Tuberculosis diagnosis and treatment practices of private physicians in Karachi, Pakistan

In a densely populated urban area of Karachi, Pakistan, a questionnaire survey was made of the knowledge and practices of 120 private general practitioners about the diagnosis and treatment of tuberculosis (TB). The majority knew that cough, fever and weight loss were the main symptoms of TB, but less than half knew that blood in sputum, poor appetite and chest pain were associated with the disease. Only 58.3% of physicians used sputum microscopy for diagnosing TB and 35.0% used it as a follow-up test. Only 41.7% treated TB patients themselves, the remaining referring their patients to specialists. Around 73.3% of the doctors were aware of the 4 first-line anti-TB drugs. Efforts to improve the knowledge of private practitioners, and strategies to enhance public-private collaboration forTB control in urban areas are urgently required.

Overnight home oximetry: can it identify patients with obstructive sleep apnea-hypopnea who have minimal daytime sleepiness?

BACKGROUND

Overnight home oximetry is being widely used as a case selection technique for patients with suspected obstructive sleep apnea-hypopnea (OSAH). In the absence of excessive daytime sleepiness (EDS), patients with snoring and/or witnessed apnea are considered to have low probability of OSAH.

METHODS

Patients suspected to have OSAH, who denied EDS, and had a normal overnight home oximetry were studied by polysomnography for presence of significant OSAH (apnea/hypopnea index (AHI) > 15/h).

RESULTS

Twelve (40%) of the 30 patients studied had significant OSAH. All had a 2% oxygen desaturation index of less than 10/h. The sensitivity of oximetry increased at lower desaturation indices butthis was associated with decreased specificity. Review of oximetry waveform pattern, by experienced physicians, did not improve the diagnostic accuracy. Combining oximetry with a clinical prediction rule would have reduced the need for polysomnography by 30%.

CONCLUSION

Many patients, who present with snoring and/or witnessed apnea and are referred to a sleep disorder clinic for suspected OSAH, may have significant OSAH even if they deny EDS. Overnight home oximetry did not help discriminate between those patients with or without OSAH.

Is there a value of mantoux test and erythrocyte sedimentation rate in pre-employment screening of health care workers for tuberculosis in a high prevalence country?

SETTING

Pre-employment screening of health care workers (HCWs) is practiced widely. Research needs to be carried out to evaluate the screening procedure in developing countries.

OBJECTIVE

To evaluate the efficacy of Mantoux test and erythrocyte sedimentation rate (ESR) for the diagnosis of active tuberculosis (TB), in pre-employment screening of HCWs, in a high prevalence country.

DESIGN

Pre-employment screening of all new employees was reviewed from June to September 2000. The screening consisted of history, physical examination, blood and urine tests, Mantoux test and a chest radiograph. Patients with clinical, laboratory or radiological features suggestive of active TB were referred to a specialist.

RESULTS

Out of 207 employees, a Mantoux reaction of > or = 10 mm and ESR of > or = 25 mm/first hour was noted in 90 (43.5%) and 21 (10.1%), respectively. One person had symptoms suggestive of TB and was already on anti-tuberculosis therapy at the time of screening. All other employees were asymptomatic. Based on radiographic findings, four (2%) cases were referred and one was given anti-tuberculosis therapy. An additional 48 (23.1%) employees were referred on the basis of positive Mantoux or elevated ESR; none were found to have active TB.

CONCLUSION

In high prevalence countries use of Mantoux test and ESR in pre-employment screening of HCWs is not recommended for detection of active TB.

A hospital based preliminary report on sleep disordered breathing in Pakistani population

BACKGROUND

Sleep Disordered Breathing is an important medical condition leading to significant morbidity and mortality. Western studies have shown its prevalence in middle age to be 9% in women and 24% in men. The aim of this study was to have a preliminary assessment on the frequency of Sleep Disordered Breathing in Pakistani subjects.

