Articles tagged as "Avoid TB deaths"

Anaemia? Think TB!

Predictive value of anemia for tuberculosis in HIV-infected patients in sub-Saharan Africa: an indication for routine microbiological investigation using new rapid assays.  

Kerkhoff AD, Wood R, Vogt M, Lawn SD. J Acquir Immune Defic Syndr. 2014 May 1;66(1):33-40. doi: 10.1097/QAI.0000000000000091.

Background: The relationship between anemia and undiagnosed tuberculosis (TB) in patients living with HIV in sub-Saharan Africa is incompletely defined. We assessed the prevalence of TB among those with HIV-related anemia and evaluated new means of rapid TB diagnosis.

Methods: Blood hemoglobin levels were measured in unselected antiretroviral treatment-naive patients in Cape Town, South Africa, and anemia was classified according to World Health Organization criteria. All patients were screened for TB by testing paired sputum samples using liquid culture (reference standard), fluorescence microscopy, and Xpert MTB/RIF. Urine samples were tested for lipoarabinomannan (LAM) using the Determine TB-LAM diagnostic assay.

Results: Of 602 adults screened, 485 had complete results. Normal hemoglobin levels were found in 44.5% (n = 216) of patients, and mild, moderate, or severe anemia were present in 24.9% (n = 121), 25.4% (n = 123) and 5.2% (n = 25) of patients, respectively. Culture-confirmed pulmonary TB was diagnosed in 8.8% (19/216) of those without anemia compared with 16.5% (20/121), 26.0% (32/123), and 40.0% (10/25) among those with mild, moderate, or severe anemia, respectively (P < 0.001). Anemia was a strong independent predictor of TB. The sensitivities of diagnostic assays were much higher among those with moderate/severe anemia compared with those with no/mild anemia using sputum microscopy (42.9% vs 15.4%), urine LAM (54.8% vs 0%), sputum microscopy plus urine LAM (71.4% vs 15.4%), and sputum Xpert (73.8% vs 41.0%) (P < 0.01 for all).

Conclusions: A very high prevalence of undiagnosed TB was found in patients with moderate or severe anemia. Such patients should be prioritized for routine microbiological investigation using rapid diagnostic assays.

Abstract access 

Editor’s notes: Tuberculosis remains a leading cause of illness and death among people living with HIV. Tuberculosis is harder to diagnose among HIV-positive people. They are less likely to have high concentrations of Mycobacterium tuberculosis in their sputum, and more likely to have disease outside the lungs. Xpert MTB/RIF, a new rapid assay for tuberculosis, has better sensitivity than sputum smear microscopy. However, its sensitivity among HIV-positive people remains suboptimal. This study, among antiretroviral-naïve people in South Africa, illustrates the strong association between anaemia and active tuberculosis. The results support previous recommendations that tuberculosis should be considered among HIV-positive people with anaemia. Anaemia could be used, in combination with other markers, to identify people at highest risk of tuberculosis who would benefit from intensified investigation or empirical tuberculosis treatment. These approaches are being investigated in ongoing clinical trials.   

Avoid TB deaths
Comorbidity
Africa
South Africa
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Antiretroviral therapy for TB/HIV in South Africa

The impact of ART on TB case fatality stratified by CD4 count for HIV-positive TB patients in Cape Town, South Africa (2009-2011).

Kaplan R, Caldwell J, Middelkoop K, Bekker LG, Wood R. J Acquir Immune Defic Syndr. 2014 May 12. [Epub ahead of print]

Objective: To identify determinants of TB case fatality including the impact of antiretroviral therapy (ART) at different CD4 thresholds for HIV-positive adult and adolescent TB patients.

Methods: Through a retrospective analysis of the electronic TB database, we identified the HIV status of newly registered patients ≥15 yrs. Multivariable Cox proportional hazard models were used to determine risk factors for TB case fatality in these patients.

