Coverage and yield of entry and follow-up screening for tuberculosis among new immigrants.

The aim of the present study was to determine the effectiveness of entry screening for tuberculosis and biannual follow-up screening among new immigrants in The Netherlands. To achieve this, the present authors analysed screening, prevalence and incidence data of 68,122 immigrants, who were followed for 29 months. Patients diagnosed within 5 months and 6-29 months after entry screening were considered to be detected at entry and during the follow-up period, respectively. Coverage of the second to fifth screening rounds was 59, 46, 36 and 34%, respectively. Yield of entry screening was 119 per 100,000 individuals, and prevalence at entry was 131 per 100,000. Average yield of follow-up screening was highest among immigrants with abnormalities on chest radiography (CXR) at entry (902 per 100,000 individuals). When excluding these, yield of follow-up screening was 9, 37 and 97 per 100,000 screenings for immigrants from countries with tuberculosis incidences of <100, 100-200 and >200 per 100,000, respectively. The incidence during follow-up in individuals with a normal CXR was 11, 58 and 145 per 100,000 person-yrs follow-up in these groups. The proportion of cases detected through screening declined per screening round from 91 to 31%. Yield of entry screening was high. Overall coverage and yield of follow-up screening was low. Follow-up screening of immigrants with a normal chest radiograph from countries with an incidence of <200 per 100,000 individuals was therefore discontinued.

Tuberculosis infection in children who are contacts of immigrant tuberculosis patients.

The present study aimed to determine what proportion of children who are in close contact with immigrant tuberculosis (TB) patients are infected with Mycobacterium tuberculosis. For 1.5 yrs, 14 municipal health services in The Netherlands collected data from all non-Dutch TB patients and their contacts. Close contacts aged < 16 yrs received a tuberculin skin test (TST). A positive TST was defined as an induration of > or = 10 mm among nonvaccinated children, and > or = 16 mm among bacille Calmette-Guérin-vaccinated children. In total, 244 patients had 359 close contacts aged < 16 yrs. Nine out of the 359 (2.5%) had TB. A TST test was given to 298 out of the 359 (83%). Of the 115 contacts of 44 extrapulmonary TB patients, three (3%) had a positive TST. Of the 186 contacts of 58 positive pulmonary TB patients, 30 (16%) had a positive TST. Contacts of sputum smear-positive patients significantly more often had a positive TST (25%), compared with the contacts of sputum smear-negative patients (7%). Children born abroad significantly more often had a positive TST (20%) than children born in The Netherlands (5%). In conclusion, the prevalence of active tuberculosis and latent tuberculosis infection among children who are close contacts of immigrant tuberculosis patients is high and warrants an expansion of contact investigation.

Screening for pulmonary tuberculosis among immigrants: estimated effect on severity of disease and duration of infectiousness.

OBJECTIVE: To estimate the effect of tuberculosis screening among recent immigrants on the severity of disease at diagnosis and on the duration of the infectious period. DESIGN: Comparison of pulmonary tuberculosis cases among immigrants detected through screening with those detected passively, using information from the Netherlands Tuberculosis Register. PARTICIPANTS: Immigrants from highly endemic countries diagnosed with culture-positive pulmonary tuberculosis within 30 months after arrival in The Netherlands, 1993 through 1998. OUTCOME MEASURES: Severity of disease (smear-positive disease, hospitalisation, case fatality) and duration of symptomatic period. RESULTS: A total of 882 bacteriologically confirmed tuberculosis patients from highly endemic countries had been in The Netherlands less than 30 months, and were detected through screening (454), or passively (368). Compared with patients detected passively, patients found through screening were less often sputum smear-positive (OR 0.5, 95%CI 0.3-0.8) and less often hospitalised (OR 0.2, 95%CI 0.1-0.2). Those detected through screening had a shorter symptomatic period. Screening is estimated to have reduced the infectious period by approximately 33%. CONCLUSION: The screening programme detected cases earlier, resulting in fewer hospital admissions, shorter duration of symptoms and therefore probably reduced tuberculosis transmission.

[Tuberculosis screening coverage of immigrants: marked attrition in follow-up screenings]. / Dekkingsgraad van tuberculosescreening bij immigranten: sterke afname bij vervolgscreening.

