Household survey of container-breeding mosquitoes and climatic factors influencing the prevalence of Aedes aegypti (Diptera: Culicidae) in Makkah City, Saudi Arabia.

OBJECTIVE: To investigate the prevalence of container breeding mosquitoes with emphasis on the seasonality and larval habitats of Aedes aegypti (Ae. aegypti) in Makkah City, adjoining an environmental monitoring and dengue incidence. METHODS: Monthly visits were performed between April 2008 and March 2009 to randomly selected houses. During each visit, mosquito larvae were collected from indoors and outdoors containers by either dipping or pipetting. Mosquitoes were morphologically identified. Data on temperature, relative humidity, rain/precipitations during the survey period was retrieved from governmental sources and analyzed. RESULTS: The city was warmer in dry season (DS) than wet season (WS). No rain occurred at all during DS and even precipitations did fall, wetting events were much greater during WS. Larval survey revealed the co-breeding of Aedes, Culex and Anopheles in a variety of artificial containers in and around homes. 32 109 larvae representing 1st , 2nd, 3rd, and 4th stages were collected from 22 618 container habitats. Culicines was far the commonest and Aedes genus was as numerous as the Culex population. Ae. aegypti larval abundance exhibited marked temporal variations, overall, being usually more abundant during WS. Ten types of artificial containers were found with developing larvae. 70% of these habitats were located indoors. 71.42% of indoor containers were permanent and 28.58% was semi-permanent during WS. Cement tanks was the only container type permanent during DS. Ae. aegypti larval indices (CI, HI, BI) recorded were greater during WS. CONCLUSIONS: Taken together, these results indicate a high risk of dengue transmission in the holy city.

Clinical profile and outcome of hospitalized patients during first outbreak of dengue in Makkah, Saudi Arabia.

OBJECTIVE: To describe clinical profile of patients with dengue virus infection hospitalized at a single center during the first outbreak of dengue in Makkah, Saudi Arabia from April to July 2004. METHODS: Clinical information and laboratory abnormalities of patients with suspected dengue infection were collected by a standardized data collection sheet and review of medical records. Dengue virus infection was confirmed by a positive IgM capture ELISA or RT-PCR. RESULTS: Of the 160 clinically suspected patients, 91 were confirmed (64 by IgM ELISA, 14 by RT-PCR and 13 by both) to have dengue virus infection. Dengue serotypes 2 and 3 were identified in 19 and 4 patients respectively. Most patients were young adults with median age of 26 (range=6-94) years and male:female ratio of 1.5:1. The common symptoms were fever (100%), malaise (83%), musculoskeletal pain (81%), headache (75%), nausea (69%), vomiting (65%) and abdominal pain (48%). According to World Health Organization (WHO) classification (10 patients were excluded due to lack of serial hematocrits), 75 (93%) had dengue fever (DF) and 6 (7%) had dengue hemorrhagic fever (DHF). Only one patient with DHF was in pediatric age group. Twenty-one patients (5 with DHF and 16 with DF) developed one or more clinical complications that included bleeding (14), shock (4), seizures (3), acute renal failure (2), meningo-encephalitis (1), and secondary bacterial infection (1). Only one patient with shock had dengue shock syndrome (DSS) by WHO classification. Development of clinical complications was significantly associated with absence of musculoskeletal pain (p-value=0.03), lower platelet counts (p-value=0.03) and higher serum aspartate aminotransferase levels (p-value=0.04). The median duration of symptoms and hospitalization was 8 days (range=3-18) and 4 days (range=1-10) respectively. No mortality was noted. CONCLUSION: Occurrence of dengue virus infection in Makkah, Saudi Arabia is documented. Continued surveillance and effective vector control programs are warranted due to unique population dynamics of Makkah that receives millions of pilgrims annually from all over the world.