Results: In 2009, 2010 and 2011, 25 841, 26 104 and 25 554 newly registered adult TB patients were treated in primary health care clinics in Cape Town, of whom 49.7%, 50.4% and 50.9% were HIV-positive. ART uptake increased over the three years from 43% to 64.9% and case fatality of the HIV-positive patients decreased from 7.0% to 5.8% (p<0.001). Female gender, increasing age, retreatment TB, low CD4 counts and extrapulmonary TB (EPTB) were associated with increased case fatality while patients on ART had a substantial decrease in case fatality. The difference in case fatality between patients on ART and not on ART was most pronounced at low CD4 counts with the positive influence of ART noted up to a CD4 count threshold of 350cells/mm (p<0.001). Despite improvements in ART uptake, in 2011, 21% of patients with CD4 counts <350cells/mm did not start ART during TB treatment.

Conclusion: This study showed a relatively poor uptake of ART among severely immune-compromised TB patients. Patients with CD4 counts <350cells/mm were shown to clearly benefit from ART during TB treatment and ART initiation should be prioritised for this category of patients.

Abstract access 

Editor’s notes: Although WHO guidelines recommend that antiretroviral therapy (ART) be given to all people with HIV-associated TB, regardless of CD4 cell count, the evidence base for this recommendation is limited for people with higher CD4 cell counts. South African national guidelines provide ART up to a CD4 count threshold of 350 cells/µL. This retrospective observational analysis of the Electronic TB Register for Cape Town, South Africa, reported on outcomes of 38 996 people with HIV-associated TB treated over a three-year period. In multivariable analyses, receipt of ART was associated with an approximate halving of mortality risk and benefit was seen for all CD4 count categories below a threshold of 350 cells/µL. At CD4 counts above this level, case fatality rates among HIV-positive people not on ART were not higher than rates among HIV-negative people with TB, suggesting limited potential for benefit from ART. Coverage under the South African guidelines was incomplete, with one-fifth of people failing to start ART. This study clearly illustrates the benefits of testing people with TB for HIV and providing ART for those testing HIV-positive with CD4 counts up to 350 cells/µL.

Avoid TB deaths
Comorbidity, HIV Treatment
Africa
South Africa
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Hunting for HIV and TB in households

Incidence of TB and HIV in prospectively followed household contacts of TB index patients in South Africa.

van Schalkwyk C, Variava E, Shapiro AE, Rakgokong M, Masonoke K, Lebina L, Welte A, Martinson N. PLoS One. 2014 Apr 23;9(4):e95372. doi: 10.1371/journal.pone.0095372. eCollection 2014.

Objective: To report the incidence rates of TB and HIV in household contacts of index patients diagnosed with TB.

Design: A prospective cohort study in the Matlosana sub-district of North West Province, South Africa.

Methods: Contacts of index TB patients received TB and HIV testing after counseling at their first household visit and were then followed up a year later, in 2010. TB or HIV diagnoses that occurred during the period were determined.

Results: For 2 377 household contacts, the overall observed TB incidence rate was 1.3 per 100 person years (95% CI 0.9-1.9/100py) and TB incidence for individuals who were HIV-infected and HIV seronegative at baseline was 5.4/100py (95% CI 2.9-9.0/100py) and 0.7/100py (95% CI 0.3-1.4/100py), respectively. The overall HIV incidence rate was 2.2/100py (95% CI 1.3-8.4/100py).

Conclusions: In the year following a household case finding visit when household contacts were tested for TB and HIV, the incidence rate of both active TB and HIV infection was found to be extremely high. Clearly, implementing proven strategies to prevent HIV acquisition and preventing TB transmission and progression to disease remains a priority in settings such as South Africa.

 Abstract  Full-text [free] access

Editor’s notes: This study was conducted at the epicentre of the African HIV and TB epidemics in southern Africa. It provides important confirmatory data of the high incidence of new HIV infections and of TB in household contacts of index TB cases. These data provide an evidence base for planning household-based programmes with active TB case finding and HIV screening in this population. Unsurprisingly, TB incidence was 7.7-fold higher in HIV-positive household contacts, re-emphasizing the importance of simultaneous active screening for these diseases. 

Avoid TB deaths
Comorbidity, Epidemiology
Africa
South Africa
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Incremental yield of urine lipoarabinomannan (LAM) for rapid TB diagnosis

Comparative performance of urinary lipoarabinomannan assays and Xpert MTB/RIF in HIV-infected individuals with suspected tuberculosis in Uganda.

