case report role of genexpert mtb/rif assay in diagnosing...

Case ReportRole of GeneXpert MTB/Rif Assay in Diagnosing Tuberculosis inPregnancy and Puerperium

Zaiyad G. Habib,1 Farouq M. Dayyab,1 Abdallah Sanda,2

Sirajo H. Tambuwal,1 Mahmood M. Dalhat,1 Hamza Muhammad,1,3

Garba Iliyasu,1,3 Ibrahim Nashabaru,1,3 and Abdulrazaq G. Habib1,3

1 Infectious & Tropical Diseases Unit, Department of Medicine, Aminu Kano Teaching Hospital, PMB 3452,Kano 700233, Kano State, Nigeria2Department of Medical Microbiology, Aminu Kano Teaching Hospital, PMB 3452, Kano 700233, Kano State, Nigeria3College of Health Sciences, Bayero University, Kano, PMB 3011, Kano 700241, Kano State, Nigeria

Correspondence should be addressed to Abdulrazaq G. Habib; abdulrazaq [email protected]

Received 11 May 2015; Revised 22 July 2015; Accepted 27 July 2015

Academic Editor: Tomoyuki Shibata

Copyright © 2015 Zaiyad G. Habib et al.This is an open access article distributed under theCreativeCommonsAttribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Presentation of tuberculosis (TB) in pregnancy may be atypical with diagnostic challenges. Two patients with complicatedpregnancy outcomes, foetal loss and live premature delivery at 5 and 7 months of gestation, respectively, and maternal loss, werediagnosed with pulmonary TB. Chest radiography and computed tomography showed widespread reticuloalveolar infiltrates andconsolidation with cavitations, respectively. Both patients were Human Immunodeficiency Virus (HIV) seronegative and sputumsmear negative for TB. Sputum GeneXpert MTB/Rif (Xpert MTB/RIF) was positive forMycobacterium tuberculosis. To strengthenmaternal and childhood TB control, screening with same-day point-of-care XpertMTB/RIF is advocated among both HIV positivepregnant women and symptomatic HIV negative pregnant women during antenatal care in pregnancy and at puerperium.

1. Introduction

Tuberculosis (TB) diagnosismay be challenging among thosewith immunosuppressive conditions like Human Immunod-eficiency Virus (HIV) infection and pregnancy [1, 2]. Suchpatients are often anergic with negative tuberculin skin test,low sputum smear yield for acid fast bacilli (AFB), atypicalpresentations, and pregnancy related weight gain that masksTB wasting [1, 2]. Active TB is occasionally encounteredamong pregnant women in endemic countries or amongmigrant population in nonendemic countries. Given the chal-lenges in diagnosis, the time-limited nature of pregnancy, andthe caution desired prior to exposure to X-rays in conductingchest radiography, newer tools that are reliable, simple, andproven in immunosuppressive conditions and have rapidturnaround time are needed to optimize detection of TB inpregnancy. GeneXpert MTB/Rif assay (Xpert MTB/RIF) hasbeen used to diagnose TB in HIV infected patients and insputum smear negative patients [3, 4]. The World Health

Organization (WHO) guideline gave strong and conditionalrecommendations for use of Xpert MTB/RIF. The guidelinestrongly recommended use of Xpert MTB/RIF as the initialdiagnostic test in adults and children presumed to haveMDR-TB or HIV-associated TB and as the initial diagnostic test intesting cerebrospinal fluid specimens frompatients presumedto have TB meningitis. The guideline also gave conditionalrecommendations in the presence of major resource implica-tions.This conditional recommendation includes usingXpertMTB/RIF as the initial diagnostic test in adults and childrenpresumed to have TB and as a follow-on test to microscopyin adults presumed to have TB but not at risk of MDR-TBor HIV-associated TB especially in further testing of smearnegative specimens. Xpert MTB/RIF can also be used con-ditionally as a replacement test for usual practice (includingconventional microscopy, culture, and/or histopathology) fortesting of specific nonrespiratory specimens (lymph nodesand other tissues) from patients presumed to have extra-pulmonary TB [5]. In a study in Zambia among inpatients

