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Biomedical subjects

S Fisher-Hoch

Publications and source records attributed to S Fisher-Hoch.

17 recordsLinked to original sources
PubMed2000

Limited effectiveness of home drinking water purification efforts in Karachi, Pakistan.

OBJECTIVE: In many developing-country urban areas, municipally supplied water is not microbiologically safe. This study evaluated drinking water quality and effect of home water purification efforts in Karachi, Pakistan. METHODS: Members of 300 households, including 100 households who used the Aga Khan University Hospital Laboratory and 200 of their neighbors were interviewed. In 293 consenting households, structured observations were performed and drinking water was analyzed for the presence of coliforms, using the multiple tube fermentation technique. RESULTS: Although 193 of the 293 households (66%) reported using some method to purify their drinking water, including 169 (58%) who boiled their water, only 48 (16%) of the drinking water samples were free of coliforms. Although a combination of boiling and filtering was the most effective method of purification, only 38% of samples that had been boiled and filtered were free of coliforms. CONCLUSIONS: Further refinements and evaluations of home-based efforts to purify and store water are needed.

Developing Countries↗
PubMed2000

Evaluation of blood bank practices in Karachi, Pakistan, and the government's response.

BACKGROUND: National legislation in Pakistan regulating blood banks has been introduced several times, but has never been passed. To support provincial-level efforts to develop legislation we conducted a study to evaluate blood-banking practices in Karachi, Pakistan, to identify areas that could be improved. METHODS: Thirty-seven blood banks were randomly selected from a list of 87 Karachi blood banks. The research team interviewed blood bank personnel, inspected available facilities and equipment, and observed blood collection using structured questionnaires and observation forms. RESULTS: Of the 37 selected facilities, 25 were operational and 24 agreed to participate. Twelve (50%) of the facilities reported regularly utilizing paid blood donors, while only six (25%) activity recruited volunteer donors. During observation only 8% of facilities asked donors about injecting drug use, and none asked donors any questions about high-risk sexual behaviour. While 95% of blood banks had appropriate equipment and reagents to screen for hepatitis B, only 55% could screen for HIV and 23% for hepatitis C. Twenty-nine percent of the facilities were storing blood products outside the WHO recommended temperature limits. IMPLICATIONS: Practices at most Karachi blood banks fell well below WHO standards. Findings from this study were instrumental in developing and passing legislation to regulate blood transfusion throughout Sindh Province, and suggest a method for improving blood transfusion practices in other developing countries.

Blood Banks↗
PubMed2000

Unsafe injections and the transmission of hepatitis B and C in a periurban community in Pakistan.

Following reports of frequent deaths associated with jaundice and chronic liver disease among adults in a periurban community of Karachi, Pakistan, an investigation was conducted to evaluate the relationship between injections and viral hepatitis infections, to identify the reasons why patients received frequent injections, and to observe the injection practices employed in clinics. Two hundred and three adult patients were interviewed as they left each of the 18 area clinics. Practitioners were interviewed and three consecutive injections were observed at each clinic. Eighty-one per cent of patients received an injection on the day of the interview. Of the 135 patients who provided a serum sample, 59 (44%) had antibodies against hepatitis C virus and 26 (19%) had antibodies against hepatitis B virus. Patients who received more injections were more likely to be infected with hepatitis C. If oral and injected medications were equally effective, 44% of patients preferred injected medication. None of the practitioners knew that hepatitis C could be transmitted by injections. Non-sterile syringes and needles that had been used earlier in the day on other patients were used for 94% of the observed injections. Interventions to limit injections to those which are safe and clinically indicated are needed to prevent injection-associated infections in Pakistan and other low-income countries.

Adult↗
PubMed1998

HIV antibody seroprevalence and associated risk factors in sex workers, drug users, and prisoners in Sindh, Pakistan.

OBJECTIVE: To determine prevalence of HIV infection and risk behaviors in commercial sex workers (CSWs), drug users, and prisoners in Sindh, Pakistan. METHODS: A medical clinic was established in a "red-light" district of Karachi. Eighty-one CSWs who registered at the clinic between November 1993 and June 1994 were provided HIV counseling and testing and administered a risk factor questionnaire. Next, 316 male drug users were tested for HIV-1 antibody from April to July 1994. Finally, a voluntary serosurvey of HIV-1 and HIV-2 and risk behaviors of 3525 prisoners in Sindh was conducted between July 1994 and December 1994. Abbott Recombinant HIV third-generation enzyme-linked immunosorbent assay (ELISA) and confirmatory testing with Western blot analysis were used in all three groups. RESULTS: None of 81 CSWs tested for HIV-1 antibody were positive. None of 316 drug users tested positive for HIV-1 antibody. Of 3441 male prisoners, 1 was HIV-1 infected, and of 84 female prisoners, 1 was HIV-1 infected. No prisoner was positive for HIV-2 antibody. DISCUSSION: The prevalence of HIV in CSWs, drug users, and prisoners in Sindh is low at present. Intervention programs implemented at this stage can make an impact in HIV prevention.

