A. Willem Sturm

Extensively drug-resistant tuberculosis as a cause of death in patients co-infected with tuberculosis and HIV in a rural area of South Africa

BACKGROUND The epidemics of HIV-1 and tuberculosis in South Africa are closely related. High mortality rates in co-infected patients have improved with antiretroviral therapy, but drug-resistant tuberculosis has emerged as a major cause of death. We assessed the prevalence and consequences of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis in a rural area in KwaZulu Natal, South Africa. METHODS We undertook enhanced surveillance for drug-resistant tuberculosis with sputum culture and drug susceptibility testing in patients with known or suspected tuberculosis. Genotyping was done for isolates resistant to first-line and second-line drugs. RESULTS From January, 2005, to March, 2006, sputum was obtained from 1539 patients. We detected MDR tuberculosis in 221 patients, of whom 53 had XDR tuberculosis. Prevalence among 475 patients with culture-confirmed tuberculosis was 39% (185 patients) for MDR and 6% (30) for XDR tuberculosis. Only 55% (26 of 47) of patients with XDR tuberculosis had never been previously treated for tuberculosis; 67% (28 of 42) had a recent hospital admission. All 44 patients with XDR tuberculosis who were tested for HIV were co-infected. 52 of 53 patients with XDR tuberculosis died, with median survival of 16 days from time of diagnosis (IQR 6-37) among the 42 patients with confirmed dates of death. Genotyping of isolates showed that 39 of 46 (85%, 95% CI 74-95) patients with XDR tuberculosis had similar strains. CONCLUSIONS MDR tuberculosis is more prevalent than previously realised in this setting. XDR tuberculosis has been transmitted to HIV co-infected patients and is associated with high mortality. These observations warrant urgent intervention and threaten the success of treatment programmes for tuberculosis and HIV.

Effect of age, polymicrobial disease, and maternal HIV status on treatment response and cause of severe pneumonia in South African children: a prospective descriptive study

BACKGROUND HIV-related pneumonia is the main cause of paediatric hospital admissions in southern Africa. We aimed to measure predictors of treatment failure and the cause of non-responsive pneumonia in children admitted to hospital with severe pneumonia in Durban, South Africa. METHODS We investigated 358 children aged 1-59 months who presented with WHO-defined severe or very severe pneumonia. Children were recruited irrespective of HIV status and started on a standard antimicrobial regimen of benzylpenicillin and gentamicin. All infants also received high-dose trimethoprim-sulfamethoxazole. The primary outcome measure was treatment failure at 48 h. FINDINGS 242 (68%) children were HIV infected, 41 (12%) HIV exposed, uninfected, and 75 (21%) HIV uninfected. Failure to respond by 48 h was predicted by age under 1 year (adjusted odds ratio 6.38, 95% CI 2.72-14.91, p<0.0001), very severe disease (2.47, 1.17-5.24, p=0.0181), HIV status (HIV infected 10.3, 3.26-32.51; HIV exposed, uninfected 6.02, 1.55-23.38; p=0.0003), and polymicrobial disease (one organism 2.06, 1.05-4.05; two organisms 10.75, 4.38-26.36; p<0.0001) on logistic regression analysis. All children with three organisms failed treatment. 72/110 treatment failures had at least two organisms isolated. Three of nine HIV-exposed, uninfected infants, 29/74 HIV-infected, but no HIV-uninfected infants who failed study therapy had Pneumocystis jirovecii pneumonia. INTERPRETATION For children younger than 1 year, the WHO guidelines are inadequate and need to be revised since both HIV-infected and HIV-exposed, uninfected infants had more treatment failures than did HIV-uninfected infants. Polymicrobial disease is an important reason for treatment failure, and we need to identify rapid low-cost diagnostic methods to assist clinicians.

Trichomonas vaginalis Is Associated with Pelvic Inflammatory Disease in Women Infected with Human Immunodeficiency Virus

We assessed the association between the causative agents of vaginal discharge and pelvic inflammatory disease (PID) among women attending a rural sexually transmitted disease clinic in South Africa; the role played by coinfection with human immunodeficiency virus type 1 (HIV-1) was studied. Vaginal and cervical specimens were obtained to detect Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, and bacterial vaginosis. HIV-1 infection was established by use of serum antibody tests. A total of 696 women with vaginal discharge were recruited, 119 of whom had clinical PID. Patients with trichomoniasis had a significantly higher risk of PID than did women without trichomoniasis (P=.03). PID was not associated with any of the other pathogens. When the patients were stratified according to HIV-1 status, the risk of PID in HIV-1-infected patients with T. vaginalis increased significantly (P=.002); no association was found in patients without HIV-1. T. vaginalis infection of the lower genital tract is associated with a clinical diagnosis of PID in HIV-1-infected women.