OBJECTIVE: To estimate the coverage of bi-annual follow-up screening for tuberculosis amongst immigrants, excluding asylum seekers. DESIGN: Retrospective cohort study. METHODS: Participation in bi-annual chest X-ray screening during the first 18 months was recorded for immigrants who underwent entry screening in 1996 in the following Dutch municipal health services (MHS's): Zuid-Kennemerland (Haarlem), Flevoland (Lelystad), Midden-Brabant (Tilburg) en West-Friesland (Hoorn). The number of immigrants that had left the country before the subsequent screening was taken into account in the Zuid-Kennemerland MHS data on screening coverage. RESULTS: Of the 2147 immigrants who underwent entry screening in 1996 (48% men and 52% women; 68% aged 15-34 years), 1075 (50%; range: 29-76) returned for the first follow-up screening and 620 (29%; 21-61) returned for the second. In MHS Zuid-Kennemerland, 113 of the 777 immigrants who had a chest X-ray at entry had left the country before the first follow-up screening, and another 89 had left before the second. Of the remaining persons, who were probably still in the Netherlands, 454 (68%; 454/777 = 58%) returned for the first follow-up screening, and 166 (29%; 166/777 = 21%) returned for the second. CONCLUSION: The coverage of screening for tuberculosis in immigrants decreased after the obligatory entry screening, even when corrected for those who left the country.

Tuberculosis screening among immigrants in The Netherlands: what is its contribution to public health?

Understanding the epidemiology of tuberculosis in migrant communities and designing adequate and comprehensive control strategies is a major challenge facing public health authorities in many low-prevalence countries. In The Netherlands, screening immigrants from tuberculosis high prevalence countries has been conducted since 1966. In this paper, we review risk factors for tuberculosis in migrant populations, the public health importance of tuberculosis and the current screening policy in The Netherlands. TB treatment outcome in migrant populations and operational considerations that ought to be taken into account to optimize current screening practices are also reviewed. The article recommends the setting-up of an information system to evaluate the effectiveness of screening immigrants in The Netherlands, and adjustment of screening policies where needed.

Tuberculosis chemotherapy and sputum conversion among HIV-seropositive and HIV-seronegative patients in south-eastern Uganda.

OBJECTIVE: To investigate if there is a difference in response to tuberculosis treatment between HIV seronegative and HIV seropositive patients following two months of intensive phase tuberculosis treatment. DESIGN: Prospective cohort study. SETTING: St. Francis Leprosy Centre, south-east Uganda. SUBJECTS: Four hundred fifty seven patients with never previously treated sputum smear-positive tuberculosis admitted during a two-year period in 1991/1993. INTERVENTION: Intensive phase treatment with streptomycin, isoniazid, rifampicin and pyrazinamide. MAIN OUTCOME MEASURES: Sputum conversion from a positive to a negative smear at eight weeks of treatment. RESULTS: HIV seropositivity prevalence was 28%. Among HIV seronegative patients, conversion to a negative smear status occurred in 76% persons compared to 78% in HIV seropositive patients. This difference was not statistically significant (OR = 0.9; 95% CI, 0.6-1.5). HIV seropositive patients, however, were more likely to die (p = 0.017). A high prevalence of resistance to isoniazid and streptomycin was found. Isoniazid resistance was more likely in HIV seronegative patients with M. tuberculosis strains compared to HIV seropositive persons (p < 0.005). Initial resistance to antituberculosis drugs did not have a significant effect on smear conversion. CONCLUSION: This study demonstrates that HIV-seropositive status is not a principal factor in delaying sputum conversion among patients receiving intensive phase tuberculosis treatment.

PIP: A prospective cohort study was undertaken to investigate the response of HIV-seropositive and -seronegative patients at St. Francis Leprosy Center, southeastern Uganda, to tuberculosis chemotherapy. The study population included 457 patients without a history of prior tuberculosis therapy between 1991 and 1993. The subjects were exposed to an intensive phase therapy of rifampicin, streptomycin, isoniazid, and pyrazinamide. After the treatment, sputum culture and sensitivity tests were conducted. Findings showed that 77% of the patients who never received tuberculosis treatment in the past converted to a negative smear status after the 8-week treatment. There was no significant difference in sputum conversion rates between HIV-seropositive and -seronegative patients. The study also revealed that HIV seropositivity prevalence was 28%. Among HIV-seronegative patients, conversion to a negative smear status occurred in 76% compared to 78% HIV-seropositive patients. Moreover, a significant number of HIV-seronegative patients died during the initial course of the therapy. Also, a high prevalence of isoniazid and streptomycin resistance was noted; however, this result never affected the conversions of smears. In conclusion, the study clearly demonstrates that other factors outside the seropositive status may be the principal causes of the delay in sputum conversion among patients receiving intensive tuberculosis chemotherapy.

