salah ibrahim - Academia.edu (original) (raw)

Papers by salah ibrahim

Epidemiology and Infection, 2005

SUMMARYWe conducted a prospective birth cohort study in rural Sudan to assess measles virus (MV)-... more SUMMARYWe conducted a prospective birth cohort study in rural Sudan to assess measles virus (MV)-specific antibody levels at different time points in infancy. Dried blood spots were collected on filter paper at birth (cord blood) and at ages 6, 12 and 24 months (heel-prick). Maternally derived MV-specific antibody levels were high in cord blood samples, but at the age of 6 months had dropped below cut-off values in half of the infants. By extrapolation it was concluded that the current Expanded Programme of Immunization (EPI) target age for measles vaccination of 9 months was an appropriate choice for this area. At the age of 24 months acquired MV-specific antibodies were detected in 65–85% of the cohort, which corresponded well with the 79% of infants reported to be vaccinated by this age. This study demonstrates the usefulness of filter paper blood samples for seroepidemiological studies in developing countries.

Vaccine, 2001

Few epidemiological studies have been undertaken of measles disease among Sudanese, although meas... more Few epidemiological studies have been undertaken of measles disease among Sudanese, although measles is the third leading cause of death since 1995 among childhood diseases that can be prevented by immunization. The measles vaccine was introduced into the EPI program in Mini-review Article

Journal of medical case reports, Jan 4, 2017

The Bacillus Calmette-Guérin vaccine, which is used for the prevention of tuberculosis, is consid... more The Bacillus Calmette-Guérin vaccine, which is used for the prevention of tuberculosis, is considered protective against the severe forms of childhood tuberculosis. However, some serious adverse reactions including osteitis of the long bones can occur. We report a case of an 18-month-old Sudanese girl who presented at the age of 3 months with swelling of her left forearm following Bacillus Calmette-Guérin vaccination administered at birth. Radiological and histological investigations confirmed tuberculous osteitis of the distal radius. She responded very well to antituberculous treatment with complete healing at follow-up visits. To the best of our knowledge this is the first case report of osteitis of the radius following Bacillus Calmette-Guérin vaccination described from Sudan. Bacillus Calmette-Guérin osteitis, although rare, should be considered a possible complication of the Bacillus Calmette-Guérin vaccination, and early diagnosis and treatment are essential.

Tropical Medicine and International Health, 2002

Clinical and epidemiological data were collected from 187 clinically diagnosed measles patients i... more Clinical and epidemiological data were collected from 187 clinically diagnosed measles patients in Haj Yousif area, suburban Khartoum. Laboratory tests confirmed the diagnosis in 141 (75%) of the cases, but demonstrated that in 46 (25%) patients the clinical symptoms were not caused by an acute measles virus (MV) infection. According to their vaccination card, 59% of the laboratory-confirmed measles cases had been vaccinated for measles. Compared with non-measles rash disease cases, confirmed measles cases more often had severe illness (P < 0.0001), were dehydrated (P ¼ 0.01) at presentation and less likely to recover without complications [OR 0.19 (95% CI 0.09, 0.39)]. There was no difference in death rate (P ¼ 0.20). Underweight [weight-forage Z score (WAZ) £)2 SD] was an independent predictor of recovery with complications [OR 0.4 (95% CI 0.2, 0.99)]. Severe measles cases (those who developed diarrhoea, pneumonia, otitis media, encephalitis or haemorrhagic rash) had similar vaccination rates and time intervals since vaccination as uncomplicated measles cases. Although severe measles had lower WAZ-scores (P ¼ 0.004), none of the nutritional parameters studied were predictive of outcome. Mortality was higher in the severe measles group [OR 8.8 (95% CI 1.7, 85.2)]. In 11 of 141 confirmed measles cases serological evidence of a recent infection with another virus was found, most commonly varicella zoster virus and dengue virus; spotted fever and rubella were among the most frequent diagnoses in 17 of 47 cases of the non-measles cases.