METHOD

Patients attending a medical clinic were surveyed. A sleep questionnaire elicited information about snoring, witnessed apnea, nocturnal choking and excessive daytime sleepiness. Data were recorded for age, height, collar size and weight. Epworth Sleepiness Scale was used to assess excessive daytime sleepiness. Statistical analysis was by chi square test, t-test and Fisher's exact test. A p-value less than 0.05 was considered significant.

RESULTS

A total of 123 subjects (M:F = 2:1) were included in the study. The frequency of snoring was found to be 46%. Snoring with apnoea was reported in 7% and snoring with apnoea and excessive daytime sleepiness in 3%. Snorers were more obese (p < 0.001), older (p < 0.003), with higher body mass index (p < 0.001) and larger collar size (p < 0.006) than non-snorers. Hypertension was more common in patients with sleep disordered breathing (35%) as compared to those without (16%).

CONCLUSIONS

This is the first preliminary data on sleep disordered breathing from Pakistan that reflects that the prevalence is similar to that seen in the West. The risk factors and association with hypertension are also comparable.

Differential SLP-76 expression and TCR-mediated signaling in effector and memory CD4 T cells

We present in this study novel findings on TCR-mediated signaling in naive, effector, and memory CD4 T cells that identify critical biochemical markers to distinguish these subsets. We demonstrate that relative to naive CD4 T cells, memory CD4 T cells exhibit a profound decrease in expression of the linker/adapter molecule SLP-76, while effector T cells express normal to elevated levels of SLP-76. The reduced level of SLP-76 is memory CD4 T cells is coincident with reduced phosphorylation overall, yet the residual SLP-76 couples to a subset of TCR-associated linker molecules, leading to downstream mitogen-activated protein (MAP) kinase activation. By contrast, effector CD4 T cells strongly phosphorylate SLP-76, linker for activation of T cells, and additional Grb2-coupled proteins, exhibit increased associations of SLP-76 to phosphorylated linkers, and hyperphosphorylate downstream Erk1/2 MAP kinases. Our results suggest distinct coupling of signaling intermediates to the TCR in naive, effector, and memory CD4 T cells. Whereas effector CD4 T cells amplify existing TCR signaling events accounting for rapid effector responses, memory T cells engage fewer signaling intermediates to efficiently link TCR triggering directly to downstream MAP kinase activation.

Heterogeneity of the memory CD4 T cell response: persisting effectors and resting memory T cells

Defining the cellular composition of the memory T cell pool has been complicated by an inability to distinguish effector and memory T cells. We present here an activation profile assay, using anti-CD3 and antigenic stimuli, that clearly distinguishes effector and memory CD4 T cells and defines subsets of long-lived memory CD4 T cells based on CD62 ligand (CD62L) expression. The CD62L(low) memory subset functionally resembles effector cells, exhibiting hyper-responsiveness to antigenic and anti-CD3 mediated stimuli, high proliferative capacity, and rapid activation kinetics. The CD62L(high) memory subset functionally resembles resting memory cells, exhibiting hyporesponsiveness to anti-CD3 stimuli, lower proliferative capacity, and slower activation kinetics. Our results indicate that the memory CD4 T cell pool is heterogeneous, consisting of persisting effectors and resting memory T cells.

[Atypical endometrial hyperplasia. Prognosis and course]

The treatment of patients with the diagnosis atypical endometrial hyperplasia has been disputed during the last decades. The aim of the study was to evaluate the treatment of these patients and analyse the progression rate to invasive carcinoma of the endometrium. Fifty-seven patients with atypical hyperplasia were examined and treated from 1976 through 1991. The medical records were examined retrospectively and the pathology slides were revised by one pathologist in accordance with the 1975 WHO recommendations. Thirty-one (54%) patients were on oestrogen treatment as monotherapy at the time of diagnosis. Forty-two patients had a hysterectomy performed within five months, and five patients had a hysterectomy performed 10 to 61 months after diagnosis. A total of 18 out of 57 patients (31.6%) had or developed endometrial carcinoma all with myometrial invasion: 14 stage I with < or = 50% myometrial invasion, three stage I with > 50% myometrial invasion, and one stage IV. There was no significant difference in age, body mass index, parity or hormone replacement treatment between the group with endometrial carcinoma and the group without endometrial carcinoma. We conclude that unopposed oestrogen treatment and nulliparity are the main risk factors for atypical hyperplasia and that hysterectomy is the appropriate treatment for patients with atypical hyperplasia of the endometrium.