Malaria anticircumsporozoite antibodies in Dutch soldiers returning from sub-Saharan Africa.

One hundred and twenty-five Dutch servicemen returning from central Africa after a short deployment were enrolled in a study aimed at assessing the effectiveness of malaria prevention measures. None of the persons developed an episode of clinically overt malaria during or after deployment, and no antibodies against blood stages of Plasmodium falciparum could be found. However, antibodies against the circumsporozoite protein (CS) of P. falciparum were demonstrable in 14 persons (11.2% of the study population) by an ELISA test using the recombinant CS-antigen R32tet32, while one person only was positive in an IFA test based on schizonts of P. fieldi as antigen. We concluded that the anti-CS-positive servicemen were probably bitten by mosquitoes carrying P. falciparum parasites while the IFA-positive person was possibly infected by P. vivax, P. ovale or P. malariae parasites. There was no significant association between the different antimalaria preventive measures and the development of anti-CS antibodies. Therefore mefloquine prophylaxis as the single most widely used preventive measure in this group of servicemen was possibly a major contributing factor in averting development of overt malaria.

Investigation into typical and atypical tuberculin sensitivity in the Royal Netherlands Army, resulting in a more rational indication for isoniazid prophylaxis.

SETTING: The Department of Military Health Services (DMGZ) vaccination clinic, Utrecht, The Netherlands. OBJECTIVES: To improve upon PPD skin testing procedure by introducing a double Mantoux test. DESIGN: During the first part of the study, from 1986-1988, army recruits were double-tested simultaneously with PPD and Mycobacterium scrofulacaeum sensitin. During the second part of the study, from 1989 to 1993, recruits reacting to PPD, with an induration in the range of 10-15 mm, underwent a second skin test with M. scrofulaceum sensitin. The total study population consisted of 237,692 non-BCG-vaccinated recruits. RESULTS: From 1986-1993 and average of 0.45% persons reacted with indurations > or = 10 mm to PPD. An average of 7.76% if army recruits reacted with indurations > or = 10 mm to M. scrofulaceum sensitin during the first part of the study. Using a modified ITSC (International Tuberculosis Surveillance Centre) model, 48% of the persons reacting to PPD with indurations in the range 10 mm and 15 mm were classified as false-positive. A total of 16% with indurations > or = 10 mm to PPD were classified as false positive. False-positive persons were then excluded from INH chemoprophlaxis. CONCLUSIONS: In areas with a high prevalence of non-tuberculous mycobacteria infection the use of double skin testing might be useful in differentiating between indurations due to tubercle bacilli and those due to infection with non-tuberculous mycobacteria.

Diarrhea morbidity among Dutch military service men in Goma, Zaire.

An outbreak of diarrheal disease occurring among service men of the Royal Netherlands Forces while serving in the refugee camps in Goma, Zaire, is presented. Post-travel questionnaires were given to 131 military service men returning from Goma. In addition, routine blood investigations were undertaken and stool examined for persons with abdominal complaints. A high prevalence (59%) of diarrheal disease associated with the eating of food served by a local hotel was noted. Fifty percent of persons who developed diarrhea in this period had symptoms persisting for up to 10 days. Pathogens were recovered from the stools of five persons, and four of these had Shigella organisms isolated. The outbreak of diarrhea among the service men was directly linked to the eating of food that was prepared by a local Goma hotel, the possible causative agent for this outbreak being Shigella organisms. Both military and civilian humanitarians working in areas such as refugee camps with a high prevalence of diarrheal diseases should carefully consider eating from local restaurants and hotels.

Leprosy and infection with the human immunodeficiency virus in Uganda; a case-control study.

Both leprosy and infection with the human immunodeficiency virus (HIV) are endemic in Uganda. Various speculations about a possible interaction between the two infections have been put forward but not confirmed. A case-control study involving 189 new leprosy patients and 481 matched controls, resident in eight Ugandan districts, was carried out to investigate if any relationship exists between leprosy and infection with HIV-1 in Uganda. Serum samples from 23 (12.2%) of the 189 leprosy patients tested positive for HIV-1 antibodies as compared to 88 (18.3%) of the 481 control sera. The two proportions of HIV seropositivity are not different statistically. A stratified analysis of the data by districts was done and showed a negative relationship between leprosy and HIV infection in the case of Rakai District (0.04 < odds ratio < 0.61, p = 0.002). It is recommended that studies seeking to observe the clinical progress of dually infected patients might help to reveal new knowledge about a possible relationship between HIV and leprosy and about the immunology of leprosy in general.