Shah M, Ssengooba W, Armstrong D, Nakiyingi L, Holshouser M, Ellner JJ, Joloba M, Manabe YC, Dorman SE. AIDS. 2014 Mar 15. [Epub ahead of print]

Background: Xpert MTB/RIF ('Xpert') and urinary lipoarabinomannan (LAM) assays offer rapid tuberculosis (TB) diagnosis, but have suboptimal sensitivity when used individually in HIV-positive patients. The yield of these tests used in combination for the diagnosis of active TB among HIV-infected TB suspects is unknown.

Design: Study of comparative diagnostic accuracy nested into a prospective study of HIV-infected individuals with signs and/or symptoms of TB in Uganda.

Methods: Xpert testing of archived sputum was conducted for culture-confirmed TB cases and TB suspects in whom a diagnosis of TB was excluded. Additional testing included sputum smear microscopy, sputum culture (solid and liquid media), mycobacterial blood culture, and urinary testing for LAM using a lateral flow test ('LF-LAM') and an enzyme-linked immunosorbance assay ('ELISA-LAM').

Results: Among 103 participants with culture-confirmed TB, sensitivity of Xpert was 76% (95% confidence interval, CI 0.66-0.84), and was superior to that of LF-LAM (49%, 95% CI 0.39-0.59, P < 0.001). Specificity was greater than 97% for both tests among 105 individuals without TB. The combination of smear microscopy and LF-LAM identified 67% (95% CI 0.57-0.76) of culture-confirmed TB cases and approached sensitivity of Xpert testing alone (P = 0.15). The sensitivity of the combination of Xpert and LF-LAM was 85% (88/103 95% CI 0.77-0.92), which was superior to either test alone (P < 0.05) and approached sensitivity of sputum liquid culture testing (94%, 95% CI 0.88-0.98, P = 0.17).

Conclusion: Sputum Xpert and urinary LAM assays were complementary for the diagnosis of active TB in HIV-infected patients, and sensitivity of the combination of these tests was superior to that of either test alone.

Abstract access

Editor’s notes: The Determine TB-LAM Ag (tuberculosis- lipoarabinomannan) assay is a rapid, low-cost, lateral-flow ‘dip-stick’ test that can be conducted at the point-of-care for diagnosis of HIV-associated tuberculosis (TB). The sensitivity of the assay is insufficient for it to be used as a stand-alone test. However, this study shows that the urine LAM assay has ‘added value’ when used in combination with sputum-based testing. It provides increased sensitivity when used in combination with either sputum microscopy or with sputum Xpert Mycobacterium tuberculosis/ rifampicin (MTB/RIF) testing. This study adds to the growing evidence base supporting the use of urine LAM assays for rapid TB diagnosis in individuals with advanced immunodeficiency.

Avoid TB deaths
Comorbidity
Africa
Uganda
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Urine lipoarabinomannan (LAM) detection for rapid TB diagnosis

Diagnostic accuracy of a rapid urine lipoarabinomannan test for tuberculosis in HIV-infected adults.

Nakiyingi L, Moodley VM, Manabe YC, Nicol MP, Holshouser M, Armstrong DT, Zemanay W, Sikhondze W, Mbabazi O, Nonyane BA, Shah M, Joloba ML, Alland D, Ellner JJ, Dorman SE. J Acquir Immune Defic Syndr. 2014 Mar 26. [Epub ahead of print]

Design: Prospective diagnostic accuracy study.

Setting: Hospital and outpatient settings in Uganda and South Africa.

Participants: HIV-infected adults with tuberculosis symptoms and/or signs.

Methods: Participants provided a fresh urine specimen for TB LAM testing, blood for mycobacterial culture, and two respiratory specimens for smear microscopy and mycobacterial culture.

Main outcome measures: For the TB LAM test, sensitivity in participants with culture-positive tuberculosis and specificity in participants without tuberculosis.

Results: 1 013 participants were enrolled. Among culture-positive tuberculosis patients, the TB LAM test identified 136/367 (37.1%) overall and 116/196 (59.2%) in the group with CD4 ≤ 100 cells/mm. The test was specific in 559/573 (97.6%) of patients without tuberculosis. Sensitivity of the urine TB LAM test plus sputum smear microscopy was 197/367 (53.7%) overall and 133/196 (67.9%) among those with CD4≤100. CD4≤50 (adjusted odds ratio [AOR] 6.2, P<0.001) or 51-100 (AOR 7.1, P<0.001), mycobacteremia (AOR 6.1; P<0.01) and hospitalization (AOR 2.6, P=0.03) were independently associated with a positive TB LAM test.

