Identifying Health Centers in Honduras Infested with Rhodnius Prolixus Using the Seroprevalence of Chagas Disease in Children Younger than 13 Years.

The objective of this study is to determine if a Chagas disease protocol starting with a serological survey is as reliable at identifying insect-infested areas as one using the gold standard entomological survey. The study found that health center areas infested with Rhodnius prolixus were identified using a threshold seroprevalence of 0.1%. The serological survey took half the time and was 30% less expensive than the entomological survey. Developing countries with limited resources may find this strategy useful in combating Chagas disease. This strategy also identifies seropositive children, which facilitates their treatment

Using HIV-attributable mortality to assess the impact of antiretroviral therapy on adult mortality in rural Tanzania.

BACKGROUND: The Tanzanian national HIV care and treatment programme has provided free antiretroviral therapy (ART) to HIV-positive persons since 2004. ART has been available to participants of the Kisesa open cohort study since 2005, but data to 2007 showed a slow uptake of ART and a modest impact on mortality. Additional data from the 2010 HIV serological survey provide an opportunity to update the estimated impact of ART in this setting. METHODS: The Kisesa Health and Demographic Surveillance Site (HDSS) has collected HIV serological data and demographic data, including verbal autopsy (VA) interviews since 1994. Serological data to the end of 2010 were used to make two estimates of HIV-attributable mortality, the first among HIV positives using the difference in mortality between HIV positives and HIV negatives, and the second in the population using the difference between the observed mortality rate in the whole population and the mortality rate among the HIV negatives. Four time periods (1994-1999, 2000-2004, 2005-2007, and 2008-2010) were used and HIV-attributable mortality estimates were analysed in detail for trends over time. A computer algorithm, InterVA-4, was applied to VA data to estimate the HIV-attributable mortality for the population, and this was compared to the estimates from the serological survey data. RESULTS: Among HIV-positive adults aged 45-59 years, high mortality rates were observed across all time periods in both males and females. In HIV-positive men, the HIV-attributable mortality was 91.6% (95% confidence interval (CI): 84.6%-95.3%) in 2000-2004 and 86.3% (95% CI: 71.1%-93.3%) in 2008-2010, while among women, the HIV-attributable mortality was 87.8% (95% CI: 71.1%-94.3%) in 2000-2004 and 85.8% (95% CI: 59.6%-94.4%) in 2008-2010. In the whole population, using the serological data, the HIV-attributable mortality among men aged 30-44 years decreased from 57.2% (95% CI: 46.9%-65.3%) in 2000-2004 to 36.5% (95% CI: 18.8%-50.1%) in 2008-2010, while among women the corresponding decrease was from 57.3% (95% CI: 49.7%-63.6%) to 38.7% (95% CI: 27.4%-48.2%). The HIV-attributable mortality in the population using estimates from the InterVA model was lower than that from HIV sero-status data in the period prior to ART, but slightly higher once ART became available. DISCUSSION: In the Kisesa HDSS, ART availability corresponds with a decline in adult overall mortality, although not as large as expected. Using InterVA to estimate HIV-attributable mortality showed smaller changes in HIV-related mortality following ART availability than the serological results

Serological survey of anti-group A rotavirus IgM in UK adults

Rotaviral associated disease of infants in the UK is seasonal and infection in adults not uncommon but the relationship between these has been little explored. Adult sera collected monthly for one year from routine hospital samples were screened for the presence of anti-group A rotavirus immunoglobulin M class antibodies as a marker of recent infection. Anti-rotavirus IgM was seen in all age groups throughout the year with little obvious seasonal variation in the distribution of antibody levels. IgM concentrations and the proportion seropositive above a threshold both increased with age with high concentrations consistently observed in the elderly. Results suggest either high infection rates of rotavirus in adults, irrespective of seasonal disease incidence in infants, IgM persistence or IgM cross-reactivity. These results support recent evidence of differences between infant and adult rotavirus epidemiology and highlight the need for more extensive surveys to investigate age and time related infection and transmission of rotavirus

Serological Survey Of Salmonella gallinarum Antibody In Chickens Around Jos, Plateau State, Nigeria

A serological survey of the prevalence of antibodies to Salmonella gallinarum among chickens under two different management systems around Jos, Plateau State, Nigeria was carried out using the standard plate agglutination test. The objective of this study was to determine serologically the prevalence of antibodies against Salmonella gallinarum among apparently healthy chickens around Jos. A total of 700 serum samples made up of 450 exotic and 250 local breed of chickens were used for this study with 37.9% seropositvity. In the free range system (19.3%) of the flocks sampled were seropositive for Salmonella gallinarium antibodies while in the semi intensive, 18.6% of the flock tested positive. The serum agglutination test (SAT) was adapted to the microtitre format used to determine somatic and flagella titres. The antigen used for this study was specific for S. gallinarum, hence differentiation between species infection was assessed in this study. Perhaps the most feasible way to eradicate the disease is to encourage farmers (both small and large scale) to break the disease cycle at their levels by embarking on prompt and regular vaccination programmes. It is thus concluded that Salmonella gallinarum (fowl typhoid) is present in the area investigated. Fowl typhoid may continue to have a negative effect on the economy of poultry production in Nigeria if not controlled. A statistical analysis was precluded due to inadequate data sets