Adolescent↗
PubMed1998

Outbreak of Crimean-Congo haemorrhagic fever in Quetta, Pakistan: contact tracing and risk assessment.

In December 1994 in a private hospital in Quetta, Pakistan, 3 health-workers contracted Crimean-Congo haemorrhagic fever (CCHF) after surgery on a bleeding patient who later died. We conducted a retrospective study to determine transmission risks among contacts. Fifty contacts gave blood for antibody tests and answered questions about exposure. Two of four people exposed percutaneously and one of five with cutaneous exposure contracted CCHE The person with cutaneous exposure was a surgeon who tore his glove during surgery and noted blood on his hand but no cut. There were no anti-CCHF antibodies or CCHF cases among persons whose skin came into contact with body fluids other than blood (0/4), who had skin-to-skin contact (0/16) with patients or were physically close to them (0/21). Three index case relatives reported that although 10 family members had cutaneous exposure, none developed CCHF. The family refused blood tests. CCHF transmission in resource-constrained settings can be limited by focusing on avoiding health worker contact with blood.

Disease Outbreaks↗
PubMed1997

The relationship between therapeutic injections and high prevalence of hepatitis C infection in Hafizabad, Pakistan.

To determine the prevalence and routes of transmission of hepatitis C virus (HCV) infection in Hafizabad, Pakistan, we collected sera in 1993 from a geographically based random sample of residents, and in 1994 identified 15 HCV-infected individuals (cases) and 67 age and sex matched uninfected individuals (controls). Initially we approached 504 households, and collected serum from a randomly selected household member in 309 (64%). Twenty persons (6.5%) had anti-HCV antibody; 31% percent had hepatitis B core antibodies, and 4.3% had hepatitis B surface antigen. In the case-control study, persons who received more therapeutic injections (categorized as averaging 1, 2-4, 5-9 or > 10 injections per year in the previous 10 years) were more likely to be infected with HCV (odds ratio 0, 1.5, 2.5 and 6.9 respectively, P = 0.008) compared to persons averaging 0 injections per year. Efforts to limit therapeutic injections to only those that are medically indicated and that use sterile equipment are essential in order to prevent transmission of HCV.

Adolescent↗
PubMed1995

Treatment options for vulvovaginal candidiasis, 1993.

Vulvovaginal candidiasis (VVC), the second most common form of vaginitis, particularly affects women of childbearing age. Since the 1970s, several new agents have become available for the treatment of VVC. This review focuses on options for the treatment of this condition, critically evaluating the relevant published studies. For the treatment of acute episodes of VVC in nonpregnant women, several topical and oral antifungal agents are clinically and mycologically effective. Topical agents should be considered the first line of therapy; however, oral agents are sometimes associated with better compliance among patients. For acute episodes in pregnant women, a topical agent is the treatment of choice. Until data become available on the treatment of VVC in women infected with human immunodeficiency virus (HIV), the same approach as that used for women without HIV infection should be considered as previously written. For recurrent VVC, the optimal maintenance therapy has not yet been established; however, administration of low-dose oral ketoconazole (100 mg/d) has proven effective. Well-designed studies of the best therapy for VVC in women with HIV infection and for recurrent VVC are urgently needed.

Acute Disease↗
PubMed1992

Serum antibodies to structural proteins of Hantavirus arise at different times after infection.

An enzyme-linked immunosorbent assay (ELISA) was developed for the quantification of serum antibodies against group-specific epitopes of the glycoproteins (G1, G2) and nucleoprotein (NP) of the genus Hantavirus. This assay was used to study the kinetics of the development of serum antibodies after natural infection with Puumala-like virus in humans. To this end a panel of 34 serum samples collected from individuals at different times after natural infection was tested by the ELISA. The samples were also tested for specific IgM and IgG levels against Puumala-like virus, which provided confirmatory data about the presumed timing of infection. It was shown that serum antibodies against the G1 epitope were present in the acute and early convalescent period just before antibodies to the NP epitope could be demonstrated. In contrast, antibodies to two G2 epitopes were present not earlier than in the convalescent and late convalescent period. Since all these categories of antibodies seem to persist for long periods, antibodies against the G1 epitope and the NP epitope may be of specific diagnostic value. Furthermore, levels of G1-specific antibodies and antibodies to either NP or G2 may allow estimation of the time elapsed following initial infection.

Antibodies, Viral↗
PubMed1991

Virus zoonoses and their potential for contamination of cell cultures.

Silent virus infections of laboratory animals present a human health hazard, from direct exposure and from contamination of biological products for human use. Here we report two recent examples. In 1989, an outbreak of lymphocytic choriomeningitis virus (LCMV) infections was recognized among workers at a cancer research center after an animal caretaker developed viral meningitis. Investigation revealed that multiple tumor cell lines at the facility were infected with LCMV, as were research animals injected with these cell lines. Of 82 workers tested, eight (10%) were found to have been infected. The infected workers were more likely than other animal handlers to report handling athymic (nude) mice (p less than .0.007). The number of nude mice used in this facilty had increased five-fold in the previous year, possibly explaining the timing of the outbreak. This is the first reported LCMV outbreak since 1975, and the first to implicate nude mice as a source of human LCMV infections. In November 1989 and January 1990, infections caused by two distinct Ebola-like filoviruses were discovered in non-human primates at quarantine facilities in Virginia and Pennsylvania. Although 22 persons were considered to have high- or medium-risk exposures for Ebola infection, no Ebola-compatible illnesses occurred. One of the medium-risk persons had Ebola IgG antibodies confirmed by IFA and Western blot. Rigorous use of barrier precautions may have limited exposure and infection with these filoviruses. In February 1990, new groups of filovirus-infected monkeys were identified in Virginia and in Texas. Seroconversion occurred in four animal handlers, including one to very high titer, but again no illness was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Hematologic dysfunction in Lassa fever.

