Statistics for Spatial Data.

Beginning with Emlen (1966) and MacArthur and Pianka (1966) and extending through the last ten years, several authors have sought to predict the foraging behavior of animals by means of mathematical models. These models are very similar,in that they all assume that the fitness of a foraging animal is a function of the efficiency of foraging measured in terms of some "currency" (Schoener, 1971) -usually energy- and that natural selection has resulted in animals that forage so as to maximize this fitness. As a result of these similarities, the models have become known as "optimal foraging models"; and the theory that embodies them, "optimal foraging theory." The situations to which optimal foraging theory has been applied, with the exception of a few recent studies, can be divided into the following four categories: (1) choice by an animal of which food types to eat (i.e., optimal diet); (2) choice of which patch type to feed in (i.e., optimal patch choice); (3) optimal allocation of time to different patches; and (4) optimal patterns and speed of movements. In this review we discuss each of these categories separately, dealing with both the theoretical developments and the data that permit tests of the predictions. The review is selective in the sense that we emphasize studies that either develop testable predictions or that attempt to test predictions in a precise quantitative manner. We also discuss what we see to be some of the future developments in the area of optimal foraging theory and how this theory can be related to other areas of biology. Our general conclusion is that the simple models so far formulated are supported are supported reasonably well by available data and that we are optimistic about the value both now and in the future of optimal foraging theory. We argue, however, that these simple models will requre much modification, espicially to deal with situations that either cannot easily be put into one or another of the above four categories or entail currencies more complicated that just energy.

Citation classic - optimal foraging - a selective review of theory and tests

Background
Malaria is an important cause of illness and death in many parts of the world, especially in sub-Saharan Africa. There has been a renewed emphasis on preventive measures at community and individual levels. Insecticide-treated nets (ITNs) are the most prominent malaria preventive measure for large-scale deployment in highly endemic areas.

Objectives
To assess the impact of insecticide-treated bed nets or curtains on mortality, malarial illness (life-threatening and mild), malaria parasitaemia, anaemia, and spleen rates.

Search methods
I searched the Cochrane Infectious Diseases Group trials register (January 2003), CENTRAL (The Cochrane Library, Issue 1, 2003), MEDLINE (1966 to October 2003), EMBASE (1974 to November 2002), LILACS (1982 to January 2003), and reference lists of reviews, books, and trials. I handsearched journals, contacted researchers, funding agencies, and net and insecticide manufacturers.

Selection criteria
Individual and cluster randomized controlled trials of insecticide-treated bed nets or curtains compared to nets without insecticide or no nets. Trials including only pregnant women were excluded.

Data collection and analysis
The reviewer and two independent assessors reviewed trials for inclusion. The reviewer assessed the risk of bias in the trials, and extracted and analysed data.

Main results
Fourteen cluster randomized and eight individually randomized controlled trials met the inclusion criteria. Five trials measured child mortality: ITNs provided 17% protective efficacy (PE) compared to no nets (relative rate 0.83, 95% confidence interval (CI) 0.76 to 0.90), and 23% PE compared to untreated nets (relative rate 0.77, 95% CI 0.63 to 0.95). About 5.5 lives (95% CI 3.39 to 7.67) can be saved each year for every 1000 children protected with ITNs. In areas with stable malaria, ITNs reduced the incidence of uncomplicated malarial episodes in areas of stable malaria by 50% compared to no nets, and 39% compared to untreated nets; and in areas of unstable malaria: by 62% for compared to no nets and 43% compared to untreated nets for Plasmodium falciparum episodes, and by 52% compared to no nets and 11% compared to untreated nets for P. vivax episodes. When compared to no nets and in areas of stable malaria, ITNs also had an impact on severe malaria (45% PE, 95% CI 20 to 63), parasite prevalence (13% PE), high parasitaemia (29% PE), splenomegaly (30% PE), and their use improved the average haemoglobin level in children by 1.7% packed cell volume.

Authors' conclusions
ITNs are highly effective in reducing childhood mortality and morbidity from malaria. Widespread access to ITNs is currently being advocated by Roll Back Malaria, but universal deployment will require major financial, technical, and operational inputs.