Hindawi Publishing CorporationCase Reports in Infectious DiseasesVolume 2015, Article ID 794109, 5 pageshttp://dx.doi.org/10.1155/2015/794109

2 Case Reports in Infectious Diseases

with a primary obstetrics or gynaecological problem thathad concomitant cough, Xpert MTB/RIF when compared tostandard sputum smear microscopy, MTB culture, and MTBdrug susceptibility testing provided a reasonably sensitive,specific, and rapid method for diagnosing pulmonary TB inobstetrics and gynaecological patients. Out of the 27.7% ofculture confirmed cases of pulmonary TB from the study,Xpert MTB/RIF assay had a sensitivity of 80.8% comparedwithMTB culturewhile sputum smearmicroscopy had a sen-sitivity of 50.0% compared with the MTB culture [6]. In ourstudy, we described the use of Xpert MTB/RIF in diagnosingpulmonary TB in patients with complicated pregnancy andpuerperium and discuss the implications for maternal andchild health.

2. Case 1

2.1. Day 0 of Admission. The first case was that of a 24-year-old booked primigravida who presented a few days fol-lowing abortion at 5 months of gestation to the infectiousdiseases clinic with breathlessness, cough, and fever of 2-week duration following evacuation for incomplete abortion.There was history of weight loss and haemoptysis. Whenexamined shewas found to be pale and febrile (Temperature =39.5∘C axillary). She was tachycardic with a pulse rate of 120beats per minute; blood pressure was 90/70mmHg and shehad normal heart sounds. She was also tachypnoeic (res-piratory rate: 32 cycles per minute) with oxygen saturationof 70% on room air. She had coarse crackles and bronchialbreathing. Differentials considered were severe communityacquired pneumonia, sepsis secondary to pelvic infection,and pulmonary embolism secondary to pelvic inflammatorydisease with pelvic thromboembolism.

Investigations requested include full blood count (FBC),erythrocyte sedimentation rate (ESR), chest radiograph, spu-tum microscopy and culture for bacteria, sputum for fungalstudy, sputum smear and microscopy for acid fast bacilli,blood culture, Doppler ultrasound of the pelvis and lowerlimbs, electrocardiogram (ECG), urea and electrolytes, urinemicroscopy, culture and sensitivity, urinary pregnancy test,and HIV screening.

She was commenced on initial empiric therapy of pipera-cillin-tazobactam, doxycycline, gentamicin, intravenous flu-ids, and oxygen supplementation. Vancomycin and enoxa-parin were subsequently added.

2.2. Initial Results Obtained on Day of Admission. Electrocar-diography (ECG) showed sinus tachycardia with no diag-nostic features of pulmonary embolism and screening forHIV was negative. Initial full blood counts (FBC) showedwhite blood cell counts (WBC) of 9.7 × 109/L, neutrophilsof 84.6%, lymphocytes of 11.9%, haematocrit (HCT) of 37%,and platelets of 273 × 109/L. Preliminary sputum Gram stainshowed Gram negative bacilli and Gram positive cocci. Dop-pler ultrasound scan of the lower limbs was negative for deepvenous thrombosis of calf veins. Chest radiograph showedglobal infiltrates reported by radiologist as reticuloalveolar“miliary” shadows (Figure 1).

Figure 1: Chest radiograph showing widespread (whole lung) retic-uloalveolar “miliary” infiltrates.

2.3. Day 1 of Admission. Patient was still febrile (Tempera-ture = 38.0∘C axillary). Her vital signs showed respiratory rateof 48 cycles/minute, pulse rate of 140, and blood pressure of86/60mmHg. She was still on oxygen supplementation andpulse oximetry (SpO

2) was 93%.

Three sputum smears for acid fast bacilli (AFB) werenegative. Urinary pregnancy test also came back negative.GeneXpert MTB/Rif was ordered.

Her treatment was continued and doxycycline was dis-continued.

