33%) disease. The IgG flow assay gave the highest number of positive results for the patients with subacute disease (94%), which was somewhat higher than that of acute (75%), chronic (78%), and relapsing (75%) cases. Clinical symptoms and signs were the same but generally were milder in patients with subacute disease than in patients with acute disease. Complications, mostly of the skeletal system, were seen in patients with chronic disease.

View larger version (86K): [in this window] [in a new window]       FIGURE 1. Brucella IgM and IgG flow assay results for admission sera collected from patients with and without brucellosis. Results obtained in the Brucella IgM and IgG flow assays and the serum agglutination test (SAT) for the admission sera from patients with acute (sample no. 1–0), subacute (sample no. 50–0), and chronic (sample no. 76–0) brucellosis, from a brucellosis patient with a relapse (sample 90–0), and from a non-brucellosis patient (sample 8–0) are shown.

View larger version (60K): [in this window] [in a new window]       FIGURE 2. Brucella IgM and IgG flow assays results for admission sera and follow-up sera collected during treatment from patients with brucellosis. Results obtained in the Brucella IgM and IgG flow assays and the serum agglutination test for the admission sample (left) and follow-up (right) for a, one patient with chronic brucellosis; b, one patient with acute brucellosis; and c and d, two patients with subacute brucellosis showing negative (neg) or weak (1+) positive results in the flow assays for the admission sera and seroconversion or an increase in staining intensity after testing of the follow-up sample collected 2-4 weeks later.

The staining intensity of the antigen band in the flow assays recorded for the admission sera from the adult and pediatric patient groups are shown in Table 2. A moderate (2+) to very strong (4+) staining intensity in either of the two assays was observed in the majority of the samples that tested positive. This was 88% (n = 43) for the adult patients with brucellosis and 81% (n = 26) for the pediatric patients. For the other positive patients, a weak (1+) test result was recorded as strongest test result. The admission sera of all (100%) culture-confirmed patients gave a moderate to very strong staining intensity in either or both flow assays.

A negative result in the flow assays was obtained for all samples including the follow-up from 23 (95.8%, 95% CI = 77–100%) of 24 adult patients admitted with clinical suspicion of brucellosis, but with a different final diagnosis (Table 1). The samples from all 10 patients with typhoid and paratyphoid fever tested negative in the flow assays. The RB test showed positive results in six (25%) patients and one of these gave a weak positive result in the IgG flow assay (Table 2). The SAT did not agglutinate or showed only an insignificant titer (1:80).

The RB test showed a positive result in the admission sera from 14 patients for whom the final diagnosis was debated (Table 1). The flow assay reacted in 13 of these RB test-positive samples, with five of them giving a moderate to very strong staining intensity. The flow assays also reacted in one RB test-negative sample. The SAT agglutinated (1:160) in seven RB test positive samples, five of which gave a 2+ staining intensity in the flow assays (Table 2).

The strength of the staining intensity of the antigen band in the flow assay showed a strong correspondence with the titer in the SAT (Table 3). The agreement between SAT (1:160) and the flow assays was 92% (kappa = 0.84, SE = 0.07) for the combined results obtained for the admission sera from the adult and pediatric patients with brucellosis, the non-brucellosis patients, and the patients with an undetermined diagnosis.

DISCUSSION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

Elevated levels of specific antibodies may remain present in patients treated for brucellosis for a long time and also may be detected in individuals exposed to the pathogen or with an inactive infection. For this reason, a higher cut-off value for the SAT is sometimes used in areas that are endemic for brucellosis.^13,14 We previously showed that reactivity in the flow assays decreases during and after treatment and that most samples collected six months or more after the start of treatment gave a negative result or a weak staining intensity.⁷ Reactivity at a low-staining intensity in the flow assays may also be observed in veterinarians exposed to the pathogen.⁷ Thus, some reactivity at low-staining intensity can be expected in the flow assay in non-brucellosis patients when using the assays in an area where brucellosis is common. A study performed among the inhabitants of five villages in Van Province demonstrated a high seroprevalence of Brucella-specific antibodies of 27% in the RB test and 27% in the SAT (titer 1:20, 8% for SAT titer 1:160).¹⁵ The flow assays reacted with a moderate (2+) to very strong (4+) staining intensity in all admission sera from the culture-confirmed adult and pediatric patients. Also, the majority of the admission sera from the culture-negative patients with brucellosis confirmed by the SAT showed a 2+ staining intensity in the flow assays, which clearly confirmed an active infection with Brucella in these patients. However a weak (1+) positive test result in the flow assays was obtained for a number of the admission sera from the culture-negative patients with brucellosis confirmed by the SAT, and a few others showed a negative test result. Testing of follow-up samples could be useful in such cases, and we were able to demonstrate sero-conversion or an increase in staining intensity in the flow assays in a number of these patients. Demonstration of sero-conversion of an increase in titer is generally accepted as strong supportive evidence for active disease. We found that 34% of the patients diagnosed with brucellosis seroconverted or showed an increase in staining intensity in the flow assays for samples collected 2-4 weeks after first diagnosis.

