C. S. Heymann

Bio: C. S. Heymann is an academic researcher. The author has contributed to research in topics: Blood serum & Neutralization. The author has an hindex of 6, co-authored 7 publications receiving 110 citations.

Zika: the origin and spread of a mosquito-borne virus.

Abstract: Introduction Zika, a flavivirus transmitted mainly by mosquitos in the genus Aedes, was discovered in 1947 in Uganda. (1) From the 1960s to 1980s, human infections were found across Africa and Asia, typically accompanied by mild illness. The first large outbreak of disease caused by Zika infection was reported from the island of Yap (Federated States of Micronesia) in 2007, as the virus moved from south-east Asia across the Pacific. During an outbreak in French Polynesia in 2013-2014, Guillain-Barre syndrome was linked to Zika infection and cases of microcephaly in newborn children were also retrospectively linked to this outbreak. The World Health Organization (WHO) received the first reports of locally-transmitted infection from Brazil in May 2015. In July 2015, health ministry officials from Brazil reported an association between Zika virus infection and Guillain-Barre syndrome in adults. In October 2015, WHO received reports from Brazil of microcephaly in babies whose mothers had been exposed to Zika during pregnancy. At this time, there was no proof of a causal link between Zika infection and these neurological complications. In February 2016, as infection moved rapidly through the range occupied by Aedes mosquitos in the Americas, WHO declared that Zika infection associated with microcephaly and other neurological disorders constituted a Public Health Emergency of International Concern (PHEIC). By the start of February 2016, local transmission of Zika infection had been reported from more than 20 countries and territories in the Americas and an outbreak numbering thousands of cases was under way in Cabo Verde in western Africa. Beyond the range of its mosquito vectors, Zika virus infections are expected to be carried worldwide by people as they travel and be transmitted by travellers to sexual partners who have not been to places where the virus is endemic. Methods To illustrate the spread of Zika virus and associated neurological complications, we did a literature search in PubMed using "Zika" and "ZIKV" as the search terms and cross-checked our findings for completeness against other published reviews. (2, 3) In addition, we drew on formal notifications to WHO under the International Health Regulations (IHR), (4) which are archived in the WHO Event Information Site (EIS). EIS contains information about public health events of potential international concern notified to WHO as required by the IHR. EIS notifications sometimes contain confidential patient information and therefore are not publicly available. Other details of specific events can be provided by the authors on request. Results The first reported case of Zika virus dates to 1947 when the virus was isolated in samples taken from a captive sentinel rhesus monkey by scientists conducting routine surveillance for yellow fever in the Zika forest of Uganda. (1) The virus was recovered from Aedes (Stegomyia) africanus, caught on a tree platform in the forest. (1) Laboratory infection experiments showed the virus to be neurotropic in mice. (5) The timeline presented in this paper includes numerous serological surveys that purportedly detected antibodies to Zika virus in the 1950s and 1960s in Africa and Asia. Because serological (antibody detection) tests for Zika cross-react with antibodies stimulated by other viral infections, the presence of Zika virus is ideally confirmed by the detection of viral nucleic acids by polymerase chain reaction (PCR) testing or by virus isolation. A chronological map of the presence of Zika in those countries for which there is evidence of autochthonous transmission by mosquitos is presented in Fig. 1. The map excludes the many countries from which imported Zika infections have been reported. The country-by-country spread of Zika virus infections, from the earliest published report in 1947 to a World Health Organization, avenue Appia 20, 1211 Geneva 27, Switzerland. January 2014 is summarized in Table 1. …

Mosquito-borne arboviruses of African origin: review of key viruses and vectors

Abstract: Key aspects of 36 mosquito-borne arboviruses indigenous to Africa are summarized, including lesser or poorly-known viruses which, like Zika, may have the potential to escape current sylvatic cycling to achieve greater geographical distribution and medical importance. Major vectors are indicated as well as reservoir hosts, where known. A series of current and future risk factors is addressed. It is apparent that Africa has been the source of most of the major mosquito-borne viruses of medical importance that currently constitute serious global public health threats, but that there are several other viruses with potential for international challenge. The conclusion reached is that increased human population growth in decades ahead coupled with increased international travel and trade is likely to sustain and increase the threat of further geographical spread of current and new arboviral disease.

Studies on the Biting Habits and Medical Importance of East African Mosquitos in the Genus Aëdes. I. Subgenera Aëdimorphus, Banksinella and Dunnius.

Abstract: The biting behaviour of East African species of Aedes in the subgenera Aedimorphus, Banksinella and Dunnius, as shown in numerous series of 24-hr, catches made predominantly in Uganda, is discussed. It is shown that with the single exception of A. (A.) natronius Edw., which is arboreal, all the species encountered have been most prevalent at ground level. They bite mostly by day, but A. cumminsi (Theo.) shows a marked peak of activity from just before to just after sunset, and A. natronius is crepuscular. When, however, samples were obtained in environments less favoured than the forest floor, and in which the mosquito concerned was less abundant, the biting cycle might be altered. Thus various species which were essentially diurnal at ground level in forest might be nocturnal in the canopy or in banana plantations.In some cases there seemed to be a tendency towards a group pattern of behaviour. For example, in the abnormalis (Theo.) and tarsalis (Newst.) groups of Edwards it was found that at least three species showed very similar biting cycles. A fourth species, A. nigricephalus (Theo.), which occurs in Nigeria, is reported there to differ in its biting habits, and is also strikingly different in appearance and in the structure of the terminalia.Members of all three subgenera have been involved in various isolations of virus, but it is not possible to prove that they, rather than other species of Aedes included in the infected lots, were the vector mosquitos, except in the case of the A. tarsalis group, from which there have been two definite isolations of Rift Valley fever virus, and in that of A. circumluteolus (Theo.), which has been shown by recent work in South and East Africa to be of major importance, well over 20 isolations of virus having been made from this species. So far as is known at present, seven separate viruses and one distinct variant have been isolated from A. circumluteolus, and other members of the subgenus Banksinella also appear to be involved in transmission.

