Source: | |
Date: | August 8, 2007 |
"Public health is everyone's responsibility. In a world faced by the threat of newly emerging and re-emerging infectious diseases, it is critical to determine if costly and potentially socially harsh NPI measures can save lives and reduce the numbers of those infected,"
This work was funded by the Centers for Disease Control and Prevention and conducted by the University of Michigan Center for the History of Medicine and the CDC Division of Global Migration and Quarantine.
The 43 cities examined in this study were:
Note: This story has been adapted from a news release issued by University of Michigan Health System.
http://www.sciencedaily.com/releases/2007/08/070807165255.htm
http://www.sciencedaily.com/news/health_medicine/infectious_diseases/
Donor Funding for Health in Low- & Middle- Income Countries, 2001-2005
Donor governments, including the United States and European nations, provide the bulk of international funding for health in low- and middle- income countries each year. Despite significant increases in such funding, however, it still falls short of need as estimated by the World Health Organization’s Commission on Macroeconomics and Health. This report prepared by the Kaiser Family Foundation and the Center for Strategic and International Studies (CSIS) provides an analysis of donor commitments for health and includes detailed tables and charts.
see report
http://www.kff.org/hivaids/7679.cfm
Synopses West Nile Fever–a Reemerging Mosquito-Borne Viral Disease in Europe
The 1996-97 outbreak of West Nile fever in and near Bucharest, Romania, with more than 500 clinical cases and a case-fatality rate approaching 10% (1-3), was the largest outbreak of arboviral illness in Europe since the Ockelbo-Pogosta-Karelian fever epidemic caused by Sindbis virus in northern Europe in the 1980s. This latest outbreak reaffirmed that mosquito-borne viral diseases may occur on a mass scale, even in temperate climates. West Nile virus is a member of the Japanese encephalitis antigenic complex of the genus Flavivirus, family Flaviviridae (4). All known members of this complex (Alfuy, Japanese encephalitis, Kokobera, Koutango, Kunjin, Murray Valley encephalitis, St. Louis encephalitis, Stratford, Usutu, and West Nile viruses) are transmissible by mosquitoes and many of them can cause febrile, sometimes fatal, illnesses in humans. West Nile virus was first isolated from the blood of a febrile woman in the West Nile district of Uganda in 1937 (5) and was subsequently isolated from patients, birds, and mosquitoes in Egypt in the early 1950s (6-7). The virus was soon recognized as the most widespread of the flaviviruses, with geographic distribution including Africa and Eurasia. Outside Europe (Figure), the virus has been reported from Algeria, Asian Russia, Azerbaijan, Botswana, Central African Republic, Côte d'Ivoire, Cyprus, Democratic Republic of Congo (former Zaire), Egypt, Ethiopia, India, Israel, Kazakhstan, Madagascar, Morocco, Mozambique, Nigeria, Pakistan, Senegal, South Africa, Tajikistan, Turkmenia, Uganda, and Uzbekistan. Furthermore, West Nile virus antibodies have been detected in human sera from Armenia, Borneo, China, Georgia, Iraq, Kenya, Lebanon, Malaysia, the Philippines, Sri Lanka, Sudan, Syria, Thailand, Tunisia, and Turkey (8-10). Kunjin virus is closely related to West Nile virus (11,12), representing a counterpart or subtype for Australia and Southeast Asia; some West Nile virus seroreactions in Southeast Asia may, in fact, represent antibodies to Kunjin virus. West Nile Virus EcologyArthropod VectorsMosquitoes, largely bird-feeding species, are the principal vectors of West Nile virus. The virus has been isolated from 43 mosquito species, predominantly of the genus Culex (Table 1). In Africa and the Middle East, the main vector is Cx. univittatus (although Cx. poicilipes, Cx. neavei, Cx. decens, Aedes albocephalus, or Mimomyia spp. play an important role in certain areas). In Europe, the principal vectors are Cx. pipiens, Cx. modestus, and Coquillettidia richiardii, and in Asia, Cx. quinquefasciatus, Cx. tritaeniorhynchus, and Cx. vishnui predominate. Successful experimental transmission of the virus has been described in Culiseta longiareolata, Cx. bitaeniorhynchus, and Ae. albopictus (8,13). Transovarial transmission of the virus has been demonstrated in Cx. tritaeniorhynchus, Ae. aegypti, and Ae. albopictus, though at low rates. Virus isolations have occasionally been reported from other hematophagous arthropods (e.g., bird-feeding argasid [soft] or amblyommine [hard] ticks) (Table 1), and experimental transmission has been observed in Ornithodoros savignyi, O. moubata, O.maritimus, O. erraticus, Rhipicephalus sanguineus, R. rossicus, Dermacentor reticulatus, and Haemaphysalis leachii (8,13). Vertebrate HostsWild birds are the principal hosts of West Nile virus. The virus has