Dengue vector control and surveillance during a major outbreak in a coastal Red Sea area in Sudan

Abstract

An unprecedented dengue outbreak occurred in 2010 in Port Sudan city, Sudan. Dengue incidence was 94 cases per 10 000 observed over 17 epidemiological weeks (total cases = 3 765). We report here the impact of the vector control response plan to the outbreak, which mainly entailed house inspection and insecticide space spraying. In total 3 048 houses were inspected during vector surveillance and 19 794 larvae and 3 240 pupae of Aedes aegypti were collected. Entomological indices decreased during the period: house index declined from 100% to 16% (F = 57.8, P < 0.001) and pupal/person (P/P) index from 0.77 to 0.10 (F = 3.06, P < 0.01) in weeks 9 and 21 respectively. This decline was accompanied by a decrease in cases from a peak of 341 cases in week 13 to zero in week 29 and the end of the outbreak. There was a significant correlation between the entomological parameters and dengue incidence (R 2 = 0.83, F= 23.9, P < 0.001). Integrated epidemiological and vector surveillance is essential to an effective dengue control programme Surveillance du vecteur de la dengue et actions de lutte pendant une importante flambée dans une zone côtière de la Mer rouge au Soudan RÉSUMÉ Une flambée de dengue sans précédent s'est produite en 2010 dans la ville de Port Soudan (Soudan). L'incidence de la dengue était de 94 cas pour 10 000 observés pendant 17 semaines épidémiologiques (nombre total de cas = 3 765). Nous présentons ici l'impact du plan de riposte visant à lutter contre le vecteur de la flambée. Ce plan consistait principalement en l'inspection des logements et la pulvérisation d'insecticides. Au total, 3 048 logements ont été inspectés pendant la surveillance du vecteur et 19 794 larves et 3 240 nymphes d'Aedes aegypti ont été recueillies. Les indices entomologiques ont diminué pendant la période : l'indice « habitations » est passé de 100 % à 16 % (F = 57,8 ; P < 0,001) et l'indice nymphe/personne est passé de 0,77 à 0,10 (F = 3,06 ; P < 0,01) au cours des semaines 9 et 21 respectivement. Cette diminution a été accompagnée par une diminution du nombre de cas, passant d'un pic de 341 cas en semaine 13 à zéro en semaine 29 et à la fin de la flambée. Une corrélation significative a été retrouvée entre les paramètres entomologiques et l'incidence de la dengue (R 2 = 0,83 ; F= 23,9 ; P < 0,001). Une surveillance vectorielle et épidémiologique intégrée est essentielle pour garantir l'efficacité d'un programme de lutte contre la dengue.

Containment measures for emerging and re-emerging vector-borne and other infectious diseases of poverty in urban settings: a scoping review

“…Healthcare provision measures included: health infrastructure improvements, such as the construction of new clinics, treatment centres, or hospitals [20, 24, 28, 30, 34, 38, 39, 45, 48] ( n =  9, 29%); improved case management [21, 27, 30, 33, 34, 36, 41] ( n =  7, 23%); appointment of public health officers and reorientation of specialists [19, 22, 24, 28, 36, 48] ( n =  6, 19%); training of doctors, community health workers, and other professionals [22, 28, 38, 39] ( n =  4, 13%); provision of pre- or post-exposure prophylaxis [21, 30, 37] ( n =  3, 10%); reactive vaccination campaigns [29, 41, 47] ( n =  3, 10%); introduction of treatment beds [24, 46] ( n =  2, 6%); use of new technology for diagnosis and treatment [24, 27] ( n =  2, 6%); timely hospital admission and effective triage of patients [40] ( n =  1, 3%), and safe transfer of identified cases [40] ( n =  1, 3%). Psychosocial support was also provided in one study [25] ( n =  1, 3%).…”

“…Epidemiological investigation and/or surveillance measures consisted of: the setting up or improvement of surveillance systems [19, 24, 26, 27, 30, 33, 36, 37, 40, 49] ( n =  10, 32%); active case-finding and contact tracing [25–28, 34, 37, 49] ( n =  7, 23%); collection of serological samples and documentation of cases [22, 28, 37] ( n =  3, 10%); entomological surveys and mapping [22–24] ( n =  3, 10%); screening of all arrivals and departures in and out of the country by land, air, and sea [29, 49] ( n =  2, 6%); operational studies for testing case definitions [22] ( n =  1, 3%); and establishment of a phone-based alert management system [37] ( n =  1, 3%). Intervention materials were real-time polymerase chain reaction (PCR), dashboards, and mobile phones [29, 44] ( n =  2, 6%).…”

“…Environmental and sanitary measures focused mainly on the isolation or quarantine of symptomatic individuals or close contacts [25, 26, 29, 34–36, 38–40, 43, 48] ( n =  11, 35%) and vector source reduction and chemical vector control measures in the case of vector-borne diseases [23, 24, 27, 31–33, 42, 44] ( n =  8, 26%). Other types of measures included: decontamination of the environment [21, 23, 37, 38] ( n =  4, 13%); safe burial practices [34, 36, 45] ( n =  3, 10%); closing of public and entertainment facilities [39, 48] ( n =  2, 6%); and water purification [24, 30] ( n =  2, 6%).…”

“…Campus quarantine was also used in one case [43] ( n =  1, 3%). The intervention materials mostly consisted of larvicides, insecticides, insecticide treated bed nets, and material for water filtration and mosquito collection [23, 27, 31–33, 42, 50] ( n =  7, 23%).…”

“…Community-based measures focused mainly on: involvement and training of community volunteers [33, 35, 36, 38, 49] ( n =  5, 16%); awareness campaigns [20, 30, 31, 40, 41] ( n =  5, 16%); and public education [31, 33, 41, 49] ( n =  4, 13%). They also included community-based surveillance or case-finding [30, 35, 36] ( n =  3, 10%) and social mobilization [22, 36] ( n =  2, 6%).…”