Diagnosis and management of community-acquired pneumonia in children: South African Thoracic Society guidelines

BACKGROUND

Pneumonia remains a major cause of morbidity and mortality amongst South African children. More comprehensive immunisation regimens, strengthening of HIV programmes, improvement in socioeconomic conditions and new preventive strategies have impacted on the epidemiology of pneumonia. Furthermore, sensitive diagnostic tests and better sampling methods in young children improve aetiological diagnosis.

OBJECTIVES

To produce revised guidelines for pneumonia in South African children under 5 years of age.

METHODS

The Paediatric Assembly of the South African Thoracic Society and the National Institute for Communicable Diseases established seven expert subgroups to revise existing South African guidelines focusing on: (i) epidemiology; (ii) aetiology; (iii) diagnosis; (iv) antibiotic management and supportive therapy; (v) management in intensive care; (vi) prevention; and (vii) considerations in HIV-infected or HIVexposed, uninfected (HEU) children. Each subgroup reviewed the published evidence in their area; in the absence of evidence, expert opinion was accepted. Evidence was graded using the British Thoracic Society (BTS) grading system. Sections were synthesized into an overall guideline which underwent peer review and revision.

RECOMMENDATIONS

Recommendations include a diagnostic approach, investigations, management and preventive strategies. Specific recommendations for HIV infected and HEU children are provided.

VALIDATION

The guideline is based on available published evidence supplemented by the consensus opinion of SA paediatric experts. Recommendations are consistent with those in published international guidelines.

National service for adolescents and adults with severe obsessive–compulsive and body dysmorphic disorders

Aims and Method

National guidelines for the assessment and treatment of obsessive–compulsive disorder (OCD) and body dysmorphic disorder were published in 2005 by the National Institute for Health and Clinical Excellence (NICE). Local services are unable to treat a small but significant number of the most severely ill patients successfully, and the guidelines recommend that such patients should have access to highly specialised care. From 1 April 2007, the Department of Health decided to centrally fund treatment services for severe, chronic, refractory OCD and BDD. We describe a new National Service for Refractory OCD; its rationale, treatments offered, referral criteria and expected clinical outcomes.

Results

Initial results from one centre show an average 42% reduction in OCD symptoms at the end of treatment.

Clinical Implications

The operational challenges and potential generalisability of this model of healthcare delivery are discussed. We present a summary of the progress made so far in establishing a new, coherent National Service for Refractory OCD, 18 months after the NICE guideline was published. the aim of the paper is to educate clinicians about the service and describe its rationale, treatments offered, referral criteria and expected clinical outcomes.

Community model in treating obsessive–compulsive and body dysmorphic disorders

Aims and Method

In November 2005, the National Institute for Health and Clinical Excellence published guidelines for the treatment of obsessive–compulsive disorder (OCD) and body dysmorphic disorder. These guidelines incorporated a stepped care approach with different interventions advised throughout the patient pathway. South West London and St George's Mental Health NHS Trust devised a system of expert clinicians with special expertise in OCD/body dysmorphic disorder to help deliver this model of care. To aid the delivery of service it was decided to operationalise the definitions of severity of OCD/body dysmorphic disorder at each of the stepped-care levels. Examples are given as to how this has been applied in practice. Outcome is presented in terms of clinical hours in the first year of operation.

Results

In total, 108 patients were referred to the service in the first year. Many of these patients were treated by offering advice and support and joint working with the community mental health team and psychotherapy in primary care teams who had referred. Sixty-eight patients were treated by a member of the specialist service alone and 57 of these suffered from severe OCD. Outcome data from these 57 patients is presented using an intention-to-treat paradigm. They showed a clinically and statistically significant reduction in OCD symptoms after 24 weeks of cognitive–behavioural therapy comprising graded exposure and self-imposed response prevention. the mean Yale–Brown Obsessive Compulsive Scale score dropped from 28 (severe OCD) to 19 (considerable OCD). Depressive symptoms on the Beck Depression Inventory also decreased by an average 24% over the same period.

Clinical Implications

The feasibility of extending this model of service organisation to other areas and other diagnoses is discussed.

Molecular typing of Treponema pallidum strains from patients with neurosyphilis in Pretoria, South Africa

OBJECTIVE

To evaluate the molecular typing system for Treponema pallidum using cerebrospinal fluid (CSF) specimens obtained from patients with neurosyphilis in Pretoria, South Africa.