2.4. Day 2 of Admission. Patient was still febrile, tachypnoeic,tachycardic, and hypotensive.

Sputum microscopy and culture for fungal pathogenswere negative.Microscopy for bacteria showedGrampositivediplococci and Gram negative bacilli and Streptococcus pneu-moniae was cultured from the sputum. Piperacillin-tazobac-tam was substituted with levofloxacin based on sensitivityresults. Automated blood cultures yielded no growth.

GeneXpert MTB/Rif version 5.0 Cepheid assay (XpertMTB/RIF) was positive for Mycobacterium tuberculosis withno detectable rifampicin resistance. Patient remained pyrexicand tachypnoeic for 3 days despite antibiotics. She was thencommenced on four-drug anti-TB therapy (rifampicin, isoni-azid, pyrazinamide, and ethambutol).

2.5. Day 4 of Admission. Two days after commencing anti-TB therapy, patient was less dyspnoeic and afebrile (Tempera-ture = 37.1∘C axillary); SPO

2rose to 89% on room air and 98%

on oxygen supplementation.Though she was still tachycardicwith a radial pulse rate of 128 beats per minute, her bloodpressure rose to 100/70mmHg.

FBC done showed WBC of 8.1 × 109/L, neutrophils of74.9%, lymphocytes of 14.5%,HCTof 32.3%, platelets of 307×109/L, and erythrocyte sedimentation rate (ESR) of 20mm/hr.

2.6. Day 5 of Admission. Patient suddenly desaturated in theevening with breathlessness and shock and subsequently

Case Reports in Infectious Diseases 3

died. An autopsy could not be performed on the patient dueto the religious belief of the patient as she was a Muslim andit was required that she should be buried immediately upondeath.

3. Case 2

3.1. Day 0 of Admission. A 27-year-old primipara presented2 weeks after a spontaneous vaginal delivery of a live babywith a 6-week history of productive cough, associated rightsided pleuritic chest pain with no haemoptysis. The coughbecame exacerbated following delivery.There were low gradeintermittent fever and drenching night sweats with initialonset of symptoms 6 weeks to presentation. The pregnancywas booked. She had a live preterm delivery at 7 months ofgestation. At presentation she was febrile (Temperature =38.8∘C axillary), had left supraclavicular lymphadenopathy,tachypnoea (28 cycles per minute), and bibasal crackles, andwas also tachycardic (146 beats per minute). Differentialsconsidered were community acquired pneumonia, sepsis,pulmonary embolism, and pulmonary tuberculosis.

Investigations requested include full blood count (FBC),erythrocyte sedimentation rate (ESR), chest radiograph, spu-tum microscopy and culture for bacteria, sputum for fungalstudy, sputum smear and microscopy for acid fast bacilli,blood culture, pelvic ultrasound, electrocardiogram (ECG),urea and electrolytes, urine microscopy, culture and sensitiv-ity, high vaginal swab (HVS) culture, and HIV screening.Thepatient was commenced on empiric ceftriaxone, ciprofloxa-cin, enoxaparin, and an intravenous infusion and also had astat dose of vancomycin.

3.2. Day 1 of Admission. Patient was still febrile, tachypnoeic,and tachycardic.

Her initial results showedWBC of 4.8 × 109/L, haemoglo-bin of 11.8 g/L, platelets of 164 × 109/L, and ESR of 130mm/hr,with normal electrolytes and liver function tests. Chest X-ray showed streaky opacities in the left mid and lower zones.Preliminary sputum smear showed Gram positive cocci inchains and Gram negative rods. Pelvic ultrasound showedretained products. ECG showed sinus tachycardia. Viralscreening for HIV, hepatitis B, and hepatitis C was negative.

Clindamycin was added to her treatment as well as astat dose of gentamicin. Ceftriaxone and vancomycin werehowever stopped to continue with ciprofloxacin.

Patient also had manual vacuum aspiration (MVA) donewhere about 80mL of products was removed.

3.3. Day 2 of Admission. Patient was still febrile, tachypnoeic,and tachycardic and still complaining of right sided pleuriticchest pain.