The adult patients with brucellosis included cases with acute, subacute, and chronic disease, and with relapse, and the flow assays performed equally well at each of these stages. However, in accordance with the notion that specific IgM antibodies are predominant during the early stages of the illness and specific IgG antibodies predominate at later stages, the sensitivity of the Brucella IgM flow assay was highest for sera collected during the acute stage and the sensitivity of the Brucella IgG flow assay was higher and a stronger staining intensity was obtained for sera collected from patients in the more progressed stages of illness. Nine percent of the admission sera from the adult patients with brucellosis tested positive in the IgM assay and negative in the IgG assay, 56% tested positive in both tests, 26% tested positive only in the IgG assay, and 9% tested negative in both tests. For the pediatric patients, these values were 9%, 67%, 21%, and 3%, respectively. Thus, although the majority of the patients may present with specific IgM as well as IgG antibodies, others may have either specific IgM or IgG antibodies. In clinical practice, the two assays should be used as complementary tests. To control costs, either of the two assays may be applied first as guided by the stage of illness. Cases with acute disease more likely are to present with a strong IgM response than cases presenting at a more progressed stage or with a relapse who are more likely to have a strong IgG reactivity.

The RB test is a very simple test that often is used as a first screening step for patients with clinical suspicion of brucellosis. The RB test-positive samples may then be tested further in the Wright agglutination test or the SAT. Screening by the RB test is also a useful strategy when the flow assays are used for confirmation. Whereas 25% of the non-brucellosis patients tested positive in the RB test, only one tested positive (1+) in the flow assays. Also, 17% of the admission sera from the patients for whom the final diagnosis was subject to debate tested positive in the RB test and of the 14 RB test-positive samples, 5 had a 2+ test result in the flow assays. Only one of the RB negative samples gave a positive result in the flow assay. This sample tested 3+ and may represent a false-positive result.

The Brucella IgM and IgG flow assays are very simple and easy to use and read. Thus, they are an attractive diagnostic alternative for field use. Following the hospitalization of several cases with severe brucellosis from a single village and the reporting of disease consistent with brucellosis in animals kept in the village, a survey team visited the village to find any additional cases of clinical or subclinical brucellosis. No clinical cases were found. Blood samples were collected from 27 villagers and tested for specific antibodies in the RB test and the SAT. Antibiotics were given to SAT-positive individuals. Laboratory testing required the transportation of the specimens to the laboratory in Van and a second visit was required to provide the antibiotics. The use of the flow assays during the survey would have allowed on-site testing and immediate treatment of positive individuals. The components of the flow assay are stable and do not need refrigeration, and the flow assay easily can be applied during a field study. The sero-prevalence was high, 44% in the RB test, 22% in the SAT, and 33% in the flow assays. It is plausible that the seropositive patients had subclinical disease at the time that the survey was held. Another explanation is that these individuals had specific antibodies due to recent exposure to the pathogen but did not develop disease. Adults living in an area endemic for brucellosis and belonging to a high risk group may well have developed a certain degree of immunity. A more detailed follow-up study would be needed to distinguish between these possibilities. Interestingly, the flow assays detected the same six individuals that tested positive in the SAT plus one individual with a low (1:40) SAT titer and two individuals whose serum samples that did not agglutinate in the SAT. Of the latter two individuals, one tested strongly (3+) positive in the IgG flow assay. We previously found several culture-confirmed patients with serum samples with low or negative SAT titers that were clearly (1+ to 4+) positive in the flow assay.⁷

The patients with brucellosis included in this study had a wide variety of non-specific clinical symptoms and signs necessitating the need for laboratory testing.¹⁶ This study confirms that the Brucella IgM and IgG flow assays present a highly convenient diagnostic alternative for culture and serologic testing by the Wright test or the SAT. The flow assays are intended for the confirmation of patients with clinical symptoms and signs consistent with brucellosis and may be used as a rapid diagnostic test in combination with the Rose Bengal test as a simple screening test. A moderate to strong positive result is highly consistent with active brucellosis. A negative or weak positive result may be confirmed by testing of a follow-up sample. The observation of reactivity in the flow assays as well as in the agglutination test in samples collected after an outbreak from individuals with no clinical illness at the time of sampling shows that some caution in the interpretation of a positive test result is needed when testing samples from high risk groups.

Received November 24, 2003. Accepted for publication February 13, 2004.

Financial support: This work was supported in part by a grant from the Hubrecht Janssen Foundation.

Authors’ addresses: Hasan Irmak, Turan Buzgan, Ömer Evirgen, Hayrettin Akdeniz, and A. Pekcan Demiroz, Department of Infectious Diseases and Clinical Microbiology, Yüzuüncü Yil University, Van, Turkey. Theresia H. Abdoel and Henk L. Smits, Koninklijk Instituut voor de Tropen Biomedical Research, Royal Tropical Institute/Koninklijk Instituut voor de Tropen, Meibergdreef 39, 1105 AZ Amsterdam, The Netherlands, Telephone: 31-20-5665470, Fax: 31-20-6971841, E-mail: h.smits{at}kit.nl.