METHODS

CSF specimens were collected from 32 men and 18 women with suspected late neurosyphilis. Typing of T pallidum involved PCR amplification and restriction analysis of the tprE, G and J genes and determination of the number of 60 base pair tandem repeats within the arp gene by PCR amplification.

RESULTS

Of 13 typeable specimens, 4 strain types were identified: 2i, 3e, 14a and 17e. Subtype 14a was identified in 7 specimens (53.8%), subtype 3e in 4 specimens (30.7%) and subtypes 17e and 2i in 1 specimen (7.6%) each.

CONCLUSIONS

This study shows that the typing system can be applied to specimens which may contain low numbers of spirochaetes such as CSF.

Comparison of a TaqMan-based real-time polymerase chain reaction with conventional tests for the detection of Trichomonas vaginalis

OBJECTIVE

To compare a TaqMan-based real-time polymerase chain reaction (PCR) with conventional PCR, culture, and wet-mount microscopy for the diagnosis of trichomoniasis in women.

METHODS

Vaginal swabs from 119 women were tested for Trichomonas vaginalis by wet mount and culture. Paired vaginal lavage and urine specimens were tested by conventional and real-time PCR.

RESULTS

Using an expanded "gold standard", defined as a positive culture result using vaginal swabs and/or a positive PCR test using TVK3/7 primers, the overall prevalence of T vaginalis in the study population was 65.5% (78/119). The detection rate of T vaginalis was 65.5% (78/119) and 36.9% (44/119) by conventional PCR using vaginal washings and urine specimens, respectively; 68.9% (82/119) by real-time PCR using vaginal washings and 61.3% (73/119) by real-time PCR using urine specimens. The sensitivities of conventional PCR using vaginal washings and urine and real-time PCR using vaginal washings and urine, compared with the gold standard were 100%, 56.4%, 100% and 76.7%, and the specificities of these tests were 100%, 97.6%, 82.9% and 97%, respectively.

CONCLUSIONS

The real-time PCR test proved to be significantly more sensitive than culture and wet-mount microscopy, although its specificity was slightly lower than these tests. In addition, it was more sensitive, rapid and less time consuming than conventional PCR for the detection of T vaginalis.

An analysis of fishing vessel accidents

In this paper, accident data collected from the Marine Accident Investigation Branch are presented and an analysis is carried out to determine the most common causes of accidents on fishing vessels. Discussions on fishing vessel-safety assessment and data problems are given.

Evaluation of Xenostrip-Tv, a rapid diagnostic test for Trichomonas vaginalis infection

An immunochromatographic strip test, Xenostrip-Tv, was compared to wet mount and PCR for the diagnosis of Trichomonas vaginalis infection in women. Of 428 specimens tested, 54 (12.6%) were positive by an "expanded gold standard," defined as either a positive wet mount and PCR test with primers TVK3 and TVK7 and/or a positive PCR test confirmed by a second PCR assay with primers TVA5-1 and TVA6; 26 (6%) were positive by wet mount, and 36 (8.4%) were positive by Xenostrip-Tv test. Since the Xenostrip-Tv test is rapid and easy to perform and proved to be more sensitive than wet mount, it should be considered as an alternative to wet mount for point-of-care diagnosis of trichomoniasis, especially in settings where microscopy is impractical.

Use of advances in technology for maritime risk assessment

The maritime industry is moving toward a "goal-setting" risk-based regime. This opens the way to safety engineers to explore and exploit flexible and advanced risk modeling and decision-making approaches in the design and operation processes. In this article, following a brief review of the current status of maritime risk assessment, a design/operation selection framework and a design/operation optimization framework are outlined. A general discussion of control engineering techniques and their application to risk modeling and decision making is given. Four novel risk modeling and decision-making approaches are then outlined with illustrative examples to demonstrate their use. Such approaches may be used as alternatives to facilitate risk modeling and decision making in situations where conventional techniques cannot be appropriately applied. Finally, recommendations on further exploitation of advances in general engineering and technology are suggested with respect to risk modeling and decision making.

Molecular typing of Treponema pallidum in South Africa: cross-sectional studies

We evaluated a molecular subtyping system for Treponema pallidum for its ability to differentiate between strains obtained from male patients with primary syphilis in South Africa. Of 201 T. pallidum-positive specimens, 161 were typeable, revealing 35 subtypes. The unique subtypes identified in Durban, Cape Town, and Carletonville and the total number of subtypes suggested that the strain population was very diverse and varied geographically.