Pneumothorax: a review of 146 adult cases admitted at a university teaching hospital in Pakistan

OBJECTIVE

There is a lack of data on the etiology and outcome of pneumothorax among the Pakistani population. Our aim was to review the etiology, clinical course, management and outcome of patients presenting with pneumothorax.

PATIENTS AND METHODS

All adult cases with pneumothorax admitted to a University Teaching Hospital in Karachi, between January 1992 and June 1996, were reviewed and analyzed.

RESULTS

A total of 146 patients were reviewed. Their mean age was 46.3 years (SD +/- 17.8 years) with a male to female ratio of 3.7:1. Secondary pneumothorax was the commonest type seen (45%), followed by traumatic (21%), iatrogenic (18%) and primary (16%). Tuberculosis (47%) and COPD (45%) were most common lung diseases associated with secondary pneumothorax. Pneumothorax secondary to TB presented at an earlier age than that with COPD (49.6 vs. 60.1 years). Similarly, patients with primary pneumothorax were significantly younger than patients with secondary pneumothorax (42.3 vs. 51.7 years). Rib fracture was the most common cause of traumatic pneumothorax. Coronary artery bypass grafting, transthoracic fine needle aspiration and neck vein cannulations were the leading iatrogenic causes. The commonest symptoms of pneumothorax were dyspnea (68%) and chest pain (40%). Most cases (81%) were successfully managed by intercostal tube drainage.

CONCLUSION

In our study population, secondary pneumothorax was the commonest variety seen. TB was the commonest cause of secondary pneumothorax, closely followed by COPD. Nearly 40% of pneumothorax were either traumatic or iatrogenic. Intercostal tube drainage remains the treatment of choice for pneumothorax.

Effector CD4 T Cells Are Biochemically Distinct from the Memory Subset: Evidence for Long-Term Persistence of Effectors In Vivo

Memory T cell responses are believed to be mediated by long-lived memory T cells that arise directly from a subset of short-lived, activated effector T cells that have reverted to the resting state. Although widely accepted, definitive proof that memory T cells arise from effectors is lacking because of the inability to reliably distinguish these subsets based on known phenotypic or functional parameters. We have used a biochemical approach to distinguish effector and memory CD4 T cell subsets and follow the differentiative fate of effector cells in vivo. When examined biochemically, effector and memory CD4 T cells are strikingly distinct and exhibit qualitative and quantitative differences in tyrosine phosphorylation. These effector-specific patterns were identical in effectors derived either from naive CD4 T cells (primary effectors) or memory CD4 T cells (memory effectors). To monitor the fate of effector cells in vivo, Ag-activated CD4+ TCR-transgenic T cells were transferred into irradiated BALB/c mice. These TCR-transgenic CD4 T cells persisted in adoptive hosts for several months, gave a recall response to Ag, yet exhibited effector-specific biochemical profiles. These results suggest that a subset of effector CD4 T cells can persist in vivo and contribute to long-term immunity by mediating secondary immune responses.

Effector CD4 T cells are biochemically distinct from the memory subset: evidence for long-term persistence of effectors in vivo

Memory T cell responses are believed to be mediated by long-lived memory T cells that arise directly from a subset of short-lived, activated effector T cells that have reverted to the resting state. Although widely accepted, definitive proof that memory T cells arise from effectors is lacking because of the inability to reliably distinguish these subsets based on known phenotypic or functional parameters. We have used a biochemical approach to distinguish effector and memory CD4 T cell subsets and follow the differentiative fate of effector cells in vivo. When examined biochemically, effector and memory CD4 T cells are strikingly distinct and exhibit qualitative and quantitative differences in tyrosine phosphorylation. These effector-specific patterns were identical in effectors derived either from naive CD4 T cells (primary effectors) or memory CD4 T cells (memory effectors). To monitor the fate of effector cells in vivo, Ag-activated CD4+ TCR-transgenic T cells were transferred into irradiated BALB/c mice. These TCR-transgenic CD4 T cells persisted in adoptive hosts for several months, gave a recall response to Ag, yet exhibited effector-specific biochemical profiles. These results suggest that a subset of effector CD4 T cells can persist in vivo and contribute to long-term immunity by mediating secondary immune responses.