Insecticide‐treated bed nets and curtains for preventing malaria

This report updates and combines earlier versions of guidelines for the prevention and treatment of opportunistic infections (OIs) in HIV-infected adults (i.e., persons aged >/=18 years) and adolescents (i.e., persons aged 13--17 years), last published in 2002 and 2004, respectively. It has been prepared by the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and the HIV Medicine Association (HIVMA) of the Infectious Diseases Society of America (IDSA). The guidelines are intended for use by clinicians and other health-care providers, HIV-infected patients, and policy makers in the United States. These guidelines address several OIs that occur in the United States and five OIs that might be acquired during international travel. Topic areas covered for each OI include epidemiology, clinical manifestations, diagnosis, prevention of exposure; prevention of disease by chemoprophylaxis and vaccination; discontinuation of primary prophylaxis after immune reconstitution; treatment of disease; monitoring for adverse effects during treatment; management of treatment failure; prevention of disease recurrence; discontinuation of secondary prophylaxis after immune reconstitution; and special considerations during pregnancy. These guidelines were developed by a panel of specialists from the United States government and academic institutions. For each OI, a small group of specialists with content-matter expertise reviewed the literature for new information since the guidelines were last published; they then proposed revised recommendations at a meeting held at NIH in June 2007. After these presentations and discussion, the revised guidelines were further reviewed by the co-editors; by the Office of AIDS Research, NIH; by specialists at CDC; and by HIVMA of IDSA before final approval and publication. The recommendations are rated by a letter that indicates the strength of the recommendation and a Roman numeral that indicates the quality of evidence supporting the recommendation, so that readers can ascertain how best to apply the recommendations in their practice environments. Major changes in the guidelines include 1) greater emphasis on the importance of antiretroviral therapy for the prevention and treatment of OIs, especially those OIs for which no specific therapy exists; 2) information regarding the diagnosis and management of immune reconstitution inflammatory syndromes; 3) information regarding the use of interferon-gamma release assays for the diagnosis of latent Mycobacterium tuberculosis (TB) infection; 4) updated information concerning drug interactions that affect the use of rifamycin drugs for prevention and treatment of TB; 5) the addition of a section on hepatitis B virus infection; and 6) the addition of malaria to the list of OIs that might be acquired during international travel. This report includes eleven tables pertinent to the prevention and treatment of OIs, a figure that pertains to the diagnois of tuberculosis, a figure that describes immunization recommendations, and an appendix that summarizes recommendations for prevention of exposure to opportunistic pathogens.

Guidelines for prevention and treatment of opportunistic infections in HIV-infected adults and adolescents: recommendations from CDC, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America.

The first edition of this reference work was published in 1898, and the last update was published in 1972. This current edition is written by six major contributors and contains either rewritten or new chapters, including one 29-page chapter entitled "Ophthalmology in the Tropics" by F. C. Rodger, MD. Not only is this material valuable to physicians in endemic areas, but it is also important for travelers to the tropics who may return home with these diseases. Most of the chapters discuss the following aspects of tropical disease: cause, transmission, immunology, epidemiology, geographical distribution, pathologic condition, clinical findings, and diagnosis (including laboratory findings, treatment, and prevention). Beside chapters on infections, there are chapters on disorders due to heat, nutritional diseases, and venoms and poisons, and appendices on protozoology, helminthology, entomology, and clinical pathologic conditions. Excellent illustrations of end-stage pathologic conditions are disconcerting. Ophthalmologists would be most interested in the discussion

Manson's Tropical Diseases

A preliminary evaluation was undertaken on the safety aspects in mosquito net impregnation with lambdacyhalothrin, on the operators and users of the treated nets. The detection by HPLC of one of the principal metabolites of lambdacyhalothrin, 3-phenoxy benzoic acid (3-PBA) in blood samples of the users and operators in very small quantities (0.01 to 0.02 ng/microliters) showed that absorption of the insecticide was minimum. Clinical examination and analysis of different biochemical parameters in blood and serum samples showed in spite of the minimal absorption of the insecticide, there was no immediate adverse effect.

Preliminary evaluation on safety aspects in mosquito net impregnation with lambdacyhalothrin.

Different Electric-Mat-Device (EMD) vaporizers and bioallethrin impregnated mats were evaluated for the knockdown and mortality in the adults of Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti. Percentage knockdown of 80-100 was recorded throughout the test period of 11 hours. However, the percentage mortality observed was not appreciable in all types of EMD vaporizers. Device "A" was found to be effective only against Ae. aegypti. Devices "e" and "D" showed moderate effects against An. stephensi and Ae. aegypti. Only device "8" was found to give appreciable mortality in all three vector mosquito species compared to other devices which may be attributed to the uniform release rate (2 mglhour) of bioallethrin.

Evaluation of EMD vaporizers and bioallethrin vaporizing mats against mosquito vectors.

Evaluation of two new juvenile hormone compounds against mosquito vectors.

Risk of infection of Wuchereria bancrofti to humans by Culex quinquefasciatus in Pondicherry and its relationship with microfilaria prevalence.

An out break of acute bacillary dysentery in a village called Dhamasin in Hooghly district of West Bengal was investigated during March 1984. Forty seven percent of families were affected. A total of 91 cases and 2 deaths occurred amongst 937 people giving an over all attack rate of 9.7% and a case fatality rate of 2.2 percent. Highest attack rate (22.7%) was observed in below one year age group. Multiple drug resistant Shigella dysentery type 1 strains were isolated for the first time from 6 out of 22 cases sampled at the domiciliary level. The organism was never isolated earlier during last ten years of surveillance in the infectious Diseases Hospital, Calcutta. Identification of nature of this outbreak and it's causative agent helped to realise the potentiality of extensive spread and paved the way for further investigations. Public health authorities were buffled as the rapid spread of the disease throughout the entire state of West Bengal could not be contained in spite of instituting all probable control measures on war footing.

P. K. Das

Papers

Preliminary evaluation on safety aspects in mosquito net impregnation with lambdacyhalothrin.

Evaluation of EMD vaporizers and bioallethrin vaporizing mats against mosquito vectors.

Evaluation of two new juvenile hormone compounds against mosquito vectors.

Risk of infection of Wuchereria bancrofti to humans by Culex quinquefasciatus in Pondicherry and its relationship with microfilaria prevalence.

Multidrug resistant epidemic shigellosis in a village in west Bengal, 1984.