been isolated from a number of wetland and terrestrial avian species in diverse areas (7-10,14-16). High, long-term viremia, sufficient to infect vector mosquitoes, has been observed in infected birds (7,17,18). The virus persists in the organs of inoculated ducks and pigeons for 20 to 100 days (18). Migratory birds are therefore instrumental in the introduction of the virus to temperate areas of Eurasia during spring migrations (12,14-16,19). Rarely, West Nile virus has been isolated from mammals (Arvicanthis niloticus, Apodemus flavicollis, Clethrionomys glareolus, sentinel mice and hamsters, Lepus europaeus, Rousettus leschenaulti, camels, cattle, horses, dogs, Galago senegalensis, humans) in enzootic foci (8-10). Mammals are less important than birds in maintaining transmission cycles of the virus in ecosystems. Only horses and lemurs (20) have moderate viremia and seem to support West Nile virus circulation locally. Frogs (Rana ridibunda) also can harbor the virus, and their donor ability for Cx. pipiens has been confirmed (21). Transmission CyclesAlthough Palearctic natural foci of West Nile virus infections are mainly situated in wetland ecosystems (river deltas or flood plains) and are characterized by the bird-mosquito cycle, argasid and amblyommine ticks may serve as substitute vectors and form a bird-tick cycle in certain dry and warm habitats lacking mosquitoes. Even a frog-mosquito cycle (21) may function under certain circumstances. In Europe, West Nile virus circulation is confined to two basic types of cycles and ecosystems: rural (sylvatic) cycle (wild, usually wetland birds and ornithophilic mosquitoes) and urban cycle (synanthropic or domestic birds and mosquitoes feeding on both birds and humans, mainly Cx. pipiens/molestus). The principal cycle is rural, but the urban cycle predominated in Bucharest during the 1996-97 outbreak (2,3). Circulation of West Nile fever in Europe is similar to that of St. Louis encephalitis in North America, where the rural cycle of exoanthropic birds—Cx. tarsalis alternates with the urban cycle of synanthropic birds—Cx. pipiens/quinquefasciatus. |
West Nile fever in humans usually is a febrile, influenzalike illness, characterized by an abrupt onset (incubation period is 3 to 6 days) of moderate to high fever (3 to 5 days, infrequently biphasic, sometimes with chills), headache (often frontal), sore throat, backache, myalgia, arthralgia, fatigue, conjunctivitis, retrobulbar pain, maculopapular or roseolar rash (in approximately half the cases, spreading from the trunk to the extremities and head), lymphadenopathy, anorexia, nausea, abdominal pain, diarrhea, and respiratory symptoms (9). Occasionally (<15% of cases), acute aseptic meningitis or encephalitis (associated with neck stiffness, vomiting, confusion, disturbed consciousness, somnolence, tremor of extremities, abnormal reflexes, convulsions, pareses, and coma), anterior myelitis, hepatosplenomegaly, hepatitis, pancreatitis, and myocarditis occur. Laboratory findings involve a slightly increased sedimentation rate and a mild leukocytosis; cerebrospinal fluid in patients with central nervous system involvement is clear, with moderate pleocytosis and elevated protein. The virus can be recovered from the blood for up to 10 days in immunocompetent febrile patients, as late as 22 to 28 days after infection in immunocompromised patients; peak viremia occurs 4 to 8 days postinfection. Recovery is complete (less rapid in adults than in children, often accompanied by long-term myalgias and weakness), and permanent sequelae have not been reported. Most fatal cases have been recorded in patients older than 50 years. Many of the West Nile fever symptoms have been reproduced in volunteers with underlying neoplastic disease who had been inoculated with virus to achieve pyrexia and oncolysis (22).
Table 1. Isolations of West Nile virus from hematophagous arthropods (7-10) | ||
Species | No. | Countries |
Mosquitoes |
|
|
Culex antennatusa | 6 | Egypt, Madagascar |
decens group | 8 | Madagascar |
ethiopicus | 1 | Ethiopia |
guiarti | 1 | Côte d Ivoire |
modestus | 3 | France, Russia |
neavei | 4 | Senegal, South Africa |
nigripes | 1 | Central African Republic |
perexiguus | 1 | Israel |
perfuscus group | 3 | Central African Republic, Senegal |
pipiensa | 7 | South Africa, Egypt, Israel, Romania, Czechland, Bulgariab |
poicilipes | 29 | Senegal |
pruina | 1 | Central African Republic |
quinquefasciatusa | 7 | India, Pakistan, Madagascar |
scottii | 1 | Madagascar |
theileria | 4 | South Africa |
tritaeniorhynchusa | 3 | Pakistan, India, Madagascar |
univittatusa | 51 | Egypt, Israel, South Africa, Madagascar |
vishnuia group | 6 | India, Pakistan |
weschei | 1 | Central African Republic |
sp. | 3 | Egypt, Algeria, Central African Republic |
Coquillettidia metallica | 1 | Uganda |
microannulata | 1 | South Africa |
richiardii | 5 | South Russia, Bulgariab |