Prevalence of pulmonary tuberculosis on the roof of the world

SETTING

The Shimshal Valley, a remote village in Northern Pakistan, is one of the seven Pamirs of Central Asia, widely known as the roof of the world.

OBJECTIVE

To investigate the prevalence of pulmonary tuberculosis (TB) in the Shimshal Valley.

DESIGN

The Rapid Village Survey Method (RVS) was used to investigate the prevalence of pulmonary tuberculosis. The selection criteria were chronic cough, hemoptysis, past history of TB and close contact with a tuberculous patient. After clinical examination, a chest radiograph was done and a single spot sputum sample was obtained for smear examination.

RESULTS

The total population of the village was 1077, of whom 231 cases were studied. Overcrowding affected 75% of the study population. The prevalence of smear positive pulmonary TB in the village studied was 554 per 100000 population, and the prevalence of active smear-negative TB was estimated at 1949/100 000. The prevalence of active pulmonary TB increased with age and the only risk factor for active TB was age over 45 years. Of the 21 cases with a past history of pulmonary TB, only 38% had completed a full course of chemotherapy.

CONCLUSION

Pulmonary TB is a very serious health issue in the rural community (Shimshal Valley) of Pakistan. This study highlights the lack of efficacy of national tuberculosis control programs in the country.

Role of fibreoptic bronchoscopy in the management of immunocompromised patients with pulmonary infiltrates

Immunocompromised patients are prone to develop various pulmonary complications. The range of diagnostic possibilities is wide, infection being the commonest cause. Non-invasive diagnostic tests are often unrewarding. In this study, we have evaluated the diagnostic efficacy and safety of fibreoptic bronchoscopy in immunocompromised patients with pulmonary infiltrates. Patients tolerated the procedure well. This technique identified the etiology in up tp 75% of cases. After treatment based on the result of bronchoscopy, 63% patients improved and were discharged.

Attitudes of Asian medical students towards smoking

BACKGROUND

There have been numerous studies on smoking habits among young adults in developed countries. Similar data from developing countries are scanty.

METHODS

A survey of medical students from one of the medical colleges in Pakistan assessed their smoking habits and attitudes towards smoking. In June 1993 a coded survey questionnaire was sent to each medical student at The Aga Khan Medical University in Karachi requesting data on their smoking habits, their attitudes towards smoking in various areas of the hospital, and their views about passive smoking and tobacco publicity.

RESULTS

Of 324 medical students, 89% responded of whom 11% were current smokers. The incidence of smoking was greater among male students than females (17% versus 4%). The average age of initiation of smoking was 17 years and the major influence was friends. There was an increased awareness of harmful effects of smoking among medical students. Almost all felt that passive smoking was injurious to health.

CONCLUSION

The prevalence of current smokers among Asian medical students was found to be 11%. Females smoked less than their male counterparts. There has been an increased awareness of the hazards of passive smoking among the medical students and most were in favour of legislative actions to discourage tobacco advertising.

Hot flushes in men with pituitary adenoma

BACKGROUND

Hot flushes are common in menopausal women and also in men made acutely hypogonadal after orchiectomy or testicular injury. It is, however, an unusual symptom in patients with hypogonadism secondary to pituitary tumors.

METHODS

In evaluating the histories of men with hypogonadal state associated with nonfunctioning pituitary macroadenoma we were struck by the presence of hot flushes in four of them.

RESULTS

All four of the patients were hypogonadal with sexual dysfunction preoperatively. All had low gonadotropins and low testosterone levels with varying degrees of panhypopituitarism. All had successful transsphenoidal removal of tumors. None had endocrine improvement following surgery. All patients had improvement in sexual function and the hot flushes with administration of testosterone postoperatively.