Journal of Clinical Microbiology, 2001

As measles control and elimination campaigns progress, laboratory confirmation of clinically diag... more As measles control and elimination campaigns progress, laboratory confirmation of clinically diagnosed measles cases becomes increasingly important. However, in many tropical countries collection and storage of clinical specimens for this purpose are logistically complicated. In this study it is shown that blood samples spotted on filter paper are suitable for the laboratory diagnosis of measles using a combination of reverse transcriptase PCR (RT-PCR) analysis and immunoglobulin M (IgM) detection. First, it was shown that in vitro measles virus (MV)-infected cells diluted in human blood and spotted on filter paper can be detected by RT-PCR. Small amounts of infected cells remained detectable after 25 weeks of storage of the filter paper at room temperature, 4 weeks at 37°C, or 2 weeks at 45°C. Subsequently, this RT-PCR was applied to filter paper blood samples collected from 117 clinically diagnosed measles patients in Sudan in 1997 and 1998. Prior laboratory diagnosis had confirme...

Journal of Medical Virology, 2004

Dried blood spots collected on filter paper are considered potential clinical specimens for measl... more Dried blood spots collected on filter paper are considered potential clinical specimens for measles surveillance because of their ease of collection, storage, and transport. The usefulness of these samples for surveillance of measles was evaluated in a field setting. Blood spots were collected by finger-prick from 316 clinically diagnosed measles patients in suburban Khartoum, mostly within a week after onset of the rash. Samples were collected between October, 2000 and April, 2003, and stored at 48C. Measles virus-specific IgM antibodies were detected in 200 (63%) of the samples using an ''in-house'' IgM capture ELISA. For 201 samples reconstitution and IgM measurement was repeated 1 year after initial testing with essentially the same results, showing the stability of IgM in the filter paper under these conditions. In a limited number of samples (n ¼ 38) measles virus-specific IgM was also tested with a commercial indirect IgM ELISA. Although the results of the two assays correlated well, the ''in-house'' IgM capture ELISA proved slightly more sensitive. Measles virus-specific reverse transcriptase polymerase chain reaction (RT-PCR) amplicons were obtained from 16 of 57 (28%) samples tested. Sequencing of the 3 0 456 nucleotides of the nucleoprotein gene showed the continued endemic circulation of genotype B3 viruses identified previously in this region. Although problems related to limited sample quantities were encountered, the present study confirms the usefulness of dried blood spots for measles surveillance. The results also demonstrate that measles continues to be endemic in the Sudan.

Epidemiology and Infection, 2005

SUMMARYWe conducted a prospective birth cohort study in rural Sudan to assess measles virus (MV)-... more SUMMARYWe conducted a prospective birth cohort study in rural Sudan to assess measles virus (MV)-specific antibody levels at different time points in infancy. Dried blood spots were collected on filter paper at birth (cord blood) and at ages 6, 12 and 24 months (heel-prick). Maternally derived MV-specific antibody levels were high in cord blood samples, but at the age of 6 months had dropped below cut-off values in half of the infants. By extrapolation it was concluded that the current Expanded Programme of Immunization (EPI) target age for measles vaccination of 9 months was an appropriate choice for this area. At the age of 24 months acquired MV-specific antibodies were detected in 65–85% of the cohort, which corresponded well with the 79% of infants reported to be vaccinated by this age. This study demonstrates the usefulness of filter paper blood samples for seroepidemiological studies in developing countries.

Vaccine, 2001

Few epidemiological studies have been undertaken of measles disease among Sudanese, although meas... more Few epidemiological studies have been undertaken of measles disease among Sudanese, although measles is the third leading cause of death since 1995 among childhood diseases that can be prevented by immunization. The measles vaccine was introduced into the EPI program in Mini-review Article

Journal of medical case reports, Jan 4, 2017

The Bacillus Calmette-Guérin vaccine, which is used for the prevention of tuberculosis, is consid... more The Bacillus Calmette-Guérin vaccine, which is used for the prevention of tuberculosis, is considered protective against the severe forms of childhood tuberculosis. However, some serious adverse reactions including osteitis of the long bones can occur. We report a case of an 18-month-old Sudanese girl who presented at the age of 3 months with swelling of her left forearm following Bacillus Calmette-Guérin vaccination administered at birth. Radiological and histological investigations confirmed tuberculous osteitis of the distal radius. She responded very well to antituberculous treatment with complete healing at follow-up visits. To the best of our knowledge this is the first case report of osteitis of the radius following Bacillus Calmette-Guérin vaccination described from Sudan. Bacillus Calmette-Guérin osteitis, although rare, should be considered a possible complication of the Bacillus Calmette-Guérin vaccination, and early diagnosis and treatment are essential.