Type 1 reactions in leprosy, neuritis and steroid therapy: the impact of the human immunodeficiency virus.

The incidence of type 1 reactions and neuritis among HIV seronegative and HIV seropositive leprosy patients was investigated. HIV seropositivity was associated with an increased incidence of type 1 reactions among multibacillary (MB) patients, which were observed in 9 of 12 seropositive MB patients and in 8 of 40 HIV seronegative MB patients (P < 0.0005). Similarly, the incidence of neuritis was significantly increased among the HIV seropositive MB patients, of whom 8 developed acute neuritis compared to 3 of the HIV seronegative patients (P < 0.0005). There was no significant difference between the numbers of paucibacillary HIV seropositive and HIV seronegative patients who developed these complications. Both the HIV seronegative and HIV seropositive patients showed a similar response to steroid therapy for the management of acute neuritis.

Hospital-based epidemiological study of reactions, Buluba Hospital, 1985-89.

A retrospective study of 256 reactional episodes, both reversal reaction and erythema nodosum leprosum (ENL), seen in Buluba Hospital over a 5-year period (1985-89) was made. Over 90% of these episodes were due to reversal reaction, with ENL being encountered infrequently. About 80% of reversal reactions occurred during chemotherapy but all the episodes of ENL occurred during this period. Over 70% of both reversal and ENL episodes presented with clinically apparent nerve and skin involvement. The need to assess the effect of multidrug therapy on the incidence of reactions and to develop more sensitive diagnostic tools to detect early neuritis is emphasized. It is also necessary to study those patients who develop recurrent reactional episodes.

Human immunodeficiency virus and leprosy--type 1 reactions, nerve damage and steroid therapy: 'a case report'.

In this study a 28-year-old female with both BL leprosy and HIV infections is discussed. Her clinical progress was followed until she completed MDT. During this period she developed recurrent reactional episodes, nerve damage and intercurrent illnesses--some of which might have been due to steroids.

Hospital-based study on neonatal tetanus, Buluba Hospital, 1985-1989.

Neonatal tetanus is a major cause of morbidity and mortality among neonates in Uganda. A retrospective study has been made of 228 cases of neonatal tetanus seen in Buluba Hospital over the 5-year period of 1985-1989. The number of cases of neonatal tetanus admitted per year to the hospital did not decrease significantly during that period suggesting that the immunization programme aimed at immunization of pregnant women with tetanus toxoid has not had a clear impact. Over 40% of neonatal tetanus cases came from the two nearest subcounties: Waina and Imanyiro. Over 75% of admitted cases of neonatal tetanus accounted for 23% of all deaths among child admissions. More than 90% of neonatal tetanus cases showed the first symptoms of the illness within the first 14 days of life; the shortest incubation period was 2 days. The average age at onset was 5.6 days and the average age at death was 9.9 days. The need for a more effective immunization programme and more intensified activities to increase the proportion of deliveries attended by trained personnel and improve hygienic conditions during and after deliveries is emphasized.

Hospital-based study on neonatal tetanus; Buluba Hospital; 1985-1989

Neonatal tetanus is a major cause of morbidity and mortality among neonates in Uganda. A retrospective study has been made of 228 cases of neonatal tetanus seen in Buluba Hospital over the 5-year period of 1985-1989. The number of cases of neonatal tetanus admitted per year to the hospital did not decrease significantly during that period suggesting that the immunization programme aimed at immunization of pregnant women with tetanus toxoid has not had a clear impact. Over 40pc of neonatal tetanus cases came from the two nearest subcounties: Waina and Imanyiro. Over 75pc of admitted cases of neonatal tetanus accounted for 23pc of all deaths among child admissions. More than 90pc of neonatal tetanus cases showed the first symptoms of the illness within the first 14 days of life; the shortest incubation period was 2 days. The average age at onset was 5.6 days and the average age at death was 9.9 days. The need for a more effective immunization programme and more intensified activities to increase the proportion of deliveries attended by trained personnel and improve hygienic conditions during and after deliveries is emphasized