First report of Q fever in Oman.

Although serologic evidence suggests the presence of Q fever in humans and animals in Saudi Arabia and the United Arab Emirates, acute Q fever has not been reported on the Arabian Peninsula. We report the first two cases of acute Q fever in Oman

Laboratory Diagnosis of Viral Hepatitis C : The Sultan Qaboos University Hospital experience

Objectives: A retrospective study was carried out to assess the performance of hepatitis C diagnostic assays in our laboratory, and to determine the prevalence of hepatitis C among blood donors at the Sultan Qaboos University Hospital. Methods: From 1991 to 2001, approximately 55,000 serum samples collected from blood donors and patients were submitted to our laboratory for testing. All sera were screened for antibodies to hepatitis C virus (HCV) by three successive generations of the enzyme-linked immunosorbent assay (ELISA). Anti-HCV positive sera were further tested by recombinant immunoblot assay (RIBA). Reverse-transcriptase polymerase chain reaction (RT-PCR) for HCV RNA was carried out on a limited number (241) of ELISA positive samples. Results: Out of 30012 samples from blood donors that were screened for anti-HCV, 272 (0.91%) were positive. Of these, 46.5% were confirmed positive by RIBA. The proportion of patient sera that were confirmed positive varied from 95% among intravenous drug users to 81% in patients with hepatitis to 70% in those with haemoglobinopathies. HCV RNA was detected in 67%, 6%, and 0% of the RIBA positive, indeterminate and negative samples respectively. Conclusions: Based on RIBA, the prevalence of anti-HCV among blood donors in Oman is close to 0.5%. In our experience, RIBA-positivity is predictive of HCV infection in two thirds of subjects, and HCV infection is highly unlikely in those who are RIBA-negative. The experience at SQUH with three types of HCV assays has enabled the laboratory to develop a test algorithm, starting with screening anti-HCV ELISA.

Fluctuating antibody response in a cohort of hepatitis C patients

Objective: This project was designed to longitudinally study persons who had antibodies to hepatitis C virus (HCV) to characterise the serologic course of infection. Methods: The subjects were 149 multitransfused patients (141 with thalassaemia major, 3 with thalassaemia intermedia, and 5 with sickle cell anaemia) who had been regularly followed up for 3 to 7 years. Sequential serum samples obtained semi-annually between January 1994 and January 2001 were tested, prospectively, by second or third generation HCV enzyme-linked immunosorbent assay (ELISA), followed by confirmatory recombinant immunoblot assay (RIBA-2 or RIBA-3). Results: Of the 149 patients, 90 did not seroconvert to HCV, whereas 59 had detectable antibodies. On the basis of RIBA results in these 59 patients, 24 (41%) had persistent high antibody levels to structural and non structural HCV antigens, 11 (19%) had persistent low antibody levels, 17 (29%) showed fluctuating antibody levels, and in 5 patients (8%) there was a total or a partial disappearance of specific antibodies (seroreversion), mainly anti-core antibodies. Two patients (3%) had antibody responses that did not fit into any of these four categories. In patients with fluctuating antibody levels, there were periods ranging from 6 months to 2 years when anti-HCV antibodies could not be detected. Conclusion: This study shows that the antibody response to HCV in patients who receive frequent blood transfusions is very variable. Individuals who exhibit intermittent seropositivity are a challenge to diagnosis.

Vacina contra poliomielite: um novo paradigma Polio vaccines: a new paradigma

OBJETIVO: Analisar as estratégias propostas pela Organização Mundial da Saúde (OMS) para controle da poliomielite. FONTES DE DADOS: Levantamento das publicações sobre poliomielite indexadas no Medline, Lilacs e sites da OMS e Ministério da Saúde de janeiro de 2000 a dezembro de 2006. SÍNTESEDOS DADOS: O reconhecimento da paralisia associada aos vírus vacinais e por vírus circulantes derivados da vacina oral não deixa dúvidas de que, em breve, será necessário interromper o uso da vacina oral para poliomielite. Após os vírus selvagens serem erradicados, a vacina oral para poliomielite deverá ser interrompida, de preferência de forma sincronizada em todos os países. Após a interrupção da vacinação, as populações voltarão a ser suscetíveis à poliomielite, podendo ocorrer surtos da doença por vírus selvagens (escape dos laboratórios de forma acidental ou por bioterrorismo). Nos países que já utilizam a vacina para poliomielite com vírus inativado é pouco provável que haja interrupção da vacinação. Países que atualmente utilizam exclusivamente a vacina oral ficarão na dependência da vigilância epidemiológica e dos estoques de vacina oral para controlar eventuais surtos de pólio. Se a vacina oral para poliomielite for reintroduzida nessas populações, haverá novamente o risco de paralisia associada aos vírus vacinais e por vírus circulantes derivados da vacina oral, que podem se disseminar rapidamente para outras regiões e países vizinhos. CONCLUSÕES: É necessário planejar a introdução da vacina para poliomielite com vírus inativado no calendário de rotina brasileiro, assim como adquirir tecnologia para sua produção, que atualmente é insuficiente para as necessidades globais.<br>OBJECTIVE: Review the World Health Organization (WHO) strategies for poliomyelitis control. DATA SOURCES: Retrieval of publications on poliomyelitis indexed in Medline, Lilacs and in the WHO and Health Ministry sites, from January 2000 to December 2006. DATA SYNTHESIS: Acknowledgement of vaccine-associated paralysis and oral vaccine-derived circulating viruses’ paralysis shall certainly require discontinuation of oral vaccination for poliomyelitis use in a short time. After eradication of the wild viruses, oral vaccination for poliomyelitis should be discontinued, preferably in a synchronized manner in all the countries. After termination of vaccination programs, people will become susceptible again to poliomyelitis virus and disease outbreaks caused by wild viruses may occur (accidental escape from laboratories or bioterrorism). In countries already using inactivated poliovirus vaccine, it is unlikely that vaccination will be interrupted. Countries that currently use exclusively oral poliovirus vaccine will have to rely on epidemiological surveillance and on oral vaccine inventories to control potential polio outbreaks. If the oral poliovirus vaccine is reintroduced in those populations, there will be again a risk for vaccine-associated paralysis and oral vaccine-derived circulating viruses’ that may spread rapidly to other regions and to nearby countries. CONCLUSIONS: Inactivated poliovirus vaccine introduction in the routine Brazilian vaccination calendar should be programmed as well as acquisition of technology for inactivated poliovirus vaccine production since the latter is currently insufficient to cover global demand