Estimating infectious disease parameters from data on social contacts and serological status

In dynamic models of infectious disease transmission, typically various mixing patterns are imposed on the so-called Who-Acquires-Infection-From-Whom matrix (WAIFW). These imposed mixing patterns are based on prior knowledge of age-related social mixing behavior rather than observations. Alternatively, one can assume that transmission rates for infections transmitted predominantly through non-sexual social contacts, are proportional to rates of conversational contact which can be estimated from a contact survey. In general, however, contacts reported in social contact surveys are proxies of those events by which transmission may occur and there may exist age-specific characteristics related to susceptibility and infectiousness which are not captured by the contact rates. Therefore, in this paper, transmission is modeled as the product of two age-specific variables: the age-specific contact rate and an age-specific proportionality factor, which entails an improvement of fit for the seroprevalence of the varicella-zoster virus (VZV) in Belgium. Furthermore, we address the impact on the estimation of the basic reproduction number, using non-parametric bootstrapping to account for different sources of variability and using multi-model inference to deal with model selection uncertainty. The proposed method makes it possible to obtain important information on transmission dynamics that cannot be inferred from approaches traditionally applied hitherto.Comment: 25 pages, 6 figure

Serological survey of toxoplasmosis Transvaal

Thirty-seven per cent of 605 samples of human sera collected from four ethnic groups in South Africa gave a positive Toxoplasma indirect fluorescent antibody test at a dilution 01 1/16 or higher. The incidences in Indians (58%) and Coloureds (43%) were significantly higher than in Blacks (29%) and Whites (32%). These differences were regarded as being due to cultural rather than to socioeconomic factors. Some evidence for the importance of contact with felines in the epidemiology of toxoplasmosis is presented.S. Afr. Med. J., 48, 1707 (1974

Serological Survey of Pigs From a Slaughterhouse in Jakarta, Indonesia

Maksud dan tujuan dari survey ini ialah untuk mempelajari akan kemungkinannya he­wan-hewan babi memegang peranan sebagai reservoir ataupun amplifier dari penyakit-penyakit zoonotic di Pulau Jawa. Survey ini di­jalankan bersama-sama dengan Namru-2 di Jakarta. Sebagian besar specimens yang berupa darah, berasal dari babi babi yang akan dipotong dirumah pemotongan hewan babi di Jakarta Barat, babi-babi tersebut ada yang berasal dari Jawa Tengah, Jawa Barat, serta sebagian lagi berasal dari babi-babi milik rakyat di daerah Kapok. Pengambilan specimens dilakukan sehari sebelum babi-babi tadi dipotong. Setiap pagi lebih kurang 150 ekor babi dipotong, dimana umurnya berkisar antara enam hingga 24 bulan. Pada survey ini telah dikumpulkan 399 specimens, sebanyak 227 specimens berasal dari babi-babi betina, 159 specimens berasal dari babi-babi jantan, serta 13 specimens berasal dari babi-babi jantan kebiri. Hasil Pemeriksaan Laboratorium. Pemeriksaan terhadap Toxoplasma. Dari 166 sera yang berasal dari babi-babi Jawa Barat sebanyak 46 (28 percent) me-nunjukan hasil positif (titer 1 : 8 atau lebih j Sedangkan 235 sera berasal dari babi-babi Jawa Tengah , hany a sebanyak 17(7percent yang menunjukan hasil positif (titer 1 : 8). Titer yang lebih tinggi (1 : 1024) juga di­temukan pada babi-babi yang berasal dari Jawa Barat.Pemeriksaan terhadap Brucella suis. Titer 1 : 320 masih diketemukan pada semua group, akan tetapi sebagian besar serum me­nunjukan hasil negatip. Sebagian kecil sera yang berasal dari babi-babi tua dari Jawa-Barat menunjukan adanya anti­body yang lebih tinggi dari pada babi-babi muda.Pemeriksaan terhadap penyakit Japanese Encephalitis. Pada semua golongan umur dari geographical-group dari babi-babi menunjuk­an adanya anti-body terhadap J.E. Sera yang negatip lebih banyak berasal dari babi-babi Jawa Tengah.Pemeriksaan terhadap penyakit Influenza. Titer yang menyolok terhadap penyakit Influenza A2 Hongkong terdapat pada babi-babi golongan muda maupun tua baik yang berasal dari Jawa Tengah maupun yang ber­asal dari Jawa-Barat. Meskipun demikian, babi-babi dari Jawa Barat lebih banyak menunjukan hasil yang positip dari pada berasal dari Jawa Tengah.Pemeriksaan terhadap Leptospira. Kebanyakan serum menunjukan adanya anti-body terhadap L. sentot L. pomona dan L. bangkinang. Sebagian besar serum yang positip berasal dari babi-babi Jawa Tengah