Lassa fever is widespread in West Africa, where the case fatality is about 16% in hospitalized adult patients. The clinical course is highly variable, with a few patients developing severe disease with bleeding, adult respiratory distress syndrome, encephalopathy and hypovolemic shock. We studied 70 patients admitted with suspected Lassa fever to a hospital in Sierra Leone, West Africa. Fourteen patients classified as having severe Lassa fever on the basis of serum aspartate amino transferase (AST) greater than 150 IU/L or viremia of greater than 10(3.6) tissue culture infective dose (TCID) 50/ml were found to have statistically significantly depressed lymphocyte counts when compared with patients with mild Lassa fever (AST less than 150 IU/L or viremia, less than 10(3.6)TCID50/ml), (P less than 0.0001) and with febrile control patients, in whom Lassa infection had been excluded by laboratory criteria (P less than 0.0008). Maximum depression occurred a mean of 10.9 days post onset. Patients with severe Lassa fever also had moderate thrombocytopenia, which was statistically significant when compared with febrile control patients (P less than 0.0003) and this occurred a mean of 10.8 days postonset. The most significant changes were in platelet function, which was markedly depressed in patients with severe Lassa fever (P less than 0.0035 in response to ADP and P = 0.0081 for collagen) when compared with patients with mild Lassa fever, and when compared with febrile controls, (P = 0.0013 for ADP and P less than 0.00001 for collagen). This abnormality was usually maximal on admission to hospital, and probably is an early event, preceding hospitalization in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1984

Antibody against viruses in maternal and cord sera: non-specific inhibitors are found to higher titre on the maternal side of the circulation.

Pregnancies were identified in which maternal IgG antibodies against rubella virus were not detectable by single radial haemolysis. Twenty paired maternal/cord sera were then tested for haemagglutination-inhibiting (HI) activity against rubella virus without kaolin pretreatment of the sera. In the absence of specific antibody, the HI activity observed could thus be ascribed to the effect of non-specific inhibitors. The HI activity in maternal sera was significantly (P less than 0.001) higher than that in cord sera. The 20 pairs of sera were similarly tested against a bunyavirus, an alphavirus and a flavivirus, both with and without kaolin pretreatment. The results showed non-specific inhibitors were found to higher titre in maternal sera, with the difference being statistically significant (P less than 0.001) for each of the three viruses.

Absorption↗
PubMed1982

Radial haemolysis for the detection of rubella antibody in acute postnatal rubella.

One hundred and forty-eight sera from 101 cases of acute postnatal rubella were examined by the radial haemolysis (RH) technique currently recommended by the Public Health Laboratory Service of the United Kingdom. In 75 cases the date of onset of rash was known. No sera were RH positive until the third day after the onset of rash and one serum was still negative at 9 days. By 10 days all sera gave a zone of at least 10 mm. The antibody response detected by RH appears later than that detected by haemagglutination inhibition (HI). Thirty-nine of the 101 cases could be diagnosed by seroconversion or a significant rise in titre using the HI test (diagnosis of the remainder depending upon rubella-specific IgM tests). Using the RH test this figure rises to 48 but in ten of these cases reliance on RH would have meant a delay in diagnosis. The results also indicate that many more sera would need to be tested for rubella-specific IgM if the RH test was used instead of the HI test for evaluating possible cases and contacts of rubella.

Acute Disease↗
PubMed1980

Legionnaires' disease in a transplant unit: isolation of the causative agent from shower baths.

Legionnaires' disease was diagnosed in two patients in a transplant unit, both patients having occupied the same postoperative cubicle shortly before onset of their illnesses. Legionella pneumophila was found in water taken from the cubicle shower bath and from other showers in the unit. To eradicate the legionellae, the water supply was treated with chlorine, but this had only a temporary effect.

Adult↗
PubMed1979

Identification of a clinical isolate as Legionella pneumophila by gas chromatography and mass spectrometry of cellular fatty acids.

Culture of a bronchial aspirate from an immunosuppressed patient with severe pneumonia yielded a growth of filamentous poorly staining gram-negative rods. Fluorescence with Legionella pneumophila direct fluorescein-isothiocyanate conjugate was equivocal. Gas-liquid chromatography (GLC) and GLC/mass-spectrometry (GLC-MS) of the cellular fatty acids of the isolate confirmed that the organism was L. pneumophila. GLC and GLC-MS constitute a rapid and definitive method for identification of L. pneumophila isolates.

Bacteria↗