Amplification of the DNA polymerase I gene of Treponema pallidum from whole blood of persons with syphilis

Previous reports suggest that Treponema pallidum bacteremia occurs in persons with syphilis exposure ('incubating syphilis') and in persons with primary or secondary syphilis. During a recent syphilis outbreak, whole blood samples from 32 persons with suspected syphilis or syphilis exposure were screened using polymerase chain reaction (PCR) to amplify the DNA polymerase I gene (polA) of T. pallidum. Of the 32 samples, polA was amplified from 13 (41%). Of these 13, three were determined to have incubating syphilis; two had primary or secondary syphilis and eight had latent syphilis. This study demonstrates that spirochetemia can occur throughout the course of T. pallidum infection.

Molecular subtyping of Treponema pallidum in an Arizona County with increasing syphilis morbidity: use of specimens from ulcers and blood

A molecular-based subtyping system for Treponema pallidum was used during an investigation of increasing syphilis in Maricopa County, Arizona. Genital ulcer or whole blood specimens from patients with syphilis were assayed by a polymerase chain reaction (PCR) amplification of a T. pallidum DNA polymerase I gene. Positive specimens were typed on the basis of PCR amplification of 2 variable genes. In all, 41 (93%) of 44 of ulcer specimens and 4 (27%) of 15 blood specimens yielded typeable T. pallidum DNA. Twenty-four (53%) of 45 specimens were subtype 14f; other subtypes identified included 4f, 4i, 5f, 12a, 12f, 14a, 14d, 14e, and 14i. Only 2 specimens were from epidemiologically linked patients. This investigation demonstrates that multiple subtypes of T. pallidum can be found in an area with high syphilis morbidity, although 1 subtype (14f) was predominant. Four typeable specimens were from blood, a newly identified specimen source for subtyping.

An outbreak of neonatal infection with Acinetobacter linked to contaminated suction catheters

An outbreak of multi-drug resistant Acinetobacter spp. infection in the neonatal unit at King Edward VIII hospital in Durban, South Africa, is described. Nine out of a total of 218 neonates were infected during the study period. The outbreak was characterized by early onset infection [median postnatal age 3 days (range 1-23 days)] in pre-term babies [median gestational age 33 weeks (range 30-35 weeks)] with an attributable mortality of 22%. The source of the outbreak, determined by ribotyping, was presumed to be contaminated suction bottles and catheters in the neonatal admission room. Five neonates were successfully treated with ciprofloxacin and amikacin. Enforcement of strict infection control practices curtailed the outbreak.

Comparison of culture media for the laboratory diagnosis of chancroid

Seven different agar-based media were compared to determine the optimal set of culture media for primary isolation of Haemophilus ducreyi. Also, a new method for sampling genital ulcers -- with a disposable sterile plastic loop -- and processing specimens that provides a standardised inoculum for culture of H. ducreyi on various media is described. A total of 202 patients with genital ulcer disease was enrolled in this study. A sterile swab or plastic loop was used to sample the base of the ulcers and ulcer material was suspended in sterile phosphate-buffered saline. A 100-microl sample of this suspension was mixed with an equal volume of tryptic soy broth containing IsoVitaleX and centrifuged for 1 min. This suspension was used to inoculate the different media. Plates were incubated at 33 degrees C in micro-aerophilic conditions and examined for growth of H. ducreyi after 48 h. Of the 202 specimens, 77 (38.1%) were culture positive for H. ducreyi. None of the agar bases supported the growth of all H. ducreyi strains. Based on this observation, we recommend the universal use of Mueller-Hinton agar base supplemented with chocolate horse blood and IsovitaleX (MH-HBC) and Columbia agar base supplemented with bovine haemoglobin, activated charcoal, fetal calf serum and IsovitaleX (C-HgCh) to enable comparison of prevalence figures for chancroid. In addition, the novel sampling technique described in this study eliminates sampling bias normally associated with genital ulcer specimens.

Molecular subtyping of Treponema pallidum subspecies pallidum

BACKGROUND AND OBJECTIVES

Epidemiologic studies on syphilis have been hampered by the fact that strains of Treponema pallidum subspecies pallidum (T. pallidum), the causative agent of this disease, cannot be differentiated by either protein-based or deoxyribonucleic acid-based methods. Syphilis is endemic in many developing countries and is common in some industrialized nations. In addition, the disease has been shown to increase the risk of infection with the human immunodeficiency virus.