Conclusions: In HIV-positive adults with CD4≤100, the TB LAM urine test detected over half of culture-positive tuberculosis patients, in less than 30 minutes and without the need for equipment or reagents.

Abstract access 

Editor’s notes: The Determine TB - LAM Ag assay (tuberculosis- lipoarabinomannan) is a rapid, low-cost, lateral-flow ‘dip-stick’ test that can be conducted at the point-of-care for diagnosis of HIV-associated tuberculosis (TB). This is an important confirmatory study. It shows that useful sensitivity is restricted to individuals with advanced immunodeficiency (CD4 count <100 cells/µl) in whom the assay detects approximately one half of cases with high specificity. Although the sensitivity is limited, a key point is that the assay provided rapid TB diagnosis in the sub-set of people who were most sick and likely to have had highest mortality risk.  These individuals include those with the lowest CD4 cell counts, individuals with mycobacteraemia and hospital in-patients.  This is a promising add-on diagnostic test for HIV-associated TB.

Avoid TB deaths
Comorbidity
Africa
South Africa, Uganda
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Door-to-door active tuberculosis case finding using smear microscopy and targeted Xpert, is feasible and effective in urban slums in Cambodia

Community-based active tuberculosis case finding in poor urban settlements of Phnom Penh, Cambodia: a feasible and effective strategy.

Lorent N, Choun K, Thai S, Kim T, Huy S, Pe R, van Griensven J, Buyze J, Colebunders R, Rigouts L, Lynen L. PLoS One. 2014 Mar 27;9(3):e92754. doi: 10.1371/journal.pone.0092754. eCollection 2014.

Background: In light of the limitations of the current case finding strategies and the global urgency to improve tuberculosis (TB) case-detection, a renewed interest in active case finding (ACF) has risen. The WHO calls for more evidence on innovative ways of TB screening, especially from low-income countries, to inform global guideline development. We aimed to assess the feasibility of community-based ACF for TB among the urban poor in Cambodia and determine its impact on case detection, treatment uptake and outcome.

Methods: Between 9/2/2012-31/3/2013 the Sihanouk Hospital Center of HOPE conducted a door-to-door survey for TB in deprived communities of Phnom Penh. TB workers and community health volunteers performed symptom screening, collected sputum and facilitated specimen transport to the laboratories. Fluorescence microscopy was introduced at three referral hospitals. The GeneXpert MTB/RIF assay (Xpert) was performed at tertiary level for individuals at increased risk of HIV-associated, drug-resistant or smear-negative TB. Mobile phone/short message system (SMS) was used for same-day issuing of positive results. TB workers contacted diagnosed patients and referred them for care at their local health centre.

Results: In 14 months, we screened 315 874 individuals; we identified 12 201 aged ≥15 years with symptoms suggestive of TB; 84% provided sputum. We diagnosed 783, including 737 bacteriologically confirmed, TB cases. Xpert testing yielded 41% and 48% additional diagnoses among presumptive HIV-associated and multidrug-resistant TB cases, respectively. The median time from sputum collection to notification (by SMS) of the first positive (microscopy or Xpert) result was 3 days (IQR 2-6). Over 94% commenced TB treatment and 81% successfully completed it.

Conclusion: Our findings suggest that among the urban poor ACF for TB, using a sensitive symptom screen followed by smear-microscopy and targeted Xpert, contributed to improved case detection of drug-susceptible and drug-resistant TB, shortening the diagnostic delay, and successfully bringing patients into care.

Abstract   Full-text [free] access

Editor’s notes: A significant proportion of tuberculosis (TB) remains undiagnosed despite widespread implementation of “directly observed treatment, short-course” (DOTS) in high TB/HIV burden settings.  This has led to a renewed interest in systematic screening for active TB to improve case detection, reduce the risk of poor health and poor socio-economic outcomes and reduce transmission.  Arguments against the implementation of systematic screening for tuberculosis in high burden settings include uncertain impact on treatment outcomes and transmission, high cost and poor sustainability. This study demonstrates that community-based, door-to-door active case finding through community health workers, with targeted use of Xpert, plus smear microscopy was feasible and effective in poor urban settlements in Cambodia.  The use of mobile phone/short messaging service (SMS) was good, contributing to expediting time to diagnosis and linkage to care, although no formal cost-effectiveness study was undertaken. Longer-term follow-up data are needed to evaluate the impact on transmission.