Arboviruses pathogenic for domestic and wild animals.

Abstract: The objective of this chapter is to provide an updated and concise systematic review on taxonomy, history, arthropod vectors, vertebrate hosts, animal disease, and geographic distribution of all arboviruses known to date to cause disease in homeotherm (endotherm) vertebrates, except those affecting exclusively man. Fifty arboviruses pathogenic for animals have been documented worldwide, belonging to seven families: Togaviridae (mosquito-borne Eastern, Western, and Venezuelan equine encephalilitis viruses; Sindbis, Middelburg, Getah, and Semliki Forest viruses), Flaviviridae (mosquito-borne yellow fever, Japanese encephalitis, Murray Valley encephalitis, West Nile, Usutu, Israel turkey meningoencephalitis, Tembusu and Wesselsbron viruses; tick-borne encephalitis, louping ill, Omsk hemorrhagic fever, Kyasanur Forest disease, and Tyuleniy viruses), Bunyaviridae (tick-borne Nairobi sheep disease, Soldado, and Bhanja viruses; mosquito-borne Rift Valley fever, La Crosse, Snowshoe hare, and Cache Valley viruses; biting midges-borne Main Drain, Akabane, Aino, Shuni, and Schmallenberg viruses), Reoviridae (biting midges-borne African horse sickness, Kasba, bluetongue, epizootic hemorrhagic disease of deer, Ibaraki, equine encephalosis, Peruvian horse sickness, and Yunnan viruses), Rhabdoviridae (sandfly/mosquito-borne bovine ephemeral fever, vesicular stomatitis-Indiana, vesicular stomatitis-New Jersey, vesicular stomatitis-Alagoas, and Coccal viruses), Orthomyxoviridae (tick-borne Thogoto virus), and Asfarviridae (tick-borne African swine fever virus). They are transmitted to animals by five groups of hematophagous arthropods of the subphyllum Chelicerata (order Acarina, families Ixodidae and Argasidae-ticks) or members of the class Insecta: mosquitoes (family Culicidae); biting midges (family Ceratopogonidae); sandflies (subfamily Phlebotominae); and cimicid bugs (family Cimicidae). Arboviral diseases in endotherm animals may therefore be classified as: tick-borne (louping ill and tick-borne encephalitis, Omsk hemorrhagic fever, Kyasanur Forest disease, Tyuleniy fever, Nairobi sheep disease, Soldado fever, Bhanja fever, Thogoto fever, African swine fever), mosquito-borne (Eastern, Western, and Venezuelan equine encephalomyelitides, Highlands J disease, Getah disease, Semliki Forest disease, yellow fever, Japanese encephalitis, Murray Valley encephalitis, West Nile encephalitis, Usutu disease, Israel turkey meningoencephalitis, Tembusu disease/duck egg-drop syndrome, Wesselsbron disease, La Crosse encephalitis, Snowshoe hare encephalitis, Cache Valley disease, Main Drain disease, Rift Valley fever, Peruvian horse sickness, Yunnan disease), sandfly-borne (vesicular stomatitis-Indiana, New Jersey, and Alagoas, Cocal disease), midge-borne (Akabane disease, Aino disease, Schmallenberg disease, Shuni disease, African horse sickness, Kasba disease, bluetongue, epizootic hemorrhagic disease of deer, Ibaraki disease, equine encephalosis, bovine ephemeral fever, Kotonkan disease), and cimicid-borne (Buggy Creek disease). Animals infected with these arboviruses regularly develop a febrile disease accompanied by various nonspecific symptoms; however, additional severe syndromes may occur: neurological diseases (meningitis, encephalitis, encephalomyelitis); hemorrhagic symptoms; abortions and congenital disorders; or vesicular stomatitis. Certain arboviral diseases cause significant economic losses in domestic animals-for example, Eastern, Western and Venezuelan equine encephalitides, West Nile encephalitis, Nairobi sheep disease, Rift Valley fever, Akabane fever, Schmallenberg disease (emerged recently in Europe), African horse sickness, bluetongue, vesicular stomatitis, and African swine fever; all of these (except for Akabane and Schmallenberg diseases) are notifiable to the World Organisation for Animal Health (OIE, 2012).

Genome-Scale Phylogeny of the Alphavirus Genus Suggests a Marine Origin

Abstract: The genus Alphavirus comprises a diverse group of viruses, including some that cause severe disease. Using full-length sequences of all known alphaviruses, we produced a robust and comprehensive phylogeny of the Alphavirus genus, presenting a more complete evolutionary history of these viruses compared to previous studies based on partial sequences. Our phylogeny suggests the origin of the alphaviruses occurred in the southern oceans and spread equally through the Old and New World. Since lice appear to be involved in aquatic alphavirus transmission, it is possible that we are missing a louse-borne branch of the alphaviruses. Complete genome sequencing of all members of the genus also revealed conserved residues forming the structural basis of the E1 and E2 protein dimers.