GOAL

To develop a molecular subtyping method for T. pallidum.

STUDY DESIGN

Two genes exhibiting intrastrain variability were identified as potential targets for strain differentiation: the acidic repeat protein (arp) gene, which contains a variable number of 60 base pair repeats, and a member of the treponema pallidum repeat (tpr) gene family. Polymerase chain reaction amplification and restriction endonuclease digestion of polymerase chain reaction products from laboratory strains and clinical specimens were used to develop a molecular subtyping scheme for T. pallidum.

RESULTS

Determining the number of repeats in the arp gene by polymerase chain reaction resulted in 12 different subtypes among the 63 isolates that were studied. Among those, most (54.2%) had arp genes with 14 repeats. The other 11 subtypes had arp genes with 7 to 21 repeats, each accounting for 2% to 14% of the isolates. Polymerase chain reaction amplification of a member of the tpr gene family from a subset of 46 isolates followed by digestion of the polymerase chain reaction product with MseI resulted in seven restriction fragment length polymorphism patterns designated a to g. Strains with 14 repeats could be grouped into five restriction fragment length polymorphism subtypes. By combining the two systems we observed 16 subtypes among 46 isolates examined. This typing system is stable, reproducible, and easy to perform. In addition, the use of the ABI Genetic Analyzer for the determination of fragment size and banding patterns makes the results unbiased.

CONCLUSION

This is the first molecular subtyping system that distinguishes among clinical isolates of T. pallidum.

Nosocomial transmission of Shigella dysenteriae type 1

An outbreak of dysentery due to Shigella dysenteriae type 1 occurred in a chronic care psychiatric institution in Durban, South Africa. Of the 10 patients who developed dysentery, 4 (40%) died. S. dysenteriae type 1 was isolated from stool samples from two of the four patients tested and ribotyping showed that these isolates were identical but differed from other community acquired strains. The isolates were resistant to ampicillin, chloramphenicol, tetracycline and co-trimoxazole. Infection control measures including isolation, cohort nursing and strict hand disinfection resulted in rapid control of the outbreak.

Ribosomal DNA typing of Haemophilus ducreyi strains: proposal for a novel typing scheme

Local strains of Haemophilus ducreyi were characterized by ribosomal DNA fingerprinting in order to develop a typing scheme for this organism. Chromosomal DNAs from 30 strains were extracted, and restriction fragments were separated by agarose gel electrophoresis after cleavage with BglII, HindIII, HindII, and BstEII. Of the 30 local strains studied, nine BglII, eight HindIII, six HindII, and five BstEII ribotype patterns were observed. In order to develop a typing scheme, we correlated the ribotype patterns obtained with each of the four enzymes for each strain. By this scheme, 13 ribotypes designated b to n were defined among the local strains. This study demonstrates that there is a diversity of ribotypes among H. ducreyi strains in our area, which emphasizes that there are many strains responsible for chancroid. This novel typing scheme provides a useful tool for further epidemiological studies of chancroid.

Perceptions and knowledge about AIDS among family planning clinic attenders in Johannesburg

Many studies assessing the impact of national AIDS prevention programmes on knowledge, attitudes and practices have been published world-wide. Most have found that, while general knowledge increased, there was little change in behaviour. A survey of a random sample of 50 women attending a family planning clinic in Johannesburg determined the current knowledge, attitudes and practices of these sexually active women, aged 20-29 years. All selected respondents agreed to participate and a pretested structured questionnaire was completed. Most individuals had in excess of 7 years' schooling (78.0%), were single (58.0%) and domestic workers (28.6%). The majority were aware of AIDS (88.0%), but only 13.7% felt their knowledge was adequate. Fifty-two per cent knew sexual intercourse was a mode of transmission. Many misconceptions existed, 64.0% cited toilet seats, 47.1% sharing of utensils and 70.1% donating blood as routes by which HIV infection could be acquired. Only 47.1% and 34.1%, respectively, knew that the contraceptive pill and intra-uterine contraceptive device did not protect against HIV infection. Eighty-six per cent of the women were sexually active and 8.0% admitted to currently having more than one sexual partner. None used condoms and, generally, feelings regarding condom use were negative. Most (88.6%) believed AIDS patients should be hospitalised, 68.2% said in isolation wards, and 27.3% felt that AIDS patients should not be allowed to stay in the community. The implications of these findings are discussed and certain recommendations are made.