Avoid TB deaths
Comorbidity, Epidemiology
Asia
Cambodia
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HIV, antiretroviral therapy and presentation of TB

The effect of HIV and antiretroviral therapy on characteristics of pulmonary tuberculosis in northern Malawi: a cross-sectional study

Munthali L, Khan PY, Mwaungulu NJ, Chilongo F, Floyd S, Kayange M, Glynn JR, French N, Crampin AC. BMC Infect Dis. 2014 Feb 25;14(1):107. doi: 10.1186/1471-2334-14-107.

Background: HIV infection reduces the likelihood that individuals with pulmonary tuberculosis are smear positive and that they have cavitatory disease. Antiretroviral therapy (ART) may shift the pattern of disease to be more similar to that of HIV negative patients. This would aid diagnosis - which often depends on sputum smears - but would also increase infectiousness. We assessed the effect of HIV and ART on smear positivity and cavitatory disease in laboratory-confirmed pulmonary TB patients.

Methods: Three sputum samples were collected per pulmonary TB suspect and were examined using microscopy and culture. Chest radiographs were available for a subset of patients as part of another study. The effect of HIV and ART status on sputum smear positivity and lung cavitation were evaluated using multivariable logistic regression.

Results: Of 1 024 laboratory-confirmed pulmonary TB patients who were identified between January 2005 and December 2011, 766 had HIV and ART status available. Positive sputum smears were significantly more common among HIV negative individuals than HIV positive individuals (adjusted OR = 2.91, 95% CI 1.53 - 5.55). Compared to those HIV positive but not on ART, patients on ART were more likely to be smear positive (adjusted OR = 2.33, 95% CI 1.01 - 5.39) if they had been on ART ≤ 6 months, but only slightly more likely to be smear positive (adjusted OR = 1.43, 95% CI 0.68 - 2.99) if they were on ART > 6 months. HIV negative patients were more likely than HIV positive patients to have cavitatory disease (adjusted OR = 1.97, 95% CI 1.20 - 3.23). Patients on ART > 6 months had a slight increase in cavitatory disease compared to HIV positive patients not on ART (adjusted OR = 1.68, CI 0.78 - 3.63).

Conclusion: HIV infection is associated with less smear positivity and cavitation in pulmonary TB patients. Among HIV positive patients, the use of ART shifts the presentation of disease towards that seen in HIV-negative individuals, which facilitates diagnosis but which also could increase infectiousness.

Abstract Full-text [free] access

Editor’s notes: Attenuation of immune responses to Mycobacterium tuberculosis reduces pulmonary immunopathology in patients with HIV co-infection. This decreases the risk of pulmonary cavitation and of testing sputum smear positive on microscopy. Having confirmed these associations, this study further demonstrated that antiretroviral therapy (ART) reverses this association. ART was associated with increased risk of pulmonary cavitation and sputum smear-positivity, likely reflecting restoration of immunopathology. TB cases developing during ART may therefore be more infectious, which has important implications for TB transmission risk.

Avoid TB deaths
Africa
Malawi
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Children on antiretroviral therapy in sub-Saharan Africa should continue co-trimoxazole prophylaxis long-term

A randomized trial of prolonged co-trimoxazole in HIV-infected children in Africa.

Bwakura-Dangarembizi M, Kendall L, Bakeera-Kitaka S, Nahirya-Ntege P, Keishanyu R, Nathoo K, Spyer MJ, Kekitiinwa A, Lutaakome J, Mhute T, Kasirye P, Munderi P, Musiime V, Gibb DM, Walker AS, Prendergast AJ; Antiretroviral Research for Watoto (ARROW) Trial Team. N Engl J Med 2014 Jan 2;370(1):41-53. doi: 10.1056/NEJMoa1214901.