REFERENCES

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 

1. Young EJ, 1994. An overview of human brucellosis. Clin Infect Dis 21: 283–290.
2. Daddod WA, Abdulia ZA, 2000. A panel of eight tests in the serodiagnosis and immunological evaluation of acute brucellosis. East Mediterr Health J 6: 304–312.[Medline]
3. Diaz R, Maravi-Poma E, Rivero A, 1976. Comparison of counter-immunoelectrophoresis with other serological tests in the diagnosis of human brucellosis. Bull World Health Organ 53: 417–424.[Medline]
4. Renoux G, Plommet M, Philippon A, 1971. Microreactions d’agglutination et the fixation de complement pour le diagnostics des brucelloses. Ann Rech Vet 2: 263–269.
5. Spink WW, McCullough NB, Hutchings LM, Mingle CK, 1954. A standardized antigen and agglutination technic for human brucellosis. Am J Clin Pathol 24: 496–498.[Medline]
6. Al Dahouk S, Tomaso H, Nockler K, Neubauer H, Frangoulidis D, 2003. Laboratory-based diagnosis of brucellosis-a review of the literature. Part II: serological tests for brucellosis. Clin Lab 49: 577–589.[Medline]
7. Smits HL, Abdoel TH, Solera J, Clavijo E, Diaz R, 2003. Immunochromatographic Brucella-specific immunoglobulin M and G lateral flow assays for the serodiagnosis of human brucellosis. Clin Diagn Lab Immunol 10: 1141–1146.[Abstract/Free Full Text]
8. Esel D, Doganay M, Alp E, Sumerkan B, 2003. Prospective evaluation of blood cultures in a Turkish university hospital: epidemiology, microbiology and patient outcome. Clin Microbiol Infect 9: 1038–1044.[Medline]
9. Caksen H, Arslan S, Oner AF, Cesur Y, Ceylan A, Atas B, Abuhandan M, 2002. Childhood brucellosis is still a severe problem in the eastern region of Turkey. Trop Doct 32: 91–92.[Medline]
10. Akdeniz H, Irmak H, Demiroz AP, 1998. Evaluation of brucellosis cases in Van region of wastern Anatolia: A-3 year experience. Nagoya Med J 42: 101–110.
11. Akdeniz H, Irmak H, Seckinli T, Buzgan T, Demirö z AP, 1998. Hematological manifestations in .brucellosis cases in Turkey. Acta Med Okayama 52: 63–65.
12. Gedikoglu S, Helvaci S, Ozakin C, Gokirmak F, Kilicturgay K, 1996. Detection of Brucella melitensis by BACTEC NR 730 and BACTEC 9120 systems. Eur J Epidemiol 12: 649–650.[Medline]
13. Mert A, Ozaras R, Tabak F, Bilir M, Yilmaz M, Kurt C, Ongoren S, Tanriverdi M, Ozturk R, 2003. The sensitivity and specificity of Brucella agglutination tests. Diagn Microbiol Infect Dis 46: 241–243.[ISI][Medline]
14. Memish ZA, Almuneef M, Mah MW, Qassem LA, Osoba AO, 2002. Comparison of the Brucella standard agglutination test with the ELISA IgG and IgM in patients with Brucella bacteremia. Diagn Microbiol Infect Dis 44: 129–132.[Medline]
15. Ceylan E, Irmak H, Buzgan T, Karahocagil MK, Evirgen O, Sakarya N, Akdeniz H, Demiroz AP, 2003. Van iline bagli bazi koylerde insan ve hayvan populasyonunda bruselloz seroprevalansi. Van Tip Dergisi 10: 1–5.
16. Thakur SD, Kumar R, Thapliyal DC, 2002. Human brucellosis: review of an under-diagnosed animal transmitted disease. J Commun Dis 34: 287–301.[Medline]

This article has been cited by other articles:

				M. Mendoza-Nunez, M. Mulder, M. P. Franco, K. S. J. S. M. Maas, M. L. Castaneda, N. Bonifacio, J. Chacaltana, E. Yagui, R. H. Gilman, B. Espinosa, et al. Brucellosis in Household Members of Brucella Patients Residing in a Large Urban Setting in Peru Am J Trop Med Hyg, April 1, 2008; 78(4): 595 - 598. [Abstract] [Full Text] [PDF]

				K. S. J. S. M. MAAS, M. MENDEZ, M. ZAVALETA, J. MANRIQUE, M. P. FRANCO, M. MULDER, N. BONIFACIO, M. L. CASTANEDA, J. CHACALTANA, E. YAGUI, et al. EVALUATION OF BRUCELLOSIS BY PCR AND PERSISTENCE AFTER TREATMENT IN PATIENTS RETURNING TO THE HOSPITAL FOR FOLLOW-UP Am J Trop Med Hyg, April 1, 2007; 76(4): 698 - 702. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (12) Citing Articles via Google Scholar Google Scholar Articles by IRMAK, H. Articles by SMITS, H. L. Search for Related Content PubMed PubMed Citation Articles by IRMAK, H. Articles by SMITS, H. L. Related Collections Zoonotic Diseases Brucellosis