3.4. Day 5 of Admission. Patient was still febrile; sputumculture revealed ESBLKlebsiella pneumoniae sensitive to onlyimipenem and meropenem; hence meropenem was com-menced. All other cultures yielded no growth. Three sputumZiehl-Neelsen stains were also negative.

Figure 2: Chest CT scan showing consolidation with “cavities” inthe right posterior lung base.

3.5. Day 8 of Admission. Thepatient was still febrile (Temper-ature = 39.5∘C axillary) and coughing and still having tachy-cardia.

Further investigations were done with the followingresults: 2D-echocardiogram showed pericarditis with mini-mal effusion. She had serum D-dimer of 734.46 ng/mL (0–500 ng/mL), negative serum antinuclear antibody (ANA).

Spiral chest CT Scan excluded pulmonary arterial embo-lism but showed a well-defined fairly rectangular area ofparenchymal density (HU: 11–36) that had scattered areas ofhypoattenuation “cavitations” within it, seen in the posterioraspect of the right basal lung zone (Figure 2).

Xpert MTB/RIF done detectedMycobacterium tuberculo-siswith no rifampicin resistance. A diagnosis of disseminatedTB involving lungs, lymph nodes, and pericardium wasconsidered. The patient received four-drug antituberculousmedication (rifampicin, isoniazid, ethambutol, and pyrazi-namide) with dramatic defervescence after 4 days and notice-able gradual improvement. Ethambutol was later stoppedwhen the patient developed visual side effects 7 days afterits commencement. Follow-up of patient at just four weeksof treatment showed WBC of 3.4 × 109/L, haemoglobin of11.8 g/L, platelets of 352 × 109/L, and ESR of 55mm/hr. Herserum electrolytes and liver function tests remained normal.She was discharged and had complete six months of antitu-berculous medication. Posteroanterior and lateral chest radi-ographs at completion of medication showed clear lung fieldswith complete resolution of the lesion on the posterior aspectof the right basal lung zone (Figures 3(a) and 3(b), resp.).

4. Discussion

The cases presented described the diagnosis of TB by GeneX-pert MTB/Rif assay (Xpert MTB/RIF) in two women who areHIV negative following abortion and live preterm delivery,respectively. The first patient had a chest radiograph consis-tent withmiliary TBwhile the second patient had nonspecificchest radiograph changes with chest CT scan however having

4 Case Reports in Infectious Diseases

(a) (b)

Figure 3: Posteroanterior and lateral chest radiograph, respectively, showing clear lung fields after completion of six-month antituberculousmedication.

features suggestive of pulmonary TB. Sputum smear was neg-ative for AFB in both cases.The second patient had markedlyelevated ESR. Doppler ultrasound, ECG, and chest spiralcomputed tomography excluded deep venous thrombosisand pulmonary embolism. The patients were treated withantibiotics for presumed sepsis (community acquired pneu-monia and pelvic inflammatory disease) with no response.Streptococcus pneumoniae and Klebsiella pneumoniae were,respectively, cultured in the sputum of the cases and werelikely super added acute bacterial infections. However, thesymptoms and radiographic lesions actually persisted orworsened despite follow-up culture after antibiotic courseyielding no growth. Subsequently, commencement of anti-TBtherapy led to immediate resolution of symptoms with grad-ual improvement of the second patient but unfortunately ledto worsening of symptoms and a fatal outcome in the firstpatient which likely could have been from overwhelming TBor immune reconstitution reaction.

Diagnosis of TB in immunocompromised states like HIVand pregnancy could be challenging as sputum smear AFByield is often poor [1, 2]. Indeed in a study of 602 HIV-associated TB patients, sputum smear had a low sensitivity of26.7% compared to Xpert MTB/RIF with >80%. It remainedsensitive even among those with severe or advanced diseasewith low CD4 counts of <100 cells/𝜇L while only 15% wereculture positive [3]. Similarly, in a study conducted amongobstetrics and gynaecology patients, a sensitivity of 80.8%from Xpert MTB/RIF compared to about 50% from sputumsmear was reported; hence as an alternative to sputummicroscopy, Xpert MTB/RIF provides a sensitive, specific,and rapid method for the diagnosis of pulmonary TB amongobstetric and gynaecological patients [6]. Although ourpatients were HIV seronegative and had chest radiographand chest CT scan suggestive of pulmonary TB, respectively,immunosuppressed patients from any cause including preg-nancy often present with atypical chest radiographs. Lesionsare found in unusual locations as in the second case and

Xpert MTB/RIF in this instance provides a more accurate TBdiagnosis than chest radiography [7].