Tropical Medicine and International Health, 2002

Clinical and epidemiological data were collected from 187 clinically diagnosed measles patients i... more Clinical and epidemiological data were collected from 187 clinically diagnosed measles patients in Haj Yousif area, suburban Khartoum. Laboratory tests confirmed the diagnosis in 141 (75%) of the cases, but demonstrated that in 46 (25%) patients the clinical symptoms were not caused by an acute measles virus (MV) infection. According to their vaccination card, 59% of the laboratory-confirmed measles cases had been vaccinated for measles. Compared with non-measles rash disease cases, confirmed measles cases more often had severe illness (P < 0.0001), were dehydrated (P ¼ 0.01) at presentation and less likely to recover without complications [OR 0.19 (95% CI 0.09, 0.39)]. There was no difference in death rate (P ¼ 0.20). Underweight [weight-forage Z score (WAZ) £)2 SD] was an independent predictor of recovery with complications [OR 0.4 (95% CI 0.2, 0.99)]. Severe measles cases (those who developed diarrhoea, pneumonia, otitis media, encephalitis or haemorrhagic rash) had similar vaccination rates and time intervals since vaccination as uncomplicated measles cases. Although severe measles had lower WAZ-scores (P ¼ 0.004), none of the nutritional parameters studied were predictive of outcome. Mortality was higher in the severe measles group [OR 8.8 (95% CI 1.7, 85.2)]. In 11 of 141 confirmed measles cases serological evidence of a recent infection with another virus was found, most commonly varicella zoster virus and dengue virus; spotted fever and rubella were among the most frequent diagnoses in 17 of 47 cases of the non-measles cases.

Journal of Clinical Microbiology, 2001

As measles control and elimination campaigns progress, laboratory confirmation of clinically diag... more As measles control and elimination campaigns progress, laboratory confirmation of clinically diagnosed measles cases becomes increasingly important. However, in many tropical countries collection and storage of clinical specimens for this purpose are logistically complicated. In this study it is shown that blood samples spotted on filter paper are suitable for the laboratory diagnosis of measles using a combination of reverse transcriptase PCR (RT-PCR) analysis and immunoglobulin M (IgM) detection. First, it was shown that in vitro measles virus (MV)-infected cells diluted in human blood and spotted on filter paper can be detected by RT-PCR. Small amounts of infected cells remained detectable after 25 weeks of storage of the filter paper at room temperature, 4 weeks at 37°C, or 2 weeks at 45°C. Subsequently, this RT-PCR was applied to filter paper blood samples collected from 117 clinically diagnosed measles patients in Sudan in 1997 and 1998. Prior laboratory diagnosis had confirme...

Journal of Medical Virology, 2004

Dried blood spots collected on filter paper are considered potential clinical specimens for measl... more Dried blood spots collected on filter paper are considered potential clinical specimens for measles surveillance because of their ease of collection, storage, and transport. The usefulness of these samples for surveillance of measles was evaluated in a field setting. Blood spots were collected by finger-prick from 316 clinically diagnosed measles patients in suburban Khartoum, mostly within a week after onset of the rash. Samples were collected between October, 2000 and April, 2003, and stored at 48C. Measles virus-specific IgM antibodies were detected in 200 (63%) of the samples using an ''in-house'' IgM capture ELISA. For 201 samples reconstitution and IgM measurement was repeated 1 year after initial testing with essentially the same results, showing the stability of IgM in the filter paper under these conditions. In a limited number of samples (n ¼ 38) measles virus-specific IgM was also tested with a commercial indirect IgM ELISA. Although the results of the two assays correlated well, the ''in-house'' IgM capture ELISA proved slightly more sensitive. Measles virus-specific reverse transcriptase polymerase chain reaction (RT-PCR) amplicons were obtained from 16 of 57 (28%) samples tested. Sequencing of the 3 0 456 nucleotides of the nucleoprotein gene showed the continued endemic circulation of genotype B3 viruses identified previously in this region. Although problems related to limited sample quantities were encountered, the present study confirms the usefulness of dried blood spots for measles surveillance. The results also demonstrate that measles continues to be endemic in the Sudan.