Background: Co-trimoxazole (fixed-dose trimethoprim-sulfamethoxazole) prophylaxis administered before antiretroviral therapy (ART) reduces morbidity in children infected with the human immunodeficiency virus (HIV). We investigated whether children and adolescents receiving long-term ART in sub-Saharan Africa could discontinue co-trimoxazole.

Methods: We conducted a randomized, noninferiority trial of stopping versus continuing daily open-label co-trimoxazole in children and adolescents in Uganda and Zimbabwe. Eligible participants were older than 3 years of age, had been receiving ART for more than 96 weeks, were using insecticide-treated bed nets (in malaria-endemic areas), and had not had Pneumocystis jirovecii pneumonia. Coprimary end points were hospitalization or death and adverse events of grade 3 or 4.

Results: A total of 758 participants were randomly assigned to stop or continue co-trimoxazole (382 and 376 participants, respectively), after receiving ART for a median of 2.1 years (interquartile range, 1.8 to 2.3). The median age was 7.9 years (interquartile range, 4.6 to 11.1), and the median CD4 T-cell percentage was 33% (interquartile range, 26 to 39). Participants who stopped co-trimoxazole had higher rates of hospitalization or death than those who continued (72 participants [19%] vs. 48 [13%]; hazard ratio, 1.64; 95% confidence interval [CI], 1.14 to 2.37; P = 0.007; noninferiority not shown). There was no evidence of variation across ages (P=0.93 for interaction). A total of 2 participants in the prophylaxis-stopped group (1%) died, as did 3 in the prophylaxis-continued group (1%). Most hospitalizations in the prophylaxis-stopped group were for malaria (49 events, vs. 21 in the prophylaxis-continued group) or infections other than malaria (53 vs. 25), particularly pneumonia, sepsis, and meningitis. Rates of adverse events of grade 3 or 4 were similar in the two groups (hazard ratio, 1.20; 95% CI, 0.83 to 1.72; P=0.33), but more grade 4 adverse events occurred in the prophylaxis-stopped group (hazard ratio, 2.04; 95% CI, 0.99 to 4.22; P=0.05), with anemia accounting for the largest number of events (12, vs. 2 with continued prophylaxis).

Conclusions: Continuing co-trimoxazole prophylaxis after 96 weeks of ART was beneficial, as compared with stopping prophylaxis, with fewer hospitalizations for both malaria and infection not related to malaria.

Abstract   Full-text [free] access

Editor’s notes: Co-trimoxazole prophylaxis is known to reduce morbidity and mortality in patients with low CD4 count. However, once patients have been established on antiretroviral therapy (ART) it has not been known whether this prophylaxis should be continued or stopped. This key randomised controlled trial, conducted in Uganda and Zimbabwe, amongst children (median age 7.9 years) on ART for more than 96 weeks, provides strong evidence that in this setting, co-trimoxazole prophylaxis should be continued long-term. Children who stopped co-trimoxazole prophylaxis had higher rates of hospitalisation and death, with the majority of hospitalisations due to malaria, pneumonia, sepsis or meningitis. The benefits of co-trimoxazole prophylaxis were seen in all age groups, in patients with high CD4 counts, in malaria endemic (Uganda) and non-endemic (Zimbabwe) areas, and despite high background rates of co-trimoxazole resistance. WHO needs to reconsider its current recommendation that co-trimoxazole prophylaxis can be stopped in children >5 years of age who have adequate immune reconstitution on ART (CD4 >350 cells/mm3).

Avoid TB deaths
Africa
Uganda, Zimbabwe
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Response to measles vaccination in children on antiretroviral therapy

Changes in measles serostatus among HIV-infected Zambian children initiating antiretroviral therapy before and after the 2010 measles outbreak and supplemental immunization activities.

Rainwater-Lovett K, Nkamba HC, Mubiana-Mbewe M, Bolton-Moore C, Moss WJ. J Infect Dis. 2013 Dec 1;208(11):1747-55. doi: 10.1093/infdis/jit404. Epub 2013 Aug 2.

Background: In 2010, Zambia had a large measles outbreak, providing an opportunity to measure changes in measles serostatus following highly active antiretroviral therapy (HAART), exposure to measles virus, and revaccination among children infected with human immunodeficiency virus (HIV).