Evolution of the Extensively Drug-Resistant F15/LAM4/KZN Strain of Mycobacterium tuberculosis in KwaZulu-Natal, South Africa

BACKGROUND Although several hot spots of multidrug-resistant tuberculosis have been identified on the African continent, extensive drug resistance (XDR) has not been reported until recently, when a large number of XDR cases were identified in KwaZulu-Natal. The majority of the patients involved were infected with the same strain of Mycobacterium tuberculosis (F15/LAM4/KZN). We report this strains development from multidrug resistance to XDR. METHODS We searched databases for studies performed during the period 1994-2005 that involved the resistance patterns of isolates of M. tuberculosis with the F15/LAM4/KZN strain fingerprint. RESULTS As early as 1994, the F15/LAM4/KZN strain was responsible for a number of cases of multidrug-resistant tuberculosis, indicating the ability of the strain to cause cases of primary resistant tuberculosis. Some of the isolates were also resistant to streptomycin. From 1994 onwards, multidrug-resistant isolates with resistance to additional drugs were found, and the first XDR isolate was discovered in 2001. CONCLUSIONS Drug resistance to as many as 7 drugs developed in a local strain of M. tuberculosis in slightly more than a decade. This coincided with the introduction of the directly observed therapy-based and directly observed therapy-plus-based tuberculosis-control programs. It is postulated that the introduction of these programs in the absence of susceptibility testing or drug resistance surveillance has been instrumental in the development of XDR in this highly transmissible F15/LAM4/KZN strain. The expanding pool of human immunodeficiency virus-infected, tuberculosis-susceptible individuals has likely contributed to this development.

Genome Analysis of Multi- and Extensively-Drug-Resistant Tuberculosis from KwaZulu-Natal, South Africa

The KZN strain family of Mycobacterium tuberculosis is a highly virulent strain endemic to the KwaZulu-Natal region of South Africa, which has recently experienced an outbreak of extensively-drug resistant tuberculosis. To investigate the causes and evolution of drug-resistance, we determined the DNA sequences of several clinical isolates - one drug-susceptible, one multi-drug resistant, and nine extensively drug-resistant - using whole-genome sequencing. Analysis of polymorphisms among the strains is consistent with the drug-susceptibility profiles, in that well-known mutations are observed that are correlated with resistance to isoniazid, rifampicin, kanamycin, ofloxacin, ethambutol, and pyrazinamide. However, the mutations responsible for rifampicin resistance in rpoB and pyrazinamide in pncA are in different nucleotide positions in the multi-drug-resistant and extensively drug-resistant strains, clearly showing that they acquired these mutations independently, and that the XDR strain could not have evolved directly from the MDR strain (though it could have arisen from another similar MDR strain). Sequencing of eight additional XDR strains from other areas of KwaZulu-Natal shows that they have identical drug resistant mutations to the first one sequenced, including the same polymorphisms at sites associated with drug resistance, supporting the theory that this represents a case of clonal expansion.

Interrelationships among human immunodeficiency virus type 1 infection, bacterial vaginosis, trichomoniasis, and the presence of yeasts.

Vaginal discharge of mixed etiology occurs frequently, with abnormal vaginal flora being the most common condition. The interrelationships among the disturbance of the vaginal ecology, the presence of yeasts, and infection with Trichomonas vaginalis and human immunodeficiency virus type 1 (HIV-1) were investigated among women presenting to a sexually transmitted diseases service. Analysis was done for 598 women. Although the prevalence of HIV-1 infection increased linearly with increasing Nugents score (bacterial vaginosis score of Gram stain), the prevalence of T. vaginalis increased suddenly, from 12% in patients with a Nugents score of < or =3 to 33% in patients with a score of 4, and remained at this level at higher scores. Yeast colonization and vulvovaginal candidiasis were inversely related to Nugents scores. T. vaginalis might be responsible for the change in normal vaginal flora and may, therefore, be one of the causes of bacterial vaginosis. This could lead to more effective HIV-1 acquisition.

Symptomatic vaginal discharge is a poor predictor of sexually transmitted infections and genital tract inflammation in high-risk women in South Africa