As typified by our patients who had radioimaging onlyafter delivery, clinicians often are cautious in conducting radi-ography and computed tomography during pregnancy due toconcerns of potential untoward effects of exposure to radi-ation to the foetus. This further precludes the opportunityto detect TB timely during pregnancy and can lead to eitherpremature delivery, foetal loss, and/or maternal loss as seenin the two cases.

Indeed, diagnosis of TB and commencement of therapywere delayed in the first case that had pregnancy loss andeventually proved fatal to themother. Even though symptomspreceded delivery by a prolonged period, diagnosis in thesecond patient was also delayed until puerperium withpotential risk of vertical transmission to the baby. Howeverafter thorough evaluation there was no evidence of verticaltransmission of TB to the baby in the second case. Comparedto sputum smear, Xpert MTB/RIF has been shown to havea higher sensitivity to detect TB much more rapidly insputum smear negative patients and in such cases whereculture has to be relied upon, Xpert MTB/RIF reduces themedian time of making a diagnosis of TB by 29 days amongsuspected patients [8]. Reasonably accurate and reliableresults may be available within hours or within a day withXpert MTB/RIF. Potentially smear microscopy combinedwith Xpert MTB/RIF provides an opportunity for strength-ening TB screening during ANC among both symptomaticand asymptomatic pregnant women. At population level thecombination of the two approaches has been found to becomplementary and synergistic [9]. A potential platform atthe ANC will be to situate the two tests in the context of Pre-vention of Mother-to-Child Transmission (PMTCT) of HIVinfection [6, 9, 10]. If logistics are properly managed the assaycan be conducted as a point-of-care same-day test and ther-apy commenced for those confirmed positive. Already suchANC point-of-care same-day rapid HIV tests are offered.

Case Reports in Infectious Diseases 5

A similar immunochromatographic syphilis test has beenintroduced and its scale-up in Sub-Saharan Africa is beingexplored for the control of maternal and congenital syphilis[11]. Both cases occurred after delivery or in puerperium anda recent large study showed that early postpartum womenare twice as likely to develop TB as nonpregnant women [2].Therefore, screening for TBmay need to be continued duringpuerperium.

Automated liquid or solid TB culture and drug suscep-tibility testing will confirm the diagnosis but take a muchlonger period of at least about 2 or 6–8 weeks, respectively.

Xpert MTB/RIF can also detect rifampicin resistance, apredictor of multidrug resistant TB. As many of the second-line drugs are relatively toxic and unsafe in pregnancy,information on drug resistance will be crucial in guidingselection of appropriate second-line anti-TBmedications andfacilitating optimummanagement of mother and child.

Even in Sub-Saharan Africa with a low ANC coverage,23.5 million (74%) of 32 million annual live births were fromwomen reported to have had at least oneANCvisit [11]; point-of-care same-day ANC Xpert MTB/RIF has the potentialto reduce mother-to-child transmission of Mycobacteriumtuberculosis while strengthening existing TB control in neo-natal period as case detection will be conducted more timely.Mothers and babies detected could be commenced on anti-TB therapy promptly and isoniazid preventive therapy maybe offered to unaffected children of mothers on treatmentfollowed by BCG vaccination.

In conclusion, two women with poor pregnancy out-comes, foetal loss and live preterm delivery and maternalloss, were diagnosed with pulmonary TB. Maternal mortalityresulted in the first patient. Sputum smear was negative anddiagnosis of TB was by Xpert MTB/RIF with suggestive chestradiograph and chest CT scan for the first and the secondpatients, respectively. To strengthen maternal and childhoodTB control, screening with same-day point-of-care XpertMTB/RIF is advocated among symptomatic women duringpregnancy and puerperium.