CONCLUSIONS

Hot flushes are an uncommon presentation in men with pituitary adenoma. Perhaps the symptom will become more prominent if it is specifically questioned. We postulate that the cause of the flushing is related to nonsuppressed pulsatile secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus.

Attitudes to smoking and smoking habits among hospital staff

BACKGROUND

Health professionals should take an active role against smoking, so it is relevant to have information on their smoking habits and their attitudes towards smoking, especially with a view to identifying and offering help to those smokers who wish to stop. Staff in Llandough Hospital were surveyed to determine their smoking habits and attitudes, and the findings were compared with those of a similar survey at Llandough in 1987.

METHODS

In October 1991 a questionnaire was sent to each member of staff employed half time or more requesting data on age, sex, department, smoking habit, attitudes to smoking in various areas of the hospital, and attitudes to access to smoking rest rooms for patients, staff, and visitors. Smokers were asked whether they would like to join a "quit smoking" group. Non-responders were sent a reminder four weeks later and all replies returned by 31 December 1991 were analysed.

RESULTS

The response rate was 82%; of the respondents, 65% were non-smokers, 15% ex-smokers, and 20% current smokers. The prevalence of current smokers was 5% among doctors, 20% among nurses, 18% among administrative and clerical staff, and 40-42% among domestics, catering, and portering staff. Thirty eight per cent of responders wished smoking to be completely forbidden in all areas of the hospital and 90% in certain areas such as wards, offices, cafeteria, and laboratories. Nearly half wanted smoking to be allowed in rest rooms and over 60% wanted a 24 hour facility for smoking for staff, 56% for patients, and 44% for visitors. Only 39% of smokers wished to join a "quit smoking" support group. In comparison with the 1987 survey, the response rate in this study was higher (82% v 70%), the proportion of non-smokers had increased (65% v 59%), and more smokers wanted help (39% v 26%). Fewer wanted 24 hour access to smoking areas for staff and for visitors.

CONCLUSION

This hospital should capitalise on these changes of attitude among staff and proceed more rapidly with the implementation of policies to further reduce smoking among staff, visitors, and patients. As a first step a smoking cessation counsellor has been appointed.

Tuberculosis contact tracing: are the British Thoracic Society guidelines still appropriate?

The value of contact tracing in South Glamorgan for the period May 1987 to December 1989 was assessed. Tuberculosis was diagnosed in six (3.5%) of 170 close contacts. All were young and were detected in the initial screening. Tuberculosis was not found among 441 casual contacts. The value of follow up of contacts after the initial screening and of screening casual contacts in districts with a low prevalence of tuberculosis is questioned.

Audit of a tuberculosis contact tracing clinic

OBJECTIVE

To determine the efficiency of tuberculosis contact tracing in South Glamorgan 1987-9.

DESIGN

Review of records of contact tracing clinic and of data from the Mycobacterium Reference Unit. The clinic's practice was compared with 1983 British Thoracic Society's recommendations.

SETTING

Health authority tuberculosis control programme.

MAIN OUTCOME MEASURES

Proportion of contacts screened, follow up attendance rates, number of secondary cases detected, and quality of record keeping.

RESULTS

101 index patients and 611 contacts were identified. 596 (97.5%) contacts were screened, of whom 139 should not have been. Of 356 contacts requiring a Heaf test, 237 were tested, seven refused the test, and 112 had chest radiography without a Heaf test. 95 contacts were unnecessarily tested. 87 contacts had chest radiography unnecessarily and seven should have had radiography but did not. 34 contacts were given follow up appointments inappropriately and seven were overlooked for follow up. Tuberculosis was diagnosed in five asymptomatic contacts, all at initial screening and all close contacts of index patients with pulmonary disease.

CONCLUSION

Inadequacy of data, non-adherence to contact tracing guidelines, and failure to define the term highly infectious index case resulted in many contacts being unnecessarily screened or followed up.

IMPLICATIONS

The efficiency of tracing contacts would be improved by specifying smear results and ethnic origin of the index case on the notification form, clearly classifying contacts as close or causal, and clearly defining the term highly infectious.