Last week, I reported on the bump in Covid-19 notifications in Tairāwhiti from the Rhythm & Vines Festival. The 7-day average of reported cases peaked at 16 on 10 January and has dropped each day this week to 8 on 25 January 2024:
The weekly chart shows the decline, especially in first infections:
Covid hospitalisations have remained low: only one this week and total of 6 for January to date, compared to 12 and 8 for November and December, respectively.
Local wastewater data is again not available this week, but national data for week ending 21 January shows declines in line with decline in cases:
Other notifications
A TB notification in a person born overseas is under infestation - likely infected in childhood, but need to clarify source and follow up close contacts to check for any spread.
Three enteric infections (two Campylobacter and one each of STEC and Yersinia) and two cases of malaria who had been overseas in a high incidence country. Before these two cases, the last three cases of malaria notified in our district were in 2018, 2007 and 2000.
Malaria
The disease was named with the implication that it was caused by ‘bad air’ - miasma theory of disease. Then we learnt about microorganisms that cause this and other infections. Malaria is caused by a single-cell parasite called Plasmodium. It spread through mosquito bites from an infected infected person to those subsequently bitten by the infected mosquito. Only some types of mosquito can carry the parasite, and these are not present in Aotearoa (NZ).
(Climate change is expanding where these mosquitos can establish themselves, and one of the functions of our national public health service is to is to monitor mosquito species at international ports, including Gisborne.)
Global control programmes have led to reductions in malaria since 2000, especially for our two Pacific Island neighbours with the highest incidence (Solomon Islands and Papua New Guinea):
But progress has reversed during the pandemic. WHO reports 249 million cases of malaria in 2022 compared to 244 and 233 million cases for 2021 and 2019, respectively.
In line with improving control globally, NZ notifications declined in the 2010s, with further declined in 2020 and 2021 from pandemic travel restrictions and a large rebound in 2023:
We already have 6 cases notified nationally for 2024 to date, that would lead to an even higher count in 2024 if continues.
Reminder to think of malaria prevention if you are travelling (. W=The Belgian Institute of Tropical Research provides travel advice to public and health professionals on travel risk, and specifically for malaria, including this helpful map of risk at December 2023:
As implied in the map, changing behaviours to prevent mosquito bites is at least as important as the anti-malarial drugs (chemoprophylaxis).
The NZ official travel advice site has a health page.
Covid-19 annual data
EpiSurv notification data of Covid-19 cases by year, with percentage of national cases in our district; noting that our population is 1% of national.
We had no Covid cases after the initial four during the first lock down until December 2021 with 3 connected cases. Fo3 2020, we were in line with national notifications, but slightly more in 2021.
Using a log scale for national notifications helps to compare monthly variation across the years. No clear pattern emerges; this is not a seasonal virus but there are monthly differences that are 2-fold or more - noting that one line is doubling of cases.
And the variation in percentage of national cases from our district:
Next week
I will look at annual data for other notifications. As always, look forward to your feedback and suggestions; and any questions on the data. Thank-you!