Ethical Approval

The study and report have been performed in accordancewith the ethical standards laid down in the 1964 DeclarationofHelsinki and its later amendments. Patients’ confidentialityis maintained throughout.

Conflict of Interests

On behalf of all the authors, the corresponding author statesthat there is no conflict of interests regarding the publicationof this paper. This report has not been submitted to anotherjournal for consideration.

Authors’ Contribution

All authors have approved the final version of the paper.

References

[1] A. G. Habib, “A clinical and epidemiologic update on theTuberculosis and HIV infection interaction in adults,” Annalsof African Medicine, vol. 8, pp. 153–161, 2009.

[2] D. Zenner,M. E. Kruijshaar,N.Andrews, and I. Abubakar, “Riskof tuberculosis in pregnancy: a national, primary care basedcohort and self-controlled case-series study,” American Journalof Respiratory andCritical CareMedicine, vol. 185, no. 7, pp. 779–784, 2012.

[3] S. D. Lawn, A. D. Kerkhoff, M. Vogt, and R. Wood, “HIV-associated tuberculosis: relationship between disease severityand the sensitivity of new sputum-based and urine-based diag-nostic assays,” BMCMedicine, vol. 11, article 231, 2013.

[4] L. Nakiyingi, H. Nankabirwa, and M. Lamorde, “Tuberculosisdiagnosis in resource-limited settings: clinical use of GeneXpertin the diagnosis of smear-negative PTB: a case report,” AfricanHealth Sciences, vol. 13, no. 2, pp. 522–524, 2013.

[5] World Health Organization, “Xpert MTB/RIF assay for thediagnosis of pulmonary and extra pulmonary TB in adults andchildren—policy update,” Tech. Rep. WHO/HTM/TB/2013.16,WHO, Geneva, Switzerland, 2013.

[6] M. Bates, Y. Ahmed, L. Chilukutu et al., “Use of the XpertMTB/RIF assay for diagnosing pulmonary tuberculosis comor-bidity and multidrug-resistant TB in obstetrics and gynaecol-ogy inpatientwards at theUniversity TeachingHospital, Lusaka,Zambia,” TropicalMedicine and International Health, vol. 18, no.9, pp. 1134–1140, 2013.

[7] C. Wekesa, B. J. Kirenga, M. L. Joloba, F. Bwanga, A. Katamba,andM. R. Kamya, “Chest X-ray vs. XpertMTB/RIF assay for thediagnosis of sputum smear-negative tuberculosis in Uganda,”International Journal of Tuberculosis and Lung Disease, vol. 18,no. 2, pp. 216–219, 2014.

[8] G. Theron, J. Peter, R. Meldau et al., “Accuracy and impact ofXpert MTB/RIF for the diagnosis of smear-negative or sputum-scarce tuberculosis using bronchoalveolar lavage fluid,”Thorax,vol. 68, no. 11, pp. 1043–1051, 2013.

[9] D.W.Dowdy, J. L. Davis, S. den Boon,N.D.Walter, A. Katamba,and A. Cattamanchi, “Population-level impact of same-daymicroscopy and Xpert MTB/RIF for tuberculosis diagnosis inAfrica,” PLoS ONE, vol. 8, no. 8, Article ID e70485, 2013.

[10] E. R. Turnbull, N. G. Kancheya, J. B. Harris, S. M. Topp, G.Henostroza, and S. E. Reid, “A model of tuberculosis screeningfor pregnant women in resource-limited settings using xpertMTB/RIF,” Journal of Pregnancy, vol. 2012, Article ID 565049,5 pages, 2012.

[11] A. Kuznik, M. Lamorde, A. Nyabigambo, and Y. C. Manabe,“Antenatal Syphilis screening using point-of-care testing in Sub-Saharan African countries: a cost-effectiveness analysis,” PLoSMedicine, vol. 10, no. 11, Article ID e1001545, 2013.

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