Mansonia uniformis | 1 | Ethiopia |
Aedes aegyptia | 1 | Madagascar |
africanus | 1 | Central African Republic |
albocephalus | 35 | Madagascar |
albothorax | 1 | Kenya |
cantans | 7 | Slovakia, Ukraine, Bulgariab |
caspiusa | 1 | Ukraine |
circumluteolus | 2 | South Africa, Madagascar |
excrucians | 1 | Ukraine |
juppi caballus | 1 | South Africa |
madagascarensis | 1 | Madagascar |
vexans | 3 | Senegal, Russia |
Anopheles brunnipes | 1 | Madagascar |
coustani | 1 | Israel |
maculipalpis | 1 | Madagascar |
maculipennis | 3 | Portugal, Ukraine |
subpictus | 1 | India |
sp. | 1 | Madagascar |
Mimomyia hispida | 8 | Senegal |
lacustris | 4 | Senegal |
splendens | 6 | Senegal |
sp. | 2 | Senegal |
Aedeomyia africana | 1 | Senegal |
Soft ticks |
|
|
Argas hermannia | 3 | Egypt |
Ornithodoros capensisa | 5 | Azerbaijan |
Hard ticks |
|
|
Hyalomma marginatum | 5 | Astrakhan, Azerbaijan |
detritum | 1 | Turkmenistan |
Rhipicephalus turanicus | 1 | Azerbaijan |
muhsamae | 1 | Central African Republic |
Amblyomma variegatum | 1 | Central African Republic |
Dermacentor marginatusa | 1 | Moldavia |
aExperimental transmission of the virus also demonstrated. bDetected in mosquitoes by immunofluorescence assay. | ||
Hundreds of West Nile fever cases have been described in Israel and South Africa. The largest African epidemic, with approximately 3,000 clinical cases, occurred in an arid region of the Cape Province after heavy rains in 1974 (23). An outbreak with approximately 50 patients, eight of whom died, was described in Algeria in 1994 (1). Other cases or outbreaks have been observed in Azerbaijan, Central African Republic, Democratic Republic of Congo (former Zaire), Egypt, Ethiopia, India, Madagascar, Nigeria, Pakistan, Senegal, Sudan, and in a few European countries.
Equine disease, called Near Eastern equine encephalitis in Egypt and lourdige in France, was observed and experimentally reproduced as fever and diffuse encephalomyelitis with a moderate to high fatality rate in Egypt (24), France (c. 50 cases in 1962-65) (25), Italy (14 cases in 1998, six died or were euthanised) (R. Lelli, G. Ferrari, pers. comm.), Portugal (26) and Morocco (42 of 94 affected horses died) (27). In the 1960s, the biphasic, encephalomyelitic form, which causes staggering gait and weakness to paralysis of the hind legs, was apparent among infected semiferal horses in Camargue (25).
Inoculation of sheep with West Nile virus results in fever, abortion in pregnant ewes, and rare encephalitis, in contrast to the asymptomatic infection seen in pigs and dogs (9,28). Rabbits, adult albino rats, and guinea pigs are resistant to West Nile virus infection, but laboratory mice and Syrian hamsters are markedly susceptible; they often become ill with fatal encephalitis, even when inoculated peripherally (8). Adult rodents stressed or immunosuppressed by cold, isolation, cyclophosphamide, corticosterone, or bacterial endotoxin contract fatal encephalitis, even when an attenuated viral strain is given (29). Inoculation of rhesus and bonnet monkeys (but not cynomolgus monkeys or chimpanzees) causes fever, ataxia, and prostration with occasional encephalitis, tremor of extremities, pareses, or paralysis. Infection may be fatal or cause long-term virus persistence in survivors (5,6,30).
Birds usually do not show any symptoms when infected with West Nile virus. However, natural disease due to the virus has been observed in a pigeon in Egypt (7), and inoculation of certain avian species (e.g., pigeons, chickens, ducks, gulls, and corvids) causes occasional encephalitis and death or long-term virus persistence (7,10,17,18). Chick embryos may be killed by the virus (8).
In Europe, the presence of West Nile virus was indicated in 1958, when two Albanians had specific West Nile virus antibodies (31). The first European isolations of the virus were recorded in 1963 from patients and mosquitoes in the Rhône Delta (32) and from patients and Hyalomma marginatum ticks in the Volga Delta (33,34). West Nile virus was subsequently isolated in Portugal (35), Slovakia (36), Moldavia (37), Ukraine (38), Hungary (39), Romania (2), Czechland (40), and Italy (V. Deubel, G. Ferrari, pers. comm.).
The incidence of West Nile fever in Europe is largely unknown. In the 1960s, cases were observed in southern France (25), southern Russia (41), Spain (26), southwestern Romania (42), in the 1970s, 1980s, and 1990s in Belarus (43), western Ukraine (44), southeastern Romania (1,2), and Czechland (45). West Nile fever in Europe occurs during the period of maximum annual activity of mosquito vectors (July to September) (Table 2).
Table 2. West Nile Virus in Europe, 1960-1998 |
|
|
| ||
Country | Year | Species infected | HIa (%) | Neutralization (%) | Ref. |
Portugal, southern | 1967-1970 | Cattle, sheep | 15 |
| 26, 35 |
|
| Horses | 29 |
|
|
|
| Humans mosquitoes (1 isolate) | 3 | ||