Methods: A prospective cohort study of 169 HIV-infected Zambian children aged 9-60 months with a history of measles vaccination was conducted to characterize the effects of HAART and revaccination on measles immunoglobulin G (IgG) serostatus by enzyme immunoassay.

Results: Prior to the measles outbreak, only 23% of HIV-infected children were measles IgG seropositive at HAART initiation. After adjusting for 6-month changes in baseline age and 5% changes in nadir CD4+ T-cell percentage, HAART was not associated with measles IgG seroconversion. However, 18 of 19 children seroconverted after revaccination. Eight children seroconverted during the outbreak without revaccination and were likely exposed to wild-type measles virus, but none were reported to have had clinical measles.

Conclusions: Immune reconstitution after HAART initiation did not restore protective levels of measles IgG antibodies, but almost all children developed protective antibody levels after revaccination. Some previously vaccinated HIV-infected children had serological evidence of exposure to wild-type measles virus without a reported history of measles.

Abstract access 

Editor’s notes: Successful immunisation campaigns in Africa resulted in >90% decline in measles cases by 2008. However, maintenance of high levels of population immunity and surveillance are vital to prevent outbreaks. HIV-positive children have lower response rates to measles vaccination and a poorer qualitative response to the vaccine compared to HIV-negative children. This study showed that less than 50% of vaccinated HIV-positive children had protective antibody levels. Immune reconstitution after starting antiretroviral therapy (ART) did not have any effect to restore protective antibody levels to measles virus. But, revaccination did result in most children seroconverting (i.e. developing protective measles antibodies).

With the scale up of ART, HIV-associated mortality has declined substantially. However, immune reconstitution does not restore protection against these infections. Further, the increased survival due to ART also results in an accumulation of HIV-positive children susceptible to diseases such as measles. The findings of this study would support revaccination of HIV-positive children not only for individual protection but also for measles elimination.

Avoid TB deaths
Africa
Zambia
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Limited linkage to care following mobile screening for HIV, TB and non-communicable diseases

Linkage to HIV, TB and Non-Communicable Disease Care from a Mobile Testing Unit in Cape Town, South Africa.

Govindasamy D, Kranzer K, van Schaik N, Noubary F, Wood R, Walensky RP, Freedberg KA, Bassett IV, Bekker LG. PLoS One. 2013 Nov 13;8(11):e80017. doi: 10.1371/journal.pone.0080017.

Background: HIV counseling and testing may serve as an entry point for non-communicable disease screening.

Objectives: To determine the yield of newly-diagnosed HIV, tuberculosis (TB) symptoms, diabetes and hypertension, and to assess CD4 count testing, linkage to care as well as correlates of linkage and barriers to care from a mobile testing unit.

Methods: A mobile unit provided screening for HIV, TB symptoms, diabetes and hypertension in Cape Town, South Africa between March 2010 and September 2011. The yield of newly-diagnosed cases of these conditions was measured and clients were followed-up between January and November 2011 to assess linkage. Linkage to care was defined as accessing care within one, three or six months post-HIV diagnosis (dependent on CD4 count) and one month post-diagnosis for other conditions. Clinical and socio-demographic correlates of linkage to care were evaluated using Poisson regression and barriers to care were determined.

Results: Of 9 806 clients screened, the yield of new diagnoses was: HIV (5.5%), TB suspects (10.1%), diabetes (0.8%) and hypertension (58.1%). Linkage to care for HIV-infected clients, TB suspects, diabetics and hypertensives was: 51.3%, 56.7%, 74.1% and 50.0%. Only disclosure of HIV-positive status to family members or partners (RR=2.6, 95% CI: 1.04-6.3, p=0.04) was independently associated with linkage to HIV care. The main barrier to care reported by all groups was lack of time to access a clinic.

Conclusion: Screening for HIV, TB symptoms and hypertension at mobile units in South Africa has a high yield but inadequate linkage. After-hours and weekend clinics may overcome a major barrier to accessing care.

Abstract  Full-text [free] access

Editor’s notes: This study reported that a mobile testing unit in South African township could simultaneously identify a high yield of new HIV diagnoses as well as patients with TB symptoms, diabetes and hypertension. However, linkage to care was inadequate and limited by difficulties accessing clinic services.

Avoid TB deaths
Africa
South Africa
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