BACKGROUND Diagnosis and treatment of sexually transmitted infections (STIs) is a public health priority, particularly in regions where the incidence of human immunodeficiency virus (HIV) infection is high. In most developing countries, STIs are managed syndromically. We assessed the adequacy of syndromic diagnosis of STIs, compared with laboratory diagnosis of STIs, and evaluated the association between STI diagnosis and the risk of HIV acquisition in a cohort of high-risk women. METHODS HIV-uninfected high-risk women (n = 242) were followed for 24 months. Symptoms of STIs were recorded, and laboratory diagnosis of common STI pathogens was conducted every 6 months. Forty-two cytokines were measured by Luminex in cervicovaginal lavage specimens at enrollment. Human immunodeficiency virus type 1 (HIV-1) infection was evaluated monthly. RESULTS Only 12.3% of women (25 of 204) who had a laboratory-diagnosed, discharge-causing STI had clinically evident discharge. Vaginal discharge was thus a poor predictor of laboratory-diagnosed STIs (sensitivity, 12.3%; specificity, 93.8%). Cervicovaginal cytokine concentrations did not differ between women with asymptomatic STIs and those with symptomatic STIs and were elevated in women with asymptomatic STIs, compared with women with no STIs or bacterial vaginosis. Although laboratory-diagnosed STIs were associated with increased risk of HIV infection (hazard ratio, 3.3 [95% confidence interval, 1.5-7.2)], clinical symptoms were not. CONCLUSIONS Syndromic STI diagnosis dependent on vaginal discharge was poorly predictive of laboratory-diagnosed STI. Laboratory-diagnosed STIs were associated with increased susceptibility to HIV acquisition, while vaginal discharge was not.

Molecular epidemiology and transmission dynamics of Mycobacterium tuberculosis in rural Africa

The relative contribution of reactivated and recently acquired tuberculosis to the disease burden in developing countries is unknown, as are the settings within which most transmission occurs. In an attempt to answer these questions, we combined molecular techniques (restriction fragment length polymorphism analysis) and conventional epidemiology (risk factor analysis and contact tracing) to study 246 consecutive cases of smear‐positive tuberculosis in rural South Africa. We estimate that 29–43% of the cases were recently acquired, as they were clustered. We were unable to identify firm transmission links between 73% of clustered cases. Our findings suggest that most smear‐positive tuberculosis in rural Africa is both recently acquired and casually transmitted. Tuberculosis control may therefore depend more on promoting early presentation, rapid diagnosis and vaccine development than on chemotherapy.

Nosocomial Transmission of Extensively Drug-Resistant Tuberculosis in a Rural Hospital in South Africa

BACKGROUND Extensively drug-resistant tuberculosis (XDR-tuberculosis) is a global public health threat, but few data exist elucidating factors driving this epidemic. The initial XDR-tuberculosis report from South Africa suggested transmission is an important factor, but detailed epidemiologic and molecular analyses were not available for further characterization. METHODS We performed a retrospective, observational study among XDR-tuberculosis patients to identify hospital-associated epidemiologic links. We used spoligotyping, IS6110-based restriction fragment-length polymorphism analysis, and sequencing of resistance-determining regions to identify clusters. Social network analysis was used to construct transmission networks among genotypically clustered patients. RESULTS Among 148 XDR-tuberculosis patients, 98% were infected with human immunodeficiency virus (HIV), and 59% had smear-positive tuberculosis. Nearly all (93%) were hospitalized while infectious with XDR-tuberculosis (median duration, 15 days; interquartile range: 10-25 days). Genotyping identified a predominant cluster comprising 96% of isolates. Epidemiologic links were identified for 82% of patients; social network analysis demonstrated multiple generations of transmission across a highly interconnected network. CONCLUSIONS The XDR-tuberculosis epidemic in Tugela Ferry, South Africa, has been highly clonal. However, the epidemic is not the result of a point-source outbreak; rather, a high degree of interconnectedness allowed multiple generations of nosocomial transmission. Similar to the outbreaks of multidrug-resistant tuberculosis in the 1990s, poor infection control, delayed diagnosis, and a high HIV prevalence facilitated transmission. Important lessons from those outbreaks must be applied to stem further expansion of this epidemic.

Lack of Association between the Nasopharyngeal Carriage of Streptococcus pneumoniae and Staphylococcus aureus in HIV-1–Infected South African Children

We investigated the nasopharyngeal carriage of Streptococcus pneumoniae and Staphylococcus aureus in 355 children hospitalized with severe pneumonia. Of the children, 239 (67.3%) were human immunodeficiency virus (HIV)-1 positive; 169 (47.6%) carried S. pneumoniae, 91 (25.6%) carried S. aureus, and 33 (9.3%) carried both. S. pneumoniae carriage was not related to HIV-1 status. The HIV-1-positive children had a significantly higher rate of S. aureus carriage than did the HIV-1-negative children (31.4% vs. 13.8%; P<.001). The rate of S. aureus carriage in the HIV-1-negative S. pneumoniae carriers was significantly lower than that in the noncarriers (5.5% vs. 21.3%; P=.013), but the rate of S. aureus carriage in the HIV-1-positive S. pneumoniae carriers was not significantly lower than that in the noncarriers (26.3% vs. 36.0%; P=.11). We did not find a negative association between S. pneumoniae and S. aureus carriage in HIV-1-positive hospitalized children with severe pneumonia.