Surveillance for arboviruses and leptospirosis among non-malarial acute febrile illness outpatients in areas affected by Cyclones Idai and Kenneth in Mozambique

Abstract

The floods associated with the landfall of cyclones Idai and Kenneth in Mozambique between March and April 2019 had a major impact on the country’s public health and placed the affected population at risk for vector- and rodent-borne diseases. Aiming to improve the diagnostic capacity, yield information to guide public health responses, and assess potential short-term effects of cyclones Idai and Kenneth on arboviruses (dengue, Zika, and chikungunya) and leptospirosis, a clinical and laboratory surveillance for non-malarial acute febrile illness was established in six health units located in different districts within the two provinces (Sofala and Cabo Delgado) affected by the cyclones. Patients were tested using real-time reverse transcriptase polymerase chain reaction (qRT-PCR) for dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viruses and using enzyme linked immunoassays (ELISA) to detect nonstructural DENV protein 1 (NS1), as well as DENV, ZIKV, CHIKV, and Leptospira IgM antibodies. From April to September 2019, 305 patients aged ≥15 years were enrolled, of which 58.4% were women and the median age was 30 years old. All patients were qRT-PCR negative for the targeted arboviruses, but three (1.0%) were positive for DENV NS1 ELISA. Specific IgM antibodies against DENV, ZIKV, CHIKV or Leptospira were found in the serum of 104 (34.1%) patients. Our results indicate that vector- and rodent-borne disease transmission occurred in all districts under investigation in the wake of cyclones Idai and Kenneth, including some regions where cases had not been previously detected. The investigation provided useful information for post-cyclone emergency response purposes.

A Cross Sectional Study on the Bidirectional Interactions Between Leptospirosis and HIV Infection Among Patients from Maputo Central Hospital, Mozambique

“…31 Its geographical location predisposes the country to extreme weather events such as heavy floods, cyclones, storms, floods, and drought, which in turn exacerbate the burden of climate-sensitive diseases due to contamination of water and food. 19 Maputo City, the country's capital, has approximately 1.12 million inhabitants with half of the population residing in unplanned settlements, leading to high population density and poor access to basic safe drinking water and sewage drainage. 32 We conducted a cross-sectional study between March 2020 and October 2021 in Maputo Central Hospital, the largest referral hospital in the country, which also serves as a teaching hospital for undergraduate students at Eduardo Mondlane University, Faculty of Medicine and for training of specialists and other health professionals such as nurses and physician technicians.…”

“…7 The seroprevalence of Leptospira found in our study is higher than that reported from other studies done in Mozambique among febrile patients. 19,35 In these studies, the seroprevalence of Leptospira varied from 1.3% using the MAT assay to between 11.5% and 34.1% using ELISA IgM. We did not test for IgM antibodies due to financial limitations.…”

“…The frequent flooding leads to contamination of drinking water sources and food, especially fresh vegetables sold at informal markets for displaced populations. 19,32,35,41,42 For instance, a study done with the aim to assess the profile and frequency of parasites contaminating lettuce and cabbages sold in some selected markets in Maputo city found that 84% of samples were contaminated with parasites. 32 Serology, Demographics and Selected HIV Related Factors…”

“…17 Symptoms and signs of the disease may vary widely from symptomatic to subclinical (asymptomatic in 80% to 90% of cases) or self-limited anicteric febrile illness, leading to overlap with other febrile illnesses common in the region such as malaria, brucellosis, dengue, typhoid fever, babesiosis, and rickettsiosis. 7,18,19 The acute stage of the disease may be accompanied by headache, myalgia, arthralgia, chills, nausea, abdominal pain, diarrhea, cough, conjunctivitis, and skin rashes, which may appear 2 to 20 days after exposure. 13 Sub-acute and chronic complications as well as long-term sequelae may also occur.…”

Emerging Zoonotic Diseases among Pastoral Communities of Caia and Búzi Districts, Sofala, Mozambique: Evidence of Antibodies against Brucella, Leptospira, Rickettsia, and Crimean-Congo Hemorrhagic Fever Virus

“…Transmission can occur when infected urine is in contact with skin cuts and abrasions and inhalation of contaminated aerosols [11,12]. Studies that were conducted in Mozambique by Ribeiro et al (2017) and Mugabe et al (2023) have shown leptospirosis among non-malaria febrile patients in the southern, and central regions of the country [13,14]. According to Comia et al pathogenic species of Leptospira was identified in rodents using molecular methods in the northern Nampula province.…”